EP4610549A1

EP4610549A1 - Luminaire and system for building a luminaire

Info

Publication number: EP4610549A1
Application number: EP24160785.2A
Authority: EP
Inventors: Thomas Kelly; Raymond Keane; Anton Bowness
Original assignee: Thorn Lighting Ltd
Current assignee: Thorn Lighting Ltd
Priority date: 2024-03-01
Filing date: 2024-03-01
Publication date: 2025-09-03
Also published as: WO2025181297A1

Abstract

A luminaire (100) is provided, preferably in the form of a recessed or surface-mounted luminaire, comprising a luminaire housing (10), a light source (15) arranged in the luminaire housing (10), which is formed by an elongated arrangement of LEDs or LED clusters arranged on at least one printed circuit board and extending along a central area of the luminaire housing (10), such that side areas (40) are formed on both sides of the light source (15), and light emitting elements (30, 50) closing the luminaire housing (10), wherein lenses (20) are associated with the LEDs or LED clusters, which are configured to direct a first part of the light emitted by the associated LED or LED cluster to a region formed in front of the lenses (20) and emit a second part of the light laterally, so that this light can enter the side areas of the luminaire 100).

Description

The present invention is directed to a luminaire, in particular a recessed luminaire, which uses for example a louvre for a direct emission of light and in addition provides for an additional emission of light by means of a side coffer. In addition, the present invention is directed to a system for building luminaires having different light emission characteristics.
A luminaire with a corresponding light emission as mentioned above and which uses a louvre for direct light emission is for example known from European patent EP 1 255 950 B1 . The light emission mechanism of this known luminaire is designed to achieve uniform light distribution and create various lighting effects while maintaining a sleek and low-profile appearance. The luminaire uses a tubular gas discharge lamp as the primary light source. Light from this lamp is directed downwards through a raster or grid composed of side reflectors and transverse lamellae, which helps to evenly distribute the light and reduce glare, making it particularly suitable for use in environments with computer workstations. Additionally, the luminaire incorporates one or more concavely curved reflectors positioned next to the lamp. These reflectors, along with at least one partially light-permeable diffuser arranged before the reflector, enclose at least one so-called light chamber on each side of the lamp. This arrangement ensures that light is evenly spread out, enhancing the luminaire's ability to illuminate a space without causing discomfort from direct glare.
Gas discharge lamps are now usually replaced by longitudinal arrays of LEDs. However, the resulting louvre cell luminaires are still very directional in terms of light distribution. The light source, now formed by an elongated PCB with multiple LEDs, is positioned within the cell and the cell geometry controls the distribution accordingly. In the case of recessed luminaires, this again results in dark/unlit chambers on either side of the louvre. If these need to be illuminated, then additional LEDs/PCBs are typically required or the overall height of the louvre is reduced, resulting in less control of the direct light.
Accordingly, the present invention aims to provide a solution that enables efficient control of direct light emission through a louvre, while at the same time allowing areas on one side of the louvre to be illuminated with little effort. In particular, the need for an additional light source that specifically illuminates the side coffers of a luminaire is to be avoided.
The above object is solved by a luminaire as defined in independent claim 1. Preferred embodiments of the present invention are subject matter of the dependent claims.
The present invention proposes to use, as primary optics, special lenses that provide a dual lens distribution, allowing light to be distributed horizontally and also vertically from a minimum number of LED light sources, thus allowing light to illuminate the coffer areas of the luminaire, as well as allowing light to pass through the louvres for the more controlled distributions. As no additional light sources are required and the LED light source array is central and hidden by the louvre components, the aesthetic challenges associated with using additional light sources in the coffer areas are overcome. The overall result is a new aesthetically pleasing lighting appearance with a reduced number of components. In particular, the light distribution obtained by the ingenious lens arrangement allows the use of different light emission components, which makes it possible to create very different luminaires, all based on the same basic platform.
Accordingly, in accordance with the present invention, a luminaire is provided, preferably in the form of a recessed or surface-mounted luminaire, comprising

a luminaire housing defining a light emission area,
a light source arranged in the luminaire housing, which is formed by an elongated arrangement of LEDs or LED clusters arranged on at least one printed circuit board and extending along a central area of the luminaire housing, such that side areas or coffers are formed on both sides of the light source,
light emitting elements closing the luminaire housing,

