Optical generation system with a CCT-adjustable laser

Abstract

The present invention is an optical generation system 1000 having a first optical generation device 110, a second optical generation device 120, a luminescence material 200, a first optical element 410, and a control system 300, wherein the first optical generation device 110 is configured to generate a blue first device light 111, the first optical generation device 110 has one or more of a laser diode and a superluminescent diode, the second optical generation device 120 is configured to generate a red second device light 121, the second optical generation device 120 has one or more of a laser diode and a superluminescent diode, the luminescence material 200 is configured downstream of the first optical generation device 110, the luminescence material 200 is configured to convert at least a part of the first device light 111 into a luminescence material light 201 having one or more wavelengths within the green to yellow wavelength range, the first optical element 410 is configured to be in a light receiving relationship with the first optical generation device 110 and the luminescence material 200, (i) the first optical element 410 has a controllable wavelength-dependent transmittance in the blue wavelength range, and / or (ii) the first optical element 410 has a controllable wavelength-dependent reflectance in the blue wavelength range, the optical generation system 1000 is configured to generate a system light 1001 including one or more of the first device light 111, the second device light 121, and the luminescence material light 201, the control system 300 is configured to control the spectral power distribution of the system light 1001 by controlling the first optical element 410, the control system 300 is configured to control the correlated color temperature of the system light 1001 to a value selected from the range of 1800 to 6500 K, and the correlated color temperature of the system light 1001 is controllable over a CCT control range of at least 250 K within the range of 1800 to 6500 K, thereby providing an optical generation system 1000.

Description

Technical Field

[0001] The present invention relates to a light generation system. The present invention further relates to an illumination device having the light generation system.

Background Art

[0002] Illumination systems are known in the art. For example, US2009 / 0122530 describes a solid-state lighting system that provides improved color quality and / or color contrast (according to US2009 / 0122530). The system supplies total light with a delta chroma value for each of 15 color samples of a preselected color quality scale so as to provide improved color contrast compared to an incandescent or blackbody light source according to a specified value that depends on the color temperature (according to US2009 / 0122530). The illumination system provided in US2009 / 0122530 may have one or more organic electroluminescence elements, or may have a plurality of inorganic light-emitting diodes in which at least two inorganic light-emitting diodes have different emission bands. WO2021 / 052900A1 discloses a light generation device configured to generate white device light, the light generation device having: (i) a first light source configured to generate blue first source light, the first light source being a first light source that is a first laser light source; (ii) a first luminescence material configured to convert a part of the blue first source light into first luminescence material light having an emission band having a wavelength in one or more of green and yellow; (iii) an optical filter configured to optically filter the first luminescence material light into optically filtered first luminescence material light, the optically filtered first luminescence material light being red-shifted with respect to the first luminescence material light; and (iv) a second light source configured to generate red second source light, the second light source being a second light source including a second laser light source.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Laser-based light sources have received much attention because they can generate relatively high luminous fluxes from relatively small emission areas. The high brightness of these light sources may facilitate more precise control and miniaturization of the light distribution by the optical system. Furthermore, it may be desirable to have a high-brightness light source for general lighting applications that can be adjusted over a wide range of color spaces / CCTs and has good color rendering properties. Usually, in order to obtain a color adjustment function, a combination of several light sources with different starting color points (e.g., various light sources with different phosphors, different primary colors (e.g., RGB) from direct emitters, or combinations thereof) may be required. To create a high-brightness color-tunable light source, these multiple light sources may need to be optically combined with good color mixing and without further increase in étendue. However, in the case of a system with direct RGB lasers, for example, due to the inherent narrow spectral width of the laser lines and / or due to practical limitations for a certain specific limited spectral region, without unrealistic primary laser wavelength requirements, the optical combination of multiple light sources often results in a relatively low CRI. Furthermore, in the case of a system with two or more phosphor converters, the étendue tends to increase significantly (such as at least x2 times), which may not be desirable for high-brightness applications. Furthermore, prior art systems may require a multi-channel driver and / or additional color mixing. Furthermore, it may be desirable to use generally available light sources rather than requiring special equipment.

[0004] Accordingly, providing an alternative light generation system is an aspect of the present invention, and the alternative light generation system preferably further at least partially removes one or more of the above disadvantages. The present invention may aim to eliminate or improve at least one of the disadvantages of the prior art or to provide a useful alternative means.

Means for Solving the Problems

[0005] According to a first aspect, the present invention provides a light generation system (the "system") having a first light generation device, a second light generation device, a luminescence material, a first optical element, and a control system. In an embodiment, the first light generation device may be configured to generate blue first device light (or "first device light"). In contrast, in an embodiment, the second light generation device may be configured to generate red second device light (or "second device light"). In a further embodiment, the first light generation device may have one or more of a laser diode and a superluminescent diode, particularly a laser diode, or particularly a superluminescent diode. Similarly, in an embodiment, the second light generation device may have one or more of a laser diode and a superluminescent diode, particularly a laser diode, or particularly a superluminescent diode. In an embodiment, the luminescence material may be arranged downstream of the first light generation device, and the luminescence material is configured to convert at least a part of the first device light into luminescence material light. The luminescence material light may particularly have one or more wavelengths within the green-yellow wavelength range. In a further embodiment, the first optical element may be configured to be in a light receiving relationship with the first light generation device and the luminescence material, particularly (i) the first optical element has a controllable wavelength-dependent transmittance in the blue wavelength range, and / or (ii) the first optical element has a controllable wavelength-dependent reflectance in the blue wavelength range. Accordingly, in an embodiment, the light generation system may be configured to generate system light including one or more of the first device light, the second device light, and the luminescence material light. In an embodiment, the control system may be configured to control the spectral power distribution of the system light by controlling, particularly in the operating mode of the light generation system, particularly the (at least) the wavelength-dependent transmittance of the first optical element.In a further embodiment, the control system may be configured to control the correlated color temperature (or "CCT") of the system light to a value selected from the range of 1800 to 6500 K in the operation mode, and the correlated color temperature of the system light is controllable over a CCT control range of at least 250 K within the range of 1800 to 6500 K.

[0006] The system of the present invention provides the advantage that a high CRI is provided to the high-brightness light source, which further facilitates the control of the correlated color temperature of the system light. In particular, in an embodiment, the system may have a (single) phosphor converter element, a (single) blue laser, and a (single) red laser. The red laser having emission in an actually available wavelength range is used to increase the CRI and provide a color point on the blackbody locus (BBL) for a low CCT. The system of the present invention can easily supply system light with an adjustable CCT that has adjustability in the range from 2700 K to 6500 K with a small étendue while maintaining a high CRI such as, for example, at least 80 or more.

[0007] In particular, the system light may have blue first device light, red second device light, and green-yellow luminescence material light, which can together provide a high CRI. In particular, the red second device light may further contribute to a high R9 value (red rendering). Since the first optical element can provide controllable wavelength-dependent modification, particularly transmittance or particularly reflectance, in the blue wavelength range, the relative contribution of the blue first device light in the system light can be changed, thereby changing the correlated color temperature (CCT) of the system light. Further, the relative contribution of the red second device light in the system light can be changed according to, for example, the change in the relative contribution of the blue first device light, so as to lead to a specific color point such as a color point on the BBL. The light generation system of the present invention, in certain embodiments, has at least one blue laser, a phosphor conversion element that receives laser pump light and provides white light with a high CCT (not necessarily on the BBL), an optical system for collecting and pre-collimating the phosphor-converted light including the partially transmitted blue light, a spectral filtering element disposed after the collimating optical system, which transmits the green-yellow converted light and has the possibility of partially suppressing the blue laser light according to its orientation, a red laser added to / combined with the main optical path of the phosphor conversion light source, and means for adjusting the transmittance of the blue light after phosphor conversion, such as by changing the angle of the spectral filtering element with respect to the main optical axis.

[0008] In certain embodiments, the present invention is a light generation system having a first light generation device, a second light generation device, a luminescence material, a first optical element, and a control system, wherein the first light generation device is configured to generate a first device light of blue color, the first light generation device has one or more of a laser diode and a superluminescent diode, the second light generation device is configured to generate a second device light of red color, the second light generation device has one or more of a laser diode and a superluminescent diode, the luminescence material is configured downstream of the first light generation device, the luminescence material is configured to convert at least a part of the first device light into a luminescence material light having one or more wavelengths within the green-yellow wavelength range, the first optical element is configured to be in a light receiving relationship with the first light generation device and the luminescence material, (i) the first optical element has a controllable wavelength-dependent transmittance in the blue wavelength range, and / or (ii) the first optical element has a controllable wavelength-dependent reflectance in the blue wavelength range, the light generation system is configured to generate a system light including one or more of the first device light, the second device light, and the luminescence material light, the control system is configured to control the spectral power distribution of the system light by controlling the wavelength-dependent transmittance of the first optical element, the control system is configured to control the correlated color temperature of the system light to a value selected from the range of 1800 to 6500 K, and the correlated color temperature of the system light can be controlled over a CCT control range of at least 250 K within the range of 1800 to 6500 K, thereby providing a light generation system.

[0009] Accordingly, the present invention can provide a light generation system. In particular, the light generation system may be configured to supply system light. In particular, the light generation system may have a first light generation device and a second light generation device.

[0010] In an embodiment, the first light generation device may be configured to generate first device light that is blue, i.e., first device light including a (center) wavelength in the blue wavelength range. The term "blue light" or "blue emission" particularly relates to light having a wavelength within the range of about 440 to 495 nm (including some purple and cyan hues). Accordingly, in an embodiment, the first light generation device may be configured to generate first device light having a (center) wavelength within the range of (about) 440 to 495 nm. In a further embodiment, at least 80%, such as at least 90%, of the spectral power of the first device light may fall within the range of 440 to 495 nm. In particular, the first light generation device may include a first light source configured to supply the (blue) first device light.

[0011] In a further embodiment, the second light generation device may be configured to generate second device light that is red, i.e., second device light including a (center) wavelength in the red wavelength range. The term "red light" or "red emission" particularly relates to light having a wavelength within the range of about 620 to 780 nm. Accordingly, in an embodiment, the second light generation device may be configured to generate second device light having a (center) wavelength within the range of (about) 620 to 780 nm. In a further embodiment, at least 80%, such as at least 90%, of the spectral power of the second device light may fall within the range of 620 to 780 nm. In particular, the second light generation device may include a second light source configured to supply the (blue) first device light.

[0012] In an embodiment, the first light generation device may particularly have one or more of a laser diode and a superluminescent diode, particularly at least a laser diode, or particularly at least a superluminescent diode. Similarly, in an embodiment, the second light generation device may have one or more of a laser diode and a superluminescent diode, particularly at least a laser diode, or particularly at least a superluminescent diode.

