Melanopic Photosensitivity

Abstract

The present invention provides a light-generating system (1000) comprising one or more light-generating devices (100), each of which is configured to generate a device light (101), the light-generating system (1000) configured to generate a system light (1001) comprising the device light (101) of at least one light-generating device (100), the light-generating system (1000) being configured to provide (in an operational mode) the system light (1001) according to the following characteristics: (A) during a first time period t1, the system light (1001) has a radiant flux Φ11 in a first wavelength range and a radiant flux Φ12 in a second wavelength range. (B) during a second time period t2, the system light (1001) is light having a radiant flux Φ21 in a first wavelength range and a radiant flux Φ22 in a second wavelength range; (C) during a third time period t3, the system light (1001) is light having a radiant flux Φ31 in a first wavelength range and a radiant flux Φ32 in a second wavelength range; (D) Φ21<Φ11, Φ31<Φ11; (E) Φ22>Φ12, Φ32<Φ12; (F) t2 is selected from the range of 1 second to 30 minutes, t1>t2; and (G) the first wavelength range is 380 nm to λ1, the second wavelength range is λ1 to 780 nm, and λ1 is selected from the range of 485 to 550 nm.

Description

[Technical field]

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

[0002] Lighting devices designed for circadian effects are known in the art. For example, US11071187 describes a circadian entrainment enhancement device including a housing, a first directional light source, a second directional light source, and a driver. During daytime, the driver turns on the first directional light source with a high melanopic ratio to enhance the daytime circadian entrainment of the user. During nighttime, the driver turns on the second directional light source with a low melanopic ratio to enhance the nighttime circadian entrainment of the user. US11071187 also describes using a light sensor, a memory module, and a calculation module to calculate the required light output of the device by considering the ambient light level. US11071187 also describes using a distance sensor to adjust the light level of the light source according to the distance between the device and the user.

[0003] US2013 / 0119891A1 discloses a method for controlled lighting of an area by a lighting system, the method comprising the steps of providing, by the lighting system, general lighting during a predetermined general lighting period and colored lighting during a first predetermined colored lighting period according to a predetermined time program. The predetermined time program is executed for at least 6 hours. Further, in the method a control unit is applied, configured to control the lighting system according to the predetermined time program.

[0004] US2019 / 0387593A1 discloses an exemplary device configured to emit a first light having a first luminous flux and a peak intensity at a first wavelength that is between 400 nanometers (nm) and 480 nm. The first luminous flux is variable and / or the emission of the first light is interrupted one or more times. The device is also configured to emit a second light having a second luminous flux and a peak intensity at a second wavelength that is between 500 nm and 630 nm. The second luminous flux is variable and / or the emission of the second light is interrupted one or more times. The first luminous flux is at a maximum at least when the second luminous flux is not at a maximum. Summary of the Invention [Problem to be solved by the invention]

[0005] It appears that bright light in the evening, especially short-wavelength light, can suppress the natural build-up of melatonin, the pineal hormone involved in preparing our body to fall asleep. The mechanism underlying the suppression of melatonin may begin with the absorption of light in the melanopsin photopigment, present in a small proportion of retinal ganglion cells (ipRGCs). These cells can signal to the brain (SCN) and cause signal changes that initiate the synthesis of melatonin in the pineal gland. Thus, melatonin production appears to be adversely affected by the stimulation of melanopsin by light. The strength of melanopsin stimulation is quantified by the melanopic EDI (abbreviated herein as MEDI), see also, for example, 2018 CIE S 026 - CIE system for metrology of optical radiation for ipRGC-influenced responses to light, which is incorporated herein by reference. The degree to which light can stimulate melanopsin, and thus its potential to affect (the suppression of) melatonin production, can be quantified by the melanopic equivalent daylight illuminance, also known as melanopic EDI or MEDI. The lower the MEDI at night, the better the readiness for sleep is likely to be. Therefore, lighting applications that support a going-to-bed routine may target a low MEDI at night, preferably a MEDI of 10 lx for 2-3 hours before bedtime. One strategy is to lower the illuminance level. Another strategy is to shift to lower CCT values ​​(e.g., 2700K, or even 2200K) and / or modify the light spectrum to minimize the radiance in the cyan part of the spectrum, where melanopsin is most sensitive. However, it is desirable to provide improved lighting devices that can affect circadian rhythms differently or better.

[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 mentioned disadvantages. The present invention may have the objective of overcoming or ameliorating at least one of the disadvantages of the prior art, or of providing a useful alternative. [Means for solving the problem]

[0007] According to a first aspect, the present invention provides a light-generating system ("system") including one or more light-generating devices, each of which is configured to generate a device light. In an embodiment, the light-generating system may be configured to generate a system light including the device light of at least one light-generating device (of the one or more light-generating devices). In particular, in an embodiment, the light-generating system may be configured to provide (in an operational mode) a system light according to the following characteristics: (a) during a first time period t1, the system light is visible light, more particularly white light, and (b) during a second time period t2, the system light has a different spectral power distribution than the system light during the first time period. Optionally, during a third time period t3, the system light may be provided to have a spectral power distribution that may be the same as during the first time period or the second time period, or may be different from both. In a particular embodiment, during a first time period t1, the system light may be (white) light having a radiant flux Φ11 in a first wavelength range and a radiant flux Φ12 in a second wavelength range, during a second time period t2, the system light may be light having a radiant flux Φ21 in a first wavelength range and a radiant flux Φ22 in a second wavelength range, and optionally during a third time period t3, the system light may be light having a radiant flux Φ31 in a first wavelength range and a radiant flux Φ32 in a second wavelength range. In particular, in some embodiments, the following condition may apply: Φ21<Φ11, Φ22>Φ12, t2 is selected from the range of 1 second to 30 minutes, and the first wavelength range may be 380 nm to λ1, the second wavelength range may be λ1 to 780 nm, and λ1 may be selected from the range of 485 to 550 nm. Furthermore, in some embodiments, the following conditions may (also) apply: Φ31<Φ11, Φ32<Φ12, and t1>t2.Therefore, in particular, the present invention provides a light-generating system comprising one or more light-generating devices, each of which is configured to generate a device light, the light-generating system being configured to generate a system light comprising the device light of the at least one light-generating device, the light-generating system being configured to provide (in an operational mode) the system light according to the following characteristics: (A) during a first time period t1, the system light is visible light, in particular white light, having a radiant flux Φ11 in a first wavelength range and a radiant flux Φ12 in a second wavelength range; (B) during a second time period t2, the system light is light having a radiant flux Φ21 in a first wavelength range and a radiant flux Φ22 in a second wavelength range; (C) during a third time period t3, the system light is light having a radiant flux Φ31 in a first wavelength range and a radiant flux Φ32 in a second wavelength range; (D) Φ21<Φ11, Φ31<Φ11; (E) Φ22>Φ12, Φ32<Φ12; (F) t2 is selected from the range of 1 second to 30 minutes, t1>t2; and (G) the first wavelength range is 380 nm to λ1, the second wavelength range is λ1 to 780 nm, and λ1 is selected from the range of 485 to 550 nm.

[0008] With such a system, a kind of booster light pulse may be provided, which can unexpectedly have a beneficial effect on circadian rhythms. Instead of reducing the intensity, a relatively strong light pulse may be provided just before going to sleep, which can have a beneficial effect. Without being bound by theory, the present invention can use the (counter-intuitive) application of a short period of relatively high intensity light to force a portion of the melanopsin pigment (a portion that can actively contribute to brain signaling) into a silent state. This can effectively reduce the disturbance of melatonin build-up due to light, which is beneficial in preparing to fall asleep. Thus, the present invention can provide a go-to-sleep routine that includes, among other things, a booster light pulse.

[0009] As indicated above, the light-generating system may include one or more light-generating devices. In particular, each of the one or more light-generating devices may be configured to generate device light. The light-generating devices may be configured to generate device light. In particular, the light-generating devices may include a light source. The light source may be configured to generate source light. In some embodiments, the device light may consist essentially of the device light. In other embodiments, the device light may consist essentially of converted light source light. In still other embodiments, the device light may include (unconverted) source light and converted source light. The source light may be converted to luminescent material light using a luminescent material and / or to upconverted light using an upconverter (see also below). The term "light-generating device" may also refer to multiple light-generating devices that may provide device light with essentially the same spectral power distribution. In certain embodiments, the term "light-generating device" may also refer to multiple light-generating devices that may provide device light with different spectral power distributions.

