3-channel chip on board with adjustable melanopic activity at constant color points

Abstract

The present invention provides a light-generating system 1000 configured to provide white light with an adjustable MDER value. In particular, the present invention provides a light-generating system 1000 configured to generate a system light 1001, the light-generating system 1000 comprising a first SSL light source string 100, a second SSL light source string 200 and a third SSL light source string 300, (A) the first SSL light source string 100 is configured to generate a first light 105 having a first color point and a first correlated color temperature CCT1, the first SSL light source string 100 comprises at least one first SSL light source 101 for generating purple and / or blue light and a first luminescent material 400, (B) the second SSL light source string 200 is configured to generate a first light 105 having a first color point and a first correlated color temperature CCT1, the first SSL light source string 100 comprises at least one first SSL light source 101 for generating purple and / or blue light and a first luminescent material 400, and (C) the second SSL light source string 200 comprises at least one first SSL light source 101 for generating purple and / or blue light and a first luminescent material 400, and (D) the second SSL light source string 200 comprises at least one first SSL light source 101 for generating purple and / or blue light and a first luminescent material 400, and (E) the second SSL light source string 200 comprises at least one first SSL light source 101 for generating purple and / or blue light and a first luminescent material 400, and (F) the second SSL light source string 200 comprises at least one first SSL light source 101 for generating purple and / or blue light and a first luminescent material 400, and (G) the second SSL light source string 200 comprises at least one first SSL light source 101 for generating purple and / or blue light and a first luminescent material 400, and (H) the second SSL light source string 200 (C) the third SSL light source string 300 is configured to generate a third light 305 having a third color point and a third correlated color temperature CCT3, the third SSL light source string 300 having at least one third SSL light source 301 for generating cyan light and a third luminescent material 400, (D) the first correlated color temperature is lower than the second correlated color temperature, and (E) the first correlated color temperature is lower than the third correlated color temperature.

Description

[Technical field]

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

[0002] The effect of light on circadian rhythm is known in the art. For example, WO2016145064 describes a device for influencing an individual's circadian outcome, the device including an eyewear article placed over one or both eyes of the individual, the eyewear article having one or more filter elements configured to controllably attenuate spectral components of light incident on the eyewear, the spectral components being within a circadian-active wavelength range, and the one or more filter elements being controlled based on information related to at least the individual's circadian outcome.

[0003] WO2021 / 204934A1 discloses a light generating system having a first string including a first and a second light generating device and a second string including a third light generating device. The first light generating device has (i) a first light source generating a first light source light having a first dominant wavelength selected from the range of 470 to 500 nm, and (ii) a first luminescent material converting a portion of the first light source light into a first luminescent material light. The light from the first light generating device has a first color point and a first correlated color temperature. The second and third light generating devices have (i) a blue light source and (ii) a luminescent material configured to convert at least a portion of the light from the solid-state light source into a luminescent material light. The light from the second light generating device is white light having a second color point and a second correlated color temperature. The light from the third light generating device is white light having a third color point and a third correlated color temperature. The color points of the first and second light-generating devices are comparable, and therefore the correlated color temperatures of the first and second light-generating devices are comparable. The first and second correlated color temperatures are at least 700 K greater than the third correlated color temperature. The first string provides a relatively cool white light and the second string provides a relatively warm white light.

[0004] US10750591B discloses a method for generating tunable white light with controllable circadian energy performance. The method uses multiple LED strings to generate light with a color point within the blue, yellow / green, red and cyan color ranges, each LED string being driven with a separately controllable drive current to adjust the generated light output. Different lighting modes utilizing different combinations of the multiple LED strings can be selected to adjust the generated white light. Summary of the Invention [Problem to be solved by the invention]

[0005] It is desirable to have a light producing system that allows for the provision of light with an adjustable Melanopic Daylight Efficacy Ratio (MDER) value. Furthermore, there appears to be a desire to provide light with a substantially fixed Correlated Color Temperature (CCT) but with a variable MDER. Furthermore, there appears to be a desire to provide light with a substantially (fixed) CCT but with a variable MDER, where the fixed CCT can be selected from a relatively wide temperature range. Furthermore, for certain applications, a high CRI may be desirable. However, prior art systems do not provide such functionality.

[0006] It is therefore an aspect of the present invention to provide an alternative light-generating system, which preferably also at least partially obviates one or more of the above disadvantages. The present invention may aim to eliminate or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. [Means for solving the problem]

[0007] In a first aspect, the present invention provides a light generating system ("system") configured to generate a system light. The light generating system may comprise a first SSL light source string, a second SSL light source string, and a third SSL light source string. In embodiments, the first SSL light source string may be configured to generate a first light having a first color point and a first correlated color temperature. In certain embodiments, the first SSL light source string may comprise at least one first SSL light source for generating purple and / or blue light, and a first luminescent material. In embodiments, the second SSL light source string may be configured to generate a second light having a second color point and a second correlated color temperature. In certain embodiments, the second SSL light source string may comprise at least one second SSL light source for generating purple and / or blue light, and a second luminescent material. Furthermore, in embodiments, the third SSL light source string may be configured to generate a third light having a third color point and a third correlated color temperature. In certain embodiments, the third SSL light source string may include at least one third SSL light source for generating cyan light and a third luminescent material. In particular embodiments, the first correlated color temperature may be lower than the second correlated color temperature. Furthermore, in certain embodiments, the first correlated color temperature may be lower than the third correlated color temperature.Therefore, in a particular embodiment, the present invention provides a light generating system configured to generate a system light, the light generating system comprising a first SSL light source string, a second SSL light source string and a third SSL light source string, (A) the first SSL light source string configured to generate a first light having a first color point and a first correlated color temperature, the first SSL light source string comprising at least one first SSL light source for generating purple and / or blue light and a first luminescent material, (B) the second SSL light source string configured to generate a second color point and a second correlated color temperature, the first SSL light source string comprising at least one first SSL light source for generating purple and / or blue light and a first luminescent material, the second ... (C) the third SSL light source string is configured to generate a third light having a third color point and a third correlated color temperature, the third SSL light source string having at least one third SSL light source for generating cyan light and a third luminescent material, (D) the first correlated color temperature is lower than the second correlated color temperature, and (E) the first correlated color temperature is lower than the third correlated color temperature.In an even more specific embodiment, the present invention relates to a light generating system configured to generate system light, the light generating system comprising a first SSL light source string, a second SSL light source string, and a third SSL light source string, (A) the first SSL light source string configured to generate light having a first color point, a first correlated color temperature, and a first MDER value, the first SSL light source string comprising at least one first SSL light source for generating purple and / or blue light and a first luminescent material, (B) the second SSL light source string configured to generate light having a second color point, a second correlated color temperature, and a second MDER value, the first SSL light source string comprising at least one first SSL light source for generating purple and / or blue light and a first luminescent material, and (C) the second SSL light source string configured to generate light having a second color point, a second correlated color temperature, and a second MDER value. (C) the third SSL light source string is configured to generate light having a third color point, a third correlated color temperature, and a third MDER value, the third SSL light source string having at least one third SSL light source for generating cyan light and a third luminescent material, (D) the first correlated color temperature is lower than the second correlated color temperature, and (E) the first correlated color temperature is lower than the third correlated color temperature.

[0008] In such a system, it is possible to provide light with a high color rendering index, with a variable correlated color temperature and a variable MDER. Moreover, in such a system, it is possible to vary the MDER value while keeping the color point essentially constant. Moreover, in such a system, it is possible to vary the MDER value while keeping the CCT essentially constant, while the fixed CCT may be selectable over a relatively wide temperature range.

[0009] As mentioned above, the light-generating system is in particular configured to generate a system light. The system light may comprise one or more of the first light, the second light and the third light. Other light sources are not excluded herein, but will not be described further (in detail) herein. In an embodiment, the system light may consist of one or more of the first light, the second light and the third light.

[0010] The term "system light" may refer inter alia to light escaping from the system. In embodiments, the system may have a light exit, such as an end window or (other) optical element, or an opening, through which the system light may escape outside the system. The system may have a housing that contains such a light exit. The housing may at least partially enclose one or more light sources and one or more (other) optical elements.

[0011] In particular, the light-generating system may comprise a first SSL light source string, a second SSL light source string and a third SSL light source string.

[0012] SSL light source strings, especially LED strings, are known in the art and are described, for example, in US9474111B2 or US8035315B2. As indicated by US8035315B2, the term "LED string" may refer to a group of one or more LEDs connected in series. The "head end" of an LED string is the end or portion of the LED string that receives a driving voltage / current, and the "tail end" of the LED string is the opposite end or portion of the LED string.

[0013] In an embodiment, the strings may be individually controllable. For this purpose, the system may comprise or be functionally coupled to a control system. For embodiments of the control system and / or for the operation mode, see also further below. Thus, in an embodiment, the light generating system may further comprise a control system configured to individually control the first SSL light source string, the second SSL light source string and the third SSL light source string. In particular, in this manner, the system light may be controlled. Thus, in an embodiment, the control system may be configured to control the system light by controlling the first light, the second light and the third light. In a particular embodiment, the control system may be configured to control one or more of the correlated color temperature, the color point and the melanopic daylight efficiency of the system light.

[0014] In an embodiment, the control system may be configured to control the system light in an operational mode such that the color point of the system light can be kept constant and the melanopic daylight efficiency can be changed. Thus, when changing the MDER, the color points at different MDER values ​​may be essentially the same. In a particular embodiment, the color or color point of the first type of light and the second type of light may be essentially the same if the respective color points of the first type of light and the second type of light differ by at most 0.03 for u' and / or at most 0.03 for v', even more particularly by at most 0.02 for u' and / or at most 0.02 for v'. In even more particular embodiments, the respective color points of the first type of light and the second type of light may differ by at most 0.01 for u' and / or at most 0.01 for v', where u' and v' are the color coordinates of light in the CIE 1976 UCS (Uniform Chromaticity) diagram. For further embodiments regarding MDER, see further below.

