Phosphor converted LED light source including UV LED taking into account excitation spectrum of phosphor

Abstract

The invention provides a light generating system (1000) comprising (a) a plurality of sets (150) of light generating devices (100) and (b) a luminescent material (200) wherein the light generating devices (100) are configured in an array (40); wherein the light generating device (100) is configured to generate device light (101); wherein the light generating device (100) comprises a solid state light source; wherein the plurality of sets (150) of light-generating devices (100) comprise at least three sets (50) of light-generating devices (100) wherein the light-generating devices (100) in different sets differ from one another at peak wavelengths of the device light (101), wherein the first set of first light-generating devices (110) is configured to provide first device light (111) having a first peak wavelength ([lambda] 1) in a visible wavelength range, in particular a blue wavelength range, a second set of second light generating devices (120) configured to generate second device light (121) having a second peak wavelength ([lambda] 2) in the UV wavelength range or in the purple wavelength range, and a third set of third light generating devices (130) configured to generate third device light (131) having a third peak wavelength ([lambda] 3) in the UV wavelength range or in the purple wavelength range; wherein the luminescent material (200) is arranged downstream of the array (40) of light generating devices (100); wherein the luminescent material (200) is configured to convert at least a portion of the first device light (101) into luminescent material light (201); and wherein the luminescent material (200) is configured to convert at least a portion of the second device light and / or at least a portion of the third device light (101) into luminescent material light (201); wherein the luminescent material (200) has different excitation intensities at different peak wavelengths ([lambda] 1, [lambda] 2, [lambda] 3); wherein the light generating devices (100) in at least three sets (50) are configured for different excitation intensities at different peak wavelengths according to an increase or decrease in the excitation intensity of the luminescent material (200).

Description

Technical Field

[0001] The invention relates to a system for generating light. The invention also relates to a lighting device. Background Art

[0002] Wavelength conversion lighting systems are known in the art. For example, US20190139943A1 describes a lighting device having a first group of at least one first solid-state emitter, each of which includes a first light emitting diode ("LED"), which, when excited, emits light having a peak wavelength in a range between about 440 nm and about 475 nm, and a second group of at least one second solid-state emitter, each of which includes a second LED, which, when excited, emits light having a peak wavelength in a range between about 390 nm and about 415 nm.

[0003] US11006493B discloses a lighting system that combines UV-A and white light with an adjustable CCT value, thereby mitigating any adverse effects from UV-A radiation. The device tunably adjusts the output of non-UV LEDs to produce an overall mixed output that meets the target CCT value.

[0004] WO2017 / 131715A1 discloses a device for generating tunable white light with controllable circadian energy performance. Multiple LED strings generate light with color points falling within the blue, yellow / green, red and cyan ranges, each LED string being driven by a separately controllable drive current to tune the generated light output. Different light emission modes using different combinations of multiple LED strings can be selected to tune the generated white light. One or more LED strings can have ultraviolet or violet LEDs. Summary of the invention

[0005] Although white LED sources can deliver, for example, up to about 300 lm / mm 2 intensity; static phosphor-converted laser white light sources can even give up to about 20.000lm / mm 2intensity. Cerium-doped garnets (such as YAG, LuAG) may be the most suitable luminescent converters, which can be pumped with blue lasers because the garnet matrix has a very high chemical stability. In addition, at low Ce concentrations (e.g., below 0.5%), temperature quenching may only occur above about 200°C. In addition, the emission from Ce has a very fast decay time, so optical saturation can be essentially avoided. Assuming, for example, reflection mode operation, a blue laser can be incident on the phosphor. In an embodiment, this can achieve an almost complete conversion of blue light, resulting in the emission of converted light. It is for this reason that it is recommended to use garnet phosphors with relatively high stability and thermal conductivity. However, other phosphors can also be applied.

[0006] UV light has been used for disinfection for more than 100 years. Wavelengths between about 190 nm and 300 nm can be strongly absorbed by nucleic acids, which can cause defects in the genome of an organism. This can be desirable for inactivating (killing) bacteria and viruses, but can also have undesirable side effects in humans. Therefore, in environments where people can live, such as offices, public transport, cinemas, restaurants, shops, etc., the choice of radiation wavelength, radiation intensity and radiation duration may be limited, thereby limiting the disinfection capabilities. Especially in such environments, additional disinfection measures can be beneficial to prevent the spread of bacteria and viruses, such as influenza or novel (coronavirus) viruses such as COVID-19, SARS and MERS.

[0007] It would seem desirable to produce systems that could provide alternative methods of air treatment, such as disinfection. Furthermore, existing disinfection systems may not be easily implemented in existing infrastructure, such as in existing buildings such as offices, hotel areas, and / or may not easily serve larger spaces. This may again increase the risk of contamination. Furthermore, incorporation into an HVAC system may not produce the desired effect and appears to be relatively complex. Furthermore, existing systems may not be efficient, or may be relatively bulky, or may not be easily incorporated into functional equipment such as lamps.

[0008] Therefore, one aspect of the present invention is to provide an alternative phosphor-converted LED light source, which preferably further at least partially obviates one or more of the above disadvantages.An object of the present invention may be to overcome or mitigate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0009] According to a first aspect, the present invention provides a light generating system. In an embodiment, the light generating system includes (a) multiple sets of light generating devices and (b) luminescent materials configured to generate visible light. In particular, the light generating devices can be configured in an array. In addition, in an embodiment, the light generating devices can be configured to generate device light. In particular, the light generating devices can include solid-state light sources. In an embodiment, the multiple sets of light generating devices can include at least two sets of light generating devices, more particularly at least three sets. In particular, the light generating devices in different sets can be different from each other in the peak wavelength of the device light. In an embodiment, a first set of a first light generating device can be configured to provide a first device light having a first peak wavelength (λ1) in a visible wavelength range, particularly in a blue wavelength range of 440nm-495nm. In addition, in an embodiment, a second set of a second light generating device can be configured to generate a second device light having a second peak wavelength (λ2) in a UV wavelength range or in a violet wavelength range of 380nm-440nm. In addition, in an embodiment, a third set of optional third light generating devices may be configured to generate a third device light having a third peak wavelength (λ3) in the UV wavelength range or in the violet wavelength range 380nm-440nm. In an embodiment, the luminescent material may be configured downstream of the array of light generating devices. In particular, the luminescent material may be configured to convert at least a portion of the first device light into luminescent material light. More specifically, the luminescent material may be configured to convert at least a portion of the second device light and / or at least a portion of the third device light into luminescent material light. In addition, in an embodiment, the luminescent material may have different excitation intensities at different peak wavelengths (λ1, λ2, λ3). In an embodiment, the light generating devices in at least two sets, more particularly at least three sets, may be configured for different excitation intensities at different peak wavelengths according to an increase or decrease in the excitation intensity of the luminescent material. The light generating device and the luminescent material are configured so that at least a portion of the second device light and / or at least a portion of the third device light is transmitted by the luminescent material.Thus, in a particular embodiment, the present invention may provide a light generating system comprising (a) a plurality of sets of light generating devices and (b) a luminescent material, wherein the light generating devices are configured in an array; wherein the light generating devices are configured to generate device light; wherein the light generating devices include a solid-state light source; wherein the plurality of sets of light generating devices include at least three sets of light generating devices, wherein the light generating devices in different sets differ from each other in the peak wavelength of the device light, wherein a first set of first light generating devices is configured to provide a first device light having a first peak wavelength (λ1) in a blue wavelength range, and a second set of second light generating devices is configured to generate a second device light having a second peak wavelength (λ2) in a UV wavelength range or in a violet wavelength range. Device light, a third set of third light generating devices is configured to generate a third device light having a third peak wavelength (λ3) in the UV wavelength range or in the violet wavelength range; wherein the luminescent material is configured downstream of the array of light generating devices; wherein the luminescent material is configured to convert at least a portion of the first device light into luminescent material light, and wherein in a specific embodiment, the luminescent material is configured to convert at least a portion of the second device light and / or at least a portion of the third device light into luminescent material light; wherein the luminescent material has different excitation intensities at different peak wavelengths (λ1, λ2, λ3); wherein the light generating devices in at least three sets are configured in an array according to an increase or decrease in the excitation intensity of the luminescent material for different excitation intensities at different peak wavelengths. Therefore, the present invention can provide a phosphor-converted LED light source, such as an LED filament or a COB including a UV LED, while in an embodiment, the excitation spectrum of the luminescent material is taken into account.

[0010] By such an invention, a light generating system can provide system light including a plurality of different wavelengths. In addition, the system can in particular provide such light by using a luminescent material, wherein the device light can be used to excite the luminescent material and provide the luminescent material light. By this system, wavelengths that are less converted but can be in UV or violet can be positioned at the edge of the radiation emitting surface, while the luminescent material light can basically escape from the central part of the radiation emitting surface. In addition, the system can be arranged in a single unit including a plurality of light generating devices, which can be particularly useful in many cases of practical use, such as for home, work, industrial lighting (where it may be difficult to accommodate a complex arrangement of many lighting devices). In addition, the system can be used to provide visible light or UV light and / or violet light, while also providing different types of light at the same time. In addition, by such an invention, a light generating system can be provided so that it can be used for disinfection in addition to lighting. In particular, such a light generating system can provide UV light and / or violet light that can be used to kill harmful microorganisms.

[0011] UV light has been used for disinfection for more than 100 years. Wavelengths between about 190nm and 300nm can be strongly absorbed by nucleic acids, which may cause defects in the genome of an organism. This may be desirable for inactivating (killing) bacteria and viruses, but may also have undesirable side effects in humans. Therefore, in environments where people may live, such as offices, public transportation, cinemas, restaurants, shops, etc., the choice of radiation wavelength, radiation intensity and radiation duration may be limited, thereby limiting the disinfection capacity. In particular, in such environments, additional disinfection measures may be beneficial to prevent the spread of bacteria and viruses, such as influenza or new (coronavirus) viruses, such as COVID-19, SARS and MERS. It seems desirable to produce systems that can provide alternative methods of air treatment (such as disinfection). In addition, existing disinfection systems may not be easily implemented in existing infrastructure, such as in existing buildings such as offices, hotel areas, and / or may not be easy to serve larger spaces. This may again increase the risk of contamination. In addition, incorporation into HVAC systems may not produce ideal results and seems relatively complicated. In addition, existing systems may not be efficient, or may be relatively bulky, or may not be easily incorporated into functional equipment such as lamps. Other disinfection systems can use one or more antimicrobial and / or antiviral means to disinfect a space or object. Examples of such means can be chemical agents that may be of concern. For example, chemical agents may also be harmful to humans and pets.

[0012] In an embodiment, the disinfecting light may particularly include ultraviolet (UV) radiation (and / or optionally violet radiation), i.e., the light may include a wavelength selected from the ultraviolet wavelength range (and / or optionally the violet wavelength range). However, other wavelengths are not excluded herein. The ultraviolet wavelength range is defined as light in the wavelength range of 100 nm to 380 nm, and can be divided into different types of UV light / UV wavelength ranges (Table 1). Radiation of different UV wavelengths may have different properties, and therefore may have different compatibilities with human presence, and may have different effects when used for disinfection (Table 1).