[0010] The term "light source" may in principle relate to any light source known in the art. This may be a conventional (tungsten) light bulb, a low-pressure mercury lamp, a high-pressure mercury lamp, a fluorescent lamp, a light emissive diode (LED). In certain embodiments, 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 also refer in certain embodiments to so-called chips-on-board (COB) light sources. The term "COB" refers in particular to LED chips in the form of semiconductor chips that are not encapsulated or connected, but are directly mounted on a substrate, such as a PCB. Thus, several light-emitting semiconductor light sources may be configured on the same substrate. In certain embodiments, the COB is a multi-LED chip configured together as a single lighting module.

[0011] The light source may have a light escape surface. With reference to conventional light sources such as light bulbs or fluorescent lamps, the light escape surface may be the outer surface of the glass or quartz envelope. In the case of an LED, the light escape surface may for example be the LED die or the outer surface of the resin if the resin is applied to the LED die. 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 thus escapes from the light exit surface of the light source.

[0012] Similarly, the light-generating device may include a light escape surface, such as an end window.Furthermore, similarly, the light-generating system may include a light escape surface, such as an end window.

[0013] 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 includes a solid-state light source (such as an LED or a laser diode). In one embodiment, the light source includes an LED (light emitting diode). The term "light source" or "solid state light source" may also refer to a superluminescent diode (SLED).

[0014] Additionally, the term "LED" may refer to multiple LEDs.

[0015] The term "light source" may also refer to multiple (essentially identical (or different)) light sources, such as 2-2000 solid-state light sources. In some embodiments, the light source may include one or more micro-optical elements (array of microlenses) downstream of a single solid-state light source, such as an LED, or downstream of multiple solid-state light sources (i.e., shared by multiple LEDs, for example). In some embodiments, the light source may include an LED with on-chip optics. In some embodiments, the light source includes a single LED that is pixelated (with or without optics) (which in some embodiments provides on-chip beam steering).

[0016] In some embodiments, the light sources may be configured to provide primary radiation used by themselves, 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 referred to as direct color LEDs.

[0017] However, in other embodiments, the light source may be configured to provide a primary radiation, and a portion of the primary radiation may be converted to a secondary radiation. The secondary radiation may be based on conversion by the luminescent material. Hence, the secondary radiation may also be referred to as luminescent material radiation. The luminescent material may be included in the light source, such as, in some embodiments, an LED having 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 a distance ("remote") from the light source, such as an LED having 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 emits light of a wavelength selected from the range of at least 380-470 mm during operation. However, other wavelengths may be possible. This light may be used, in part, by the luminescent material.

[0018] In some embodiments, the light-generating device may include a luminescent material. In some embodiments, the light-generating device may include a PC LED. In other embodiments, the light-generating device may include a direct LED (i.e., no phosphor). In some embodiments, the light-generating device may include a laser device, such as a laser diode. In some embodiments, the light-generating device may include a superluminescent diode. Thus, in certain embodiments, the light source may be selected from the group of a laser diode and a superluminescent diode. In other embodiments, the light source may include an LED.

[0019] 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 have one or more bands, which in some embodiments have a bandwidth as known for lasers.

[0020] The term "light source" may thus refer to the light generating element itself, e.g. a solid-state light source, or may refer to a package of a light generating element, e.g. a solid-state light source, and one or more of an element containing a luminescent material and (other) optics, e.g. a lens, a collimator, etc. A light converter element ("converter element" or "converter") may include an element containing a luminescent material. A solid-state light source itself, e.g. a blue LED, is a light source. Also, a combination of a solid-state light source (as a light generating element) and a light converter element, e.g. a blue LED and a light converter element optically coupled to the solid-state light source, may also be a light source (but may be indicated as a light generating device). Thus, a white LED is a light source (but may be indicated as a (white) light generating device, for example).

[0021] As used herein, the term "light source" may also refer to light sources, including solid-state light sources, such as LEDs, laser diodes, superluminescent diodes, and the like.

[0022] The term "light source" may (thus) in some embodiments refer to a light source based (also) on conversion of light, such as a light source in combination with a luminescence converter material. Thus, the term "light source" may also refer to a combination of an LED and a luminescent material configured to convert at least a portion of the LED emission, or a combination of a (diode) laser and a luminescent material configured to convert at least a portion of the (diode) laser emission.

[0023] In some 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) elements, such as optical filters and / or beam shaping elements.

[0024] The phrases "distinct light sources" or "multiple distinct light sources" and similar phrases may, in some 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 some embodiments, refer to multiple solid-state light sources selected from the same bin.

[0025] A "solid state light source" or "solid state material light source" and similar terms may refer to semiconductor light sources, such as light emitting diodes (LEDs), diode lasers, or superluminescent diodes, among others.

[0026] In particular, the light-generating system is configured to generate a system light. The system light may include the device light of at least one light-generating device (of one or more light-generating devices). More particularly, the system light may consist essentially of the device light of at least one light-generating device. In particular, the system light has a controllable spectral power distribution and a controllable radiant flux. The term "radiant flux" may in particular refer to the radiant energy emitted per unit time (by the light-generating device). Instead of the term "radiant flux", the terms "intensity" or "radiant power" may be applied. The term "radiant flux" may in particular have units of energy, such as watts. The term "spectral power distribution" may in particular refer to the power distribution of light (in particular in watts) as a function of wavelength (in particular in nanometers), particularly over the human visible wavelength range (380-780 nm) in some embodiments. In particular, the term "spectral power distribution" may refer to the radiant flux per unit frequency or wavelength, often expressed in watts / nm. Instead of the term "spectral power distribution", the term "spectral flux" may be applied. Thus, instead of the phrase "controllable spectral power distribution", the phrase "controllable spectral flux" may be applied. Spectral flux may be expressed as power (Watts) per unit frequency or wavelength. In particular, in this specification, spectral flux is expressed as radiant flux per unit wavelength (W / nm). Furthermore, in this specification, spectral flux and radiant flux are based on the spectral power of the device light, in particular over the wavelength range of 380 to 780 nm.The term "correlated color temperature" may, inter alia, refer herein to the temperature of a Planckian radiator having a chromaticity closest to the chromaticity associated with a given spectral distribution on the modified 1976 UCS diagram, where u', 2 / 3v' are the coordinates of the Planckian locus and the test stimulus.

[0027] The system light may be controllable, and therefore in particular the spectral power distribution and the radiant flux. To this end, in particular the system may comprise a light-generating device having a controllable spectral power distribution and / or may comprise two or more light-generating devices. In the former embodiment(s), the light-generating device having a controllable spectral power distribution may be controlled by the control system. In the latter embodiment(s), the spectral power distribution of the system light may be controlled by controlling two or more light-generating devices by the control system.

[0028] Therefore, in particular, the light-generating system may include or be functionally coupled to a control system. The control system may in particular be configured to control one or more light-generating devices. In embodiments with more than one light-generating device, the control system may be configured to control the light-generating devices individually (or to control a set of light-generating devices individually (see also below)). In particular, the control system may be configured to control the system light (more in particular the radiant flux and the spectral power distribution of the system light).

[0029] The term "control" and similar terms may refer, among other things, to at least determining the behavior of an element or supervising the execution of an element. Thus, in this specification, "control" and similar terms may refer to imposing a behavior on an element (determining the behavior of an element or supervising the execution of an element), such as, for example, measuring, indicating, activating, opening, shifting, changing temperature, etc. Additionally, the term "control" and similar terms may additionally include monitoring. Thus, the term "control" and similar terms may include imposing a behavior on an element, and may also include imposing a behavior on an element and monitoring an element. Control of an element can be performed using 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. An element may include a control system, although in some embodiments, the control system and the element may not be physically coupled. Control can be performed via wired and / or wireless control. The term "control system" may also refer to a number of different control systems that are particularly functionally coupled, where for example one control system may be a master control system and one or more other control systems may be slave control systems. A control system may include a user interface or be functionally coupled to a user interface.

[0030] The control system may also be configured to receive and execute instructions from a remote control. In some embodiments, the control system may be controlled via an app on a portable device, e.g. a smart phone or an I-phone, a tablet, etc. Thus, the device may be (temporarily) functionally coupled to the light-generating system, without necessarily being coupled to the light-generating system.

[0031] 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 light-generating system may be a slave control system or may control in slave mode. For example, the light-generating systems may be identifiable by a code, in particular a code unique to the respective light-generating system. The control system of the light-generating system may be configured to be controlled by an external control system that can access the light-generating system based on knowledge of the (unique) code (entered by means of an optical sensor, e.g. a QR code reader or by a user interface). The light-generating system may also include means for communicating with other systems or devices, for example based on Bluetooth, WiFi, LiFi, ZigBee, BLE or WiMAX, or other wireless technologies.

