EP4646551A1

EP4646551A1 - Improved artificial skylight

Info

Publication number: EP4646551A1
Application number: EP23817462.7A
Authority: EP
Inventors: Ties Van Bommel; Martinus Hermanus Wilhelmus Maria Van Delden
Original assignee: Signify Holding BV
Current assignee: Signify Holding BV
Priority date: 2023-01-02
Filing date: 2023-12-05
Publication date: 2025-11-12
Also published as: CN120435635A; WO2024146726A1; JP2026503994A

Abstract

The invention may provide a light generating system (1000) comprising a lighting module (1500); wherein the lighting module (1500) comprises a first light generating device (110), a second light generating device (120), and a light exit window (1100); wherein the light generating system (1000) is configured to provide lighting module light (1501) via the light exit window (1100); wherein the light exit window (1100) has a window perimeter (PO) and comprises: (i) a first light emitting surface part (1110) having a first perimeter (P1), and (ii) a second light emitting surface part (1120) having a second perimeter (P2); the second light emitting surface part (1120) has an ellipse-like cross-sectional shape; wherein the first light generating device (110) is configured to generate first device light (111) via the first light emitting surface part (1110); the second light generating device (120) configured to generate second device light (121) via the second light emitting surface part (1120); wherein the first device light (111) is white light having a first correlated color temperature CCT1 of at maximum 8000 K; the second device light (121) is (i) blue light or (ii) white light having a second correlated color temperature CCT2 of at least 5000 K; wherein when both the first device light (111) and the second device light (121) are white light, then CCT2-CCT1>500 K; and wherein both the first perimeter (P1) and the second perimeter (P2) touch the window perimeter (P0) or partly coincide with the window perimeter (P0).

Description

Improved artificial skylight

FIELD OF THE INVENTION

The invention relates to a light generating system. The invention further relates to an indoor space comprising such light generating system.

BACKGROUND OF THE INVENTION

Light emitting modules are known in the art. US2013249407, for instance, describes a first LED group including a plurality of LEDs regularly arranged in a toric shape on the circumference of a center of an approximately rectangular substrate which is formed of ceramics. In addition, the first LED group including the plurality of LEDs is entirely covered in a toric shape with a sealing member. In addition, a second LED group including a plurality of LEDs is regularly arranged in a grid shape in the vicinity of the center of the approximately rectangular substrate. In addition, the LED group including the plurality of LEDs is entirely covered with a sealing member. In addition, the sealing member entirely covers the inside of the toric portion of a first region.

SUMMARY OF THE INVENTION

In current times, people may have to spend a lot of time indoors especially in situations where people may have to work or attend school from a home environment. Hence, it is very beneficial to have access or exposure to natural daylight in such environment. Natural daylight has a positive effect on an individual’s health, especially in the production of Vitamin-D. Further, natural light may become increasingly important in the future where the current trend appears to promote working indoors. A solution may be the use of an artificial skylight which may provide an illusion of sunlight. Artificial skylights may provide emulation of at least certain aspects of an outdoor environment in an indoor environment. The demand for artificial skylights is increasing due to its beneficial properties for human wellbeing. Since people tend to spend a majority of their day indoors, which may remove them from natural daylight, there is an interest in creating artificial light, which may simulate the appearance and light of a natural window or skylight. Thus, there appears to be a desire for (improved) artificial skylights, or other type of lighting devices or light generating systems, having enhanced natural appearance.

Hence, it is an aspect of the invention to provide an alternative system to generate light, which preferably further at least partly obviates one or more of abovedescribed drawbacks. The present invention may have as object to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

Hence, in a first aspect the invention provides a light generating system comprising a lighting module (“module”), such as an artificial skylight. Especially, the lighting module may comprise a first light generating device, a second light generating device, and a light exit window. In embodiments, the light generating system may be configured to provide lighting module light via the light exit window. Especially, the light exit window may have a window perimeter (P0) and may comprise: (i) a first light emitting surface part having a first perimeter (Pl), and (ii) a second light emitting surface part having a second perimeter (P2). Further, in embodiments, the second light emitting surface part may have an ellipse-like cross-sectional shape. In embodiments, the first light generating device may be configured to generate first device light via the first light emitting surface part. Especially, the second light generating device may be configured to generate second device light via the second light emitting surface part. Furthermore, in embodiments, the first device light may be white light having a first correlated color temperature CCT1 of at maximum 8000 K. The second device light may especially be (i) blue light or (ii) white light having a second correlated color temperature CCT2 of at least 5000 K. In embodiments, when both the first device light and the second device light are white light, then it may especially apply that CCT2-CCTl>500 K. In embodiments, both the first perimeter (Pl) and the second perimeter (P2) may touch the window perimeter (P0) or partly coincide with the window perimeter (P0). Hence, in specific embodiments, the invention provides a light generating system comprising a lighting module; wherein the lighting module comprises a first light generating device, a second light generating device, and a light exit window; wherein the light generating system is configured to provide lighting module light via the light exit window; wherein the light exit window has a window perimeter (P0) and comprises: (i) a first light emitting surface part having a first perimeter (Pl), and (ii) a second light emitting surface part having a second perimeter (P2); the second light emitting surface part has an ellipse-like cross-sectional shape; wherein the first light generating device is configured to generate first device light via the first light emitting surface part; the second light generating device configured to generate second device light via the second light emitting surface part; wherein the first device light is white light having a first correlated color temperature CCT1 of at maximum 8000 K; the second device light is (i) blue light or (ii) white light having a second correlated color temperature CCT2 of at least 5000 K; wherein when both the first device light (111) and the second device light (121) are white light, then CCT2-CCTl>500 K; and wherein both the first perimeter (Pl) and the second perimeter (P2) touch the window perimeter (P0) or partly coincide with the window perimeter (P0).

In this way, the invention may provide an improved lighting module, such as an artificial skylight. With this system one may - amongst others - create a (virtual) connection to the outside world by mimicking the natural daylight from a (simulated) lighting module having two different spectral power distributions such as e.g. to simulate the natural blueish light scattered from the sky as well as sunlight. Also, with the control of the spectral power distributions (such as controlling) color temperatures, the illusion of different kinds of weather conditions may be provided for e.g. overcast weather. This invention can be used in spaces where access to daylight is limited or absent, such as in office spaces, hospitality areas, and especially spaces deprived from access to natural light, such as underground spaces and control rooms. The invention may be used to help people maintain a connection to the dynamic natural world outside, thus making indoor environments with little or no daylight access more appealing by creating a realistic illusion of a skylight (or “roof light”) or window. Further, this invention allows a relatively shallow solutions, whereas prior art systems may have substantial depths.

As mentioned before, in embodiments, the invention provides a light generating system comprising a lighting module. In embodiments, the lighting module light may provide light that mimics the natural light observed on a clear day. This may especially comprise a combination of both blue light which results from the scattering of sunlight in the atmosphere, and white light which may simulate direct sunlight. Alternatively, in embodiments, the lighting module may provide a combination of white light of two different color temperatures. Hence, in embodiments, the lighting module may provide light that simulates such natural skylight. Further, in specific embodiments the lighting module may provide light that mimics the natural light observed during a cloudy day, or during sunset or sunrise.

Herein, the lighting module may especially be designed as artificial skylight, i.e. a lighting module to be functionally coupled to a ceiling. However, other applications, like an artificial window, functionally coupled to a wall, are herein also encompassed. Hence, the term “lighting module” may in embodiments refer to an artificial skylight (and may in other specific embodiments refer to another type of lighting module).

Especially, the term “artificial skylight” (which may also be indicated as “artificial roof light”) may in embodiments be a window-like artificial light generating device. Such artificial skylight may form e.g. part of a ceiling (or root) (of a building) or may be functionally coupled to the ceiling (or root), e.g. for mimicking daylight.

Herein, the term “functionally coupled” may in embodiments refer to a physical connection or mechanical connection between at least two elements, such as via one or more of a screw, a solder, an adhesive, a melt connection, a click connection, etc. The terms “physical connection” and “mechanical connection” may herein interchangeably be used. The terms “physical connection” and “mechanical connection” may thus also refer to an adhesive connection. Alternatively or additionally, the term “functionally coupled” may in embodiments refer to an electrical conductive connection between at least two connections.

Especially, functionally coupled in the present context may imply that the lighting module is associated to a wall or ceiling. Further, in the present context this may imply that the lighting module is coupled to a source of electrical power, such as the mains.

In embodiments, the lighting module may comprise a first light generating device, a second light generating device, and a light exit window. Especially, the light generating system may be configured to provide lighting module light via the light exit window. Therefore, in embodiments, the light exit window may be light transmissive. The light exit window may comprise light transmissive materials such as glass, PMMA, PET, PC, etc. Embodiments of such are discussed further below.

Especially, in embodiments the light generating system may provide lighting module light via the light exit window, meaning that the light generating system may provide light from either one (or both) the first light emitting surface part or the second light emitting surface part, especially from both.

In embodiments, the light exit window may have a window perimeter (P0). Furthermore, in embodiments, the light exit window may comprise a first light emitting surface part having a first perimeter (Pl), and a second light emitting surface part having a second perimeter (P2). Especially, in embodiments the window perimeter may essentially be defined by a part of the first perimeter (Pl) and a part of the second perimeter (P2). Further, especially in embodiments the parts of the first perimeter (Pl) and the second perimeter (P2) that do not contribute to the window perimeter, may be essentially overlapping parts. Hence, in embodiments, both the first perimeter (Pl) and the second perimeter (P2) may touch the window perimeter (P0) or partly coincide with the window perimeter (P0).

