A luminaire
The luminaire design addresses light loss in dark surfaces by using reflective polarizers and additional layers to reflect polarized light, improving efficiency while preserving aesthetics.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SIGNIFY HOLDING BV
- Filing Date
- 2026-01-15
- Publication Date
- 2026-07-30
AI Technical Summary
Luminaires with dark surfaces, such as grey and black finishes, suffer from significant light loss due to absorption, compromising efficiency while maintaining aesthetic appeal.
A luminaire design that incorporates a light engine with a reflective polarizer and a housing part featuring a second polarizer and an additional layer, allowing polarized light to be reflected rather than absorbed, maintaining a dark appearance while enhancing efficiency.
The luminaire achieves high efficiency by reflecting polarized light from dark surfaces, ensuring that most emitted light contributes to the output while maintaining an aesthetically pleasing dark appearance.
Smart Images
Figure EP2026050891_30072026_PF_FP_ABST
Abstract
Description
[0001] 2024PF80280
[0002] 1
[0003] A luminaire
[0004] FIELD OF THE INVENTION
[0005] The invention relates to a luminaire configured to provide luminaire light in a space. The luminaire has a housing of which at least a part is visible from the space. This housing part has a dark appearance, and it is arranged to receive light emitted by a light engine of the luminaire.
[0006] BACKGROUND OF THE INVENTION
[0007] In recent years, there has been a growing trend towards the use of (dark) grey and black surfaces in luminaires. While this aesthetic choice has become increasingly popular, it has resulted in a significant disadvantage in terms of the efficiency of the luminaire.
[0008] Specifically, when light is generated by the luminaire and is incident on such surfaces, a significant amount of the light is lost due to absorption.
[0009] This has led to a need for improved luminaires that can effectively address the issue of light loss on dark surfaces, while still maintaining the desired aesthetic effects.
[0010] EP4459337A1 discloses a luminaire having a light source and two polarizing filters. An inner polarizing filter is superimposed on, and at least partially covering, the light source. An outer polarizing filter is supported and spaced from the light source on an external wall. The inner and outer polarizing filters are arranged with their radiation polarization lines at right angles to each other. The walls or supporting surfaces of the inner and outer polarizing filters, which are translucent or transparent to the light emitted by the light source, are curved and spaced parallel to each other.
[0011] SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to provide a solution to enhance the efficiency of luminaires that utilize grey and black surfaces.
[0013] In a first aspect, the invention provides a luminaire configured to provide luminaire light in a space. The luminaire comprising a housing and a light engine.2024PF80280
[0014] 2
[0015] The light engine comprises a light source configured to emit unpolarized light source light, and a first polarizer configured to polarize at least part of the unpolarized light source light into polarized light engine light, the first polarizer being a reflective polarizer.
[0016] The housing comprises a housing part that is visible from the space, and that is arranged to receive the polarized light engine light.
[0017] The housing part comprises a second polarizer and an additional layer downstream of the second polarizer.
[0018] The luminaire according to the first aspect has one of a first configuration and a second configuration.
[0019] In the first configuration, the second polarizer is a reflective polarizer that is reflective for the polarized light engine light, and the additional layer is a light-absorbing layer.
[0020] In the second configuration, the second polarizer is a light-absorbing polarizer that is transmissive for the polarized light engine light, and the additional layer is a reflective layer that is reflective for the polarized light engine light.
[0021] The luminaire has a housing part that is visible from the space wherein it is installed, and that is arranged to receive the light that is emitted by the light engine. In either of the first and second configuration, this housing part has a dark appearance (such as a black or dark grey appearance) while it is still able to reflect substantially all of the incident light engine light.
[0022] Consequently, at least part of the exposed housing of the luminaire has an aesthetically pleasing dark appearance, while the luminaire still has a relatively high efficiency.
[0023] When the luminaire has the first configuration, the light-absorbing layer may be a black layer.
[0024] When the luminaire has the second configuration, the reflective layer may be specularly reflective for the polarized light source light. Alternatively, the reflective layer may be polarization-maintaining diffusely reflective for the polarized light source light.
[0025] The second polarizer of the housing part is separated from the first polarizer of the light engine by a minimum separation distance. This minimum separation distance may be at least 1 centimeter, such as at least 2 centimeters, or at least 5 centimeters, or at least 10 centimeters. The exposed housing parts that receive the light emitted by the light engine2024PF80280
[0026] 3
[0027] contribute to the aesthetical appearance of the luminaire, which benefits mainly from a minimum separation distance to the first polarizer of the light engine.