[0032] A system, or an apparatus, or a device may perform an action in a "mode" or "operation mode" or "mode of operation" or "operational mode". The term "operational mode" may also be indicated as a "controlling mode". Similarly, in a method, an action, or a phase, or a step may be performed in a "mode" or "operation mode" or "mode of operation" or "operational mode". This does not exclude that the system, or an apparatus, or a device may be adapted to provide another control mode, or multiple other control modes. Similarly, this does not exclude that one or more other modes may be performed before performing a mode and / or after performing a mode.

[0033] However, in some embodiments, a control system may be available that is adapted to provide at least the control mode. If other modes are available, the selection of such modes may be performed particularly via a user interface, although other options are possible, such as implementing the mode depending on a sensor signal or a (time) scheme. An operational mode may refer in some embodiments to a system, or apparatus, or device that can only operate in a single operational mode (i.e., "on", without further tunability).

[0034] Thus, in an embodiment, the control system may be controlled in dependence on one or more of a user interface input signal, a sensor signal (of a sensor), and a timer. The term "timer" may refer to a clock and / or a predefined time scheme.

[0035] The light-generating system may be operable in a single operational mode in some embodiments, as may be derived from the above, or in other embodiments, different operational modes may be selected (e.g., via a user interface, based on a sensor signal, and / or based on a timer (signal)). In particular, an operational mode is described herein in which the light-generating system provides (white) light during a first time period, and then provides a boost of light, which may generally mean that the radiant flux of light in a wavelength range below a certain wavelength is lower and the radiant flux of light in a wavelength range above a certain wavelength is higher, during a second time period. Then (during a third time period), the system may provide light in some embodiments with a lower radiant flux than during the first time period (and the second time period), or may be turned off or change to a sleeping mode. For example, in some embodiments, no system light may be provided at all for at least 6 hours after the second time period.

[0036] Thus, in particular, the operational mode includes a first time period during which system light is provided and a second time period during which system light is provided, and (i) the spectral power distribution and (ii) the radiant flux of the system light in the first time period and the second time period may be different.

[0037] Thus, in an embodiment, the light-generating system may be configured to provide (in an operational mode) system light according to the following characteristics: (a) during a first time period t1, the system light is light having a radiant flux Φ11 in a first wavelength range and a radiant flux Φ12 in a second wavelength range, in particular white light, and (b) during a second time period t2, the system light is light having a radiant flux Φ21 in a first wavelength range and a radiant flux Φ22 in a second wavelength range. Furthermore, in particular the following characteristics may apply: Φ21<Φ11 and Φ22>Φ12. In particular, in an embodiment, the first time period may be at least 15 minutes, such as at least about 30 minutes. Furthermore, in an embodiment, t2 may be selected from the range of 1 second to 30 minutes, more particularly at least about 30 seconds. If the radiant flux Φ22 in the second wavelength range during the second time period t2 is high, the second time period can be shorter, whereas if the radiant flux Φ22 in the second wavelength range during the second time period t2 is relatively low, the second time period may need to be longer, however, in particular t1>t2.

[0038] In a particular embodiment, the first wavelength range is 380 nm to λ1, and the second wavelength range is λ1 to 780 nm, where λ1 is selected from the range of 485 to 550 nm. Thus, in the present invention, the spectral power distribution may be divided into two parts, namely, the wavelength range between 380 nm and λ1, and the wavelength range between λ1 and 780 nm.

[0039] After the booster light during the second time period, there may still be a system light during a third time period. In general, its radiant flux will be less than the radiant flux during the first time period. For example, the radiant flux (within the wavelength range of 380-780 nm) during the third time period may be at least 10% lower, such as at least about 15% lower than during the first time period, or even lower, such as at least 50% lower than during the first time period. Alternatively or additionally, the system light during the third time period may have a lower CCT than the system light during the first time period. For example, the CCT may be at least 500K lower, such as at least 1000K lower. As also shown below, in some embodiments, after the second time period, the system light may be essentially turned off (thus there is no third time period). A lower radiant flux and / or a lower CCT during the third time period may reduce possible adverse effects on circadian rhythms.

[0040] In particular, t1+t2+t3≦24 hours. For example, t1+t2+t3≦16 hours. In some embodiments, t1+t2+t3≧2 hours. Furthermore, in some embodiments, t1≧t2+t3 may apply.

[0041] Thus, in a particular embodiment, the light-generating system may be configured to provide (in an operational mode) system light according to the following characteristics: (a) during a first time period t1, the system light is light, in particular white light, having a radiant flux Φ11 in a first wavelength range and a radiant flux Φ12 in a second wavelength range; (b) during a second time period t2, the system light is light having a radiant flux Φ21 in a first wavelength range and a radiant flux Φ22 in a second wavelength range; and (c) during a third time period t3, the system light is light having a radiant flux Φ31 in a first wavelength range and a radiant flux Φ32 in a second wavelength range. Furthermore, in particular the following characteristics may also apply: Φ21<Φ11 and Φ31<Φ11. Still further, in particular the following characteristics may also apply: Φ22>Φ12 and Φ32<Φ12. In particular, as also indicated above, t2 may be selected from the range of 1 second to 30 minutes, in particular t1>t2. Furthermore, as described above, the first wavelength range is from 380 nm to λ1, and the second wavelength range is from λ1 to 780 nm, where λ1 is selected from the range of 485 to 550 nm.

[0042] The term "white light" and similar terms herein are known to those skilled in the art. It may particularly relate to light having a correlated color temperature (CCT) between about 1800K and 20000K, such as between 2000K and 20000K, particularly 2700-20000K, and particularly for general illumination, a CCT in the range of about 2000-7000K, such as in the range of 2700K and 6500K. In some embodiments, for example for backlighting purposes or other purposes, the CCT may particularly be in the range of about 7000K and 20000K. Still further, in some embodiments, the CCT is particularly within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), particularly within about 10 SDCM from the BBL, and more particularly within about 5 SDCM from the BBL. As will be further elucidated below, the CCT herein may be selected, inter alia, from the range of 2000-6500K, for example from the range of 2000-4000K. It is further noted that in some embodiments, the CCT may vary over time, such as a higher CCT during a first time period and a lower CCT during an (optional) third time period. In some embodiments, the CCT of the system light may also be lower during a second time period when compared to the CCT of the system light during the first time period.

[0043] As mentioned above, the system light during the first time period may be white light. However, in other specific embodiments, the system light during the first time period is visible light but not white light. In particular, in some embodiments, Φ11 / Φ12≧0.001, more particularly, in some embodiments, Φ11 / Φ12≧0.005. In some embodiments, 0.001≦Φ11 / Φ12<1, such as 0.005≦Φ11 / Φ12≦0.5. If Φ11 is zero, then generally Φ21 may also be zero. However, generally, in this specification, Φ11 / Φ12≧0.001.

[0044] 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 specifically refer to wavelengths selected from the range of 190-380 nm, such as 200-380 nm. The terms "light" and "radiation" are used interchangeably in this specification, 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 terms "violet light" or "violet emission" and similar terms may specifically refer to light having a wavelength in the range of about 380-440 nm. In certain embodiments, the ultraviolet light may have a centroid wavelength in the range of 380-440 nm. The terms "blue light" or "blue emission" and similar terms may particularly refer to light having a wavelength in the range of about 440-490 nm (including some purple and cyan hues). In certain embodiments, the blue light may have a centroid wavelength in the range of 440-490 nm. The terms "green light" or "green emission" and similar terms may particularly refer to light having a wavelength in the range of about 490-560 nm. In certain embodiments, the green light may have a centroid wavelength in the range of 490-560 nm. The terms "yellow light" or "yellow emission" and similar terms may particularly refer to light having a wavelength in the range of about 560-590 nm. In certain embodiments, the yellow light may have a centroid wavelength in the range of 560-590 nm.The term "orange light" or "orange emission" and similar terms may particularly refer to light having a wavelength in the range of about 590-620 nm. In certain embodiments, the orange light may have a centroid wavelength in the range of 590-620 nm. The term "red light" or "red emission" and similar terms may particularly refer to light having a wavelength in the range of about 620-750 nm. In certain embodiments, the red light may have a centroid wavelength in the range of 620-750 nm. The term "cyan light" or "cyan emission" and similar terms may particularly refer to light having a wavelength in the range of about 490-520 nm. In certain embodiments, the cyan light may have a centroid wavelength in the range of 490-520 nm. The terms "amber light" or "amber emission" and similar terms may particularly refer to light having a wavelength in the range of about 585-605 nm, such as about 590-600 nm. In certain embodiments, the amber light may have a centroid wavelength in the range of 585-605 nm.

[0045] The term "centroid wavelength", also denoted as λc, is known in the art and refers to the wavelength value where half of the light energy is at short wavelengths and half of the light energy is at long wavelengths, the value being stated in nanometers (nm). It is the wavelength that bisects the integral of the spectral power distribution, as expressed by the formula λc=Σλ*I(λ) / (ΣI(λ), where the summation is over the wavelength range of interest and I(λ) is the spectral energy density (i.e., the integration of the wavelength-intensity product over the emission band normalized by the integrated intensity). The centroid wavelength may be determined, for example, at operating conditions.

