Light generating system

Abstract

The invention provides a light generation system (1000) comprising (a) a first light generation device (110) and (b) a control system (300), where: the first light generation device (110) is configured to generate first device light (111), where the first device light (111) comprises light having one or more wavelengths in a first wavelength range of 280-320 nm, and where the first device light (111) comprises light having one or more wavelengths in a second wavelength range of 280-320 nm; wherein the first wavelength range comprises a lower sub-range from [lambda] 11 to [lambda] 12 and a higher sub-range from [lambda] 21 to [lambda] 22, with 280 nm < = [lambda] 11 lt; lambda 12 < = lambda 21lt; lambda 22 < = 320 nm, and wherein Lambda 12 and Lambda 21 are selected from the wavelength range of 290-315 nm, and wherein the wavelength-dependent radiation flux of the first device light (111) is controllable; the light generating system (1000) is configured to generate system light (1001) comprising at least a portion of the first device light (111); the control system (300) is configured to control a wavelength dependent radiation flux of the first device light (111) as a function of time, wherein the light generation system (1000) is configured to provide the first device light (111) at a first time t1, at a second time t2 and at a third time t3; wherein the second time t2 is arranged temporally after the first time t1 and the third time t3 is arranged temporally after the second time t2; and wherein the first time t1, the second time t2 and the third time t3 are arranged in time in a day; wherein the radiation flux of the first device light (111) in the lower sub-range is relatively lower at a first time t1 than at a second time t2 with respect to the total radiation flux in the first wavelength range, and wherein the radiation flux of the first device light (111) in the lower sub-range is lower at a second time t2 with respect to the total radiation flux in the first wavelength range. The radiation flux of the first device light (111) in the higher sub-range is relatively higher at the first time t1 than at the second time t2; and / or wherein the radiation flux of the first device light (111) in the lower sub-range is relatively higher at the second time t2 than at the third time t3 with respect to the total radiation flux in the first wavelength range, and wherein the radiation flux of the first device light (111) in the lower sub-range is higher at the second time t2 than at the third time t3 with respect to the total radiation flux in the first wavelength range. The radiation flux of the first device light (111) in the higher sub-range is relatively lower at the second time t2 than at the third time t3.

Description

Technical Field

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

[0002] Light generating devices are known in the art. For example, US2020376292A1 describes a dynamic dose system for phototherapy and associated devices, systems, and methods. In some embodiments, the dynamic dose phototherapy system may include a self-service phototherapy kiosk ("SPK") configured to emit UV radiation, a user interface communicatively coupled to the SPK, and a dynamic dose system communicatively coupled to the user interface and the SPK. The dynamic dose system can determine initial user-specific parameters that are specific to defining a first body phototherapy regimen, and then determine adjustments to the initial parameters and the first body phototherapy regimen based on user input related to erythema response to a previous phototherapy treatment session. The SPK can deliver UV radiation to the user according to the first body phototherapy regimen and / or an adjusted second phototherapy regimen that takes into account the user's erythema response. Summary of the invention

[0003] Natural sunlight contains a wide variety of UV wavelengths, and the UV spectrum may vary significantly with changes in the solar zenith angle (SZA). For example, the UV spectrum may vary considerably depending on the solar zenith angle. At 45° north latitude, at low angles (sun high in the sky; e.g., at 6°), UV rays of ~290 nm may be much more abundant in the solar spectrum than at higher sun angles (sun at low altitude; e.g., at 86°). In particular, wavelengths above about 297 nm may be much more prevalent than wavelengths below about 297 nm in the morning, in the evening, and in winter.

[0004] The human body may contain various photoreceptors. Photoreceptors may regulate biological processes in the human body depending (at least in part) on the wavelength of light to which they are exposed. For example, the production of vitamin D in the human body may depend on the absorption of UVB by the skin. The vitamin D hormone (which may be important for health and, for example, for bone strength) may be the end result of a series of photochemical reactions that occur in the skin. In particular, the reaction constants of different photochemical reactions in the vitamin D synthesis pathway may be wavelength dependent.

[0005] Throughout human history, humans have been primarily exposed to natural sunlight (or "daylight"), and photoreceptors may have evolved accordingly to appropriately regulate biological processes based on exposure to sunlight, the spectrum of which may vary considerably throughout the day. Today, many people may be primarily exposed to artificial lighting, which may typically provide light with a single static spectrum throughout the day. Exposure to such a static spectrum may result in relatively static activation of photoreceptors, which may significantly affect biological processes, such as the synthesis of vitamin D. In particular, artificial light may provide relatively little vitamin D synthesis, as compared to sunlight.

[0006] Vitamin D deficiency may now be quite common, especially at high latitudes. Generally speaking, vitamin D deficiency can be addressed with food supplementation.

[0007] Therefore, one aspect of the present invention is to provide an alternative light generating system, which preferably further at least partially obviates one or more of the above disadvantages.An object of the present invention may be to overcome or ameliorate at least one disadvantage of the prior art, or to provide a useful alternative.

[0008] According to a first aspect, the present invention provides a light generating system ("system") comprising (a) a first light generating device and (b) a control system. In an embodiment, the first light generating device may be configured to generate a first device light, in particular wherein the first device light comprises light having one or more wavelengths in a first wavelength range of 280-320 nm. In particular, the first wavelength range may comprise from λ 11 to λ 12 The lower subrange of 21 to λ 22 The upper sub-range, especially where 280nm≤λ 11 <λ 12 ≤λ 21 <λ 22 ≤320nm, such as where λ 12 and λ 21A wavelength range selected from 290 - 315 nm. In a further embodiment, the wavelength - dependent radiant flux of the first device light is controllable. The light - generating system can in particular be configured to generate system light including (at least a part of) the first device light. The control system can be configured to control the wavelength - dependent radiant flux of the first device light as a function of time, especially where the light - generating system can be configured to provide the first device light at a first time t1, at a second time t2, and at a third time t3. The second time t2 is arranged in time after the first time t1, and the third time t3 is arranged in time after the second time t2. The first time t1, the second time t2, and the third time t3 are arranged in time during a day. Thus: t1 < t2 < t3. In particular, in an embodiment, the radiant flux of the first device light in the lower sub - range is relatively lower at the first time t1 than at the second time t2 with respect to the total radiant flux in the first wavelength range, and where the radiant flux of the first device light in the higher sub - range is relatively higher at the first time t1 than at the second time t2 with respect to the total radiant flux in the first wavelength range. In a further embodiment, the radiant flux of the first device light in the lower sub - range is relatively higher at the second time t2 than at the third time t3 with respect to the total radiant flux in the first wavelength range, and where the radiant flux of the first device light in the higher sub - range is relatively lower at the second time t2 than at the third time t3 with respect to the total radiant flux in the first wavelength range.

[0009] Thus, in a specific embodiment, the present invention can provide a light - generating system, which includes (a) a first light - generating device and (b) a control system, wherein: the first light - generating device is configured to generate first device light, where the first device light includes light having one or more wavelengths in a first wavelength range of 280 - 320 nm, where the first wavelength range includes a lower sub - range from λ 11 to λ 12 and a higher sub - range from λ 21 to λ 22 , where 280 nm ≤ λ 11 < λ 12 ≤ λ 21 < λ 22 ≤ 320 nm, and where λ 12 and λ 21A wavelength range selected from 290-315nm, wherein the wavelength-dependent radiant flux of the first device light is controllable; the light generating system is configured to generate system light including at least a portion of the first device light; the control system is configured to control the wavelength-dependent radiant flux of the first device light as a function of time, wherein the light generating system is configured to provide the first device light at a first time t1, at a second time t2, and at a third time t3; wherein the radiant flux of the first device light in a lower sub-range is relatively lower at the first time t1 than at the second time t2 relative to the total radiant flux in the first wavelength range, and wherein the radiant flux of the first device light in a higher sub-range is relatively higher at the first time t1 than at the second time t2 relative to the total radiant flux in the first wavelength range; and / or wherein the radiant flux of the first device light in a lower sub-range is relatively higher at the second time t2 than at the third time t3 relative to the total radiant flux in the first wavelength range, and wherein the radiant flux of the first device light in a higher sub-range is relatively lower at the second time t2 than at the third time t3 relative to the total radiant flux in the first wavelength range.

