Circadian lighting device.

Abstract

The circadian lighting device (20) includes a tunable light source (200) to provide a plurality of predetermined lighting scenarios. The source (200) comprises a first unit (212) of white light whose light spectrum extends mainly in a wavelength range between 400 nm and 800 nm and a second unit (214) of blue light whose light spectrum forms a narrow peak whose apex is between 400 and 500 nm.The device (20) includes a control module (220) for the light power of the two units (210; 212, 214) independently of each other in order to obtain a spectral mixing ratio of the two units, variable as a function of time, by varying the light power of each of the units (210; 212, 214) between maximum and minimum values, the light power emitted by the second unit (214) always being less than or equal to 35% of the total power emitted by the light source (200). Figure 1.

Description

Title of the invention: Circadian lighting device.

[0001] The present invention relates to a lighting device with a circadian lighting function, in particular for synchronizing a biological clock of a human organism.

[0002] The biological or circadian clock allows the human organism to regulate certain functions of the human body over a period of one day, more precisely over a period which can vary between 23:30 and 24:30 depending on the individual.

[0003] Located in the brain, this biological clock is composed of several thousand neurons whose pulsatile activity controls in particular the wake / sleep cycle, body temperature, heart rate, hormone secretion, cell division, DNA repair, etc.

[0004] In order to constantly resynchronize itself throughout the day, this clock takes into account signals from the external environment, and in particular light. Inappropriate exposure to light, for example produced by artificial lighting, can create a phase shift in the biological clock with consequences on cognitive functions, sleep, alertness, memory, and cardiovascular functions of the human body.

[0005] This biological clock is likely to be disrupted: prolonged exposure to screens, jet lag, night work, poor lifestyle, etc. Undesirable and unpleasant effects on the human body are then felt for several days: disruption of the sleep / wake cycle, difficulty concentrating, irritability, seasonal depression.

[0006] For example, crossing multiple time zones on long-haul flights affects the human body's internal clock and desynchronizes the sleep / wake cycle with the arrival location. This phenomenon is known as jet lag.

[0007] In particular, to remedy jet lag syndrome, one solution is the use of light therapy devices, before the flight or after the flight. These light therapy devices are, for example, known for the treatment of seasonal depression.

[0008] Existing light therapy devices can be grouped into two functional categories: light therapy and variable white balance lighting, better known by the Anglo-Saxon expression “tunable white”.

[0009] Light therapy allows for the punctual production of intense lighting with a spectrum close to that of the sun at a specific time of day. The treatment generally lasts less than an hour and has a fixed, predefined spectrum. the manufacturer.

[0010] With variable white balance lighting, the luminaire is configured to generate white light whose light spectrum varies dynamically typically in color temperature ranges from 2700K to 6500K and whose light intensity is also adjustable.

[0011] The main objective of these devices is to stimulate a natural light cycle in an indoor environment and reproduce, either artificially sunlight over a period of one day or in a more punctual and intense manner over a short period, a white light close to sunlight at the Zenith.

[0012] In order to remedy jet lag syndrome, these devices offer a global approach which consists of artificially recreating sunlight and subjecting the passenger to an alternating phase of exposure to light and darkness before departure or upon arrival. But this solution gives poor results and is restrictive for the passenger.

[0013] The invention aims in particular to propose lighting devices with an effective circadian lighting function for synchronizing an individual's biological clock. Description of the invention

[0014] For this purpose, the subject of the invention is a circadian lighting device comprising a tunable light source for providing a plurality of predetermined lighting scenarios, characterized in that the source comprises a first white light unit whose light spectrum extends mainly in a wavelength range between 400 nm and 800 nm and a second blue light unit whose light spectrum forms a narrow peak whose summit is between 400 and 500 nm and in that the device comprises a module for controlling the light power of the two units independently of each other in order to obtain a spectral mixing ratio of the two units, variable as a function of time, by varying the light power of each of the units between maximum and minimum values, the light power emitted by the second unit always being less than or equal to 35% of the total power emitted by the light source.