[0013] The term "laser" particularly refers to a device that emits light through a process of optical amplification based on stimulated emission of electromagnetic radiation. Particularly, in an embodiment, the term "laser" may refer to a solid-state laser. In a specific embodiment, the term "laser" or "laser light source", or a similar term, may refer to a laser diode (or diode laser).

[0014] Therefore, in an embodiment, the first light generation device (or the second light generation device), particularly the first light source (or the second light source), may have a laser light source. In an embodiment, the term "laser" or "solid-state laser" refers to cerium-doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF), chromium-doped chrysoberyl (alexandrite) laser, chromium ZnSe (Cr:ZnSe) laser, divalent samarium-doped calcium fluoride (Sm:CaF2) laser, Ce:YAG laser, Er:YAG laser, erbium-doped and erbium-ytterbium codoped glass laser, F-center laser, holmium YAG (Ho:YAG) laser, Nd:YAG laser, NdCrYAG laser, neodymium-doped yttrium calcium oxoborate Nd:YCa4O(BO3)3 or Nd:YCOB, neodymium-doped yttrium orthovanadate (Nd:YVO4) laser, neodymium glass (Nd:glass) laser, neodymium YLF (Nd:YLF) solid-state laser, 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+ ) laser, trivalent uranium-doped calcium fluoride (U:CaF2) solid-state laser, ytterbium-doped glass laser (rod, plate / chip, and fiber), ytterbium YAG (Yb:YAG) laser, Yb2O3 (glass or ceramics) laser, etc., may refer to one or more of them.

[0015] In an embodiment, the term "laser" or "solid-state laser" may refer to one or more of semiconductor laser diodes such as GaN, InGaN, AlGaInP, AlGaAs, InGaAsP, lead salts, vertical cavity surface emitting laser (VCSEL), quantum cascade laser, hybrid silicon laser, etc.

[0016] The laser may be combined with an upconverter to reach a shorter (laser) wavelength. For example, upconversion can be achieved with some (trivalent) rare earth ions, or upconversion can be achieved with a nonlinear crystal. In other examples, a laser such as a dye laser may be combined with a downconverter to reach a longer (laser) wavelength.

[0017] As can be derived from the following description, the term "laser light source" may refer to a plurality of (different or identical) laser light sources. In certain embodiments, the term "laser light source" may refer to a plurality of N (identical) laser light sources. In an embodiment, N is 2 or more. In certain embodiments, N can be at least 5, such as at least 8 in particular. In this way, higher brightness can be obtained. In an embodiment, the laser light source may be disposed within a laser bank (see also the above). The laser bank may include, in an embodiment, a heat sink and / or an optical system, for example, a lens for collimating the laser light. In a further embodiment, the first light generation device may have a single light source. Similarly, in an embodiment, the second light generation device may have a single light source.

[0018] The first laser light source (or the second laser light source) may be configured to generate laser light source light (or "laser light"). The source light may essentially consist of the laser light source light. The source light may also have the laser light source light of two or more (different or identical) laser light sources. For example, the laser light source light of two or more (different or identical) laser light sources may be coupled to an optical waveguide to supply a single light beam having the laser light source light of the two or more (different or identical) laser light sources. Thus, in certain embodiments, the source light is, in particular, collimated source light. In still other embodiments, the source light is, in particular, (collimated) laser light source light.

[0019] In embodiments, the laser source light may have one or more bands having a bandwidth as is known for lasers. In certain embodiments, the band may be a relatively sharp line, such as having a full width half maximum (FWHM) within a range of less than 20 nm at room temperature (RT), such as 10 nm or less. Accordingly, the source light may have a spectral power distribution (intensity in an energy scale as a function of wavelength) that may include one or more (narrow) bands. In particular, in embodiments, the first light generation device may be configured to supply first device light having an FWHM of 20 nm or less, such as 10 nm or less, especially at room temperature, i.e., in embodiments, the first device light may have an FWHM of 20 nm or less, such as 10 nm or less, especially at room temperature. In further embodiments, the second light generation device may be configured to supply the second device light having an FWHM of 20 nm or less, such as 10 nm or less, especially at room temperature, i.e., in embodiments, the second device light may have an FWHM of 20 nm or less, such as 10 nm or less, especially at room temperature.

[0020] The beam of (source light) 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 in an individual converter region, or may be slightly upstream or slightly downstream of the individual converter region. In particular, the focusing and / or collimation may be such that the cross-sectional shape of the beam in the individual converter region (perpendicular to the optical axis) is not essentially larger than the cross-sectional shape of the individual converter region (perpendicular to the optical axis) at the location where the source light irradiates the individual converter region. Focusing may be performed by one or more optical systems such as a (focusing) lens. In particular, two lenses may be applied to focus the laser source light. Collimation may be performed by one or more (other) optical systems such as a collimation element like a lens and / or a parabolic mirror. In an embodiment, the beam of (laser) source light may be relatively highly collimated, such as ≦2° (FWHM), more particularly ≦1° (FWHM), and most particularly ≦0.5° (FWHM) in the embodiment. Thus, ≦2° (FWHM) may be regarded as (highly) collimated source light. An optical system may be used to provide (high) collimation (see also above).

[0021] Superluminescent diodes are known in the art. A superluminescent diode can be shown as a semiconductor device that has brightness comparable to that of a laser diode and can potentially emit low-coherence light with a broad spectrum like an LED. US2020192017 shows, for example, that "currently, a single SLED can emit light over a bandwidth of, for example, up to 50 to 70 nm in the wavelength range of 800 to 900 nm with sufficient spectral flatness and sufficient output." In the visible range used for display applications, i.e., in the wavelength range of 450 to 650 nm, a single SLED can currently emit light over a bandwidth of up to 10 to 30 nm. These emission bandwidths are too small for display or projector applications that require red (640 nm), green (520 nm), and blue (450 nm), i.e., RGB emission. Further, superluminescent diodes are described, inter alia, in Chapter 9.3, superluminescent diodes of "Edge Emitting Laser Diodes and Superluminescent Diodes", first published on August 3, 2020, with the authors being Szymon Stanczyk, Anna Kafar, Dario Schiavon, Stephen Najda, Thomas Slight, Piotr Perlin and the book editors being Fabrizio Roccaforte, Mike Leszczynski, available at https: / / doi.org / 10.1002 / 9783527825264.ch9. This book, particularly Chapter 9.3, is incorporated herein by reference. In the said book, it is shown, inter alia, that a superluminescent diode (SLD) is an emitter that combines the characteristics of a laser diode and a light-emitting diode. The SLD emitter utilizes stimulated emission. This means that these devices operate at a current density similar to that of a laser diode.The main difference between an LD and an SLD is that in the latter case, the device waveguide may be designed in a special way to prevent the formation of standing waves and laser oscillation. Nevertheless, the presence of the waveguide ensures the emission of a high-quality optical beam with a high spatial coherence of light, which, at the same time, is characterized by a low temporal coherence. Currently, the most successful designs of nitride SLDs are curved, bent, or tilted waveguide geometries, and tilted facet geometries, while in all cases, as shown in Fig. 9.10, the front end of the waveguide is in inclined contact with the device facet. The tilted waveguide suppresses the reflection of light by directing the light from the facet to the waveguide outward into the lossy unpumped area of the device chip. Thus, an SLD can be, in particular, a semiconductor light source in which spontaneous emission light is amplified by stimulated emission in the active region of the device. Such emission is called "superluminescence". A superluminescent diode combines the high output and brightness of a laser diode with the low coherence of a conventional light-emitting diode. The low (temporal) coherence of the semiconductor light source has the advantages that the speckle is significantly reduced or invisible, and that the spectral distribution of the emission is much broader than that of a laser diode, and the broader spectral distribution may be more suitable for lighting applications. In particular, by changing the current, the spectral power distribution of the superluminescent diode can be changed. In this way, the spectral power distribution can be controlled (see, for example, Optics Express Vol. 26, Issue 20, pp. 26355-26364, https: / / doi.org / 10.1364 / OE.26.026355 by Abdullah A. Alatawi et al. as well).

[0022] In an embodiment, the light generation system may have a luminescence material. In particular, the luminescence material may be configured downstream of the first light generation device with respect to the first device light, i.e., the luminescence material may be arranged to be in a light receiving relationship with the first light generation device. In particular, the first light generation device may be configured to supply the first device light along a first device optical path, optionally via one or more optical elements such as transmissive and / or reflective optical elements, and the luminescence material may be arranged (at least partially) within the first device optical path.

[0023] The luminescence material may in particular be configured to convert at least a part of the first device light into luminescence material light. In an embodiment, the luminescence material light may in particular have one or more wavelengths within the green to yellow wavelength range. The term "green light" or "green emission" relates in particular to light having a wavelength within the range of about 495 to 570 nm. The term "yellow light" or "yellow emission" relates in particular to light having a wavelength within the range of about 570 to 590 nm. Thus, the term "green to yellow light" or "green to yellow emission" may in particular relate to light having a wavelength within the range of (about) 495 to 590 nm. Thus, in an embodiment, the luminescence material may be configured to convert at least a part of the first device light into luminescence material light having a (center of gravity) wavelength within the range of 495 to 590 nm. In a further embodiment, at least 80%, such as at least 90%, of the spectral power of the luminescence material light may fall within the range of 495 to 590 nm.

[0024] The term "luminescence material" particularly refers to a material that can convert first device light, particularly blue light, into luminescence material light. Generally, the first device light and the luminescence material light have different spectral power distributions. Accordingly, instead of the term "luminescence material", the terms "luminescence converter" or "converter" may be applied. Generally, the luminescence material light has a spectral power distribution at a wavelength greater than that of the first device light, which is the case of so-called down-conversion. In embodiments, the "luminescence material" may particularly refer to a material that can convert radiation, for example, into visible light. For example, in embodiments, the luminescence material may be able to convert blue light into visible light. Accordingly, when excited by blue light, the luminescence material may emit radiation. Generally, the luminescence material is a down-converter, i.e., short-wavelength radiation is converted into radiation having a longer wavelength (λex < λem).

[0025] In embodiments, the term "luminescence" may refer to phosphorescence. In embodiments, the term "luminescence" may also refer to fluorescence. Instead of the term "luminescence", the term "light emission" may be applied. Accordingly, the terms "first device light" and "luminescence material light" may respectively refer to excitation radiation and light emission (radiation). Similarly, the term "luminescence material" may, in embodiments, refer to a phosphorescent material and / or a fluorescent material.

[0026] The term "luminescence material" may also refer to a plurality of different luminescence materials. Examples of possible luminescence materials are shown below. Accordingly, the term "luminescence material" may, in certain embodiments, refer to a luminescence material composition.