[0010] In aspects, in other words, the light generating system is configured to provide the first device light at two or more of the first time t1, the second time t2, and the third time t3. In aspects, the control system is configured to dynamically control the wavelength-dependent radiant flux of the first device light in the lower sub-range and in the upper sub-range as a function of time.

[0011] With such a light generating system, the (relative) abundance of light of different wavelengths can be varied during the day in order to dynamically stimulate the photoreceptors, such as by simulating natural sunlight. In particular, the light generating system can provide, at a second time t2, first device light having a higher proportion of radiant flux in a lower sub-range (relative to the total radiant flux in the first wavelength range) than at a first time t1 and / or at a third time t3. Thus, the second time t2 can, for example, correspond to midday, when the sun is at a low zenith angle, while the first time t1 and the third time t3 can, for example, correspond to morning and evening, when the sun is at a high zenith angle.

[0012] The present invention may be discussed herein primarily with respect to the synthesis of vitamin D, which synthesis may be generally known to be dependent on exposure to UV radiation. However, it will be clear to those skilled in the art that various other processes in the human body, such as those controlling circadian rhythms, may involve or be regulated by photoreceptors, and that the light generating systems of the present invention may also be beneficially applied in the context of regulating such processes.

[0013] As mentioned above, the synthesis of vitamin D may involve a series of biochemical reactions, which may be affected by different wavelengths of light in different ways. In particular, the light conversion of vitamin D related derivatives may strongly depend on wavelength. Because the spectral content of solar radiation changes during the day due to changes in the angle of the sun, especially in the UVB wavelength range (itself), the balance between different derivatives will also change during the day. For example, for the conversion of luminosterol (Lumi) to previtamin D3 (Pre), provitamin D3 (7-dehydrocholesterol, Pro) to Pre, and tachysterol (Tachy) to Pre, the quantum yield can be basically independent of the wavelength, but for Pre to Pro and Pre to Lumi, the quantum yield can rise at a longer wavelength (from about 300+nm), and for Pre to Tachy, the quantum yield can decrease at a longer wavelength (from about 300+nm). Therefore, the changing spectrum can significantly change the light generation of luminosterol and tachysterol from the derivatives of previtamin D. This situation may not occur substantially in the case of having a static spectrum and only intensity changes. Norval et al., "Is the action spectrum for the UV-induced production ofprevitamin D3 in human skin correct?", Photochemical & Photobiological Sciences, 2010, which is hereby incorporated by reference herein, calculated based on extinction coefficients determined in ethanol that when changing the wavelength of UV irradiation, there are distinct differences in the concentrations of previtamin D, provitamin D, and mixtures of lumisterol and tachysterol obtained. In particular, at wavelengths <290 nm, the main metabolic direction may be tachysterol. At wavelengths of about 280 to about 305 nm, the conversion may be directed to previtamin D at the expense of tachysterol, while at longer UVB wavelengths, a shift to lumisterol at the expense of previtamin D and tachysterol may occur. This may mean that when changing the solar spectrum during the day, during low solar zenith angles (midday) it may be evolutionarily preferred to be in the direction of synthesis of previtamin D and tachysterol, while at higher solar zenith angles (morning, late afternoon, and winter), synthesis may shift to reduced previtamin D and increased lumisterol. Although lumicesterol and tachysterol may have been considered in the past as inactive components of vitamin D synthesis, these vitamin D derivatives appear to be biologically active and may even be distinct from vitamin D.

[0014] Experimental studies using lasers and filtered arc lamps can show similar results. In particular, tachysterol levels may be highest at short UV wavelengths (such as at about 248 nm), and may be lowest at higher wavelengths (such as at about 308 nm). Previtamin D levels may be highest at intermediate wavelengths (such as at about 290 nm), and may stabilize during long-term exposure, while at shorter and longer wavelengths, previtamin D levels may decay with longer exposure times. Based on kinetic calculations and measurements from Terenetskaya, "Limitations of the photostationary approximation in thephotochemistry of provitamin D: The ambiguous role of their reversible degradation channel", Theoretical and Experimental Chemistry, 2008 (which is hereby incorporated by reference herein), the accumulation of previtamin D may be highest between 266 and 300 nm. Due to the establishment of kinetic equilibrium, the high accumulation of previtamin D may hinder further conversion. For further conversion, previtamin D may first need to be converted into vitamin D, tachysterol or tachysterol.

[0015] The light generating system of the present invention can provide, among other things, dynamic spectral shifts, such as for replicating the effects of sunlight on vitamin D anabolism. By having a dynamic UVB spectrum solution, it can provide a rich diversity of vitamin D in vitamin D synthesis, just like natural sunlight, as opposed to artificial static solutions and supplements. In particular, the light generating system of the present invention can facilitate (i) providing a variety of different vitamin D compounds throughout the day, similar to natural sunlight, (ii) depleting previtamin D in the skin to enhance the conversion from provitamin D to previtamin D upon subsequent exposure (due to altered reaction equilibrium kinetics), as natural sunlight in the morning and late afternoon would do; and providing the correct vitamin D metabolites at the correct time of day (circadian dynamic metabolite shift). For example, the present invention is a clear improvement over lighting systems that provide a single static spectrum including UVB.

[0016] Therefore, the present invention may provide a light generating system. The light generating system may include a first light generating device. The term "first light generating device" may also refer to a plurality of first light generating devices. In particular, the first light generating device may be configured to generate a first device light, and the light generating system may be configured to provide a system light, wherein the system light includes (at least a portion of) the first device light.

[0017] The first light generating device may be configured to generate a first device light; in particular wherein the first device light comprises light having one or more wavelengths in a first wavelength range. In an embodiment, the first wavelength range may comprise a range of 270-330 nm, such as a range of 280-320 nm. The first wavelength range may in particular comprise a UVB wavelength range.

[0018] In an embodiment, the first wavelength range may include from λ 11 to λ 12 The lower subrange of 21 to λ 22 The upper sub-range, especially where 280nm≤λ 11 <λ 12 ≤λ 21 <λ 22 ≤320nm. In another embodiment, λ 11 Can be selected from the range of 280-300nm, such as selected from the range of 280-295nm, especially selected from the range of 280-290nm. In another embodiment, λ 12 and λ 21 λ may be selected from a wavelength range of 285-315 nm, such as from a range of 290-315 nm, in particular from a range of 290-310 nm. In another embodiment, λ 22 λ may be selected from the range of 300-320 nm, such as from the range of 305-320 nm, and in particular from the range of 310-320 nm. In particular, in an embodiment, λ 11 can be selected from the range of 280-290nm, λ 12 and λ 21 can be selected from the range of 295-305nm, and λ 22 It can be selected from the range of 310-315 nm.

[0019] The first wavelength range may in particular consist of a first sub-range and a second sub-range. For example, in a specific embodiment, the first wavelength range may include a range of 280-300 nm, and the second wavelength range may include a range of 300-320 nm. However, in other embodiments, the first wavelength range may also include wavelengths outside the first sub-range and the second sub-range.

[0020] In an embodiment, the wavelength-dependent radiant flux of the first device light may be controllable, i.e. the first light generating device may be controlled to provide the first device light with different spectra. In particular, the spectrum of the first device light may be controlled by controlling the first light generating device. For example, in an embodiment, the radiant fluxes of different wavelengths may be (at least partially) controlled independently of each other.

[0021] The light generating system may further comprise a control system, in particular wherein the control system is configured to control the wavelength-dependent radiant flux of the first device light.Therefore, the control system may be configured to control the spectrum of the first device light.