[0015] In embodiments, the control system may be configured to control the system light in an operational mode such that the CCT of the system light can be kept constant and the melanopic daylight efficiency can be varied. For example, the variation in CCT can be less than 5% of a predetermined CCT at which the MDER can be controlled, and / or can be within about + / - 300K of the predetermined CCT at which the MDER can be controlled.

[0016] Further, in an embodiment, the control system may be configured to control the system light in an operational mode such that the CRI of the system light remains above a predetermined threshold, such as at least 80, and in certain embodiments even at least 85, while allowing control of one or more of the CCT and the MDER.

[0017] Further, in an embodiment, the control system may be configured to control the system light in an operational mode such that R9 of the system light remains above a predetermined threshold of at least 0, and in certain embodiments even at least 20, such as even at least 40, while enabling control of one or more of, for example, the CCT and the MDER.

[0018] The solid state light sources (SSL light sources) of each string provide light that may be at least partially converted by the respective luminescent material during operation of the (respective) light source, which may result in a respective light including the luminescent material light of the respective string and, optionally, including unconverted light of the respective solid state light sources of the respective string.

[0019] The first SSL light source string may comprise a first light source and a first luminescent material, which may in particular be configured to convert at least a portion of the light of the first light source into the first luminescent material light. Thus, in an embodiment, the first SSL light source string may be configured to generate a first light having a first color point and a first correlated color temperature CCT1, the first SSL light source string comprising at least one first SSL light source for generating purple and / or blue light and a first luminescent material. The first luminescent material may in particular be configured to convert at least a portion of the light generated by the at least one first SSL light source.

[0020] The second SSL light source string may comprise a second light source and a second luminescent material, which may in particular be configured to convert at least a portion of the light of the second light source into the second luminescent material light. Thus, in an embodiment, the second SSL light source string may be configured to generate a second light having a second color point and a second correlated color temperature CCT2, the second SSL light source string comprising at least one second SSL light source for generating violet and / or blue light and a second luminescent material. The second luminescent material may in particular be configured to convert at least a portion of the light generated by the at least one second SSL light source.

[0021] The third SSL light source string may comprise a third light source and a third luminescent material, which may in particular be configured to convert at least a portion of the light of the third light source into a third luminescent material light. Thus, in an embodiment, the third SSL light source string is configured to generate a third light having a third color point and a third correlated color temperature CCT3, the third SSL light source string comprising at least one third SSL light source for generating cyan light and a third luminescent material. The third luminescent material may in particular be configured to convert at least a portion of the light generated by the at least one third SSL light source.

[0022] Thus, the first SSL light source string and the second SSL light source string may include one or more light sources configured to generate source light having blue and / or UV wavelengths, whereas the third SSL light source string may include one or more light sources configured to generate source light having a cyan wavelength.

[0023] Thus, one or more, in particular both, of (i) the first correlated color temperature is lower than the second correlated color temperature and (ii) the first correlated color temperature is lower than the third correlated color temperature may apply. In a particular embodiment, the first SSL light source string may be configured to generate a warm white light, and the second SSL light source string and the third SSL light source string may be configured to generate a cool white light.

[0024] In certain embodiments, CCT3>CCT2>CCT1.

[0025] In an embodiment, one or more, in particular all of (i) CCT3>3000K, (ii) CCT2>3000K and (iii) CCT1≦2700K may apply.

[0026] In an embodiment, one or more, in particular all, of (i) CCT3-CCT1 ≧1000K, (ii) CCT2-CCT1 ≧1000K, and (iii) CCT3-CCT2 ≧1000K may apply.

[0027] Furthermore, in more particular embodiments, one or more, in particular all, of (i) CCT3-CCT1 ≧2000K, (ii) CCT2-CCT1 ≧2000K, and (iii) CCT3-CCT2 ≧2000K may apply.

[0028] Furthermore, in more particular embodiments, one or more, in particular all of (i) CCT3>6000K, (ii) CCT2>5000K, and (iii) CCT1≦2500K may apply.

[0029] In certain embodiments, the first correlated color temperature may differ from the second correlated color temperature and the third correlated color temperature by at least 500K, and more particularly, in embodiments by at least 1000K, such as at least 1500K, such as at least about 2000K.

[0030] Thus, in an embodiment, the system light may be white light. In particular, the first light may be white light, the second light may be white light, and the third light may be white light. In this manner, essentially any combination or sole provision of the first light, the second light and the third light may result in a white system light. However, other embodiments are not excluded herein.

[0031] The term "white light" and similar terms in this specification are known to those skilled in the art. The white light may refer to light having a correlated color temperature (CCT) in the range of about 2000 to 7000 K, such as between about 1800 K and 20000 K, in particular between 2000 K and 20000 K, in particular between 2700 K and 20000 K, in particular in the range of about 2000 to 7000 K, such as in the range of 2200 to 6500 K, in particular in the range of 2700 to 6500 K, for general illumination. In embodiments, for example in backlight applications or for other applications, the correlated color temperature (CCT) may in particular be in the range of about 7000 to 20000 K. Furthermore, in embodiments, 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, and even more particularly within about 5 SDCM from the BBL.

[0032] Thus, in certain embodiments, the system light may be substantially white light with a correlated color temperature between 2200K and 6500K, preferably in the range of 2700-6500K, and more preferably in the range of 2200-5000K.

[0033] As noted above, in embodiments, the first color point, the second color point, and the third color point may lie on a straight line in a color diagram.

[0034] In particular, in an embodiment, all three color points of the first light, the second light and the third light may be essentially on a straight line in a color diagram, such as in particular the 1931 CIE x,y color diagram, or the CIE 1976 UCS u'v' diagram.

[0035] In an embodiment, the color points may be determined based on 10° color matching functions as described in International Standard ISO / CIE 11664-1, Colorimetry - Part 1: CIE Standard Colorimetric Observer, 2019-06, which is incorporated herein by reference.

[0036] The three color points do not have to be strictly on a straight line, for example in the color diagram 1931 CIE, but may be arranged at some distance apart. In general, however, this distance from the straight line may be 10 SDCM or less, such as 7 SDCM or less, in a particular embodiment 5 SDCM or less. In a particular embodiment, this distance from the straight line may be 3 SDCM or less. Thus, in a particular embodiment, selecting a straight line through two color points and intersecting the straight line in a range of 10 SDCM, in particular a range of 7 SDCM, more particularly a range of 4 SDCM around the other color point, may provide a set of color points according to the present invention.

[0037] Furthermore, at least two of the three color points may be subject to a non-overlapping color range of 5 SDCM, even 7 SDCM, even more particularly 10 SDCM around these two color points. In an embodiment, the first color point, the second color point and the third color point do not overlap within 10 SDCM (standard deviation of color matching), preferably do not overlap within 7 SDCM (standard deviation of color matching). As mentioned above, two of the three color points are from light with a CCT that may differ by at least 1000K, more particularly at least 1500K.

[0038] Thus, in certain embodiments, the first correlated color temperature may differ from the second correlated color temperature and the third correlated color temperature by at least 1000 K. Furthermore, all three color points determined based on 10° color matching functions may be located within 10 SDCM (standard deviation of color matching) of a substantially straight line in the color diagram, and at least two of the three color points within 10 SDCM (standard deviation of color matching) do not overlap. Thus, the respective 10 SDCM ranges of at least two of the three color points do not overlap.

[0039] The term "light source" may in principle relate to any light source known in the art. It may be a conventional (tungsten) light bulb, a low-pressure mercury lamp, a high-pressure mercury lamp, a fluorescent lamp, an LED (light emitting diode). In a particular embodiment, the light source comprises a solid-state LED light source (such as an LED or a laser diode (or "diode laser")). The term "light source" may also relate to a plurality of light sources, such as 2 to 2000 (solid-state) LED light sources. Thus, the term LED may also refer to a plurality of LEDs. Furthermore, the term "light source" may refer in embodiments to so-called chip-on-board (COB) light sources. The term "COB" or "CoB" may in particular refer to an LED chip in the form of a semiconductor chip that is not encapsulated or connected but is directly mounted on a substrate such as a PCB. Thus, several light-emitting semiconductor light sources may be arranged on the same substrate. In an embodiment, the COB is a multi-LED chip arranged together as a single lighting module.

[0040] The light source may have a light escape surface. For conventional light sources like light bulbs or fluorescent lamps, the light escape surface may be the outer surface of a glass or quartz envelope. In the case of an LED, the light escape surface may for example be the LED die or, if a resin is applied to the LED die, the outer surface of the resin. In principle, the light escape surface may also be the end of a fiber. The term escape surface particularly relates to the part of the light source where the light actually leaves or escapes from the light source. The light source is configured to provide a light beam. This light beam escapes from the light exit surface of the light source.

[0041] Similarly, the light-generating device may include a light escape surface, such as an end window.Further, similarly, the light-generating system may include a light escape surface, such as an end window.

[0042] The term "light source" may refer to a semiconductor light emitting device such as a light emitting diode (LED), a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSEL), an edge emitting laser, etc. The term "light source" may also refer to an organic light emitting diode (OLED), such as a passive matrix (PMOLED) or active matrix (AMOLED). In certain embodiments, the light source comprises a solid state light source (such as an LED or a laser diode). In embodiments, the light source comprises an LED (light emitting diode). The term "light source" or "solid state light source" may also refer to a superluminescent diode (SLED). In particular, the term "solid state light source" or "SSL light source" may refer to an LED.

[0043] The term LED can also refer to multiple LEDs.