The two aforementioned light emitting surface parts, i.e. the first light emitting surface part and the second light emitting surface part, may in embodiments divide the surface of the light exit window into essentially two regions each having an associated perimeter and surface area. Typically, in embodiments, the first light emitting surface part and the second light emitting surface part may especially divide the light exit window into two different regions, and hence, the first light emitting surface part and the second light emitting surface part may especially share a part of their boundaries with the light exit window.

In embodiments, the second light emitting surface part may have an ellipselike cross-sectional shape. An ellipse may especially be a closed shape surrounding two focal points, wherein the extent of the ellipse may be defined by a major and a minor axis. In embodiments, the second light emitting surface part may especially have an ellipse-like cross-sectional shape, that is, it may have a shape wherein a minor and a major axis may be defined but may not necessarily have a smooth boundary. Especially, the ends of the ellipselike cross-sectional shape may be sharp ends (as opposed to the smooth boundary of an ellipse) e.g. also referred to as lens shape. Embodiments of such are discussed further below. Further, the ellipse-like cross-sectional shape may have a first part of its perimeter touching the window perimeter (P0) or partly coinciding with the window perimeter (P0) and a second part of its perimeter touching the first perimeter (Pl) or partly coinciding with the first perimeter (Pl) of the first light emitting surface part.

As mentioned above, the first light generating device may in embodiments be configured to generate first device light (which may escape) via the first light emitting surface part. In embodiments, the second light generating device may be configured to generate second device light (which may escape) via the second light emitting surface part.

In embodiments, the first light emitting surface part and the second light emitting surface part may be separated such that they are not in mutual optical communication. Here, mutual optical communication between two elements may refer to an exchange (or transfer) of light between the two elements, or from one element to the other. Hence, in embodiments, the light escaping from the first light emitting surface part may not comprise second device light, and the light escaping from the second light emitting surface part may not comprise first device light. Downstream from the light exit window, beams of first device light and second device light may at least partly overlap, e.g. at some distance from the exit window. Hence, in the far field beams of first device light and second device light may at least partly overlap. However, essentially no first device light may escape from the second light emitting surface, and essentially no second device light may escape from the first light emitting surface.

Hence, in embodiments essentially all first device light escaping from the light generating system escapes via the first light emitting surface. Likewise, essentially all second device light escaping from the light generating system escapes via the second light emitting surface.

Especially, in embodiments the light generating system may be configured to generate system light comprising at least part of the first device light (emanating from the first light emitting surface) and at least part of the second device light (emanating from the second light emitting surface). Hence, in embodiments the first device light and the second device light may especially be generate simultaneously.

In embodiments, there may be a reflective separator between the first light emitting surface part and the second light emitting surface part to prevent mutual optical communication (between the first light emitting surface part and the second light emitting surface part).

Hence, in embodiments, the light generating system may provide lighting module light via the light exit window. Especially the lighting module light may comprise the first device light, or the second device light, or both (dependent upon the operational mode). Especially, however, in operational modes the lighting module light comprises both the first device light and the second device light.

In embodiments, the first device light may be white light having a first correlated color temperature CCT1 of at maximum 8000 K, such as at maximum 7000 K, especially at maximum 6000 K, more especially at maximum 5000 K. Further, in embodiments, the second device light may be (i) blue light or (ii) white light having a second correlated color temperature CCT2 of at least 5000 K, such as at least 6000 K, like especially at least about 8000 K. In further embodiments, it may even be higher, like at least about 10000 K, especially at least 12000 K. CCT here may refer to the correlated color temperature, which may be a color temperature scale used to categorize the color of light emitted by a light generating device, as known in the art. In embodiments, 1800 K < CCT1 < 8000 K, more especially 1800 K < CCT1 < 5000 K. Further, in embodiments, 5000 K < CCT2 < 20000 K, more especially 6500 K < CCT2 < 15000 K. The second device light may also be a combination of blue light and white light. Note that white light having a high CCT may (already) be blueish.

Note that even though the first correlated color temperature CCT1 may be at maximum 8000 K and a second correlated color temperature CCT2 of at least 5000 K, CCT1 and CCT2 are chosen such that CCT2>CCT1. Hence, with such a combination of the first device light and the second device light, the light generating system may in embodiments provide lighting module light. However, in embodiments, when (both) the first device light and the second device light may be white light, then CCT2-CCTl>500 K, such as CCT2- CCTl>1000 K, especially CCT2-CCTl>2000 K. In specific embodiments, CCT2- CCTl>3000 K, such as CCT2-CCTl>4000 K, more especially CCT2-CCTl>5000 K. In this way, the light generating device may especially provide lighting module light comprising light of at least two different CCT.

The terms “blue light” or “blue emission”, and similar terms, may especially relate to light having a wavelength in the range of about 440-490 nm (including some violet and cyan hues). In specific embodiments, the blue light may have a centroid wavelength in the 440-490 nm range. The term “white light”, and similar terms, herein, is known to the person skilled in the art. It may especially relate to light having a correlated color temperature (CCT) between about 1800 K and 20000 K, such as between 2000 and 20000 K, especially 2700-20000 K, for general lighting especially in the range of about 2000-7000 K, such as in the range of 2700 K and 6500 K.

Hence, in embodiments the first device light and the second device light may both be white light (having different CCTs’), whereas in other embodiments the first device light is white light and the second device light comprises blue light. Especially, in embodiments the second device light may have a dominant wavelength selected from the range of 400-490 nm, such as 420-470 nm.

Further, the light generating system may in embodiments comprise a housing, wherein the housing may comprise one or more walls. Especially, one of the walls of the housing may be light transmissive. More especially, such a wall may comprise the light exit window. As mentioned above, the light exit window may be transmissive for light (or light transmissive). Yet further, in embodiments, the light exit window may comprise a light transmissive material.

The light transmissive material is known to the skilled person as a material that allows light to be transmitted through it. The light transmissive material may be transmissive to light, wherein, in embodiments, transmissivity of light through the light transmissive material in a direction perpendicular to its surface may be at least 50%, such as at least about 75%, like in embodiments at least 90%, even more especially at least about 100%. Further, in embodiments, the light transmissive material may be a material such as glass or light transmissive polymeric material, such as PMMA, see (also) further below.

The light transmissive material may comprise one or more materials selected from the group consisting of a transmissive organic material, such as selected from the group consisting of PE (polyethylene), PP (polypropylene), PEN (polyethylene napthalate), PC (polycarbonate), polyurethanes (PU), polymethylacrylate (PMA), polymethylmethacrylate (PMMA) (Plexiglas or Perspex), polymethacrylimide (PMI), polymethylmethacrylimide (PMMI), styrene acrylonitrile resin (SAN), cellulose acetate butyrate (CAB), silicone, polyvinylchloride (PVC), polyethylene terephthalate (PET), including in an embodiment (PETG) (glycol modified polyethylene terephthalate), PDMS (poly dimethylsiloxane), and COC (cyclo olefin copolymer). Especially, the light transmissive material may comprise an aromatic polyester, or a copolymer thereof, such as e.g. one or more of polycarbonate (PC), poly (methyl)methacrylate (P(M)MA), polyglycolide or poly glycolic acid (PGA), polylactic acid (PLA), poly caprolactone (PCL), polyethylene adipate (PEA), polyhydroxy alkanoate (PHA), polyhydroxy butyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN). Especially, the light transmissive material may comprise polyethylene terephthalate (PET). Hence, the light transmissive material is especially a polymeric light transmissive material. However, in another embodiment the light transmissive material may comprise an inorganic material. Especially, the inorganic light transmissive material may be selected from the group consisting of glasses, (fused) quartz, transmissive ceramic materials, and silicones. Also hybrid materials, comprising both inorganic and organic parts may be applied. Especially, the light transmissive material comprises one or more of PMMA, transparent PC, or glass.

In embodiments, the light exit window may be translucent. Especially, the light exit window may be light diffusive / scattering. The latter may prevent that an observer may view from external through the light exit window into the housing, while allowing light to escape from the housing. Hence, especially in embodiments the light exit window is not fully transparent as it appears useful when at least part of the light escaping from the system is scattered in the light exit window.

Other walls of the housing, like side walls and/or a bottom (wall), may in embodiments be reflective, like especially diffuse reflective. Further, the housing may comprise one or more inner walls, which may be used to (optically) separate a space upstream from the first light emitting surface part from a space upstream from the second light emitting surface part. In this way, essentially no first device light may escape from the second light emitting surface, and essentially no second device light may escape from the first light emitting surface.

As indicated above, the housing may be relatively shallow. Hence, with a relatively shallow device, e.g. a skylight, may be obtained. For instance, the height may be a few mm up to a few cm or larger, like selected from the range of 1-100 mm, like 2-100 mm, such as 4-100 mm, like 4-80 mm, such as at maximum 50 mm, such as for instance in the range of 5-20 mm.

As mentioned above, the light exit window may comprise two light emitting surface parts, the first light emitting surface part and the second light emitting surface part.

Especially, the second light emitting surface part (comprised by the light exit window) may in embodiments have an ellipse-like shape. An ellipse-like shape may especially resemble an ellipse in certain features, such as having an elongated cross-sectional shape which may be characterized by a major and a minor axis. Further, in embodiments, the ellipse-like shape may be enclosed by one or more curved boundaries. However, the ellipselike shape may in embodiments comprise two pointed ends. This may, in embodiments, distinguish the ellipse-like shape from an ellipse. The ellipse-like shape may in embodiments be defined as a shape that is the mutual area between the intersection of two circles. Hence, the shape may especially be defined by two curves (i.e., the arcs from two circles) and may have sharp pointed ends (i.e., at the two points of intersection of the two circles).