[0015] The effectiveness of the device of the invention is based mainly on the activation by the second unit of the melanopsin ganglion cells located in the retina of the eye. These photoreceptor cells are essential for the transmission of light information to numerous non-visual centers of the brain. The activation or not of this second unit makes it possible to artificially accentuate the stimulation or not of the non-visual pathways and thus makes it possible to influence in particular the secretion of hormones of the human organism subjected to this lighting. The device of the invention thus offers a dynamic biological synchronization allowing a personalization of the treatment according to the needs of an individual.

[0016] A device according to the invention may comprise one or more of the following characteristics.

[0017] In a preferred embodiment of the invention, in a stimulation scenario, the control module is configured to gradually vary the light power of the second unit from zero power to a maximum power corresponding to at most 35% of the total power of the light source.

[0018] In a preferred embodiment of the invention, the first white light unit comprises a first sub-channel of warm white light with a color temperature around 6500 Kelvin and a second sub-channel of cool white light with a color temperature around 2700 Kelvin.

[0019] In a preferred embodiment of the invention, the control module is configured to vary the light power of the second unit between a zero value and a maximum value according to a pulse train profile, for example with a repetition period of between 12 minutes and 18 minutes.

[0020] In a preferred embodiment of the invention, the source comprises a third unit whose light spectrum is relatively enriched with wavelengths greater than 560nm and relatively devoid of wavelengths less than 560nm.

[0021] In a preferred embodiment of the invention, in a recovery scenario, the control module is configured to vary the light power of the first unit to a substantially zero power and to maintain only the light power of the third unit at a non-zero value.

[0022] In a preferred embodiment of the invention, the duration of a treatment scenario is between 80 minutes and 100 minutes, preferably 90 minutes.

[0023] In a preferred embodiment of the invention, the device comprising a user interface, the control module comprises means for generating the control signals for the lighting units as a function of a data frame generated following the selection by an operator of a scenario from a plurality of predetermined scenarios.

[0024] In a preferred embodiment of the invention, the device comprises a recommendation module configured to generate a recommendation level for each lighting scenario and a recommended time slot for applying each scenario.

[0025] In a preferred embodiment of the invention, said recommendation module comprises an input means for collecting data relating to a user and a means for determining the recommendation level for each scenario from a combination of the input data and information from a current local time slot.

[0026] In a preferred embodiment of the invention, the data relating to The user includes a list of parameters chosen from a chronotype, a wake-up time and / or a bedtime and a time difference.

[0027] In a preferred embodiment of the invention, the device comprises a user interface supported in software on electronic equipment which communicates remotely with the control module.

[0028] As used herein, the term "LED" or "LED" should be understood to include any light-emitting diode or other type of carrier injection / junction-based system capable of generating radiation in response to an electrical signal. Thus, the term LED includes, but is not limited to, various semiconductor-based structures that emit light in response to a current, light-emitting polymers, organic light-emitting diodes (OLEDs), light-emitting strips, etc.In particular, the term LED refers to light-emitting diodes of all types (including semiconductor and organic light-emitting diodes) that can be configured to generate one or more radiations in the infrared spectrum, the ultraviolet spectrum, and various parts of the visible spectrum (generally comprising radiation wavelengths ranging from about 400 nanometers to about 700 nanometers). Examples of light-emitting diodes include, but are not limited to, various types of infrared diodes, ultraviolet diodes, red diodes, blue diodes, green diodes, yellow diodes, amber diodes, orange diodes, and white diodes.It should also be noted that LEDs can be configured and / or controlled to generate radiation having different bandwidths (e.g., full width at half maximum, or FWHM) for a given spectrum (e.g., narrow bandwidth, broad bandwidth) and a variety of dominant wavelengths within a given general color categorization.