[0013] Table 1: Characteristics of different types of UV, ultraviolet and NIR wavelengths

[0014]

[0015]

[0016] Each UV type / wavelength range may have different advantages and / or disadvantages. Relevant aspects may be (relative) sterilization effect, safety (regarding radiation) and ozone generation (due to its radiation). Depending on the application, a specific type of UV light or a specific combination of UV light types may be selected that provides performance superior to other types of UV light. UV-A may be (relatively) safe and may inactivate (kill) bacteria, but may be less effective in inactivating (killing) viruses. When low doses (i.e., low exposure time and / or low intensity) are used, UV-B may be (relatively) safe, may inactivate (kill) bacteria, and may be moderately effective in inactivating (killing) viruses. UV-B may also have the added benefit that it may be effectively used to produce vitamin D in the skin of humans or animals. Near UV-C may be relatively unsafe, but may be effective in inactivating, particularly killing bacteria and viruses. Far UV-C may also be effective in inactivating (killing) bacteria and viruses, but may be (relatively) safe (relative to other UV-C wavelength ranges). Far UV light may generate some ozone that is harmful to humans and animals. Extreme UV-C can also effectively inactivate (kill) bacteria and viruses, but may be relatively unsafe. Extreme UV-C may generate ozone, which may be undesirable when exposed to humans or animals. In some applications, ozone may be needed and can help with disinfection, but shielding from humans and animals may be required. Therefore, in the table, a "+" for ozone production specifically indicates that the ozone produced can be useful for disinfection applications, but may be harmful when humans / animals come into contact with it. Therefore, in many applications, this "+" may actually be undesirable, while in other applications it may be desired. In an embodiment, the type of light indicated in the table above can be used to disinfect air and / or surfaces.

[0017] The terms "inactivate" and "kill" herein may particularly refer to destroying viruses in such a way that they can no longer infect and / or multiply in host cells, ie the viruses may be (substantially) harmless after inactivation or killing.

[0018] Thus, in embodiments, the light may include wavelengths within the UV-A range. In further embodiments, the light may include wavelengths within the UV-B range. In further embodiments, the light may include wavelengths within the near UV-C range. In further embodiments, the light may include wavelengths within the far UV-C range. In further embodiments, the light may include wavelengths within the extreme UV-C range. The near UV-C, far UV-C, and extreme UV-C ranges may also be collectively referred to herein as the UV-C range. Thus, in embodiments, the light may include wavelengths within the UV-C range. In other embodiments, the light may include violet radiation. Thus, the UV and / or violet light or radiation described herein may also be indicated as disinfecting light.

[0019] As previously mentioned, the present invention may provide a light generating system (or "system") configured to generate system light, wherein the light generating system may include (a) a plurality of sets of light generating devices and (b) luminescent materials. In particular, the light generating devices may be configured in an array, for example, the light generating devices may be arranged along a straight line, or alternatively, the light generating devices may be arranged in a 1D array or a 2D array. The array may be regular, random or quasi-random. In particular, in an embodiment, the array may be a regular 1D array or a regular 2D array. However, other arrays (such as leaf sequence mosaics or sunflower mosaics) may also be possible. However, in particular, the array may be a regular array. In an embodiment, the array is an n*m array, wherein n and m are each individually selected from a range of at least 3. In a specific embodiment, n and m are each individually selected from a range of 3-100. Therefore, in an embodiment, there may be one or two constant pitches. The term "mosaic" in this article may particularly refer to a pattern of (repeating) shapes, in particular polygons, which are closely packed together without gaps or overlaps. However, note that the array may also be a 1D array, for example when a filament is applied.

[0020] Furthermore, in an embodiment, the light generating device may be configured to generate device light. Here, "device light" is different from "system light". Device light may refer to light generated by one or more light generating devices. System light may refer to light generated by a light generating system. In particular, system light may include device light. Furthermore, system light may (also) include other light, such as luminescent material light (or "conversion device light" or "conversion light").

[0021] In an embodiment, the light generating device may not be limited to a device that generates device light, that is, in an embodiment. The light generating device may also include additional components or packaging of light generating elements, such as reflectors, lenses, reflectors, collimators, etc., to facilitate the generation and propagation of light. Therefore, the light generating device may not be limited to a light source, but may be a device including a light source and additional elements for providing or generating device light.

[0022] The light generating device may be particularly configured to generate device light. In particular, the light generating device may include a light source. The light source may be particularly configured to generate light source light. In embodiments, the device light may consist essentially of device light. In other embodiments, the device light may consist essentially of converted light source light. In other embodiments, the device light may include (unconverted) light source light and converted light source light. The light source light may be converted into luminescent material light with a luminescent material and / or into up-converted light with an up-converter (see also below). The term "light generating device" may also refer to a plurality of light generating devices that can provide device light with substantially the same spectral power distribution. In specific embodiments, the term "light generating device" may also refer to a plurality of light generating devices that can provide device light with different spectral power distributions.

[0023] The term "light source" may in principle relate to any light source known in the art. It may be a conventional (tungsten) bulb, a low-pressure mercury lamp, a high-pressure mercury lamp, a fluorescent lamp, an LED (light emitting diode). In a specific embodiment, the light source comprises a solid-state LED light source (such as an LED or a laser diode (or "diode laser")). The term "light source" may also relate to a plurality of light sources, such as a 2-2000 (solid-state) LED light source. Therefore, the term LED may also refer to a plurality of LEDs. In addition, in an embodiment, the term "light source" may also refer to a so-called chip-on-board (COB) light source. The term "COB" refers in particular to an LED chip in the form of a semiconductor chip, which is neither packaged nor connected but mounted directly on a substrate such as a PCB. Therefore, a plurality of light-emitting semiconductor light sources may be configured on the same substrate. In an embodiment, a COB is a multi-LED chip configured together as a single lighting module. The term "light source" may also refer to a chip-scale package (CSP). A CSP may include a single solid-state die on which a layer comprising a luminescent material is arranged. The term "light source" may also refer to a mid-power package. A mid-power package may include one or more solid-state dies. (Multiple) dies may be covered by a layer comprising a luminescent material. The die size may be equal to or less than 2 mm, such as in the range of 0.2 mm-2 mm. Thus, in an embodiment, the light source comprises a solid-state light source. Furthermore, in a specific embodiment, the light source comprises a chip-scale packaged LED. Here, the term "light source" may also particularly refer to a small solid-state light source, such as having a mini size or a micro size. For example, the light source may include one or more of a mini LED and a micro LED. In particular, in an embodiment, the light source comprises a micro LED or "microLED" or "μLED". Here, the term mini size or mini LED particularly refers to a solid-state light source having a size (such as a die size, particularly length and width) selected from the range of 100 μm-1 mm. Here, the term μ size or micro LED particularly refers to a solid-state light source having a size (such as a die size), particularly length and width, selected from the range of 100 μm and smaller.

[0024] A light source may have a light escape surface. For a conventional light source such as a light bulb or a fluorescent lamp, it may be the outer surface of a glass or quartz housing. For example, for an LED, it may be the LED die, or when a resin is applied to the LED die, it may be the outer surface of the resin. In principle, it may also be the terminal end of an optical fiber. The term escape surface particularly relates to that part of the light source, i.e. where the light actually leaves or escapes. The light source is configured to provide a light beam. This light beam (therefore) escapes from the light exit surface of the light source.

[0025] Likewise, the light generating device may comprise a light escape surface, such as an end window. Furthermore, also, the light generating system may comprise a light escape surface, such as an end window.

[0026] The term "light source" may refer to a semiconductor light emitting device, such as a light emitting diode (LED), a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSEL), an edge emitting laser, etc. The term "light source" may also refer to an organic light emitting diode (OLED), such as a passive matrix (PMOLED) or an active matrix (AMOLED). In a specific embodiment, the light source includes a solid-state light source (such as an LED or a laser diode). In an embodiment, the light source includes an LED (light emitting diode). The term "light source" or "solid-state light source" may also refer to a superluminescent diode (SLED). The term LED may also refer to a plurality of LEDs. The term "light source" may also refer to a plurality of (substantially the same (or different)) light sources, such as 2-2000 solid-state light sources. In an embodiment, the light source may include one or more micro-optical elements (micro-lens arrays) downstream of a single solid-state light source (such as an LED) or downstream of a plurality of solid-state light sources (i.e., shared by a plurality of LEDs). In an embodiment, the light source may include an LED with on-chip optics. In an embodiment, the light source includes a pixelated single LED (with or without optics) (on-chip beam control is provided in an embodiment). In an embodiment, the light source may be configured to provide primary radiation, which is used in this way, such as, for example, a blue light source, such as a blue LED, or a green light source, such as a green LED, and a red light source, such as a red LED. Such LEDs that may not include a luminescent material ("phosphor") may be indicated as direct color LEDs. However, in other embodiments, the light source may be configured to provide primary radiation, and a portion of the primary radiation is converted into secondary radiation. The secondary radiation may be based on the conversion of the luminescent material. Therefore, the secondary radiation may also be indicated as luminescent material radiation. In an embodiment, the luminescent material may be composed of a light source, such as an LED having a luminescent material layer or a dome including a luminescent material. Such an LED may be indicated as a phosphor conversion LED or a PC LED (phosphor conversion LED). In other embodiments, the luminescent material may be configured at a distance ("remote") from the light source, such as an LED having a luminescent material layer that is not in physical contact with the die of the LED. Therefore, in a particular embodiment, the light source may be a light source that emits at least a wavelength selected from the range of 380nm-470nm during operation. However, other wavelengths are also possible. This light may be partially used by the luminescent material.

[0027] In an embodiment, the light generating device may include a luminescent material. In an embodiment, the light generating device may include a PCLED. In other embodiments, the light generating device may include a direct LED (i.e., without a phosphor). In an embodiment, the light generating device may include a laser device, such as a laser diode. In an embodiment, the light generating device may include a super luminescent diode. Thus, in a particular embodiment, the light source may be selected from the group consisting of a laser diode and a super luminescent diode. In other embodiments, the light source may include an LED.

[0028] The light source may in particular be configured to generate a source light having an optical axis (O) (beam shape) and a spectral power distribution. In embodiments, the source light may comprise one or more bands, the bandwidth of which is known for lasers.

[0029] The term "light source" may (thus) refer to such a light generating element, for example a solid-state light source, or for example to a package of a light generating element, such as a solid-state power supply, and one or more luminescent materials, including elements and (other) optical devices, such as lenses, collimators. A light converting element ("converter element" or "converter") may include luminescent materials including elements. For example, a solid-state light source such as a blue LED is a light source. A combination of a solid-state light source (as light generating element) and a light converting element (such as a blue LED and a light converter element) optically coupled to a solid-state light source may also be a light source (but may also be indicated as a light generating device). Thus, a white LED is a light source (but may also be indicated as a (white) light generating device, for example).

[0030] The term "light source" herein may also refer to light sources including solid state light sources, such as LEDs or laser diodes or super luminescent diodes.

[0031] Thus, in embodiments, the term "light source" may also refer to a light source based on light conversion, such as a light source combined with a luminescence conversion material. Thus, the term "light source" may also refer to a combination of an LED and a luminescent material configured to convert at least part of the LED radiation, or a combination of a (diode) laser and a luminescent material configured to convert at least part of the (diode) laser radiation.

[0032] In an embodiment, the term "light source" may also refer to a combination of a light source (such as an LED) and a filter, which may change the spectral power distribution of the light generated by the light source. In particular, the term "light generating device" may be used to describe a light source and other (optical elements), such as filters and / or beam shaping elements, etc.

[0033] In an embodiment, the expression "different light sources" or "multiple different light sources" and similar expressions may refer to multiple solid-state light sources selected from at least two different intervals. Similarly, in an embodiment, the expression "same light source" or "multiple same light sources" and similar expressions may refer to multiple solid-state light sources selected from the same interval.

[0034] The terms "solid-state light source" or "solid-state material light source" and similar terms may particularly refer to semiconductor light sources, such as light emitting diodes (LEDs), diode lasers or superluminescent diodes.

[0035] In an embodiment, the plurality of sets of light generating devices may include at least two sets of light generating devices, more particularly at least three sets of light generating devices. In particular, the light generating devices in different sets may differ from each other in the peak wavelength of the device light. The device light may have a spectral distribution of wavelengths, wherein a specific wavelength corresponding to the highest intensity may be a peak wavelength. Thus, in an embodiment, (each) light generating device may have a unique peak wavelength, and therefore, one or more light generating devices may have one or more peak wavelengths, wherein each set of light generating devices may have a peak wavelength different from other sets.