[0044] The term "solid-state light source" or "SSL light source" may also refer to a plurality of (essentially identical (or different)) light sources, such as 2 to 2000 light sources. In an embodiment, the light source may further comprise one or more micro-optical elements (array of microlenses) downstream of the light source or downstream of the plurality of light sources (i.e. shared, for example, by the plurality of light sources). The SSL light source may comprise one or more of LEDs, superluminescent diodes, laser diodes, lasers or laser banks, etc. The term "SSL" refers in particular to solid-state light or solid-state lighting.

[0045] In embodiments, the light source may comprise an LED with on-chip optics, in embodiments, the light source comprises a single pixelated LED (with or without optics) (in embodiments providing on-chip beam steering).

[0046] In an embodiment, the light source may be configured to provide a primary radiation to be used as such, for example a blue light source such as a blue LED, or a green light source such as a green LED, and a red light source such as a red LED. Such LEDs, which may not include a luminescent material ("phosphor"), may be denoted direct color LEDs.

[0047] However, in other embodiments, the light source may be configured to provide a primary radiation, a portion of which is converted into a secondary radiation. The secondary radiation may be based on conversion by a luminescent material. The secondary radiation may therefore also be referred to as luminescent material radiation. The luminescent material may in embodiments be included by the light source, such as an LED with a luminescent material layer or dome that includes the luminescent material. Such an LED may be referred to as a phosphor converted LED or PC LED. In other embodiments, the luminescent material may be configured at some distance from the light source ("remote"), such as an LED with a luminescent material layer that is not in physical contact with the LED die. Thus, in certain embodiments, the light source may be a light source that, in operation, emits light at least at a wavelength selected from the range of 380 to 470 nm. However, other wavelengths may also be possible. This light may be partially used by the luminescent material.

[0048] The light source may be configured to generate a source light having, among other things, an optical axis (O), a (beam shape), and a spectral power distribution. The source light may, in embodiments, have one or more bands having a bandwidth as known for lasers.

[0049] The term "light source" may therefore refer to a light generating element itself, e.g. a solid-state light source, or may refer to a package of one or more of said light generating elements, e.g. a solid-state light source, and an element containing a luminescent material, and (other) optics, e.g. a lens, a collimator. A light conversion element ("conversion element" or "converter") may have an element containing a luminescent material. A solid-state light source itself, e.g. a blue LED, is a light source. A combination of a solid-state light source (e.g. a light generating element) and a light conversion element optically coupled to said solid-state light source, e.g. a blue LED and a light conversion element, may also be a light source (but may also be referred to as a light generating device). A white LED is therefore a light source (but may also be referred to as a (white) light generating device).

[0050] The term "light source" as used herein may refer to light sources including solid state light sources such as LEDs or laser diodes or superluminescent diodes.

[0051] The term "light source" may therefore also refer in embodiments to a light source that is (also) based on conversion of light, such as a light source in combination with a luminescence conversion material. The term "light source" may therefore also refer to a combination of an LED and a luminescent material configured to convert at least a portion of the radiation of the LED, or a combination of a (diode) laser and a luminescent material configured to convert at least a portion of the radiation of the (diode) laser.

[0052] In embodiments, the term "light source" may refer to a combination of a light source, such as an LED, and an optical filter that may change the spectral power distribution of the light generated by the light source. In particular, the term "light-generating device" may be used to refer to a light source and further optical components, such as optical filters and / or beam shaping elements.

[0053] The phrases "different light sources" or "multiple different light sources" and similar phrases may, in embodiments, refer to multiple solid-state light sources selected from at least two different bins. Similarly, the phrases "same light source" or "multiple identical light sources" and similar phrases may, in embodiments, refer to multiple solid-state light sources selected from the same bin.

[0054] The terms "solid-state light source" or "solid-state material light source" and similar terms may refer, among other things, to semiconductor light sources such as light emitting diodes (LEDs), diode lasers, or superluminescent diodes.

[0055] In an embodiment, the first SSL light source may be configured to provide first SSL light having a first dominant wavelength λ1d selected from the range of 440 to 470 nm, such as selected from the range of 450 to 460 nm, and / or having a first centroid wavelength λ1c selected from the range of 435 to 470 nm, such as selected from the range of 445 to 460 nm.

[0056] Alternatively, or in addition, in an embodiment, the second SSL light source is configured to provide second SSL light having a second dominant wavelength λ2d selected from the range of 425 to 470 nm, such as selected from the range of 435 to 460 nm, and / or having a second centroid wavelength λ2c selected from the range of 425 to 465 nm, such as selected from the range of 435 to 455 nm.

[0057] Alternatively, or in addition, in an embodiment, the third SSL light source is configured to provide third SSL light having a third dominant wavelength λ3d selected from the range of 470 to 520 nm, and / or having a third centroid wavelength λ3c selected from the range of 465 to 520 nm, such as selected from the range of 470 to 520 nm, such as selected from the range of 470 to 515 nm.

[0058] In particular, in the embodiment, (i) λ3d>λ2d and λ3d>λ1d, and / or (ii) λ3c>λ2c and λ3c>λ1c may apply. More particularly, in the embodiment, (i) λ3d-λ2d≧10 nm and λ3d-λ1d≧10 nm, and / or (ii) λ3c-λ2c≧10 nm and λ3c-λ1c≧10 nm may apply. Furthermore, in a particular embodiment, (i) λ3d-λ2d≧30 nm, and / or λ3c-λ2c≧30 nm may apply.

[0059] The term "centroid wavelength", also denoted λc, is known in the art and refers to the wavelength value where half of the light energy is at the shorter wavelength and half of the light energy is at the longer wavelength, the value being given in nanometers (nm). It is the wavelength that divides into two equal parts the integral of the spectral power distribution as expressed by the formula λc=Σλ×I(λ) / (ΣI(λ)), the summation being over the wavelength range of interest, where I(λ) is the spectral energy density (i.e., the integral of the product of wavelength and intensity over the emission band normalized to the integrated intensity). The centroid wavelength may be determined, for example, in operating conditions.

[0060] The term "dominant wavelength" may refer to the wavelength of a monochromatic light stimulus that corresponds to the color stimulus that is to be considered when additively mixed in appropriate proportions with a particular achromatic stimulus.

[0061] The invention may be described herein with respect to an embodiment in which the system comprises a chip-on-board device (see also above). Thus, in an embodiment, the light-generating system may comprise a chip-on-board device, the chip-on-board device comprising the first SSL light source string, the second SSL light source string, the third SSL light source string, the first luminescent material, the second luminescent material and the third luminescent material (and optionally the fourth luminescent material, etc.).

[0062] In particular, the first luminescent material may be arranged downstream substantially only of the first SSL light source, in particular, the second luminescent material may be arranged downstream substantially only of the second SSL light source, in particular, the third luminescent material may be arranged downstream substantially only of the third SSL light source.

[0063] However, as noted elsewhere, the first, second and third luminescent materials may be (substantially) the same, and thus luminescent materials may be arranged (i) downstream of one or more, in particular all, of the first SSL light source, (ii) downstream of one or more, in particular all, of the second SSL light source, and (iii) downstream of one or more, in particular all, of the third SSL light source.

[0064] In a further embodiment (see also below), the system may comprise a fourth luminescent material arranged downstream of one or more, in particular downstream of all, of the first SSL light source (but not downstream of the second and / or third SSL light source), and thus in an embodiment the chip-on-board device may (also) comprise the fourth luminescent material.

[0065] In certain embodiments, the chip-on-board device may be obtained by (i) providing a printed circuit board including the first SSL light source string, the second SSL light source string, and the third SSL light source string; (ii) providing the fourth luminescent material to the first SSL light source but not to the second SSL light source or the third SSL light source; and (iii) providing the first luminescent material, the second luminescent material, and the third luminescent material to the first SSL light source (and the fourth luminescent material), the second SSL light source, and the third SSL light source, respectively.

[0066] Therefore, the present invention also provides, in an aspect, a method comprising the steps of: (i) providing a printed circuit board including the first SSL light source string (particularly as defined herein), the second SSL light source string (particularly as defined herein) and the third SSL light source string (particularly as defined herein), (ii) providing the fourth luminescent material (particularly as defined herein) to the first SSL light source (particularly in the first string) but not to the second SSL light source (particularly in the second string) or the third SSL light source (particularly in the third string), and (iii) providing the first luminescent material (particularly as defined herein), the second luminescent material (particularly as defined herein) and the third luminescent material (particularly as defined herein) to the first SSL light source (and the fourth luminescent material), the second SSL light source and the third SSL light source, respectively. Thus, the CoB can already be provided with only two deposition steps instead of three. The latter may be especially true where the first, second and third luminescent materials may be the same.

[0067] The first, second and third luminescent materials may be substantially the same or different, particularly as noted above, the first, second and third luminescent materials may be substantially the same.

[0068] The light generating system may be a Chip-on-Board (CoB) type system. The luminescent material at least partially converts light from the SSL light source.

[0069] In an embodiment, the first color point, the second color point, and the third color point lie on a substantially straight (single) line in a color diagram. The color points may be expressed as u' and v' color coordinates of light in a CIE 1976 UCS (Uniform Chromaticity) diagram. In another example, the color points may be expressed as coordinates in a CIE 1931 color space chromaticity diagram.

[0070] The term "luminescent material" refers in particular to a material capable of converting a first radiation, in particular one or more of violet, cyan and blue radiation, into a second radiation. Generally, the first radiation and the second radiation have different spectral power distributions. Therefore, instead of the term "luminescent material", the term "luminescence converter" or "converter" may be applied. Generally, the second radiation has a spectral power distribution at a wavelength greater than the first radiation, which is the case of so-called down-conversion. However, in certain embodiments, the second radiation has a spectral power distribution with an intensity at a wavelength less than the first radiation, which is the case of so-called up-conversion. In embodiments, the "luminescent material" may refer in particular to a material capable of converting radiation, for example into visible light and / or infrared light. For example, in embodiments, the luminescent material may be capable of converting one or more of blue, violet and cyan radiation into visible light.