In embodiments, the second light emitting surface part may have a lens-like cross-sectional shape. As mentioned above, a lens may be a convex shape bound by two arcs joined at their endpoints. Alternatively, in embodiments, the same shape may be formed by the union of two circular disks. Note that, in embodiments, the two arcs that may form the lens-like cross-sectional shape may be the mutual area formed by the intersection of two circles. Especially, the radii of the two circles may be different. Therefore, the curvature of the arcs that may form the lens-like cross-sectional shape may be different. Hence, in some embodiments, the lens-like cross-sectional shape may have a plane of symmetry passing through the two sharp ends of the lens-like cross-sectional shape. However, in other embodiments, the lens-like shape may not have a plane of symmetry passing through the two sharp ends of the lens-like cross-sectional shape. Yet further, in embodiments, the lens-like shape may also be the mutual area formed by the intersection of other curved shapes such as ovals, ellipses, egg-shaped cross-sections, etc. Further, in embodiments, the light exit window may have a circular cross-sectional shape. However, in other embodiments, the light exit window may comprise a cross-sectional shape such as an oval, ellipsoidal, egg-shaped, etc.

In embodiments, the light exit window may have a plane of symmetry (PS). Especially, the plane of symmetry (PS) may be a flat surface that may bisect the light exit window, such that the two halves of the light exit window are mirrored. More especially, such a bisection may provide two halves (each) comprising a part of (both) the first light emitting surface part and the second light emitting surface part. Hence, in specific embodiments, the light exit window has a circular cross-sectional shape; wherein the light exit window has a plane of symmetry (PS) intersecting both the first light emitting surface part and the second light emitting surface part.

In embodiments, the light exit window may especially be flat. Especially, the light exit window may have a surface area SAO. Further, in embodiments, the first light emitting surface part may comprise a first surface area SAI. Furthermore, in embodiments, the second light emitting surface part may comprise a second surface area SA2. Typically, in embodiments, the second surface area may be smaller than the first surface area. This may be advantageous in providing lighting module light as a larger first surface area (compared to the second surface area) may provide the advantage of outcoupling more first device light (compared to the second device light). Therefore, in embodiments, SA2<2*SA1, such as SA2<SA1, especially SA2<O.5*SA1. Further, in embodiments, the total surface area of the light exit window may be comprised entirely by the first surface area SAI and second surface area SA2. Especially, SAO = SAI + SA2. Note that these aforementioned surface areas may be defined in embodiments excluding the area occupied the boundaries of the surface areas SAI and SA2. However, in other embodiments, the first light emitting surface part and the second light emitting surface part may be separated by a reflective (or opaque) separator. In such embodiments, the majority of the surface area of the light exit window may be comprised by the first light emitting surface part and the second light emitting surface part, especially 0.98*SA0 < SAI + SA2, such as 0.95*SA0 < SAI + SA2, more especially 0.9*SA0 < SAI + SA2. Hence, especially 0.9*SA0 < SAI + SA2 < SAO.

Furthermore, in embodiments, the relationship between the first light emitting surface part and the second light emitting surface part may be defined in relation to their longest extent. In embodiments, the longest extent of the first light emitting surface part may be the diameter of the light exit window (when the light exit window is circular). In other embodiments, (where the light exit window has a non-circular cross section) the longest extent may be defined as the longest distance between two points on the boundary of the first light emitting surface part.

The longest extent of the first light emitting surface part may in embodiments be referred to as the first length LI. In embodiments, the longest extent of the second light emitting surface part may be the major axis of the ellipse-like shape (or lens-like cross- sectional shape). More especially, the longest extent of the second light emitting surface part may be referred to as the second length L2.

Note that in embodiments, the first length LI and the second length L2 may especially be defined parallel. Furthermore, in embodiments, L2<L1, such as L2<O.4*L1, especially L2<O.25*L1. Such embodiments may provide the advantage of outcoupling more first device light as compared to second device light. Hence, in specific embodiments, the first light emitting surface part has a first surface area SAI; wherein the second light emitting surface part has a second surface area SA2; wherein SA2<SA1; wherein L2<O.4*L1; wherein the light exit window has a surface area SAO, wherein SAO=SA1+SA2.

As mentioned above, it may be desired to provide embodiments wherein the first device light is white light and the second device light is either blue or white light (though this may also include a combination of blue or white light). Hence, in embodiments, the second device light may be selected from a cooler color temperature as opposed to the first device light which may be selected from a warmer color temperature.

Especially, the first correlated color temperature CCT1 may be selected from the range 2700 K < CCT1 <6500 K, such as 3500 K < CCT1 <6500 K, especially 5000 K < CCT1 <6500 K. Furthermore, in embodiments, CCT1 may be selected in the range 2700 K < CCT1 <6000 K, such as 2700 K < CCT1 <5000 K, especially 2700 K < CCT1 <3500 K.

Especially, in embodiments, CCT2 may be selected from the range CCT2 > 6500 K, especially CCT2 > 8000 K, more especially CCT2 > 12000 K. Furthermore, in embodiments, CCT2 may be selected from the range 6500 K < CCT2 < 20000 K, such as 8500 K < CCT2 < 20000 K, especially 8500 K < CCT2 < 15000 K. In specific embodiments, 2700 K < CCT1 <6500 K, and CCT2 > 6500 K. As mentioned above, some embodiments may comprise first device light that may be white light and the second device light that may be (also) white light. In such embodiments, it may be advantageous to provide light comprising two correlated color temperatures that vary in color temperature according to CCT2-CCT1> 1000 K, such as CCT2-CCT1> 2000 K, especially CCT2-CCT1> 4000 K, more especially CCT2-CCT1> 8000 K. Hence, in this way, lighting module light may be provided such that the lighting module light comprises light having two different color temperatures.

In embodiments, the light generating system may comprise a first light chamber. Especially, the first light chamber may be an enclosed space, wherein one of the walls may in embodiments be the first light emitting surface part. Further, in embodiments, the other walls of the first light chamber may especially be reflective (for the respective device light). Further, in embodiments, the light generating system may comprise a second light chamber. Especially, the second light chamber may (also) be an enclosed space, wherein one of the walls may in embodiments be the second light emitting surface part. Further, in embodiments, the other walls of the light emitting surface part may be reflective (for the respective device light).

In embodiments, at least part of the first light generating device may be comprised by the first light chamber. Analogously, in embodiments, at least part of the second light generating device may be comprised by the second light chamber. Hence, first device light (generated by the first light generating device) may be outcoupled from the first light chamber via the first light emitting surface part. Similarly, second device light (generated by the second light generating device) may be outcoupled from the second light chamber via the second light emitting surface part.

Further, in embodiments, the first light chamber may not be in optical communication with the second light chamber (see also above). In embodiments, they may be separate chambers, separated by an opaque wall or a reflective wall. Especially, the first light chamber and the second light chamber may be separated by a (diffuse) reflector. Hence, in specific embodiments, the light generating device may comprise (i) a first light chamber, comprising the first light emitting surface part and enclosing at least part of the first light generating device, and (ii) a second light chamber, comprising the second light emitting surface part and enclosing at least part of the second light generating device; wherein the light chambers are not configured in mutual optical communication.

In embodiments, the light exit window may comprise an optical diffuser. The optical diffuser may especially provide diffuse light (such as by means of scattering). Particularly, the scattering of light may disrupt the aligned nature of light waves resulting in pseudo-random changes in phase of the light and thus, provide diffuse light. A beam of light may be desired in workplaces such as offices, schools, homes, etc. However, diffuse light may (also) be desired because of the soothing (i.e. less harsh) quality of light compared to exposure to a beam of light. Further, diffuse light may especially be useful in illuminating a space more evenly. In such embodiments, the optical diffuser may comprise (both) the first light emitting surface part and the second light emitting surface part.

In embodiments, the optical diffuser may comprise scattering particles embedded within. Such particles may especially scatter an incident beam of light and hence, provide diffuse light. Hence, in specific embodiments, the light exit window comprises an optical diffuser, wherein the optical diffuser comprises the first light emitting surface part and second light emitting surface part.

In embodiments, the first light chamber may comprise the first light generating device. In further embodiments, the first light chamber may comprise a plurality of first light generating devices. Similarly, in embodiments, the second light chamber may comprise the second light generating device. In further embodiments, the second light chamber may comprise a plurality of second light generating devices. Hence, in specific embodiments, the first light chamber comprises at least part of a plurality of first light generating devices and/or wherein the second light chamber comprises at least part of a plurality of second light generating devices.

In embodiments, the light generating device may comprise a first light guide. Especially, the first light guide may comprise the first light emitting surface part. Further, in embodiments, the light generating system may comprise a second light guide. Especially, the second light guide may comprise the second light emitting surface part. In embodiments, the first light guide may be configured in a light receiving relationship with the first light generating device. Further, in embodiments, the first light guide may comprise a first light emitting light guide surface from which during operation of the first light generating device, first device light emanates. Especially, the first light emitting surface part may be configured in a light receiving relationship with the first light emitting light guide surface or may comprise the first light emitting light guide surface.