[0036] In an embodiment, the light generating system may include multiple sets of light generating devices, such as at least three sets, such as at least six sets, and in particular at least ten sets. In particular, the first set of first light generating devices may be configured to provide a first device light having a first peak wavelength (λ1). The first peak wavelength may be in particular in the visible light wavelength range, in particular in the blue wavelength range. In addition, the second set of second light generating devices may be configured to generate a second device light having a second peak wavelength (λ2) in the UV wavelength range or in the violet wavelength range. In addition, in an embodiment, a third set of (optional) third light generating devices may be configured to generate a third device light having a third peak wavelength (λ3) in the UV wavelength range or in the violet wavelength range. Therefore, both the second peak wavelength and the third peak wavelength may be in the UV violet wavelength range.

[0037] The term "violet light" or "violet emission" particularly relates to light with a wavelength in the range of about 380nm-440nm. The term "blue light" or "blue emission" particularly relates to light with a wavelength in the range of about 440nm-495nm (including some violet and cyan). The term "green light" or "green emission" particularly relates to light with a wavelength in the range of about 495nm-570nm. The term "yellow light" or "yellow emission" particularly relates to light with a wavelength in the range of about 570nm-590nm. The term "orange light" or "orange emission" particularly relates to light with a wavelength in the range of about 590nm-620nm. The term "red light" or "red emission" particularly relates to light with a wavelength in the range of about 620nm-780nm. The term "pink light" or "pink emission" refers to light with blue and red components. The term "cyan" may refer to one or more wavelengths selected from the range of about 490nm-520nm. The term "amber" may refer to one or more wavelengths selected from the range of about 585nm-605nm, such as about 590nm-600nm. The expression "light having one or more wavelengths in the wavelength range" and similar expressions may specifically indicate that the indicated light (or radiation) has a spectral power distribution having at least an intensity at the one or more wavelengths in the indicated wavelength range. For example, a solid-state light source emitting blue will have a spectral power distribution with an intensity at one or more wavelengths in the wavelength range of 440nm-495nm. The phrase "UV ultraviolet" and similar phrases may specifically refer to radiation having a wavelength selected from the wavelength range of 100nm-440nm.

[0038] In an embodiment, the luminescent material may be configured downstream of the array of light generating devices. Here, the luminescent material may be configured along the path of the device light escaping from the (multiple) light generating devices. The luminescent material may be particularly configured to convert at least a portion of the first device light into luminescent material light. In addition, in an embodiment, at least a portion of the second device light or at least a portion of the third device light (or at least a portion of both) may be converted into luminescent material light. The luminescent material may convert light of one wavelength (e.g., device light) into light of another wavelength (e.g., luminescent material light). However, the intensity of the converted luminescent material light may depend on the wavelength of the device light incident on the luminescent material. Therefore, in an embodiment, the luminescent material may have different excitation intensities at different peak wavelengths (λ1, λ2, λ3). Therefore, by selecting the peak wavelength of one or more sets of light generating devices to be equal to the wavelength at which the luminescent material has a high excitation intensity, a high-intensity luminescent material light may be generated. Therefore, in an embodiment, the light generating devices in at least three sets may be configured for different excitation intensities at different peak wavelengths according to an increase or decrease in the excitation intensity of the luminescent material. Likewise, when there are only two sets of light generating devices, such as in a symmetrical arrangement, such as a concentric arrangement or a linear Bn2 A n1 B n2 This can be achieved by an arrangement where A refers to a first type of light generating device, such as a first light generating device, and n1≥1, and B refers to a second type of light generating device, such as a second light generating device, where n2≥1, and in a specific embodiment, n1>n2.

[0039] Likewise, when there are only three sets of light generating devices, such as in a symmetrical arrangement, such as a concentric arrangement, or a linear C n3 B n2 A n1 B n2 C n3 Arrangement, this can be done, where A refers to a first type of light generating device, such as a first light generating device, and n1≥1, B refers to a second type of light generating device, such as a second light generating device, where n2≥1, and C refers to a third type of light generating device, such as a third light generating device, where n3≥1. In a specific embodiment, n1>n2>n3.

[0040] The term "excitation intensity" as used in the specification and claims refers to the "oscillation intensity" of the luminescent material. In an embodiment, the luminescent material and the light generating device are selected, wherein the first light generating device has a peak length at a wavelength at which the luminescent material has a first oscillation intensity (O1), and the other type of light generating device (nth type) has a peak length at a wavelength at which the luminescent material has an nth oscillation intensity (O2). n ) has a peak wavelength λ n , where O n / O1≤0.5, such as O n / O1≤0.2, as in the embodiment, O n / O1≤0.1. The “other type” of light generating device (nth type) may be, for example, a third light generating device or, if applicable, a fourth light generating device. n The value of can decrease with the value of n.

[0041] In particular, the luminescent material can be configured in a transmissive mode. In the transmissive mode, it can be relatively easy to mix the light source light in the luminescent material light, which can help to generate a desired spectral power distribution. In the reflective mode, thermal management can be easier because a large portion of the luminescent material can be in thermal contact with a thermally conductive element (such as a heat sink or heat sink). Therefore, any device light will escape from the system, which in embodiments can be achieved only via transmission through the luminescent material. Luminescent materials and embodiments including such materials are discussed in more detail (see below).

[0042] The term "luminescent material" refers in particular to a material which can convert a first radiation, in particular one or more of UV radiation and blue radiation, into a second radiation. Typically, the first radiation and the second radiation have different spectral power distributions. Therefore, instead of the term "luminescent material", the term "luminescent converter" or "converter" may also be applied. Typically, the second radiation has a spectral power distribution at a larger wavelength than the first radiation, which is the case of so-called down-conversion. However, in a particular embodiment, the second radiation has a spectral power distribution which has an intensity at a smaller wavelength than the first radiation, which is the case of so-called up-conversion.

[0043] In an embodiment, a "luminescent material" may in particular refer to a material that is capable of converting radiation into, for example, visible light and / or infrared light. For example, in an embodiment, the luminescent material may be capable of converting one or more of UV radiation and blue radiation into visible light. In a particular embodiment, the luminescent material may also convert radiation into infrared radiation (IR). Thus, upon excitation with radiation, the luminescent material emits radiation. Typically, the luminescent material will be a downconverter, i.e., radiation of a smaller wavelength is converted into radiation of a larger wavelength (λ ex <λ em ), although in certain embodiments the luminescent material may comprise an upconverter luminescent material, ie radiation of a larger wavelength is converted to radiation of a smaller wavelength (λ ex >λ em ).

[0044] In an embodiment, the term "luminescence" may refer to phosphorescence. In an embodiment, the term "luminescence" may also refer to fluorescence. Instead of the term "luminescence", the term "emission" may also be applied. Thus, the terms "first radiation" and "second radiation" may refer to excitation radiation and emission (radiation), respectively. Likewise, in an embodiment, the term "luminescent material" may refer to phosphorescence and / or fluorescence.

[0045] The term "luminescent material" may also refer to a variety of different luminescent materials. Examples of possible luminescent materials are given below. Therefore, in certain embodiments, the term "luminescent material" may also refer to a luminescent material composition. Instead of the term "luminescent material", the term "phosphor" may also be used. These terms are known to those skilled in the art.

[0046] In an embodiment, the luminescent material is selected from garnets and nitrides, in particular doped with trivalent cerium or divalent europium, respectively. The term "nitride" may also refer to nitrogen oxides or nitrogen silicates, etc. Alternatively or additionally, the luminescent material may be selected from silicates, in particular doped with divalent europium.

[0047] In certain embodiments, the luminescent material comprises A3B5O 12: Ce type luminescent material. Wherein in an embodiment, A comprises one or more of Y, La, Gd, Tb and Lu, in particular (at least) one or more of Y, Gd, Tb and Lu, in an embodiment, B 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 in particular one or more of Y and Lu, in particular, B may comprise one or more of Al and Ga, more in particular at least Al, such as substantially completely Al. Therefore, a particularly suitable luminescent material is a cerium-containing garnet material. An embodiment of garnet in particular comprises A3B5O 12 Garnet, wherein A comprises at least yttrium or lutetium, wherein B comprises at least aluminum. Such garnet may be doped with cerium (Ce), praseodymium (Pr) or a combination of cerium and praseodymium; in particular Ce. In particular, B may comprise aluminum (Al); however, in addition to aluminum, B may also partially comprise gallium (Ga) and / or scandium (Sc) and / or indium (In), in particular up to about 20% B, more particularly up to about 10% B (i.e., the B ions are essentially composed of 90 mol % or more of Al and 10 mol % or less of one or more of Ga, Sc and In); B may in particular comprise up to about 10% gallium. In another variant, B and O may be at least partially replaced by Si and N. The element A may in particular be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb) and lutetium (Lu). Furthermore, the content of Gd and / or Tb is in particular only about 20% of A. In a specific embodiment, the garnet luminescent material includes (Y 1-x Lu x )3B5O 12 :Ce, wherein x is greater than or equal to 0 and less than or equal to 1. The term ":Ce" means that part of the metal ions in the luminescent material (i.e., part of the "A" ions in the garnet) are replaced by Ce. 1-x Lu 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 will usually replace A by no more than 10%; usually, the Ce concentration will be in the range of 0.1 to 4%, in particular 0.1 to 2% (relative to A). Assuming 1% cerium and 10% yttrium, a completely correct formula would be (Y 0.1 Lu 0.89 Ce 0.01 )3Al5O 12 The Ce in the garnet is substantially or exclusively in the trivalent state, as known to those skilled in the art.

[0048] In an embodiment, the luminescent material (therefore) comprises A3B5O 12, wherein in a particular embodiment, up to 10% of B-O can be replaced by Si-N.

[0049] In a particular embodiment, the luminescent material comprises (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O 12 , where x1 + x2 + x3 = 1, where x3 > 0, where 0 < x2 + x3 ≤ 0.2, where y1 + y2 = 1, where 0 ≤ y2 ≤ 0.2, and where A' comprises one or more elements selected from the group consisting of lanthanide elements, and where B' comprises one or more elements selected from Ga, In, and Sc. In the present invention, in particular, x1 > 0, such as > 0.2, e.g., at least 0.8. Garnets with Y can provide a suitable spectral power distribution.

[0050] In a particular embodiment, 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 (O refers to oxygen); in a particular embodiment, B-O can refer to Al-O. As mentioned above, in a particular embodiment, x3 can be selected from the range of 0.001 to 0.04. In particular, such a luminescent material can have a suitable spectral distribution (see below), have a relatively high efficiency, have a relatively high thermal stability, and allow a high CRI (optionally in combination with the light of other light sources described herein). Thus, in a particular embodiment, A can be selected from the group consisting of: Lu and Gd. Alternatively or additionally, B can include Ga. Thus, in an embodiment, the luminescent material comprises (Y x1-x2-x3 (Lu,Gd) x2 Ce x3 )3(Al y1-y2 Ga y2 )5O 12 , where Lu and / or Gd can be available. More specifically, x3 is selected from the range of 0.001 - 0.1, where 0 < x2 + x3 ≤ 0.1, and where 0 ≤ y2 ≤ 0.1. Furthermore, in a particular embodiment, up to 1% of B-O can be replaced by Si-N. Here, the percentage refers to the number of moles (as known in the art); see, for example, EP3149108. In another particular embodiment, the luminescent material comprises (Y x1-x3 Ce x3 )3Al5O 12 , where x1 + x3 = 1, and where 0 < x3 ≤ 0.2, such as 0.001 - 0.1.