[0071] Thus, the luminescent material emits radiation when excited by radiation. Typically, the luminescent material is a downconverter, i.e., the smaller wavelength radiation is converted to a larger wavelength (λ ex <λ em ), in certain embodiments, the luminescent material may comprise an upconverter luminescent material, i.e., the larger wavelength radiation is converted to radiation having a smaller wavelength (λ ex >λ em ) is converted into radiation with a

[0072] In embodiments, the term "luminescence" may refer to phosphorescence. In embodiments, the term "luminescence" may refer to fluorescence. Instead of the term "luminescence", the term "emission" may be applied. Thus, the terms "first radiation" and "second radiation" may refer to excitation radiation and luminescence (radiation), respectively. Similarly, the term "luminescent material" may refer to phosphorescence and / or fluorescence, in embodiments.

[0073] The term "luminescent material" may refer to a number of different luminescent materials. Examples of possible luminescent materials are provided below. Thus, the term "luminescent material" may, in certain embodiments, refer to a luminescent material composition.

[0074] In an embodiment, the luminescent material is selected from garnets and nitrides, in particular doped with trivalent cerium or divalent europium, respectively. The term "nitride" may also refer to oxynitrides or nitridosilicates, etc. Alternatively or in addition, the luminescent material may be selected from silicates, in particular doped with divalent europium.

[0075] In certain embodiments, the luminescent material is ABO. 12:Ce type luminescent materials, where A in embodiments comprises one or more of Y, La, Gd, Tb and Lu, in particular (at least) one or more of Y, Gd, Tb and Lu, and B in embodiments comprises one or more of Al, Ga, In and Sc. In particular, A may comprise one or more of Y, Gd and Lu, in particular one or more of Y and Lu. In particular, B may comprise at least Al, such as one or more of Al and Ga, more in particular essentially only Al. Thus, a particularly suitable luminescent material is a cerium comprising garnet material. Garnet embodiments are in particular of the type A3B5O 12 The garnet includes A at least yttrium or lutetium and B at least aluminum. Such garnets may be doped with cerium (Ce), praseodymium (Pr) or a combination of cerium and praseodymium, but in particular with Ce. In particular, B includes aluminum (Al), but B may also partially include gallium (Ga) and / or scandium (Sc) and / or indium (In), in particular up to about 20% of Al, more in particular up to about 10% of Al (i.e., B ions essentially consist of 90 mol % or more of Al and 10 mol % or less of one or more of Ga, Sc and In). B may in particular include up to about 10% of gallium. In another variant, B and O may be at least partially replaced by Si and N. The element A may be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb), and lutetium (Lu). Furthermore, Gd and / or Tb are particularly present in an amount up to about 20% of A. In a particular embodiment, the garnet luminescent material is selected from the group consisting of (Y 1-x Lu x )3B5O 12 :Ce, where x is 0 or more and 1 or less. The term ":Ce" indicates that some of the metal ions in the luminescent material (i.e., in garnets, some of the "A" ions) are replaced with Ce. For example, (Y 1-x Lux )3Al5O 12 : In the case of Ce, part of Y and / or Lu is replaced by Ce. This is known to those skilled in the art. Ce generally replaces A by 10% or less, and generally, the Ce concentration is in the range of 0.1 to 4%, particularly 0.1 to 2% (relative to A). Assuming 1% of Ce and 10% of Y, the completely correct formula would be (Y 0.1 Lu 0.89 Ce 0.01 )3Al5O 12 This can be the case. Ce in garnet is substantially in the trivalent state or only in the trivalent state, as is known to those skilled in the art.

[0076] In an embodiment, the luminescence material (therefore) contains A3B5O 12 and in a specific embodiment, up to 10% of B - O can be replaced by Si - N.

[0077] In a specific embodiment, the luminescence material contains (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O 12 where x1 + x2 + x3 = 1, x3 > 0, 0 < x2 + x3 ≤ 0.2, y1 + y2 = 1, 0 ≤ y2 ≤ 0.2, A' contains one or more elements selected from the group consisting of lanthanides, and B' contains one or more elements selected from the group consisting of Ga, In, and Sc. In an embodiment, x3 is selected from the range of 0.001 to 0.1. In the present invention, in particular, x1 > 0, such as at least 0.8, such as x1 > 0.2. Garnet with Y can provide an appropriate spectral power distribution.

[0078] In certain embodiments, up to 10% of the B-O can be replaced with Si-N. Here, B in B-O refers to one or more of Al, Ga, In, and Sc (and O refers to oxygen), and in certain embodiments, B-O may refer to Al-O. As noted above, in certain embodiments, x3 can be selected from the range of 0.001 to 0.04. In particular, such luminescent materials have an appropriate spectral distribution (see below), relatively high efficiency, relatively high thermal stability, and can enable a high CRI (in combination with the source light). Thus, in certain embodiments, A can be selected from the group consisting of Lu and Gd. Alternatively, or in addition, B can include Ga. Thus, in an embodiment, the luminescent material is (Y x1-x2-x3 (Lu,Gd) x2 Ce x3 )3(Al y1-y2 Ga y2 )5O 12 and may include Lu and / or Gd. Even more particularly, x3 is selected from the range of 0.001 to 0.1, 0 < x2 + x3 ≤ 0.1, and 0 ≤ y2 ≤ 0.1. Further, in certain embodiments, up to 1% of the B-O can be replaced with Si-N. Here, the percentages refer to moles (as is known in the art), and see, for example, EP3149108. In still other particular embodiments, the luminescent material is (Y x1-x3 Ce x3 )3Al5O 12 where x1 + x3 = 1, 0 < x3 ≤ 0.2, and is, for example, from 0.001 to 0.1.

[0079] In certain embodiments, one or more luminescent materials may be selected from the type of garnet containing cerium. In still other particular embodiments, one of the solid light sources is (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O 12It may include a single type of luminescence material such as etc. Thus, in certain embodiments, the light source may have a luminescence material, and at least 85% by weight, even more particularly at least about 90% by weight, for example even more particularly at least about 95% by weight of the luminescence material is (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O 12 . Here, A' includes one or more elements selected from the group consisting of lanthanides, B' includes one or more elements selected from the group consisting of Ga, In, and Sc, x1 + x2 + x3 = 1, x3 > 0, 0 < x2 + x3 ≤ 0.2, y1 + y2 = 1, and 0 ≤ y2 ≤ 0.2. In particular, x3 is selected from the range of 0.001 to 0.1. It should be noted that in an embodiment, x2 = 0. Alternatively, or in addition, in an embodiment, y2 = 0.

[0080] In certain embodiments, A may particularly include at least Y, and B may particularly include at least Al.

[0081] Alternatively, or in addition, the luminescence material may include a luminescence material of the A3Si6N 11 :Ce 3+ type, and A includes one or more of Y, La, Gd, Tb, and Lu, such as one or more of La and Y in an embodiment.

[0082] In an embodiment, the luminescence material may, alternatively, or in addition, be MS:Eu 2+ and / or M2Si5N8:Eu 2+ and / or MAlSiN3:Eu 2+ and / or Ca2AlSi3O2N5:Eu 2+and the like, where M comprises one or more of Ba, Sr and Ca, and in particular embodiments at least Sr. Thus, in embodiments, the luminescent material may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu and (Ba,Sr,Ca)2Si5N8:Eu. In these compounds, europium (Eu) is substantially or exclusively divalent and replaces one or more of the divalent cations indicated. Generally, Eu is not present in an amount greater than 10% of the cations, and the presence of Eu is particularly in the range of about 0.5 to 10%, more particularly in the range of about 0.5 to 5%, relative to the cation it replaces. The term ":Eu" refers to the presence of a portion of the metal ions that are not Eu (in these examples Eu 2+ For example, assuming 2% Eu in CaAlSiN3:Eu, the correct formula is (Ca 0.98 EU 0.02 )AlSiN3. Divalent europium generally replaces divalent cations, such as the divalent alkaline earth cations mentioned above, in particular Ca, Sr or Ba. The material (Ba,Sr,Ca)S:Eu may also be denoted MS:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), in particular M includes calcium or strontium, or calcium and strontium, more particularly calcium, in this compound, where Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca). Furthermore, the material (Ba,Sr,Ca)2Si5N8:Eu may also be denoted M2Si5N8:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), in particular M includes Sr and / or Ba in this compound. In a further particular embodiment, M consists of Sr and / or Ba (not taking into account the presence of Eu), Ba 1.5 Sr 0.5In particular, it consists of 50-100%, more particularly 50-90% Ba and 50-0%, particularly 50-10% Sr, such as Si5N8:Eu (i.e. 75% Ba; 25% Sr), where Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca). Similarly, the material (Ba,Sr,Ca)AlSiN3:Eu may also be denoted as MAlSiN3:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), in particular M includes calcium or strontium, or calcium and strontium, more particularly calcium, in this compound. In particular, Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca). The Eu in the above luminescent materials is substantially or exclusively in a divalent state, as known to those skilled in the art.

[0083] In embodiments, the red luminescent material may include one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu, and (Ba,Sr,Ca)2Si5N8:Eu. In these compounds, europium (Eu) is substantially or exclusively divalent and replaces one or more of the divalent cations shown. Generally, Eu is not present in an amount greater than 10% of the cations, and the presence of Eu is particularly in the range of about 0.5 to 10%, more particularly in the range of about 0.5 to 5%, relative to the cation it replaces. The term ":Eu" indicates that a portion of the metal ions is Eu (in these examples Eu 2+ For example, assuming 2% Eu in CaAlSiN3:Eu, the correct formula is (Ca 0.98 EU 0.02 )AlSiN3. Divalent europium generally replaces a divalent cation, such as the divalent alkaline earth cations mentioned above, particularly Ca, Sr or Ba.