[0028] The light engine may comprise a light mixing chamber. In this case, the light source is provided in the light mixing chamber, and the first polarizer is at least part of a chamber light exit window of the light mixing chamber. To further improve the efficiency of such a luminaire, one or more inner surfaces of the light mixing chamber may comprise a reflector. The reflector may be a diffuse reflector. Alternatively, the reflector may be a specular reflector, in which case the luminaire further comprises a quarter-wave plate that is arranged at a side of the specular reflector that faces the light source.
[0029] In the luminaire according to the first aspect, the housing part that is visible from the space, and that is arranged to receive the polarized light engine light, may be further arranged to reflect the polarized light source light towards a luminaire light exit window of the luminaire. The luminaire light exit window may be transparent. The luminaire light exit window may also comprise a depolarizer for at least partly depolarizing the polarized light engine light upon passing through the luminaire light exit window.
[0030] In the luminaire according to the first aspect, the light engine may be arranged in the housing. The light source of the light engine may be a solid-state light source, such as a light-emitting diode (LED), for example a LED filament.
[0031] The luminaire according to the first aspect may be an indoor luminaire or an outdoor luminaire.
[0032] Examples of indoor luminaires are surface-mounted luminaires, such as ceiling or wall luminaires. Other examples of indoor luminaires are pendant luminaires, table or desk luminaires, floor- standing luminaires, and luminaires that can be mounted to a power track.
[0033] Examples of outdoor luminaires are facade luminaires, bollard luminaires, surface-mounted luminaires, in-ground luminaires, luminaires for urban lighting, luminaires for street lighting, luminaires for architectural lighting, and garden and / or pathway luminaires.
[0034] In the luminaire according to the first aspect, the light engine may be a lamp having a base. The luminaire then further comprises a socket, and the base of the lamp is arranged to mechanically and electrically connect the lamp in the socket.
[0035] In the luminaire according to first aspect, the light source may be arranged to emit first unpolarized light source light in a first angular range and second unpolarized light source light in a second angular range, wherein the first angular range and the second angular2024PF80280
[0036] 4
[0037] range are non-overlapping angular ranges. The first polarizer is then configured to polarize the first unpolarized light source light into polarized light engine light, while the second unpolarized light source light is comprised in the luminaire light.
[0038] BRIEF DESCRIPTION OF THE DRAWINGS
[0039] 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.
[0040] Figure 1 shows a luminaire that is mounted on a wall in a space.
[0041] Figure 2 shows the luminaire of Figure 1.
[0042] Figure 3 shows a schematic top view of the luminaire of Figures 1 and 2. Figure 4 shows a luminaire with an alternative configuration.
[0043] Figure 5 shows a luminaire with an alternative configuration.
[0044] Figure 6 shows a schematic front view of the luminaire of Figures 1 to 3. Figure 7 shows a luminaire with an alternative configuration.
[0045] The schematic drawings are not necessarily to scale.
[0046] DETAILED DESCRIPTION OF THE EMBODIMENTS
[0047] Figure 1 shows a luminaire 1000 that is mounted on a wall in a space 3000. In operation, the luminaire 1000 provides luminaire light 2000 into the space 3000. The space 3000 can be an indoor or interior space, such as a room or an office, or an outdoor space, such as a garden or an urban space. In operation, the luminaire 1000 provides a light output 2000 for illumination of the space 3000. This light output 2000 will be referred to as “luminaire light”.
[0048] Figure 2 again shows the luminaire 1000. The luminaire 1000 has a housing 1100 and a light engine 1200.
[0049] The light engine 1200 comprises a light source 1210. When the luminaire 1000 is in operation, light is emitted from the light source 1210. The light emitted by the light source will be referred to as “light source light”.
[0050] The light engine 1200 has a light exit window 1220 via which the light source light can leave the light engine 1200. The light that leaves the light engine 1200, or other words, the light that is emitted by the light engine 1200, will be referred to as “light engine light”.2024PF80280
[0051] 5
[0052] The light engine 1200 shown in Figure 2 is in the form of a lamp 1210 that can be fixed in a socket. The lamp 1210 has a base, and the luminaire 1000 further comprises a socket 1220. The base of the lamp 1210 is arranged to mechanically and electrically connect the lamp 1210 in the socket 1220. This is just an example of a suitable light engine. For the purpose of the invention, the light engine may have any suitable form and shape.