[0027] For example, A3B5O 12: Experiments were carried out with various luminescence materials from the group of Ce. In particular, (i) a first light generating device having a first centroid wavelength selected from the group including 445 nm, 450 nm, 455 nm and 460 nm, (ii) a second light generating device having a second centroid wavelength selected from the group including 630 nm, 632 nm, 634 nm, 636 nm, 638 nm and 640 nm, and (iii) A3B5O 12 : Tests were carried out with combinations of luminescence materials selected from the group containing Ce. It will be apparent to those skilled in the art that the selection of the centroid wavelength and the phosphor may depend on the desired CCT, CRI and R9. For CCT values in the range of 2700 to 4000 K, A3B5O 12 : With luminescence materials selected from the group of Ce, particularly good results were obtained (over the indicated centroid wavelengths of the first and second light generating devices). Thus, in an embodiment, the luminescence material is A3B5O 12 : may be selected from the group of Ce.

[0028] In an embodiment, the luminescence materials may each be selected from garnets and nitrides, particularly doped with trivalent cerium or divalent europium. The term "nitride" may also refer to oxynitrides or nitridosilicates, etc. It should be noted that the term "luminescence material" may also refer to a combination of two or more different luminescence materials.

[0029] As described above, in a particular embodiment, the luminescence material is A3B5O 12:Comprising a Ce-type luminescence material, A, in embodiments, comprises one or more of Y, La, Gd, Tb, and Lu, particularly (at least) one or more of Y, Gd, Tb, and Lu, and 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, such as particularly one or more of Y and Lu. In particular, B may comprise at least one of Al and Ga, more particularly may comprise at least Al, such as essentially only Al. Thus, a particularly suitable luminescence material may be a cerium comprising garnet material. Garnet embodiments particularly have A3B5O 12 comprising garnet, A comprises at least yttrium or lutetium, and B comprises at least aluminum. Such garnet may be doped with cerium (Ce), praseodymium (Pr), or a combination of cerium and praseodymium, but particularly may be doped with Ce. In particular, B comprises aluminum (Al), but B may also partially comprise gallium (Ga) and / or scandium (Sc) and / or indium (In), particularly up to about 20% of Al, more particularly up to about 10% of Al (i.e., B ions essentially consist of 90 mol% or more of Al and one or more of Ga, Sc, and In of 10 mol% or less). B may particularly comprise up to about 10% of gallium. In another variant, B and O may be at least partially replaced by Si and N. Element A may particularly be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb), and lutetium (Lu). Further, Gd and / or Tb particularly only exist in an amount of up to about 20% of A. In certain embodiments, the garnet luminescence material is (Y 1-x Lu x )3B5O 12 :Ce, where x is 0 or more and 1 or less. The term ":Ce" indicates that a part of the metal ions in the luminescence material (i.e., in garnet, a part of the "A" ions) is replaced by Ce. For example, (Y 1-xLu x )3Al5O 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 generally replaces A by 10% or less, and generally, the Ce concentration is in the range of 0.1 to 4%, particularly 0.1 to 2% (relative to A). Assuming 1% Ce and 10% Y, the complete and detailed formula is (Y 0.1 Lu 0.89 Ce 0.01 )3Al5O 12 can be. Ce in garnet is substantially in the trivalent state or only in the trivalent state, as is known to those skilled in the art.

[0030] In an embodiment, the luminescence material (therefore) contains A3B5O 12 and up to 10% of B - O can be replaced by Si - N.

[0031] In a further embodiment, A may have one or more of Gd and Lu, and B may have at least 90 at.% of Al. In a further embodiment, the luminescence material may have 0.1 to 2 at.% of cerium relative to A.

[0032] In a further embodiment, the luminescence material may contain (Y x1 A' x2 Ce x3 )3(Al y1 B' y2 )5O 12 , where x1 + x2 + x3 = 1, x3 > 0, 0 < x2 + x3 ≤ 0.2, y1 + y2 = 1, 0 ≤ y2 ≤ 0.2, A' contains one or more elements selected from the group consisting of lanthanides, and B' contains one or more elements selected from the group consisting of Ga, In, and Sc. In an embodiment, x3 is selected from the range of 0.001 to 0.1. In the present invention, in particular, x1 > 0, such as at least 0.8, such as x1 > 0.2. Garnet with Y can provide an appropriate spectral power distribution.

[0033] In further embodiments, up to 10% of B-O can be replaced by Si-N. Here, B in B-O refers to one or more of Al, Ga, In, and Sc (and O refers to oxygen), and in certain embodiments, B-O may refer to Al-O. As noted above, in certain embodiments, x3 can be selected from the range of 0.001 to 0.04. In particular, such luminescent materials have an appropriate spectral distribution (see below), relatively high efficiency, 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)). Accordingly, in certain embodiments, A can be selected from the group consisting of Lu and Gd. Alternatively, or in addition, B can include Ga. Accordingly, in embodiments, the luminescent material is (Y x1 (Lu,Gd) x2 Ce x3 )3(Al y1 Ga y2 )5O 12 and may include Lu and / or Gd. Even more particularly, x3 is selected from the range of 0.001 to 0.1, 0 < x2 + x3 ≤ 0.1, and 0 ≤ y2 ≤ 0.1. Further, in certain embodiments, up to 1% of B-O can be replaced by Si-N. Here, the percentage refers to moles (as is known in the art), and see, for example, EP3149108 as well. In still other particular embodiments, the luminescent material is (Y x1 Ce x3 )3Al5O 12 where x1 + x3 = 1, 0 < x3 ≤ 0.2, and is, for example, 0.001 to 0.1, etc.

[0034] In certain embodiments, the light generating device may only include a luminescent material selected from the type of garnet containing cerium. In still other particular embodiments, the light generating device is (Y x1 A' x2 Ce x3 )3(Al y1 B'y2 )5O 12 and includes a single type of luminescence material such as. Thus, in certain embodiments, the light generating device has a luminescence material, and at least 85% 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 A' x2 Ce x3 )3(Al y1 B' y2 )5O 12 wherein A' includes one or more elements selected from the group consisting of lanthanides, B' includes one or more elements selected from the group consisting of Ga, In, and Sc, x1 + x2 + x3 = 1, x3 > 0, 0 < x2 + x3 ≤ 0.2, y1 + y2 = 1, and 0 ≤ y2 ≤ 0.2. In particular, x3 is selected from the range of 0.001 to 0.1. It should be noted that in an embodiment, x2 = 0. Instead, or in addition, in an embodiment, y2 = 0.

[0035] In certain embodiments, A may particularly include at least Y, and B may particularly include at least Al.

[0036] Instead, or in addition, the luminescence material may include a luminescence material of the A3Si6N 11 :Ce 3+ type, and A includes one or more of Y, La, Gd, Tb, and Lu, such as one or more of La and Y in an embodiment.

[0037] In an embodiment, the luminescence material may instead, or in addition, be MS:Eu 2+ and / or M2Si5N8:Eu 2+ and / or MAlSiN3:Eu 2+ and / or Ca2AlSi3O2N5:Eu 2+and the like, where M comprises one or more of Ba, Sr, and Ca, and in particular embodiments, at least Sr. Thus, in embodiments, the luminescent material may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu, and (Ba,Sr,Ca)2Si5N8:Eu. In these compounds, europium (Eu) is substantially or exclusively divalent, replacing one or more of the indicated divalent cations. 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, if we assume 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, particularly 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 in this compound includes calcium or strontium, or calcium and strontium, more particularly calcium. Here, 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 in this compound includes Sr and / or Ba. In a further particular embodiment, M consists of Sr and / or Ba (not taking into account the presence of Eu), Ba 1.5 Sr 0.5Specifically, the material Si5N8:Eu (i.e., 75% Ba; 25% Sr) is composed of 50 to 100%, more particularly 50 to 90% Ba, and 50 to 0%, particularly 50 to 10% Sr. Here, 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 be denoted as MAlSiN3:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca). In particular, M in this compound includes calcium or strontium, or calcium and strontium, more particularly calcium. Here, Eu is introduced to replace at least a portion of M (i.e., one or more of Ba, Sr, and Ca). As known to those skilled in the art, Eu in the above luminescent materials is substantially or exclusively in a divalent state.

[0038] In embodiments, the red luminescent material may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu, and (Ba,Sr,Ca)2Si5N8:Eu. In these compounds, europium (Eu) is substantially or exclusively divalent, replacing one or more of the indicated divalent cations. 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 cations it replaces. The term ":Eu" indicates that a portion of the metal ions are Eu (in these examples, Eu 2+ For example, if we assume 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.

[0039] Eu in the above luminescence material is substantially in a divalent state or exists only in a divalent state, as is known to those skilled in the art.

[0040] The blue luminescence material may include YSO (Y2SiO5:Ce 3+ ), or a similar compound, or BAM (BaMgAl 10 O 17 :Eu 2+ ), or a similar compound.

[0041] As used herein, the term "luminescence material" particularly relates to inorganic luminescence materials. Instead of the term "luminescence material", the term "phosphor" may be applied. These terms are known to those skilled in the art.

[0042] Alternatively or in addition, other luminescence materials may be applied. For example, quantum dots and / or organic dyes may be applied and optionally embedded in a permeable matrix such as a polymer such as PMMA or polysiloxane.

[0043] Quantum dots are generally small crystals of semiconductor materials having a width or diameter of only a few nanometers. When excited by incident light, quantum dots emit light of a color determined by the size and material of the crystal. Therefore, by adapting the size of the dots, light of a specific color can be generated. The most well-known quantum dots that emit light in the visible range are based on cadmium selenide (CdSe) with a shell such as cadmium sulfide (CdS) and zinc sulfide (ZnS). Indium phosphide (InP), as well as cadmium-free quantum dots such as copper indium sulfide (CuInS2) and / or silver indium sulfide (AgInS2), can also be used. Quantum dots exhibit a very narrow emission band, and thus, quantum dots show saturated colors. Furthermore, the emission color can be easily adjusted by adapting the size of the quantum dots. In the present invention, any type of quantum dots 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 with a very low cadmium content.

[0044] Instead of or in addition to quantum dots, other quantum confinement structures may be used. "Quantum confinement structure" should be understood, in the context of the present application, as, for example, quantum wells, quantum dots, quantum rods, tripods, tetrapods, or nanowires.

[0045] Organic phosphors can also be used.

[0046] Different luminescence materials can have respective luminescence material light of different spectral power distributions. Instead of or in addition, such different luminescence materials can, in particular, have different color points (or dominant wavelengths).

[0047] As noted above, other luminescence materials may also be possible. Thus, in certain embodiments, the luminescence material is selected from the group consisting of divalent europium-containing nitrides, divalent europium-containing oxynitrides, divalent europium-containing silicates, garnets containing cerium, and quantum structures. Quantum structures can include, for example, quantum dots or quantum rods (or other quantum-type particles) (see above). Quantum structures can also include quantum wells. Quantum structures can also include photonic crystals.

