EP4652407A1

EP4652407A1 - A linear light emitting device providing adjustable beam profile

Info

Publication number: EP4652407A1
Application number: EP24700150.6A
Authority: EP
Inventors: Marcus Theodorus Maria LAMBOOIJ; René BELTMAN; Barry Mos; Hendrikus Johan Adrie DE VRIES
Original assignee: Signify Holding BV
Current assignee: Signify Holding BV
Priority date: 2023-01-19
Filing date: 2024-01-10
Publication date: 2025-11-26
Also published as: WO2024153511A1; CN120513367A

Abstract

A light emitting device (1) adapted for emitting through a light exit window (22) device light (24) having an adjustable beam profile. Said light emitting device (1) comprises an elongated reflector (2) with a reflector opening (23), the reflector is curved around a central line (CL) and delimits a cavity (3). Said reflector (2) comprises mutually opposite first and second edges (4,5) on either side of the central line (CL) and bordering said reflector opening (23). Rims (10,10a,10b), comprising an inner rim surface (11,11a,11b) facing said cavity (3), are connected to respectively said edges (4,5) at said reflector opening (23), extend along the central line (CL), and border said light exit window (22). Said light emitting device (1) further comprises a peripheral (12) and a central LED light source (13), both arranged on said inner surface (11,11a,11b) and facing away from the light exit window (22). Said peripheral LED light source (12) being arranged to emit first light (14) towards a peripheral reflector portion (9) of the reflector (2), said central LED light source (13) being arranged to emit second light (15) towards a central reflector portion (8) of the reflector (2). Said light emitting device (1) further comprises a divider (16) between said peripheral and said central LED light sources (12,13) such that the second light (15) is screened from directly impinging on the peripheral reflector portion (9).

Description

A LINEAR LIGHT EMITTING DEVICE PROVIDING ADJUSTABLE BEAM PROFILE

FIELD OF THE INVENTION

The invention relates to a light emitting device adapted for emitting device light having an adjustable beam profile.

BACKGROUND OF THE INVENTION

Luminaires with downwards facing LEDs are widely known. Recently, another archetype of luminaires has been gaining popularity, namely luminaires having LEDs facing upwards, wherein the radiation is emitted towards a cavity that in turn provides beam shape. The cavity is often formed by a linear white non-specular back reflector resulting in an efficient and attractive-looking glare-free luminaire. With a purely non-specular white reflector it is close to impossible to do any significant beam shaping and as a result all luminaires based on this concept currently on the market produce a close to Lambertian light distribution.

It is thus desired to provide a light emitting device, in particular a linear light emitting device, comprising upwardly directed radiation sources and having improved beam shaping.

SUMMARY OF THE INVENTION

The present invention provides such a light emitting device and is set out in the appended set of claims. The light emitting device according to the present invention is adapted for emitting device light having an adjustable beam profile. The beam profile provided by light emitting device of the present invention may e.g. have a shape of a batwing, may be Lambertian or droplet-like. Preferably, the device light has a batwing shaped beam profile. The light emitting device of the present invention has a longitudinal extension and a transverse extension being substantially perpendicular to the longitudinal extension. In particular, the light emitting device according to the present invention may be elongated. The term “elongated” in the context of the present invention means that the longitudinal extension of the light emitting device is significantly greater than the transverse extension of the light emitting device, e.g. at least two times greater. Throughout the description, directions will be addressed as “downward”, “upward”. In the context of the present invention, the term “downward direction” is to be understood as a direction aligned with a vector of gravitational acceleration. The vector of gravitational acceleration may be understood as being a gravitational acceleration vector of a celestial body, e.g. the Earth, on which the light emitting device is arranged or located. It is intuitively understood that the term “upward direction” is the direction being opposite to the downward direction, i.e. a direction arranged 180° from the downward direction.

The light emitting device according to the present invention comprises a reflector with a reflector opening and a cross sectional extension (T). The reflector further comprises a reflector wall having a visible light reflective inner reflector surface. The (wall of the) reflector is curved around a central line (CL), delimits a (linear) cavity and comprises a first edge and a second edge. The first and/or the second edges are mutually opposite on either side of the central line and may be arranged substantially parallel to the longitudinal extension of the light emitting device. The first and the second edges are spaced apart by the transverse extension of the reflector and border the reflector opening. In particular, the first and the second edges may be substantially parallel to each other. The reflector may have a longitudinal extension and a transverse extension being substantially perpendicular to the longitudinal extension, wherein the longitudinal extension of the reflector is substantially parallel to the longitudinal extension of the light emitting device. The longitudinal extension of the reflector may be equal to the longitudinal extension of the light emitting device.