Preferably, the LEDs or LED clusters form one or two rows. These rows extend centrally through the luminaire housing from one end to the opposite end. This configuration ensures a uniform distribution of light throughout the luminaire, enhancing its overall illumination capabilities. By aligning the LEDs or LED clusters in this manner, the luminaire achieves optimal light dispersion and coverage, resulting in improved visibility and aesthetics in the illuminated space. In a preferred embodiment of the present invention, the lenses associated with the LEDs or LED clusters are rotationally symmetrical. This symmetrical lens design helps to achieve uniform light distribution and minimizes glare. By ensuring rotational symmetry, the luminaire maintains consistent lighting performance from different viewing angles, thereby enhancing user comfort and visual appeal. In addition, this feature contributes to the overall efficiency and effectiveness of the luminaire by maximizing light output and minimizing energy wastage, whilst avoiding the need for additional light sources to illuminate the cassettes.
Preferably, the lenses are firmly attached to the printed circuit board carrying the LEDs or LED clusters. This integration of lenses onto the PCB provides several advantages. Firstly, it ensures precise alignment and positioning of the lenses relative to the light source, optimizing light control and distribution. Secondly, it enhances the durability and reliability of the luminaire by securely fastening the lenses, minimizing the risk of displacement or damage during operation or handling. Additionally, this configuration simplifies the assembly process and reduces manufacturing costs, making the luminaire more cost-effective and accessible to consumers.
Preferably, the side areas of the inventive luminaire have a reflective surface. This surface extends from the light sources to a side wall of the luminaire housing. By integrating reflective surfaces into the luminaire design, the efficiency of light output is significantly enhanced and a homogeneous illumination of the coffers is ensured. The reflective surface within the luminaire is specifically concave, with a curvature that enhances its reflective properties.
As mentioned above, the inventive arrangement of LED light sources and associated lenses as primary optics allows the use of very different types of light emitting elements. Specific examples of combinations are provided in some of the dependent claims.
In a first preferred embodiment, the light emitting elements closing the luminaire housing comprise:

a) a central light emitting element, which is positioned following the lenses in the direction of light emission and is designed to emit the first part of the light directed by the lenses, as well as
b) lateral light emitting elements arranged on both sides of the central light emitting element and extending from the central light emitting element to a wall area of the housing,

Similar to the luminaire known from the prior art, the central light emitting element could be a louvre. In particular, the louvre can be formed by a grid-like arrangement of several reflector cells, each of which forming a ring-like closed wall with a reflective surface which extends from a light entry opening of the associated reflector cell to a light exit opening of the reflector cell, wherein preferably the light exit openings of all the reflector cells are substantially in a common first plane. Using the louvre as central light emitting element allows to illuminate working places with high intensity and quality and to avoid disturbing reflections.
As an alternative to the louvre, the central light emitting element could be made of a translucent material. This element then preferably forms a plate-shaped light emitting area responsible for emitting the first part of the light. The design of this light emitting area incorporates either a diffusing material or a special structure such as a lens or prism structure. This design ensures optimum dispersion and diffusion of the light, resulting in uniform illumination over the central portion, whilst still directing the emitted light to the desired areas. This configuration allows for creative lighting effects and aesthetic enhancements, making the luminaire suitable for a wide range of lighting applications.
In the two examples mentioned before, the central light emitting element of the luminaire could be designed to be partially translucent, particularly when facing the side areas. This translucent property enables part of the emitted light to be directed into the side areas or onto the lateral light emitting elements of the luminaire. By strategically channeling a (minor) part of the light towards these areas, the luminaire achieves improved lighting uniformity and coverage, enhancing visibility and ambiance within the illuminated space.
In another preferred embodiment, the light emitting elements closing the luminaire housing comprise:

a) a central shield, which is positioned downstream of the lenses and is opaque, whereby light falling on the shield is preferably scattered or reflected into the side areas of the luminaire,
b) lateral light emitting elements arranged on both sides of the shield and extending from the shield to a wall area of the housing, wherein the second light emitting elements emit the light emitted by the lenses into the side areas.