[0048] In an embodiment, the luminescence material may be included in the luminescence body. In particular, the luminescence material is included in the luminescence body. The luminescence body may be a layer such as a self-supporting layer. The luminescence body may also be a coating. The luminescence body may have a luminescence coating on a support (in particular, a light-transmissive support in the transmission mode or a reflective support in the reflection mode). In particular, the luminescence body may be essentially self-supporting. In an embodiment, the luminescence material may be provided as a luminescence body such as a luminescence single crystal, a luminescence glass, or a luminescence ceramic body. Such a body may sometimes be referred to as a "converter body" or a "luminescence body". In an embodiment, the luminescence body may be a luminescence single crystal or a luminescence ceramic body. For example, in an embodiment, a garnet luminescence material containing cerium may be provided as a luminescence single crystal or as a luminescence ceramic body. In other embodiments, the luminescence body may have a light-transmissive body in which the luminescence material is embedded. For example, the luminescence body may be a glass body having a glass body provided with a luminescence material embedded therein. Alternatively, the glass itself may be luminescent. In other embodiments, the luminescence body may be a polymer body having a polymer body provided with a luminescence material embedded therein. In an embodiment, the luminescence body may be a crystal, or a ceramic body, or a luminescence material dispersed in another material such as, for example, a polymer body (see also below). In a further embodiment, at least one of the one or more luminescence bodies has a ceramic body. Further, in an embodiment, at least one of the one or more luminescence bodies is (a)A3B5O 12:A Ce-type luminescent material, wherein A contains one or more of Y, La, Gd, Tb, and Lu, B contains one or more of Al, Ga, In, and Sc, and / or (b) A3Si6N 11 :Ce 3+ :A Ce-type luminescent material, wherein A contains one or more of Y, La, Gd, Tb, and Lu, and in particular, A contains one or more of La and Y. Further, in an embodiment, the one or more luminescence bodies are a single luminescence body. Thus, the system may have a single luminescence body. The luminescence body is particularly configured to receive at least a part of the first device light. Thus, in an embodiment, the luminescence body is configured downstream of the first light generation device. Further, the luminescence body can be particularly configured to be in a light receiving relationship with the first light generation device.

[0049] In an embodiment, the luminescent material may operate in a transmission mode, i.e., the light supplied to the luminescent material may essentially enter the luminescent material at a first side, (optionally, may be converted,) and exit from the luminescent material at a second side, in particular, the first side and the second side are disposed on opposite sides of the luminescent material. In a further embodiment, the luminescent material may operate in a reflection mode, i.e., the light supplied to the luminescent material may enter the luminescent material at a first side, (optionally, may be converted,) and exit from the luminescent material at the first side.

[0050] In an embodiment, the light generation system may further include a first optical element. The first optical element may be configured to be in a light receiving relationship with the first light generation device and the luminescence material, that is, the first optical element may be configured to receive at least a part of the (blue) first device light and at least a part of the luminescence material light. The first optical element may particularly provide a controllable and wavelength-dependent modification of the light supplied to the first optical element. In particular, in an embodiment, the first optical element may have a controllable wavelength-dependent transmittance in the blue wavelength range. In a further embodiment, the first optical element may have a controllable wavelength-dependent reflectivity in the blue wavelength range. Thereby, by controlling the wavelength-dependent modification of the blue first device light, particularly through transmission or particularly through reflection, the amount of blue light in the (system) light downstream of the first optical element can be controlled. Therefore, the first optical element can facilitate the control of the CCT of the system light by providing means for controlling the proportion of the blue first device light in the system light.

[0051] As will be further described below, the CCT may further be affected by the output of the second light generation device, particularly under the control of the control system.

[0052] In a further embodiment, the dichroic filter may be movable, such as tiltable or displaceable, with respect to the optical axis of the (blue) first device light. In particular, the control system is configured to control the movement, such as the position control of the dichroic filter. For example, in an embodiment, the light generation system may have an actuator configured to move the first optical element so as to tilt it or displace it. In particular, the control system is configured to control the actuator. In a further embodiment, the wavelength-dependent transmittance in the blue wavelength range may depend on the position, such as the tilt angle (α) or the displacement (d). Accordingly, the control system may be configured to control the position, thereby controlling the transmittance (or reflectance) of light in the blue wavelength range, and thereby controlling the correlated color temperature of the system light.

[0053] In an embodiment where the first optical element has a dichroic filter, the transmittance in at least a part of the blue wavelength range at the first position (p1) is at most 0.5 times the transmittance in at least a part of the blue wavelength range at the second position (p2). That is, by moving the first optical element to the first position (p1) so as to tilt it or displace it with respect to the second position (p2), the transmittance of blue light can be reduced to one half. In a further embodiment, the transmittance in at least a part of the blue wavelength range at the first position (p1) is at most 0.75 times, in particular at most 0.3 times, especially at most 0.2 times, and at most 0.4 times the transmittance in at least a part of the blue wavelength range at the second position (p2).

[0054] In an embodiment where the first optical element has a dichroic mirror, the reflectance in the blue wavelength range (at least a part thereof) at the first position (p1) is at most 0.5 times the reflectance in the blue wavelength range (at least a part thereof) at the second position (p2), that is, by moving the first optical element to the first position (p1) with respect to the second position (p2), the reflectance of blue light can be reduced to one-half. In a further embodiment, the reflectance in the blue wavelength range (at least a part thereof) at the first position (p1) is at most 0.75 times, particularly at most 0.3 times, especially at most 0.2 times, etc., at most 0.4 times the reflectance in the blue wavelength range (at least a part thereof) at the second position (p2).

[0055] In an embodiment, the first optical element may have a dichroic filter. In particular, in an embodiment, the dichroic filter may be tiltable with respect to the optical axis of the (blue) first device light. In particular, the control system is configured to control the tilt angle (α). The tilt angle may particularly refer to the angle between (i) the plane defined by the first optical element and (ii) the optical axis of the first device light (when the first device light reaches the first optical element). In a further embodiment, the wavelength-dependent transmittance in the blue wavelength range may depend on the tilt angle (α). Accordingly, the control system may be configured to control the tilt angle (α), thereby controlling the transmittance (or reflectance) of light in the blue wavelength range, and thereby controlling the correlated color temperature of the system light. For this purpose, the control system may control the actuator described above.

[0056] Similarly, in an embodiment, the first optical element may include a dichroic mirror (or “dichroic reflector”), and in particular, the dichroic mirror may be tiltable with respect to the optical axis of the (blue) first device light. In particular, the control system is configured to control the tilt angle (α). In a further embodiment, the wavelength-dependent reflectivity in the blue wavelength range may depend on the tilt angle (α).

[0057] In an embodiment, the tilt angle (α) may be controllable within a range of 0° to 90°, such as within a range of 15° to 90° (with respect to the optical axis), in particular within a range of 30° to 90°, such as within a range of 45° to 90°. Accordingly, in an embodiment, the first optical element, in particular the dichroic mirror, may be configured perpendicular to the optical axis and controllable with a maximum deviation of about 45° with respect to this optical axis. In an embodiment, a tilt of 45° may be a clockwise or counterclockwise tilt.

[0058] In an embodiment where the first optical element includes a dichroic filter, the transmittance at a first tilt angle (α1) in the blue wavelength range, in particular in at least a part of the blue wavelength range, or in particular over the entire blue wavelength range, is at most 0.5 times the transmittance in the blue wavelength range at a second tilt angle (α2), such as at least a part of the blue wavelength range. That is, by tilting the first optical element to the first tilt angle (α1) with respect to the second tilt angle (α2), the transmittance of blue light can be reduced to one half. In a further embodiment, the transmittance in the blue wavelength range at the first tilt angle (α1) is at most 0.75 times, in particular at most 0.4 times, such as at most 0.2 times, in particular at most 0.25 times, the transmittance in the blue wavelength range (at least a part) at the second tilt angle (α2).

[0059] In an embodiment where the first optical element has a dichroic mirror, the reflectance in the blue wavelength range (at least a part thereof) at the first tilt angle (α1) is at most 0.5 times the reflectance in the blue wavelength range (at least a part thereof) at the second tilt angle (α2). That is, by tilting the first optical element to the first tilt angle (α1) with respect to the second tilt angle (α2), the reflectance of blue light can be reduced to one half. In a further embodiment, the reflectance in the blue wavelength range (at least a part thereof) at the first tilt angle (α1) is at most 0.75 times, particularly at most 0.4 times, such as at most 0.3 times, particularly at most 0.2 times the reflectance in the blue wavelength range (at least a part thereof) at the second tilt angle (α2). In an embodiment, the at least a part of the blue wavelength range may include, particularly, a range of 440 to 495 nm, particularly a range of 445 to 475 nm, such as a range of 440 to 480 nm.

[0060] In particular, the transmission (or reflection) of light in the green to yellow wavelength range and the red wavelength range by the first optical element may be substantially independent of the tilt angle (α). For example, in an embodiment, the dichroic filter may transmit at least 80%, particularly at least 95%, such as at least 97%, at least 90% of the second device light and the luminescence material light, regardless of the tilt angle (α).

[0061] In a further embodiment, the dichroic filter may have one or more of a dichroic longpass filter and a dichroic narrow-band notch filter, particularly a dichroic longpass filter, or particularly a dichroic narrow-band notch filter.

[0062] In an embodiment, the first optical element may be displaced (linearly) with respect to the optical axis of the first device light, etc. In particular, the control system is configured to control the displacement (d). In a further embodiment, the wavelength-dependent transmittance in the blue wavelength range may depend on the displacement (d). Accordingly, the control system may be configured to control the displacement (d), thereby controlling the transmittance (or reflectance) of light in the blue wavelength range, and thereby controlling the correlated color temperature of the system light.

[0063] In an embodiment, the control system may be configured to control the displacement (d) to move the first optical element between the first position (p1) and the second position (p2), particularly by controlling the actuator.

[0064] As described above, the control system may control the above-described actuator, and the actuator may control the displacement.

[0065] In particular, the transmission (or reflection) of light in the green-yellow wavelength range and the red wavelength range by the first optical element may be substantially independent of the tilt angle (α). For example, in an embodiment, the dichroic filter may transmit at least 80%, particularly at least 90%, such as at least 95% and up to 97% of the second device light and the luminescence material light, regardless of the tilt angle (α).

[0066] As described above, the light generation system may be configured to generate system light including one or more of the first device light, the second device light, and the luminescence material light. In particular, generally, the system light may include at least a portion of the first device light, at least a portion of the second device light, and at least a portion of the luminescence material light.

