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 generation system and an illumination device including such a light generation system.

Background Art

[0002] Illumination devices designed for the circadian effect are known in the art. For example, US11071187 describes a circadian synchronization enhancement device including a housing, a first directional light source, a second directional light source, and a driver. During the daytime, the driver turns on the first directional light source with a high melanopic ratio to enhance the user's daytime circadian synchronization. During the nighttime, the driver turns on the second directional light source with a low melanopic ratio to enhance the user's nighttime circadian synchronization. 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 illumination of an area by an illumination system, the method including the steps of supplying general illumination by the illumination system during a predetermined general illumination period according to a predetermined time program, and supplying colored illumination during a predetermined first colored illumination period. The predetermined time program is executed for at least 6 hours. Further, a control unit configured to control the illumination system according to the predetermined time program is applied.

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

[0005] Bright light in the evening, especially light of short wavelengths, may be able to suppress the natural buildup of melatonin, a pineal hormone that is involved in preparing our bodies for sleep. The mechanism underlying the suppression of melatonin may begin with the absorption of light by melanopsin photopigment, which is present in a small subset of retinal ganglion cells (ipRGCs). These cells can signal to the brain (SCN) and cause a change in the signal that initiates 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 melanopic EDI (abbreviated as MEDI in this specification), and for example, see also: 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 thereby potentially affect melatonin production (suppression) can be quantified by melanopic equivalent daylight illuminance, also known as melanopic EDI or MEDI. The lower the MEDI at night, the better the preparation for sleep seems to be. Therefore, lighting applications that support the going-to-bed routine can lower the MEDI at night, preferably targeting 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 a low CCT value (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, there is a desire to provide improved lighting devices that can have different or better effects on the circadian rhythm.

[0006] Accordingly, one aspect of the present invention is to provide an alternative light generation system that preferably at least partially removes one or more of the above-mentioned disadvantages. The present invention may be aimed at overcoming or improving at least one of the disadvantages of the prior art or providing a useful alternative.

Means for Solving the Problems

[0007] According to a first aspect, the present invention provides a light generation system (the "system") comprising one or more light generation devices, each of the one or more light generation devices being configured to generate device light. In certain embodiments, the light generation system may be configured to generate system light that includes the device light of at least one of the one or more light generation devices. In particular, in certain embodiments, the light generation system may be configured to provide system light (in an operational mode) 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 spectral power distribution different from that of 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 period, or during the second period, or different from both. In certain embodiments, during the first time period t1, the system light may be (white) light having a radiant flux Φ11 within a first wavelength range and a radiant flux Φ12 within a second wavelength range, during the second time period t2, the system light may be light having a radiant flux Φ21 within the first wavelength range and a radiant flux Φ22 within the second wavelength range, and optionally, during the third time period t3, the system light may be light having a radiant flux Φ31 within the first wavelength range and a radiant flux Φ32 within the second wavelength range. In particular, in certain embodiments, the following conditions 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 from 380 nm to λ1, and the second wavelength range may be from λ1 to 780 nm, where λ1 may be selected from the range of 485 to 550 nm. Further, in certain embodiments, the following conditions may also apply: Φ31 < Φ11, Φ32 < Φ12, and t1 > t2.Therefore, in particular, the present invention provides a light generation system comprising one or more light generation devices, each of the one or more light generation devices being configured to generate device light, the light generation system being configured to generate system light comprising the device light of at least one light generation device, the light generation system being configured to provide the system light (in an operational mode) 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 within a first wavelength range and a radiant flux Φ12 within a second wavelength range; (B) During a second time period t2, the system light is light having a radiant flux Φ21 within the first wavelength range and a radiant flux Φ22 within the second wavelength range; (C) During a third time period t3, the system light is light having a radiant flux Φ31 within the first wavelength range and a radiant flux Φ32 within the 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] Using such a system, a kind of booster light pulse may be provided, which unexpectedly can have an advantageous effect on the circadian rhythm. Instead of reducing the intensity, a relatively strong light pulse may be provided just before going to sleep, which can have an advantageous effect. Without being bound by theory, the present invention can use the (counter-intuitive) application of relatively high-intensity light for a short time to force a part of the melanopsin pigment (the part that can actively contribute to brain signaling) into a silent state. This can effectively reduce the disturbance of the light-induced melatonin buildup and is beneficial for preparing to fall asleep. Therefore, the present invention can provide, inter alia, a go-to-sleep routine comprising a booster light pulse.

[0009] As indicated above, the light generation 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 device may in particular be configured to generate device light. In particular, the light generating device may include a light source. The light source may in particular be configured to generate source light. In certain embodiments, the device light may consist essentially of device light. In other embodiments, the device light may consist essentially of converted light source light. In yet other embodiments, the device light may include (non-converted) source light and converted light 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). Also, the term "light generating device" may refer to a plurality of light generating devices that can provide device light having essentially the same spectral power distribution. In certain embodiments, the term "light generating device" may also refer to a plurality of light generating devices that can provide device light having 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, an LED (light emissive diode). In certain embodiments, the light source includes a solid-state LED light source such as an LED or a laser diode (or "diode laser", etc.). Also, the term "light source" may 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. Further, the term "light source" may also, in certain embodiments, refer to a so-called chips-on-board (COB) light source. The term "COB" refers in particular to an LED chip in the form of a semiconductor chip directly placed on a substrate such as a PCB, which is neither encapsulated nor connected. Thus, a plurality of light-emitting semiconductor light sources may be configured on the same substrate. In certain embodiments, a COB is a multi-LED chip configured together as a single lighting module.

[0011] The light source may have a light escape surface. Referring to conventional light sources such as a light bulb or a fluorescent lamp, the light escape surface may be the outer surface of a glass or quartz envelope. In the case of an LED, the light escape surface may be, for example, the LED die, or, when a resin is applied to the LED die, the outer surface of the resin. In principle, the light escape surface may also be the end of a fiber. The term escape surface relates in particular to the part of the light source from which light actually leaves or escapes. The light source is configured to provide a light beam. This light beam escapes from the light exit surface of the light source.