In this case, the luminaire primarily provides uniform light emission via the lateral light emission elements, which can be used for general illumination of rooms or surfaces. The proportion of directional light is low, making this version less suitable for illuminating work areas. As the central part is no longer used for light emission, this part could also be used for other purposes, e.g. for holding sensors or other comparable elements.
In case a central light emitting element or a central shield is used, the lateral light emitting elements preferably are each formed by a diffuser, which is preferably concave curved.
It would also be possible to dispense with a central light emitting element or a shield. In this case, the light emitting elements that close off the luminaire housing preferably consist of two covers that extend from opposite sides of the luminaire housing to the center below the light source and are preferably concave, in particular concavely curved. Alternatively, the light emitting elements closing off the luminaire housing can also consist of a single diffuser that closes off the luminaire housing in a flat or concave curved shape.
These various embodiments show that the basic structure of the luminaire, including the light sources and the associated primary lenses, results in a versatile light engine which can be used to provide luminaires with different appearances and different light emission characteristics in which the light provided by the light sources is efficiently utilized for a high quality emission.
The present invention also provides a system for building a luminaire, said system comprising:

i. a light engine unit comprising:
- a luminaire housing defining a light emission area,
- a light source arranged in the luminaire housing, which is formed by an elongated arrangement of LEDs or LED clusters arranged on at least one printed circuit board and extending along a central area of the luminaire housing, such that side areas are formed on both sides of the light source,
- lenses which are associated with the LEDs or LED clusters, which are configured to direct a first part of the light emitted by the associated LED or LED cluster to a region formed in front of the lenses and emit a second part of the light laterally, so that this light can enter the side areas of the luminaire,
ii. a plurality of different light emitting elements which are combinable with the luminaire housing to close the housing.

In the following, the present invention is discussed in more detail with respect to the accompanying drawings.

Figure 1 shows a first embodiment of an inventive luminaire.
Figure 2 shows the luminaire of Figure 1 installed in a ceiling.
Figure 3 shows a cross-sectional view of the luminaire of Figures 1 and 2.
Figure 4 shows an enlarged portion of the sectional view of Figure 1.
Figures 5 to 7 show different luminaires using the inventive arrangement of LED boards with associated lenses.
Figures 8a and 8b show the possibility of adding an optional sensor to the inventive light. luminaire.