[0067] As described above, the light generation system may further include a control system. The control system may be configured to control, in particular, one or more of the first light generation device, the second light generation device, and the first optical element.

[0068] In an embodiment, the control system may be configured to control the spectral power distribution of the system light, particularly in the operating mode (of the light generation system). In particular, the control system may be configured to control the spectral power distribution by controlling (at least) the first optical element, particularly by controlling at least the tilt angle α of the first optical element. Accordingly, the control system may be configured to control the spectral power distribution of the system light by controlling the transmittance or reflectance of the first optical element in the blue wavelength range.

[0069] In a further embodiment, the control system may be configured to control the correlated color temperature of the system light to a value selected from a correlated color temperature range, such as in the range of 1800 to 6500 K, particularly in the operating mode (of the light generation system). The correlated color temperature range may have, in an embodiment, a range of 1800 to 6500 K. In a further embodiment, the correlated color temperature range may have a range of 2700 to 6500 K. In a further embodiment, the correlated color temperature range may have a range of 4000 to 5500 K.

[0070] In particular, in an embodiment, the correlated color temperature of the system light may be controllable over a CCT control range within a correlated color temperature range, such as in the range of 1800 to 6500 K. In a further embodiment, the CCT control range may be at least 250 K, such as at least 500 K, particularly at least 750 K, such as at least 1000 K. For example, when the CCT control range is 250 K, the control system can control the system light to have a first CCT and a second CCT, and the first CCT and the second CCT are 250 K apart. An example of a CCT control range of at least 250 K may be a CCT controllable between 2700 K and 2950 K, and a CCT control range of at least 1000 K may be a CCT controllable between 2700 K and 3700 K. In a further embodiment, the CCT control range may be at most 2500 K, such as at most 2000 K, particularly at most 1500 K.

[0071] In particular, the system light may have a CRI of at least 75, such as at least 80, particularly at least 85, over the CCT control range, that is, for (essentially) any value of CCT within the CCT control range, the CRI of the system light may be at least 70.

[0072] Similarly, in an embodiment, the system light may have an R9 of at least 20, such as at least 30, particularly at least 0, such as at least 10, over the CCT control range.

[0073] In an embodiment, the light generation system may further include a second optical element. In particular, the second optical element includes a collimator element. The second optical element may be configured particularly downstream of the luminescence material (and the first light generation device). In a further embodiment, the second optical element may be configured upstream of the first optical element. Accordingly, the second optical element may be configured to be in a light receiving relationship with the first light generation device and the luminescence material, and may be configured to supply collimated light, particularly collimated first device light and collimated luminescence material light, to the first optical element.

[0074] The light generation system may further include (other) optical systems (see also above). The term "optical system" may particularly refer to one or more (third) optical elements. The optical system may include one or more of mirrors, reflectors, collimators, lenses, prisms, diffusers, phase plates, polarizers, diffraction elements, diffraction gratings, dichroic ones, arrays of one or more of the foregoing, etc. Instead or in addition, the term "optical system" may refer to a holographic element or a mixing rod. In an embodiment, the optical system may include one or more of a beam expander optical system and a zoom lens optical system.

[0075] In an embodiment, the light generation system may further include a light mixing chamber. The light mixing chamber may be configured particularly downstream of the first light generation device. In particular, the light mixing chamber material may also be configured upstream of at least a part of the luminescence material. Accordingly, in an embodiment, the light mixing chamber may be configured between the first light generation device and the luminescence material, particularly along (or "within") the first device optical path. In particular, the light mixing chamber may be configured to be in a light receiving relationship with the first light generation device, and may be configured to supply (mixed) first device light to the luminescence material.

[0076] As used herein, the term "optical mixing chamber" may refer to an optical element, particularly an optical waveguide, or particularly an optical chamber, configured to mix light from a plurality of light sources so as to supply a (substantially) uniform spectrum in the far field. The optical chamber may have a light reflecting wall.

[0077] As described above, the control system may be configured to control the first light generation device. In particular, the control system may be configured to control the first device light supplied by the first light generation device by controlling the first light generation device, particularly in the operating mode (of the light generation system).

[0078] For example, in an embodiment, the first center wavelength (λ C1 ) of the first device light may depend on the temperature of the first light generation device. In such an embodiment, the control system may be configured to control the spectral power distribution of the system light by controlling the first center wavelength (λ C1 ) of the first device light, such as by controlling the temperature of the first light generation device.

[0079] In an embodiment, the first center wavelength (λ C1 ) of the first device light may be controlled by controlling the current passing through the first light generation device. In particular, the first light generation device has a solid state device.

[0080] The light generation system has a plurality of first light generation devices, and two or more of the first light generation devices are configured to generate first device light having different center wavelengths in the blue wavelength range. The control system is configured to control the spectral power distribution of the system light by controlling the radiation flux of the device light of the two or more first light generation devices. Similarly, in such an embodiment, the light mixing chamber may be configured to be in a light receiving relationship with the two or more first light generation devices, particularly the plurality of first light generation devices.

[0081] Similarly, in an embodiment, the control system may be configured to control the second light generation device. In particular, the control system may be configured to control the second device light supplied by the second light generation device by controlling the second light generation device, particularly in the operating mode (of the light generation system). For example, in an embodiment, the control system may be configured to control the light flux of the second device light by controlling the second light generation device, such as by controlling the output of the second light generation device.

[0082] In a further embodiment, the second center wavelength (λ C2 ) of the second device light may depend on the temperature of the second light generation device. In such an embodiment, the control system may be configured to control the spectral power distribution of the system light by controlling the second center wavelength (λ C2 ) of the second device light, such as by controlling the temperature of the second light generation device.

[0083] In an embodiment, the luminescent material may supply luminescent material light having a luminescent material light center wavelength λ CL . In particular, the luminescent material light center wavelength λ CL may be selected from a range of 520 to 590 nm, such as a range of 550 to 590 nm, a range of 545 to 590 nm, particularly a range of 560 to 580 nm.

[0084] In a further embodiment, the first center wavelength λ C1 may be selected from the range of 440 to 500 nm, such as the range of 440 to 490 nm, particularly the range of 440 to 480 nm, such as the range of 450 to 480 nm. In a further embodiment, the first center wavelength may be selected from the range of 440 to 470 nm, particularly the range of 445 to 465 nm. In a further embodiment, the first center wavelength may be selected from the group including 445 nm, 450 nm, 455 nm, and 465 nm. In a further embodiment, the first center wavelength may be 445 nm. In a further embodiment, the first center wavelength may be 450 nm. In a further embodiment, the first center wavelength may be 455 nm. In a further embodiment, the first center wavelength may be 465 nm.

[0085] Similarly, in an embodiment, the second center wavelength λ C2 may be selected from the range of 620 to 780 nm, such as the range of 620 to 650 nm, particularly the range of 630 to 650 nm. In a further embodiment, the second center wavelength may be selected from the range of 630 to 640 nm. In a further embodiment, the second center wavelength may be selected from the group including 630 nm, 632 nm, 634 nm, 636 nm, 638 nm, and 640 nm. In a further embodiment, the two center wavelengths may be 630 nm. In a further embodiment, the two center wavelengths may be 632 nm. In a further embodiment, the two center wavelengths may be 634 nm. In a further embodiment, the two center wavelengths may be 636 nm. In a further embodiment, the two center wavelengths may be 638 nm. In a further embodiment, the two center wavelengths may be 640 nm.

[0086] In particular, the first device light has a first center wavelength (λ C1has, and the second device light has a second centroid wavelength (λ C2 ) selected from the range of 620 to 650 nm, and the luminescent material light has a luminescent material light centroid wavelength (λ CL ) selected from the range of 560 to 580 nm, excellent results may be obtained in the embodiment.

[0087] To supply the system light, the second device light may be combined with the first device light and the luminescent material light.

[0088] Therefore, the control system may be configured to control the relative contributions of the first device light, the second device light, and the luminescent material light in the system light. In particular, the control system may adjust the color point of the system light so as to (substantially) change the CCT of the system light while remaining on the BBL by controlling the relative contributions of the first device light, the second device light, and the luminescent material light in the system light.

[0089] In an embodiment, the first device light and the second device light may be combined upstream of the luminescent material. Therefore, in an embodiment, the luminescent material may be transmissive, particularly transparent, or particularly translucent with respect to the second device light. In particular, in an embodiment, the luminescent material may be configured to be in a light-receiving relationship with the second light generating device. In particular, the second light generating device may be configured upstream of the luminescent material (and the first optical element).

[0090] The (red) second device light may pass through the luminescent material without being converted (or be reflected by the luminescent material), which may result in visible red speckles, which may be undesirable. Thus, in embodiments where the second light generating device is configured to supply (red) second device light to the luminescent material (see below), the second light generating device may comprise a superluminescent diode. Thereby, the (red) speckles may be removed.

[0091] In a further embodiment, the first device light and the second device light may be combined downstream of the luminescent material, i.e., the second device light may be combined with the first device light and the luminescent material.

[0092] In a further embodiment, the first device light and the second device light may be combined downstream of the first optical element.

[0093] In an embodiment, the light generation system may further include one or more beam combiners, particularly, a plurality of beam combiners. The beam combiner may be particularly configured to combine the first device light and the second device light. In particular, the beam combiner may be configured to combine the first device light, the luminescence material light, and the second device light. In an embodiment, the beam combiner may be selected from the group consisting of a surface scattering diffuser, a volume scattering diffuser, a holographic optical element, a light pipe, an optical guide, a Keller integrator optical system, a collimator, a dichroic beam combiner, a dichroic cube, a dichroic beam splitter, a diffraction grating, and a polarization beam splitter, and particularly, may be selected from the group consisting of a holographic optical element, a light pipe, a Keller integrator optical system, a collimator, a dichroic beam combiner, a dichroic cube, a dichroic beam splitter, a diffraction grating, and a polarization beam splitter. In a further embodiment, the beam combiner may particularly include a fiber bundle combiner, and particularly, the fiber bundle combiner may be configured to combine the first device light and the second device light.

[0094] In an embodiment, the beam combiner may be configured downstream of the first light generation device (with respect to the first device optical path) and downstream of the second light generation device (with respect to the second device optical path of the second device light). In a further embodiment, the beam combiner may be configured upstream of the luminescence material. Alternatively, in a further embodiment, the beam comb may be configured downstream of the luminescence material. Similarly, in an embodiment, the beam combiner may be configured upstream of the first optical element, while in a further embodiment, the beam combiner may be configured downstream of the first optical element.

[0095] The terms "upstream" and "downstream" relate to the arrangement of an item or feature with respect to the propagation of light from the light generating means (herein, in particular, the light source), such that, with respect to a first position within the light beam from the light generating means, a second position within the light beam closer to the light generating means is "upstream" and a third position within the light beam further away from the light generating means is "downstream".