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

[0013] The term "light source" may refer to semiconductor light-emitting devices such as light-emitting diodes (LEDs), resonant cavity light emitting diodes (RCLEDs), vertical cavity laser diodes (VCSELs), edge emitting lasers, etc. Also, the term "light source" may refer to organic light-emitting diodes (OLEDs) such as 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). Also, the term "light source" or "solid state light source" may refer to a superluminescent diode (SLED).

[0014] Also, the term "LED" may refer to a plurality of LEDs.

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

[0016] In one embodiment, the light source may be configured to provide primary emission, such as a blue light source such as a blue LED, a green light source such as a green LED, and a red light source such as a red LED, etc., and used by itself. It may not include a luminescence material ("phosphor"). Such an LED may be referred to as a direct color LED.

[0017] However, in other embodiments, the light source may be configured to provide primary emission, and a part of the primary emission may be converted into secondary emission. The secondary emission may be based on conversion by a luminescence material. Therefore, the secondary emission may also be referred to as luminescence material emission. In one embodiment, the luminescence material may be included in a light source such as an LED having a luminescence material layer or dome containing the luminescence material. Such an LED may be referred to as a phosphor-converted LED or a PC LED (phosphor converted LED). In other embodiments, the luminescence material may be configured at a distance ("remote") from a light source such as an LED having a luminescence material layer that is not physically in contact with the die of the LED. Thus, in certain embodiments, the light source may be a light source that emits light having a wavelength selected from at least the range of 380 to 470 nm during operation. However, other wavelengths may also be possible. This light may be partially used by the luminescence material.

[0018] In one embodiment, the light generating device may include a luminescence material. In one embodiment, the light generating device may include a PC LED. In other embodiments, the light generating device may include a direct LED (i.e., without a phosphor). In one embodiment, the light generating device may include a laser device such as a laser diode. In one embodiment, the light generating device may include a superluminescent diode. Thus, in certain embodiments, the light source may be selected from the group consisting 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 source light having, in particular, an optical axis (O), (a certain beam shape), and a certain spectral power distribution. The source light may have one or more bands having a bandwidth as known for lasers in one embodiment.

[0020] The term "light source" may refer to the light generating element itself, such as a solid light source, or, for example, a package of the light generating element, such as a solid light source, etc., an element including a luminescence material, and one or more of other optics such as lenses, collimators, etc. The light converter element ("converter element" or "converter") may include an element including a luminescence material. For example, a solid light source itself such as a blue LED is a light source. Also, a combination of a solid light source (as a light generating element) and a light converter element such as a blue LED and a light converter element optically coupled to the solid light source may also be a light source (however, it may be shown as a light generating device). Thus, a white LED is a light source (however, it may be shown as, for example, a (white) light generating device).

[0021] As used herein, the term "light source" may also refer to a light source including a solid light source such as an LED, a laser diode, a superluminescent diode, etc.

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

[0023] In certain embodiments, the term "light source" may refer to a combination of a light source, such as an LED, and an optical filter capable of changing 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 additional (optical) elements, such as an optical filter and / or a beam shaping element.

[0024] The phrases "different light sources" or "a plurality of different light sources", and similar phrases, may, in certain embodiments, refer to a plurality of solid state light sources selected from at least two different bins. Similarly, the phrases "the same light source" or "a plurality of the same light sources", and similar phrases, may, in certain embodiments, refer to a plurality of solid state light sources selected from the same bin.

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

[0026] In particular, the light generation system is configured to generate system light. The system light may include device light of at least one of the one or more light generation devices. More particularly, the system light may consist essentially of the device light of at least one light generation 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 generation device). Instead of the term "radiant flux", the terms "intensity" or "radiant power" may be applied. The term "radiant flux" may in particular have an energy unit such as watts. The term "spectral power distribution" may in particular refer to the power distribution of light as a function of wavelength (in particular in nanometers) (in particular in watts) over the human visible wavelength range (380 - 780 nm) in certain 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. The spectral flux may be expressed as power (watts) per unit frequency or wavelength. In particular, in this specification, the spectral flux is expressed as the radiant flux per unit wavelength (W / nm). Further, in this specification, the spectral flux and the radiant flux are in particular based on the spectral power of the device light over the wavelength range of 380 - 780 nm.The term "correlated color temperature" may, in particular, refer in this specification to the temperature of a Planck radiator having the 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 Planck locus and the test stimulus.

[0027] Since the system light may be controllable, in particular the spectral power distribution and the radiant flux may be controllable. For this purpose, in particular, the system may include a light generating device having a controllable spectral power distribution and / or may include two or more light generating devices. In the former (plural) embodiment, the light generating device having a controllable spectral power distribution may be controlled by a control system. In the latter (plural) embodiment, the spectral power distribution of the system light may be controlled by controlling two or more light generating devices by a control system.

[0028] Therefore, in particular, the light generating system may include a control system or may 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 where there are two or more light generating devices, 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 particularly, the radiant flux and the spectral power distribution of the system light).

[0029] The term "control" and similar terms may, in particular, at least refer to determining the behavior of an element or supervising the execution of an element. Thus, in this specification, the terms "control" and similar terms may refer to, for example, measuring, displaying, actuating, opening, shifting, changing the temperature, etc., imposing behavior on an element (determining the behavior of the element or supervising the execution of the element), etc. Additionally, the term "control" and similar terms may further include monitoring. Thus, the term "control" and similar terms may include imposing behavior on an element, or may include imposing behavior on an element and monitoring the element. The control of an element can be performed using a control system, which may be represented as a "controller". Thus, the control system and the element may be functionally coupled, at least temporarily or permanently. The element may include a control system. In certain embodiments, the control system and the element may not be physically coupled. The control can be performed via wired and / or wireless control. Also, the term "control system" may refer to a plurality of different control systems that are particularly functionally coupled, and for example, one of the control systems may be a master control system, and one or more other control systems may be slave control systems. The control system may include a user interface or may be functionally coupled to a user interface.