[0053] The housing 1100 shown in Figure 2 is in the form of a box with a back plate 1110, a front plate 1120, a bottom plate 1130, a top plate 1140, a first side plate 1150, and a second side plate 1160. The back plate 1110 and the bottom plate 1130 are closed plates, while each of the remaining plates has a frame that bounds a transparent window, the latter representing a light exit window of the luminaire 1000.
[0054] Each of the aforementioned plates, frames, and transparent windows can be referred to as a housing part. The transparent windows are housing parts that are transmissive for the light engine light. The back plate, the bottom plate, and the frames of the front plate, the side plates, and the top plate are housing parts that are non-transmissive, or opaque, for the light engine light.
[0055] The housing 1100 shown in Figure 2 is just an example of a suitable housing. For the purpose of the invention, the housing may have any suitable form and shape.
[0056] When the luminaire 1000 is in operation, part of the light engine light is directly incident (z.e., without any prior reflections) on one or more transmissive housing parts (z.e., the light exit windows of the luminaire 1000). Apart from a certain amount of reflection that may take place at these transmissive housing parts, this part of the light engine light will mostly leave the luminaire 1000 directly, thereby contributing to the luminaire light 2000.
[0057] The remaining part of the light engine light is directly incident on one or more of the non-transmissive housing parts (z.e., the back plate 1110, the bottom plate 1130, and the frames of the front plate 1120, the top plate 1140, the first side plate 1150, and the second side plate 1160). This part of the light engine light cannot leave the luminaire 1000 directly. Only when the light engine light is reflected by these housing parts can it leave the luminaire 1000 to contribute to the luminaire light.
[0058] When, for example for aesthetical reasons, a housing part has a dark appearance, such as a black or (dark) grey appearance, incident light will largely be absorbed by it. This absorbed light will then be lost. It cannot contribute to the luminaire light 2000, which reduces the luminous efficacy of the luminaire 1000.2024PF80280
[0059] 6
[0060] In the luminaire 1000 shown in Figure 2, measures have been taken to minimize light losses due to absorption while still making use of housing parts that have a dark appearance.
[0061] Figure 3 shows a schematic top view of the luminaire 1000 of Figure 2. In other words, it shows a view along the axis 1300, in a direction from A to A’.
[0062] For the sake of clarity, only the light engine 1200 and a part of the back plate 1110 are shown in a cross-sectional view.
[0063] The light source 1210 of the light engine 1200 is provided in a light mixing chamber 1230. The light source 1210 may be a solid-state light-emitting element, such as a light-emitting diode (LED), or any other suitable light source.
[0064] The light source 1210 is arranged to emit unpolarized light source light 1211, which is incident on one or more inner surfaces of the light mixing chamber 1230. The light mixing chamber 1230 has a chamber light exit window 1240 through which light may leave the light mixing chamber 1230.
[0065] The chamber light exit window 1240 comprises a first polarizer 1241 that is capable of polarizing the unpolarized light source light 1211 into polarized light engine light 1212.
[0066] A polarizer is a component that increases the degree of polarization and must therefore extinguish a portion of transmitted light, using mechanisms that include light absorption, light reflection, or light scattering.
[0067] By far the most common polarizer is the linear polarizer, which takes two forms: an absorptive polarizer, and a reflective polarizer.
[0068] The first polarizer 1241 comprised in the chamber light exit window 1240 of the light mixing chamber 1230 is a reflective polarizer. A reflective polarizer is a polarizer that transmits one polarization of light and reflects the other polarizations, with little absorption of the light. Examples of reflective polarizers are multilayer optical film polarizers and wire grid polarizers.
[0069] The most common type of reflective polarizer used today is based on multilayer optical film (MOF) technology. AMOF reflective polarizer consists of hundreds of layers of alternating materials with carefully engineered indices of refraction. Consecutive layers will have the index of refraction approximately matched along one physical axis of the film, so that light traveling with its electric field along that axis will pass unabated. Along the orthogonal axis of the film, alternating layers possess a significant index mismatch, so light2024PF80280
[0070] 7
[0071] traveling with its electric field along that axis will reflect if its wavelength meets the Bragg condition. The thickness of each optical layer is varied from the top to the bottom of the film surfaces to ensure that all visible wavelengths are reflected. This technology is sold by 3M under the DBEF (Dual Brightness Enhancement Film) product name.