[0096] The light generating system may be, for example, an office lighting system, a home application system, a store lighting system, a household lighting system, an accent lighting system, a spot lighting system, a theater lighting system, an optical fiber application system, a projection system, a self-lit display system, a pixelated display system, a segmented display system, a warning sign system, a medical lighting application system, an indicator sign system, a decorative lighting system, a portable system, an automotive application, an (outdoor) road lighting system, an urban lighting system, a greenhouse lighting system, horticultural lighting, digital projection, or part of an LCD backlight, or may be used therein. The light generating system (or the lighting fixture) may be, for example, part of an optical communication system or a disinfection system, or may be used therein.

[0097] In embodiments, the system light may have white light. Thus, in embodiments, the light generating system may be configured to generate white light, particularly with a variable CCT.

[0098] As used herein, the term "white light" and similar terms are known to those skilled in the art. The white light may relate to light having a correlated color temperature (CCT) in the range of, in particular, between about 2000K and 20000K, especially between 2700K and 20000K, between about 1800K and 20000K, and in the case of general illumination, especially in the range of 2700K to 6500K, in the range of about 2000K to 7000K. In embodiments, for example, in the case of backlight applications or other applications, the correlated color temperature (CCT) may be especially in the range of about 7000 to 20000K. Additionally, in embodiments, the correlated color temperature (CCT) is especially within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), especially within about 10 SDCM from the BBL, and even more especially within about 5 SDCM from the BBL.

[0099] In certain embodiments, the correlated color temperature (CCT) may be selected from the range of 6000K to 12000K, such as at least 8000K, so as to be selected from the range of 7000K to 12000K. Additionally, in embodiments, the correlated color temperature (CCT) may be selected from the range of 6000K to 12000K so as to be selected from the range of 7000K to 12000K, especially in combination with a CRI of at least 70.

[0100] 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. As used herein, UV may especially refer to wavelengths selected from the range of 190 to 380 nm, such as 200 to 380 nm. 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" may refer to UV radiation, visible light, and IR radiation. In certain embodiments, especially for lighting applications, the terms "light" and "radiation" refer to (at least) visible light.

[0101] The terms "violet light" or "violet emission" relate in particular to light having a wavelength in the range of about 380 to 440 nm. The terms "orange light" or "orange emission" relate in particular to light having a wavelength in the range of about 590 to 620 nm. The terms "pink light" or "pink emission" refer to light having a blue component and a red component. The term "cyan" may refer to one or more wavelengths selected from the range of about 490 to 520 nm. The term "amber" may refer to one or more wavelengths selected from the range of about 585 to 605 nm, such as about 590 to 600 nm. The phrase "light having one or more wavelengths within a wavelength range" and similar phrases may in particular indicate that the light (or radiation) shown has a spectral power distribution having at least one intensity at these one or more wavelengths within the wavelength range shown. For example, a blue-emitting solid-state light source has a spectral power distribution having an intensity at one or more wavelengths within the wavelength range of 440 to 495 nm.

[0102] The term "control" and similar terms refer, in particular, to determining at least 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, for example, measuring, displaying, actuating, opening, shifting, changing the temperature, etc., such as imposing behavior on the element (determining the behavior of the element or supervising the operation of the element). The term "control" and similar terms may further include monitoring. Thus, the term "control" and similar terms may include imposing behavior on an element, and may also include imposing behavior on an element and monitoring the element. The control of the element may be performed by a control system, which may sometimes be referred to as a "controller". Thus, the control system and the element may be functionally coupled, at least temporarily or permanently. The element may have the control system. In embodiments, the control system and the element may not be physically coupled. Control can be performed via wired and / or wireless control. The term "control system" may particularly refer to a plurality of different control systems that are functionally coupled, for example, one of the plurality of different control systems may be a master control system and one or more other control systems may be slave control systems. The control system may have a user interface or may be functionally coupled to a user interface.

[0103] The control system may also be configured to receive and execute instructions from a remote control device. In embodiments, the control system may be controlled via an application in a device such as a portable device such as a smartphone or iPhone, tablet, etc. Thus, the device is not necessarily coupled to the lighting system, but may be functionally coupled to the lighting system (temporarily).

[0104] Accordingly, in an embodiment, the control system may (also) be configured to be controlled by an application in a remote device. In such an embodiment, the control system of the lighting system may be a slave control system or may control in a slave mode. For example, the lighting system may be identifiable by a code, particularly 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 input by a user interface including an optical sensor (e.g., a QR code reader) for the (unique) code. The lighting system may also have means for communicating with other systems or devices based on Bluetooth, Thread, WIFI, LiFi, ZigBee, BLE or WiMAX, or another wireless technology, etc.

[0105] The system, or apparatus, or device may perform an operation in a certain "mode" or "operating mode" or "mode of operation" or "operable mode". The term "operating mode" may also be referred to as "control mode". Similarly, in a method, an operation, or a stage, or a step may be performed in a certain "mode" or "operating mode" or "mode of operation" or "operable mode". This does not exclude the possibility that the system, or apparatus, or device may be adapted to provide another control mode, or a plurality of other control modes. Similarly, this may not exclude the possibility that one or more other modes may be performed before and / or after performing the mode.

[0106] However, in an embodiment, a control system adapted to provide at least the control mode may be available. If other modes are available, the selection of such a mode may be performed, in particular, via a user interface, but other options may also be possible, such as performing the mode depending on a sensor signal or a (time) scheme. The operating mode may, in an embodiment, refer to a system, or an apparatus, or a device that can operate only in a single operating mode (i.e., "on" without further adjustability).

[0107] Accordingly, in an embodiment, the control system may control depending on one or more of an input signal of a user interface, a sensor signal (of a sensor), and a timer. The term "timer" may refer to a clock and / or a predetermined time scheme.

[0108] In still other aspects, the present invention also provides a lamp or a lighting fixture having a light generation system as defined herein. The lighting fixture may further include a housing, optical elements, louvers, and the like. The lamp or the lighting fixture may further include a housing surrounding the light generation system. The lamp or the lighting fixture may have a light window or a housing opening in the housing, and the system light may escape from the housing through the light window or the housing opening. In still other aspects, the present invention also provides a projection device having a light generation system as defined herein. In particular, the projection device or "projector" or "image projector" may be an optical device that projects an image (or video) onto a surface such as a projection screen. The projection device may include one or more light generation systems as described herein. Accordingly, in one aspect, the present invention provides a light generation device selected from the group of a lamp, a lighting fixture, a projector device, a disinfection device, a photochemical reaction device, and a free space optical communication device, the light generation device having a light generation system as defined herein. The light generation device may have a housing configured to accommodate or a carrier configured to support one or more elements of the light generation system. For example, in an embodiment, the light generation device may have a housing configured to accommodate or a carrier configured to support one or more of the first light generation device, the second light generation device, the luminescence material, and the first optical element.

[0109] The terms "lighting device" or "lighting system" and similar terms may be replaced by the terms "light generation device" or "light generation system" (and similar terms). The lighting device or lighting system may be configured to generate device light (or "lighting device light") or system light (or "lighting system light"). As described above, the terms light and radiation may be used interchangeably.

[0110] The lighting system may have a light source. In an embodiment, the system light may have one or more of light source light and converted light source light (such as luminescence material light).

[0111] The term "UV radiation" may refer to near-UV radiation (NUV) in certain embodiments. Therefore, in this specification, the term "(N)UV" is also used to generally refer to UV and to refer to NUV in certain embodiments. The term "IR radiation" may refer to near-IR radiation (NIR) in certain embodiments. Therefore, in this specification, the term "(N)IR" is also used to generally refer to IR and to refer to NIR in certain embodiments. In this specification, IR (infrared) may particularly refer to radiation having a wavelength selected from the range of 780 to 3000 nm, such as from 780 to 2000 nm, for example, a wavelength of at least 900 nm, up to about 1500 nm, although in certain embodiments, other wavelengths may also be possible. Thus, the term IR may, in this specification, refer to one or more of near-infrared (NIR (or IR-A)) and short-wavelength infrared (SWIR (or IR-B)), particularly NIR.

[0112] The term "center wavelength", also denoted as λc, is known in the art and refers to the wavelength value at which half of the optical energy is at a shorter wavelength and half of the optical energy is at a longer wavelength, and the value is expressed in nanometers (nm). It is the wavelength that divides the integral of the spectral power distribution, as represented by the formula λc = Σλ × I(λ) / (ΣI(λ)), into two equal parts, 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 integral intensity). The center wavelength may be determined, for example, in an operating state. BRIEF DESCRIPTION OF THE DRAWINGS

[0113] Here, as an example only, embodiments of the present invention will be described with reference to the accompanying schematic drawings in which corresponding reference numerals indicate corresponding parts.

Figure 1A

Figure 1B

Figure 1C

Figure 2A

Figure 2B

Figure 2C

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 4

[0114] The schematic drawings are not necessarily to scale.

Embodiments for Carrying Out the Invention

[0115] Figures 1A to 1C schematically illustrate embodiments of the light generation system of the present invention. In the illustrated embodiments, the light generation system 1000 includes a first light generation device 110, a second light generation device 120, a luminescence material 200, and a first optical element 410. In the illustrated embodiments, the first light generation device 110 is configured to generate blue first device light 111, and the second light generation device 120 is configured to generate red second device light 121. In particular, both the first light generation device 110 and the second light generation device 120 may each have one or more of a laser diode and a superluminescent diode. The luminescence material 200 is configured to convert at least a part of the first device light 111 into luminescence material light 201, and is thus configured downstream of the first light generation device 110. The luminescence material light 201 may have one or more wavelengths within the green to yellow wavelength range. Accordingly, the light generation system 1000 may be configured to generate system light 1001 including one or more of the first device light 111, the second device light 121, and the luminescence material light 201. The first device light 111 has blue light, the second device light 121 has red light, and the luminescence material light 201 has green to yellow light. Thereby, the system light 1001 may have an appropriate mixture of colors for a high CRI such as CRI≧80. In the illustrated embodiments, the first optical element 410 is configured to be in a light receiving relationship with the first light generation device 110 and the luminescence material 200. In particular, the first optical element 410 may have a controllable wavelength-dependent transmittance and / or reflectance in the blue wavelength range. For example, in the illustrated embodiments, the first optical element 410 has a dichroic filter 415, and the dichroic filter 415 is movable with respect to the optical axis O of the first device light 111, such as tiltable (Figs. 1A to 1B) or displaceable (Fig. 1C). In particular, the wavelength-dependent transmittance in the blue wavelength range depends on a position p such as a tilt angle α.As schematically illustrated in FIGS. 1A to 1B, the tilt angle α may in particular be the angle between (i) the plane defined by the first optical element 410 and (ii) the optical axis O of the first device light 111 (when the first device light 111 reaches the first optical element 410). In particular, in the illustrated embodiment, the light generation system has an actuator 430 configured to move the first optical element 410. In such an embodiment, the control system 300 may in particular be configured to control the actuator 430. Accordingly, the amount of blue light in the system light can be adjusted via the first optical element 410, whereby the CCT of the system light can be adjusted. In particular, in an embodiment, the control system 300 may be configured to control the tilt angle α. In a further embodiment, the control system 300 may be configured to control the spectral power distribution of the system light 1001 by controlling at least the wavelength-dependent transmittance (or wavelength-dependent reflectance) of the first optical element 410, particularly in the operating mode of the light generation system 1000. In a further embodiment, the control system 300 may be configured to control the correlated color temperature of the system light 1001 to a value selected from the range of 1800 to 6500 K, particularly in the operating mode of the light generation system 1000. In particular, the correlated color temperature of the system light 1001 is controllable over at least a CCT control range of at least 250 K within the range of 1800 to 6500 K.