[0030] Also, the control system may be configured to receive and execute instructions from a remote control. In certain embodiments, the control system may be controlled via an app on a portable device, such as a smartphone or an I-phone, a tablet, etc. Thus, the device does not necessarily have to be coupled to the light generation system and may be (temporarily) functionally coupled to the light generation system.

[0031] Thus, in certain embodiments, the control system may also be configured to be controlled by an app on a remote device. In such embodiments, the control system of the light generation system may be a slave control system or may be controlled in slave mode. For example, the light generation system may be identifiable by a code, particularly a code unique to each light generation system. The control system of the light generation system may be configured to be controlled by an external control system that can access the light generation system based on knowledge of the (unique) code (input using an optical sensor, e.g., a QR code reader, or via a user interface). Also, the light generation system may 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 apparatus, or 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 denoted as "controlling mode". Similarly, in a method, an action, or step, or stage may be performed in a "mode" or "operation mode" or "mode of operation" or "operational mode". This does not preclude that a system, or apparatus, or 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 and / or after performing a mode.

[0033] However, in some embodiments, a control system adapted to provide at least a control mode may be available. If other modes are available, the selection of such a mode may depend on sensor signals or (time) schemes, and other options such as executing the mode are possible, but may be particularly executed via a user interface. The operating mode may, in some embodiments, refer to a system, or apparatus, or device that can operate only in a single operating mode (i.e., "on" without further tunability).

[0034] Accordingly, in some embodiments, the control system may control depending on one or more of an input signal of the user interface, a sensor signal (of the sensor), and a timer. The term "timer" may refer to a clock and / or a predetermined time scheme.

[0035] The light generation system may, as can be derived from the above, in some embodiments, be operable in a single operational mode, 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 this specification, in particular, an operational mode is described that provides a boost of light, which may generally mean that the light generation system provides (white) light during a first time period, and then, during a second time period, the radiant flux of light within a wavelength range below a certain wavelength is lower and the radiant flux of light within a wavelength range above a certain wavelength is higher. Thereafter, (during a third time period), the system may, in some embodiments, provide light at a lower radiant flux than during the first time period (and during the second time period), or may be turned off or switched to a sleep mode. For example, in some embodiments, for at least 6 hours after the second time period, no system light may be provided.

[0036] Accordingly, in particular, the operational mode may include 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] Therefore, in certain embodiments, the light generation system may be configured to provide system light (in the operational mode) according to the following characteristics: (a) during a first time period t1, the system light is light having a radiant flux Φ11 within a first wavelength range and a radiant flux Φ12 within 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 within the first wavelength range and a radiant flux Φ22 within the second wavelength range. Further, in particular, the following characteristics may apply: Φ21 < Φ11 and Φ22 > Φ12. In particular, in certain embodiments, the first time period may be at least about 30 minutes, etc., or at least 15 minutes. Further, in certain embodiments, t2 may be selected from the range of 1 second to 30 minutes, and more particularly may be at least about 30 seconds. When the radiant flux Φ22 within the second wavelength range during the second time period t2 is high, the second time period can be shorter, while when the radiant flux Φ22 within 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, the second wavelength range is λ1 to 780 nm, and λ1 is selected from the range of 485 to 550 nm. Accordingly, 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, system light may still be present during the third time period. Generally, the 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 about 15% lower, at least 10% lower than during the first time period, or even at least 50% lower, even further 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 1000 K lower, at least 500 K lower. As also shown below, in some embodiments, after the second time period, the system light may be essentially turned off (such that there is no third time period). The lower radiant flux and / or lower CCT during the third time period can reduce the potential adverse effects on the circadian rhythm.

[0040] In particular, t1 + t2 + t3 ≦ 24 hours. For example, t1 + t2 + t3 ≦ 16 hours. Note that in certain embodiments, t1 + t2 + t3 ≧ 2 hours. Further, in certain embodiments, t1 ≧ t2 + t3 may be applicable.

[0041] Thus, in certain embodiments, the light generation system may be configured to provide system light (in an operational mode) according to the following characteristics: (a) during a first time period t1, the system light is light having a radiant flux Φ11 within a first wavelength range and a radiant flux Φ12 within a second wavelength range, particularly white light, (b) during a second time period t2, the system light is light having a radiant flux Φ21 within the first wavelength range and a radiant flux Φ22 within the second wavelength range, and (c) during a third time period t3, the system light is light having a radiant flux Φ31 within the first wavelength range and a radiant flux Φ32 within the second wavelength range. Further, particularly the following characteristics may also apply: Φ21 < Φ11 and Φ31 < Φ11. Still further, particularly the following characteristics may also apply: Φ22 > Φ12, and Φ32 < Φ12. In particular, as also shown above, t2 may be selected from the range of 1 second to 30 minutes, and particularly t1 > t2 may be the case. Further, as described above, 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.