[0046] The phrase "light having one or more wavelengths in a wavelength range" and similar phrases may specifically indicate that the indicated light (or radiation) has a spectral power distribution having at least an intensity(s) at those one or more wavelengths in the indicated wavelength range. For example, a blue-emitting solid-state light source will have a spectral power distribution having an intensity at one or more wavelengths in the wavelength range of 440-495 nm.

[0047] In one embodiment, to effect, R 22,12 ≧1.05 and R 22,12 =Φ22 / Φ12. Furthermore, to obtain an (enhanced) effect, it is desirable to simultaneously 21,11 ≦0.9 and R 21,11 =Φ21 / Φ11. Therefore, in one embodiment, R 21,11 =Φ21 / Φ11, and R 22,12 =Φ22 / Φ12, and R 21,11 ≦0.9, and R 22,12 ≧1.05.

[0048] The radiant flux decrease below λ1 (during the second time period) may be evenly distributed across the spectral power distribution below λ1. In alternative embodiments, the radiant flux decrease below λ1 (during the second time period) may not be evenly distributed across the spectral power distribution below λ1. For example, one or more portions of the spectral power distribution below λ1 may be decreased more than one or more other portions, or even more than one or more other portions (collectively R 21,11 <1), one or more portions of the spectral power distribution below λ1 may be increased, while one or more other portions may be decreased.

[0049] The radiant flux increase above λ1 (during the second time period) may be evenly distributed across the spectral power distribution above λ1. In alternative embodiments, the radiant flux increase above λ1 (during the second time period) may not be evenly distributed across the spectral power distribution above λ1. For example, one or more portions of the spectral power distribution above λ1 may increase more than one or more other portions, much less than R 22,12 >1), one or more portions of the spectral power distribution above λ1 may decrease while one or more other portions may become more increased. Thus, the increase in radiant flux during the second time period within the wavelength range above λ1 and / or the decrease in radiant flux during the second time period within the wavelength range below λ1 may be expressed as R 21,11 <1, more specifically R 21,11 ≦0.9, and R 22,12 >1, more specifically R 22,12 It may be selected to be ≧1.05.

[0050] In the case of a wavelength λ1 selected from the range of about 485 to 550 nm and a CCT of a system light selected from the range of about 2000 to 6500 K, particularly selected from the range of 2000 to 4000 K, R 22,12 may in some embodiments be up to about 5. Higher values ​​may be possible, especially at higher CCTs and / or higher values ​​of λ1 wavelength (see also below). Thus, values ​​of λ1 wavelength greater than 550 nm may be less desirable. Furthermore, R 22,12 can be relatively high, so a CCT of no higher than about 6500K, such as no higher than 5000K, may be desirable.

[0051] In some embodiments, particularly at the higher wavelengths of λ, R 22,12 may take on values ​​greater than 5, for example greater than 10. This is especially true for R 21,11 It may be the case that R is chosen to be high (but still below 1). 22,12may be less desirable since a sudden large increase in intensity may not always be appreciated by the user. Thus, in particular in certain embodiments, λ and R 21,11 is 1.05≦R 22,12 ≦7, more particularly 1.05≦R 22,12 ≦5. In particular, in some embodiments, 1.05≦R 22,12 ≦4. Therefore, in particular, R 22,12 ≦7, more particularly R 22,12 ≦5, e.g. R 22,12 <=4.

[0052] In a more specific embodiment, when λ1 is selected from the range of 485 to 500 nm, 1.05≦R 22,12 ≦3.0 may apply, and when λ1 is selected from the range of 500 to 550 nm, (2.2≦R 22,12 ≦4 etc.)2.2≦R 22,12 ≦5 may apply. However, as indicated above, other values ​​are possible, but in particular at least the following may apply: R 21,11 <1 and R 22,12 >1, more specifically R 21,11 ≦0.9 and R 22,12 ≧1.05 (may apply).

[0053] In certain embodiments, R 21,11 ≦0.8. Furthermore, in certain embodiments, R 21,11 = 0. The former embodiment, but especially the latter embodiment, may lead to colored system light during the second period. 21,11 value and relatively small R 22,12 In value, the system light during the second time period may be white light, however, as will be further elucidated below, the system light during the second time period may be colored light.

[0054] In an embodiment, the increase in the (second) radiant flux during the second time period in the wavelength range above λ1 may be relatively smaller than the decrease in the first radiant flux in the wavelength range below λ1. 22,12 Since it may already be possible to obtain the desired effect with relatively small changes in R 22,12 It may be desirable to use smaller values ​​of λ. Thus, although a large increase in the radiant flux above λ is not precluded, it may not be necessary, especially if λ is not chosen too high.

[0055] In certain embodiments, R 21,11 *R 22,12 For example, in one embodiment, R 21,11 *R 22,12 ≦4, for example, in further particular embodiments, R 21,11 *R 22,12 <= 2.

[0056] At values ​​of λ1 less than about 485 nm, the effect may be relatively small, and at values ​​of λ1 greater than about 550 nm, the effect may be reduced and / or the radiant flux (R 22,12 ) and / or the benefit may be obtained at lower CCTs only during the first time period. Thus, in certain embodiments, λ1 may be selected from the range of about 490-530 nm.

[0057] The higher λ1, the higher R 22,12 It may be desirable to increase the split wavelength λ1. This may lead to impractical situations (i.e., not feasible for indoor light sources). Furthermore, the higher the split wavelength λ1, the smaller the reduction in % of active melanopsin pigment may be. From an efficiency standpoint, the split wavelength may be selected to be as low as possible, in particular at least not greater than 530 nm.

[0058] In some embodiments, the selection of split wavelength λ1 can be based on considerations regarding, for example, the upper emitting wavelength of the blue primary light source. When using this split wavelength, the intensity change for wavelengths < λ1 may be achieved by dimming the blue primary.

[0059] Furthermore, in certain embodiments, the system light during the first time period t1 may have a correlated color temperature selected from the range of 2000 to 6500 K, more particularly selected from the range of 2000 to 4000 K. Thus, in particular, the system light during the first time period may be white light, in particular white light having a color within 15 SDCM from the blackbody locus. However, in other embodiments, the system light may be colored light.

[0060] In particular, the spectral power distribution of the system light during the first time period may differ from the spectral power distribution of the system light during the second time period. In particular embodiments, the colors or color points of the first type of light and the second type of light may differ if the respective color points of the first type of light and the second type of light differ by at least 0.01 for u' and / or at least 0.01 for v', even more particularly by at least 0.02 for u' and / or at least 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 least 0.03 for u' and / or at least 0.03 for v', where u' and v' are the color coordinates of the light in the CIE 1976 UCS (uniform chromaticity scale) diagram. Spectral power distributions of different light sources whose centroid wavelengths differ by at least 10 nm, such as at least 20 nm, or even at least 30 nm, may be considered as different spectral power distributions, e.g., different colors. Generally, the difference in centroid wavelengths will not be greater than about 400 nm, such as 350 nm or less.

[0061] In some embodiments, the light-generating system may include at least two (i.e., two or more) light-generating devices configured to generate device lights having different spectral power distributions. In this manner, the spectral power distribution and radiant flux(es) of the system light may be controlled by controlling the at least two light-generating devices. Thus, in some embodiments, the one or more light-generating devices include (i) a first light-generating device configured to generate a first device light and (ii) a second light-generating device configured to generate a second device light, where the spectral power distributions of the first device light and the second device light are different, and the system light includes one or more of the first device light and the second device light.

[0062] In an embodiment, one of the two or more light-generating devices may be configured to generate white light having a relatively low content of one or more of green light, yellow light, orange light, and red light, and another of the two or more light-generating devices may be configured to generate white light having a relatively high content of one or more of green light, yellow light, orange light, and red light.

[0063] In some embodiments, one of the two or more light-generating devices may be configured to generate white light, while another of the two or more light-generating devices may be configured to generate colored light having a relatively high content of one or more of green light, yellow light, orange light, and red light.

[0064] In an embodiment, one of the two or more light-generating devices may be configured to generate colored light, in particular having one or more wavelengths in the blue wavelength range and / or having one or more wavelengths in the green wavelength range, and another of the two or more light-generating devices may be configured to generate colored light having a relatively high content of one or more of green light, yellow light, orange light, and red light, while together they may provide white light in an operational mode.