The cross-sectional shape of the reflector may be square, rectangular, triangular, circular, or the like. In particular, the reflector in its transverse extension may comprise a central portion and a peripheral portion. The reflector may be curved, wherein the central portion and the peripheral reflector portion have a respective concavely curvature towards the cavity. The curvature of the peripheral reflector portion may have a smaller (average) radius than the (average) radius of the curvature of the central reflector portion, i.e. the curvature of the peripheral reflector portion is stronger than the curvature of the central reflector portion. The peripheral portion of the reflector may be substantially invisible to the observer, thus offering the advantage of aesthetically appealing light emitting device combined with improved performance in terms of light distribution.

The inner surface of the central portion may be non-specular reflective. In particular, the inner surface of the central portion of the linear reflector may be white. The inner surface of the peripheral portion of the reflector may be at least partially specular reflective. In particular, the reflector may have a parabolic cross-section. The white reflector can be made of any material that is close to non-specular and preferably highly reflective for efficiency. The non-specular reflector offers the advantage of improved light distribution, such that the device light emitted by the light emitting device is perceived as coming from the entire linear cavity hence being very comfortable. In an embodiment, the specular reflective surface is made from a metal. The metal may be or comprise aluminum, silver or combinations thereof. For example, the reflector may be made of folded metal. The metal may also be applied by means of CVD or PVD on another surface or carrier such as a polymer or a metal layer.

The peripheral reflector portion may be in the form of small reflector parts that can be specular or semi-specular, thus reflecting light in a (possibly quite large) cone of directions around the specular direction. The more specular the peripheral reflector portion is, the more control of beam shaping is possible. On the other hand, a lower degree of specularity of the peripheral reflector portion provides less glare of the light emitting device under large angles, i.e. in the direction being substantially parallel with the transverse extension of the light emitting device, and also in the longitudinal direction.

The light distribution of the central reflector portion and the peripheral reflector portions may be selected such that one portion may create a wide distribution to improve spatial brightness while the other portions can provide a narrower distribution to improve task illumination. In such an embodiment, the light emitting device may comprise a control unit for controlling the light distribution provided by the different portions of the reflector. For instance, the task illumination may be activated by a presence sensor being in communication with the control unit. Such an embodiment offers the advantage of a reduced energy consumption while maintaining the appearance of the space being illuminated by the light emitting device.

According to the present invention, the light emitting device further comprises a rim arranged along at least one of the first edge and the second edge. The rim may be arranged at the reflector opening along the entire longitudinal extension of the reflector, or along a portion thereof, and borders a light exit window of the light emitting device. When the rim is arranged along only one of the edges, the light emitting device will be asymmetric having the LED light sources, and possibly also the peripheral portion on only one side of the light emitting device, thus creating an asymmetric beam. Preferably, the rim is arranged along both the first and the second edges of the reflector along the entire longitudinal extension of the reflector. The rim comprises an inner surface facing the (linear) cavity. The light emitting device further comprises a peripheral LED light source and a central LED light source, the peripheral and central LED light sources being arranged on the inner surface of the rim such that the peripheral LED light source is arranged more remote from the light exit window than the central LED light source, for example, in between the central LED light source and the reflector wall. Typically, the central LED light source is arranged more proximate to the central line (CL) than the peripheral LED light source.

The peripheral LED light source is arranged to, in operation, to emit first light towards a peripheral portion of the (inner surface of the) reflector, and the central LED light source is arranged to, in operation, to emit second light towards a central reflector portion of the (inner surface of the) reflector. The first light is redirected as reflected first light upon reflection at the peripheral reflector portion, the second light is redirected as reflected second light upon reflection at the central reflector portion. The device light is essentially composed of reflected first light and/or reflected second light. Essentially, neither first light nor second light is issued directly through the light exit window without being reflected. Thereto, typically said peripheral LED light source is arranged directly opposite the peripheral reflector portion and said central LED light source is arranged directly opposite the central reflector portion.