In the recessed ceiling luminaire shown in Figures 1 to 4 and generally marked with the reference sign 100, the various components of the luminaire 100 are arranged inside a box-shaped luminaire housing 10 which, when the luminaire 100 is installed, is recessed in the ceiling of a room to be illuminated. The housing 10 may have laterally protruding edge strips 10a at its edge regions which, when the housing 10 is inserted into a mounting opening in the ceiling, can completely close the mounting opening. In addition, these edge strips 10a can also have or support brackets - not shown - which allow adaptation to the thickness of the ceiling and thus ensure that the luminaire housing 10 is always flush with the surrounding ceiling or a corresponding support structure.
Within the housing 10, there is a generally longitudinal arrangement of LEDs serving as the light source 15 for the luminaire 100 and extending through the center of the luminaire housing 10. The light from these LEDs is emitted through the light exit aperture formed on the front or underside of the housing 10, the light being in the shown embodiment emitted via a central light emitting element formed by a louvre 30 and additionally via two additional light emission areas 40 on either side of the louvre 30.
In order to ensure that the light emitted by the LEDs is used completely and effectively for illumination, two optional wing-like reflectors (not shown in the figures) may be provided, which extend within the housing 10 on both sides of the light source 15 towards the edge region of the housing 10 and form two curved coffers. These optional reflectors preferably are designed to be concave, preferably concavely curved, as this special shape allows a very uniform additional light emission. However, as shown in Figures 1 to 4, it is also possible to use the pure box structure of the housing 10 for the formation of the two coffers, which also allows the additional light emission.
Louvre 30 comprises a plurality of reflector cells 31 arranged in a grid-like pattern. This arrangement creates a structured path for the light that passes through and is influenced by the louvre 30. Light that is emitted in this form makes it possible, for example, to illuminate working places with high intensity and quality and to avoid disturbing reflections. In the embodiment shown in the figures, the cells 31 are arranged in two neighboring rows 31₁ and 31₂ along the extension of the light source 15. However, the arrangement of cells 31 also could form only one row or even more than two rows.
Each reflector cell 31 forms a ring-like, closed wall 32 which encircles the light, guiding it through the cell 31. The inner surface of these ring-like walls 32 is reflective to ensure that light is directed efficiently and losses are minimized. The inclination and/or curvature of the reflector walls 32 and the size of the reflector cells 31 can be adjusted in order to influence light in a way desired for the application. Nevertheless, preferably all cells 31 have a similar shape.
Each cell has light entry opening 33 where light enters and a light exit opening 34 where light exits. The arrangement of LED light sources preferably corresponds to the arrangement of the reflector cells 31. In other words, the light source 15 comprises again a grid-like arrangement of individual LEDs or LED clusters, where each LED / LED cluster is assigned to one of the cells 31 and is preferably located centrally above the corresponding cell 31. Accordingly, a significant proportion of the light from an LED / LED source enters the associated cell 31 via the corresponding light entry opening 33 and is directed by the reflective wall 32 before finally being emitted via the corresponding light exit opening 34.
In order to ensure a uniform appearance of the louvre 30, the shape of all the light exit openings 34 is preferably identical, wherein the light exit openings 34 can be circular or oval, but in particular are rectangular, e.g. square. All the light exit openings 34 are substantially in a common first plane which is recessed with respect to the plane of the housing opening. As will be shown later, other arrangements are also possible.
The luminaire housing 10 is closed by an arrangement of light emitting elements including the louvre 30 as central light emitting element and two additional lateral light emitting elements 50 forming a transparent cover for both coffers. Since it is desirable for the light emitted via the lateral light emission areas 40 to be distributed uniformly and homogeneously, these optical elements 50 are preferably made of a light-scattering material forming opal diffusers 55 in front of the two coffers. In order to prevent dust or small insects from entering the interior of the luminaire 100, it is also possible for this optical element 50 to completely close the housing 10 and thus also cover the bottom of the louvre 30. In this case, the corresponding part of the optical element 50 could be made of a transparent material so as not to affect the light emission of the louvre 30. However, since light diffusion only affects directed light to a certain extent, the diffusing material could also extend over the entire extent of the optical element 50, while the light emitted via the central portion is still specifically directed due to the influence of the louvre 30. This solution may be considered advantageous as it provides a more uniform appearance of the luminaire 100 when the light source 15 is deactivated.
The luminaire 100 shown in Figures 1 to 4 is intended to have similar photometric properties to the luminaires known from the prior art described above. Accordingly, on the one hand, it should direct light, i.e. emit light in certain angular areas, whereby this part of the light is directed or focused by the louvre 30. On the other hand, light is to be emitted in a non-directional or diffuse manner via the two lateral light emitting areas 40.
In contrast to known solutions, which require an additional light source for emitting light via the side areas 40, the luminaire 100 according to the present invention only makes use of a single light source arrangement. This simplification of the structure of the luminaire 100 is achieved by the use of specific primary lenses which are described in more detail in the following.
These lenses 20 are shown in Figures 1 and 2 and are individually associated with the LED light sources. Accordingly, the lenses 20 are also arranged in a grid-like pattern, each lens 20 being associated with an LED or LED cluster. In order to ensure correct alignment between the light source and the lens 20, the lenses 20 are preferably attached to the LED circuit board and thus move together with the corresponding LED / LED cluster in the event of thermal expansion. Preferably, the lenses 20 are detachably attached to the printed circuit board by means of a snap connection or a similar solution.
According to the present invention, each lens 20 is configured to direct a first part of the light emitted by the associated LED or LED cluster to a region formed in front of the lenses 20 - in the present case of Figures 1 to 4 to be emitted via louvre 30 - and emit a second part of the light laterally, so that this light can enter the side areas of the luminaire 100 to be emitted via the lateral light emitting elements 55.
As can be seen in the figures, the lenses 20 preferably have a circular configuration with a circumferential, essentially vertical side wall 21 via which light is emitted into the lateral areas of the luminaire 100, as well as an essentially horizontal base surface 22 via which the light is passed on to the louvre 30 or other central light emitting element, whereby the lens 20 tapers slightly in the lower area. On the side facing the LED or LED cluster, the lens 20 can have a recess into which the associated LED / LED cluster protrudes, which ensures that the light from the LED / LED cluster is fully utilized in the manner according to the invention.
Whilst sufficient light is still directed through the cells 31 of the louvre 30 and can be used for an efficient so-called task lighting, the lenses 20 ensure that the total amount of light entering the coffers is also sufficient to provide additional light emission via diffusers 50 without the need for additional light sources. Accordingly, the use of the inventive primary lenses 20 makes it possible to simplify the structure of the luminaire 100 and the number of parts, while achieving similar optical effects in terms of light emission.
Even more, it has been found that this light engine platform comprising the housing 10, LED light source 15 and primary lenses 20 allows to realize a plurality of totally different luminaires depending on the light emitting elements which are attached to the housing. This opens up the possibility of providing a modular system in which the luminaire housing can be fitted with different light emitting elements to provide a wide variety of luminaires that differ in terms of their appearance and light emission properties. Ultimately, this can significantly reduce the cost of manufacturing a large number of different luminaires.
In this regards, Figures 5 to 7 show a plurality of different luminaires that can be realized on the basis of the light engine explained above. All the luminaires are recessed luminaires that have a housing to accommodate, in particular, the PCBs with the LEDs or LED clusters and the lenses 20 located in front of the LEDs / LED clusters. The various examples differ in terms of the light emitting elements used to emit the light provided by the LEDs / LED clusters, these elements determining the light emission characteristics and the appearance of the luminaires. Obviously, also surface mounted luminaires could be provided in a similar way.
With respect to the first group of luminaires 100 shown in Figure 5a to 5d, a central shield or central light emitting element - if present - has an end portion which is substantially flush with the plane defined by the light emitting aperture defined by the luminaire housing 10. Lateral light emitting elements generally have a convex shape resulting in the shield or central light emitting element projecting from the adjacent lateral light emitting element with a preferably trapezoidal projection.