[0029] The term "light source" shall be understood to refer to one or more radiation sources, including, but not limited to, LED-based sources (including one or more LEDs as defined above), incandescent sources (e.g., filament lamps, halogen lamps), fluorescent sources, phosphorescent sources, high-intensity discharge sources (e.g., sodium vapor, mercury vapor, and metal halide lamps), lasers, other types of electroluminescent sources, pyroluminescent sources (e.g., flames), candle lamps, etc., flames), candle luminescent sources (e.g., gas mantles, carbon arc radiation sources), photoluminescent sources (e.g., gas discharge sources), cathode luminescent sources using electron saturation,galvanoluminescent sources, crystalloluminescent sources, cineluminescent sources, sources, thermoluminescent, triboluminescent sources, sonoluminescent sources, radioluminescent sources, and luminescent polymers.

[0030] A given light source may be configured to generate electromagnetic radiation in the visible spectrum, outside the visible spectrum, or a combination of both.

[0031] The term "spectrum" should be understood to mean one or more frequencies (or wavelengths) of radiation produced by one or more light sources. Accordingly, the term "spectrum" refers to frequencies (or wavelengths) not only in the visible range, but also to frequencies (or wavelengths) in the infrared, ultraviolet, and other areas of the overall electromagnetic spectrum. Similarly, a given spectrum may have a relatively narrow bandwidth or a relatively broad bandwidth. It should also be noted that a given spectrum may be the result of a mixture of two or more other spectra (e.g., a mixture of radiation emitted respectively by several light sources).

[0032] For purposes of this disclosure, the term "color" is used interchangeably with the term "spectrum." However, the term "color" is generally used to refer to a property of radiation that is perceptible to an observer (although this use is not intended to limit the scope of this term). It should also be noted that the term "color" can be used in connection with both white light and non-white light.

[0033] The term "color temperature" essentially refers to a particular color content or shade (e.g., reddish, bluish) of white light. The color temperature of a given radiation sample is generally characterized by the temperature in degrees Kelvin (K) of a blackbody radiator that emits essentially the same spectrum as the radiation sample in question. Lower color temperatures generally indicate white light having a larger red component or a "warmer feel," while higher color temperatures generally indicate white light having a larger blue component or a "cooler feel."For example, fire has a color temperature of about 1800 degrees Kelvin, a typical incandescent light bulb has a color temperature of about 2848 degrees Kelvin, early morning daylight has a color temperature of about 3000 degrees Kelvin, and an overcast midday sky has a color temperature of about 10,000 degrees Kelvin.

[0034] The terms "lighting device" or "luminaire" are used interchangeably herein to refer to an implementation or arrangement of one or more lighting units in a particular form factor, assembly, or package. The term "lighting unit" is used herein to refer to a device comprising one or more light sources of the same or different types. A given lighting unit may have a variety of mounting arrangements for the light source(s), housing arrangements and shapes, and / or electrical and mechanical connection configurations. In addition, a given lighting unit may optionally be associated with (e.g., include, be coupled to, and / or packaged with) various other components (e.g., control circuitry) relating to the operation of the light source(s). An "LED-based lighting unit" is a lighting unit that comprises one or more LED-based light sources as described above, alone or in combination with other non-LED-based light sources.A "multi-channel" lighting unit means an LED-based or non-LED-based lighting unit that includes at least two light sources configured to respectively generate different radiation spectra, each different source spectrum being designable as a "sub-channel" of the multi-channel lighting unit.

[0035] The term "controller" is used herein generally to describe various apparatus relating to the operation of one or more light sources. A controller may be implemented in many ways (e.g., with specialized hardware) to perform the various functions described herein. A "processor" is an example of a controller that uses one or more microprocessors that can be programmed using software (e.g., microcode) to perform the various functions described herein. A controller may be implemented with or without a processor, and may also be implemented as a combination of dedicated hardware to perform certain functions and a processor (e.g., one or more programmed microprocessors and associated circuitry) to perform other functions.Examples of controller components that may be employed in various embodiments of the present disclosure include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs).

[0036] In various implementations, a processor or controller may be associated with one or more storage media (generically referred to herein as "memory", e.g., volatile and non-volatile computer memory such as RAM, PROM, EPROM and EEPROM, floppy disks, compact disks, optical disks, magnetic tapes, etc.). In some embodiments, the storage media may be encoded with one or more programs that, when executed by one or more processors and / or controllers, perform at least some of the functions described herein. Various storage media may be fixed within a processor or controller or may be transportable, such that the program(s) therein stored may be loaded into a processor or controller to implement various aspects of the present invention.