[0065] In certain embodiments, the first device light may be a cool white light and the second device light may be a warm white light, and during the second time period t2, the contribution of the second device light to the system light may be greater than during the first time period t1. The advantage of combining cold white light and warm white light is that the light generating system provides system light that is useful for pre-sleep human activities that require acceptable white light conditions or sleep preparation human activities that require acceptable white light conditions at any time without interfering with human melatonin production in the evening and before sleep. Such human activities include, for example, winding down, reading in bed, brushing teeth before sleep, walking to the bedroom, loading a night-time dishwasher, etc.

[0066] In an (alternative) particular embodiment, the first device light may be cool white light and the second device light may be colored light having one or more wavelengths in at least one of a yellow wavelength range, an orange wavelength range, and a red wavelength range, and during the second time period t2, a contribution of the second device light to the system light may be greater than during the first time period t1.

[0067] Of course, the above examples may refer to two (or more) sets of light-generating devices, where the light-generating devices in a set may be configured to generate device light having essentially the same spectral power distribution, and where the light-generating devices from different sets may be configured to generate device light having different spectral power distributions. Each set may include at least one light-generating device. The control system may be configured to control the sets individually.

[0068] In certain embodiments, the second device light may be colored light having a centroid wavelength λ2 selected from the range λ1<λ2≦780 nm, such as selected from the range λ1<λ2≦650 nm.

[0069] In particular, in an embodiment, the first device light may be white light and the second device light may be colored light having a centroid wavelength λ2 selected from the range of λ1<λ2≦650 nm. For example, the second device light may be green light, yellow light, orange light, or red light. More particularly, the second light may be green light or yellow light. Thus, in a particular embodiment, the second device light may have a centroid wavelength λ2 selected from the range of λ1<λ2≦550 nm.

[0070] If the system light is colored light during the first time period and colored light during the second time period, a centroid wavelength of the system light during the first time period may be smaller than during the second time period.

[0071] The ratio of Φ31 / Φ11 is R 31,11 In some embodiments, t3 is not equal to 0 minutes and R 31,11 <1. In particular, in one embodiment, R 31,11 ≦0.5. The ratio of Φ32 / Φ12 is R 32,12 In some embodiments, where t is not equal to 0 minutes, R 32,12 <1. In particular, in one embodiment, R 32,12 ≦0.5.

[0072] In one embodiment (t3 not equal to 0 minutes), the spectral power distribution of the system light during the first time period and the third time period is the same (however, the radiant flux is different). In an alternative embodiment (t3 not equal to 0 minutes), the spectral power distribution of the system light during the second time period and the third time period is the same (however, the radiant flux is different).

[0073] Note that in an alternative embodiment, t3 may be 0 minutes, and thus Φ31 and Φ32 may be zero.

[0074] In an embodiment, the system provides at least 100 lux, such as at least 250 lux, such as at least 500 lux, incident on a surface per unit area (1 m 2 The system may be configured to generate a system light having an illuminance, defined as luminous flux per 100 Hz, during a second period of time.

[0075] In an embodiment (where t is not equal to 0 minutes), the system may provide up to 100 lux, such as up to 50 lux, particularly up to 10 lux, incident on a surface per unit area (1 m 2 ) during a third time period.

[0076] In some embodiments, the illuminance value of the system light (expressed in "lux") during the second time period t2 is equal to or greater than the illuminance value of the system light during the first time period t1, preferably greater than the illuminance value of the system light during the first time period t1. That is, in such an embodiment, the system light has a variable illuminance value E v and a variable illuminance value E of the system light during a second time period t2. v is the illuminance value E of the system light during the first time period t1 v or the illuminance value E of the system light during the first time period t1 v Of course, the same relationship applies to the luminous flux or luminous power of the system light (expressed in "lumens"). This is highly counterintuitive, since general teaching is to turn down light intensity before sleep, not turn it up.

[0077] In one embodiment, the variable illuminance value E of the system lightv and variable melanopic equivalent daylight illuminance value E v,mel D65 is greater during the second time period t2 than during the first time period t1. Therefore, in one embodiment, the system light has a variable illuminance value E v and variable melanopic equivalent daylight illuminance value E v,mel D65 (i) a variable illuminance value E of the system light; v and (ii) a variable melanopic equivalent daylight illuminance value, E v,mel D65 is greater during the second time period t2 than during the first time period t1. Thus, in one embodiment, the variable melanopic equivalent daylight illuminance value E of the system light during the second time period t2 v,mel D65 may be equal to or greater than during the first time period t1. Furthermore, in some embodiments, the variable illuminance value E of the system light v and variable melanopic equivalent daylight illuminance value E v,mel D65 are smaller during the third time period t3 than during the first time period t1 and / or the second time period t2.

[0078] The system light during the second time period t2, also called boost pulse, may be provided for a relatively short period of time. For example, such a boost pulse may be provided just before going to sleep and may last, for example, up to about 30 minutes. The time may depend on the radiant flux. In general, the higher the radiant flux of the system light during the second period, the shorter the second period may be. Thus, the lower the radiant flux of the system light during the second period, the longer the second period may be selected. In an embodiment, t2 may be selected from a range of at least 30 seconds, such as selected from a range of 1 to 15 minutes. In particular, the second time period may not be longer than 60 minutes, such as not longer than 30 minutes.

[0079] The first time period may be essentially any time period, but in particular may be no longer than about 20 hours, such as no longer than about 16 hours. In an embodiment, t1 may be at least 1 hour, such as at least about 1.5 hours. For example, t1 may be selected from a range of 30 minutes to 8 hours, such as 1 to 6 hours. For example, t1 may be a period selected within a time frame of 17:00 to 24:00 hours. In particular, the first time period may be a period during dusk.

[0080] In an embodiment, the boost pulse may be provided during a period before entering sleep when the system light is provided, thereby dividing the period into two (or effectively three) periods, with the time preceding the boost pulse being the first period and the time following the boost pulse being the third period. The optical properties such as the spectral power distribution and the radiant flux during the first and third time periods may be the same, but may also be different. In particular, as also indicated above, the radiant flux may be lower and / or the CCT may be lower for the system light during the third period compared to the first period. Thus, the third period may in particular be the period immediately prior to entering sleep.

[0081] In some embodiments, t3 may be up to 2 hours. Too long a period may have a detrimental effect on the effect of the boost pulse. Thus, in some embodiments, t3 may be selected from the range of 0 to 60 minutes, such as 0 to 45 minutes, and may be, for example, at least about 10 minutes in some embodiments. In particular, in some embodiments, t1>t3. Furthermore, in other embodiments, t3 is 0 minutes. In alternative embodiments, t3>0 minutes, such as t3>t2 in some embodiments. However, in further alternative embodiments, t2>t3. In particular, however, as indicated above, t3≦60 minutes, more particularly t3≦30 minutes, such as t3≦15 minutes, such as 0 to 15 minutes. The shorter the third time period, the higher the continued effect of the booster light pulse during the second time period may be.

[0082] As indicated above, the system may further include a control system configured to control the system light depending on one or more of the input signal of the user interface, the sensor signal (of the sensor), and the timer. In an embodiment, the sensor may be at least configured to generate a sensor signal depending on a parameter related to human behavior. The sensor may be selected from a motion sensor, a presence sensor, a sound sensor, a light sensor, etc. Thus, the control system may learn the behavior of a human using the system based on the sensor signal. For example, routines such as turning on the dishwasher, turning off certain lights, dimming the lights, using the stairs, using the bathroom, brushing teeth, etc., combined with time, may lead to a recognizable pattern. In such an embodiment, the system may determine a moment when a person would like to fall asleep and provide a boost pulse at the calculated time. Thus, in an embodiment, the system may be a self-learning system.

[0083] In an embodiment, the system may include two or more light-generating devices, at least two of which (of the two or more light-generating devices) may be configured in different rooms. This may even allow providing the system light during the first period and the system light during the second period (and the system light during the third period) at spatially different locations. Thus, in an embodiment, the first light-generating device and the second light-generating device may be configured in different spaces (within a building), the first light-generating device may be configured to generate (white) system light during a first time period t1 with a radiant flux Φ11 in a first wavelength range and a radiant flux Φ12 in a second wavelength range, and the second light-generating device may be configured to generate system light during a second time period t2 with a radiant flux Φ21 in a first wavelength range and a radiant flux Φ22 in a second wavelength range. In an embodiment, the space in which the first light-generating device is configured may be selected from a living room and a kitchen, and the space in which the second light-generating device is configured may be selected from a bathroom, a toilet, and a sleeping room.

[0084] The system may further include a third light-generating device configured in a space different from the first space in which the first light-generating device is configured and optionally different from the second space in which the second light-generating device is configured. In an embodiment, the space in which the third light-generating device may be configured is selected from a bathroom, a toilet, and a sleeping room, and in particular, the third light-generating device may be configured in a sleeping room. In a particular embodiment, three spatially differently configured light-generating devices may be configured to generate system light during the three mentioned time periods in different spaces, respectively. In yet another particular embodiment, two spatially differently configured light-generating devices may be configured to generate system light during the first time period and the second time period in different spaces, respectively.