Figure 5a - Wave:

This variant features a trapezoidal shield 61 running down the center of the luminaire housing 10, flanked on both sides by convex diffuser 'wings' 55. Sensors can be housed within the opaque shield 61, wherein light directed by lenses 20 onto this shield is scattered or reflected to both sides and thus is used for the light emission via the side areas 40.

Figure 5b - Beam:

In this case, the central light emitting element is a co-extrusion profile 62 with a prismatic front and opal sides, creating light that reflects back onto the coffers. Optional sensors are in a small notch 90 on one side of the luminaire casing 10 protruding through the coffer. This is illustrated in more detail in Figures 8a and 8b, which show a lateral section of the lateral diffuser 55, which rests against the side wall of the housing 10. A rectangular notch 90 is formed, which is normally closed by a corresponding cover or panel. If the luminaire 100 is to be equipped with additional functionalities, this cover - not shown - is removed and a corresponding sensor element 95 is inserted into the notch, which is preferably connected to internal connection means via a plug connection. This sensor 95 could be a presence sensor or a brightness sensor that supports automatic control of the luminaire 100.

Figure 5c - Cell:

This variant is similar to the luminaire shown above in Figures 1 to 4. It is characterized by a trapezoidal louvre 30 and convex diffuser wings 55, with prismatic/opal sides allowing light onto the coffers. Again, optional sensors can be housed in a small notch 90 protruding through the coffer on one side of the luminaire housing.