[0022] In an embodiment, the control system can be configured to control, in particular in an operational mode, a wavelength-dependent radiant flux of the first device light as a function of time, in particular wherein the light generating system is configured to provide the first device light at one or more of a first time t1, a second time t2 and a third time t3 - in particular at least at the first time t1 and the second time t2, or in particular at least at the second time t2 and the third time t3.

[0023] As mentioned above, the second time t2 may correspond in particular to noon (at noon the sun is at a low zenith angle), while the first time t1 and the second time t3 may correspond to morning and / or evening (at which time the sun is at a high zenith angle). For example, in an embodiment, the first time t1 may be selected from the first daytime time range or the third daytime time range, in particular from the first daytime time range. Similarly, the second time t2 may be selected from the second daytime time range. However, similarly, the third time t3 may be selected from the third daytime time range or the first daytime time range, in particular from the third daytime time range.

[0024] In further embodiments, the first daytime time range may include a time range from 04:00 to 11:00, such as a time range from 04:00 to 10:00, and in particular a time range from 04:00 to 09:00.

[0025] In further embodiments, the second daytime time range may include a time range of 9:00 to 16:00, such as a time range of 10:00 to 15:00, and in particular a time range of 11:00 to 14:00.

[0026] In further embodiments, the third daytime time range may include a time range of 14:00 to 20:00, such as a time range of 15:00 to 20:00, and in particular a time range of 16:00 to 20:00.

[0027] Particularly, in the embodiment, when the first daytime time range, the second daytime time range, and the third daytime time range are selected, they do not overlap with each other in time.

[0028] It will be clear to a person skilled in the art that the spectrum of natural sunlight received at the surface of the Earth does not depend directly on the time of day, but may depend on the solar zenith angle (and on weather conditions), and that the spectrum of sunlight provided at a specific location at a specific time may depend, for example, on the geographical location of the specific location within a time zone, and on whether it is summer time or winter time at the specific location (if applicable). In particular, the spectrum of natural sunlight at a specific location may depend more directly on the time relative to solar noon, i.e. relative to the moment when the sun reaches its highest point in the sky for the specific location.

[0029] Thus, in an embodiment, the second daytime time range may include a range of TN-3–TN+3 times, wherein TN is solar noon, in particular wherein TN is solar noon at the location where the light generating system is located. For example, if solar noon is at 14:00 and the second daytime time range includes a range of TN-3–TN+3 times, the second daytime time range may include a range of 11:00–17:00 times. In further embodiments, the second time t2 may be selected from a range of TN-2.5–TN+2.5 times, such as from a range of TN-2–TN+2 times, in particular from a range of TN-1.5–TN+1.5 times.

[0030] Similarly, in an embodiment, the first daytime time range may include a range from 4:00 to TN-1.5 time, such as 4:00 to TN-2 time, and particularly 4:00 to TN-2.5 time, such as 4:00 to TN-3 time.

[0031] In further embodiments, the third daytime time range may include a range of TN+1.5–20:00 times, such as a range of TN+2–20:00 times, and in particular a range of TN+2.5–20:00 times, such as a range of TN+3–20:00 times.

[0032] Therefore, as described above, the first time t1, the second time t2 and the third time t3 can all be arranged in time in one day. In particular, especially in one day, the second time t2 can be arranged in time after the first time t1, and the third time t3 can be arranged in time after the second time t2.

[0033] In particular, all times mentioned herein are in 24-hour format. Thus, "11:00" corresponds to 11:00 am in the 12-hour format, and 11:00 pm in the 12-hour format will be referred to herein as "23:00".

[0034] In an embodiment, the control system can be configured, in particular in an operable mode, to control the wavelength-dependent radiant flux of the first device light so that one or more (in particular both) of the following apply: (a) relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light in a lower sub-range is relatively lower at the first time t1 than at the second time t2, and (b) relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light in a higher sub-range is relatively higher at the first time t1 than at the second time t2.

[0035] In further embodiments, the control system can be configured, in particular in an operable mode, to control the wavelength-dependent radiant flux of the first device light so that one or more (in particular both) of the following apply: (a) relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light in a lower sub-range is relatively higher at the second time t2 than at the third time t3, and (b) relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light in a higher sub-range is relatively lower at the second time t2 than at the third time t3.

[0036] In another embodiment, the control system can be configured, in particular in an operable mode, to control the wavelength-dependent radiant flux of the first device light so that (a) relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light in the lower sub-range is relatively lower at the first time t1 than at the second time t2, (b) relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light in the higher sub-range is relatively higher at the first time t1 than at the second time t2, (c) relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light in the lower sub-range is relatively higher at the second time t2 than at the third time t3, and (d) relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light in the higher sub-range is relatively lower at the second time t2 than at the third time t3.

[0037] In an embodiment, the control system may be configured, in particular in an operational mode, to control the first device light such that there is a gradual change, in particular a continuous change (see below), from Lt1 / Ft1 to Lt2 / Ft2 or in particular from Rt1 to Rt2 between t1 and t2 and / or between t2 and t3. In particular, in an embodiment, the gradual change in the lower sub-range may be at a rate of at least (approximately) 0.1*(Lt2-Lt1) per hour. Similarly, in an embodiment, the gradual change in the upper sub-range may be at a rate of at least (approximately) 0.1*(Ht2-Ht1) per hour.

[0038] Thus, some time may pass between t1 and t2, wherein the radiant flux of the first device light gradually changes. For example, in an embodiment, t1 and t2 may be at least 0.5 hours apart, such as at least 1 hour apart, in particular at least 2 hours apart.

[0039] Alternatively, in an embodiment, the control system can be configured, in particular in an operational mode, to control the first device light so that there is a step change between t1 and t2, in particular an instantaneous change from Lt1 / Ft1 to Lt2 / Ft2 or in particular from Rt1 to Rt2 (see below). For example, in such an embodiment, t1 can be arranged in time within 5 minutes, such as within 1 minute, in particular within 10 seconds, from t2. Similarly, in such an embodiment, t3 can be arranged in time within 5 minutes, such as within 1 minute, in particular within 10 seconds, from t2.

[0040] The term "control" and similar terms refer in particular at least to determining the operation of a behavior or a supervisory element. Therefore, in this article, "control" and similar terms may, for example, refer to applying behavior (determining the operation of a behavior or a supervisory element) to an element, such as, for example, measuring, displaying, actuating, opening, transferring, changing temperature, etc. In addition, the term "control" and similar terms may additionally include monitoring. Therefore, the term "control" and similar terms may include applying behavior to an element, and also applying behavior to an element and monitoring the element. The control of the element may be completed with a control system, which may also be indicated as a "controller". Therefore, the control system and the element may be functionally coupled at least temporarily or permanently. The element may include a control system. In an embodiment, the control system and the element may not be physically coupled. Control may be completed via wired and / or wireless control. The term "control system" may also refer to a plurality of different control systems, which are particularly functionally coupled, and in these control systems, for example, one control system may be a master control system, and one or more other control systems may be slave control systems. The control system may include or may be functionally coupled to a user interface.

[0041] The system or device or equipment may perform actions in a "mode" or "operating mode" or "operable mode". The term "operable mode" may also be indicated as a "control mode". Similarly, in a method, an action or phase or step may be performed in a "mode" or "operating mode" or "operable mode". This does not exclude that the system or device or equipment may also be adapted to provide another control mode, or multiple other control modes. Similarly, this may not exclude that one or more other modes may be executed before and / or after executing the mode.

[0042] As described above, the first light generating device may be configured to provide a first device light having different levels of wavelength-dependent radiant flux that vary over time. In an embodiment, the first light generating device may be configured to provide a first device light having in a first wavelength range (i) a first total radiant flux Ft1 at a first time t1 (or "time t1") and (ii) a second total radiant flux Ft2 at a second time t2 (or "time t2"), i.e., Ft1 and Ft2 may be the radiant fluxes in the first wavelength range at time t1 and time t2, respectively. Similarly, in an embodiment, the first light generating device may be configured to provide a first device light in a lower sub-range (i) a first lower radiant flux Lt1 at a first time t1 and (ii) a second lower radiant flux Lt2 at a second time t2 (or "time t2"), i.e., Lt1 and Lt2 may be the radiant fluxes at the lower sub-ranges at time t1 and time t2, respectively. In another embodiment, the first light generating device can be configured to provide a first device light in a higher sub-range (i) a first higher radiant flux Ht1 at a first time t1 and (ii) a second higher radiant flux Ht2 at a second time t2 (or "time t2"), that is, Ht1 and Ht2 are the radiant fluxes of the higher sub-range at time t1 and time t2, respectively.