[0042] The term "white light" and similar terms in this specification are known to those skilled in the art. This may relate in particular to light having a correlated color temperature (CCT) between 2000K and 20000K, in particular between about 1800K and 20000K such as between 2700 and 20000K, and in particular for general illumination, within a range of correlated color temperature (CCT) within the range of about 2000 - 7000K such as within the range of 2700K and 6500K. In certain embodiments, for example for backlighting purposes or for other purposes, the correlated color temperature (CCT) may in particular be within the range of about 7000K and 20000K. Even further, in certain embodiments, the correlated color temperature (CCT) is in particular within about 15 standard deviations of color matching (SDCM) from the BBL (black body locus), in particular within about 10 SDCM from the BBL, and even more particularly within about 5 SDCM from the BBL. As will be further elucidated below, in this specification, the CCT may in particular be selected from the range of 2000 - 6500K, for example from the range of 2000 - 4000K. Further, it should be noted that in certain embodiments, the CCT may vary over time, such as a higher CCT during a first time period and an (optional) lower CCT during a third time period. In certain 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 described above, the system light during the first time period may be white light. However, in other particular embodiments, the system light during the first time period is visible light but not white light. In particular, in certain embodiments, Φ11 / Φ12 ≧ 0.001, and more particularly, in certain embodiments, Φ11 / Φ12 ≧ 0.005. In certain embodiments, 0.001 ≦ Φ11 / Φ12 < 1 such as 0.005 ≦ Φ11 / Φ12 ≦ 0.5. If Φ11 is zero, 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 within the range of about 380 - 780 nm. In this specification, UV may refer to wavelengths selected from the range of 190 - 380 nm, such as, in particular, 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 in the case of lighting applications, the terms "light" and "radiation" refer to (at least) visible light. The terms "violet light" or "violet emission", and similar terms, may relate in particular to light having wavelengths within the range of about 380 - 440 nm. In certain embodiments, the violet light may have a centroid wavelength within the range of 380 - 440 nm. The terms "blue light" or "blue emission", and similar terms, may relate in particular to light having wavelengths within the range of about 440 - 490 nm (including some violet and cyan hues). In certain embodiments, the blue light may have a centroid wavelength within the range of 440 - 490 nm. The terms "green light" or "green emission", and similar terms, may relate in particular to light having wavelengths within the range of about 490 - 560 nm. In certain embodiments, the green light may have a centroid wavelength within the range of 490 - 560 nm. The terms "yellow light" or "yellow emission", and similar terms, may relate in particular to light having wavelengths within the range of about 560 - 590 nm. In certain embodiments, the yellow light may have a centroid wavelength within the range of 560 - 590 nm.The terms "orange light" or "orange emission", and similar terms, may relate in particular to light having wavelengths in the range of about 590 - 620 nm. In certain embodiments, the orange light may have a centroid wavelength within the range of 590 - 620 nm. The terms "red light" or "red emission", and similar terms, may relate in particular to light having wavelengths in the range of about 620 - 750 nm. In certain embodiments, the red light may have a centroid wavelength within the range of 620 - 750 nm. The terms "cyan light" or "cyan emission", and similar terms, relate in particular to light having wavelengths in the range of about 490 - 520 nm. In certain embodiments, the cyan light may have a centroid wavelength within the range of 490 - 520 nm. The terms "amber light" or "amber emission", and similar terms, may relate in particular to light having wavelengths within a range such as about 590 - 600 nm, about 585 - 605 nm. In certain embodiments, the amber light may have a centroid wavelength within 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 at which half of the optical energy is at shorter wavelengths and half of the optical energy is at longer wavelengths, and the value is stated in nanometers (nm). This is the wavelength that bisects the integral of the spectral power distribution, as represented 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 integral of the product of wavelength and intensity over the emission band, normalized by the integrated intensity). The centroid wavelength may be determined, for example, by operating conditions.

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

[0047] In certain embodiments, in order to obtain an effect, R 22,12 ≧ 1.05, and it would seem desirable that R 22,12 = Φ22 / Φ12. Further, in order to obtain a (strengthened) effect, it may be beneficial if at the same time R 21,11 ≦ 0.9, and R 21,11 = Φ21 / Φ11. Therefore, in certain embodiments, 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 an alternative embodiment, 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 decrease more than one or more other portions, and indeed, one or more portions of the spectral power distribution below λ1 may increase while one or more other portions decrease more (such that overall R 21,11 < 1).

[0049] The radiant flux increase above λ1 (during the second time period) may be evenly distributed across the spectral power distribution above λ1. In an alternative embodiment, 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, or even, while one or more other portions increase, one or more portions of the spectral power distribution above λ1 may decrease (such that R 22,12 > 1 overall). 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 such that R 21,11 <1, and more particularly R 21,11 ≦ 0.9, and R 22,12 > 1, and more particularly R 22,12 ≧ 1.05.

[0050] For a wavelength λ1 selected from the range of about 485 - 550 nm and a CCT of the system light selected from the range of about 2000 - 6500 K, particularly from the range of 2000 - 4000 K, R 22,12 may, in one embodiment, be up to about 5. Larger values may be possible, particularly at higher CCTs and / or higher values of the λ1 wavelength (see also below). Thus, values of the λ1 wavelength greater than 550 nm may not be very desirable. Further, since the ratio of R 22,12 can be relatively high, a CCT not higher than about 6500 K, such as not higher than 5000 K, may be desirable.

[0051] In one embodiment, particularly at higher wavelengths of λ1, R 22,12 may take on values greater than 5, for example greater than 10. This may be the case particularly when R 21,11 is selected to be high (yet still below 1). For a relatively high R 22,12Since a sudden large increase in intensity may not necessarily be preferred by the user, it may not be very desirable. Thus, in certain embodiments in particular, λ1 and R 21,11 are selected such that 1.05 ≦ R 22,12 ≦ 7, and more particularly 1.05 ≦ R 22,12 ≦ 5. In particular, in certain embodiments, 1.05 ≦ R 22,12 ≦ 4. Thus, in particular, R 22,12 ≦ 7, and more particularly R 22,12 ≦ 5, for example R 22,12 ≦ 4.

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

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

[0054] In one embodiment, the increase in the (second) radiant flux during the second time period within the wavelength range above λ1 may be relatively smaller than the decrease in the first radiant flux within the wavelength range below λ1. R 22,12 With a relatively small change in R 22,12 , it may be possible to already obtain the desired effect, so it may be desirable to use a smaller value of R

[0055] In certain embodiments, R 21,11 *R 22,12 ≦5. For example, in one embodiment, R 21,11 *R 22,12 ≦4, for example, in a further particular embodiment, R 21,11 *R 22,12 ≦2.