The light emitting device may comprise a plurality of LED light sources each comprising a plurality of LEDs arranged in a row, wherein the LED light sources are arranged substantially parallel to each other. Preferably, the peripheral LED light source comprises first and second peripheral LED light sources which, preferably, are comprised of rows of LEDs and the central LED light source comprises first and second central LED light sources, which, preferably are comprised of rows of LEDs. Said rows of LEDs preferably extend in parallel to the central line (CL). The first peripheral light source and the first central light source are mounted on an inner surface of a first rim of the rim, and the second peripheral light source and the second central light source are mounted on an inner surface of a second rim of the rim.

The first light may have a dominant wavelength in a first wavelength range, wherein the second light may have a dominant wavelength range in a second wavelength range. The first wavelength range may be different from the second wavelength range.

According to the present invention, the light emitting device further comprises a divider between said peripheral and said central LED light sources such that at least the majority of the second light is screened from directly impinging on the peripheral reflector portion. Thus, for example, interference between first light and second light of the peripheral and respectively the central LED light sources is counteracted/limited. By the term “interference” is understood that the first and the second light do not completely overlap (before being reflected), such that a tunable intensity distribution of the device light is possible, e.g. a Lambertian distribution, a batwing distribution and an asymmetric distribution.

The divider may be arranged on the inner surface of the rim. The inner surface of the rim may comprise a stepped profiled structure as the divider. The divider may protrude substantially perpendicularly to the inner surface of the rim. The main purpose of the divider is screening/blocking the first light from directly impinging on the peripheral reflector portion, for example to limit interfering with the second light and vice versa. Preferably, the divider is arranged along the entire longitudinal extension of the rim. The size and shape of the divider, as well as the angle between the divider and the inner surface of the rim may vary and depends on the desired application of the light emitting device, as well as the design of the peripheral and the central LED light sources.

The peripheral LED light source may comprise a plurality of LEDs arranged in a first row running substantially parallel to the longitudinal extension of the light emitting device. In analogy, the central LED light source may comprise a plurality of LEDs arranged in a second row running substantially parallel to the longitudinal extension of the light emitting device.

The light emitting device may comprise a plurality of LED light sources arranged between the peripheral and the central LED light sources. Such an embodiment offers the advantage of increased flexibility of the device light since intensity distributions of the light provided by each LED source may be adjustable. Having LED light sources emitting light having different intensities may further be advantageous in order to reduce glare of the light emitting device. When a plurality of LED light sources is present, a divider may be present between each two LED light sources, such that the light from each LED light source is screened and/or blocked from interfering with the light emitted by the other LED light sources.

It should be noted that the LEDs of at least the peripheral LED light source may be placed at an angle relative the inner surface of the rim, and/or relative the LEDs of the central LED light source. Such an embodiment offers the advantage of improved separation between the first and the second light.

Each of the LED light sources may emit light having a dominant peak wavelength in a wavelength range being different from the wavelength ranges of the light emitted by the other LED light sources, thus providing a possibility to obtain different spectra and thus different CCTs in the different beams of the device light. Another advantage of such an embodiment is a possibility to enable a horizontal light distribution with a higher MDER (Human Centric Light effect) and functional lighting with e.g. 4000K.

Each LED light source may be pixelated in order to allow CCT tuning, e.g. 3000K, 4000K, 5000K and 6500K, depending on the application and/or time of the day (follow daylight curve).

The rim may have the feature that the stepped profile divides the rim in a proximal portion arranged adjacent to the peripheral portion of the reflector and a distal portion arranged at a distance from the peripheral portion of the reflector. In such an embodiment, the peripheral LED light source is arranged on the proximal portion of the rim and the central LED light source is arranged on the distal portion of the rim. In particular, the proximal portion and the distal portion may be arranged in different parallel planes, e.g. such that the central LED light source is positioned at a lower height relative to the peripheral LED light source. The term “height” in this context means the distance between the surface to be illuminated and the LED light source. In other words, the distance between the surface to be illuminated and the central LED light source may be shorter than the distance between the surface to be illuminated and the peripheral LED light source.

In an alternative embodiment, the peripheral and the central LED light sources may be arranged at the same height. In such an embodiment the first and the second light may be separated from each other by an optical element, e.g. a linear lens, preferably being reflective on one side thereof. In other words, the divider in such an embodiment is in the form of the optical element. When the LED light source comprises a plurality of LEDs, the optical element may be individual for each LED, or may be a linear optic covering all the LEDs in the LED light source.