[0072] As said, the light source 1210 is arranged to emit unpolarized light source light 1211. Unpolarized light can be considered a rapidly varying random combination of p- and s-polarized light, wherein p-polarized light has an electric field polarized parallel to a plane of incidence, while s-polarized light has an electric field that is polarized perpendicular to this plane.
[0073] Being a reflective polarizer, the first polarizer 1241 is transmissive for one polarization of light and reflective for the other polarization. For example, the first polarizer 1241 is arranged to transmit p-polarized light and reflect s-polarized light. The s-polarized light cannot leave the light mixing chamber 1230, and the light engine light 1212 becomes p-polarized. Obviously, such a separation of polarizations can also take place the other way around, so that p-polarized light cannot leave the light mixing chamber 1230, and the light engine light 1212 becomes s-polarized.
[0074] Because the first polarizer 1241 is a reflective polarizer, the non-transmitted polarization can be recycled to get another chance at leaving the light mixing chamber 1230.
[0075] Additional measures may be taken to prevent light of any non-transmitted polarization from being absorbed somewhere inside the light mixing chamber 1230, so that it can be recycled instead. In other words, a large part of the unpolarized light source light 1211, and even substantially all of it, may be polarized into polarized light engine light 1212.
[0076] As said, the unpolarized light source light 1211 emitted by the light source 1210 is polarized by the first polarizer 1241 as it leaves the light mixing chamber 1230 via the chamber light exit window 1240 to become polarized light engine light 1212.
[0077] Part of the polarized light engine light 1212 is then incident on the back plate 1110 of the luminaire 1000. The back plate 1110 comprises a stack of a second polarizer 1111 and an additional layer 1112, wherein the second polarizer 1111 is arranged to receive the polarized light engine light 1212.
[0078] In Figure 3, the second polarizer 1111 is physically attached to the additional layer 1112, so that the additional layer 1112 may also be referred to as a carrier layer. Such a configuration is not required for the purpose of the invention, and instead there may be a separation or gap between the second polarizer 1111 and the additional layer 1112, as long as2024PF80280
[0079] 8
[0080] the second polarizer 1111 is arranged to receive the polarized light engine light 1212, and the additional layer 1112 is located downstream of the second polarizer 1111 (downstream as seen in a direction of propagation of the polarized light engine light 1212).
[0081] The second polarizer 1111 is a reflective polarizer that is reflective for the polarized light engine light 1212. When the luminaire 1000 is in operation, the polarized light engine light 1212 that is incident on the back plate 1110 will be reflected by the second polarizer 1111 of the back plate 1110.
[0082] Polarizations of light different from that of the polarized light engine light 1212 will be able to pass through the second polarizer 1111, to be incident on the additional layer 1112. The additional layer 1112 is a light absorbing layer with a dark appearance, such as a black or dark grey appearance, so that these other polarizations of light will be absorbed by the additional layer 1112. The additional layer 1112 may be arranged to absorb at least 80 % of the incident light, such as at least 90 %.
[0083] Depending on the polarization, light that is incident on the second polarizer 1111 of the back plate 1110 will either be reflected by the second polarizer 1111 or absorbed by the additional layer 1112.
[0084] When the incident light is unpolarized light, at least about half, but potentially most, of it will be absorbed. This means that under illumination with unpolarized light (such as ambient light that comes from the surroundings of the luminaire 1000), the back plate 1110 has a dark appearance, such as a black or dark grey appearance.
[0085] All light emitted by the light engine 1200 of the luminaire 1000 is polarized light 1212 that will be reflected by the second polarizer 1111 of the back plate 1110. This reflected polarized light engine light 1212 then has a second chance at escaping from the luminaire 1000 to contribute to the luminaire light.
[0086] The polarized light engine light 1212 that is directly incident on the back plate 1110 will not be absorbed by the back plate 1110 but instead has a chance of contributing to the luminaire light, which increases the efficiency of the luminaire 1000.