Similarly, in embodiments, the second light guide may be configured in a light receiving relationship with the second light generating device. Especially, the second light guide may comprise a second light emitting light guide surface from which during operation of the second light generating device, second device light may emanate. Especially, the second light emitting surface part may be configured in a light receiving relationship with the second light emitting light guide surface or may comprise the second light emitting light guide surface. In embodiments, the light guides may not be configured in mutual optical communication. Especially, the first light guide and the second light guide may not be in mutual communication. Embodiments, such as this may provide flexibility in the physical location at which the first (or second) light generating devices may be configured in relation to the light exit window. In embodiments, the light guides may be separated by a specular reflector. However, in other embodiments, the light guides may (also) be separated by a diffusive reflector. Hence, in specific embodiments, the light generating system comprises a first light guide and a second light guide, wherein the first light guide is configured in a light receiving relationship with the first light generating device; wherein the first light guide comprises a first light emitting light guide surface from which during operation of the first light generating device first device light emanates; wherein the first light emitting surface part is configured in a light receiving relationship with the first light emitting light guide surface or comprises the first light emitting light guide surface; wherein the second light guide is configured in a light receiving relationship with the second light generating device; wherein the second light guide comprises a second light emitting light guide surface from which during operation of the second light generating device second device light emanates; wherein the second light emitting surface part is configured in a light receiving relationship with the second light emitting light guide surface or comprises the second light emitting light guide surface; and wherein the light guides are not configured in mutual optical communication. The first light guide and the second light guide may in embodiments comprise light outcoupling structures, to couple first device light and second device light, respectively, out from the respective first light guide and the second light guide.

As indicated above, first device light may escape from the first light emitting surface part and second device light may escape from the second light emitting surface part. However, in specific embodiments, in another operational mode of the light generating system, light different from the first device light may emanate from the first light emitting surface part and/or light different from the second device light may emanate from the second light emitting surface part. For instance, in an operational mode of the light generating system second device light may escape from the first light emitting surface part and first device light may escape from the second light emitting surface part. Alternatively or additionally, in another operational mode of the light generating system first device light may escape from the first light emitting surface part and light other than the second device light may escape from the second light emitting surface part. Alternatively or additionally, in another operational mode of the light generating system light different from the first device light may escape from the first light emitting surface part and second device light may escape from the second light emitting surface part. In embodiments, the light generating system may comprise an array of light generating devices, wherein the array comprises different types of light generating devices which may be (regularly) distributed over the array. In this way, light with different spectral power distributions may emanate from the same part of the array, dependent upon the (different) light generating devices that are applied. In embodiments, a first array may be configured upstream of the first light emitting surface part, allowing to generate first device light and light different from the first device light, respectively. In this way, different types of light may (respectively) emanate from the first light emitting surface part, dependent upon the operational mode of the light generating system. Alternatively or additionally, a second array may be configured upstream of the second light emitting surface part, allowing to generate second device light and light different from the second device light, respectively. In this way, different types of light may (respectively) emanate from the second light emitting surface part, dependent upon the operational mode of the light generating system.

In embodiments, one or more parts of the array of the light generating devices may be optically separated from one or more other parts of the array of the light generating devices. In this way, it may be possible to execute the operational mode wherein first device light may emanate from the first light emitting surface part and second device light may emanate from the second light emitting surface part. However, such system may also allow combining different parts over time, thereby allowing a control of the shape and/or size of the first light emitting part and the second light emitting part. Hence, in specific embodiments, the arrays may be separated by a reflective (or opaque) wall (see also above).

In embodiments, optics may be applied to essentially guarantee that first device light may emanate from the first light emitting surface part and/or the second device light may emanate from the second light emitting surface part.

In embodiments, the light generating system may further comprise a control system. Especially, the control system may control the operation of the first light generating devices. Furthermore, in embodiments, the control system may control the operation of the second light generating devices. In embodiments, the control system may be configured to (individually) control (or operate in a mode of operation), the one or more light generating devices.

The term “controlling” and similar terms especially refer at least to determining the behavior or supervising the running of an element. Hence, herein “controlling” and similar terms may e.g. refer to imposing behavior to the element (determining the behavior or supervising the running of an element), etc., such as e.g. measuring, displaying, actuating, opening, shifting, changing temperature, etc.. Beyond that, the term “controlling” and similar terms may additionally include monitoring. Hence, the term “controlling” and similar terms may include imposing behavior on an element and also imposing behavior on an element and monitoring the element. The controlling of the element can be done with a control system, which may also be indicated as “controller”. The control system and the element may thus at least temporarily, or permanently, functionally be coupled. The element may comprise the control system. In embodiments, the control system and element may not be physically coupled. Control can be done via wired and/or wireless control. The term “control system” may also refer to a plurality of different control systems, which especially are functionally coupled, and of which e.g. one control system may be a master control system and one or more others may be slave control systems. A control system may comprise or may be functionally coupled to a user interface.

The control system may also be configured to receive and execute instructions from a remote control. In embodiments, the control system may be controlled via an App on a device, such as a portable device, like a Smartphone or I-phone, a tablet, etc.. The device is thus not necessarily coupled to the lighting system, but may be (temporarily) functionally coupled to the lighting system.

Hence, in 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 lighting system may be a slave control system or control in a slave mode. For instance, the lighting system may be identifiable with a code, especially a unique code for the respective lighting system. The control system of the lighting system may be configured to be controlled by an external control system which has access to the lighting system on the basis of knowledge (input by a user interface of with an optical sensor (e.g. QR code reader) of the (unique) code. The lighting system may also comprise means for communicating with other systems or devices, such as on the basis of Bluetooth, Thread, WIFI, LiFi, ZigBee, BLE or WiMAX, or another wireless technology.

The system, or apparatus, or device may execute an action in a “mode” or “operation mode” or “mode of operation” or “operational mode”. The term “operational mode may also be indicated as “controlling mode”. Likewise, in a method an action or stage, or step may be executed in a “mode” or “operation mode” or “mode of operation” or “operational mode”. This does not exclude that the system, or apparatus, or device may also be adapted for providing another controlling mode, or a plurality of other controlling modes. Likewise, this may not exclude that before executing the mode and/or after executing the mode one or more other modes may be executed.

However, in embodiments a control system may be available, that is adapted to provide at least the controlling mode. Would other modes be available, the choice of such modes may especially be executed via a user interface, though other options, like executing a mode in dependence of a sensor signal or a (time) scheme, may also be possible. The operation mode may in embodiments also refer to a system, or apparatus, or device, that can only operate in a single operation mode (i.e. “on”, without further tunability).

Hence, in embodiments, the control system may control in dependence of one or more of an input signal of a user interface, a sensor signal (of a sensor), and a timer (or clock module). The term “timer” may refer to a clock and/or a predetermined time scheme.

In summary, in specific embodiments, the light generating system may further comprise a control system, wherein the control system is configured to (individually) control the first light generating device and the second light generating device in dependence of one or more of an input signal of a user interface, a sensor signal (of a sensor), and a timer.

In embodiments, the light generating system may (thus) comprise a sensor, wherein the sensor may be configured to generate a sensor signal in dependence of a presence of an object in a field of view of the sensor. Especially, the sensor may at least be configured to detect the presence of a human in the field of view of the sensor. In embodiments, the sensor may be selected from a group comprising a camera, a passive infrared sensor, an ultrasonic sensor, a microwave sensor, a time of flight sensor, and an audio sensor.

In embodiments, the sensor may comprise camera such as especially a digital camera or a LiDAR. In further embodiments, the sensor may comprise a passive infrared sensor. In embodiments, the sensor may comprise an ultrasonic sensor. In embodiments, the sensor may comprise an audio sensor. In embodiments, the sensor may comprise a microwave sensor. In embodiments, the sensor may comprise an IR sensor. In embodiments, the sensor may comprise a light sensor. In specific embodiments, the sensor may comprise a time of flight sensor. The sensor may generate a (corresponding) sensor signal, e.g. when observing a person or when observing a moving person. Hence, in specific embodiments, the light generating system further comprises a sensor, wherein the sensor is configured (i) to sense presence and/or movement of a human, and (ii) to generate a related sensor signal, and wherein the control system is configured to (individually) control the first light generating device and the second light generating device in dependence of an input signal of the sensor signal (of a sensor). Hence, in embodiments the control system may be configured to (individually) control the first light generating device and the second light generating device in dependence of one or more of a user interface, a sensor signal (of a sensor), and a timer.

The spectral power distributions of the first device light and the second device light may thus be different. In embodiments, the spectral power distribution of lighting module light outcoupled from the light exit window may be in dependence of the spectral power distribution of the first device light and/or the second device light outcoupled from the first light generating device and/or the second light generating device. Alternatively or additionally, the radiative flux of the first device light emanating from the first light emitting surface may be controlled in dependence of the radiative flux of the second device light emanating from the second light emitting surface. Further, one or more of the spectral power distribution of the first device light, the spectral power distribution of the second device light, the radiative flux of the first device light, and the radiative flux of the second device light may be controlled in dependence of one or more of a user interface, a sensor signal (of a sensor), and a timer. Especially, one or more of the spectral power distribution of the first device light, the spectral power distribution of the second device light, the radiative flux of the first device light, and the radiative flux of the second device light may be controlled in dependence of a sensor signal (of a sensor (see also above)).