According to another embodiment, the first and the second light may be separated from each other by the divider being in the form of a (vertical) plate, a louver or a mirror arranged between the peripheral and the central LED light sources. When the divider is in the form of a mirror, optical efficiency is increased.

It is further conceivable that the linear cavity is in the form of a rotational architecture, e.g., downlight.

The light emitting device according to the present invention may further comprise a housing arranged to accommodate the reflector. The present invention further relates to a luminaire comprising a light emitting device as described above, preferably further comprising mounting means, such as suspension cables, hooks and/or clips for gripping around a T-grid of a false ceiling, for mounting the luminaire to a wall or a ceiling. Typically the luminaire may be an open cavity luminaire wherein the light exit window is open, i.e. free from, for example, a lid, plate, cover and/or optical element.

BRIEF DESCRIPTION OF THE DRAWINGS

This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiment(s) of the invention.

Fig. 1 shows a schematic cross-sectional side view of a light emitting device according to a first embodiment of the invention;

Fig. 2 shows a schematic cross-sectional side view of a light emitting device according to a second embodiment of the invention;

Fig. 3 shows a perspective view of a light emitting device according to a third embodiment of the invention;

Fig. 4 shows a perspective view of a luminaire according to an embodiment of the invention;

Figs. 5-8 show light distributions produced by the light emitting device depicted in Fig. 2.

As illustrated in the figures, the sizes of layers and regions are/can be exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of embodiments of the present invention. Like reference numerals refer to like elements throughout.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

Figs. 1 depicts a cross-sectional and a perspective view, respectively, of a first embodiment of a linear light emitting device 1 according to the present invention. As mentioned above, the light emitting device 1 according to the present invention is adapted for emitting device light 24 having an adjustable beam profile. The beam profile of the device light 24 provided by light emitting device of the present invention may e.g. have a shape of a batwing, may be Lambertian or droplet-like. Preferably, the device light 24 has a batwing beam profile.

The first embodiment of the light emitting device 1 according to the invention comprises an elongated reflector 2 with a reflector opening 23 and a cross sectional extension T. The reflector 2 is curved around a central line CL and delimits a cavity 3. Said reflector 2 comprises mutually opposite first 4 and second edge 5 on either side of the central line CL, spaced apart by said transverse extension T of said reflector 2, and bordering said reflector opening 23. The reflector 2 further comprises a reflector wall 7 having an inner reflector surface 6 facing said cavity 3. A rim 10 is connected to said first edge 4 at said reflector opening 23 and extends along the central line CL. Said rim 10 borders said light exit window 22 and comprises an inner rim surface 11 facing said cavity 3. Said light emitting device 1 further comprises a peripheral LED light source 12 and a central LED light source 13, said peripheral and central LED light sources 12,13 being arranged on said inner surface 11 of said rim 10 and face away from the light exit window 22. Said peripheral LED light source 12 is arranged to emit, in operation, first light 14 towards a peripheral reflector portion 9 of the reflector 2. Said central LED light source 13 is arranged to emit, in operation, second light 15 towards a central reflector portion 8 of the reflector 2. The cross-sectional shape of the reflector 2 is substantially parabolic. The central reflector portion 8 is concavely curved towards the cavity 3 around the central line CL and has a(n average) first radius of curvature. The peripheral reflector portion 9 is also concavely curved towards the cavity 3 around the central line CL and has a(n average) second radius of curvature. Said first radius of curvature is larger than said second radius of curvature. The peripheral reflector portion 9 of the reflector 2 may be substantially invisible to the observer, thus offering the advantage of aesthetically appealing light emitting device 1 combined with improved performance in terms of light distribution.