[0037] The terms software, program, or computer program are used herein in a generic sense to refer to any type of computer code (e.g., software or microcode) that can be used to program one or more processors or controllers.

[0038] The term "user interface" as used herein refers to an interface between a human user or operator and one or more devices that enables communication between the user and the device(s). Examples of user interfaces that may be used in various implementations of the present disclosure include, but are not limited to, switches, potentiometers, buttons, dials, sliders, a mouse, a keyboard, a keypad, various types of game controllers (e.g., joysticks), track balls, display screens, various types of graphical user interfaces, touchscreens, microphones, and other types of sensors that can receive some form of human-generated stimulus and generate a signal in response to that stimulus.

[0039] The invention will be better understood and its advantages will appear better, on reading the detailed description which follows, of embodiments shown as non-limiting examples. The description refers to the appended drawings in which:

[0040] [Fig-1] [Fig.l] is a perspective view of a circadian lighting system;

[0041] [Fig.2] [Fig.2] is an illustration of two graphs corresponding to the evolution respectively of a luminous illuminance expressed in lux (2A) and at a color temperature expressed in Kelvin (2B) as a function of time in minutes for a first lighting scenario;

[0042] [Fig.3] [Fig.3] is an illustration of two graphs corresponding to the evolution respectively of a luminous illuminance expressed in lux (3A) and a color temperature expressed in Kelvin (3B) as a function of time in minutes for a second lighting scenario;

[0043] [Fig.4] [Fig.4] is an illustration of two graphs corresponding to the evolution respectively of a luminous illuminance expressed in lux (4A) and a color temperature expressed in Kelvin (4B) as a function of time in minutes for a third lighting scenario. Detailed description of the invention

[0044] [Fig. 1] shows a circadian lighting system. This system is designated by the general reference 10.

[0045] As illustrated in [Fig.l], the system 10 includes a circadian lighting device 20. The device 20 is a circadian lighting device with tunable light source configured to provide a plurality of lighting scenarios for synchronizing an individual's biological clock. In particular, the device 20 is configured to emit a light source 200 whose color temperature can be modified as a function of time.

[0046] In a manner known per se, the light source 200 is the result of mixing the light generated by a plurality of light-emitting units 210 which will be described below in more detail. In the preferred embodiment of the invention, each unit 210 comprises at least one light element, for example a light-emitting diode (LED), and preferably comprises a plurality of light elements for each unit 210.

[0047] The lighting scenarios may consist more specifically but not exclusively of synchronization of a biological clock (light therapy), stimulation of the body in preparation for a sporting or intellectual challenge, shifting of the biological clock in anticipation of a future trip or recovery from jet lag linked to a recent trip, a protocol for optimizing concentration, intellectual or physical performance and neurocognitive capacities, or an aid to falling asleep.

[0048] In particular, the device 20 comprises a module 220 for controlling or controlling the light power of the lighting units 210 independently of one another in order to obtain a spectral weight of the units 210, variable as a function of time, by varying the light power of each of the units 210 between predefined maximum and minimum values.

[0049] Further, preferably, the control module 220 comprises an addressing unit 222 connected to the units 210 and each unit 210 comprises a unique address which may be static or dynamic.

[0050] The control module 220 is provided for example to transmit control signals comprising control information for each light unit 210 to the addressing unit 222, for example according to a predefined communication protocol known to those skilled in the art. Each control signal comprises for example a data structure comprising control instructions, an address and useful data. In the preferred embodiment of the invention, the control module 220 comprises a processor for executing software instructions for generating control signals for the units 210. The control module 220 comprises a memory for storing the software instructions for execution by the processor.

[0051] Preferably, the addressing unit 222 comprises an integrated circuit or a microcontroller connected to the light elements of the same unit 210. Furthermore, the addressing unit 222 may comprise one or more electrical energy distribution buses. between each of the light element units 210 in order to allow control of the luminous flux of each of the units 210.