For instance, movement of a person through a hallway may lead to adaptation of the spectral power distribution and/or radiant flux of one or more of the first device light and the second device light (or other adaptations, see also above). However, changing external conditions, such as time of the day, day of the year, light level, presence of clouds, rain, etc., hallway may lead to adaptation of the spectral power distribution and/or radiant flux of one or more of the first device light and the second device light (or other adaptations, see also above).

Hence, in embodiments, the control system may be configured to control a spectral power distribution of the lighting module light. Further, in embodiments, the control system may be configured to control one or more of the color rendering index (CRI), the correlated color temperature (CCT), and the color point of the first device light and/or the second device light (and hence, also the lighting module light). Hence, in specific embodiments, one or more of the first light generating device and the second light generating device have a controllable correlated color temperature of the respective device light; wherein the control system is configured to control the correlated color temperature of the respective device light in dependence of one or more of a user interface, a sensor signal (of a sensor), and a timer (or clock module), especially in embodiments in dependence of the sensor signal.

In embodiments, the lighting module may further comprise a third light generating device. Further, the light exit window may in embodiments comprise a third light emitting surface part. Especially, the third light emitting surface part may have a third surface area SA3 and a third perimeter (P3). Further, in embodiments, the third perimeter (P3) may touch the window perimeter (PO) or partly coincides with the window perimeter (PO). Yet further, the light exit window may have a surface area SAO, wherein SAO=SA1+SA2+SA3. This may specifically be the case in embodiments where the one or more light emitting surface parts do not comprise a boundary.

In other embodiments, the majority of the surface area of the light exit window may be comprised by the first light emitting surface part, the second light emitting surface part and the third light emitting surface part, especially 0.98*SA0 < SAI + SA2 + SA3, such as 0.95*SA0 < SAI + SA2 + SA3, more especially 0.9*SA0 < SAI + SA2 + SA3. Hence, in embodiments 0.9* SAO < SAI + SA2 + SA3 < SAO.

Furthermore, in embodiments, the third light generating device may be configured to generate third device light via the third light emitting surface part. Analogous to the second light emitting surface part, the third light emitting surface part in embodiments may have an ellipse-like cross-sectional shape. Embodiments of such (i.e., ellipse-like shape) have been discussed in further detail above. Alternatively, in embodiments, the third light emitting surface part may (also) have an arc-like cross-sectional shape.

Hence, in embodiments the third light emitting surface part is configured between the first light emitting surface part and the second light emitting surface part. In alternatively embodiments, the second light emitting surface part and the third light emitting surface part are separated by the first light emitting surface part.

Especially, in embodiments essentially all third device light escaping from the light generating system escapes via the third light emitting surface.

Hence, in specific embodiments the light generating system may be configured to generate system light comprising at least part of the first device light (emanating from the first light emitting surface), at least part of the second device light (emanating from the second light emitting surface), and at least part of the third device light (emanating from the third light emitting surface). Hence, in embodiments the first device light, the second device light, and the third device light may especially be generate simultaneously. Furthermore, in embodiments, the control system may be configured to control the one or more third light generating devices. Especially, the control system may be configured to control the light generating devices such that when the third light emitting surface part has an ellipse-like shape, in a first operational mode the third device light escaping via the third light emitting surface part has a spectral power distribution identical to a spectral power distribution of the first device light escaping via the first light emitting surface part. Additionally, or alternatively, the control system may operate in a second operational mode, wherein the second device light escaping via the second light emitting surface part has a spectral power distribution identical to a spectral power distribution of the first device light escaping via the first light emitting surface part, and the third device light escaping via the third light emitting surface part has a spectral power distribution identical to a spectral power distribution of the second device light escaping via the second light emitting surface part. In embodiments, when the third light emitting surface part has an ellipse-like shape, in a third operational mode the third device light escaping via the third light emitting surface part may have a spectral power distribution identical to a spectral power distribution of the first device light escaping via the first light emitting surface part. Yet further, in a fourth operational mode the third device light escaping via the third light emitting surface part may have a spectral power distribution identical to a spectral power distribution of the second device light escaping via the second light emitting surface part.

Hence in specific embodiments, the lighting module further comprises a third light generating device; wherein the light exit window comprises a third light emitting surface part, having a third surface area S A3 and a third perimeter (P3); wherein the third light generating device is configured to generate third device light via the third light emitting surface part; wherein the third light emitting surface part has (i) either an ellipse-like cross- sectional shape or (ii) an arc-like cross-sectional shape; the third perimeter (P3) touches the window perimeter (P0) or partly coincides with the window perimeter (P0); wherein the control system is configured to control the light generating devices such that: when the third light emitting surface part has an ellipse-like shape, in a first operational mode (a) the third device light escaping via the third light emitting surface part has a spectral power distribution identical to a spectral power distribution of the first device light escaping via the first light emitting surface part, and in a second operational mode the second device light escaping via the second light emitting surface part has a spectral power distribution identical to a spectral power distribution of the first device light escaping via the first light emitting surface part, and the third device light escaping via the third light emitting surface part has a spectral power distribution identical to a spectral power distribution of the second device light escaping via the second light emitting surface part; and when the third light emitting surface part has an ellipse-like shape, in a third operational mode (a) the third device light escaping via the third light emitting surface part has a spectral power distribution identical to a spectral power distribution of the first device light escaping via the first light emitting surface part, and in a fourth operational mode the third device light escaping via the third light emitting surface part has a spectral power distribution identical to a spectral power distribution of the second device light escaping via the second light emitting surface part.

As mentioned above, the light generating system may comprise the first light chamber and the second light chamber. In further embodiments, the light generating system may comprise a third light chamber. Especially, the third light chamber may be an enclosed space, wherein one of the walls may in embodiments comprise the third light emitting surface part. Further, in embodiments, the other walls of the third light chamber may be reflective. In embodiments, at least part of the third light generating device may be comprised by the third light chamber. Hence, third device light (generated by the third light generating device) may be outcoupled from the third light chamber via the third light emitting surface part. Further, in embodiments, the third light chamber may not be in optical communication with either the first light chamber or the second light chamber.

Especially, the third light chamber, the first light chamber, and the second light chamber are not configured in mutual optical communication.

Alternatively, in embodiments, the light generating device may comprise a third light guide (in addition to the first light guide and the second light guide). Especially, the third light guide may comprise the third light emitting surface part. In embodiments, the third light guide may be configured in a light receiving relationship with the third light generating device. Further, in embodiments, the third light guide may comprise a third light emitting light guide surface from which during operation of the third light generating device, third device light emanates. Especially, the third light emitting surface part may be configured in a light receiving relationship with the third light emitting light guide surface or may comprise the third light emitting light guide surface. In embodiments, the one or more light guides may not be configured in mutual optical communication. Especially, the first light guide, the second light guide and the third light guide may be not in mutual optical communication.

Especially, the third light guide, the first light guide, and the second light guide are not configured in mutual optical communication. Further, in such embodiments, the third light generating devices may be configured outside the third light chamber and may provide third device light to the third light guide. Embodiments, such as this may provide flexibility in the physical location at which the first (or second, or third) light generating devices may be configured in relation to the light exit window. As mentioned before, in embodiments, the light guides may be separated by a specular reflector. However, in other embodiments, the light guides may (also) be separated by a diffusive reflector.

Further, in embodiments, a variation in a luminous exitance of the first device light over the first light emitting surface part or a variation in a luminous exitance of the second device light over the second light emitting surface part may be less than 5% from a respective average luminous exitance. Yet further, in embodiments, a variation in a luminous exitance of the second device light over the second light emitting surface part or a variation in a luminous exitance of the third device light over the third light emitting surface part may be less than 5% from a respective average luminous exitance (see also below). Hence, in embodiments one or more of the following may apply: (i) a variation in a luminous exitance of the first device light over the first light emitting surface part is less than 5% from an r average luminous exitance over the first light emitting surface, and (ii) a variation in a luminous exitance of the second device light over the second light emitting surface part is less than 5% from an average luminous exitance over the second light emitting surface part. If applicable, also additionally, or alternatively, the following may apply: (iii) ) a variation in a luminous exitance of the third device light over the third light emitting surface part is less than 5% from an average luminous exitance over the third light emitting surface part.

Herein, controlling the first device light may especially refer to controlling one or more of a color point and radiant flux of the first device light. Likewise, controlling the second device light may especially refer to controlling one or more of a color point and radiant flux of the second device light. Yet, likewise controlling the third device light may especially refer to controlling one or more of a color point and radiant flux of the third device light

In yet a further aspect, the invention also provides a lamp or a luminaire comprising the light generating system as defined herein. The luminaire may further comprise a housing, optical elements, louvres, etc. etc... The lamp or luminaire may further comprise a housing enclosing the light generating system. The lamp or luminaire may comprise a light window in the housing or a housing opening, through which the system light may escape from the housing. In yet a further aspect, the invention also provides a projection device comprising the light generating system as defined herein. Especially, a projection device or “projector” or “image projector” may be an optical device that projects an image (or moving images) onto a surface, such as e.g. a projection screen. The projection device may include one or more light generating systems such as described herein. Hence, in an aspect the invention also provides a light generating device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system as defined herein. The light generating device may comprise a housing or a carrier, configured to house or support, one or more elements of the light generating system.

In a further aspect, the invention may provide an indoor space. The space may in embodiments comprise one or more of a wall, slanted wall, room divider, roof, slanted roof and ceiling. Especially the indoor space may further comprise the light generating system suspended from the roof, slanted roof or ceiling, or wall. In other embodiments, the light generating system may be physically attached to the ceiling or wall by means of screws or fasteners. Hence, in this way, the light generating system may be functionally coupled to the ceiling or wall. Further, in embodiments, the light generating system may illuminate the indoor space with lighting module, especially an artificial skylight light.