[0056] For values of λ1 less than about 485 nm, the effect may be relatively small, and for values of λ1 greater than about 550 nm, the effect may decrease, and / or may only be obtained when using a relatively large increase in the radiant flux (R 22,12 ), and / or the effect may only be obtained at a lower CCT 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 is, the more desirable it may be to increase R 22,12 . This may lead to non - practical situations (i.e., not achievable with indoor light sources). Furthermore, the higher the split wavelength λ1, the smaller the reduction in % of the active melanopsin pigment may be. From the perspective of efficiency, the split wavelength may be selected to be as low as possible, particularly not greater than at least 530 nm.

[0058] In one embodiment, the selection of the splitting wavelength λ1 can be made based on considerations regarding, for example, the upper emitting wavelength of the blue primary light source. When using this splitting wavelength, the intensity change of wavelengths <λ1 may be performed 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, particularly 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 be different from the spectral power distribution of the system light during the second time period. In certain embodiments, the color or color point of the first type of light and the second type of light may be different 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', and even more particularly differ 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'. Here, u' and v' are the color coordinates of the light in the CIE1976 UCS (uniform chromaticity scale) diagram. Spectral power distributions of different light sources with a centroid wavelength difference of at least 10 nm, for example at least 20 nm, or even at least 30 nm different may be considered different spectral power distributions, for example, different colors. Generally, the difference in centroid wavelength will not be greater than about 400 nm, such as 350 nm or less.

[0061] In one embodiment, the light generation system may include at least two (i.e., two or more) light generation devices configured to generate device light having different spectral power distributions. In this way, by controlling at least two light generation devices, the spectral power distribution and the radiation beam(s) of the system light may be controlled. Therefore, in one embodiment, one or more light generation devices include (i) a first light generation device configured to generate a first device light, and (ii) a second light generation device configured to generate a second device light, wherein 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 one embodiment, one of the two or more light generation devices may be configured to generate white light having a relatively low content of one or more of green light, yellowish light, orange light, and red light, and another one of the two or more light generation 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 one embodiment, one of the two or more light generation devices may be configured to generate white light, while another one of the two or more light generation 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 one embodiment, one of the two or more light generation devices may be configured to generate colored light having one or more wavelengths within the blue wavelength range and / or one or more wavelengths within the green wavelength range, and another one of the two or more light generation 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 cool white light, the second device light may be 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 generation system can always provide system light useful for pre-sleep human activities that require acceptable white light conditions or pre-sleep human activities that require acceptable white light conditions without interfering with human melatonin production in the evening and before sleep. Such human activities include, for example, winding down, reading in bed, pre-sleep toothbrushing, walking towards the bedroom, loading a night-time dishwasher, etc.

[0066] (Alternative) In certain embodiments, the first device light may be cool white light, the second device light may be colored light having one or more wavelengths within at least one of the yellow wavelength range, the orange wavelength range, and the red wavelength range, 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.

[0067] Of course, the above examples may refer to two (or more) sets of light generating devices. The light generating devices within a set may be configured to generate device light having essentially the same spectral power distribution, and 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 of λ1 < λ2 ≤ 650 nm, such as selected from the range of λ1 < λ2 ≤ 780 nm.

[0069] In particular, in certain embodiments, 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 certain embodiments, 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, the centroid wavelength of the system light during the first time period may be smaller than that during the second time period.

[0071] The ratio of Φ31 / Φ11 may be defined as R 31,11 In certain embodiments, t3 is not equal to 0 minutes, and R 31,11 < 1. In particular, in certain embodiments, R 31,11 ≤ 0.5. The ratio of Φ32 / Φ12 may be defined as R 32,12 In certain embodiments where t3 is not equal to 0 minutes, R 32,12 < 1. In particular, in certain embodiments, R 32,12 ≤ 0.5.

[0072] In certain embodiments (where t3 is not equal to 0 minutes), the spectral power distributions of the system light during the first time period and the third time period are the same (however, the radiant fluxes are different). In alternative embodiments (where t3 is not equal to 0 minutes), the spectral power distributions of the system light during the second time period and the third time period are the same (however, the radiant fluxes are 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 may be configured to generate a system light during the second time period having an illuminance, defined as the luminous flux per unit area (1 m 2 ) incident on a surface of at least 100 lux, such as at least 250 lux, such as at least 500 lux.

[0075] In an embodiment (t3 not equal to 0 minutes), the system may be configured to generate a system light during the third time period having an illuminance, defined as the luminous flux per unit area (m 2 ) incident on a surface of up to 100 lux, such as up to 50 lux, such as in particular up to 10 lux.

[0076] In an embodiment, 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 the variable illuminance value E v of the system light during the second time period t2 is equal to or greater than the illuminance value E v of the system light during the first time period t1. Of course, the same relationship applies to the luminous flux or luminous power of the system light (expressed in "lumens"). This is quite counter-intuitive, since the general teaching is to turn down the light intensity before sleep, not turn it up.

[0077] In one embodiment, the variable illuminance value E v of the system light during the first time period t1 is equal to or greater than the illuminance value E v of the system light during the first time period t1.v and the variable melanopic equivalent daylight illuminance value E v,mel D65 Both are greater during the second time period t2 than during the first time period t1. Therefore, in certain embodiments, the system light has a variable illuminance value E v and the variable melanopic equivalent daylight illuminance value E v,mel D65 and has, for the system light, (i) a variable illuminance value E v and (ii) a variable melanopic equivalent daylight illuminance value E v,mel D65 wherein one or more of them are greater during the second time period t2 than during the first time period t1. Therefore, in certain embodiments, 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 that during the first time period t1. Further, in certain embodiments, the variable illuminance value E of the system light v and the variable melanopic equivalent daylight illuminance value E v,mel D65 both are less 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 referred to as a boost pulse, may be provided for a relatively short period. For example, such a boost pulse may be provided immediately before going to sleep and may last, for example, up to about 30 minutes. The time may depend on the radiant flux. Generally, the greater the radiant flux of the system light during the second period, the shorter the second period can be. Thus, the smaller the radiant flux of the system light during the second period, the longer the second period may be selected. In certain embodiments, t2 may be selected from a range of at least 30 seconds, such as 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 essentially be any time period, but in particular, it may not be longer than about 20 hours, such as not longer than about 16 hours. In certain embodiments, t1 may be at least about 1.5 hours, such as at least 1 hour. For example, t1 may be selected from the range of 1 to 6 hours, such as 30 minutes to 8 hours. For example, t1 may be a period selected within the time frame of 17:00 to 24:00 h. In particular, the first time period may be a period during dusk.