[0085] The light producing system may be part of or applied to, for example, a home lighting system, an accent lighting system, a spot lighting system, a fiber optic application system, a projection system, a self-emissive display system, a pixelated display system, a segmented display system, a decorative lighting system, etc.

[0086] In yet a further aspect, the present invention also provides one or more lamps or luminaires comprising a light-generating system as defined herein. The one or more luminaires may further comprise a housing, optical elements, louvers, etc. The one or more lamps or luminaires may further comprise a housing enclosing the light-generating system. The one or more lamps or luminaires may comprise an optical window or housing opening in the housing through which the system light may escape the housing. In still a further aspect, the present invention also provides one or more projection devices comprising a light-generating system as defined herein. In particular, a projection device or "projector" or "image projector" may be an optical device that projects an image (or moving image) onto a surface, such as a projection screen. The one or more projection devices may comprise one or more light-generating systems as described herein. Thus, in one aspect, the present invention also provides a light-generating device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising a light-generating system as defined herein. The light-generating device may include a housing or carrier configured to house or support one or more elements of the light-generating system. For example, in some embodiments, the light-generating device may include a housing or carrier configured to house or support one or more light-generating devices.

[0087] In a still further aspect, the present invention also provides a method for generating system light (i.e. light provided by a light-generating system, in particular a light-generating system as described herein), the method comprising: (a) generating, during a first time period t1, system light, in particular white system light, having a radiant flux Φ11 in a first wavelength range and a radiant flux Φ12 in a second wavelength range; (b) generating, during a second time period t2, system light, having a radiant flux Φ21 in the first wavelength range and a radiant flux Φ22 in the second wavelength range. and (c) optionally during a third time period t3, generating system light having a radiant flux Φ31 in a first wavelength range and a radiant flux Φ32 in a second wavelength range, where Φ21<Φ11, and Φ31<Φ11, Φ22>Φ12, and Φ32<Φ12, t2 is selected from the range of 1 second to 30 minutes, t1>t2, the first wavelength range is from 380 nm to λ1, the second wavelength range is from λ1 to 780 nm, and λ1 is selected from the range of 485 to 550 nm.

[0088] As indicated above, the third stage of generating system light during a third time period t3 is optional. If available, t3>0 minutes (especially at least 1 second, etc.), if this stage is not available, t3=0 minutes (effectively t3=0 seconds). Thus, the phrase "optionally during a third time period t3" and similar phrases may refer to an embodiment in which t1 and t2 are not equal to 0 minutes, and t3 may be 0 minutes or greater than 0 minutes (but in particular 2 hours or less, more in particular 1 hour or less (see also above)). If t3=0 minutes, then of course the radiant flux Φ31 in the first wavelength range and the radiant flux Φ32 in the second wavelength range are also zero. [Brief description of the drawings]

[0089] Embodiments of the 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, and in which the drawings are not necessarily to scale. [Figure 1a]Figure 1a shows diagrammatically the tri-stability of melanopsin (see also Emanuel et al., infra). Photoconversion can only occur between R and M, and between M and E. In particular, the pigment fraction (at photo-equilibrium) upon stimulation with monochromatic light is plotted. On the y-axis the fractions of the three pigment states are shown diagrammatically. The sum of the three fractions should equal 1. [Figure 1b] Figure 1b shows a numerical simulation of the melanopsin pigment fraction in the signaling M state. In this example, the light spectrum changes from (a) 4000K office light to (b) 2700K or (c) 2000K evening light at 18:00. [Figure 1c] Figure 1c shows a simulation of a change in illumination, here at 23:00, from 2700 K (a) to 525 nm light, resulting in a large decrease in the M-state pigment fraction. Note that the decrease is achieved faster when 500 lux (c) is used instead of 100 lux (b). [Diagram 2] FIG. 2 illustrates a schematic of one embodiment of a light-producing system. [Figure 3a] Figure 3a shows a schematic case of adapting a user to evening light at 2700K, indicated by the dashed line in the graph. 500 nm was chosen as the wavelength λ1 at which the light spectrum is "splitted". To create a light boost to improve sleep onset, the intensity of wavelengths with split wavelengths > (λ1>) is reduced and the intensity of wavelengths with split wavelengths < (λ1<) is increased. [Figure 3b] FIG. 3b shows a schematic representation of a possible time-dependent radiant flux. [Figure 3c] FIG. 3c shows an example of the multiplication factor, here for an embodiment with system light having a CCT of 2700K and λ1=500 nm in a first time period. [Figure 4a] FIG. 4a shows a further (application) embodiment diagrammatically. [Figure 4b] FIG. 4b shows a further (application) embodiment diagrammatically. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0090] Current lighting applications ignore the reported findings that melanopsin pigments have been shown to be tri-stable, as described by Emanuel et al. in Melanopsin tristability for sustained and broadband phototransduction, Neuron, 2015, 85(5), 1043-1055, doi:10.1016 / j.neuron.2015.02.011, which is incorporated herein by reference. When stimulated by light, the process of photo-conversion (isomerization) can disperse melanopsin pigments into three states (two silent and one signaling). This is shown diagrammatically in FIG. 1a, labeled R, M, and E. Only the fraction of melanopsin in the signaling state (M) can contribute to the phototransduction process of ipRGCs. Thus, it can be expected that the strength of the signal sent from ipRGCs to the SCN (the signal to the brain) depends on this melanopsin fraction.

[0091] Each time the spectral composition of the light reaching the melanopsin photopigment changes, the photoconversion process between the R and M states, and between the M and E states, reaches a new equilibrium. This can take time, depending on both the spectrum and the intensity of the light. The relative spectral distribution determines the pigment fraction at equilibrium, while the absolute intensity determines the speed of the process. With high-intensity light, this can be a few seconds, while low-intensity light can require several hours to reach this equilibrium point. Emanuel et al. demonstrated many white light sources in their ability to alter the pigment fraction. The broadband white light source selected by Emanuel et al. was found to maintain a more or less stable pigment fraction. Furthermore, stimulation with monochromatic light appears to be able to alter the fraction considerably.

[0092] The present invention provides a novel and more optimized way of controlling the sensitivity of the melanopsin system by light, in particular by taking into account the fraction of "signaling" melanopsin pigments, as opposed to darkness, which may seem counterintuitive. Specifically, the application of short-duration, intense light to quickly force a fraction of the melanopsin signaling state into silence is described herein. This approach may seem counterintuitive, since more light (higher lux level) is used (temporarily) to reduce melanopsin activation, rather than less light. The short-duration, intense light can also be extended to a longer-duration, less intense light, if this is more convenient for the end user. In this case, the duration of the shift of tristable melanopsin to the silent state will take longer, but it will still be more silent than the regular white and dim light conditions that are usually used.

[0093] Figure 1b shows an example where a change in lighting at 18:00 is simulated, from a standard office lighting spectrum (4000K, 500 lux) to typical evening lighting in the home. For the latter, 2700K or 2000K at 100 lux are used. The simulation shows that the pigment fraction is reduced from 0.51 to 0.48 and 0.45 respectively by changing the CCT to lower values, with a larger reduction for 2000K light. It is expected that the lower this fraction is, the faster people can fall asleep due to a reduced suppression of melatonin production in the pineal gland.

[0094] The magnitude of the reduction in the pigment fraction, and the speed at which this occurs, depends entirely on the spectrum and intensity of the light. It seems that longer wavelengths may require (substantially) more time compared to shorter wavelengths. However, for the present purpose of forcing / keeping a low pigment fraction in the M state, shorter wavelengths should not be used (see also FIG. 1a). Thus, how much the fraction can be reduced may depend on the choice of wavelength used and the time available to the user.

[0095] In Fig. 1c, an example is shown where a large reduction (from 0.48 to about 0.3) can be obtained using light of wavelength 525 nm. This example also shows that the reduction is obtained more quickly if the lux level is increased from 100 lux to 500 lux, which is totally counter-intuitive. Roughly, a factor of 10 increase in illuminance makes the process 10 times faster. Simulations show that the pigment fraction can be significantly reduced by the present invention from 0.48 to 0.3, which in itself is a very effective solution for preparing people to fall asleep, assuming that the user turns off all bedroom lights within a reasonably short time after the light intervention.

[0096] With reference to Figures 2-3, several aspects and embodiments are (schematically) illustrated.