[0087] In the luminaire 1000 of Figures 1 to 3, all non-transmissive housing parts on which the polarized light engine light 1212 can be incident (either directly or indirectly) have the same configuration as the back plate 1110 (z.e. , a second polarizer 1111 arranged to receive the polarized light engine light 1212, and an additional layer 1112 located downstream of the second polarizer 1111).2024PF80280
[0088] 9
[0089] This means that the luminaire 1000 of Figures 1 to 3 has a housing 1100 with non-transmissive housing parts that have a dark appearance, while at the same time the luminaire 1000 has a high efficiency because substantially all light that is emitted by the light source 1210 contributes to the output of the luminaire 1000.
[0090] For the purpose of the invention, it is not required that all non-transmissive housing parts on which the polarized light engine light can be incident have a configuration with a light absorbing layer located downstream of a second polarizer. Even if only one of such housing parts has this configuration, the efficiency of the luminaire will already be improved. The more non-transmissive housing parts have the aforementioned configuration, the higher the efficiency will be.
[0091] As indicated in Figure 3, the second polarizer 1111 of the back plate 1110 is separated from the first polarizer 1241 of the light engine 1200 by a separation distance d. Not only the back plate 1110 has a second polarizer 1111, but also the other non-transmissive housing parts have a second polarizer 1111. In relation to all second polarizers 1111, the separation distance d has a minimum value (z.e., a minimum separation distance) of at least 1 centimeter, such as at least 2 centimeters, or at least 5 centimeters, or at least 10 centimeters. The non-transmissive housing parts contribute to the aesthetical appearance of the luminaire 1000, which benefits mainly from a minimum separation distance to the first polarizer 1241 of the light engine 1200.
[0092] Figure 3 shows a configuration wherein the second polarizer 1111 is a reflective polarizer being reflective for the polarized light engine light 1212, and wherein the additional layer 1112 is a light-absorbing layer.
[0093] The configuration of Figure 3 can be referred to as a first configuration.
[0094] Alternatively, a second configuration is also possible.
[0095] Figure 4 shows the alternative second configuration. Now the second polarizer 1111 is a light-absorbing polarizer that is transmissive for the polarized light source light 1212, and the additional layer 1112 is a reflective layer that is reflective for the polarized light engine light 1212. The reflective layer 1112 may be arranged to reflect at least 80 % of the incident light, such as at least 90 %.
[0096] In the configuration of Figure 4, it is preferred that the polarized light engine light 1212 that is reflected by the additional layer 1112 maintains it polarization state. When light is specularly reflected, the polarization is maintained. Therefore, the additional layer 1112 may be specularly reflective for the polarized light source light 1212.2024PF80280
[0097] 10
[0098] Alternatively, the additional layer 1112 may be polarization-maintaining diffusely reflective for the polarized light source light 1212. A polarization-maintaining diffusely reflective layer may comprise a material selected from the group comprising cubic crystals, stress-free glass, and isotropic transparent polymers, such as silicone rubber and PMMA. A polarization-maintaining diffusely reflective layer may comprise a surface relief. In other words, the surface of the polarization-maintaining diffusely reflective layer may comprise a (pseudo-random) microstructure of depressions and elevations. An example of a polarization-maintaining diffusely reflective additional layer is a layer with optically isotropic refractive surface structures, such as lenslet. Herein, the term “optically isotropic” refers to a material having an index of refraction that is the same in all directions.
[0099] Figure 5 shows yet another alternative configuration. Here, the back plate 1110 is similar to that of Figure 3, but now the first polarizer 1241 is only part of a side of the chamber light exit window 1240 of the light mixing chamber 1230 that faces the back place 1110.
[0100] In other words, the chamber light exit window 1240 has a first side facing towards the back plate 1110 and a second side facing away from the back plate 1110. The first polarizer 1241 is comprised in the first side of the chamber light exit window 1240, while the second side of the chamber light exit window 1240 is free of any polarizer and allows all incident light to pass through.
[0101] From the perspective of efficiency, this configuration is particularly advantageous when the luminaire is designed such that the light that passes through the second side of the chamber light exit window is not subsequently incident on a non-transmissive housing part, but instead leaves the housing as part of the luminaire light.
[0102] In the configuration of Figure 5, the luminaire 1000 has a light source 1210 that is arranged to emit first unpolarized light source light 121 la in a first angular range and second unpolarized light source light 121 lb in a second angular range. The first angular range and the second angular range are non-overlapping angular ranges. The first polarizer 1241 is configured to polarize the first unpolarized light source light 1211a into first polarized light source light 1212. The second unpolarized light source light 1211b is comprised in the luminaire light.