[0084] The material (Ba,Sr,Ca)S:Eu may also be denoted MS:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), in particular M comprises calcium or strontium, or calcium and strontium, more particularly calcium, in this compound, where Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca). Furthermore, the material (Ba,Sr,Ca)2Si5N8:Eu may also be denoted M2Si5N8:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), in particular M comprises Sr and / or Ba, in this compound. In further particular embodiments, M comprises Sr and / or Ba (not taking into account the presence of Eu), where Ba 1.5 Sr 0.5 In particular, it consists of 50-100%, more particularly 50-90% Ba and 50-0%, particularly 50-10% Sr, such as Si5N8:Eu (i.e. 75% Ba; 25% Sr), where Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca). Similarly, the material (Ba,Sr,Ca)AlSiN3:Eu may also be denoted as MAlSiN3:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), in particular M includes calcium or strontium, or calcium and strontium, more particularly calcium, in this compound. In particular, Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca). The Eu in the above luminescent materials is substantially or exclusively in a divalent state, as known to those skilled in the art.

[0085] The blue luminescent material is YSO (Y2SiO5:Ce 3+ ), or a similar compound, or BAM (BaMgAl 10 O 17 :EU 2+), or a similar compound.

[0086] The term "luminescent material" in this specification relates in particular to inorganic luminescent materials. Instead of the term "luminescent material", the term "phosphor" may also be applied. These terms are known to those skilled in the art.

[0087] Alternatively or in addition, other luminescent materials may be applied. For example, quantum dots and / or organic dyes may be applied, optionally embedded in a transparent matrix, for example a polymer such as PMMA or polysiloxane. Quantum dots are small crystals of semiconductor materials, typically with a width or diameter of only a few nanometers. When excited by incident light, quantum dots emit light with a color determined by the size and material of the crystal. Thus, by adapting the size of the dot, light of a specific color can be generated. The most known quantum dots that emit in the visible range are based on cadmium selenide (CdSe) with shells such as cadmium sulfide (CdS) and zinc sulfide (ZnS). Cadmium-free quantum dots such as indium phosphide (InP) and copper indium sulfide (CuInS2) and / or silver indium sulfide (AgInS2) can also be used. Quantum dots exhibit very narrow emission bands, and therefore they exhibit saturated colors. Moreover, the emission color can be easily adjusted by adapting the size of the quantum dots. Any type of quantum dot known in the art can be used in the present invention. However, for reasons of safety and concerns regarding the environment, it may be preferable 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 may be used. "Quantum confinement structures" are to be understood in the context of this application as, for example, quantum wells, quantum dots, quantum rods, tripods, tetrapods, or nanowires. Organic phosphors can also be used. Examples of suitable organic phosphor materials are organic luminescent materials based on perylene derivatives, such as the compounds sold by BASF under the name Lumogen®. Examples of suitable compounds include, but are not limited to, Lumogen® Red F305, Lumogen® Orange F240, Lumogen® Yellow F083, and Lumogen® F170.

[0088] Different luminescent materials may have different spectral power distributions of their respective luminescent material light. Alternatively, or in addition, such different luminescent materials may have, among other things, different color points (or dominant wavelengths).

[0089] As mentioned above, other luminescent materials may be possible. Thus, in certain embodiments, the luminescent material is selected from the group of divalent europium-containing nitrides, divalent europium-containing oxynitrides, divalent europium-containing silicates, cerium-containing garnets, and quantum structures. The quantum structures may include, for example, quantum dots or quantum rods (or other quantum-type particles) (see above). The quantum structures may also include quantum wells. The quantum structures may also include photonic crystals.

[0090] In certain embodiments, the first luminescent material is ABO 12 Alternatively or additionally, the second luminescent material may also be of the type ABO:Ce, where A comprises one or more of Y, La, Gd, Tb and Lu, and B comprises one or more of Al, Ga, In and Sc. 12 :Ce type luminescent materials, where A comprises one or more of Y, La, Gd, Tb and Lu and B comprises one or more of Al, Ga, In and Sc. However, the first luminescent material and (optionally) the second luminescent material may in particular be selected such that, upon irradiation with the source light, the respective luminescent material light (of the first luminescent material and the second luminescent material) has different spectral power distributions.

[0091] The luminescent material may be selected to obtain an emission band with a full width at half maximum (of the luminescent material light) of at least 40 nm, such as at least 50 nm. For example, the luminescent material may be selected to obtain an emission band with a full width at half maximum of at least 60 nm. This may be the case, for example, for a garnet luminescent material containing trivalent cerium (as described herein). Thus, in particular, the luminescent material may include a broadband emitter. The luminescent material may also have a plurality of broadband emitters. In particular, when two or more luminescent materials are applied to convert at least a portion of the first device light and / or at least a portion of the second device light, at least two of the two or more luminescent materials may be configured to provide a respective luminescent material light having an emission band with a full width at half maximum (of the luminescent material light) of at least 40 nm, such as at least 50 nm.

[0092] In embodiments, the first luminescent material, the second luminescent material and the third luminescent material may be substantially the same, more particularly the same. In such embodiments, a single luminescent material may be used to represent the first luminescent material, the second luminescent material and the third luminescent material (but not the fourth luminescent material). Examples of such luminescent materials include (e.g., Lu 1-x-y-a-b Y x Gd y )3(Al 1-z-u Ga z S u )5O 12-u N u :Ce a Pr b Ce-doped garnets (e.g., Sr 1-x Ba x Eu-doped silicates, such as SCASN:(Ca 1-x-y Sr y )AlSiN3:Eu x 2+including Eu-doped nitrides such as, or combinations of two or more of them. In particular, the first luminescence material may have a combination of (i) a green and / or yellow-emitting luminescence material, in particular at least a green-emitting luminescence material, and (ii) a red-emitting luminescence material.

[0093] (Lu 1-x-y-a-b Y x Gd y )3Al5O 12 N:Ce a Pr b Regarding this, it should be noted that 0 < a ≤ 0.2, in particular 0.005 ≤ a ≤ 0.1, 0 ≤ b ≤ 0.2, in particular b < 0.00001, etc., 0 ≤ a ≤ 0.05, 0 ≤ x < 1, 0 ≤ y < 1, 0 ≤ x + y + b < 1, and 0 ≤ x + y + a + b ≤ 1. In an embodiment, a part of Al - O may be replaced by Si - N.

[0094] (Sr 1-x Ba x )2SiO4:Eu), etc., regarding M2SiO4:Eu, it should be noted that 0 ≤ x ≤ 1 (can be applied). Furthermore, regarding Eu in these compounds, europium is in a divalent state and can be available in the range of 0.5 to 10 at% with respect to M (in this example, Sr 1-x Ba x ).

[0095] Ca 1-x-y Sr y )AlSiN3:Eu x 2+ Regarding MAlSiN3:Eu such as, regarding Eu in these compounds, europium is in a divalent state and can be available in the range of 0.5 to 10 at% with respect to M (in this example, Ca 1-x-y Sr y ). Furthermore, Ca 1-x-y Sr y )AlSiN3:Eu x 2+Regarding this, it should be noted that 0 < x + y ≤ 1 and 0 ≤ y < 1 (may be applicable).

[0096] Therefore, in an embodiment, the light generation system may further include a fourth luminescent material different from the first luminescent material, the second luminescent material, and the third luminescent material. The fourth luminescent material is configured downstream of the at least one first SSL light source and may not be configured downstream of the at least one second SSL light source and the at least one third SSL light source.

[0097] Therefore, in an embodiment, the first SSL light source string may include a first light source, as well as the first luminescent material and the fourth luminescent material. The first luminescent material and the fourth luminescent material may be configured to convert at least a part of the light of the first light source into first luminescent material light and fourth luminescent material light. Therefore, in an embodiment, the first SSL light source string may be configured to generate first light having a first color point and a first correlated color temperature CCT1. The first SSL light source string includes at least one first SSL light source for generating purple and / or blue light, the first luminescent material, and the fourth luminescent material. Therefore, the first light may include fourth luminescent material light and first luminescent material light, and optionally may include all three contributions of the light of the first light source.

[0098] In certain embodiments, the first luminescent material, the second luminescent material, and the third luminescent material may be configured downstream of all of the at least one first SSL light source, the at least one second SSL light source, and the at least one third SSL light source. Moreover, in particular embodiments, there are no other luminescent materials configured downstream of the at least one second SSL light source and the at least one third SSL light source. As noted above, the first luminescent material, the second luminescent material, and the third luminescent material may be essentially the same in embodiments.

[0099] In particular, the first SSL light source string may further comprise a fourth luminescent material different from the first, second and third luminescent materials. In particular embodiments, the fourth luminescent material may be an orange and / or red luminescent material. In embodiments, the fourth luminescent material may comprise Ce-doped garnet (see also above), Eu-doped silicate (see also above), Eu-doped nitride (see also above), or a combination of two or more thereof.

[0100] In an embodiment, the first luminescent material, the second luminescent material and the third luminescent material are essentially the same and comprise a first combination of at least two luminescent materials, at least one configured to generate red light and at least one configured to generate green and / or yellow light. This combination of luminescent materials may therefore be arranged downstream of all of the at least one first SSL light source, the at least one second SSL light source and the at least one third SSL light source. Furthermore, the fourth luminescent material comprises a second combination of at least two luminescent materials, at least one configured to generate red light and at least one configured to generate green and / or yellow light. In particular, the fourth luminescent material may be arranged downstream of the at least one first SSL light source (and not arranged downstream of the at least one second SSL light source and / or not arranged downstream of the at least one third SSL light source). Thus, the fourth luminescent material may be arranged downstream of one or more, in particular all, of the first SSL light source (and not downstream of the second and / or third SSL light source). In particular, the spectral power distribution of the fourth luminescent material light may be different from the spectral power distribution of the first luminescent material light, the spectral power distribution of the second luminescent material light and the spectral power distribution of the third luminescent material light. Thus, in an embodiment, the first combination of luminescent materials is different from the second combination of luminescent materials. The difference lies in the relative amounts and / or chemical composition of the luminescent materials, in particular at least the latter. The term "combination of luminescent materials" may in particular refer to a mixture of luminescent materials.