[0043] In such embodiments, one or more of the following may apply: (a) Lt2 / Ft2≥1.01*Lt1 / Ft1, and (b) Ht2 / Ft2≤0.99*Ht1 / Ft1.

[0044] In another embodiment, Lt2 / Ft2≥1.01*Lt1 / Ft1, such as Lt2 / Ft2≥1.05*Lt1 / Ft1, especially Lt2 / Ft2≥1.10*Lt1 / Ft1. In another embodiment, Lt2 / Ft2≥1.2*Lt1 / Ft1, such as Lt2 / Ft2≥1.5*Lt1 / Ft1, especially Lt2 / Ft2≥2*Lt1 / Ft1. In another embodiment, Lt2 / Ft2≥5*Lt1 / Ft1, such as Lt2 / Ft2≥10*Lt1 / Ft1, especially Lt2 / Ft2≥20*Lt1 / Ft1.

[0045] In other embodiments, Ht2 / Ft2≤0.99*Ht1 / Ft1, such as Ht2 / Ft2≤0.98*Ht1 / Ft1, especially Ht2 / Ft2≤0.97*Ht1 / Ft1, such as Ht2 / Ft2≤0.95*Ht1 / Ft1, especially such as Ht2 / Ft2≤0.9*Ht1 / Ft1.

[0046] In particular, towards solar noon, such as from t1 to t2, the radiant flux of natural sunlight may increase throughout the first wavelength range. However, this increase may be relatively greater at shorter wavelengths than at longer wavelengths (see also Figure 1B ). Therefore, compared with the full radiant flux in the first wavelength range, the relative radiant flux in the higher wavelength range can be reduced from t1 to t2 (Ht1 / Ft1>Ht2 / Ft2), while in the lower sub-range, the relative radiant flux from t1 to t2 can be increased considerably (Lt1 / Ft1>Ht2 / Ft2). <Lt2 / Ft2)。

[0047] For example, in an embodiment, one or more of the following may apply, in particular both of them may apply: (a) Lt2 / Ft2≥2*Lt1 / Ft1, and (b) Ht2 / Ft2≤0.95*Ht1 / Ft1.

[0048] Similarly, in an embodiment, Ft3, Ht3, and Lt3 are the radiant flux in the first wavelength range, in the upper wavelength range, and in the lower sub-range, respectively, at time t3. In a further embodiment, Lt2 / Ft2>2*Lt3 / Ft3. In yet another embodiment, Ht2 / Ft2<0.99*Ht3 / Ft3.

[0049] In another embodiment, Lt2 / Ft2≥1.01*Lt3 / Ft3, such as Lt2 / Ft2≥1.05*Lt3 / Ft3, especially Lt2 / Ft2≥1.10*Lt3 / Ft3. In another embodiment, Lt2 / Ft2≥1.2*Lt3 / Ft3, such as Lt2 / Ft2≥1.5*Lt3 / Ft3, especially Lt2 / Ft2≥2*Lt3 / Ft3. In another embodiment, Lt2 / Ft2≥5*Lt3 / Ft3, such as Lt2 / Ft2≥10*Lt3 / Ft3, especially Lt2 / Ft2≥20*Lt3 / Ft3.

[0050] In other embodiments, Ht2 / Ft2≤0.99*Ht3 / Ft3, such as Ht2 / Ft2≤0.98*Ht3 / Ft3, especially Ht2 / Ft2≤0.97*Ht3 / Ft3, such as Ht2 / Ft2≤0.95*Ht3 / Ft3, especially such as Ht2 / Ft2≤0.9*Ht3 / Ft3.

[0051] Similarly, in an embodiment, at a first time t1, the light generating system may provide a first device light having a first radiant flux ratio Rt1 of radiant flux in the upper sub-range relative to radiant flux in the lower sub-range; and at a second time t2, the light generating system provides a first device light having a second radiant flux ratio Rt2 of radiant flux in the upper sub-range relative to radiant flux in the lower sub-range; wherein Rt1 / Rt2≥2. In particular, in an embodiment, the following may apply: Rt1=Ht1 / Lt1, Rt2=Ht2 / Lt2, and Rt1 / Rt2>1, such as ≥1.5, in particular ≥2, such as ≥5. In further embodiments, the following may apply: Rt3=Ht3 / Lt3, Rt2=Ht2 / Lt2, and Rt3 / Rt2>1, such as ≥1.5, in particular ≥2, such as ≥5.

[0052] In another embodiment, 2≤Rt1 / Rt2≤2000, in particular 3≤Rt1 / Rt2≤1000, such as 5≤Rt1 / Rt2≤500. Similarly, in another embodiment, 2≤Rt3 / Rt2≤2000, in particular 3≤Rt3 / Rt2≤1000, such as 5≤Rt3 / Rt2≤500.

[0053] As described above, the present invention may facilitate providing (to a person) system light that mimics sunlight, which may beneficially stimulate biological processes. In particular, in an embodiment, the light generating system (and in particular the control system) may be configured to provide the first device light according to an (average) daily pattern, such as in view of latitude and time of year. For example, in an embodiment, the control system may be configured to control the first device light depending on one or more of the (current) season (of the year) and the latitude of the light generating system (i.e., the latitude corresponding to the geographical location of the light generating system).

[0054] In a further embodiment, the light generating system may comprise a sensor or be functionally coupled to a sensor, wherein the control system is configured to control the first light generating device, in particular the first device light, depending on the sensor. In particular, the sensor may be configured to sense a parameter and provide a relevant parameter signal to the control signal, wherein the control system is configured to control the first device light depending on the relevant parameter signal. For example, in an embodiment, the sensor may comprise one or more presence sensors, such as a motion sensor and a daylight sensor.

[0055] In an embodiment, the sensor may include a presence sensor such as a motion sensor, the presence sensor being configured to detect whether the space is occupied and provide a presence-related signal to the control system, wherein the control system is configured to control the first light generating device based on the presence-related signal. For example, in an embodiment, the light generating system may be configured to provide system light to the space, and the presence sensor is configured to detect whether the space is occupied, and the control system may be configured to control the first light generating device to only provide the first device light if the space is occupied based on the presence-related signal.

[0056] In particular, in an embodiment, the sensor may comprise a daylight sensor, in particular wherein the daylight sensor is configured to sense (natural) daylight and provide a relevant daylight signal to the control system.

[0057] The term "daylight related signal" may refer herein to a signal related to detected daylight. In particular, the daylight related signal may include raw data and / or processed data related to (detected) daylight, such as raw data and / or processed data related to a radiant flux in the daylight, in particular in the first wavelength range.

[0058] In further embodiments, the control system may be configured to control the first light generating device based on a daylight related signal to provide a first device light that simulates (detected) (substantially) concurrent daylight, in particular wherein the control system is configured to control the first light generating device based on a daylight related signal to provide a first device light that simulates a radiant flux in concurrent daylight.

[0059] Although the present invention may be described herein primarily in the context of spectral variations that mimic natural daylight in an everyday pattern, it will be clear to those skilled in the art that the present invention is not limited to such embodiments. For example, given that different wavelengths of light can manipulate biological processes in different directions (via photoreceptors), it may be advantageous to provide relative differences that are greater than those that naturally occur as a function of solar zenith angle, such as by (substantially) temporally separating the presence of different wavelengths in the first device light. Thus, the light generating system of the present invention can (substantially) facilitate independent control of different biological processes by providing relevant wavelengths (for these processes) at different times.