The term “indoor space” or “space” may for instance relate to a (part ol) hospitality area, such as a restaurant, a hotel, a clinic, or a hospital, etc.. The term “space” may also relate to (a part ol) an office, a department store, a warehouse, a cinema, a church, a theatre, a library, etc. However, the term “space” may also relate to (a part of) a working space in a vehicle, such as a cabin of a truck, a cabin of an airplane, a cabin of a vessel (ship), a cabin of a car, a cabin of a crane, a cabin of an engineering vehicle like a tractor, a cabin of a train carriage, etc.. The term “space” may also relate to (a part of) a working space, such as an office, a (production) plant, a power plant (like a nuclear power plant, a gas power plant, a coal power plant, etc.), etc. For instance, the term “space” may also relate to a control room, a security room, etc.. Especially, the term “space” may herein refer to an indoor space. In yet other embodiments, the term “space” may also relate to a toilet room or bathroom. In yet other embodiments, the term “space” may also relate to an elevator. In embodiments, the term “space” may also refer to a conference room, a school room, an indoor hallway, an indoor corridor, an indoor space in an elderly home, an indoor space in a nursing home, etc. In embodiments, the term “space” may refer to an indoor sport space, like a gym, a gymnastics hall, in indoor ball sport space, a ballet room, a swimming pool, a changing room, etc. In embodiments, the term “space” may refer to an (indoor) bar, an (indoor) disco, etc. Further, in embodiments, the indoor space may comprise the control system and optionally a sensor. Embodiments of such have been described further above.

BRIEF DESCRIPTION OF THE DRAWINGS

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

Figs, la-lc schematically depict different views of the light generating system 1000.

Figs. 2a-2b schematically depict an embodiment of the light generating system 1000 comprising the first light guide 1310 and the second light guide 1320.

Figs. 3a-3b depict an embodiment of the light generating system 1000 comprising a third light emitting surface part 1130 and third light generating devices 130.

Figs. 4a-4b depict an alternative embodiment of the light generating system 1000 comprising a third light emitting surface part 1130 and third light generating devices 130.

Figs. 5a-5b schematically depict embodiments of the lighting device 1200 comprising the light generating system 1000. The schematic drawings are not necessarily to scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Fig. 1 schematically depicts different views of the light generating system 1000. Fig. la shows an isometric view, Fig. lb atop view and Fig. 1c a cross-sectional view of the light generating system, respectively.

In embodiments, the invention provides a light generating system 1000 comprising a lighting module 1500. Especially, the lighting module 1500 may comprise a first light generating device 110, and a second light generating device 120 (shown in Fig. 1c). As mentioned above, in embodiments, the first light generating device 110 may generate first device light 111 and the second light generating device 120 may generate second device light 1221, which may escape via the light exit window 1100. In embodiments, the light generating system 1000 may be configured to provide lighting module light 1501 (comprising the first device light 111 and second device light 121) via the light exit window 1100. The light generated by light generating system 1000 may especially be referred to as the system light 1001. In embodiments, the system light 1001 may comprise the lighting module light 1501.

The surface geometry of the light exit window 1100 can be observed in the top view of the light generating system 1000 (shown in Fig. lb). In embodiments, the light exit window 1100 may have a window perimeter PO. In the embodiment depicted, the lighting module 1500 has a circular shape with a perimeter PO. Further, in embodiments, the lighting module 1500 may comprise (i) a first light emitting surface part 1110 having a first perimeter Pl, and a second light emitting surface part 1120 having a second perimeter P2. Especially, the second light emitting surface part 1120 may have an ellipse-like cross-sectional shape. Note that the shape is ellipse like, meaning, in embodiments, the shape may be the same as the overlap region between two intersecting circles. Hence, in such a shape, a major and minor axis may be defined, and hence, the shape may be ellipse-like in that sense. Furthermore, in such a shape, the ellipse-like cross-sectional shape may especially have sharp edges. Especially, the ellipse-like shape may comprise two pointed ends (as depicted in Fig. lb) i.e. the shape may not be oval (or ellipsoidal) but rather the shape may have sharp edges (such as obtained from the intersection of two circles).

The ellipse-like cross-sectional shape may have a first part of its perimeter P2 touching the window perimeter P0 or partly coinciding with the window perimeter PO and a second part of its perimeter P2 touching the first perimeter Pl or partly coinciding with the first perimeter Pl of the first light emitting surface part.

The interior of the light generating system 1000 can be observed in the cross- sectional view of the light generating system 1000 (shown in Fig. 1c). In embodiments, the first light generating device 110 may be configured to generate first device light 111 via the first light emitting surface part 1110. Further, in embodiments, the second light generating device 120 may be configured to generate second device light 121 via the second light emitting surface part 1120. As mentioned above, in embodiments, the lighting module 1501 may comprise one or more of the first device light 111 and the second device light 121.

In embodiments, the first device light 111 may be white light having a first correlated color temperature CCT1 of at maximum 8000 K. A lower CCT value (such as lower than 5000 K) may especially relate to warmer light for e.g. sunlight. In embodiments, the second device light 121 may be (i) blue light or (ii) white light having a second correlated color temperature CCT2 of at least 5000 K. Larger CCT values in embodiments may especially relate to cooler light such as skylight. As mentioned before, skylight may especially be blue light such as the color of the sky during a sunny day. Yet further, in embodiments the first device light 111 and the second device light 121 may both be white light. In such embodiments, when both the first device light 111 and the second device light 121 are white light, then CCT2-CCTl>500 K.

In embodiments, the first light emitting surface part 1110 and the second light emitting surface part 1120 may be configured such that they share at least a part of an edge or perimeter. Hence, in embodiments, both the first perimeter Pl and the second perimeter P2 may touch the window perimeter P0 or partly coincide with the window perimeter P0, as can be seen in Fig. lb.

As mentioned above, in embodiments, the second light emitting surface may especially be ellipse-like (see Fig. la and lb). In further embodiments, the second light emitting surface part 1120 may have a lens-like cross-sectional shape. Lens-like shape may especially refer to a shape defined by the two intersecting arcs, especially the shape may be convex (i.e. the intersecting arcs bow outwards). In embodiments, the light exit window 1100 may have a circular cross-sectional shape. Further, in embodiments the light exit window 1100 may have a plane of symmetry PS (indicated in Fig. lb) intersecting both the first light emitting surface part 1110 and the second light emitting surface part 1120.

In embodiments, the optical axis O may be defined in the center of and perpendicular to the light exit window 1100.

Also depicted in Fig. lb are the surface areas SAI, SA2, and SA0. In embodiments, the first light emitting surface part 1110 may have a first surface area SAI . Especially, the second light emitting surface part 1120 may have a second surface area SA2. More especially, SA2<SA1. Further, in embodiments, the light exit window 1100 may have a surface area SA0. Especially, SAO=SA1+SA2.

Analogously, in embodiments, L2<O.4*L1. Here, LI may refer to the longest dimension of the first light emitting surface part. In the embodiment depicted in the figure, the first light emitting surface part may have the longest dimension LI (equal to the diameter of the circular light exit window 1100). Further, in embodiments, L2 may be the longest dimension of the second light emitting surface part 1120. Hence, in embodiments, L2 may be the major axis of the ellipse-like shape, see Fig. lb.

In embodiments, CCT1 and CCT2 may defined such that 2700 K < CCT1 <6500 K, and especially CCT2 > 6500 K. Especially, 6500 K < CCT2 < 20000 K. Furthermore, in embodiments, CCT2-CCT1> 2000 K.

Fig. 1c depicts a cross-sectional view, thus providing a view of the components configured inside the embodiment of the light generating system 1000. In embodiments, the light generating system 1000 may comprise (i) a first light chamber 1210 comprising the first light emitting surface part 1110 and enclosing at least part of the first light generating device 110. Similarly, in embodiments, the light generating system may comprise a second light chamber 1220 comprising the second light emitting surface part 1120 and enclosing at least part of the second light generating device 120. Yet further, in embodiments, the light chambers 1210,1220 may not be configured in mutual optical communication. In embodiments, the light chambers 1210,1220 may be separated by a (diffuse) reflector.

In embodiments, the light exit window 1100 may comprise an optical diffuser 410. Especially, the optical diffuser 410 may comprise the first light emitting surface part 1110 and second light emitting surface part 1120. In embodiments, the optical diffuser 410 configured over the first light chamber 1210 may not be optical communication with the optical diffuser 410 configured over the second light chamber 1220. In embodiments, they may be separated by the (diffuse) reflector.

In embodiments, the first light chamber 1210 may comprise at least part of a plurality of first light generating devices 110. In further embodiments, the second light chamber 1220 may comprise at least part of a plurality of second light generating devices 120.

In embodiments, the light generating system 1000 may further comprise a sensor 310 (depicted in Fig. 1c). The sensor 310 may be external of the housing or may be comprised by the housing. Especially, the sensor 310 may be configured (i) to sense presence and/or movement of a human, and (ii) to generate a related sensor signal. Further, in embodiments, the control system 300 may be configured to (individually) control the first light generating device 110 and the second light generating device 120 in dependence of an input signal of the sensor signal (of the sensor 310).

The height of the module 1500, indicated with reference Hl, may e.g. be selected from the range of 1-100 mm, such as for instance in the range of 5-20 mm.