Figure 5d - Flat:

This variant has an opal, prismatic or patterned flat diffuser 63, depending on the light distribution required. It maintains consistency with other members of the family through a common trapezoidal sensor notch 90 on one side of the luminaire housing 10. Although this variant aims to provide a near uniform light output across the flat panel, the central area will appear slightly brighter due to the direct light output of the first light portion from the primary lenses 20.
In the second group of luminaires shown in Figures 6a to 6d, a central light emitting element - if present - again has an end section that is essentially flush with the plane defined by the light outlet opening defined by the luminaire housing. Now the lateral light emitting elements end with their neighboring end sections at the end of the central light emitting element remote from the light source. In this case, the central light emitting element does not protrude from the neighboring lateral light emitting elements, but forms a continuous light emitting surface together with them.

Figure 6a - Wave:

This example does not comprise a specific central light emitting element. Light emission is achieved by a pair of concave lit panels 71 with a strip of polished aluminum creating a highlight at their intersection. As in all other cases, LED boards with corresponding lenses are placed behind prismatic panels for an evenly-lit appearance.

Figure 6b - Beam:

This embodiment features a pair of concave opal panels 72 on either side of a flat prismatic central beam 73, with polished aluminum strips creating highlights at the intersections. Similar to the version "Beam" discussed above, the central light emitting element is a profile with a prismatic structure to direct the first portion of light.

Figure 6c - Cell:

This embodiment is characterized by concave opal panels 74 on either side of central louvre 30, and polished aluminum strips creating highlights at the intersections.

Figure 6d - Flat:

This variant is identical to the example "Flat" mentioned above and has an opal, prismatic or patterned flat diffuser 75, depending on the light distribution required.
Finally, the third group of luminaires, shown in Figures 7a to 7d, has embodiments in which the central light emitting element - if present - is slightly recessed in the housing. The lateral light emitting elements now have an S-profile and again end with their neighboring end sections at the end of the central light emitting element facing away from the light source, forming a continuous light emitting surface with the latter.

Figure 7a - Wave:

This design has a gentle 'S' curve across the lit surface. The LED panels are behind a gently curved prismatic optic 81, creating an evenly-lit effect with a co-extruded central pinstripe for added definition and contrast.

Figure 7b - Beam:

This embodiment features a gentle 'S' curve with a brightly lit prismatic central beam 82, flanked by curved opal sections 83. It achieves a gradient secondary lit effect, with opaque pinstripes adding definition and contrast.

Figure 7c - Cell:

The luminaire is characterized by a gentle 'S' curve with a louvre 30 behind a central clear section of a co-extruded optic, and curved opal sections 84 on either side achieving a gradient secondary lit effect.

Figure 7d - Flat:

Again, this variant is identical to the example "Flat" mentioned above and has an opal, prismatic or patterned flat diffuser 85, depending on the light distribution desired.
In all cases of the second and third group of luminaires, a common trapezoidal sensor notch 90 on one side of the luminaire housing 10 can be used to accommodate an optional sensor.
Accordingly, the inventive configuration of the basic light engine makes it possible to considerably simplify the structure of a luminaire while still achieving excellent light emission characteristics. This concept is applicable to various combinations of light emitting elements, allowing the creation of a modular system for the efficient production of different luminaires.

Claims

Luminaire (100), preferably in the form of a recessed or surface-mounted luminaire, comprising:
• a luminaire housing (10) defining a light emission area,

• a light source (15) arranged in the luminaire housing (10), which is formed by an elongated arrangement of LEDs or LED clusters arranged on at least one printed circuit board and extending along a central area of the luminaire housing (10), such that side areas (40) are formed on both sides of the light source (15),