[0051] In certain embodiments, the light generating device may include only a luminescent material selected from the cerium-containing garnet type. In additional specific embodiments, the light generating device includes a single type of luminescent material, such as (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1- y2 B' y2 )5O 12 . Thus, in certain embodiments, the light generating device includes a luminescent material, wherein at least 85 wt%, even more particularly at least about 90 wt%, such as even more particularly at least about 95 wt% of the luminescent material includes (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O 12 . Here, wherein A' includes one or more elements selected from the group consisting of lanthanide elements, and wherein B' includes one or more elements selected from the group consisting of Ga, In, and Sc, wherein x1 + x2 + x3 = 1, wherein x3 > 0, wherein 0 < x2 + x3 ≤ 0.2, wherein y1 + y2 = 1, wherein 0 ≤ y2 ≤ 0.2. In particular, x3 is selected from the range of 0.001 - 0.1. Note that in an embodiment, x2 = 0. Alternatively or additionally, in an embodiment, y2 = 0.

[0052] In certain embodiments, A may particularly include at least Y, and B may particularly include at least Al.

[0053] Alternatively or additionally, wherein the luminescent material may include a luminescent material of the A3Si6N 11 :Ce 3+ type, wherein A includes one or more of Y, La, Gd, Tb, and Lu, such as in an embodiment, one or more of La and Y.

[0054] In an embodiment, the luminescent material may alternatively or additionally include MS:Eu 2+ and / or M2Si5N8:Eu 2+ and / or MAlSiN3:Eu 2+ and / or Ca2AlSi3O2N5:Eu 2+One or more of the following, wherein M includes one or more of Ba, Sr and Ca, and in particular in an embodiment, includes at least Sr. Therefore, in an embodiment, the luminophore may include one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu and (Ba,Sr,Ca)2Si5N8:Eu. In these compounds, europium (Eu) is substantially or exclusively divalent and replaces one or more of the indicated divalent cations. Typically, the content of Eu will not exceed 10% of the cations; its presence will be particularly in the range of about 0.5% to 10%, more particularly in the range of about 0.5% to 5%, relative to the (multiple) cations it replaces. The term ":Eu" indicates that part of the metal ions are replaced by Eu (Eu in these examples). 2+ ) is substituted. For example, assuming that there is 2% Eu in CaAlSiN3:Eu, the correct formula would be (Ca 0.98 Eu 0.02 )AlSiN3. Divalent europium will typically replace divalent cations, such as the above-mentioned divalent alkaline earth cations, in particular Ca, Sr or Ba. The material (Ba,Sr,Ca)S:Eu can also be indicated as MS:Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); in particular, M includes calcium or strontium, or calcium and strontium, more particularly calcium in the compound. Here, Eu is introduced and replaces at least a portion of M (i.e., one or more of Ba, Sr and Ca). In addition, the material (Ba,Sr,Ca)2Si5N8:Eu can also be indicated as M2Si5N8:Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); in particular, M includes Sr and / or Ba in the compound. In another specific embodiment, M consists of Sr and / or Ba (excluding the presence of Eu), in particular 50% to 100%, more particularly 50% to 90% Ba and 50% to 0%, in particular 50% to 10% Sr, such as Ba 1.5 Sr 0.5 Si5N8:Eu (i.e., 75% Ba; 25% Sr). Here, Eu is introduced and replaces at least a portion of M, i.e., one or more of Ba, Sr and Ca. Similarly, the material (Ba,Sr,Ca)AlSiN3:Eu can also be indicated as MAlSiN3:Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); in particular, M in the compound includes calcium or strontium, or calcium and strontium, more particularly calcium. Here, Eu is introduced and replaces at least a portion of M (i.e., one or more of Ba, Sr and Ca). As known to those skilled in the art, Eu in the above-mentioned luminescent materials is substantially or only in a divalent state.

[0055] In an embodiment, the red light emitting material may include one or more materials selected from the group consisting of (Ba, Sr, Ca) S: Eu, (Ba, Sr, Ca) AlSiN3: Eu, and (Ba, Sr, Ca) 2Si5N8: Eu. In these compounds, europium (Eu) is substantially or only divalent and replaces one or more of the indicated divalent cations. Typically, the content of Eu does not exceed 10% of the cations; its presence will be particularly in the range of about 0.5% to 10%, more particularly in the range of about 0.5% to 5%, relative to the (multiple) cations it replaces. The term ": Eu" indicates that part of the metal ions are replaced by Eu (Eu in these examples). 2+ ) is substituted. For example, assuming that there is 2% Eu in CaAlSiN3:Eu, the correct formula would be (Ca 0.98 Eu 0.02 )AlSiN3. The divalent europium will usually replace a divalent cation, such as the above-mentioned divalent alkaline earth cation, in particular Ca, Sr or Ba.

[0056] The material (Ba, Sr, Ca) S: Eu may also be indicated as MS: Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); in particular, M includes calcium or strontium, or calcium and strontium, more particularly calcium in the compound. Here, Eu is introduced and replaces at least a portion of M (i.e., one or more of Ba, Sr and Ca).

[0057] In addition, the material (Ba, Sr, Ca) 2 Si 5 N 8 : Eu can also be indicated as M 2 Si 5 N 8 : Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); in particular, M includes Sr and / or Ba in the compound. In another specific embodiment, M consists of Sr and / or Ba (excluding the presence of Eu), in particular 50% to 100%, more particularly 50% to 90% Ba and 50% to 0%, in particular 50% to 10% Sr, such as Ba 1.5 Sr 0.5 Si5N8:Eu (ie, 75% Ba; 25% Sr) Here, Eu is introduced and replaces at least a part of M, ie, one or more of Ba, Sr and Ca.

[0058] Likewise, the material (Ba, Sr, Ca) AlSiN3:Eu may also be indicated as MAlSiN3:Eu. Wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); in particular, M includes calcium or strontium, or calcium and strontium, more particularly calcium in the compound. Here, Eu is introduced and replaces at least a portion of M (i.e., one or more of Ba, Sr and Ca).

[0059] As known to those skilled in the art, Eu in the above-mentioned luminescent materials is substantially or only in a divalent state.

[0060] The blue light emitting material may include YSO (Y2SiO5:Ce 3+ ) or similar compounds, or BAM (BaMgAl 10 O 17 :Eu 2+ ) or similar compounds.

[0061] The term "luminescent material" in this context particularly relates to inorganic luminescent materials.

[0062] Alternatively or additionally, other luminescent materials may also be applied. For example, quantum dots and / or organic dyes may be applied and may be optionally embedded in a transmissive matrix, such as a polymer, such as PMMA or polysiloxane, etc. Quantum dots are small crystals of semiconductor materials, usually with a width or diameter of only a few nanometers. When excited by incident light, the color of the light emitted by the quantum dots is determined by the size and material of the crystal. Therefore, light of a specific color may be generated by adapting the size of the dots. Most of the known quantum dots that emit in the visible range are based on cadmium selenide (CdSe), with shells such as cadmium sulfide (CdS) and zinc sulfide (ZnS). Cadmium-free quantum dots such as indium phosphide (InP), copper indium sulfide (CuInS2) and / or silver indium sulfide (AgInS2) may also be used. Quantum dots show very narrow emission bands, so they show saturated colors. In addition, by adapting the size of the quantum dots, the emission color may be easily tuned. Any type of quantum dots known in the art may be used in the present invention. However, for reasons of environmental safety and concern, it is preferred to use cadmium-free quantum dots or at least quantum dots with a very low cadmium content. Instead of or in addition to quantum dots, other quantum confinement structures can also be used. In the context of this application, the term "quantum confinement structure" should be understood as, for example, quantum wells, quantum dots, quantum rods, tripods, tetrapods or nanowires, etc. Organic phosphors can also be used. Examples of suitable organic phosphor materials are organic luminescent materials based on perylene derivatives, such as BASF's Examples of suitable compounds include, but are not limited to, Red F305, Orange F240, Yellow F083 and F170.

[0063] Different luminescent materials may have different spectral power distributions of the respective luminescent material light. Alternatively or additionally, such different luminescent materials may in particular have different color points (or dominant wavelengths).

[0064] As mentioned above, other luminescent materials are also possible. Therefore, in a particular embodiment, the luminescent material is selected from the group of: a nitride containing divalent europium, a nitrogen oxide containing divalent europium, a silicate containing divalent europium, a garnet containing cerium, and a quantum structure. The quantum structure may, for example, include quantum dots or quantum rods (or other quantum-type particles) (see above). The quantum structure may also include a quantum well. The quantum structure may also include a photonic crystal.

[0065] The luminescent material may consist of a luminophore. The luminophore may be a layer, such as a self-supporting layer. The luminophore may also be a coating. The luminophore may also include a luminescent coating on a support, in particular a light-transmitting support in transmission mode. In particular, the luminophore may be substantially self-supporting. In an embodiment, the luminescent material may be provided as a luminophore, such as a luminescent single crystal, a luminescent glass, or a luminescent ceramic body. Such a body may be indicated as a "converter body" or a "luminophore". In an embodiment, the luminophore may be a luminescent single crystal or a luminescent ceramic body. For example, in an embodiment, a cerium-containing garnet luminescent material may be provided as a luminescent single crystal or a luminescent ceramic body. In other embodiments, the luminophore may include a light-transmitting body in which a luminescent material is embedded. For example, the luminophore may include a glass body in which a luminescent material is embedded. Alternatively, the glass itself may be luminescent. In other embodiments, the luminophore may include a polymer body in which a luminescent material is embedded.

[0066] The luminescent material may not convert all of the light incident on the luminescent material, but may transmit some of the light. Therefore, the transmitted light may not be converted, and therefore, at least a portion of the light incident on the luminescent material may be transmitted at the same wavelength as the incident light. In an embodiment, the light generating device and the luminescent material may be configured such that at least a portion of the second device light and / or at least a portion of the third device light is transmitted by the luminescent material. Therefore, light comprising multiple wavelengths may be output from the light generating system. In particular, the system light may include device light (transmitted by the luminescent material) and luminescent material light (due to conversion of the device light by the luminescent material). Therefore, the spectral power distribution of the system light can be selected by combining different of the above-mentioned wavelengths.

[0067] In particular, in an embodiment, the light generating device and the luminescent material may be configured such that at least a portion of the first device light is transmitted by the luminescent material and at least a portion of the first device light is converted by the luminescent material into luminescent material light.

[0068] As previously mentioned, the luminescent material may have a relatively high excitation intensity at certain wavelengths, i.e., light of a specific wavelength incident on the luminescent material may be converted into luminescent material light of a different wavelength. Therefore, as previously mentioned, the device light and the luminescent material may be selected so that the peak wavelength of the device light is equal to the wavelength at which the luminescent material has a high excitation intensity. In particular, the luminescent material may have a (relatively) highest excitation intensity for the first device light. Therefore, in an embodiment, at least one set of light generating devices (such as the first light generating device) may have a peak wavelength that is substantially equal to the wavelength at which the luminescent material may have the highest excitation intensity.

[0069] System light may include a combination of transmitted light and converted light (ie, device light and luminescent material light).

[0070] In certain embodiments, at least 50% of the spectral power of the system light may be luminescent material light. This may be particularly beneficial for lighting purposes. Thus, in embodiments, the first light generating device may be a majority of the light generating devices comprised by the light generating system. However, in other embodiments, the percentage of radiation in the UV violet wavelength range and the percentage of radiation in the visible wavelength range may be controllable.

[0071] However, in addition to the first light generating system, a collection of light generating devices may (also) be needed to provide transmitted (rather than converted) light, e.g., if UV light is (at least partially) transmitted rather than (fully) converted, this is beneficial for disinfection purposes. Therefore, in an embodiment, the plurality of collections of light generating devices may include a collection of light generating devices having a peak wavelength for which the luminescent material has a very low excitation intensity. This will be discussed in more detail below.