[0060] For example, in an embodiment, one or more of the following, in particular all, may be applied: Lt1 / Ft1≤0.1; Lt2 / Ft2≥0.9; and Lt3 / Ft3≤0.1, such as at least Lt1 / Ft1≤0.1 and Lt2 / Ft2≥0.9. In such an embodiment, at a first time (and at a third time), the abundance of the radiant flux in the lower sub-range is relatively low relative to the total radiant flux in the first wavelength range, while at a second time t2, the radiant flux in the lower sub-range may represent the vast majority of the total radiant flux in the first wavelength range.

[0061] In other embodiments, Lt1 / Ft1≤0.2, such as Lt1 / Ft1≤0.1, especially Lt1 / Ft1≤0.01, such as Lt1 / Ft1≤0.001, including 0. In other embodiments, Lt2 / Ft2≥0.5, especially Lt2 / Ft2≥0.75, such as Lt2 / Ft2≥0.9, such as Lt2 / Ft2≥0.95, including 1. In other embodiments, Lt3 / Ft3≤0.2, such as Lt3 / Ft3≤0.1, especially Lt3 / Ft3≤0.01, such as Lt3 / Ft3≤0.001, including 0.

[0062] As described above, in natural daylight, in the first wavelength range, the relative change in the radiant flux between (early) morning and solar noon may be greater for shorter wavelengths than for longer wavelengths. Therefore, the change in the shorter wavelengths may occur relatively quickly. Similarly, in an embodiment, during the change period tc, the relative change in the wavelength-dependent radiant flux of the first device light depending on time may be greater in the lower sub-range than in the higher sub-range.

[0063] In particular, in an embodiment, the control system may be configured to provide a gradual change during a variation period tc (see above). In a further embodiment, t1 and t2 may be arranged in the variation period tc. In a further embodiment, the variation period tc may have a duration selected from the range of 0.5-10 hours, in particular from the range of 1-8 hours, such as from the range of 2-4 hours.

[0064] In further embodiments, CL may be |Lt1-Lt2| / (0.5*(Lt1+Lt2)), and CH may be |Ht1-Ht2| / (0.5*(Ht1+Ht2)), in particular where CL>CH, such as CL≥1.5*CH, in particular CL≥2*CH, such as CL≥3*CH.

[0065] Similar to the variation period tc during which the relative radiant flux (in the first wavelength range) in the first device light may vary, the light generating system may be further configured to provide a holding period th during which the relative radiant flux may remain substantially constant. In further embodiments, during the holding period th, the lower sub-range λ 11 -λ 12 The radiant flux Lh of the first device light and the upper sub-range λ 21 -λ 22 The radiant flux Hh of the first device light in Lh remains substantially constant, such as wherein Lh and Hh each vary by at most 5%, such as at most 3%, in particular at most 1% during the holding period th. In particular, the holding period th may be selected from a second daytime time range. In further embodiments, the holding period th may have a duration of at least 1 hour, such as at least 2 hours, in particular at least 3 hours. In further embodiments, the light generating system may be configured to provide the first device light with a (substantially) constant spectral composition during the holding period th.

[0066] In an embodiment, the first light generating device may be configured to generate first device light having a first spectral power, at least 85%, in particular at least 90%, such as at least 95% (including 100%) of which is in the first wavelength range.

[0067] In a further embodiment, the first wavelength range may comprise n first wavelength range portions, in particular n first wavelength range portions of (approximately) equal length. In such an embodiment, the first device light integrated over the variation period tc may comprise a radiant flux in k of these first wavelength range portions, in particular wherein n is selected from the range of 2-8, such as from the range of 3-7, in particular from the range of 4-6, and in particular wherein 2≤k≤n, such as 3≤k≤n, in particular 4≤k≤n.

[0068] As will be clear to those skilled in the art, overexposure to UV radiation may be undesirable, for example in view of potential adverse health effects.Accordingly, the irradiance of the light generating device may be selected based on health and / or safety (such as in accordance with national and international guidelines).

[0069] In an embodiment, the first light generating device may be configured to generate a first device light having a power selected from ≤3 mW / m in the first wavelength range at a distance of 1 m from the first light generating device. 2 , especially ≤1mW / m 2 A range of irradiance, especially actinic-weighted irradiance.

[0070] The term "actinic-weighted irradiance" as used herein corresponds to the term as defined in standard IEC 62471 Chapter 4, which is hereby incorporated herein by reference and which is known to a person skilled in the art.

[0071] Since the light generating system of the present invention is intended to provide system light to a person, the light generating system may also beneficially provide visible light. For example, assuming that the lack of visible light is noticeable, while the lack of UVB may be imperceptible, a person may be more likely to keep the light on if the light also provides visible light. Furthermore, a light source providing visible light may tend to be appropriately arranged to illuminate a space, which may also provide a suitable arrangement for the first light generating device.

[0072] Therefore, in an embodiment, the light generating system may further include a second light generating device, in particular wherein the second light generating device is configured to generate a second device light having one or more wavelengths in the visible light wavelength range. In particular, in an operational mode of the system, the system light may include one or more of (i) (at least a portion of) the first device light and (ii) (at least a portion of) the second device light, in particular (at least a portion of) the first device light and (at least a portion of) the second device light.

[0073] In particular, in an embodiment, the second light generating device may be configured to generate a white second device light, in particular wherein the correlated color temperature of the second device light is controllable, and in particular wherein the control system is configured to control the correlated color temperature of the second device light as a function of time. In particular, for a user of the light generating system, such as an occupant of a room that the light generating system is configured to illuminate, it may be beneficial to have a visual cue that the light generating system is active and / or working. Generally, one may associate UV with a purple or blue hue. Thus, the light generating system may, for example, be configured to provide warmer light (i.e., with a higher CCT) at the second time t2 compared to the first time t1 and / or the third time t3.

[0074] In further embodiments, the second light generating device may be configured to provide infrared (IR) radiation, such as near IR radiation, particularly in the range of 750-3000 nm. In particular, NIR may be involved in the recovery / aging of cells and may therefore be beneficial in the case of providing UV. NIR may be applied before, simultaneously with or after UV exposure. Therefore, in an embodiment, the system light may include the first device light and the second device light at the same time, or the first device light and the second device light may be provided with a time interval.

[0075] The light generating system may be part of or may be applied in, for example, an office lighting system, a home application system, a store lighting system, a family lighting system, an accent lighting system, a spotlight lighting system, a theater lighting system, a fiber optic application system, a projection system, a self-luminous display system, a pixelated display system, a segmented display system, a warning sign system, a medical lighting application system, an indicator sign system, a decorative lighting system, a portable system, an automotive application, a (outdoor) road lighting system, a city lighting system, a greenhouse lighting system, horticultural lighting, digital projection, or an LCD backlight. The light generating system (or illuminator) may be part of or may be applied in, for example, an optical communication system or a disinfection system.

[0076] The light generating system (particularly the first light generating device, or particularly the second light generating device) may comprise a light source.In embodiments, the (first / second) device light may comprise one or more of light source light and converted light source light (such as luminescent material light).

[0077] The term "white light" and similar terms are known to the person skilled in the art in this document. It may particularly relate to light having a correlated color temperature (CCT) between about 1800K and 20000K, such as between 2000 and 20000K, in particular 2700-20000K, for general lighting, in particular in the range of about 2000-7000K, such as in the range of 2700K and 6500K. In an embodiment, for example for the purpose of backlighting, or for other purposes, the correlated color temperature (CCT) may in particular be in the range of about 7000K and 20000K. Still further, in an embodiment, the correlated color temperature (CCT) is in particular within about 15SDCM (standard deviation of color matching) from the BBL (black body locus), in particular within about 10SDCM from the BBL, even more in particular within about 5SDCM from the BBL.