[0052] Preferably, the control module 220 further comprises a processor for executing software instructions for controlling the parameters of the light elements of each unit 210. For example, the control module 220 comprises a memory for storing the software instructions for execution by the processor.

[0053] In particular, the device 20 comprises a first white light emitting unit 212. This first unit 212 emits light whose light spectrum extends mainly in a wavelength range between 400 nm and 800 nm.

[0054] According to the invention, the first unit 212 comprises a plurality of light elements each emitting a unitary light flux towards a surface to be illuminated.

[0055] Preferably, the first unit 212 is formed by a combination of at least two groups 212A, 212B or sub-channels of light elements, here light-emitting diodes: a first group or sub-channel 212A of light-emitting diodes emitting a warm white type light with a color temperature of approximately 2700K and a second group or sub-channel 212B of light-emitting diodes emitting a cold white type light with a color temperature of approximately 6500K. These sub-channels 212A and 212B can be controlled independently by the control module 220.

[0056] Furthermore, according to the invention, the device 20 comprises a second blue light emission unit 214 whose light spectrum forms a narrow peak and whose peak summit is between 400 and 500 nm forming a second so-called stimulation unit. This peak is preferably centered around 490 nm, with a margin of plus or minus 5 nm around this value. Preferably, by narrow peak, it is meant that the width at half-height of the narrow peak is between 20 and 50 nm. The preferred value of 490 nanometers corresponds to a maximum sensitivity of the non-visual receptor cells or melanopsin glands of a human being.

[0057] More specifically, the light power emitted by the second unit 214 is always less than or equal to 35% of the total power emitted by the light source 200 of the device 20. This makes it possible to optimize the color rendering of the device 20 without distorting the white color of the light emitted by the source 200 while allowing effective action on the non-visual receptor cells.

[0058] Furthermore, in a preferred embodiment of the invention, the device 20 further comprises a third unit 216 whose light spectrum is relatively enriched with wavelengths greater than 560 nm and relatively devoid of wavelengths less than 560 nm. Preferably, the light spectrum of the third unit 216 is formed by a peak centered on a wavelength greater than 560 nm, preferably centered on 590 nm (with a margin of plus or minus 5 nm around this value), with a peak width between 20 and 50 nm. This unit 216 makes it possible to activate the visual system but has no effect on the non-visual melanopsin receptor cells of a human being. The amber light emitted by this third unit 216 allows the human body to naturally secrete melatonin by inhibiting the melanopsin receptor cells.

[0059] Preferably, in order to take into account the ultradian rhythm of the human being, the duration of a scenario is between 80 minutes and 100 minutes, preferably 90 minutes.

[0060] For example, the control module 220 comprises means for generating software instructions for controlling the light source 200 from a data frame of results of a set of data for evaluating a user profile.

[0061] Furthermore, preferably, the device 20 preferably comprises a terminal 30 for remote control of the module 220 for controlling the device 20. Preferably, the device 20 comprises a user interface 40, supported for example in software by the remote control terminal 30.

[0062] The control module 220 comprises means for generating control signals for the lighting units 210 as a function of a data frame generated following the selection by an operator of a scenario from a plurality of predetermined scenarios. These software instructions allow, for example, the generation of control signals addressed to the addressing unit 222 and then to the units 210. The user interface 40 is supported in software on the external electronic equipment 30 which communicates with the device 20. The control module 220 comprises a processor for executing software instructions for generating control signals for the units 210. Alternatively, the user interface 40 can be integrated into the same packaging case of the device 20 without a remote control terminal.

[0063] For example, the software instructions are generated from the user interface 40 of the device 20 allowing an operator to select the power adjustment parameters of each unit 210 according to a user profile. Preferably, the user interface 40 is supported in software on a tablet 30. The tablet 30 communicates for example with the control module 220 by a wired or wireless link (for example by Bluetooth® or by WiFi).

[0064] In a preferred embodiment of the invention, the device 20 comprises a recommendation module configured to generate a recommendation level for each scenario among the plurality of predetermined scenarios with a time slot for application of each of the scenarios.