[0072] The light generating system may comprise a plurality of sets of light generating devices. In particular, the number of light generating devices in a set is not necessarily equal, for example, the light generating system may comprise most of the light generating devices in a first set (ie, they generate a first device light).

[0073] As mentioned above, the light generating system may in particular include light generating devices configured as an array. In an embodiment, the distribution of the light generating devices in the array is not necessarily symmetrical. In particular, the array may include a 2D distribution of light generating devices, wherein the central area of ​​the array may be referred to as the core of the array and the area surrounding the central core may be referred to as the periphery of the array. The number of light generating devices in the core and peripheral parts of the array may be different (see below). The shape of the array may (also) vary in an embodiment. In particular, the array may have a circular, rectangular, square, pentagonal or hexagonal arrangement of light generating devices. In particular, in an embodiment, the distribution of the light generating devices in the array may be substantially symmetrical.

[0074] Thus, in an embodiment, the array may include a core array portion and a peripheral array portion, the core array portion including x1% of the total number of light generating devices, and the peripheral array portion including x2% of the total number of light generating devices. In addition, most of the light generating devices in which the luminescent material in the light generating devices has a relatively lower excitation intensity for the peak wavelength of the device light of the light generating devices can be configured in the peripheral array portion. In an embodiment, this can be the second light generating device, or the third light generating device or the nth light generating device. However, in an embodiment, the peripheral array portion may (also) include the first light generating device.

[0075] In addition, in an embodiment, most of the light generating devices in which the luminescent material in the light generating device has a relatively higher excitation intensity for the peak wavelength of the device light of the light generating device can be configured in the core array portion. In an embodiment, this can be the first light generating device. In addition, in an embodiment, the second light generating device, or the third light generating device or the nth light generating device (also) can be configured in the core array portion. In particular, x1% can be selected from the range of 5%-95%, such as 10%-90%, in particular 15-%85%. More specifically, x2% can be selected from the range of 5%-95%, such as 10%-90%, in particular 15%-85%. In a specific embodiment, x1% can be selected from the range of 20%-80%, such as 25%-75%. In particular, x2% can be selected from the range of 20%-80%, in particular 25%-75%. In particular, x1%+x2%=100%.

[0076] In an embodiment, x1% may be selected from the range of 50%-95%. Furthermore, in an embodiment, x2% may be selected from the range of 5%-50%. Thus, an embodiment of the light generating system may have at least half of the total number of light generating devices (the luminescent material having a high excitation intensity for its peak wavelength) configured in the core array portion. Furthermore, no more than half of the total number of light generating devices (the luminescent material having a low excitation intensity for its peak wavelength) may be configured in the peripheral array portion.

[0077] In an embodiment, at least 20% of the light generating devices may be first light generating devices. Furthermore, in an embodiment, at least 10% of the light generating devices may be second light generating devices. Furthermore, in an embodiment, at least 10% of the light generating devices may be third light generating devices. In an embodiment, at least 60% of the light generating devices may be defined by first light generating devices, second light generating devices and third light generating devices.

[0078] The array includes an edge array portion, which includes one or more rows. The edge array portion may also be referred to as an "edge array region" (or "end region"). The edge array portion includes a majority of light generating devices in which the luminescent material in the light generating device has a relatively lowest excitation intensity for the device light of the light generating device. In an embodiment, a collection of light generating devices (e.g., light generating devices with a peak wavelength in the UV light range) can be used for disinfection. Therefore, it may be advantageous to transmit (rather than convert) device light from such light generating devices. Therefore, in an embodiment, a majority of the light generating devices configured in the edge array portion may include light generating devices other than the first light generating device in the collection of light generating devices.

[0079] As previously described, the array may be a 1D or 2D array of light generating devices. The edge array portion in a 1D array may refer to one or more light generating devices at the edge (or end) of the array of light generating devices, and the edge array portion in a 2D array may refer to one or more row light generating devices at the edge of the array. That is, one or more rows of light generating devices may be the outermost rows of the array surrounding the remaining light generating devices. In particular, the light generating devices at the edge array portion may have a peak wavelength for which the luminescent material has the lowest excitation intensity. Therefore, the device light from one or more light generating devices in the edge array portion of the array may not be converted into high-intensity light. Therefore, the device light from most of the light generating devices at the edge array portion may be transmitted instead of converted. This can be particularly advantageous for disinfection purposes, for example, the system light may include unconverted UV light (from the light generating devices configured at the edge array portion).

[0080] Furthermore, in an embodiment, the plurality of sets of light generating devices may include at least n sets of light generating devices. In particular, the plurality of sets of light generating devices may include at least three sets, such as at least four sets, and in a particular embodiment, at least five sets of light generating devices.

[0081] Thus, in an embodiment, the light generating device may include a fourth set of fourth light generating devices configured to generate a fourth device light having a fourth peak wavelength (λ4) in the UV wavelength range, the violet wavelength range, or the visible wavelength range. In an embodiment, the light generating devices in at least n sets may be configured for different excitation intensities at different peak wavelengths according to an increase or decrease in the excitation intensity of the luminescent material. More generally, in an embodiment, the system may include a set of nth light generating devices configured to generate an nth device light having an nth peak wavelength (λn) in the UV wavelength range, the violet wavelength range, or the visible wavelength range, where n is 3, 4, or 5, where n=4, there is also a third set, when n=5, there are also the 3rd and 4th sets, and so on. Thus, in an embodiment, the luminescent material may be particularly configured to convert the first device light and at least a further portion of the second device light, and / or the third device light, and / or the nth device light into luminescent material light.

[0082] Thus, in an embodiment, the luminescent material and the light generating device may be configured such that the luminescent material is configured to convert at least a portion of the first device light into luminescent material light. Optionally, the luminescent material may also be configured to convert at least a portion of the device light of one or more light generating devices of the nth type of light generating device into luminescent material light. In addition, when there are multiple types of light generating devices, there may be (although not necessarily) a collection of light generating devices whose device light is not substantially converted by the luminescent material. In such an embodiment, at least a portion of the device light of this type of light generating device may be specifically transmitted by the luminescent material. In a specific embodiment, the luminescent material may be configured to convert at least a portion of the second device light and / or at least a portion of the third device light into luminescent material light (as well as at least a portion of the first device light).

[0083] It should be noted that the luminescent material may in particular have a relatively high excitation intensity corresponding to a specific peak wavelength of one or more light generating devices. However, for one or more other wavelengths, the luminescent material may have a relatively low excitation intensity. Or, in other words, the oscillation intensity may vary with wavelength. This may provide a (characteristic) excitation spectrum. Therefore, when the emission wavelength of the light source is changed while keeping its photon flux constant, the emission intensity of the luminescent material light will vary with the excitation wavelength. Therefore, even if the first light generating device, the second light generating device and the optional other light generating devices (such as the third light generating device) have equal photon flux, the radiant flux of the luminescent material light may be different for different light generating devices. In an embodiment, it may be desirable to select the radiant flux of the light generating device so that the radiant flux of the luminescent material light downstream of the luminescent material (respectively downstream of the light generating device) is substantially the same. In this way, the radiant flux of the luminescent material light on 75%-99% of the surface of the luminescent material may vary (only) within a range of + / -15% relative to the average radiant flux on the surface of the luminescent material, and even more particularly on at least 85%, such as at least 90%, of the surface of the luminescent material. In a particular embodiment, the radiant flux of the luminescent material light over at least 95% of the surface of the luminescent material may vary (only) within a range of + / -15% relative to the average radiant flux over the surface of the luminescent material. The variation may be even smaller, such as within about + / -10%, such as within about + / -5%. For example, the luminescent material may have increasing excitation intensities corresponding to the first device light, the second device light, and the third device light (i.e., in increasing order of excitation intensity from the third device light to the first device light).

[0084] However, the light generating system (in an embodiment) may be configured such that the intensity of the third device light may be higher than the intensity of the second device light, which in turn may be higher than the intensity of the first device light. As described above, this may result in substantially identical intensities of the luminescent material light of the corresponding first device light, second device light and third device light, but other configurations may also be selected. Therefore, alternative embodiments are also possible. This may be relevant, for example, when it is desired to focus more on aspects related to UV radiation rather than a uniform radiant flux. In particular, when the peripheral array portion is relatively small, a substantially uniform radiant flux of the luminescent material light may be applied to the core array portion, and not necessarily also to the peripheral array portion.

[0085] Thus, in certain embodiments, the photon flux of the device light may vary spatially across the luminescent material.Alternatively or additionally, in certain embodiments, the excitation wavelength of the device light may vary spatially across the luminescent material.

[0086] In other embodiments, the light generating system may be configured such that the photon fluxes of (the device lights of) the light generating devices are substantially equal.

[0087] In an alternative embodiment, the light generating system may be configured such that the radiant fluxes of (the device lights of) the light generating devices are substantially equal.

[0088] In another alternative embodiment, the light generating system can be configured such that the radiation flux of the light generating device (device light) can decrease as the indicated number of light generating devices of the corresponding type increases, that is, the radiation flux of the first light generating device (the first device light) is greater than the radiation flux of the second light generating device (the second device light), and the radiation flux of the second light generating device (the second device light) can in turn be greater than the radiation flux of an optional third light generating device (the third device light), and so on.

[0089] In an embodiment, the conversion rate of the luminescent material may therefore show an increasing trend with increasing excitation wavelength, particularly in the range of about 190nm-480nm, such as 230nm-480nm. Alternatively, in an embodiment, the conversion rate of the luminescent material may therefore show a decreasing trend with decreasing excitation wavelength, particularly in the range of about 480nm-190nm, such as 480nm-230nm.

[0090] Therefore, in the cross-sectional view, there may be at least one n5 D n4 C n3 B n2 A n1 B n2 C n3 D n4 E n5 An arrangement of an arrangement, wherein A refers to a first type of light generating device, such as a first light generating device, and n1≥1, and B refers to a second type of light generating device, such as a second light generating device, wherein n2≥1. In an embodiment, n2≥1 and n3≥1. Further, in an embodiment, n4≥0 and n5≥0, such as n4>0 and n5≥0. Further, in an embodiment, n1>n2+n3+n4+n5.

[0091] Here, the excitation intensities may be arranged so that they may have an increasing or decreasing trend over the wavelengths of the device lights of the plurality of sets from the light generating device. Furthermore, in an embodiment, the light generating device and the luminescent material may also be configured so that at least a portion of the second (and / or third) device light is transmitted by the luminescent material. This may be particularly advantageous for disinfection purposes, for example, the fourth device light may be selected from the wavelength range of UV light. Thus, in such an embodiment, most of the UV light may be transmitted without changing the wavelength of the UV light.

[0092] In an embodiment, (i) at least one of the at least three different sets of light generating devices may be configured to generate radiation having a peak wavelength in a wavelength range selected from the group of UV-A radiation, UV-B radiation, and near UV-C radiation, and (ii) at least another set of the at least three different sets of light generating devices may be configured to generate radiation having a peak wavelength in a violet wavelength range. With such an embodiment, a plurality of wavelengths may be provided, i.e., the system light may include a plurality of wavelengths. In particular, the system light may include at least a peak wavelength from the group of UV-A radiation, UV-B radiation, and near UV-C radiation. In an embodiment, a majority of the device light including the above wavelengths may be transmitted rather than converted (such as by a luminescent material). Furthermore, in an embodiment, the system light may include at least a peak wavelength in the violet wavelength range. Furthermore, in such an embodiment, a portion of the violet light may be converted, so that the system light may also include white light. Therefore, in a particular embodiment, the system light may include transmitted light from the group of UV-A radiation, UV-B radiation, and near UV-C radiation and (also) converted white light. Furthermore, in embodiments, at least two of the at least three different sets of light generating devices may be configured to generate radiation having a peak wavelength in a wavelength range selected from the group of UV-A radiation, UV-B radiation and near UV-C radiation.