[0101] In certain embodiments, the second SSL light source string may further comprise a fifth luminescent material.

[0102] Thus, in an embodiment, the second SSL light source string may comprise a second light source and the second and fifth luminescent materials, which may in particular be configured to convert at least a portion of the light of the second light source into second and fifth luminescent material light. Thus, in an embodiment, the second SSL light source string may be configured to generate a second light having a second color point and a second correlated color temperature CCT2, the second SSL light source string comprising at least one second SSL light source for generating purple and / or blue light, a second luminescent material and the fifth luminescent material. Thus, the second light may comprise the fifth luminescent material light and the second luminescent material light, and optionally the light of the second light source, in particular all three contributions. In embodiments, the fifth luminescent material may comprise a Ce-doped garnet (see also above), a Eu-doped silicate (see also above), a Eu-doped nitride (see also above), or a combination of two or more thereof.

[0103] Furthermore, the fifth luminescent material comprises a second combination of at least two luminescent materials, at least one configured to generate red light and at least one configured to generate green and / or yellow light. In particular, the fifth luminescent material may be arranged downstream of the at least one second SSL light source (and not arranged downstream of the at least one first SSL light source and / or not arranged downstream of the at least one third SSL light source). In particular, a spectral power distribution of the fifth luminescent material light may be different from a spectral power distribution of the first luminescent material light, a spectral power distribution of the second luminescent material light, a spectral power distribution of the third luminescent material light, and a spectral power distribution of the fourth luminescent material light.

[0104] As described above, the present invention enables control of the MDER value, such as controlling the MDER value while keeping the color point of the system light essentially constant and / or while keeping the CCT of the system light essentially constant (among other things).

[0105] The melanopic daylight efficacy ratio, abbreviated as "melanopic DER" or "MDER", can be used to indicate the melanopsin active radiation in a luminous flux. In other words, the melanopic DER is the ratio of the melanopic efficacy of the luminous radiation (of a light source) to the melanopic efficacy of the luminous radiation of daylight (D65). In the formula:

number

number

number

number

[0106] In embodiments, the first light may have a first melanopic daylight efficiency rating (MDER), the second light may have a second melanopic daylight efficiency rating (MDER), and the third light may have a third melanopic daylight efficiency rating (MDER), and in certain embodiments, the second MDER value may be lower than the third MDER value.

[0107] In embodiments, the first MDER may be selected from the range of 0.065 to 1.02, such as 0.07 to 1.015. Alternatively or additionally, the second MDER may be selected from the range of 0.25 to 1.7, such as 0.35 to 1.6. Further alternatively or additionally, the third MDER may be selected from the range of 1.20 to 2.4, such as 1.30 to 2.25.

[0108] In embodiments, the third MDER value may be greater than both the first MDER value and the second MDER value. In particular, in embodiments, at least two of the first MDER value, the second MDER value and the third MDER value may differ from each other by at least 0.1.

[0109] The terms "upstream" and "downstream" relate to the positioning of an item or feature relative to the propagation of light from a light generating means (here, in particular the light source), such that relative to a first position in the light beam from the light generating means, a second position in the light beam closer to the light generating means is "upstream" and a third position in the light beam further away from the light generating means is "downstream".

[0110] The term "control" and similar terms refer in particular to at least determining the behavior of an element or supervising the operation of an element. Thus, in this specification, the term "control" and similar terms may refer to imposing a behavior on the element (determining the behavior of an element or supervising the operation of an element), such as, for example, measuring, indicating, activating, opening, shifting, changing temperature, etc. The term "control" and similar terms may further include monitoring as well. Thus, the term "control" and similar terms may include imposing a behavior on an element and may include imposing a behavior on an element and monitoring the element. The control of the element may be performed by a control system, which may be denoted as a "controller". Thus, the control system and the element may be functionally coupled, at least temporarily or permanently. The element may comprise the control system. In an embodiment, the control system and the element may not be physically coupled. The control may be performed via wired and / or wireless control. The term "control system" may also refer to a number of different control systems, particularly those that are functionally coupled, for example one control system of the number of different control systems may be a master control system and one or more other control systems may be slave control systems. A control system may have a user interface or may be functionally coupled to a user interface.

[0111] The control system may also be configured to receive and execute instructions from a remote control device. In an embodiment, the control system may be controlled via an app on a device, such as a smartphone or portable device, such as an iPhone, tablet, etc. Thus, the device is not necessarily coupled to the lighting system, but may be (temporarily) functionally coupled to the lighting system.

[0112] Thus, in an embodiment, the control system may (also) be configured to be controlled by an app on a remote device. In such an embodiment, the control system of the lighting system may be a slave control system or may control in slave mode. For example, the lighting systems may be identifiable by a code, in particular a unique code for each lighting system. The control system of the lighting system may be configured to be controlled by an external control system that accesses the lighting system based on knowledge entered by a user interface comprising an optical sensor (e.g. a QR code reader) of the (unique) code. The lighting system may also have means for communicating with other systems or devices, such as based on Bluetooth, WIFI, LiFi, ZigBee, BLE or WiMAX, or another wireless technology.

[0113] The system, or apparatus, or device may perform an operation in a "mode" or "operational mode" or "operable mode" or "mode of operation" or "control mode". Similarly, in a method, an operation, or a stage, or a step may be performed in a "mode" or "operational mode" or "operable mode" or "mode of operation" or "control mode". The term "mode" may also be indicated as a "control mode". This does not exclude that the system, or apparatus, or device may also be adapted to provide another control mode, or multiple other control modes. Similarly, this may not exclude that one or more other modes may be performed before and / or after performing the mode. The term "operational mode" and similar terms may (in embodiments) refer to one or more operation modes.

[0114] However, in embodiments, a control system may be available that is adapted to provide at least said control mode. If other modes are available, the selection of such modes may in particular be performed via a user interface, although other options may also be possible, such as performing the mode depending on a sensor signal or a (time) scheme. The operating mode may also refer in embodiments to a system, or apparatus, or device that can only operate in a single operating mode (i.e. "on", without further adjustability).

[0115] Thus, in an embodiment, the control system may be dependent on one or more of a user interface input signal, a sensor signal (of a sensor), and a timer, where the term "timer" may refer to a clock and / or a predefined timing scheme.

[0116] As mentioned above, the luminescent material may partially convert the source light, either in a transmission mode or in a reflection mode, and the unconverted source light may in embodiments propagate together with the first luminescent material light.

[0117] The terms "visible", "visible light" or "visible emission" and similar terms refer to light having one or more wavelengths in the range of about 380-780 nm. In this specification, UV may refer specifically to wavelengths selected from the range of 200-380 nm. In this specification, the terms "light" and "radiation" are used interchangeably, unless it is clear from the context that the term "light" refers only to visible light. Thus, the terms "light" and "radiation" may refer to UV radiation, visible light, and IR radiation. In certain embodiments, particularly for lighting applications, the terms "light" and "radiation" refer to (at least) visible light. The term "violet light" or "violet emission" particularly refers to light having a wavelength in the range of about 380-440 nm. The term "blue light" or "blue emission" particularly refers to light having a wavelength in the range of about 440-495 nm (including some purple and cyan hues). The term "green light" or "green emission" particularly refers to light having a wavelength in the range of about 495-570 nm. The term "yellow light" or "yellow emission" particularly relates to light having a wavelength in the range of about 570 to 590 nm. The term "orange light" or "orange emission" particularly relates to light having a wavelength in the range of about 590 to 620 nm. The term "red light" or "red emission" particularly relates to light having a wavelength in the range of about 620 to 780 nm. The term "cyan" may refer to one or more wavelengths selected from the range of about 470 to 520 nm. The term "amber" may refer to one or more wavelengths selected from the range of about 585 to 605 nm, such as about 590 to 600 nm.

[0118] The term "white light" in this specification is known to those skilled in the art. Said white light particularly relates to light with a correlated color temperature (CCT) between about 1800K and 20000K, such as between 2000K and 20000K, particularly between 2700K and 20000K, particularly in the range of about 2700 to 6500K for general illumination. In an embodiment, for backlight applications, said correlated color temperature (CCT) may particularly be in the range of about 7000 to 20000K. Furthermore, in an embodiment, said correlated color temperature (CCT) is particularly within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), particularly within about 10 SDCM from the BBL, even more particularly within about 5 SDCM from the BBL.

[0119] In particular, in an embodiment, the control system may be configured to control one or more of the color rendering index, the correlated color temperature and the MDER value of the system light.

[0120] The light generating system may be part of or used in, for example, an office lighting system, a home application system, a shop lighting system, a domestic lighting system, an accent lighting system, a spot lighting system, a theatre lighting system, a fiber optic application system, a projection system, a self-lit display system, a pixelated display system, a segmented display system, a warning sign system, a medical lighting application system, an indicator sign system, a decorative lighting system, a portable system, an automotive application, an (outdoor) road lighting system, an urban lighting system, a greenhouse lighting system, a horticultural lighting, digital projection, or an LCD backlight. The light generating system (or the luminaire) may be part of or used in, for example, an optical communication system or a disinfection system.