[0116] In the illustrated embodiment, the luminescence material operates in transmission mode. In a further embodiment, the luminescence material may operate in reflection mode.

[0117] In a further embodiment, the dichroic filter 415 may have one or more of linear filters such as a dichroic long-pass filter, a dichroic (narrowband) notch filter, and a linear variable filter (LVF), particularly a dichroic long-pass filter, or particularly a dichroic narrowband notch filter, or particularly a linear variable filter.

[0118] FIG. 1A schematically illustrates an embodiment in which the light generation system 1000 further includes a second optical element 420 having a collimator element. In particular, in the illustrated embodiment, the second optical element 420 is configured downstream of the luminescence material 200 and the first light generation device 110 and upstream of the first optical element 410.

[0119] FIG. 1B schematically illustrates an embodiment in which the light generation system 1000 further includes a light mixing chamber 450 configured downstream of the first light generation device 110 and upstream of at least a portion of the luminescence material 200.

[0120] In the illustrated embodiment, the luminescence material 200 is configured downstream of the second light generation device 120, particularly in a light receiving relationship with the second light generation device 120. Thus, in the illustrated embodiment, the luminescence material 200 may be transmissive to the second device light 121. In particular, in the illustrated embodiment, the light generation system 1000 further includes a beam combiner 470 configured to combine the first device light 111 and the second device light 121. In particular, the beam combiner 470 may include a fiber bundle combiner 460 configured to combine the first device light 111 and the second device light 121. In a further embodiment, the beam combiner 470 may include a dichroic element configured to combine the first device light 111 and the second device light 121.

[0121] In particular, in the illustrated embodiment, the mixed light of blue laser light and red laser light is incident on the optical mixing chamber at 450. In the optical mixing chamber at 450, the luminescence material 200 is excited by the blue laser light, and the red laser light is transmitted and partially scattered. The converted white light is collected and collimated by a second optical element 420 such as a compound parabolic concentrator (CPC) that can be attached to the luminescence material 200. In the illustrated embodiment, the (pre-collimated) beam passes through a dichroic long-pass filter, and in the dichroic long-pass filter, a part of the blue transmitted light can be removed by applying it to the filter according to the angular direction of the filter and the desired spectral composition. Finally, the resulting white beam may be further collimated by a lens or the like.

[0122] FIG. 1C schematically illustrates an embodiment in which the light generation system 1000 has a plurality of first light generation devices 110 and further has a beam combiner configured to combine the first device light 111 of the plurality of first light generation devices 110. In such an embodiment, in particular, two or more first light generation devices 110 may be configured to generate first device light 111 having different center wavelengths in the blue wavelength range. Further, in such an embodiment, the control system 300 may be configured to control the spectral power distribution of the system light 1001 by controlling the radiation flux of the device light 111 of two or more first light generation devices 110.

[0123] Therefore, in an embodiment, the light generation system 1000 may include (a) first beam combiners 470, 471 configured to combine the first device light 111 of a plurality of first light generation devices, and (b) second beam combiners 470, 472 configured to combine the first device light 111 and the second device light 121.

[0124] In a further embodiment, the beam combiner 470, particularly the first beam combiner 470, 471, or particularly the second beam combiner 470, 472 may be selected from the group of a surface scattering diffuser, a volume scattering diffuser, a holographic optical element, a light pipe, an optical waveguide, a Keller integrator optical system, a collimator, a dichroic beam combiner, a dichroic cube, a dichroic beam splitter, and a polarization beam splitter.

[0125] FIG. 1C further schematically illustrates a displacement d of the first optical element 410, at which displacement d the first optical element 410 can be moved between a first position p1 and a second position p2. In particular, in an embodiment, the wavelength-dependent transmittance (or reflectance) in the blue wavelength range may be different between the first position p1 and the second position p2. For example, in an embodiment, the first optical element 410 may have a patterned linear filter in which the optical density of transmitted blue light varies over the length of the filter, and an adjustment function is obtained by a linear shift of the filter.

[0126] FIG. 2A schematically illustrates the spectrum of the first device light 111. FIG. 2A further schematically illustrates the wavelength-dependent transmittance of an embodiment of the first optical element 410, with transmittance (in % units) versus wavelength λ (in nm units). In particular, in the illustrated embodiment, the transmittance depends on the angles of incidence of 0°, 10°, and 20° in the first optical element 410, i.e., the tilt angles α of approximately 90°, 80°, and 70°. Thus, for a particular embodiment, the first device light 111 can be mostly transmitted at an angle of incidence of 20°, such as an angle of incidence of 30°, whereas the first device light 111 can be mostly blocked at an angle of incidence of 10°. However, even at an angle of incidence of 0°, the second device light 121 and the luminescence material light 201 may be essentially completely transmitted, i.e., at least 90%, such as at least 93%, of the second device light 121 and the luminescence material light 201 may pass through the first optical element regardless of the tilt angle α.

[0127] In particular, FIG. 2A schematically illustrates that the change in the blue laser content in the system light 1001 can be achieved using the first optical element 410. Specifically, FIG. 2A shows that the transmittance of the dichroic long-pass filter can be changed according to the incident angle of the incident light, and the transmission edge of the filter shifts toward a shorter wavelength as the incident angle increases. By setting the edge of the filter at normal incidence near the excitation laser wavelength and changing the angle of the filter with respect to the optical axis of light propagation, it is theoretically possible to adjust the amount of blue light in the resulting spectrum in the range from 0% to 95% with respect to the initial intensity.

[0128] FIG. 2B schematically illustrates the spectral power distribution of the system light 1001 in terms of intensity I (in a.u.) versus wavelength λ (in nm), together with the display of the first centroid wavelength λ C1 of the first device light 111, the second centroid wavelength λ C2 of the second device light 121, and the luminescence material light centroid wavelength λ CL of the luminescence material light 201. In particular, in the illustrated embodiment, the first device light 111 has a first centroid wavelength λ C1 selected from the range of 440 to 480 nm, the second device light 121 has a second centroid wavelength λ C2 selected from the range of 620 to 650 nm, and the luminescence material light 201 has a luminescence material light centroid wavelength λ CL selected from the range of 520 to 590 nm, such as in the range of 550 to 590 nm.

[0129] In particular, FIG. 2B schematically illustrates the results of spectral simulations using the actually available blue and red laser wavelengths and a Gd-doped YAG ceramic phosphor. Depending on the blue content in the spectrum, it is possible to cover a wide CCT range of 2700 to 6500 K, and the intensity of the red laser is adjusted to yield a color point on the BBL. The red laser wavelength of 638 nm is chosen because of the actual availability of relatively inexpensive high-power lasers (>5 W) for this wavelength range >637 nm. 465 nm for blue is selected as the longest blue wavelength of commercially available laser diodes. Shorter blue wavelengths may be more advantageous due to higher absorption by the YAG phosphor. However, (relatively) long blue wavelengths may also have a beneficial effect on the CRI.

[0130] FIG. 2C schematically illustrates the spectral power distribution of system light 1001 supplied by an embodiment of a light generation system 1001, in which the light generation system 1000 has at least two first light generation devices 110 and the first optical element 410 has a long pass filter, in particular a long pass filter with an edge position controllable, for example, by controlling the angle α (see above). In particular, in the illustrated embodiment, one of the at least two first light generation devices 110 is configured to supply first device light 111 having a center wavelength at about 455 nm for more efficient excitation of the luminescent material, while the other of the at least two first light generation devices 110 is configured to supply first device light 111 having a center wavelength at about 465 nm to contribute to the improvement of the CRI. In this case, the application of the long pass filter can be controlled to set the end position to ~460 nm or more so as to set the total amount of transmitted blue light for the initial color point. The adjustability of the color point can further be affected by electronically adjusting the amount of laser output from two separate blue laser channels. Thus, in the illustrated embodiment, one of the at least two first light generation devices 110 can supply first device light 111 that is partially converted into luminescent material light 201, while the remaining portion of the first device light 111 is blocked by the long pass filter, whereas the first device light 111 supplied by the other of the at least two first light generation devices 110 is essentially not converted by the luminescent material 200 and can mostly pass through the long pass filter. Thereby, the amount of blue light in the system light 1001 can be controlled by controlling the other of the at least two first light generation devices 110.

[0131] In a further embodiment, instead of a long pass filter, a narrow band notch filter with band suppression at or near 465 nm can also be used. In such an embodiment, the change in the suppression band and transmittance can also be controlled as a function of the angle of incidence.

[0132] Furthermore, by using the effect of the wavelength shift of the emission wavelength of the laser diode as a function of temperature, color point adjustment without mechanical adjustment can also be achieved. A typical value of the wavelength shift is ~1 nm / 10 °C, and the emission shifts to longer wavelengths with increasing temperature. By having a filter with a sharp transition edge and adjusting the temperature of the laser diode (e.g., with a heating element), it is possible to adjust the amount of transmitted blue laser light through the dichroic filter over a wide range. Thus, in an embodiment, the center wavelength λ C1 of the first device light 111 may depend on the temperature of the first light generation device 110, and the control system 300 is configured to control the spectral power distribution of the system light 1001 by controlling the center wavelength λ C1 of the first device light 111, in particular by controlling the temperature of the first light generation device 110.

[0133] Similarly, pulse width modulation (PWM) may be used to effectively control the temperature of the light generation device, in particular its junction temperature, in order to shift the center wavelength, in particular while (essentially) maintaining the average optical beam. Thus, in an embodiment, the control system 300 may be configured to control the spectral power distribution of the system light 1001 by controlling the center wavelength λ C1 of the first device light 111 by controlling the pulse frequency of the first light generation device 110.