Fig. 2 schematically depicts an embodiment of the light generating system 1000 comprising the first light guide 1310 and the second light guide 1320. Fig. 2a shows an isometric view and Fig. 2b shows a top view of the light generating system 1000.

In the embodiment depicted, the light generating system 1000 may comprise a first light guide 1310 and a second light guide 1320. In embodiments, the first light guide 1310 may be configured in a light receiving relationship with the first light generating device 110. Especially, the first light guide 1310 may comprise a first light emitting light guide surface 1311 from which during operation of the first light generating device 110 first device light 111 emanates. More especially, the first light emitting surface part 1110 may be configured in a light receiving relationship with the first light emitting light guide surface 1311 or may comprise the first light emitting light guide surface 1311. That is, the first light generating device 110 may shine first device light 111 onto the first light guide 1310 which may then be outcoupled via the light exit window 1100.

Similarly, in embodiments, the second light guide 1320 may be configured in a light receiving relationship with the second light generating device 120. Especially, the second light guide 1320 may comprise a second light emitting light guide surface 1321 from which during operation of the second light generating device 120 second device light 121 emanates. More especially, the second light emitting surface part 1120 may be configured in a light receiving relationship with the second light emitting light guide surface 1321 or may comprise the second light emitting light guide surface 1321. That is, the second light generating device 120 may shine second device light 121 onto the second light guide 1320 which may then be outcoupled via the light exit window 1100.

Further, in embodiments, the light guides 1310,1320 may not be configured in mutual optical communication. Note that in the embodiment depicted, the light generating device 1000 comprising the first light guide 1310 and the second light guide 1320 both may be illuminated by the one or more first light generating devices 110 and the one or more second light generating devices 120. Especially, the first light generating devices 110 and the second light generating devices 120 may be configured outside the lighting module 1500. Hence, the first light generating devices 110 and the second light generating devices 120 may illuminate the first light guide 1310 and the second light guide 1320, respectively from the outside. Further, in embodiments, the light guides 1310,1320 may be separated by a (specular) reflector. Hence, preventing optical communication between the first light guide 1310 and the second light guide 1320.

In the embodiment depicted, the first light guide 1310 and the second light guide 1320 may be separated, that is, they are not in physical contact. This can be observed in both Fig. 2a and 2b, however, in the embodiment depicted, both the first perimeter Pl and the second perimeter P2 may touch the window perimeter PO or partly coincide with the window perimeter PO.

As (also) indicated in Fig. 1, in the embodiment depicted, the light generating system may further comprise a control system 300 and a sensor 310. In embodiments, the sensor 310 may be configured (i) to sense presence and/or movement of a human, and (ii) to generate a related sensor signal. Further, in embodiments, the control system 300 may be configured to (individually) control the first light generating device 110 and the second light generating device 120 in dependence of an input signal of the sensor signal (of the sensor 310).

Further, in embodiments, one or more of the first light generating device 110 and the second light generating device 120 may have a controllable spectral power distribution of the respective device light 111,121. Especially, the control system 300 may be configured to control the spectral power distribution of the respective device light 111, 121 in dependence of the sensor signal.

In embodiments, the one or more of the first light generating device 110 and the second light generating device 120 may have a controllable correlated color temperature of the respective device light 111,121. Especially, the control system 300 may be configured to control the correlated color temperature of the respective device light 111,121 in dependence of the sensor signal.

Fig. 3 depicts an embodiment of the light generating system 1000 comprising a third light emitting surface part 1130 and third light generating devices 130. Fig. 3a and 3b show a cross-sectional view and top view of the said light generating system 1000.

Fig. 3a depicts a cross-sectional view, thus providing a view of the components configured inside the embodiment of the light generating system 1000. In embodiments, the light generating system 1000 may comprise (i) a first light chamber 1210 comprising the first light emitting surface part 1110 and enclosing at least part of the first light generating device 110. Similarly, in embodiments, the light generating system 1000 may comprise a second light chamber 1220 comprising the second light emitting surface part 1120 and enclosing at least part of the second light generating device 120. Further, in embodiments, the light generating system 1000 may comprise a third light chamber 1230 comprising the third light emitting surface part 1130 and enclosing at least part of the third light generating device 130.

Yet further, in embodiments, the light chambers 1210, 1220 and 1230 may not be configured in mutual optical communication. However, the optical diffuser 410 as shown in Fig. 3a may be a single diffuser and hence, the parts of the optical diffuser 410 configured above the first light chamber 1210, the second light chamber 1220 and the third light chamber 1230 may be in mutual optical communication. In embodiments, the optical diffuser 410 may comprise the first light emitting surface part 1110, the second light emitting surface part 1120 and the third light emitting surface part 1130. In embodiments, the third light emitting surface part 1130 may have a third surface area SA3 and a third perimeter P3. In embodiments, the third light generating device

130 may be configured to generate third device light 131 (shown in Fig. 3a) via the third light emitting surface part 1130. Especially, the third light emitting surface part 1130 may have an ellipse-like cross-sectional shape (as depicted in Fig. 3b). Further, in embodiments, the third perimeter P3 may touch the window perimeter PO or partly coincide with the window perimeter PO.

In embodiments, the control system 300 may be configured to control the light generating devices 110,120,130. Especially, when the third light emitting surface part 1130 has an ellipse-like shape, in a first operational mode (a) the third device light 131 may escape via the third light emitting surface part 1130. Especially, the third device light 131 may have a spectral power distribution identical to a spectral power distribution of the first device light 111 escaping via the first light emitting surface part 1110.

Further, in embodiments, in a second operational mode the second device light 121 escaping via the second light emitting surface part 1120 may have a spectral power distribution identical to a spectral power distribution of the first device light 111 escaping via the first light emitting surface part 1110. Yet further, in embodiments, the third device light

131 escaping via the third light emitting surface part 1130 may have a spectral power distribution identical to a spectral power distribution of the second device light 121 escaping via the second light emitting surface part 1120.

In embodiments, when the third light emitting surface part 1130 may have an ellipse-like shape, in a third operational mode (a) the third device light 131 escaping via the third light emitting surface part 1130 may have a spectral power distribution identical to a spectral power distribution of the first device light 111 escaping via the first light emitting surface part 1110. Furthermore, in embodiments, in the fourth operational mode the third device light 131 escaping via the third light emitting surface part 1130 may have a spectral power distribution identical to a spectral power distribution of the second device light 121 escaping via the second light emitting surface part 1120.

Embodiments of the light generating system 1000 comprising three light emitting surface parts, may comprise the light exit window 1100 having a surface area SA0. Especially, wherein SAO=SA1+SA2+SA3.

In embodiments, there may be a variation in a luminous exitance of the first device light 111 over the first light emitting surface part 1110. Alternatively, in embodiments, there may be a variation in a luminous exitance of the second device light 121 over the second light emitting surface part 1120 is less than 5 from a respective average luminous exitance.

Further, as indicated above, the light generating system 1000 may comprise a control system 300 to (individually) control the first light generating device 110, the second light generating device 120 and the third light generating device 130. Especially, the light generating system 1000 may comprise a sensor 310, wherein the control system 300 may control the light generating system 1000 in dependence of the sensor signal.

Fig. 4 depicts an alternative embodiment of the light generating system 1000 comprising a third light emitting surface part 1130 and third light generating devices 130. Fig. 4a depicts atop view and Fig. 4b shows a cross-section of an embodiment of the light generating system 1000. In embodiments, the third light emitting surface part 1130 may (also) have an arc-like cross-sectional shape (as shown in Fig. 4a).

In embodiments, the light generating system 1000 may comprise a first light emitting surface part 1110, the second light emitting surface part 1120 and the third light emitting surface part 1130 which may have perimeters Pl, P2 and P3, respectively. Especially, at least a part of the perimeters Pl, P2 and P3 may be coincident with the perimeter P0 of the light emitting surface 1100. Further, the first light emitting surface part 1110, the second light emitting surface part 1120, and the third light emitting surface part 1130 may especially have surface areas SAI, SA2, and SA3, respectively. Especially, SA0 = SA1+SA2 +SA3.

Further as depicted in the cross-section (see Fig. 4b), in embodiments, the light generating system 1000 may comprise the first light chamber 1210, the second light chamber 1220 and the third light chamber 1230, wherein the said light chambers are not in mutual optical communication.

In embodiments, the first light chamber 1210, the second light chamber 1220 and the third light chamber 1230, may (each) enclose one or more first light generating devices 110, second light generating devices 120 and third light generating devices 130, respectively. Especially, the first light generating device 110, the second light generating device 120 and the third light generating device 130 may generate first device light 111, the second device light 121 and the third device light, respectively 131. Especially, the system light 1001 may comprise the first device light 111, the second device light 121 and third device light 131.

Referring to Figs. 3b and 4a, in embodiments the third light emitting surface part is configured between the first light emitting surface part and the second light emitting surface part, and in alternatively embodiments, the second light emitting surface part and the third light emitting surface part are separated by the first light emitting surface part.

Other aspects defined in relation to other embodiments described above may also apply to the present invention. These features are not repeated for the sake of brevity. However, these features (also) do not limit the scope of the features described herein.