• light emitting elements (30, 50) closing the luminaire housing (10),
wherein lenses (20) are associated with the LEDs or LED clusters, which are configured to direct a first part of the light emitted by the associated LED or LED cluster to a region formed in front of the lenses (20) and emit a second part of the light laterally, so that this light can enter the side areas of the luminaire 100).
Luminaire according to claim 1,
characterized in that
LEDs or LED clusters form one or two rows, which extend centrally through the luminaire housing (10) from one end of the housing (10) to the opposite end.
Luminaire according to claim 1 or 2,
characterized in that
the lenses (20) are rotationally symmetrical.
Luminaire according to any one of the preceding claims,
characterized in that
the lenses (20) are attached to the printed circuit board carrying the LEDs or LED clusters.
Luminaire according to any one of the preceding claims,
characterized in that
the side areas (40) have an internal reflective surface, which extends from the light source to a side wall of the luminaire housing.
Luminaire according to claim 5,
characterized in that
the reflective surface is concave, particularly concave curved.
Luminaire according to any one of the preceding claims,
characterized in that
the light emitting elements (30, 50) closing the luminaire housing (10) comprise:
a central light emitting element, which is positioned following the lenses (20) in the direction of light emission and is designed to emit the first part of the light directed by the lenses (20), as well as

lateral light emitting elements arranged on both sides of the central light emitting element and extending from this to a wall area of the housing (10), wherein the second light emitting elements emit the light emitted by the lenses (20) into the side areas (40).
Luminaire according to claim 7,
characterized in that
the central light emitting element is a louvre (30), wherein the louvre is preferably formed by a number of reflector cells (31) corresponding to the number of LEDs or LED clusters.
Luminaire according to claim 7,
characterized in that
the central light emitting element consists of a translucent material and forms a plate-shaped light emitting area for emitting the first part of the light, wherein the plate-shaped light emitting area consists of a diffusing or opal material or is provided with a structure, particularly a lens or prism structure.
Luminaire according to any one of claims 8 and 9,
characterized in that
the central light emitting element is at least partially translucent facing the side areas (40), so that part of the light is emitted into the side areas (40) or onto the lateral light emitting elements, wherein the central light emitting element preferably has a trapezoidal shape.
Luminaire according to any one of claims 1 to 6,
characterized in that
the light emitting elements closing the luminaire housing comprise:
a central shield (61), which is positioned following the lenses (20) in the direction of light emission and is opaque, wherein light falling on the shield (61) is preferably scattered or reflected into the side areas (40) of the luminaire (100),

lateral light emitting elements arranged on both sides of the central shield (61) and extending from this to a wall area of the housing (10).
Luminaire according to claim 11,
characterized in that
at least one sensor, for example a presence sensor or a brightness sensor, is arranged in the area of the shield (61).
Luminaire according to any one of claims 7 to 12,
characterized in that
the lateral light emitting elements are each formed by a diffuser, which is preferably concavely curved.
Luminaire according to any one of claims 1 to 6,
characterized in that
the light emitting elements closing the luminaire housing (10) comprise two diffusers, which extend from opposite sides of the luminaire housing (10) to the center below the light source (15) and are preferably concave in shape, particularly concavely curved.
Luminaire according to any one of claims 1 to 6,
characterized in that
the light emitting elements closing the luminaire housing (10) comprise a diffuser, which closes the luminaire housing (10) flat or concave curved.
Luminaire according to any one of the preceding claims,
characterized in that
the housing (10) comprises a notch (90) for accommodating a sensor element (90), for example a presence sensor or a brightness sensor.
System for building a luminaire (100), said system comprising:
i. a light engine unit comprising:
• a luminaire housing (10) defining a light emission area,

• a light source (15) arranged in the luminaire housing (10), which is formed by an elongated arrangement of LEDs or LED clusters arranged on at least one printed circuit board and extending along a central area of the luminaire housing (10), such that side areas (40) are formed on both sides of the light source (15),

• lenses (20) which are associated with the LEDs or LED clusters, which are configured to direct a first part of the light emitted by the associated LED or LED cluster to a region formed in front of the lenses (20) and emit a second part of the light laterally, so that this light can enter the side areas of the luminaire (100),

ii. a plurality of different light emitting elements which are combinable with the luminaire housing (10) to close the housing (10).