[0093] In certain embodiments, all light generating devices may be configured in series. This may be convenient because power management of the light generating devices may be easily configured. Alternatively, in embodiments, the light generating devices may be configured in parallel. The choice of configuration of light generating devices in series or in parallel may depend on the desired arrangement of the light generating devices in the array.

[0094] In a particular embodiment, two or more sets may be individually controllable. In particular, in this way, the wavelength composition comprised by the system light may be selected. Thus, in an embodiment, two or more sets of at least two sets of light generating devices may be individually controllable. More specifically, in an embodiment, three or more sets of at least three sets of light generating devices may be individually controllable. More specifically, in an embodiment, each set may be individually controllable.

[0095] In an embodiment, the light generating system may include an LED filament. In particular, the LED filament may be configured to provide LED filament light. The term "LED filament light" may refer to the light of the LED filament during operation of the LED filament. The LED filament may include a plurality of light emitting diodes (LEDs) in an embodiment, in particular LEDs arranged in a linear array. The linear array may be a 1D or 2D array of n*m LEDs, wherein in an embodiment, n may be selected from a range of 1-4, such as 1-3, such as 1-2, such as 1 in an embodiment, or 2 in an embodiment, and m may be selected from a range greater than n, such as in particular a range of at least 4 (when n<4), such as at least 6, such as at least 8. In addition, the LEDs may be arranged to emit, for example, LED light of different colors or spectral power distributions. In an embodiment, two or more LEDs may be configured to provide light having substantially the same spectral power distribution. More specifically, in an embodiment, all LEDs may be configured to provide light having substantially the same spectral power distribution. In some further embodiments, two or more LEDs may be configured to provide light having different spectral power distributions.

[0096] In an embodiment, the LED filament may have a length L and a width W, in a particular embodiment, L ≥ 5 W. The LED filament may be arranged in a straight configuration or a non-straight configuration, such as a meander configuration, a (2D or 3D) spiral, or a helix.

[0097] In a particular embodiment, the LEDs may be arranged on an (elongated) carrier, such as a substrate. In an embodiment, the (elongated) carrier may be rigid (e.g. made of a polymer, glass, quartz, metal or sapphire) or flexible (e.g. made of a polymer or metal, such as a film or foil).

[0098] In case the carrier comprises a first main surface and an opposite second main surface, the LED is arranged on at least one of these surfaces. In an embodiment, the carrier may be light reflective, in particular reflective to the filament light. In an embodiment, the carrier may be light transmissive, such as translucent, in a particular embodiment, transparent.

[0099] In an embodiment, the LED filament may include an encapsulant at least partially covering at least a portion of the total number of LEDs (of the plurality of LEDs).In a particular embodiment, the encapsulant may also at least partially cover at least one of the first major surface or the second major surface.

[0100] The sealant may comprise a polymer material, which in embodiments may be flexible, such as silicone. In embodiments, the sealant may comprise a resin.

[0101] In an embodiment, the encapsulant may include one or more of a luminescent material and a light scattering material. Here, in particular, the LED filament comprises at least a luminescent material. One or more of the luminescent material and the light scattering material may be embedded in an encapsulation material, such as a polymer material. The luminescent material may in particular be configured to at least partially convert the LED light into converted light. The luminescent material may also be indicated as a "phosphor". The luminescent material may include a phosphor, for example an inorganic phosphor and / or quantum dots or rods.

[0102] Thus, in certain embodiments, LED filament light may include one or more of LED light and converted light ("luminescent material light").

[0103] In an embodiment, an LED filament may include multiple sub-filaments.

[0104] As described above, in an embodiment, the LED filament may include a plurality of light emitting diodes. However, in the context of the LED filament, the term LED may also refer to a solid state light source (generally). Thus, the LED filament may include one or more of an LED, a laser diode, and a superluminescent diode. In particular, the LED filament includes a plurality of light emitting diodes (LEDs).

[0105] In particular, the LED filament may comprise an array of light generating devices. More specifically, at least the second light generating device and the third light generating device may be configured at one or both ends of the LED filament. In embodiments, the LED filament may comprise a plurality of sets of light generating devices. Thus, in embodiments, the LED filament may (also) provide system light. More specifically, in embodiments, the system light comprises the LED filament light.

[0106] In an embodiment, the light generating system may include a chip on board (or "COB") light generating device. In particular, the COB light generating device may include an array of light generating devices. Here, the array may be a 2D arrangement of light generating devices. In particular, the 2D array may include a core array portion and a peripheral array portion. More specifically, the core array portion may be located at the center of the COB light generating device, and the peripheral array portion is configured to surround and enclose the core array portion. In addition, in an embodiment, the light generating system may further include a light emitting layer containing a luminescent material. Therefore, the COB light generating device may provide a system light including a combination of luminescent material light and device light. In particular, the luminescent material may be configured downstream of the chip on board light generating device. Here, downstream refers to an element configured further along the light path of the light escaping from the COB light generating device. As previously described, in an embodiment, the peripheral array portion may surround the core array portion. In particular, the first light generating device may be configured in the core array portion, and the other light generating devices may be configured in the peripheral array portion. More specifically, the core array portion includes a center, wherein the excitation intensity may decrease as the distance from the center increases. In an embodiment, the light emitting layer may be deposited on the COB.

[0107] In an embodiment, the COB light generating device may include most of the light generating devices in the core array portion of the light generating device configured around the center, and the remaining light generating devices configured at the periphery. In particular, device light including a peak wavelength with a higher excitation intensity may be configured at the center, for example, a first set of multiple sets of light generating devices may be configured at the center, which may be followed by a second set around the first set, and so on. Therefore, in such an embodiment, the device light at the center of the array may be converted into luminescent material light of the highest excitation intensity, while the device light at the periphery may be transmitted with minimal conversion (or converted at the lowest excitation intensity). Therefore, this may provide the advantage of providing system light that may include multiple wavelengths of light in addition to the transmitted UV light. Therefore, the light generating system may provide lighting and be used for disinfection at the same time.

[0108] In an embodiment, the luminescent material may have a luminescent material surface. In particular, the radiant flux of the luminescent material light on 75%-99% (such as 85%-99%, in particular 95%-99%) of the luminescent material surface may vary within a range of + / -15% relative to the average radiant flux on the luminescent material surface. There may be slight variations in the radiant flux on the luminescent material surface. However, in an embodiment, the arrangement of the light generating devices in the array may be such that the variation in the radiant flux on most of the luminescent material surface may be in particular within a range of + / -25%, such as + / -15%, in particular + / -10%, relative to the average radiant flux on the luminescent material surface. Therefore, by such an embodiment, a system light with a uniform radiant flux may be provided.

[0109] The light generating system may be part of or may be applied to an office lighting system, a home application system, a shop lighting system, a household lighting system, an accent lighting system, a spotlight system, a theatre lighting system, a fibre optic application system, a projection system, a self-luminous display system, a pixelated display system, a segmented display system, a warning sign system, a medical lighting application system, a signage system, a decorative lighting system, a portable system, an automotive application, a (outdoor) road lighting system, a city lighting system, a greenhouse lighting system, a horticultural lighting, digital projection or an LCD backlight. For example, the light generating system (or lamp) may be part of or may be applied to an optical communication system or a disinfection system.

[0110] As described above, the lighting unit can be used as a backlight unit in an LCD display device. Therefore, the present invention also provides an LCD display device comprising a lighting unit as described herein, configured as a backlight unit. The present invention also provides a liquid crystal display device comprising a backlight unit on the other hand, wherein the backlight unit comprises one or more light generating systems as described herein.

[0111] The terms "upstream" and "downstream" relate to the arrangement of items or features relative to the propagation of light from a light generating component (here particularly a light source), wherein, relative to a first position within a light beam from the light generating component, a second position in the light beam closer to the light generating component is "upstream" and a third position within the light beam further away from the light generating component is "downstream".

[0112] The term "white light" and similar terms herein are known to a person skilled in the art. It particularly relates to light having a correlated color temperature (CCT) between about 1800K and 20000K, such as between 2000K and 20000K, in particular between 2700K-20000K, for general lighting, in particular in the range of about 2000K-7000K, such as in the range of about 2700K to 6500K. In an embodiment, for example, for backlighting purposes, or for other purposes, the correlated color temperature (CCT) may in particular be in the range of about 7000K to 20000K. Furthermore, in an embodiment, the correlated color temperature (CCT) is in particular within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), in particular within about 10 SDCM from the BBL, even more in particular within about 5 SDCM from the BBL. In a particular embodiment, the correlated color temperature (CCT) may be selected from the range of 6000K-12000K, such as from the range of 7000K-12000K, such as at least 8000 K. Furthermore, in an embodiment, the correlated color temperature (CCT) may be selected from the range of 6000K-12000K, such as from the range of 7000K-12000K, in combination with a CRI of at least 70.

[0113] In an embodiment, the system light may be white light having a correlated color temperature in the range of 1800K to 6500K. Here, the correlated color temperature (CCT) is a measure of the color appearance of a light source, defined by the proximity of the chromaticity coordinates of the light source to the black body locus, and is a single number, rather than the two numbers required to specify the chromaticity. In addition, in an embodiment, the system light may have a color rendering index of at least 80, such as at least 85, and in particular at least 90. The color rendering index (CRI) is a quantitative measure of the ability of a light source to faithfully display the colors of various objects compared to a natural or standard light source. The CRI is determined by the spectrum of the light source. The "CRI" values ​​often quoted on commercial lighting products are correctly called CIE Ra values, "CRI" is a general term, and CIE Ra is the International Standard Color Rendering Index. Numerically speaking, the highest CIE Ra value can be 100, and only applies to light sources with a spectrum identical to the spectrum of daylight, very close to the spectrum of a black body (incandescent lamps are actually black bodies), and for some light sources, its value drops to negative values.

[0114] The terms "visible", "visible light" or "visible emission" and similar terms refer to light having one or more wavelengths in the range of about 380nm-780nm. Here, UV may in particular refer to a wavelength selected from the range of 190nm-380nm, such as 200nm-380nm. In particular embodiments, the term UV radiation may refer to near UV radiation (NUV). Therefore, the term "(N)UV" is also applied herein, which refers to UV in general and NUV in particular embodiments. In particular embodiments, the term IR radiation may refer to near IR radiation (NIR). Therefore, the term "(N)IR" is also applied herein, which refers to IR in general and NIR in particular embodiments. Here, IR (infrared) may in particular refer to radiation having a wavelength selected from the range of 780nm-3000nm, such as 780nm-2000nm, for example a wavelength of up to about 1500nm, such as a wavelength of at least 900nm. But in particular embodiments, other wavelengths are also possible. Thus, the term IR herein may refer to one or more of near infrared (NIR (or IR-A)) and short wave infrared (SWIR (or IR-B)), in particular NIR.

[0115] In an embodiment, the light generating system may comprise a control system.In particular, the control system may be configured to control (or operate in an operating mode) one or more sets of light generating devices.

[0116] The term "control" and similar terms particularly refer to at least determining the behavior of an element or supervising its operation. Therefore, herein, "control" and similar terms may refer to applying behavior (determining the behavior or supervising the operation of an element) to an element, such as, for example, measuring, displaying, actuating, opening, moving, changing temperature, etc. In addition, the term "control" and similar terms may also include monitoring. Therefore, the term "control" and similar terms may include applying behavior to an element, and also include imposing behavior and monitoring elements on an element. The control of an element may be performed by a control system, which may also be indicated as a "controller". Therefore, the control system and the element may be functionally coupled at least temporarily or permanently. The element may include a control system. In an embodiment, the control system and the element may not be physically coupled. Control may be performed via wired and / or wireless control. The term "control system" may also refer to a plurality of different control systems, which are particularly functionally coupled, wherein, for example, one control system may be a master control system, and one or more other control systems may be slave control systems. The control system may include or may be functionally coupled to a user interface.