[0078] In a specific embodiment, the correlated color temperature (CCT) may be selected from the range of 6000-12000 K, such as from the range of 7000-12000 K, such as at least 8000 K. Still further, in an embodiment, the correlated color temperature (CCT) may be selected from the range of 6000-12000 K, such as from the range of 7000-12000 K, in combination with a CRI of at least 70.

[0079] The term "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 context, UV may particularly refer to a wavelength selected from the range of 190-380 nm, such as 200-380 nm.

[0080] The terms "light" and "radiation" are used interchangeably herein, unless it is clear from the context that the term "light" refers only to visible light. The terms "light" and "radiation" may therefore refer to UV radiation, visible light, and IR radiation. In specific embodiments, particularly for lighting applications, the terms "light" and "radiation" refer (at least) to visible light.

[0081] The term IR radiation may refer in specific embodiments to near IR radiation (NIR).Thus, the term "(N)IR" is also used herein to refer generally to IR and in specific embodiments to NIR.

[0082] The term "violet light" or "violet emission" particularly relates to light having a wavelength in the range of about 380-440 nm. The term "blue light" or "blue emission" particularly relates to light having a wavelength in the range of about 440-495 nm (including some violet and cyan hues). The phrase "light having one or more wavelengths in a wavelength range" and similar phrases may particularly indicate that the indicated light (or radiation) has a spectral power distribution with one or more intensities at least at these one or more wavelengths in the indicated wavelength range. For example, a solid-state light source emitting blue will have a spectral power distribution with intensities at one or more wavelengths in the wavelength range of 440-495 nm.

[0083] The control system may also be configured to receive and execute instructions from a remote control. In an embodiment, the control system may be controlled via an App on a device such as a portable device (e.g., a smartphone or I-Phone, a tablet, etc.). Thus, the device is not necessarily coupled to the lighting system, but may be (temporarily) functionally coupled to the lighting system.

[0084] 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 a control in slave mode. For example, the lighting system may be identifiable with a code, in particular a unique code for the respective lighting system. The control system of the lighting system may be configured to be controlled by an external control system, which accesses the lighting system based on knowledge of the (unique) code (entered via a user interface or using an optical sensor (e.g. a QR code reader)). The lighting system may also include means for communicating with other systems or devices, such as based on Bluetooth, Thread, WIFI, LiFi, ZigBee, BLE or WiMAX, or other wireless technologies.

[0085] However, in an embodiment, a control system may be available which is adapted to at least provide a control mode. If other modes are available, the selection of such a mode may in particular be performed via a user interface, although other options (such as performing a mode depending on a sensor signal or a (time) scheme) may also be possible. In an embodiment, an operating mode may also refer to a system, or a device, or an apparatus that can only be operated in a single operating mode (i.e. "on", without further tunability).

[0086] Thus, in an embodiment, the control system may be controlled depending on one or more of an input signal of a user interface, a sensor signal (of a sensor), and a timer.The term "timer" may refer to a clock and / or a predetermined time scheme.

[0087] In another aspect, the present invention may provide a lighting device selected from the group including lamps, illuminators, projector devices, disinfection devices, photochemical reactors, phototherapy lighting devices and optical wireless communication devices, which includes a light generating system according to any of the preceding claims; in particular, a lighting device selected from the group including lamps, illuminators and phototherapy lighting devices.

[0088] Therefore, the present invention can also provide a lamp or illuminator including a light generating system as defined herein. The illuminator may further include a housing, an optical element, a shutter, etc. The lamp or illuminator may further include a housing that encloses the light generating system. The lamp or illuminator may include a light window or housing opening in the housing, through which the system light escapes from the housing. In yet another aspect, the present invention also provides a projection device including a light generating system as defined herein. In particular, a projection device or "projector" or "image projector" may be an optical device that projects an image (or moving image) onto a surface (such as, for example, a projection screen). The projection device may include one or more light generating systems such as described herein. Therefore, in one aspect, the present invention also provides a light generating device selected from a group of lamps, illuminators, projector devices, disinfection equipment, photochemical reactors, and optical wireless communication devices, including a light generating system as defined herein. The light generating device may include a housing or carrier configured to accommodate or support one or more elements of the light generating system.

[0089] Instead of the term "lighting device" or "lighting system" and similar terms, the term "light generating device" or "light generating system" (and similar terms) may also be applied. A lighting device or a lighting system may be configured to generate device light (or "lighting device light") or system light (or "lighting system light"). As mentioned above, the terms light and radiation may be used interchangeably. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which corresponding reference numerals indicate corresponding parts, and in which:

[0091] Figure 1A Embodiments of light generating systems are schematically depicted.

[0092] Figure 1B Schematic depiction of the natural UVB spectrum composition at different times during the day.

[0093] Figure 1C-Figure 1D Aspects relating to embodiments of a light generating system are schematically depicted.

[0094] Figure 2 Embodiments of lighting devices are schematically depicted.

[0095] The schematic drawings are not necessarily to scale. DETAILED DESCRIPTION

[0096] FIG1 schematically depicts embodiments (I) and (II) of a light generating system 1000 including a first light generating device 110 and a control system 300. In the depicted embodiment, the first light generating device 110 is configured to generate a first device light 111. In the depicted embodiment, the light generating system 1000 is configured to generate a system light 1001 including at least a portion of the first device light 111. In particular, the first device light 111 may include light having one or more wavelengths in a first wavelength range of 280-320 nm. In particular, in an embodiment, the first wavelength range may include wavelengths from λ to λ. 11 to λ 12 The lower subrange of 21 to λ 22 The upper sub-range, especially where 280nm≤λ 11 <λ 12 ≤λ 21 <λ 22 ≤320nm, and especially where λ 12 and λ 21Selected from the wavelength range of 290-315nm. In further embodiments, the wavelength-dependent radiant flux of the first device light 111 is controllable, in particular wherein the control system 300 is configured to control the wavelength-dependent radiant flux of the first device light 111 as a function of time. In particular, in an embodiment, the light generating system 1000 may be configured to provide the first device light 111 at a first time t1 and a second time t2 (in particular at the first time t1, the second time t2 and the third time t3). In an embodiment, relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light 111 in the lower sub-range is relatively lower at the first time t1 than at the second time t2, and relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light 111 in the higher sub-range is relatively higher at the first time t1 than at the second time t2. In other embodiments, relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light 111 in the lower sub-range is relatively higher at the second time t2 than at the third time t3, and relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light 111 in the higher sub-range is relatively lower at the second time t2 than at the third time t3.

[0097] In an embodiment, the first light generating device 110 may be configured to generate a first device light 111 having an (actinically weighted) irradiance in a first wavelength range at a distance of 1 m from the first light generating device 110 (or from the light generating system 1000), the irradiance being selected from ≤ 3 mW / m 2 , especially ≤1mW / m 2 range.

[0098] In the depicted embodiment, the light generating system 1000 may further include a sensor 310 or be functionally coupled to a sensor 310. In particular, the sensor 310 may be configured to sense a parameter, such as a sunlight spectrum, and provide a parameter-related signal to the control system 300, in particular wherein the control system 300 is configured to control the first light generating device 110 based on the parameter-related signal.

[0099] For example, in an embodiment, the control system 300 may be configured to control the first device light 111 dependent on the sensor 310, wherein the sensor 310 comprises a daylight sensor. In further embodiments, the sensor 310 may comprise a presence sensor or a motion sensor.

[0100] In further embodiments, the control system 300 may be configured to control the first device light 111 depending on one or more of the (current) season (of the year) and the latitude of the light generating system 1000 .

[0101] In the depicted embodiment (II), the light generating system 1000 further includes a second light generating device 120, in particular wherein the second light generating device 120 is configured to generate a second device light 121 having one or more wavelengths in the visible light wavelength range. In further embodiments, in an operational mode of the system 1000, the system light 1001 may include one or more of (i) at least a portion of the first device light 111 and (ii) at least a portion of the second device light 121, in particular at least a portion of the first device light 111 and at least a portion of the second device light 121.