[0097] FIG. 2 shows a schematic representation of one embodiment of a light-generating system 1000. However, many other embodiments are possible within the scope of the claims. The light-generating system 1000 comprises one or more light-generating devices 100. Each of the one or more light-generating devices 100 is configured to generate a device light 101. The light-generating system 1000 may be configured to generate a system light 1001 comprising the device light 101 of at least one light-generating device 100. The light-generating system 1000 may be configured to provide (in an operational mode) the system light 1001 according to one or more, in particular all, of the following characteristics: (a) during a first time period t1, the system light 1001 may be (white) light having a radiant flux Φ11 in a first wavelength range and a radiant flux Φ12 in a second wavelength range; (b) during a second time period t2, the system light 1001 may be light having a radiant flux Φ21 in a first wavelength range and a radiant flux Φ22 in a second wavelength range; (c) During a third time period t3, the system light 1001 may be light having a radiant flux Φ31 in a first wavelength range and a radiant flux Φ32 in a second wavelength range, (d) Φ21<Φ11, Φ31<Φ11, (e) Φ22>Φ12, Φ32<Φ12, (f) t2 may be selected from the range of 1 second to 30 minutes, (g) t1>t2, (h) the first wavelength range may be 380 nm to λ1, and the second wavelength range may be λ1 to 780 nm, and (i) λ1 may be selected from the range of 485 to 550 nm.

[0098] In one embodiment, R 21,11 =Φ21 / Φ11, R 22,12 =Φ22 / Φ12, R 21,11 ≦0.9, and R 22,12 In some embodiments, 1.05≦R 22,12 ≦5. In particular, in an embodiment, when λ1 may be selected from the range of 485 to 500 nm, 1.05≦R 22,12≦3.0, and λ1 may be selected from the range of 500 to 550 nm, where 2.2≦R 22,12 In certain embodiments, R 21,11 *R 22,12 ≦5. In some embodiments, λ1 may be selected from the range of 490 to 530 nm. In some embodiments, the system light 1001 during the first time period t1 may have a correlated color temperature selected from the range of 2000 to 6500 K, more particularly selected from the range of 2000 to 4000 K.

[0099] 2 illustrates a schematic representation of an embodiment of a system 1000, in which the one or more light-generating devices 100 include (i) a first light-generating device 110 configured to generate a first device light 111, and (ii) a second light-generating device 120 configured to generate a second device light 121. In particular, the spectral power distributions of the first device light 111 and the second device light 121 may be different. In particular, the system light 1001 may include one or more of the first device light 111 and the second device light 121. Reference numeral 301 denotes a user interface, which may optionally be included in the system 1000.

[0100] In a particular embodiment, the first device light 111 may be a cool white light and the second device light 121 may be a warm white light, however other embodiments may be possible (see above and below).

[0101] Furthermore, in some embodiments, during the second time period t2, the contribution of the second device light 121 to the system light 1001 may be greater than during the first time period t1.

[0102] In an embodiment, the second device light 121 may be colored light having a centroid wavelength λ2 selected from the range λ1<λ2≦780 nm.

[0103] In a particular embodiment, the first device light 111 may be white light and the second device light 121 may be colored light having a centroid wavelength λ2 selected from the range λ1<λ2≦650 nm.

[0104] In particular, in one embodiment, the second device light 121 may have a centroid wavelength λ2 selected from the range λ1<λ2≦550 nm.

[0105] In one embodiment, the system light 1001 has a variable illuminance value E v and variable melanopic equivalent daylight illuminance value E v,mel d65 In particular, the variable illuminance value E of the system light 1001 v and variable melanopic equivalent daylight illuminance value E v,mel d65 may be greater during the second time period t2 than during the first time period t1.

[0106] In some embodiments, t2 may be selected from the range of 1 to 15 minutes. Alternatively or additionally, in some embodiments, t1 may be at least 1 hour. Further alternatively or additionally, t3 may be up to 2 hours. In certain embodiments, t1>t3.

[0107] 2, the light-generating system 1000 may further include a control system 300 configured to control the system light 1001 in dependence on one or more of a user interface input signal, a sensor signal (of a sensor), and a timer. In an embodiment, the sensor 310 may be at least configured to generate a sensor signal in dependence on a parameter related to human behavior.

[0108] 3a shows a schematic of the spectral power distribution of the system light 1001, where λ1 is about 500 nm, the dashed curve is the spectral power distribution during a first time period, and the solid curve is the spectral power distribution during a second time period, where the intensity at all wavelengths below λ1 is selected to be decreased and the intensity at all wavelengths above λ1 is selected to be increased.

[0109] In alternative embodiments, the radiant flux reduction below λ (during the second time period) may not be evenly distributed across the spectral power distribution below λ. For example, one or more portions of the spectral power distribution below λ may be reduced more than one or more other portions, much less than R (as a whole). 21,11 <1), one or more portions of the spectral power distribution below λ1 may increase while one or more other portions decrease more. Similarly, in alternative embodiments, the radiant flux increase above λ1 (during the second time period) may not be evenly distributed across the spectral power distribution above λ1. For example, one or more portions of the spectral power distribution above λ1 may increase more than one or more other portions, much less than the overall (such that R 22,12 >1), one or more portions of the spectral power distribution above λ may be decreased while one or more other portions may be increased. 21,11 =Φ21 / Φ11, R 22,12 =Φ22 / Φ12, R 21,11 ≦0.9, and R 22,12 ≧1.05.

[0110] Figure 3b shows by way of example some possible radiation fluxes over time: The booster light pulse Φ22 is clearly visible in the second time period t2.

[0111] For different intensity reduction factors (for the split wavelength>), the minimum required multiplication factor for the split wavelength< to produce an optical boost was determined.

[0112] The table below and Fig. 3c show an exemplary curve for 2700K, λ1=500nm. In the table below some further results of the multiplication factor are provided, where λ1 denotes the wavelength at which the spectral power distribution is divided into a below (<λ1) and above (>λ1) part. Values ​​at different CCTs are provided. The multiplication factor is determined for a booster light pulse time of 5 minutes. TIFF2025514852000002.tif58168TIFF2025514852000003.tif120163TIFF20255148520 00004.tif128168TIFF2025514852000005.tif208165TIFF2025514852000006.tif137169

[0113] The above table is directed to an embodiment where the system light during the first time period is white light. For colored light during the first time period, the same multiplication factors may be applied.

[0114] From the above table, it seems that at higher CCT and larger split wavelengths, even the minimum multiplication factor or ratio R22,12 can be greater than 5 (see for example split wavelength of 550 nm, where for one entry the minimum ratio R22,12 is 15.6). If one wishes to stay below the value of 5, the multiplication factor for the lower wavelength range (<λ1) may be adapted and / or the split wavelength may be adapted (i.e., in this example of 550 nm, lowered below 550 nm). It should be noted that, as mentioned before, 550 nm is in any case a relatively large wavelength. In particular, λ1 may be selected from the range of 490 to 530 nm.

[0115] FIG. 4a shows a schematic representation of an embodiment of a lighting fixture 2 including the light-generating system 1000 described above. Reference number 301 indicates a user interface that may be included in the light-generating system 1000 or functionally coupled to a control system 300 that is functionally coupled to the light-generating system 1000. FIG. 4a also shows a schematic representation of 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, such as on a wall, and that may also include the light-generating system 1000. Thus, FIG. 4a shows a schematic representation of an embodiment of a lighting device 1200 selected from the group of lamps 1, lighting fixtures 2, projector devices 3, disinfection devices, photochemical reactors, and optical wireless communication devices, including the light-generating system 1000 described herein. In some embodiments, such lighting devices may be lamps 1, lighting fixtures 2, projector devices 3, disinfection devices, or optical wireless communication devices. Illumination device light escaping from the illumination device 1200 is indicated with reference numeral 1201. The illumination device light 1201 may consist essentially of the system light 1001, and thus may be the system light 1001 in certain embodiments.