[0117] The control system may also be configured to receive and execute instructions from a remote control. In an embodiment, the control system may be controlled via an application on a device, such as a portable device, such as a smartphone or I-phone, a tablet, etc. Thus, the device is not necessarily coupled to the lighting system, but may be (temporarily) functionally coupled to the lighting system.

[0118] Thus, in an embodiment, the control system may (also) be configured to be controlled by an application on a remote device. In such an embodiment, the control system of the lighting system may be a slave control system or a control in slave mode. For example, the lighting system may be identifiable with a code, in particular a unique code of the respective lighting system. The control system of the lighting system may be configured to be controlled by an external control system, which may access the lighting system based on the knowledge of the (unique) code (input by a user interface with an optical sensor (e.g. a QR code reader)). The lighting system may also comprise components for communicating with other systems or devices, such as based on Bluetooth, Thread, WIFI, LiFi, ZigBee, BLE or WiMAX or another wireless technology.

[0119] A system, device or apparatus may perform actions in a "mode" or "operating mode" or "operable mode". The term "operable mode" may also be indicated as a "control mode". Similarly, in a method, an action or phase or step may act in a "mode" or "operating mode" or "operable mode". This does not exclude that a system, device or apparatus may also be adapted to provide another control mode or multiple other control modes. Similarly, this may not exclude that one or more other modes may be executed before and / or after executing the mode.

[0120] However, in an embodiment, a control system may be provided, which is adapted to provide at least a control mode. If other modes are available, the selection of such a mode may in particular be performed via a user interface, although other options (such as executing a mode according to a sensor signal or a (time) scheme) are also possible. In an embodiment, an operating mode may also refer to a system, device or apparatus that can only be operated in a single operating mode (i.e. "on", without further adjustability).

[0121] Therefore, in an embodiment, the control system may be controlled according to 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.

[0122] In yet another aspect, the present invention also provides a lamp or lamp comprising a light generating system as defined herein. The lamp may also include a housing, an optical element, a shutter, etc. The lamp or lamp may also include a housing surrounding the light generating system. The lamp or lamp may include a light window in the housing, or a housing opening, through which the system light can escape from the housing. In yet another aspect, the present invention also provides a projection device comprising a light generating system as defined herein. In particular, a projection device or "projector" or "image projector" may be an optical device that projects an image (or moving image) onto a surface, such as a projection screen. The projection device may include one or more light generating systems, such as those described herein. Therefore, in one aspect, the present invention also provides a light generating device comprising a light generating system as defined herein, the light generating device being selected from the group consisting of a lamp, a lamp, a projection device, a disinfection device, a photochemical reactor, and an optical wireless communication device. The light generating device may include a housing or carrier configured to accommodate or support one or more elements of the light generating system. BRIEF DESCRIPTION OF THE DRAWINGS

[0123] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which corresponding reference characters indicate corresponding parts, and in which:

[0124] Figure 1 Schematically depicts a top view and a cross-sectional view of one embodiment of a light generating system.The figure (also) depicts the wavelength distribution corresponding to the first device light, the second device light and the third device light.

[0125] Figure 2 The excitation spectra of the luminescent materials are schematically depicted.

[0126] Figure 3 One embodiment of an LED filament is schematically depicted.

[0127] Figure 4 An embodiment of a luminaire 2 comprising a light generating system 1000 is schematically depicted.

[0128] The schematic diagrams are not necessarily drawn to scale. DETAILED DESCRIPTION

[0129] Figure 1 A cross-sectional view (I) and a top view (II) of one embodiment of a light generating system are schematically depicted. In addition, the figure depicts multiple sets of one or more light generating devices (III). The figure (also) depicts wavelength distributions corresponding to first device light, second device light, and third device light (IV).

[0130] In an embodiment, the present invention may provide a light generating system 1000. In particular, the light generating system may include (a) a plurality of sets 150 of light generating devices 100 and (b) a luminescent material 200. The light generating devices 100 may be configured in an array 40. In addition, the light generating devices 100 may be configured to generate device light 101. In particular, the light generating devices 100 may include a solid-state light source. In addition, in an embodiment, the plurality of sets 150 of light generating devices 100 may include at least three sets 50 of light generating devices 100. In particular, the light generating devices 100 in different sets may differ from each other in the peak wavelength of the device light 101. In particular, the first set of first light generating devices 110 can be configured to provide first device light 111 having a first peak wavelength (λ1) in the visible wavelength range, particularly in the blue wavelength range, the second set of second light generating devices 120 can be configured to generate second device light 121 having a second peak wavelength (λ2) in the UV wavelength range or in the violet wavelength range, and the third set of third light generating devices 130 can be configured to generate third device light 131 having a third peak wavelength (λ3) in the UV wavelength range or in the violet wavelength range.

[0131] In an embodiment, the luminescent material 200 may be configured downstream of the array 40 of light generating devices 100. In particular, the luminescent material 200 may be configured to convert at least a portion of the first device light 101 into the luminescent material light 201. Furthermore, in an embodiment, the luminescent material 200 may be configured to convert at least a portion of the second device light 121 and / or at least a portion of the third device light 131 into the luminescent material light 201. More particularly, the luminescent material 200 may have different excitation intensities at different peak wavelengths (λ1, λ2, λ3). The different excitation intensities of the luminescent material in a particular embodiment are shown as (IV). For example, the excitation maximum may be about 455 nm, about 340 nm, and about 225 nm in order of decreasing excitation intensity.

[0132] Thus, as schematically depicted, λ1 may be, for example, about 455 nm, λ2 may be, for example, about 340 nm, and λ1 may be, for example, about 225 nm. However, in one example, while keeping λ1 and λ2 substantially the same, λ3 may also be, for example, selected as a minimum value between the maximum values ​​at about 225 nm and 340 nm, or between the maximum values ​​at about 340 nm and 455 nm. However, other embodiments are also possible.

[0133] The conversion rate of the luminescent material may show an increasing trend with increasing excitation wavelength, particularly in the range of about 190 nm-480 nm, such as 230 nm-480 nm.

[0134] In an embodiment, the light generating devices 100 in at least three sets 50 are configured for different excitation intensities at different peak wavelengths according to an increase or decrease in the excitation intensity of the luminescent material 200 .

[0135] In an embodiment, the light generating device 100 and the luminescent material 200 may be configured such that at least a portion of the second device light 121 and / or at least a portion of the third device light 131 is transmitted by the luminescent material 200. In particular, the light generating device 100 and the luminescent material 200 may be configured such that at least a portion of the first device light 111 may be transmitted by the luminescent material 200, and at least a portion of the first device light 111 may be converted by the luminescent material 200 into luminescent material light 201.

[0136] In an embodiment, the array 40 may include a core array portion 61 and a peripheral array portion 62, wherein the core array portion includes x1% of the total number of light generating devices 100 and the peripheral array portion includes x2% of the total number of light generating devices 100. Such an embodiment is shown in (II). In particular, most of the light generating devices in which the luminescent material 200 in the light generating device 100 has a relatively lower excitation intensity for the peak wavelength of the device light 101 of the light generating device can be configured in the peripheral array portion 62, and most of the light generating devices in which the luminescent material 200 in the light generating device 100 has a relatively higher excitation intensity for the peak wavelength of the device light 101 of the light generating device can be configured in the core array portion 61. In particular, x1% can be selected from the range of 5%-95%, wherein x2% can be selected from the range of 5%-95%. In particular, x1%+x2%=100%.

[0137] In an embodiment, the luminescent material 200 may have a luminescent material surface 220. In particular, the radiant flux of the luminescent material light 201 on 75%-99% of the luminescent material surface 220 may vary within a range of + / -15% relative to the average radiant flux on the luminescent material surface 220.

[0138] In an embodiment, the array 40 may include an edge array portion 41 including one or more rows 49. In particular, the edge array portion 41 may include a majority of light generating devices 100 where the luminescent material 200 has a relatively lowest excitation intensity for a peak wavelength of the device light 101 of the light generating devices.

[0139] In an embodiment, the light generating system 1000 may include a chip-on-board light generating device 1400, which includes an array 40 of light generating devices 100, as shown in (II). In particular, the light generating system 1000 may also include a light emitting layer 1500, which includes a light emitting material 200 configured downstream of the chip-on-board light generating device 1400. In particular, the peripheral array portion 62 may surround the core array portion 61. In addition, in an embodiment, the first light generating device 110 may be configured in the core array portion 61, wherein the other light generating devices 120, 130 may be configured in the peripheral array portion 62. In particular, the core array portion 61 may include a center 63, and the excitation intensity decreases as the distance from the center 63 increases. In an embodiment, x1% may be selected from the range of 20%-80%, and in particular, x2% may be selected from the range of 20%-80%.

[0140] Referring to, for example, Embodiments I and II, the excitation wavelength of the device light (101) can thus be varied spatially across the light emitting material 200.

[0141] In an embodiment, (i) at least one of the at least three different sets 50 of light generating devices 100 may be configured to generate radiation having a peak wavelength within a wavelength range selected from the group consisting of UV-A radiation, UV-B radiation, and near UV-C radiation, and (ii) at least another of the at least three different sets 50 of light generating devices 100 may be configured to generate radiation having a peak wavelength within a violet wavelength range. Furthermore, in an embodiment, at least two of the at least three different sets 50 of light generating devices 100 may be configured to generate radiation having a peak wavelength within a wavelength range selected from the group consisting of UV-A radiation, UV-B radiation, and near UV-C radiation.

[0142] In an embodiment, the luminescent material 200 may include A3B5O 12 :Ce type luminescent material, wherein A includes one or more of Y, La, Gd, Tb and Lu, and wherein B includes one or more of Al, Ga, In and Sc. In addition, in an embodiment, the system light can be white light with a correlated color temperature in the range of 1800K to 6500K and a color rendering index of at least 80.

[0143] In an embodiment, all light generating devices 100 may be configured in series.In particular, two or more of the at least two sets 50 of light generating devices 100 may be individually controlled.

[0144] Figure 2The excitation spectrum of the luminescent material is schematically depicted. In an embodiment, the luminescent material 200 may have a relatively highest excitation intensity for the first device light 111. In particular, the luminescent material 200 may be configured to convert at least a portion of the device light 101 into luminescent material light 201.

[0145] More specifically, the luminescent material 200 may have different excitation intensities at different peak wavelengths. In particular, the light generating devices 100 in at least three sets 50 may be configured for different excitation intensities at different peak wavelengths according to an increase or decrease in the excitation intensity of the luminescent material 200. In the figure, the solid line depicts the excitation spectrum, i.e., the wavelength of the incident device light 101, where there is a corresponding emission spectrum of the luminescent material light 201 (different wavelengths). In a particular embodiment, the highest intensity of the converted light may correspond to the first device light 111, while other wavelengths such as the second device light 121 and the third device light 131 may have the lowest excitation intensity.

[0146] Figure 3 Several embodiments of an LED filament 1100 are schematically depicted. In an embodiment, the light generating system 1000 may include an LED filament 1100. In particular, the LED filament 1100 may include an array 40 of light generating devices 100. In an embodiment, the LED filament 1100 may include a first light generating device 110, a second light generating device 120, or a third light generating device 130, or a fourth light generating device 140, or a combination thereof. In particular, at least the second light generating device 120 and the third light generating device 130 may be configured at one or both ends 1101, 1102 of the LED filament 1100. Furthermore, in an embodiment, the plurality of sets 150 of light generating devices 100 may include at least n sets 50 of light generating devices 100. In particular, n=4, wherein the light generating device 100 includes a fourth set of fourth light generating devices 140 configured to generate a fourth device light 141 having a fourth peak wavelength (λ4) in the UV wavelength range, or in the violet wavelength range, or in the visible wavelength range.