[0080] In certain embodiments, the boost pulse may be provided during the period before entering sleep where system light is provided, such that the boost pulse divides this period into two (or effectively three) periods where the time preceding the boost pulse is the first period and the period following the boost pulse is the third period. The optical properties such as the spectral power distribution and radiant flux during the first time period and the third time period may be the same or different. In particular, as also shown above, the radiant flux may be lower for the system light during the third period compared to the first period, and / or the CCT may be lower. Thus, the third period may in particular be the period immediately before entering sleep.

[0081] In certain embodiments, t3 may be at most 2 hours. A period that is too long may have a detrimental effect on the effect of the boost pulse. Thus, in certain embodiments, t3 may be selected from the range of 0 to 45 minutes, such as 0 to 60 minutes, for example, in certain embodiments, at least about 10 minutes. In particular, in certain embodiments, t1 > t3. Further, in other embodiments, t3 is 0 minutes. In alternative embodiments, in certain embodiments, t3 > t2, such as t3 > 0 minutes. However, in further alternative embodiments, t2 > t3. In particular, however, as shown above, t3 ≤ 60 minutes, more particularly t3 ≤ 30 minutes, for example t3 ≤ 15 minutes, for example selected from the range of 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 can be.

[0082] As described above, the system may further include a control system configured to control the system light depending on one or more of an input signal of the user interface, a sensor signal (of the sensor), and a timer. In certain embodiments, the sensor may be at least configured to generate a sensor signal depending on parameters regarding 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 human behavior of the person using the system based on the sensor signal. For example, routines such as turning on the dishwasher, turning off a particular light, dimming the light, using the stairs, using the bathroom, brushing teeth, etc., may lead to recognizable patterns when combined with time. In such embodiments, the system may determine the moment when a person desires to go to sleep and provide a boost pulse at the calculated time. Thus, in certain embodiments, the system may be a self-learning system.

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

[0084] The system may further include a third light generation device configured in a space different from the first space in which the first light generation device is configured and optionally different from the second space in which the second light generation device is configured. In one embodiment, the space in which the third light generation device may be configured is selected from a bathroom, a toilet, and a bedroom, and in particular, the third light generation device may be configured in a bedroom. In certain embodiments, three light generation devices configured to be spatially different may be configured to generate system light in different spaces during the three mentioned time periods, respectively. In yet other specific embodiments, two light generation devices configured to be spatially different may be configured to generate system light in different spaces during the first time period and the second time period, respectively.

[0085] The light generation system may be part of, for example, a household lighting system, an accent lighting system, a spot lighting system, an optical fiber application system, a projection system, a self-luminous display system, a pixelated display system, a segmented display system, a decorative lighting system, etc., or may be applied thereto.

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

[0087] In a further aspect, the invention also provides a method of generating system light (i.e., light provided by a light generation system, particularly a light generation system as described herein), the method comprising: (a) generating system light having a radiant flux Φ11 within a first wavelength range and a radiant flux Φ12 within a second wavelength range, particularly white system light, during a first time period t1; (b) generating system light having a radiant flux Φ21 within the first wavelength range and a radiant flux Φ22 within the second wavelength range during a second time period t2; and (c) optionally generating system light having a radiant flux Φ31 within the first wavelength range and a radiant flux Φ32 within the second wavelength range during a third time period t3, wherein 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 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.

[0088] As indicated above, the third step of generating system light during the third time period t3 is optional. When available, t3 > 0 minutes (particularly at least 1 second, etc.), and when this step 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 embodiments where t1 and t2 are not equal to 0 minutes and t3 may be 0 minutes or greater than 0 minutes (however, particularly 2 hours or less, more particularly 1 hour or less (see also above)). When t3 = 0 minutes, of course, the radiant flux Φ31 within the first wavelength range and the radiant flux Φ32 within the second wavelength range are also zero. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Here, embodiments of the invention will be described by way of example only with reference to the accompanying schematic drawings in which corresponding reference numerals indicate corresponding parts. The schematic drawings are not necessarily to scale.

Figure 1a

Figure 1b

Figure 1c

Figure 2

Figure 3a

Figure 3b

Figure 3c

Figure 4a

Figure 4b

DETAILED DESCRIPTION OF THE INVENTION

[0090] Current lighting applications ignore the finding reported 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) that melanopsin pigments have been shown to be tri-stable. When stimulated by light, the process of photo-conversion (isomerization) can distribute the melanopsin pigment into three states (two silent and one signaling). This is schematically shown in FIG. 1a with the labels 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 photo pigment changes, the photoconversion processes between the R and M states, and between the M and E states reach a new equilibrium. This can take time, depending on both the spectrum and intensity of the light. The relative spectral distribution determines the pigment fraction at equilibrium, and the absolute intensity determines the rate of the process. At high light intensities, this can be a few seconds, while low light intensities may require several hours to reach this equilibrium point. Emanuel et al. demonstrated many white light sources in terms of their ability to change the pigment fraction. The broadband white light sources selected by Emanuel et al. were found to maintain a more or less stable pigment fraction. Furthermore, stimulation with monochromatic light appears to be able to change the fraction considerably.