[0102] In particular, in an embodiment, the second light generating device 120 may be configured to generate white second device light 121, wherein the correlated color temperature of the second device light 121 is controllable, and in particular wherein the control system 300 is configured to control the correlated color temperature of the second device light 121 as a function of time.

[0103] Figure 1B Schematically depicts the energy in W / m at different times during the day (t = 12:00, 10:00 or 8:00). 2 The irradiance I in units of nm is compared to the UVB spectral component of sunlight at wavelength λ in nm. The ratio change at each wavelength between morning (t=8:00) and afternoon (t=12:00) indicates that the naturally varying spectrum is not just the result of an intensity shift. In the shorter wavelength UVB range, the ratio shift of the afternoon intensity relative to the morning intensity can be at least 2 orders of magnitude, such as about 723 times at 290nm, while the ratio shift of the total UVB change may be only 4 times. For example, at 300nm, the ratio shift may be about 43, and at 310nm, the ratio shift may be about 6.

[0104] In another embodiment, Ht1 and Ht2 may be the radiation flux of the higher sub-range at time t1 and time t2, respectively, where CL is |Lt1-Lt2| / 0.5*Lt1+Lt2; CH is |Ht1-Ht2| / 0.5*Ht1+Ht2; and CL≥2*CH.

[0105] Figure 1B The lower and upper sub-ranges and the λ 11 , 12 , 21 and λ 22 For example, in the depicted embodiment, λ 11 can be about 292nm, λ 12 can be about 299nm, λ 21 can be about 302 nm, and λ 22It can be about 307nm.

[0106] In another embodiment, λ 11 can be selected from the range of 280-290nm, λ 12 and λ 21 can be selected from the range of 295-305nm, and λ 22 It can be selected from the range of 310-315 nm.

[0107] As described above, the light generating system may be configured to provide system light at a first time t1 and a second time t2, such as where the system light at the first time t1 corresponds to sunlight at a high zenith angle, and where the system light at the second time t2 corresponds to system light at a low zenith angle. Figure 1B Schematically depicted, the first time t1 may be (approximately) 8:00 and the second time t2 may be (approximately) 12:00.

[0108] In an embodiment, the first time t1 can be selected from a first daytime time range, wherein the first daytime time range is from 04:00 to 10:00 hours, and the second time t2 can be selected from a second daytime time range, wherein the second daytime time range is from 10:00 to 15:00 hours. In another embodiment, t3 can be selected from a third daytime time range, wherein the third daytime time range is from 15:00 to 20:00 hours.

[0109] In another embodiment, at a first time t1, the light generating system 1000 can provide a first device light 111 having a first radiant flux ratio Rt1 of the radiant flux in the higher sub-range relative to the radiant flux in the lower sub-range; and at a second time t2, the light generating system 1000 can provide a first device light 111 having a second radiant flux ratio Rt2 of the radiant flux in the higher sub-range relative to the radiant flux in the lower sub-range; in particular, wherein Rt1 / Rt2≥2.

[0110] Figure 1C Aspects of system light 1001 of two embodiments of light generating systems (referred to as (I) and (II)) are schematically depicted. Specifically, Figure 1C The variation of the ratio L / F in the system light 1001 over time t is schematically depicted, where L is the radiant flux in the lower sub-range, and where F is the (total) radiant flux in the first wavelength range. For example, with respect to embodiment (I), the ratio L / F is schematically depicted as increasing from t1 to t2, and decreasing from t2 to t3.

[0111] exist Figure 1CIn the embodiment (II) of FIG. 1 , the ratio L / F remains substantially constant during a holding period th, wherein the holding period extends from the second time t2 to the second end time t2′. In particular, in the depicted embodiment, during the holding period th, the lower sub-range λ 11 -λ 12 The radiant flux Lh of the first device light 111 and the upper sub-range λ 21 -λ 22 The radiant flux Hh of the first device light 111 in the maintenance period th is kept substantially constant, wherein the maintenance period th is selected from the second daytime time range. In further embodiments, the maintenance period th may have a duration of at least 2h. In further embodiments, the light generating system 1000 may be configured to provide the first device light having a substantially constant spectral composition during the maintenance period th.

[0112] In further embodiments, Ft1 and Ft2 may be the radiation flux in the first wavelength range at time t1 and time t2, respectively; Lt1 and Lt2 may be the radiation flux of the lower sub-range at time t1 and time t2, respectively; and Ht1 and Ht2 may be the radiation flux of the upper sub-range at time t1 and time t2, respectively. In further embodiments, Lt2 / Ft2≥1.01*Lt1 / Ft1, such as Lt2 / Ft2≥1.1*Lt1 / Ft1, in particular Lt2 / Ft2≥2*Lt1 / Ft1. In further embodiments, Ht2 / Ft2≤0.99*Ht1 / Ft1, such as Ht2 / Ft2≤0.98*Ht1 / Ft1, in particular Ht2 / Ft2≤0.95*Ht1 / Ft1.

[0113] Similarly, in an embodiment, Ft3 and Lt3 may be the radiant flux in the first wavelength range and in the lower sub-range, respectively, at time t3. In a further embodiment, Lt2 / Ft2>2*Lt3 / Ft3. In a further embodiment, Ht2 / Ft2<0.99*Ht3 / Ft3.

[0114] exist Figure 1C In the embodiment depicted in , the control system 300 may specifically be configured to control the first device light 111 such that there is a gradual change from Lt1 / Ft1 to Lt2 / Ft2 (and / or specifically from Rt1 to Rt2) between t1 and t2.

[0115] Figure 1D Aspects of system light 1001 of two embodiments of light generating systems, referred to as (I) and (II), are schematically depicted. In particular, Figure 1DThe variation of the intensity in the lower sub-range L and in the upper sub-range H over time t is schematically depicted. In the depicted embodiment, the light generating system may be configured at a first time t1 (and at a third time t3) to provide light in the upper sub-range, but substantially no light in the lower sub-range, while at a second time t2 the light generating system may be configured to provide light in the lower sub-range, but substantially no light in the upper sub-range.

[0116] In particular, in the depicted embodiment: Lt1 / Ft1≤0.1; Lt2 / Ft2≥0.9; and Lt3 / Ft3≤0.1.

[0117] In the described embodiment, there is a bit of "dead time" where substantially no light in the lower sub-range is provided, and no light in the upper sub-range is provided.

[0118] In another embodiment, the control system 300 can be configured to control the first device light 111 so that there is a gradual change between t1 and t2, especially an instantaneous change from Lt1 / Ft1 to Lt2 / Ft2. For example, in such an embodiment, t1 can be arranged in time within 10s starting from t2.

[0119] exist Figure 1D In the embodiment (II), during the variation period tc, the time-dependent relative variation of the wavelength-dependent radiant flux of the first device light 111 may be greater in the lower sub-range than in the upper sub-range.

[0120] Figure 2 An embodiment of a luminaire 2 comprising a light generating system 1000 as described above is schematically depicted. Reference numeral 301 denotes a user interface which may be functionally coupled with a control system 300 comprised by or functionally coupled to the light generating system 1000. Figure 2 Also schematically depicted is an embodiment of a lamp 1 comprising a light generating system 1000. Reference numeral 3 indicates a projector device or a projector system, which may be used for projecting an image, such as on a wall, which may also comprise the light generating system 1000. Thus, Figure 2Schematically depicted is an embodiment of a lighting device 1200, which is 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 a 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. Lighting device light escaping from the lighting device 1200 is indicated with reference numeral 1201. The lighting device light 1201 may essentially consist of the system light 1001, and may therefore in a specific embodiment be the system light 1001. Reference numeral 1300 refers to a space, such as a room.

[0121] The term "plurality" means two or more.

[0122] Those skilled in the art will understand the terms "substantially" or "essentially" and similar terms herein. The terms "substantially" or "essentially" may also include embodiments with "completely", "completely", "all", etc. Therefore, in embodiments, the adjectives substantially or substantially may also be removed. Where applicable, the terms "substantially" or "essentially" may also relate to 90% or higher, such as 95% or higher, particularly 99% or higher, even more particularly 99.5% or higher, including 100%.