[0134] Figures 3A through 3D schematically illustrate how the CRI and R9 values of the system light 1001 can vary depending on the (center) wavelength of the (blue) first device light 111 in an embodiment. The longest wavelengths in the investigated actual range may be preferred for providing a high CRI over a wide CCT range. For example, for a center wavelength of about 465 nm, a CRI of 90 can be achieved for CCTs in the range of about 4000 K to about 5500 K.

[0135] In particular, FIG. 3A schematically shows the relative intensity I with respect to the wavelength λ (in nm) of a blue light source having a center wavelength at 457, 460, 463, and 465 nm.

[0136] FIG. 3B schematically shows the CRI with respect to the CCT (in K units) of a blue light source having a center wavelength at 457, 460, 463, and 465 nm, or a combination of two blue light sources having center wavelengths at 457 and 465 nm. Accordingly, depending on the selected center wavelength of the first device light 111, a high CRI, such as about 80, in particular greater than 85, or even greater than 90, can be obtained over a wide CCT control range.

[0137] Accordingly, in an embodiment, the first device light may have a first center wavelength λ of at least 457, such as at least 460, in particular at least 463, such as at least 465. C1 may have.

[0138] In a further embodiment, the CCT control range may have at least 500K, such as at least 1000K, in particular at least 1500K, within a range of 1800 to 6500K, such as within a range of 2700 to 6500K.

[0139] FIG. 3C schematically shows the intensity (in a.u. units) with respect to the CCT (in K units) of a blue light source having a center wavelength at 457, 460, 463, and 465 nm, or a combination of two blue light sources having center wavelengths at 457 and 465 nm.

[0140] FIG. 3D schematically shows R9 with respect to the CCT (in K units) of a blue light source having a center wavelength at 457, 460, 463, and 465 nm, or a combination of two blue light sources having center wavelengths at 457 and 465 nm.

[0141] FIG. 4 schematically illustrates an embodiment of the lighting fixture 2 including the light generation system 1000 as described above. Reference numeral 301 indicates a user interface that can be functionally coupled to a control system 300 included in or functionally coupled to the light generation system 1000. FIG. 3 also schematically illustrates an embodiment of the lamp 1 having the light generation system 1000. Reference numeral 3 indicates a projector device or a projector system that can be used to project an image onto a wall or the like, and the projector device or the projector system may also include the light generation system 1000. Accordingly, FIG. 3 schematically illustrates an embodiment of the lighting device 1200 selected from the group of the lamp 1, the lighting fixture 2, the projector device 3, the disinfection device, the photochemical reaction device, and the optical wireless communication device, the lighting device 1200 having the light generation system 1000 as described herein. In an embodiment, such a lighting device can be the lamp 1, the lighting fixture 2, the projector device 3, the disinfection device, the photochemical reaction device, or the optical wireless communication device. The lighting device light escaping from the lighting device 1200 is indicated by reference numeral 1201. The lighting device light 1201 may essentially consist of the system light 1001, and thus, in a particular embodiment, may be the system light 1001. Reference numeral 1300 refers to a space such as a room. Reference numeral 1305 refers to the floor, reference numeral 1310 refers to the ceiling, and reference numeral 1307 refers to the wall.

[0142] The term "plurality" refers to two or more.

[0143] The terms "substantially" or "essentially" in this specification, and similar terms, will be understood by those skilled in the art. The terms "substantially" or "essentially" may include embodiments with "wholly", "completely", "entirely", etc. Thus, in embodiments, the adjectives "substantially" or "essentially" may be removed. Where applicable, the term "substantially" or "essentially" may relate to 90% or more, including 100%, 95% or more, particularly 99% or more, and even more particularly 99.5% or more.

[0144] The term "comprising" includes embodiments where the term "comprising" means "consisting of".

[0145] The term "and / or" relates particularly to one or more of the items mentioned before and after "and / or". For example, the phrase "item 1 and / or item 2", and similar phrases, may relate to one or more of item 1 and item 2. The term "comprising" may, in certain embodiments, refer to "consisting of", but in other embodiments may also refer to "including at least the specified species and optionally one or more other species".

[0146] Furthermore, terms such as first, second, third, etc. in the specification and claims are used to distinguish similar elements and are not necessarily used to describe a sequential or temporal order. Such terms are interchangeable under appropriate circumstances, and it should be understood that the embodiments of the invention described herein can operate in an order other than the order described or illustrated herein.

[0147] In this specification, among other things, a device, apparatus, or system in operation may be described. As will be apparent to those skilled in the art, the present invention is not limited to a method of operation or a device, apparatus, or system in operation.

[0148] The above embodiments do not limit the present invention but explain it. It should be noted that those skilled in the art will be able to design many other embodiments without departing from the scope of the appended claims.

[0149] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0150] The use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those recited in the claims. Throughout the specification and claims, unless the context clearly requires otherwise, words such as "comprise" shall be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, i.e., in the sense of "including, but not limited to".

[0151] The singular form of an element does not exclude the presence of a plurality of such elements.

[0152] The present invention may be implemented by hardware having several distinct elements, or by a suitably programmed computer. In device claims, apparatus claims, or system claims listing several means, some of these means may be implemented by exactly the same item of hardware. Merely the fact that a particular means is recited in mutually different dependent claims does not indicate that a combination of these means cannot be used advantageously. (Thus,) in yet another aspect, the present invention provides software which, when executed on a computer, is capable of realizing a method (one or more embodiments thereof) as described herein.

[0153] The present invention also provides a control system that can control a device, apparatus, or system, or execute a method or process described herein. Additionally, the present invention provides a computer program product that controls one or more controllable elements of such a device, apparatus, or system when executed on a computer that is functionally coupled to or included in the device, apparatus, or system.

[0154] The present invention further applies to a device, apparatus, or system having one or more of the characterizing features described in the specification and / or shown in the accompanying drawings. The present invention further relates to a method or process having one or more of the characterizing features described in the specification and / or shown in the accompanying drawings.

[0155] The various aspects described in this patent can be combined to provide further advantages. Further, those skilled in the art will understand that embodiments can be combined, and that three or more embodiments can also be combined. Additionally, some of the features can form the basis for one or more divisional applications.

Claims

1. A light generation system having a first light generation device, a second light generation device, a luminescence material, a first optical element, and a control system, wherein the first light generation device is configured to generate first device light of blue color, the first light generation device has one or more of a laser diode and a superluminescent diode, the second light generation device is configured to generate second device light of red color, the second light generation device has one or more of a laser diode and a superluminescent diode, wherein the luminescence material is configured downstream of the first light generation device, and the luminescence material is configured to convert at least a part of the first device light into luminescence material light having one or more wavelengths within a green to yellow wavelength range, wherein the first optical element is configured to be in a light receiving relationship with the first light generation device and the luminescence material, (i) the first optical element has a controllable wavelength-dependent transmittance in the blue wavelength range, and / or (ii) the first optical element has a controllable wavelength-dependent reflectance in the blue wavelength range, wherein the light generation system is configured to generate system light including one or more of the first device light, the second device light, and the luminescence material light, wherein the control system is configured to control the spectral power distribution of the system light by controlling the first optical element, the control system is configured to control the correlated color temperature of the system light to a value selected from the range of 1800 to 6500 K, and the correlated color temperature of the system light is controllable over a CCT control range of at least 250 K within the range of 1800 to 6500 K, wherein the light generation system further has a plurality of first light generation devices, two or more of the first light generation devices are configured to generate first device light having different center wavelengths in the blue wavelength range, and the control system is further configured to control the spectral power distribution of the system light by controlling the emission fluxes of the device lights of the two or more first light generation devices. A light generation system.

2. The first optical element has a dichroic filter, the dichroic filter is movable with respect to the optical axis of the first device light, the control system is configured to control the position of the dichroic filter, and (i) the wavelength-dependent transmittance in the blue wavelength range depends on the position, or (ii) the wavelength-dependent reflectance in the blue wavelength range depends on the position. The light generation system according to claim 1.

3. The light generation system according to claim 2, wherein the dichroic filter has one or more of a dichroic long-pass filter, a dichroic narrow-band notch filter, and a linear variable filter.

4. The dichroic filter is tiltable with respect to the optical axis, the control system is configured to control the tilt angle of the dichroic filter, and (i) the wavelength-dependent transmittance in the blue wavelength range depends on the tilt angle, or (ii) the wavelength-dependent reflectance in the blue wavelength range depends on the tilt angle. The light generation system according to claim 2.

5. The light generation system according to any one of claims 1 to 2, further comprising a second optical element, the second optical element having a collimator element, the second optical element being configured (a) downstream of the luminescence material and the first light generation device and (b) upstream of the first optical element, and the luminescence material being operated in a transmission mode.

6. The light generation system according to any one of claims 1 to 2, further comprising a light mixing chamber configured downstream of the first light generation device and upstream of at least a part of the luminescence material.

7. The first centroid wavelength of the first device light depends on the temperature of the first light generation device, and the control system is configured to control the spectral power distribution of the system light by controlling the first centroid wavelength of the first device light. The light generation system according to any one of claims 1 to 2.

8. The different centroid wavelengths in the blue wavelength range have a centroid wavelength selected from the range of 445 to 465 nm and a centroid wavelength selected from the range of 450 to 480 nm. The light generation system according to any one of claims 1 to 2.

9. wherein the luminescence material contains A ３ B ５ O １２ : a Ce-type luminescence material, wherein A contains one or more of Y, La, Gd, Tb, and Lu, and B contains one or more of Al, Ga, In, and Sc. The light generation system according to any one of claims 1 to 2.

10. The light generation system according to claim 9, wherein A contains one or more of Gd and Lu, and B contains at least 90 at.% of Al.

11. The light generation system according to any one of claims 1 to 2, wherein the luminescence material is transparent or translucent to the second device light, and the luminescence material is configured to be in a light receiving relationship with the second light generation device.

12. The light generation system according to claim 11, further comprising a beam combiner configured to combine the first device light and the second device light, the beam combiner being selected from the group consisting of a holographic optical element, a light pipe, a Keller integrator optical system, a collimator, a dichroic beam combiner, a dichroic cube, a dichroic beam splitter, a diffraction grating, a polarization beam splitter, and a fiber bundle combiner.

13. The light generation system according to any one of claims 1 to 2, wherein the CCT control range includes at least a range of 500 K within the range of 1800 to 6500 K.

14. The light generation system according to any one of claims 1 to 2, wherein the first device light has a first centroid wavelength selected from the range of 440 to 490 nm, the second device light has a second centroid wavelength selected from the range of 620 to 650 nm, and the luminescence material light has a luminescence material light centroid wavelength selected from the range of 560 to 580 nm.

15. An illumination device selected from the group consisting of a lamp, a lighting fixture, a projector device, a disinfection device, a photochemical reaction device, and an optical wireless communication device, the illumination device having the light generation system according to any one of claims 1 to 2.

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