[0116] Referring to FIG. 4b, the light-generating system 1000 may include a first light-generating device 110 and a second light-generating device 120, which may be arranged in different spaces. The first light-generating device 110 may be configured to generate a white system light 1001 having a radiant flux Φ11 in a first wavelength range and a radiant flux Φ12 in a second wavelength range during a first time period t1. The second light-generating device 120 may be configured to generate a system light 1001 having a radiant flux Φ21 in a first wavelength range and a radiant flux Φ22 in a second wavelength range during a second time period t2. The first light-generating device 110 may be arranged in a space selected from a living room and a kitchen. The second light-generating device 120 may be arranged in a space selected from a bathroom, a toilet, and a bedroom. The different spaces 1300 are indicated by reference numbers 1310, 1320, and 1330, respectively. Of course, three or more different spaces may be illuminated with the device light of one or more light-generating devices. In embodiment I of Fig. 4b, the first light-generating device 110 is arranged in the living room 1310. Furthermore, the second light-generating device 120 is also arranged in the living room 1310, but the second light-generating device may be arranged in the bedroom 1320 and / or the toilet 1330. This may allow a booster pulse in the living room and, optionally, the system light 1001 at reduced intensity and / or reduced CCT in the bedroom 1320 and / or the toilet 1330 during the third time period. However, this may also allow a booster pulse in the bedroom 1320 and / or the toilet 1330 and, optionally, the system light 1001 at reduced intensity and / or reduced CCT in the bedroom 1320 and / or the toilet 1330 during the third time period. In embodiment I, the system light 1001 in the living room 1310 may be provided by contributions from both the first device 110 and the second device 120, whereas in embodiment II of FIG. 4b, the system light 1001 in the living room 1310 may be provided only by the device light 111.In such an embodiment, for example, a booster pulse in the bedroom 1320 and / or toilet 1330 may be provided, and optionally, system light 1001 may be provided at a reduced intensity and / or reduced CCT in the bedroom 1320 and / or toilet 1330 during a third period.

[0117] In particular, the present invention provides a lighting system in which at least one light setting is applied before sleep onset, providing a "high intensity" setting, for example with a dominant wavelength of 485 nm or greater. The duration of the go-to-sleep routine can be set by the user's preferences (optionally), and the intensity, and even the color tone, can be adjusted according to preference. In the calculations, duration and illuminance are interchangeable; that is, 1 minute of 500 lux has the same effect as 5 minutes of 100 lux. Furthermore, longer wavelengths may require more time to reach the same effect as shorter wavelengths. The boost light does not have to be a single wavelength, but can be broadband, with the constraint that wavelengths >485 nm should not be used substantially. For example, turning off the blue LED in the white light spectrum of a Hue lamp, resulting in a yellowish light, is already a first approximation to such a broadband light spectrum.

[0118] In one embodiment, the present invention provides a lighting system comprising a control unit that receives control signals based on knowledge of a user's go-to-bed routine (e.g., the HUE go-to-sleep routine). The control signals can be calculated on-the-fly or can be pre-calculated to evoke light effects as described below.

[0119] In one embodiment, the invention provides a connected lighting system that receives input from (co-located) sensor(s) that can assess or infer the current "state" of a user, where the state refers to the user's lighting history, or derives this current state based on a model, e.g. from past history.

[0120] In one embodiment, the present invention provides a bulb that automatically provides a light boost first before dimming to complete darkness when the (wall) switch is turned off.

[0121] In one embodiment, the present invention provides a connected bathroom lighting system that turns on a boost light when it detects or receives a control signal that a user has started using an electric toothbrush at night (before going to bed).

[0122] The term "plurality" refers to two or more.

[0123] The terms "substantially" or "essentially" herein will be understood by those skilled in the art. The terms "substantially" or "essentially" may also include embodiments using "entirely", "completely", "all", etc. Thus, in embodiments, the adjectives substantially or essentially may be omitted. Where applicable, the terms "substantially" or "essentially" may relate to 90% or more, such as 95% or more, particularly 99% or more, more particularly 99.5% or more, e.g. 100%.

[0124] The term "comprises" also includes embodiments where the term "comprises" means "consists of".

[0125] 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" may, in one embodiment, refer to "consisting of," while in another embodiment, it may refer to "containing at least the defined species and optionally one or more other species."

[0126] Moreover, the terms first, second, third, etc. in the specification and claims 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 should be understood that the embodiments of the invention described herein are capable of operating in sequences other than as described or illustrated herein.

[0127] A device, apparatus, or system may be described herein, inter alia, as being in operation. Those skilled in the art will appreciate that the present invention is not limited to a method of operation or a device, apparatus, or system when in operation.

[0128] It should be noted that the above-described embodiments are illustrative rather than limiting of the invention, and that those skilled in the art can design many alternative embodiments without departing from the scope of the appended claims.

[0129] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0130] Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly indicates otherwise, throughout the specification and claims, the words "comprise", "comprising" and the like should be interpreted in their inclusive sense, i.e., "including, but not limited to", rather than their exclusive or exhaustive sense.

[0131] The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0132] The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device, apparatus or 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. In a still further aspect, the invention thus provides a software product which, when executed on a computer, is capable of causing (one or more embodiments of) the method as described herein.

[0133] 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.

[0134] The invention further applies to a device, an apparatus or a system comprising one or more of the features described in the present specification and / or shown in the accompanying drawings.The invention further relates to a method or process comprising one or more of the features described in the present specification and / or shown in the accompanying drawings.

[0135] The various aspects discussed in this patent may be combined to provide additional advantages. Moreover, those skilled in the art will appreciate that embodiments may be combined, and that three or more embodiments may be combined. Moreover, some of the features may form the basis for one or more divisional applications.

Claims

1. A light-generating system comprising one or more light-generating devices, each of the one or more light-generating devices configured to generate a device light, the light-generating system configured to generate a system light comprising the device light of at least one light-generating device, the light-generating system configured to provide a system light according to the following characteristics: during a first time period t1, the system light is white light having a radiant flux Φ11 in a first wavelength range and a radiant flux Φ12 in a second wavelength range, during a second time period t2, the system light is light having a radiant flux Φ21 in said first wavelength range and a radiant flux Φ22 in said second wavelength range, during a third time period t3, the system light is light having a radiant flux Φ31 in said first wavelength range and a radiant flux Φ32 in said second wavelength range, - Φ21<Φ11, Φ31<Φ11, - Φ22>Φ12, Φ32<Φ12, - t2 is selected in the range of 1 second to 30 minutes, t1>t2, the first wavelength range is from 380 nm to λ1 and the second wavelength range is from λ1 to 780 nm, λ1 being selected from the range from 485 to 550 nm; 1. A light-generating system comprising: one or more light-generating devices, the one or more light-generating devices including: (i) a first light-generating device configured to generate cool white light; and (ii) a second light-generating device configured to generate warm white light, wherein the spectral power distributions of the first device light and the second device light are different; the system light includes one or more of the cool white light and the warm white light; and during the second time period t2, a contribution of the warm white light to the system light is greater than during the first time period t1.

2. The system light has a variable luminous flux or illuminance value E ｖ and a variable luminous flux or illuminance value E of the system light during the second time period t2. ｖ The light-generating system of claim 1 , wherein: t is equal to or greater than t during the first time period t1.

3. 1.05≦R ２２，１２ ≦5, and R ２２，１２ 3. The light-generating system of claim 1 or 2, wherein: =Φ22 / Φ12.

4. When λ1 is selected from the range of 485 to 500 nm, 1.05≦R ２２，１２ ≦3.0, and when λ1 is selected from the range of 500 to 550 nm, 2.2≦R22,12≦5, and R ２２，１２ 4. The light-generating system of claim 1 , wherein:

5. R ２１，１１ *R ２２，１２ ≦5, and R ２１，１１ =Φ21 / Φ11, and R ２２，１２ 5. The light-generating system of claim 1 , wherein: =Φ22 / Φ12.

6. 6. The light generating system of claim 1, wherein λ1 is selected from the range of 490 to 530 nm and the system light during the first time period t1 has a correlated color temperature selected from the range of 2000 to 6500 K and a color point within 15 SDCM of the black body locus.

7. The system light has a variable melanopic equivalent daylight illuminance value E ｖ，ｍｅｌ Ｄ６５ a variable melanopic equivalent daylight illuminance value E of the system light during the second time period t2 ｖ，ｍｅｌ Ｄ６５ The light generation system of claim 1 , wherein x is equal to or greater than t1 during the first time period t1.

8. 8. The light generating system of any one of claims 1 to 7, wherein t2 is selected from the range of 1 to 15 minutes, t1 is at least 1 hour and t3 is selected from the range of 0 to 60 minutes, with t1 > t3.

9. 9. The light-generating system of claim 1, comprising a control system configured to control the system light in dependence on one or more of a user interface input signal, a sensor signal, and a timer.

10. The light-generating system of claim 9 , wherein the sensor is configured at least to generate the sensor signal in dependence on a parameter related to human behavior.

11. 11. The light-generating system of any one of claims 1 to 10, wherein the first light-generating device and the second light-generating device are configured in different spaces, the first light-generating device is configured to generate cool white light having a radiant flux Φ11 in the first wavelength range and a radiant flux Φ12 in the second wavelength range during the first time period t1, and the second light-generating device is configured to generate warm white light having a radiant flux Φ21 in the first wavelength range and a radiant flux Φ22 in the second wavelength range during the second time period t2.

12. 12. The light generating system according to any one of claims 1 to 11, wherein the first light generating device and / or the second light generating device are comprised in an illumination device selected from the group of a lamp, a luminaire, a projector device and an optical communication device.

Images