The inner surface 6 of the central reflector portion 8 may be non-specular. In particular, the inner surface 6 of the central reflector portion 8 may be white. The inner surface 6 of the peripheral reflector portion 9 may be at least partially specular. Said light emitting device 1 further comprises a divider 16, between said peripheral and said central LED light sources 12,13, in the first embodiment as depicted in an angled orientation with respect to the inner rim surface at an angle of about 70 degrees, such that at least the majority of the second light 15 is screened from directly impinging on the peripheral reflector portion 9. Hence, first light 14 is for its major part reflected by the peripheral reflector portion 9 and becomes reflected first light and second light 15 is for its major part reflected by the central reflector portion 8 and becomes reflected second light. The divider 16 is arranged along the entire longitudinal extension of the rim 10. The size and shape of the divider 16, as well as the angle between the divider 16 and the inner surface 11 of the rim 10 may vary and depends on the desired application of the light emitting device 1, as well as the design of the peripheral and the central LED light sources 12, 13. The main purpose of the divider 16 is directing the major portion of the second light 15 towards the inner surface 6 of the central portion 8. By the term “major portion” is understood as at least 50%. The peripheral reflector portion 9 may be in the form of small reflector parts that can be specular or semi-specular, thus reflecting light in a (possibly quite small) cone of directions around the specular direction, as shown in Figs. 1-2. The more specular the peripheral reflector portion 9 is, the more control of beam shaping is possible. On the other hand, a lower degree of specularity of the peripheral reflector portion 9 provides less glare of the light emitting device 1 under large angles, i.e. in the direction being substantially parallel with the transverse extension T of the light emitting device 1, and also in the longitudinal direction. The device light 24 as issued from the light emitting device 1, when in operation, is essentially formed by the first reflected light and/or the second reflected light. The divider 16 between the peripheral and the central LED light sources 12, 13 counteract (too much) undesired interference between the first light

14 and the second light 15. Since the first and the second light 14, 15 do not completely overlap, tunable intensity distribution of the device light is possible, e.g. a Lambertian distribution, a batwing distribution and an asymmetric distribution. There might be a portion of the first light 14 emitted by the peripheral LED light source 12 that will hit the inner surface 6 of the central portion 8. Further, it is conceivable that a portion of the second light

15 emitted by the central LED light source 13 hits the inner surface 6 of the peripheral portion 9.

The light emitting device 1 according to the present invention as shown in Fig. 2 is of a similar construction as the embodiment of the light emitting device according to the invention as shown in Fig.l, yet still is different in various aspects therefrom. The embodiment of the light emitting device 1 shown in Fig. 2 comprises a first rim 10,10a and second rim 10,10b connected to respectively said first 4 and said second edge 5 at said reflector opening 23 and extending along the central line CL. Said first and second rim 10, 10a, 10b bordering said light exit window 22 and comprising a first 11, I la and second 11,1 lb inner rim surface facing said cavity 3. Said light emitting device 1 further comprises a first 12,12a and a second peripheral LED light source 12,12b and a first 13,13a and a second central LED light source 13, 13b. Said peripheral 12, 12a, 12b and central LED light sources 13, 13a, 13b being arranged on said inner surface 11,1 la, 11b of said rim 10, 10a, 10b and facing away from the light exit window 22. As may be seen in Fig. 2, the peripheral LED light source 12 comprises two LEDs arranged in a first row running substantially parallel to the central line CL. In analogy, the central LED light source 13 comprises two rows of LEDs arranged substantially parallel to the central line CL. Each inner rim surface 11,1 la, 1 lb of the first and second rim 10, 10a, 10b comprises a multi-stepped profile structure, of which one step functions as a divider 16 between said peripheral 12, 12a, 12b and said central LED light sources 13, 13a, 13b. This divider 16 extends perpendicular to the inner rim surface 11,1 la, 1 lb and divides each rim 10, 10a, 10b in a respective proximal portion 17 arranged adjacent to said peripheral reflector portion 9 and a respective distal portion 18 arranged at a distance from said peripheral reflector portion 9, and wherein said proximal portion 17 and said distal portion 18 are arranged in different planes that extend parallel to the light exit window 22. Because of the presence of the divider 16, at least the majority of the second light 15 is screened from directly impinging on the peripheral reflector portion 9.