[0147] In an embodiment, the light generating devices 100 in the at least n sets 50 may be configured for different excitation intensities at different peak wavelengths according to an increase or decrease in the excitation intensity of the luminescent material 200 .

[0148] Figure 4 An embodiment of a luminaire 2 comprising a light generating system 1000 as described above is schematically depicted. Reference numeral 301 denotes a user interface which may be functionally coupled with a control system 300 comprised by the light generating system 1000 or functionally coupled to the light generating system 1000. Figure 3Also schematically depicted is an embodiment of a lamp 1 comprising a light generating system 1000. Reference numeral 3 denotes a projection device or a projection system which may be used for projecting an image, such as at a wall, which projection device or projection system may also comprise the light generating system 1000. Thus, Figure 4 Schematically depicted is an embodiment of a lighting device 1200 comprising a light generating system 1000 described herein, the lighting device being selected from the group of items: a lamp 1, a lamp fixture 2, a projection device 3, a disinfection device, a photochemical reactor, and an optical wireless communication device. In an embodiment, such a lighting device may be a lamp 1, a lamp fixture 2, a projection device 3, a disinfection device, or an optical wireless communication device. Lighting device light escaping from the lighting device 1200 is indicated by reference numeral 1201. Lighting device light 1201 may essentially consist of system light 1001, and may therefore be system light 1001 in a particular embodiment. In an embodiment, the light generating device 1200 may be configured to provide system light 1001 on one or more surfaces in a room 1300. In particular, the light generating system 1000 may illuminate a wall 1307, a floor 1305, or a ceiling 1310 in the room 1300.

[0149] The term "plurality" refers to two or more. Those skilled in the art will understand the term "substantially" or "substantially" and similar terms herein. The term "substantially" or "substantially" may also include embodiments with "complete", "completely" or "all" and the like. Therefore, in an embodiment, the adjective "substantially" or "substantially" may also be deleted. Where applicable, the term "substantially" or the term "substantially" may also refer to 90% or more, such as 95% or more, particularly 99% or more, and even more particularly 99.5% or more (including 100%). The term "comprising" also includes embodiments in which the term "comprising" means "consisting of". The term "and / or" particularly relates to one or more items mentioned before and after "and / or". For example, the expression "item 1 and / or item 2" and similar expressions may be related to one or more of item 1 and item 2. In one embodiment, the term "comprising" may refer to "consisting of", but in another embodiment, it may also refer to "at least comprising the defined species and one or more optional other species". In addition, the terms first, second, third, etc. in the specification and claims are used to distinguish similar elements, and are not necessarily used to describe order or chronological order. It should be understood that the terms used in this way are interchangeable where appropriate, and that the embodiments of the invention described herein can operate in other orders than those described or shown herein. The use of the verb "comprise" and its variants does not exclude the presence of elements or steps other than those described in the claims. Unless the context clearly requires otherwise, throughout the specification and claims, words such as "comprises", "comprising", etc. should be interpreted as being inclusive, not exclusive or exhaustive; that is, in the sense of "including but not limited to". The "one" or "an" clause before an element does not exclude the presence of multiple such elements.

[0150] Devices, apparatuses or systems etc. may be described herein during operation. It will be clear to those skilled in the art that the present invention is not limited to methods of operation or devices, apparatuses or systems in operation.

[0151] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.In the claims, any reference signs between parentheses shall not be construed as limiting the claim.

[0152] The present invention may be implemented by hardware including several different elements and by a suitably programmed computer. In a device claim, an apparatus claim or a system claim that lists a plurality of means, several of these means may be implemented by the same hardware. The fact that certain measures are cited in mutually different dependent claims does not mean that a combination of these measures cannot be used to advantage. On the other hand, the present invention (therefore) provides a software product that, when run on a computer, is capable of implementing (one or more embodiments of) the method described herein. The present invention also provides a control system that can control a device, an apparatus or a system, or can perform the method or process described herein. In addition, the present invention also provides a computer program product that, when run on a computer functionally coupled to or consisting of a device, an apparatus or a system, controls one or more controllable elements of such a device, an apparatus or a system. The present invention is also applicable to a device, an apparatus or a system comprising one or more features described in the specification and / or shown in the accompanying drawings. The present invention also relates to a method or process comprising one or more features described in the specification and / or shown in the accompanying drawings.

[0153] The various aspects discussed in this patent can be combined to provide additional advantages. In addition, those skilled in the art will appreciate that the embodiments can be combined, and more than two embodiments can also be combined. In addition, some features can form the basis of one or more partition applications.

Claims

1. A light generating system (1000) comprising (a) a plurality of sets (150) of light generating devices (100) and (b) a luminescent material (200) configured to generate visible light, wherein: - the light generating devices (100) are arranged in an array (40); wherein the light generating devices (100) are arranged to generate device light (101); wherein the light generating devices (100) comprise solid state light sources; - the plurality of sets (150) of light generating devices (100) comprise at least three sets (50) of light generating devices (100), wherein the light generating devices (100) in different sets differ from each other in the peak wavelength of the device light (101), wherein a first set of first light generating devices (110) is configured to provide a first device light (111) having a first peak wavelength (λ1) in the blue wavelength range of 440 nm to 495 nm, a second set of second light generating devices (120) is configured to generate a second device light (121) having a second peak wavelength (λ2) in the UV wavelength range or in the violet wavelength range of 380 nm to 440 nm, and a third set of third light generating devices (130) is configured to generate a third device light (131) having a third peak wavelength (λ3) in the UV wavelength range or in the violet wavelength range of 380 nm to 440 nm; - the luminescent material (200) is arranged downstream of the array (40) of light generating devices (100); wherein the luminescent material (200) is arranged to convert at least a portion of the first device light (101) into luminescent material light (201); and wherein the luminescent material (200) is arranged to convert at least a portion of the second device light (121) and / or at least a portion of the third device light (131) into luminescent material light (201); The luminescent material (200) has different excitation intensities at different peak wavelengths (λ1, λ2, λ3); - the light generating devices (100) in the at least three sets (50) are configured in the array (40) according to an increase or decrease in the excitation intensity of the luminescent material (200) for different excitation intensities at different peak wavelengths; - wherein the array (40) comprises an edge array portion (41), the edge array portion comprising one or more rows (49), wherein the edge array portion (41) comprises a majority of light generating devices having a relatively lowest excitation intensity of the luminescent material (200) in the light generating devices (100) for a peak wavelength of device light (101) of the light generating devices; and - wherein the light generating device (100) and the luminescent material (200) are configured such that at least a portion of the second device light (121) and / or at least a portion of the third device light (131) is transmitted by the luminescent material (200).

2. The light generating system (1000) according to claim 1, wherein the second set of second light generating devices (120) is configured to generate second device light (121) having a second peak wavelength (λ2) in the violet wavelength range of 380nm to 440nm, and the third set of third light generating devices (130) is configured to generate third device light (131) having a third peak wavelength (λ3) in the UV wavelength range.

3. The light generating system (1000) according to any of the preceding claims, wherein the light generating device (100) and the luminescent material (200) are configured such that at least a portion of the first device light (111) is transmitted by the luminescent material (200).

4. The light generating system (1000) according to any one of the preceding claims, wherein the luminescent material (200) has a relatively highest excitation intensity for the first device light (111).

5. A light generating system (1000) according to any one of the preceding claims, wherein the array (40) comprises a core array portion (61) and a peripheral array portion (62), the core array portion comprising x1% of the total number of the light generating devices (100), the peripheral array portion comprising x2% of the total number of the light generating devices (100), wherein most of the light generating devices in which the luminescent material (200) in the light generating devices (100) has a relatively lower excitation intensity for a peak wavelength of the device light (101) of the light generating devices are arranged in the peripheral array portion (62), and wherein most of the light generating devices in which the luminescent material (200) in the light generating devices (100) has a relatively higher excitation intensity for a peak wavelength of the device light (101) of the light generating devices are arranged in the core array portion (61); wherein x1% is selected from the range of 5% to 95%, wherein x2% is selected from the range of 5% to 95%, and wherein x1%+x2%=100%.

6. The light generating system (1000) according to any of the preceding claims, wherein two sets of light generating devices are arranged in a symmetrical arrangement, a concentric arrangement or a linear arrangement. n2 A n1 B n2 Arrangement, wherein A refers to a first type of light generating device, such as a first light generating device, and n1≥1, and B refers to a second type of light generating device, such as a second light generating device, wherein n2≥1, and wherein in a specific embodiment, n1>n2.

7. The light generating system (1000) according to any one of the preceding claims, wherein: - the plurality of sets (150) of light generating devices (100) comprises at least n sets (50) of light generating devices (100), wherein n=4, wherein the light generating devices (100) comprises a fourth set of fourth light generating devices (140), the fourth set of fourth light generating devices being configured to generate fourth device light (141), the fourth device light having a fourth peak wavelength (λ4) in the UV wavelength range, or in the violet wavelength range, or in the visible wavelength range; The light generating devices (100) in the at least n sets (50) are configured for different excitation intensities at different peak wavelengths according to an increase or decrease in the excitation intensity of the luminescent material (200).

8. A light generating system (1000) according to any of the preceding claims, wherein (i) at least one of the at least three different sets (50) of the light generating devices (100) is configured to generate radiation having a peak wavelength within a wavelength range selected from the group consisting of UV-A radiation, UV-B radiation and near UV-C radiation, and (ii) at least another set of the at least three different sets (50) of the light generating devices (100) is configured to generate radiation having a peak wavelength within a violet wavelength range of 380 nm to 440 nm.

9. The light generating system (1000) according to any one of the preceding claims, wherein the luminescent material (200) comprises A3B5O 12 : Ce type luminescent material, wherein A includes one or more of Y, La, Gd, Tb and Lu, and wherein B includes one or more of Al, Ga, In and Sc; and wherein the system light is white light having a correlated color temperature in the range of 1800K to 6500K and a color rendering index of at least 80.

10. The light generating system (1000) according to any of the preceding claims 1 to 9, wherein all light generating devices (100) are configured in series.

11. The light generating system (1000) according to any of the preceding claims 1 to 9, wherein two or more of the at least two sets (50) of light generating devices (100) are individually controllable.

12. The light generating system (1000) according to any one of the preceding claims, comprising an LED filament (1100), wherein the LED filament (1100) comprises an array (40) of the light generating devices (100); wherein at least the second light generating device (120) and the third light generating device (130) are arranged at one end or both ends (1101, 1102) of the LED filament (1100).

13. The light generating system (1000) according to any one of the preceding claims, comprising a chip-on-board light generating device (1400), wherein the chip-on-board light generating device comprises an array (40) of the light generating devices (100); wherein the light generating system (1000) further comprises a light emitting layer (1500), wherein the light emitting layer comprises the light emitting material (200) configured downstream of the chip-on-board light generating device (1400); wherein the peripheral array portion (62) surrounds the core array portion (61); wherein The first light generating device (110) is configured in the core array part (61), and wherein the other light generating devices (120, 130, 140) are configured in the peripheral array part (62), wherein the core array part (61) includes a center (63), wherein the excitation intensity decreases with increasing distance from the center (63); and wherein x1% is selected from the range of 20% to 80%, and wherein x2% is selected from the range of 20% to 80%, wherein x1 and x2 are defined according to claim 5.

14. A light generating system (1000) according to any of the preceding claims, wherein the luminescent material (200) has a luminescent material surface (220), wherein a radiant flux of the luminescent material light (201) on 75% to 99% of the luminescent material surface (220) varies within a range of + / - 15% relative to an average radiant flux on the luminescent material surface (220).

15. A lighting device (1200) selected from the group consisting of a lamp (1), a luminaire (2) and an optical wireless communication device, the lighting device comprising the light generating system (1000) according to any one of the preceding claims.

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