[0065] Preferably, said recommendation module comprises an input means for collecting data relating to a user and a means for determining a scenario from a combination of the input data and information from a current local time slot. The determination means comprise, for example, a correspondence table taking as input, on the one hand, the user data and the time slots of a day and providing, as output, recommendation levels for the three (or more) scenarios.

[0066] The data relating to the user includes, for example, a list of parameters chosen from a chronotype (morning, evening or mixed), a wake-up time and / or a bedtime, a time difference linked to crossing several time zones towards the East or towards the West and a sleep deficit.

[0067] In a preferred embodiment of the invention, the user interface 40 comprises a plurality of icons each representing a scenario. In the example illustrated in [Fig. 1], the user interface 40 comprises first 42, second 44 and third 46 icons corresponding respectively to a wake-up scenario, a dynamic relaxation scenario and a recovery scenario which will be detailed below.

[0068] The recommendation module comprises, for example, visual means for displaying the icons differently from each other, for example highlighting or displaying a recommendation score on a scale of 0% to 100% associated with each icon.

[0069] We will now describe three scenarios for synchronizing a user's biological clock.

[0070] Preferably, whatever the scenario, initially, the light source 200 is spectrally tuned preferably to a warm white reception light: for example, illuminance of 100 lux and warm white color temperature of 2700K.

[0071] In a first waking scenario, the variation in color temperature is represented on curve 2B and the variation in illumination is represented on curve 2A. During a first period T1, the units 212A and 216 of warm white light and amber light respectively are activated so that the color temperature decreases until reaching a color temperature of 2100K. During this period T1, the light emitted by the source 200 tends to reproduce sunrise or dawn, which allows the individual to synchronize his biological clock with the start of the morning. Then, during a period T2, the amber light unit 216 is deactivated and the sub-channel of the 6500K white light unit 212B is activated so that the color temperature of the source 200 increases from a temperature of 2700K to 6500K.

[0072] Further, the power of the cyan light unit 214 is gradually increased from a substantially zero value until reaching a maximum value less than 35% of the total power of the light source 200 in a period T3. Preferably, the control module 220 is configured to gradually vary the light power of the second unit 214 from zero power to a maximum power corresponding to at most 35% of the total power.

[0073] In a dynamic relaxation scenario, the variation in the color temperature is represented on the curve 4B and the variation in the corresponding illumination is represented on the curve 4A. In this scenario, the control module 220 is configured to vary the light power of the second unit 214 between a zero value and a maximum power value according to a pulse train profile. For example, for a treatment duration of 90 minutes, the pulse train profile comprises between four and eight pulses, here five pulses.The pulses oscillate between a color temperature of approximately 2100 Kelvins (activation of the amber unit 216 and deactivation of the cyan light unit 214) and a color temperature of approximately 6000 Kelvins (activation of the cyan light unit 214 and deactivation of the light of the amber unit 216). The white light unit 212 is preferably kept activated during this scenario. In particular, the maximum power value of the light emitted by the unit 214 is always less than 35% of the total power of the light source 200. Preferably, the value of the maximum power of the light 214 corresponds to 30% of the total power of the source 200.

[0074] Finally, in a third so-called recovery scenario, the variation of the temperature . of color is represented on curve 3B and the variation of the corresponding illuminance in lux is represented on curve 3A. Preferably, in this scenario, the control module 220 is configured to vary the light power of the first unit 212 to a substantially zero power during a period T1 and to maintain only the light power of the third unit 216 at a non-zero value during a period T2. During a period T3, the three units 212 to 216 are gradually activated to gradually increase the color temperature from 1800K to 4000K. The use of increasingly amber light during the period T2 helps to accompany the body in the secretion of melatonin, which will promote relaxation.

[0075] We will now describe the main aspects of operation of the lighting device 20, in relation to a user wishing to benefit from a light therapy session in relation to his past or future activity.