Fig. 3 shows a perspective view of a third embodiment of the light emitting device 1 according to the invention of a similar construction as shown in Figs. 1 and 2. The light emitting device 1 comprises a reflector 2 having a longitudinal extension in the direction along a central line CL and a cross sectional, transverse extension T being substantially perpendicular to the longitudinal extension, wherein the longitudinal extension of the reflector 2 is substantially parallel to the longitudinal extension of the light emitting device 1. The longitudinal extension of the reflector 2 is equal to the longitudinal extension of the light emitting device 1. The reflector 2 delimits a linear cavity 3 and comprises a first edge 4 and a second edge 5 arranged substantially parallel to the longitudinal extension of the light emitting device 1. The reflector 2 has a wall 7 which comprises an inner surface 6 facing the linear cavity 3. The first and the second edges 4, 5 are spaced apart by the transverse extension of the reflector 2. The light emitting device 1 further comprises rims 10, 10a, 10b arranged along the first edge 4 and the second edge 5. The rims 10, 10a, 10b are arranged along the entire longitudinal extension L of the reflector 2. In the embodiment depicted in Fig. 3, the first and the second edges 4,5 are substantially parallel to each other. Each rim 10, 10a, 10b comprises a single stepped profile, of which the step functions as the divider 16. This divider 16 extends perpendicular to the inner rim surface 11,1 la, 1 lb and divides each rim 10, 10a, 10b in a respective proximal portion 17 arranged adjacent to said peripheral reflector portion 9 and a respective distal portion 18 arranged at a distance from said peripheral reflector portion 9, and wherein said proximal portion 17 and said distal portion 18 are arranged in different planes that extend parallel to the light exit window 22. The light emitting device 1 further comprises an peripheral LED light source 12 and an central LED light source 13, the peripheral and central LED light sources 12, 13 being arranged on the inner surface 11,1 la, 1 lb of respectively a proximate portion 17 respectively a distal portion 18 of the rims 10, 10a, 10b such that the peripheral LED light source 12 is arranged between the central LED light source 13 and the reflector 2.

The rim 10 has the proximal portion 17 arranged adjacent to the peripheral portion 9 of the reflector 2 and the distal portion 18 arranged at a distance from the peripheral portion 9 of the reflector 2. The peripheral LED light source 12 is arranged on the proximal portion 17 of the rim 10 and the central LED light source 13 is arranged on the distal portion 18 of the rim 10. As shown in Figs. 2-3, the proximal portion 17 and the distal portion 18 are arranged in different planes parallel to the light exit window 22, e.g. such that the central LED light source 13 is positioned at a lower height relative the peripheral LED light source 12. The term “height” in this context means the distance between the surface to be illuminated and the LED light source. In other words, in a direction perpendicular to the light exit window 22, the distance between the light exit window 22 and the central LED light source 13 is shorter than the distance between the light exit window 22 and the peripheral LED light source 12.

Fig. 4 shows a perspective view of a luminaire 100 according to an embodiment of the invention. The luminaire 100 comprises a housing 110 which accommodates the light emitting device of Fig. 1. The housing 110 further accommodates a sensor 120 (indicated in ghost), enabling remote control by a user of the light emitting device 1. The housing has mounting means 130, in the Fig. 4 a pair of suspension cables, to mount the luminaire to a wall or a ceiling.

Turning the attention to the beam shapes of the device light provided by the light emitting device 1 shown in Figs. 5-8. The light distribution of the central reflector portion 8 and the peripheral reflector portions 9 may be selected such that one portion may create a wide distribution to improve spatial brightness while the other portions can provide a narrower distribution to improve task illumination. In such an embodiment, the light emitting device 1 may comprise a control unit (not shown) for controlling the light distribution provided by the different portions of the reflector 2. For instance, the task illumination may be activated by a presence sensor being in communication with the control unit. Such an embodiment offers the advantage of a reduced energy consumption while maintaining the appearance of the space being illuminated by the light emitting device. Fig. 5 shows light distributions produced by the light emitting device depicted in Fig. 2, wherein both outer left and outer right LED light sources 13 are operating. As may be seen in Fig. 6, the light distributions produced by the light emitting device 1 change when only right central LED light source 13 is operating. When peripheral left and peripheral right LED light sources 12 are operating, the light distribution has a batwing profile, shown in Fig. 7. An asymmetric light distribution profile is produced by the light emitting device 1 depicted in Fig. 2, wherein only left peripheral LED light source 12 is operating, as shown in Fig. 8.

The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the features of the different embodiments described herein may be combined in different ways.

Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. 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.