Fig. 5a schematically depicts an embodiment of the lighting device 1200 comprising the light generating system 1000. The schematic drawings are not necessarily to scale. In embodiments, the invention may provide an indoor space 1300 comprising a ceiling 1310 and the light generating system 1000. Especially, the lighting module 1500 may be functionally coupled to the ceiling 1310. Furthermore, in embodiments, the light generating system may further comprise the control system 300 and sensor 310. Hence, Fig. 5a schematically depicts embodiments of a lighting device 1200 selected from the group of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system 1000 as described herein. In embodiments, such lighting device may be a lamp 1, a luminaire 2, a projector device 3, a disinfection device, or an optical wireless communication device. Lighting device light escaping from the lighting device 1200 is indicated with reference 1201. Lighting device light 1201 may essentially consist of system light 1001, and may in specific embodiments thus be system light 1001. In embodiments, the light generating device 1200 may be configured provide system light 1001 on one or more surfaces in a room 1300. Especially, the light generating system 1000 may illuminate the walls 1307, or the floor 1305, or the ceiling 1310 in a room 1300. Reference 301 indicates a user interface which may be functionally coupled with the control system 300 comprised by or functionally coupled to the light generating system 1000.

Fig. 5b schematically depicts a hallway. The hallway may comprise windows. Optionally, the hallway may comprise the lighting module functionally coupled to a (side) wall 1307 (not depicted). This may also mimic a window. Here, a plurality of modules 1500 are depicted, which are functionally coupled to the ceiling 1310. Here, by way of example three modules 1500 are depicted, but also a single module 1500, two modules 1500, or more than three modules 1500 may be available. Only by way of example, the modules have different shapes.

The term “plurality” refers to two or more.

The terms “substantially” or “essentially” herein, and similar terms, will be understood by the person skilled in the art. The terms “substantially” or “essentially” may also include embodiments with “entirely”, “completely”, “all”, etc. Hence, in embodiments the adjective substantially or essentially may also be removed. Where applicable, the term “substantially” or the term “essentially” may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%.

The term “comprise” also includes embodiments wherein the term “comprises” means “consists of’.

The term “and/or” especially relates to one or more of the items mentioned before and after “and/or”. For instance, a phrase “item 1 and/or item 2” and similar phrases may relate to one or more of item 1 and item 2. The term "comprising" may in an embodiment refer to "consisting of but may in another embodiment also refer to "containing at least the defined species and optionally one or more other species".

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

The devices, apparatus, or systems may herein amongst others be described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation, or devices, apparatus, or systems in operation.

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

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

Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

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

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

The invention also provides a control system that may control the device, apparatus, or system, or that may execute the herein described method or process. Yet further, the invention also provides a computer program product, when running on a computer which is functionally coupled to or comprised by the device, apparatus, or system, controls one or more controllable elements of such device, apparatus, or system.

The invention further applies to a device, apparatus, or system comprising one or more of the characterizing features described in the description and/or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and/or shown in the attached drawings.

The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

Claims

CLAIMS:

1. A light generating system (1000) comprising a lighting module (1500), wherein the lighting module (1500) comprises a skylight module; wherein the lighting module (1500) comprises a first light generating device (110), a second light generating device (120), and a light exit window (1100); wherein the light generating system (1000) is configured to provide lighting module light (1501) via the light exit window (1100); wherein: the light exit window (1100) has a window perimeter (PO) and comprises: (i) a first light emitting surface part (1110) having a first perimeter (Pl), and (ii) a second light emitting surface part (1120) having a second perimeter (P2); the second light emitting surface part (1120) has an ellipse-like cross-sectional shape; the first light generating device (110) is configured to generate first device light (111) via the first light emitting surface part (1110); the second light generating device (120) configured to generate second device light (121) via the second light emitting surface part (1120); the first device light (111) is white light having a first correlated color temperature CCT1 of at maximum 8000 K; the second device light (121) is (i) blue light or (ii) white light having a second correlated color temperature CCT2 of at least 5000 K; wherein when both the first device light (111) and the second device light (121) are white light, then CCT2-CCTl>500 K; and both the first perimeter (Pl) and the second perimeter (P2) touch the window perimeter (P0) or partly coincide with the window perimeter (PO).

2. The light generating system (1000) according to claim 1, wherein the ellipselike shape comprises two pointed ends.

3. The light generating system (1000) according to any one of the preceding claims, wherein the second light emitting surface part (1120) has lens-like cross-sectional shape.

4. The light generating system (1000) according to any one of the preceding claims, wherein the light exit window (1100) has a circular cross-sectional shape; wherein the light exit window (1100) has a plane of symmetry (PS) intersecting both the first light emitting surface part (1110) and the second light emitting surface part (1120).

5. The light generating system (1000) according to any one of the preceding claims, comprising (i) a first light chamber (1210), comprising the first light emitting surface part (1110) and enclosing at least part of the first light generating device (110), and (ii) a second light chamber (1220), comprising the second light emitting surface part (1120) and enclosing at least part of the second light generating device (120); wherein the light chambers (1210,1220) are not configured in mutual optical communication.

6. The light generating system (1000) according to claim 5, wherein the light exit window (1100) comprises an optical diffuser (410), wherein the optical diffuser (410) comprises the first light emitting surface part (1110) and second light emitting surface part (1120).

7. The light generating system (1000) according to any one of the preceding claims 1-4, wherein the light generating system (1000) comprises a first light guide (1310) and a second light guide (1320), wherein: the first light guide (1310) is configured in a light receiving relationship with the first light generating device (110); wherein the first light guide (1310) comprises a first light emitting light guide surface (1311) from which during operation of the first light generating device (110) first device light (111) emanates; wherein the first light emitting surface part (1110) is configured in a light receiving relationship with the first light emitting light guide surface (1311) or comprises the first light emitting light guide surface (1311); the second light guide (1320) is configured in a light receiving relationship with the second light generating device (120); wherein the second light guide (1320) comprises a second light emitting light guide surface (1321) from which during operation of the second light generating device (120) second device light (121) emanates; wherein the second light emitting surface part (1120) is configured in a light receiving relationship with the second light emitting light guide surface (1321) or comprises the second light emitting light guide surface (1321); and the light guides (1310,1320) are not configured in mutual optical communication.

8. The light generating system (1000) according to any one of the preceding claims, further comprising a control system (300), wherein the control system (300) is configured to individually control the first light generating device (110) and the second light generating device 120) in dependence of one or more of an input signal of a user interface (301), a sensor signal of a sensor (310), and a timer.

9. The light generating system (1000) according to claim 8, wherein the light generating system (1000) further comprises a sensor (310), wherein the sensor (310) is configured (i) to sense presence and/or movement of a human, and (ii) to generate a related sensor signal, and wherein the control system (300) is configured to individually control the first light generating device (110) and the second light generating device 120).

10. The light generating system (1000) according to claims 8-9, wherein one or more of the first light generating device (110) and the second light generating device (120) have a controllable spectral power distribution of the respective device light (111,121); wherein the control system (300) is configured to control the spectral power distribution of the respective device light (111,121).

11. The light generating system (1000) according to claims 8-9 or claim 10, wherein one or more of the first light generating device (110) and the second light generating device (120) have a controllable correlated color temperature of the respective device light

(111,121); wherein the control system (300) is configured to control the correlated color temperature of the respective device light (111,121).

12. The light generating system (1000) according to any one of the preceding claims 8-11, wherein the lighting module (1500) further comprises a third light generating device (130); wherein: the light exit window (1100) comprises a third light emitting surface part

(1130), having a third surface area SA3 and a third perimeter (P3); the third light generating device (130) is configured to generate third device light (131) via the third light emitting surface part (1130); the third light emitting surface part (1130) has (i) either an ellipse-like cross- sectional shape or (ii) an arc-like cross-sectional shape; the third perimeter (P3) touches or partly coincides with the window perimeter (P0); and the control system (300) is configured to control the light generating devices (110,120,130) such that when: (I) the third light emitting surface part (1130) has an ellipselike shape, in a first operational mode (a) the third device light (131) escaping via the third light emitting surface part (1130) has a spectral power distribution identical to a spectral power distribution of the first device light (111) escaping via the first light emitting surface part (1110), and in a second operational mode the second device light (121) escaping via the second light emitting surface part (1120) has a spectral power distribution identical to a spectral power distribution of the first device light (111) escaping via the first light emitting surface part (1110), and the third device light (131) escaping via the third light emitting surface part (1130) has a spectral power distribution identical to a spectral power distribution of the second device light (121) escaping via the second light emitting surface part (1120); and (II) the third light emitting surface part (1130) has an ellipse-like shape, in a third operational mode (a) the third device light (131) escaping via the third light emitting surface part (1130) has a spectral power distribution identical to a spectral power distribution of the first device light (111) escaping via the first light emitting surface part (1110), and in a fourth operational mode the third device light (131) escaping via the third light emitting surface part (1130) has a spectral power distribution identical to a spectral power distribution of the second device light (121) escaping via the second light emitting surface part (1120);

13. The light generating system (1000) according to any one of the preceding claims, wherein one or more of the following applies: (i) a variation in a luminous exitance of the first device light (111) over the first light emitting surface part (1110) is less than 5% from a respective average luminous exitance, and (ii) a variation in a luminous exitance of the second device light (121) over the second light emitting surface part (1120) is less than 5% from a respective average luminous exitance.

14. An indoor space (1300) comprising a ceiling (1310) and the light generating system (1000) according to any one of the preceding claims, wherein the lighting module (1500) is functionally coupled to the ceiling (1310).

15. The indoor space (1300) according to claim 14, further comprising a control system (300), wherein the control system (300) is configured to individually control the lighting module (1500) in dependence of one or more of an input signal of a user interface, a sensor signal of a sensor (310), and a timer.