[0121] In yet another aspect, the present invention also provides a lamp or luminaire comprising a light generation system as defined herein. The luminaire may further comprise a housing, optical elements, louvers, etc. The lamp or luminaire may further comprise a housing enclosing the light generation system. The lamp or luminaire may comprise a light window or housing opening in the housing, through which the system light may escape from the housing. In yet another aspect, the present invention also provides a projection device comprising a light generation system as defined herein. In particular, a projection device or "projector" or "image projector" may be an optical device that projects an image (or a moving image) onto a surface, such as a projection screen. The projection device may comprise one or more light generation systems as described herein. Thus, in one aspect, the present invention also provides an illumination device selected from the group of lamps, luminaires and projector devices, comprising a light generation system as defined herein. The illumination device may comprise a housing configured to accommodate, or a carrier configured to support, one or more elements of the light generation system. [Brief description of the drawings]

[0122] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, in which: [Figure 1A] 1 illustrates a schematic representation of an embodiment of a light-generating system according to the present invention; [Figure 1B] 1 illustrates a schematic representation of an embodiment of a light-generating system according to the present invention; [Diagram 2] 1 illustrates generally embodiments and aspects according to the present invention; [Diagram 3] Several embodiments are shown. [Figure 4a] The excitation and emission spectra of some suitable fluorophores are shown. [Figure 4b]4 illustrates several embodiments of a spectral power distribution. [Diagram 5] Some application examples are illustrated diagrammatically.

[0123] The schematic drawings are not necessarily to scale. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0124] A conventional chip-on-board device (COB) is a light source with a dense package of (blue) chips covered with a single phosphor mixture used in high lumen density applications such as spots. However, a two-channel COB (with two individually addressable chip strings) may also be desirable, for example for tunable white spot applications. In the most cost-effective architecture, the chips in one of the strings are pre-applied with a warm white phosphor mixture, and then the entire light-emitting area is filled with a second (cool white) phosphor mixture that covers both the warm white chip string and the cool white chip string. In another example, the second phosphor mixture only covers the cool white string. By adjusting the current through the individual strings, various CCTs can be generated. There may be intermediate CCTs on the line connecting the two primary colors (color points of the warm white and cool white strings). If the two primary colors are located on the BBL, the intermediate color point may be located slightly below the BBL.

[0125] A third string can be introduced to widen the accessible color gamut, for example to adjust intermediate color points towards BBL. This can be done by using a green illuminant (direct green, or fully converted lime), or by using an intermediate "whitish" color point that does not lie on the line connecting the other two primaries (the three color points span a triangle in color space).

[0126] Another reason for adding a third channel to a COB is to be able to adjust the α-opic output of the device (for example) independent of the CCT. Such a device could be able to generate, for example, a 4000K white light with a high melanopic DER (daytime applications) or a low melanopic DER (nighttime applications). Preferably, these two settings have the same color point, on or near the BBL. To achieve this, the three color points of the individual channels (primaries) could be located on a single line in a color diagram. One of the three primaries required could be at a low CCT and two at a high CCT, since in the cool white part of the CCT range, an adjustment towards a high MDER could be required. In this specification, these primaries are sometimes denoted as WW (warm white), CW (cool white) (for low MDER) and CP (cyan primary) (for high MDER) (cool white), respectively. The WW and CW primaries may have normal blue chips, and the CP primaries may have cyan chips to increase the cyan intensity that may be needed to increase the MDER.

[0127] Three color points on a single line in color space can be achieved using various methods. The simplest method seems to be the adjustment of phosphors for each of the three channels. For example, the warm white channel uses a blue pump and phosphor pre-dispense step, similar to the approach currently used for two-channel COBs (see especially FIG. 1b). Furthermore, a second pre-dispense step (using a different phosphor mixture) is applied to the second channel (see FIG. 1b), followed by filling the LES with a third phosphor mixture. In this case, three different dispensing steps are required. This could be an embodiment, but may be less desirable due to process steps with intermediate curing and potential problems related to color targeting. Furthermore, since the phosphor deposited on the chips takes up more space than just the chip surface area, the chips may need to be spaced further apart, resulting in a larger light-emitting surface (LES), which is undesirable for COBs when used in spots.

[0128] In particular, it is proposed herein to cover two cold white strings with two different pump wavelengths with a single phosphor mixture. In the approach of FIG. 1a, this is used to fill the LES (light emitting surface) after pre-application in the WW channel, so that the three color points are aligned on a single line in color space. Surprisingly, it was found that by appropriate selection of chip wavelength and phosphors, it is possible to achieve this and to meet all other desired spectral requirements (CRI, R9, MDER). The second and third channels have different spectra (different pumps) that allow, for example, to adjust the melanopic DER (or α-opic parameters) independently of the CCT (an example is shown in FIG. 1).

[0129] Therefore, in an embodiment, we propose an adjustable melanopic lighting system that allows independent adjustment of melanopic DER and CCT, which requires a three-channel approach. A three-channel COB may consist of three individually addressable channels (WW, CW (low MDER), CW (high MDER)). One of the cool white channels uses a blue pump LED, whereas the high MDER channel (CP) uses a cyan pump LED. Both CW channels have the same phosphor. Many different options were simulated (see further below).

[0130] In the following, first, reference will be made to FIGS.

[0131] FIG. 1A is a schematic diagram of a light-generating system 1000 according to the present invention. FIG. 1B is a schematic diagram of a light-generating system 1000 according to the present invention. With reference to FIGS. 1A and 1B, the light-generating system 1000 may have a first SSL light source string 100 including one or more first SSL light sources 101 that generate blue light, a second SSL light source string 200 including one or more second SSL light sources 201 that generate blue light, and a third SSL light source string 300 including one or more third SSL light sources 301 that generate cyan light. With reference to FIG. 1A, the first luminescent material 400 may include one or more of a yellow, green, yellow / green, orange, red, or orange / red emitting luminescent material. The second luminescent material 400 may include one or more of an orange, red, or orange / red emitting luminescent material. 1B, the first luminescent material 400 may comprise a yellow / green emitting luminescent material, the second luminescent material 400 may comprise an orange, red or orange / red emitting luminescent material, and the third luminescent material 400 may comprise a yellow emitting luminescent material. In particular, the luminescent material 400 may comprise a red emitting luminescent material and a green emitting luminescent material. The luminescent materials may cover the first SSL light source 101, the second SSL light source 201 and the third SSL light source 301.

[0132] A light-generating system, such as a chip-on-board (COB) device, with three SSL light source strings allows the adjustment of the MDER value substantially independent of the correlated color temperature, in which the color points of the three SLL light source strings 100, 200, 300 are aligned on a substantially straight (single) line in color space, even if the luminescent materials on the second and third SSL light source strings are substantially the same. In other words, there are only two luminescent material application steps. The application of the first luminescent material may be on the first SSL light source string 100, or alternatively on the second and third SSL light source strings 200 and 300. If the application of the first luminescent material is on the first SSL light source string 100, the application of the second luminescent material may either cover all three SLL light source strings 100, 200, 300, or cover the second and third SSL light source strings 200 and 300. The color points of the light from the three different SLL light source channels are substantially on a single (straight) line in color space, which can be achieved using various methods. The simplest method seems to be the adjustment of the luminescent material for each of the three SLL light source channels. For example, the first SSL light source string 100 uses one or more blue LEDs and a pre-application step of luminescent material. Furthermore, a second pre-application step using a different luminescent material is applied to the second SSL light source light string 200 (see FIG. 1B), followed by the placement of a third luminescent material. In this case, three different application steps are required. In another example, the second and third SSL light source strings have substantially the same luminescent material (see FIG. 1A). The first SSL light source string has a different luminescent material (see FIG. 1A). The color points of the three SLL light source strings are on a single (straight) line in color space. By proper selection of the wavelengths of the SSL light sources and the luminescent materials of the three SLL light source strings, this can be achieved to obtain desired values ​​such as correlated color temperature and MDER value.

[0133] The second SLL light source string 200 and the third SLL light source string 300 may have different spectra that allow adjusting the MDER of the system light substantially independent of the correlated color temperature of the system light (see FIG. 2).

[0134] The (square) point on the line with the lowest x value, at approximately 0.23;0.3, may be denoted CP, where "CP" refers to the color point of the third SLL light source string 300, which is a cool white light. The larger (square) point on the line, at approximately 0.33;0.33, may be denoted CW (also cool white), where "CW" refers to the color point of the second SLL light source string 200. The larger (square) point on the right end of the line, at approximately 0.51;0.41, may be denoted WW, where "WW" refers to the color point of the first SLL light source string 100.

[0135] In FIG. 2, the first SSL light source string 100 and the second SSL light source string 200 have one or more blue LEDs with a peak wavelength of 430 nm, the third SSL light source string 300 has one or more cyan LEDs with a dominant wavelength of 477 nm, and the light generating system further comprises a BOSE F524 / BR2-607a mixture of luminescent materials, such as (divalent) europium doped silicate and divalent europium doped nitride.

[0136] The table below shows a first and second SSL light source string with blue LEDs (peak wavelength 430 nm), a third SSL light source string with cyan LEDs (dominant wavelength 473 nm), (A may specifically include Y (see also above)) and cerium doped A3(Ga,Al)5O 12 The (maximum) MDER values ​​are shown as a function of the correlated color temperature (CCT) and color rendering index (CRI) / R9 combination for a light generating system having a yellow phosphor such as garnet (GNYAG3557) and a red phosphor (BR2 / 607a). In an embodiment, the red phosphor may comprise divalent europium doped nitride.

[0137] In an embodiment, the first SSL light source string has a red phosphor and all SSL light source strings have a yellow phosphor. In other embodiments, the first SSL light source string may have (i) a yellow and / or green phosphor and (ii) a red phosphor (as the fourth luminescent material 500) and all SSL light source strings may have (a) a yellow and / or green phosphor and (b) a red phosphor (as the first (and / or second and / or third) luminescent material 400). In particular, the first luminescent material 400 may be configured downstream of the fourth luminescent material 500.

[0138] The excitation spectrum (thicker line; shorter wavelength portion of the graph) and emission spectrum (thinner line; longer wavelength portion of the graph) of a suitable luminescent material are illustrated in FIG. 4a.