[0123] The term "comprising" also includes embodiments in which the term "comprising" means "consisting of.

[0124] 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 may refer to one or more of item 1 and item 2. The term "comprising" may mean "consisting of" in one embodiment, but may also mean "including at least the defined categories and optionally one or more other categories" in another embodiment.

[0125] In addition, the terms first, second, third, etc. in the specification and claims are used to distinguish between similar elements and not necessarily to describe a sequential or temporal order. It should be understood that the terms so used are interchangeable under appropriate circumstances, and that the embodiments of the invention described herein are capable of operation in other sequences than those described or illustrated herein.

[0126] During operation, an apparatus, device or system may be described herein - among other things. As will be clear to one skilled in the art, the present invention is not limited to methods of operation, or apparatus, devices or systems in operation.

[0127] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

[0128] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0129] 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, the words "comprises," "comprising," etc. should be interpreted in an inclusive sense, rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to."

[0130] The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0131] The invention can be implemented by means of hardware comprising several distinct elements, and 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 measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0132] The present invention also provides a control system that can control a device, apparatus or system, or can perform the method or process described herein. Still further, the present invention also provides a computer program product that, when functionally coupled to a device, apparatus or system or run on a computer included in the device, apparatus or system, controls one or more controllable elements of such a device, apparatus or system.

[0133] The present invention further applies to an apparatus, device or system comprising one or more characterizing features described in the specification and / or shown in the attached drawings. The present invention further relates to a method or process comprising one or more characterizing features described in the specification and / or shown in the attached drawings.

[0134] The various aspects discussed in this patent can be combined to provide additional advantages. In addition, those skilled in the art will appreciate that the embodiments can be combined, and more than two embodiments can also be combined. In addition, some features can form the basis of one or more divisional applications.

Claims

1. A light generating system (1000), comprising (a) a first light generating device (110) and (b) a control system (300), wherein: The first light generating device (110) is configured to generate a first device light (111), wherein the first device light (111) comprises light having one or more wavelengths in a first wavelength range of 280-320 nm, wherein the first wavelength range comprises light from λ 11 to λ 12 The lower subrange of 21 to λ 22 The upper sub-range, where 280nm≤λ 11 <λ 12 ≤λ 21 <λ 22 ≤320nm, and where λ 12 and λ 21 selected from a wavelength range of 290-315 nm, wherein the wavelength-dependent radiant flux of the first device light (111) is controllable; - the light generating system (1000) is configured to generate system light (1001) comprising at least a portion of the first device light (111); - the control system (300) is configured to control a wavelength-dependent radiant flux of the first device light (111) as a function of time, wherein the light generating system (1000) is configured to provide the first device light (111) at a first time t1, at a second time t2 and at a third time t3; wherein the second time t2 is arranged in time after the first time t1, and the third time t3 is arranged in time after the second time t2; as well as wherein the first time t1, the second time t2 and the third time t3 are arranged in time in one day; - wherein the radiant flux of the first device light (111) in the lower sub-range is relatively lower at the first time t1 than at the second time t2 relative to the total radiant flux in the first wavelength range, and wherein the radiant flux of the first device light (111) in the higher sub-range is relatively higher at the first time t1 than at the second time t2 relative to the total radiant flux in the first wavelength range; and / or - wherein relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light (111) in the lower sub-range is relatively higher at the second time t2 than at the third time t3, and wherein relative to the total radiant flux in the first wavelength range, the radiant flux of the first device light (111) in the higher sub-range is relatively lower at the second time t2 than at the third time t3.

2. The light generating system (1000) according to claim 1, wherein: - Ft1 and Ft2 are the radiation fluxes in said first wavelength range at time t1 and time t2 respectively; - Lt1 and Lt2 are the radiation flux of said lower sub-range at time t1 and time t2 respectively; - Ht1 and Ht2 are the radiation flux of said higher sub-range at time t1 and time t2, respectively; as well as - One or more of the following apply: (a) Lt2 / Ft2 ≥ 1.01*Lt1 / Ft1, and (b) Ht2 / Ft2 ≤ 0.99*Ht1 / Ft1.

3. The light generating system (1000) of claim 2, wherein one or more of the following apply: (a) Lt2 / Ft2≥2*Lt1 / Ft1, and (b) Ht2 / Ft2≤0.95*Ht1 / Ft1.

4. The light generating system (1000) according to any of the preceding claims 2-3, wherein: - Ft3 and Lt3 are the radiant flux in said first wavelength range and in said lower sub-range, respectively, at time t3; -Lt2 / Ft2>2*Lt3 / Ft3.

5. The light generating system (1000) according to claim 4, wherein: -Lt1 / Ft1≤0.1; -Lt2 / Ft2≥0.

9.

6. A light generating system (1000) according to any of the preceding claims, wherein t1 is selected from a first daytime time range, wherein the first daytime time range is from 04:00 to 10:00 hours, and wherein t2 is selected from a second daytime time range, wherein the second daytime time range is from 10:00 to 15:00 hours, and wherein t3 is selected from a third daytime time range, wherein the third daytime time range is from 15:00 to 20:00 hours.

7. The light generating system (1000) according to any one of the preceding claims, wherein during the varying period t c During this time, a relative change in the wavelength-dependent radiant flux of the first device light (111) as a function of time is greater in the lower sub-range than in the upper sub-range.

8. The light generating system (1000) according to any of the preceding claims 2-7, wherein: -CL is |Lt1-Lt2| / (0.5*(Lt1+Lt2)) -CH is |Ht1-Ht2| / (0.5*(Ht1+Ht2)) -CL≥2*CH.

9. The light generating system (1000) according to any one of the preceding claims, wherein: - at the first time t1, the light generating system (1000) provides a first device light (111) having a first radiant flux ratio Rt1 of the radiant flux in the upper sub-range relative to the radiant flux in the lower sub-range; - at the second time t2, the light generating system (1000) provides a first device light (111) having a second radiant flux ratio Rt2 of the radiant flux in the upper sub-range relative to the radiant flux in the lower sub-range; -where Rt1 / Rt2≥2.

10. The light generating system (1000) according to any one of the preceding claims, wherein: - Ft1 and Ft2 are the radiation fluxes in said first wavelength range at time t1 and time t2 respectively; - Lt1 and Lt2 are the radiation flux of said lower sub-range at time t1 and time t2 respectively; wherein the control system (300) is configured to control the first device light (111) such that there is a gradual change from Lt1 / Ft1 to Lt2 / Ft2 between t1 and t2.

11. The light generating system (1000) according to any one of the preceding claims, wherein: - Ft1 and Ft2 are the radiation fluxes in said first wavelength range at time t1 and time t2 respectively; - Lt1 and Lt2 are the radiation flux of said lower sub-range at time t1 and time t2 respectively; wherein the control system (300) is configured to control the first device light (111) such that there is a stepwise change from Lt1 / Ft1 to Lt2 / Ft2 between t1 and t2.

12. The light generating system (1000) according to any one of the preceding claims 3 to 10, wherein during a holding period t h During the period, in the lower sub-range λ 11 -λ 12 The radiant flux Lh of the first device light (111) in the upper sub-range λ 21 -λ 22 The radiation flux Hh of the first device light (111) in the device is kept substantially constant, wherein the holding period t h Selected from the second daytime time range; The second daytime time range includes the time range from 9:00 to 16:

00.

13. The light generating system (1000) according to any of the preceding claims, wherein the control system (300) is configured to control the first device light (111) dependent on a sensor (310), wherein the sensor (310) comprises a daylight sensor.

14. The light generating system (1000) according to any of the preceding claims, further comprising a second light generating device (120), wherein the second light generating device (120) is configured to generate a second device light (121) having one or more wavelengths in the visible light wavelength range, and wherein in an operable mode of the system (1000), the system light (1001) comprises one or more of: (i) at least a portion of the first device light (111); and (ii) at least a portion of the second device light (121).

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

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