[0092] The present invention can, in particular, take into account the fraction of "signaling" melanopsin pigments, thereby providing a novel and more optimized way of controlling the sensitivity of the melanopsin system by light, as opposed to darkness, which may seem counterintuitive. Specifically, the application of short-duration, intense light to rapidly drive a portion of the melanopsin signaling state into silence is described herein. This approach may seem counterintuitive because more light (higher lux levels), rather than less light, is used (temporarily) to reduce melanopic activation. Short-duration, intense light can be extended to longer-duration, less intense light if it is more convenient for the end user. In this case, the duration of the shift of the bistable melanopsin to the silent state will be longer, but still silent compared to normal white and dimming situations commonly used.

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

[0094] The magnitude of the decrease in the pigment fraction, and the rate at which it occurs, depend entirely on the spectrum and intensity of the light. Longer wavelengths may (substantially) require more time compared to shorter wavelengths. However, shorter wavelengths should not be used for the purpose of enhancing / maintaining a low pigment fraction in the M state (see also Figure 1a). Thus, how much the fraction can be decreased may depend on the choice of wavelengths used and the time available to the user.

[0095] Figure 1c shows an example where a large decrease (from 0.48 to about 0.3) can be obtained using light of wavelength 525 nm. This example also shows that the decrease is obtained more rapidly when the lux level is increased from 100 lux to 500 lux, which is totally counter-intuitive. Approximately, when the illuminance increases by a factor of 10, the process becomes 10 times faster. The simulation shows that the pigment fraction can be significantly decreased from 0.48 to 0.3 according to the present invention, and this itself would be a very effective solution for people to prepare to fall asleep, assuming that the user turns off all bedroom lighting within a reasonable short time after the light intervention.

[0096] Referring to FIGS. 2-3, several aspects and embodiments are (schematically) shown.

[0097] FIG. 2 schematically shows one embodiment of the light generation system 1000. However, many other embodiments within the scope of the claims are contemplated. The light generation system 1000 includes one or more light generation devices 100. Each of the one or more light generation devices 100 is configured to generate device light 101. The light generation system 1000 may be configured to generate system light 1001 that includes the device light 101 of at least one light generation device 100. The light generation system 1000 may be configured to provide the system light 1001 (in an operating mode) according to one or more, particularly all, of the following characteristics: (a) During a first time period t1, the system light 1001 may be (white) light having a radiation flux Φ11 within a first wavelength range and a radiation flux Φ12 within a second wavelength range. (b) During a second time period t2, the system light 1001 may be light having a radiation flux Φ21 within the first wavelength range and a radiation flux Φ22 within the second wavelength range. (c) During a third time period t3, the system light 1001 may be light having a radiation flux Φ31 within the first wavelength range and a radiation flux Φ32 within the 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 certain embodiments, R 21,11 = Φ21 / Φ11, R 22,12 = Φ22 / Φ12, R 21,11 ≦ 0.9, and R 22,12 ≧ 1.05. In certain embodiments, 1.05 ≦ R 22,12 ≦ 5. In particular, in certain embodiments, when λ1 may be selected from the range of 485 to 500 nm, 1.05 ≦ R 22,12is ≦3.0, and when λ1 may be selected from the range of 500 to 550 nm, 2.2 ≦ R 22,12 ≦5. In a particular embodiment, R 21,11 *R 22,12 ≦5. In one embodiment, λ1 may be selected from the range of 490 to 530 nm. In one embodiment, 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 from the range of 2000 to 4000 K.

[0099] FIG. 2 schematically shows an embodiment of a system 1000 in which one or more light generation devices 100 include (i) a first light generation device 110 configured to generate a first device light 111 and (ii) a second light generation 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. The reference numeral 301 indicates a user interface that may optionally be included in the system 1000.

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

[0101] Furthermore, in one embodiment, 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 one embodiment, the second device light 121 may be colored light having a centroid wavelength λ2 selected from the range of λ1 < λ2 ≦ 780 nm.

[0103] In certain embodiments, 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 of λ1 < λ2 ≤ 650 nm.

[0104] In particular, in certain embodiments, the second device light 121 may have a centroid wavelength λ2 selected from the range of λ1 < λ2 ≤ 550 nm.

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

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

[0107] Also, as schematically shown in FIG. 2, the light generation system 1000 may further include a control system 300 configured to control the system light 1001 depending on one or more of an input signal of the user interface, a sensor signal (of the sensor), and a timer. In certain embodiments, the sensor 310 may be at least configured to generate a sensor signal depending on a parameter related to human behavior.

[0108] Figure 3a schematically shows the spectral power distribution of the system light 1001, where λ1 is approximately 500 nm, the dashed curve is the spectral power distribution during the first time period, and the solid line distribution is the spectral power distribution during the second time period. Here, 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 an alternative embodiment, the reduction in the radiation flux below λ1 (during the second time period) need 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 reduced more than one or more other portions, or even (such that R 21,11 > 1) while one or more portions of the spectral power distribution below λ1 increase, one or more other portions may be reduced more. Similarly, in an alternative embodiment, the increase in the radiation flux above λ1 (during the second time period) need 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, or even (such that R 22,12 > 1) while one or more portions of the spectral power distribution above λ1 decrease, one or more other portions may increase more. As described above, in particular, R 21,11 = Φ21 / Φ11, R 22,12 = Φ22 / Φ12, R 21,11 ≤ 0.9, and R 22,12 ≥ 1.05.

[0110] Figure 3b shows some possible radiation fluxes over time as an example. The booster light pulse Φ22 is clearly visible at the second time period t2.

[0111] (For different intensity reduction factors with respect to the (split wavelength) wavelength, the multiplication factor required at a minimum for the split < wavelength to create optical boosting was determined.)