[0076] Initially, an operator retrieves the user's data: chronotype (morning, evening or mixed), average sleep time, sleep deficit and / or past or future jet lag. The user's chronotype can be determined, for example, according to the preferred time sleep start time and the user's preferred wake-up time. For the jet lag event, the operator indicates, for example, a number of time zones of offset to the East or to the West crossed by the user. The operator enters this data via, for example, the user interface 40.

[0077] The operator also indicates via the user interface 40 the current local time slot (for example 9 a.m.-11 a.m., 1 p.m.-1 p.m., 1 p.m.-3 p.m., 3 p.m.-5 p.m., or 5 p.m.-7 p.m.). This current local time slot can also be calculated automatically by retrieving a current local time from an internal clock of the device 20. The recommendation module then calculates for each scenario a recommendation score which is displayed on the user interface 40 with a recommended time slot for each scenario.

[0078] The cyan color unit 214 of the device 20 is activated in each lighting scenario and makes it possible to artificially accentuate the stimulation of the non-visual pathways of the human body, which directly impacts the secretion of hormones.

[0079] Of course, other embodiments are conceivable without departing from the scope of the invention. Thus, various modifications can be made by those skilled in the art to the invention which has just been described by way of example.

Claims

Claims

1. Circadian lighting device (20) comprising a light source (200) tunable to provide a plurality of predetermined lighting scenarios, characterized in that the source (200) comprises a first unit (212) of white light whose light spectrum extends mainly in a wavelength range between 400 nm and 800 nm and a second unit (214) of blue light whose light spectrum forms a narrow peak whose summit is between 400 and 500 nm and in that the device (20) comprises a module (220) for controlling the light power of the two units (210; 212, 214) independently of each other in order to obtain a spectral mixing ratio of the two units, variable as a function of time, by varying the light power of each of the units (210;212, 214) between maximum and minimum values, the light power emitted by the second unit (214) always being less than or equal to 35% of the total power emitted by the light source (200).;

2. Device (20) according to the preceding claim, wherein in a stimulation scenario, the control module (220) is configured to gradually vary the light power of the second unit (214) from zero power to a maximum power corresponding to at most 35% of the total power of the light source (200).

3. A device (20) according to any preceding claim, wherein the first white light unit (212) comprises a first sub-channel (212A) of warm white light with a color temperature around 6500 Kelvin and a second sub-channel (212B) of cool white light with a color temperature around 2700 Kelvin.

4. Device (20) according to any one of the preceding claims, in which the control module (220) is configured to vary the light power of the second unit (214) between a zero value and a maximum value according to a pulse train profile, for example with a repetition period of between 12 minutes and 18 minutes.

5. Device (20) according to the preceding claim, in which the source (200) comprises a third unit (216) whose light spectrum is relatively enriched with wavelengths greater than 560nm and rela- tively devoid of wavelengths below 560 nm.

6. Device (20) according to the preceding claim, wherein, in a recovery scenario, the control module (220) is configured to vary the light power of the first unit (210) to a substantially zero power and to maintain only the light power of the third unit (216) at a non-zero value.

7. Device (20) according to any one of the preceding claims, wherein the duration of a scenario is between 80 minutes and 100 minutes, preferably 90 minutes.

8. Device (20) according to any one of the preceding claims, in which, the device (20) comprising a user interface (40), the control module (220) comprises means for generating the control signals for the lighting units (210; 212, 214, 216) as a function of a data frame generated following the selection by an operator of a scenario from a plurality of predetermined scenarios.

9. Device (20) according to any one of the preceding claims, comprising a recommendation module configured to generate a recommendation level for each lighting scenario and a recommended time slot for applying each scenario.

10. Device (20) according to the preceding claim, wherein said recommendation module comprises input means for collecting data relating to a user and means for determining the recommendation level for each scenario from a combination of the input data and a current local time slot.

11. Device (20) according to the preceding claim, in which the data relating to the user comprises a list of parameters chosen from a chronotype, a wake-up time and / or a bedtime and a time difference.

12. A device (20) according to any preceding claim, comprising a user interface (40) supported in software on electronic equipment (30) which communicates remotely with the control module (220).

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