Claims

CLAIMS:

1. A light emitting device (1) adapted for emitting through a light exit window

(22) device light (24) having an adjustable beam profile, said light emitting device (1) comprising: an elongated reflector (2) with a reflector opening (23) and a cross sectional extension (T), the reflector being curved around a central line (CL) and delimiting a cavity (3), said reflector (2) comprising: mutually opposite first and second edge (4,5) on either side of the central line (CL), spaced apart by said transverse extension (T) of said reflector (2), and bordering said reflector opening (23), and a reflector wall (7) having an inner reflector surface (6) facing said cavity (3), a first rim (10,10a) connected to said first edge (4) at said reflector opening

(23) and extending along the central line (CL), said first rim (10,10a) bordering said light exit window (22) and comprising a first inner rim surface (11,11a) facing said cavity (3), said light emitting device (1) further comprising a first peripheral LED light source (12) and a first central LED light source (13), said first peripheral and first central LED light sources (12, 13) being arranged on said first inner rim surface (11, 1 la) of said first rim (10,10a) and facing away from the light exit window (22), said first peripheral LED light source (12) being arranged to emit, in operation, first light (14) towards a peripheral reflector portion (9) of the reflector (2), said first central LED light source (13) being arranged to emit, in operation, second light (15) towards a central reflector portion (8) of the reflector (2), wherein said light emitting device (1) further comprises a divider (16) between said first peripheral and said first central LED light sources (12,13) such that at least the majority of the second light (15) is screened from directly impinging on the peripheral reflector portion (9), wherein said inner surface (6) of said central reflector portion (8) is non- specular, and wherein said inner surface (6) of said peripheral reflector portion (9) is at least partially specular.

2. The light emitting device (1) according to claim 1 further comprising a second rim (10,10b) connected to said second edge (5) at said reflector opening (23), bordering said light exit window (22), and comprising a second inner rim surface (11,1 lb), wherein second peripheral and second central LED light sources (12,13) are arranged on the second inner rim surface (11,11b) of the second rim (10,10b).

3. The light emitting device (1) according to claim 1 or 2, wherein the light emitting device (1) is linear and has a longitudinal extension (L) substantially perpendicular to said cross sectional extension (T).

4. The light emitting device (1) according to claim 1, 2 or 3, wherein the inner rim surface (11) of each rim (10) comprises a stepped profiled structure as the divider (16).

5. The light emitting device (1) according to claim 1, 2, 3, or 4, wherein said divider (16) is arranged substantially perpendicularly to said inner rim surface (11) of each rim (10).

6. The light emitting device (1) according to any one of claims 1 to 5, wherein in said cross sectional extension (T) said central reflector portion (8) and said peripheral reflector portion (9) have a respective concave curvature towards the cavity (3).

7. The light emitting device (1) according to claim 6, wherein the curvature of the peripheral reflector portion has a smaller average radius than the average radius of the curvature of the central reflector portion.

8. The light emitting device (1) according to any one of the preceding claims, wherein said light emitting device (1) is elongated.

9. The light emitting device (1) according to any one of the preceding claims, wherein each peripheral LED light source (12) comprises a plurality of LEDs arranged in a first row running substantially parallel to said longitudinal extension (L) of said light emitting device (1), and wherein each central LED light source (13) comprises a plurality of LEDs arranged in a second row running substantially parallel to said central line (CL) of said light emitting device (1).

10. The light emitting device (1) according to any one of the preceding claims, wherein said rim (10) has a proximal portion (17) arranged adjacent to said peripheral portion (9) of said reflector (2) and a distal portion (18) arranged at a distance from said peripheral portion (9) of said reflector (2), and wherein said proximal portion (17) and said distal portion (18) are arranged in different parallel planes.

11. The light emitting device (1) according to claim 10, wherein each peripheral LED light source (12) is arranged on said proximal portion (17) of each rim (10) and each central LED light source (13) is arranged on said distal portion (18) of each rim (10).

12. The light emitting device (1) according to any one of the preceding claims, wherein said light emitting device (1) comprises a plurality of LED light sources each comprising a plurality of LEDs arranged in a row, wherein said LED light sources are arranged substantially parallel to each other.

13. The light emitting device (1) according to any one of the preceding claims, wherein said light emitting device (1) further comprises a housing arranged to accommodate said reflector (2).

14. The light emitting device (1) according to any one of the preceding claims, wherein said first light (14) has a dominant wavelength in a first wavelength range, wherein said second light (15) has a dominant wavelength range in a second wavelength range, and wherein said first wavelength range is different from said second wavelength range.

15. A luminaire comprising a light emitting device (1) according to any one of the above claims and mounting means (130) for mounting the luminaire.