[0112] The following table and Figure 3c show an exemplary curve for 2700K, λ1 = 500nm. In the following table, some further results of the multiplication factor are provided. Here, λ1 indicates the wavelength at which the spectral power distribution is divided into a part below (<λ1) and a part above (>λ1). Values at different CCTs are provided. The multiplication factor is determined for a 5 - minute booster light pulse duration.) TIFF0007679562000001.tif58168TIFF0007679562000002.tif120163TIFF0007679562000003.tif128168TIFF0007679562000004.tif208165TIFF0007679562000005.tif137169

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

[0114] From the above table, at higher CCTs and larger split wavelengths, it seems that even the minimum multiplication factor or ratio R22,12 can be greater than 5 (for example, referring to a split wavelength of 550nm where the minimum ratio R22,12 for 1 entry is 15.6). If it is desired to stay below a value of 5, the multiplication factor in the lower wavelength range (<λ1) may be adapted, and / or the split wavelength may be adapted (i.e., in this example of 550nm, it may be lowered below 550nm). Note that 550nm is relatively large in any case. In particular, λ1 may be selected from the range of 490 - 530nm.)

[0115] Figure 4a schematically shows an embodiment of a lighting fixture 2 including the above-described light generation system 1000. Reference numeral 301 indicates a user interface that may be functionally coupled to a control system 300 included in or functionally coupled to the light generation system 1000. Further, Figure 4a schematically shows an embodiment of a lamp 1 including the light generation system 1000. Reference numeral 3 indicates a projector device or projector system that may be used to project an image on a wall or the like, and the projector device or projector system may also include the light generation system 1000. Accordingly, Figure 4a schematically shows an embodiment of a lighting device 1200 selected from the group of a lamp 1, a lighting fixture 2, a projector device 3, a disinfection device, a photochemical reactor, and a light wireless communication device, including the light generation system 1000 described herein. In certain embodiments, such a lighting device may be a lamp 1, a lighting fixture 2, a projector device 3, a disinfection device, or a light wireless communication device. The lighting device light escaping from the lighting device 1200 is indicated by reference numeral 1201. The lighting device light 1201 may consist essentially of the system light 1001, and thus, in certain embodiments, may be the system light 1001.

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

[0117] In particular, the present invention provides an illumination system to which at least one light setting providing a "high intensity" setting having a dominant wavelength of, for example, 485 nm or more is applied before going to sleep. The duration of the go-to-sleep routine can be set according to the user's preference (optional), and the intensity, and even the color tone, can be adjusted according to the preference. In the calculation, the duration and the illuminance are interchangeable. That is, one minute at 500 lux has the same effect as five minutes at 100 lux. Further, a longer wavelength may require more time to achieve the same effect as a shorter wavelength. The boost light does not have to be a single wavelength and can be broadband with the constraint that wavelengths greater than 485 nm should not be substantially used. For example, turning off the blue LED in the white light spectrum of the Hue lamp, which results in yellowish light, is already a first approximation to such a broadband light spectrum.

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

[0119] In one embodiment, the present invention provides a connected lighting system that receives input from (co-located) sensors that can evaluate or infer the user's current "state", where the state refers to the user's lighting history or, for example, derives this current state based on a model 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 boost light when it detects or receives a control signal that the user has started or is about to start 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 terms such as "entirely", "completely", "all", etc. Thus, in an embodiment, the adjectives substantially or essentially may sometimes be deleted. Where applicable, the term "substantially" or the term "essentially" may relate to 90% or more, for example 95% or more, particularly 99% or more, even more particularly 99.5% or more, for example 100%.

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

[0125] The term "and / or" relates in particular to one or more of the items mentioned before and / or after "and / or". For example, the phrase "item 1 and / or item 2", and similar phrases, can relate to one or more of item 1 and item 2. The term "comprising", in one embodiment, may refer to "consisting of", but in another embodiment, may also refer to "containing at least the defined species and optionally one or more other species".

[0126] Furthermore, terms such as first, second, third, etc. in the specification and claims are used to distinguish similar elements and are not necessarily used to describe a sequential or chronological order. Such terms are interchangeable under appropriate circumstances, and it should be understood that the embodiments of the invention described herein are operable in an order other than those described or illustrated herein.

[0127] A device, apparatus, or system may, among other things, be described herein with respect to its operation. As will be apparent to those skilled in the art, the present invention is not limited to a method of operation or a device, apparatus, or system during operation.

[0128] Note that the above-described embodiments are illustrative rather than limiting of the invention, and 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] The use of the verb “to comprise” and its inflected forms does not exclude the presence of elements or steps other than those recited in a claim. Unless the context clearly dictates otherwise, throughout the specification and claims, the terms “comprise,” “comprising,” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, in the sense of “including, but not limited to.”

[0131] The articles “a” or “an” preceding an element do not exclude the presence of a plurality of such elements.

[0132] The present invention may be implemented by means of hardware that includes several distinct elements and, preferably, by a computer suitably programmed. In device claims, apparatus claims, or system claims listing several means, several of these means may be embodied by 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 advantageously used. In a further aspect, the present invention provides a software product that, when executed on a computer, is capable of causing a method (one or more embodiments of which are described herein).

[0133] The present invention also provides a control system that can control a device, apparatus, or system, or execute a method or process described herein. Additionally, the present invention also provides a computer program product that, when executed on a computer that is functionally 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 present invention further applies to a device, apparatus, or system that includes one or more of the features described in the text of the specification and / or shown in the accompanying drawings. The present invention further relates to a method or process that includes one or more of the features described in the text of the specification and / or shown in the accompanying drawings.

[0135] The various aspects discussed in this patent can also be combined to provide further advantages. Furthermore, those skilled in the art will understand that embodiments can be combined, and that it is also possible to combine three or more embodiments. Furthermore, 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 2. The light-producing system of claim 1 , wherein:

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 2. The light-producing system of claim 1 , wherein:

5. R ２１，１１ *R ２２，１２ ≦5, and R ２１，１１ =Φ21 / Φ11, and R ２２，１２ 2. The light-producing system of claim 1 , wherein:

6. The light generating system of claim 1, wherein 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 blackbody 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-generating system of claim 1 , wherein: t is equal to or greater than t during the first time period t1.

8. 2. The light generating system of claim 1, 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. 10. 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. 2. The light-generating system of claim 1, 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. 2. The light generating system of claim 1, 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.

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