[0139] The exemplary simulation starts with the selection of the blue pump wavelength (PWL) for the CW channel (low MDER). In the next step, the phosphor composition is determined to reach the desired color point. In the example shown here, the yellow phosphor is a "normal" garnet phosphor combined with a short-wavelength red emitter (BR2-607a). The target color point is 6500K (above the BBL), so the line connecting the warm white primary and the cool white primary intersects the BBL at 2200K and 5000K (requirement). In the last step, the cyan wavelength for the third channel is chosen so that the CP color point is on the same line (the line connecting the warm white primary and the cool white target point). Spectra are generated with different proportions of the three channels (2200K was chosen for the warm white channel).

[0140] After setting the CRI and R9 requirements as a function of CCT, the minimum and maximum values ​​of melanopic DER can be extracted (see table below). For certain applications, a low CTT setting is needed to have good light quality (CRI>90, R9>50), whereas at higher CCTs the requirements on light quality are less stringent (5000K, CRI>80). Using these light quality boundary conditions, the results can be summarized in a single graph (Figure 3). [Table 1] [Table 2]

[0141] Figure 3 summarizes the MDER range that can be reached per wavelength of green phosphor and blue chip, and which cyan chip wavelength is required for it. Four different luminescent materials are applied, indicated by references P1 to P4. The MDER range is shown as a function of CCT for four different phosphors, using blue LEDs of 435 nm indicated by bar a, 445 nm indicated by bar b, and 455 nm indicated by bar c. The light quality requirements can be, inter alia, 2200 to 4000K: CRI>90, R9>50, 4500K: CRI>85, R9>50, 5000K: CRI>80, R9>0.

[0142] FIG. 4a shows the excitation and emission spectra of suitable first, second and third luminescent materials (see also above).

[0143] FIG. 4b shows three light source spectra based on switching between at least one first SSL light source providing first light 105, at least one second SSL light source providing second light 205, and at least one third SSL light source providing third light 305.

[0144] The color point of the first light 105 is (2° CMF): CIE u' 0.2890, CIE v' 0.5365, the color point of the second light 205 is (2° CMF): CIE u' 0.1942, CIE v' 0.4787 and the color point of the third light 305 is (2° CMF): CIE u' 0.1746, CIE v' 0.4539 (see also table below). [Table 3]

[0145] Fig. 5 illustrates diagrammatically an embodiment of a luminaire 2 including a light-generating system 1000 as described above. Reference number 301 indicates a user interface that may be functionally coupled to a control system 302 included by or functionally coupled to the light-generating system 1000. Fig. 5 also illustrates diagrammatically an embodiment of a lamp 1 including the light-generating system 1000. Reference number 3 indicates a projector device or projector system that may be used to project an image onto a wall or the like, said projector device or projector system may also include the light-generating system 1000. Thus, Fig. 5 illustrates diagrammatically an embodiment of a lighting device 1200 selected from the group of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light-generating system 1000 as described herein. In an embodiment, such a lighting device may be a lamp 1, a luminaire 2, a projector device 3, a disinfection device, or an optical wireless communication device. Illumination device light escaping from the illumination device 1200 is indicated with reference numeral 1201. The illumination device light 1201 may essentially consist of the system light 1001, and therefore may be the system light 1001 in certain embodiments.

[0146] The term "plurality" refers to two or more.

[0147] The terms "substantially" or "essentially" and similar terms herein will be understood by those of skill in the art. The terms "substantially" or "essentially" may also include embodiments with "entirely," "completely," "all," and the like. Thus, in embodiments, the adjectives substantially or essentially may be omitted. Where applicable, the terms "substantially" or "essentially" may also relate to 90% or more, including 100%, such as 95% or more, particularly 99% or more, and even more particularly 99.5% or more.

[0148] The term "comprises" also includes embodiments in which the term "comprises" means "consisting of."

[0149] The term "and / or" specifically refers to one or more of the items mentioned before and after "and / or." For example, the phrase "item 1 and / or item 2," and similar phrases, can refer to one or more of item 1 and item 2. The term "comprising" can refer in some embodiments to "consisting of," while in other embodiments it can refer to "including at least the specified species, and optionally one or more other species."

[0150] Moreover, in the specification and claims, the terms first, second, third, etc. are used to distinguish between similar elements and are not necessarily used to describe a sequential or chronological order. The terms so used are interchangeable under appropriate circumstances, and it is to be understood that the embodiments of the invention described herein are capable of operation in orders other than those described or illustrated herein.

[0151] The present specification may describe, among other things, devices, apparatus, or systems in operation. As will be apparent to one of ordinary skill in the art, the present invention is not limited to methods of operation or devices, apparatus, or systems in operation.

[0152] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0153] The use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the specification and claims, words like "comprise" and the like should be interpreted in their inclusive sense, i.e., "including, but not limited to," as opposed to their exclusive or exhaustive sense.

[0154] The singular reference of an element does not exclude the presence of a plurality of such elements.

[0155] The invention may be implemented by means of hardware comprising several distinct elements, or by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain means are recited in mutually different dependent claims does not indicate that a combination of these means cannot be used to advantage. (Thus) in yet another aspect, the invention provides software which, when executed on a computer, is capable of implementing (one or more embodiments of) the method as described herein.

[0156] The present invention also provides a control system that may control a device, apparatus or system or that may perform the methods or processes described herein. Still further, the present invention also provides a computer program product that, when executed on a computer operatively coupled to or included in a device, apparatus or system, controls one or more controllable elements of such a device, apparatus or system.

[0157] The invention further applies to a device, an apparatus or a system having one or more of the characterizing features described in the specification and / or shown in the accompanying drawings.The invention further relates to a method or process having one or more of the characterizing features described in the specification and / or shown in the accompanying drawings.

Claims

1. a light-generating system configured to generate system light, the light-generating system comprising a first SSL light source string, a second SSL light source string, and a third SSL light source string; the first SSL light source string is configured to generate first light having a first color point and a first correlated color temperature CCT1, the first SSL light source string having at least one first SSL light source for generating purple and / or blue light and a first luminescent material; the second SSL light source string is configured to generate second light having a second color point and a second correlated color temperature CCT2, the second SSL light source string having at least one second SSL light source for generating purple and / or blue light and a second luminescent material; the third SSL light source string is configured to generate a third light having a third color point and a third correlated color temperature CCT3, the third SSL light source string having at least one third SSL light source for generating cyan light and a third luminescent material; the first correlated color temperature is lower than the second correlated color temperature; the first correlated color temperature is lower than the third correlated color temperature; the first SSL light source string is configured to generate warm white light, and the second SSL light source string and the third SSL light source string are configured to generate cool white light; the first color point, the second color point, and the third color point are on a straight line in a color diagram, and the first color point, the second color point, and the third color point do not overlap within 10 SDCM; the first SSL light source string, the second SSL light source string, and the third SSL light source string are individually controllable; A light producing system wherein the system light is substantially white light having a correlated color temperature in the range between 2200K and 6500K.

2. 2. The light-generation system of claim 1, wherein the first SSL light source is configured to generate first SSL light having a first dominant wavelength λ1d selected from a range of 440 to 470 nm, the second SSL light source is configured to generate second SSL light having a second dominant wavelength λ2d selected from a range of 425 to 470 nm, and the third SSL light source is configured to generate third SSL light having a third dominant wavelength λ3d selected from a range of 470 to 520 nm, and wherein (i) λ3d > λ2d and λ3d > λ1d, and / or (ii) λ3c > λ2c and λ3c > λ1c.

3. 3. The light generating system of claim 1, wherein the first light has a first MDER, the second light has a second MDER, and the third light has a third MDER, and the second MDER value is lower than the third MDER value.

4. 4. The light-generating system of claim 3, wherein the third MDER value is greater than both the first MDER value and the second MDER value, and at least two of the first MDER value, the second MDER value, and the third MDER value differ from each other by at least 0.

1.

5. 3. The light generating system of claim 1, further comprising a control system configured to individually control the first SSL light source string, the second SSL light source string and the third SSL light source string.

6. The first luminescent material and / or the second luminescent material and / or the third luminescent material are ３ B ５ O １２ 3. The light-generating system of claim 1, comprising a luminescent material of the Ce type, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and B comprises one or more of Al, Ga, In and Sc.

7. 3. The light generation system of claim 1, wherein the first luminescent material, the second luminescent material and the third luminescent material are substantially the same.

8. 3. The light generation system of claim 1, further comprising a fourth luminescent material different from the first luminescent material, the second luminescent material, and the third luminescent material, the fourth luminescent material being configured downstream of the at least one first SSL light source and not configured downstream of the at least one second SSL light source and the at least one third SSL light source.

9. 8. The light generation system of claim 7, wherein the first luminescent material, the second luminescent material, and the third luminescent material are configured downstream of all of the at least one first SSL light source, the at least one second SSL light source, and the at least one third SSL light source, and no other luminescent materials are configured downstream of the at least one second SSL light source and the at least one third SSL light source.

10. The light-generating system of claim 7 , wherein the second SSL light source string further comprises a fifth luminescent material.

11. 8. The light generating system of claim 7, wherein the fourth luminescent material is an orange and / or red luminescent material.

12. A light-generating system as described in any one of claims 1 to 2, wherein the third correlated color temperature CCT3 > 3000K, the second correlated color temperature CCT2 > 3000K, and the first correlated color temperature CCT1 ≦ 2700K.

13. 3. The light generating system of claim 1, wherein the first correlated color temperature differs from the second correlated color temperature and the third correlated color temperature by at least 1000 K, and all three color points determined based on 10° color matching functions are located within 10 SDCM of a substantially straight line on the color diagram.

14. 3. A light generating system as described in any one of claims 1 to 2, comprising a chip-on-board device, the chip-on-board device comprising the first SSL light source string, the second SSL light source string, the third SSL light source string, the first luminescent material, the second luminescent material and the third luminescent material.

15. 3. A lighting device selected from the group of a lamp, a luminaire and a projector device, comprising a light generation system according to any one of claims 1 to 2.

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