[0103] Figure 6 shows a schematic front view of the luminaire 1000 of Figures 1 to 3. For the sake of clarity, only the light engine 1200 and parts of the first side plate 1150 and second side plate 1160 are shown in a cross-sectional view.2024PF80280
[0104] 11
[0105] Each of the first side plate 1150 and the second side plate 1160 has a frame that bounds a transparent window. In the cross sections of Figure 6, only the frames are visible. These have a construction similar to that of the back plate 1110, viz. a second polarizer 1111 arranged to receive the polarized light engine light 1212, and an additional layer 1112 located downstream of the second polarizer 1111.
[0106] As can be clearly seen in Figure 6, the light mixing chamber 1230 has a chamber light exit window 1240 that comprises the first polarizer 1241 , and it further has an inner surface 1250 that comprises a reflector.
[0107] Any light source light that has not passed through the chamber light exit window 1240 may be incident on the inner surface 1250, from which it will then be reflected so as to get a second chance at passing through the chamber light exit window 1240.
[0108] In the light mixing chamber 1230 of Figure 6, the reflector comprised by the inner surface 1250 of the light mixing chamber 1230 is a diffuse reflector. The chance that light will still pass through the first polarizer 1241 on a second attempt has now increased because light is more likely to change polarization when it is diffusely reflected.
[0109] An alternative configuration is shown in Figure 7. Here, the reflector comprised by the inner surface 1250 of the light mixing chamber 1230 is a specular reflector, and the luminaire 1000 further comprises a quarter-wave plate 1260 that is arranged at a side of the specular reflector that faces the light source 1210. A quarter-wave plate is capable of converting linearly polarized light into circularly polarized light, and vice versa.
[0110] The configurations of Figures 6 and 7 ensure that the unpolarized light source light 1211 can be better recycled so that a large part, and even substantially all of it, may be polarized into polarized light engine light 1212, thereby contributing to an improved efficiency of the luminaire 1000.
[0111] The luminaire according to the invention is based on the insight that a housing with an aesthetically pleasing dark appearance can be combined with a relatively high efficiency. By making use of the constructions as described above, light emitted by the light engine of the luminaire, and that would otherwise be lost due to absorption at one or more dark housing parts, can now contribute to the output of the luminaire.
[0112] The light engine of the luminaire is arranged to emit polarized light, and the housing of the luminaire (or at least a part of it) is arranged to reflect the emitted polarized light.2024PF80280
[0113] 12
[0114] Each of the unpolarized light emitted by the light source (z.e., the unpolarized light source light), the polarized light emitted by the light engine (z.e., the polarized light engine light), and the light emitted by the luminaire (z.e., the luminaire light) may be white light, such as white light with a correlated color temperature in a range from 1800 K to 6500 K, or in a range from 1800 K to 2600 K, and / or with a color rendering index of at least 80.
[0115] The emitted polarized light may be reflected by the housing to a light exit window of the luminaire (z.e., to a luminaire light exit window). In the luminaire 1000 of Figures 1 to 3, the front plate 1120, the top plate 1140, the first side plate 1150, and the second side plate 1160 all have a frame that bounds a light transmissive window, the latter representing a luminaire light exit window. In the luminaire 1000, the light transmissive windows are transparent windows, but this is not required for the invention, as long as the windows are capable of letting light pass through.
[0116] The luminaire light exit window may comprises a depolarizer for at least partly depolarizing the polarized light engine light upon passing through the luminaire light exit window. A depolarizer is an optical device that is arranged to scramble the polarization of light. Various different types of depolarizers are known in the art.
[0117] 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. 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 the device 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.
[0118] 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.
Claims
2024PF8028013CLAIMS:
1. A luminaire (1000) configured to provide luminaire light (2000) in a space (3000), the luminaire comprising a housing (1100) and a light engine (1200),wherein the light engine (1200) comprises a light source (1210) configured to emit unpolarized light source light (1211), and a first polarizer (1241) configured to polarize at least part of the unpolarized light source light (1211) into polarized light engine light (1212), the first polarizer (1241) being a reflective polarizer,wherein the housing (1100) comprises a housing part (1110) being visible from the space (3000), and being arranged to receive the polarized light engine light (1212),wherein the housing part (1110) comprises a second polarizer (1111) and an additional layer (1112) downstream of the second polarizer (1111), andwherein the luminaire (1000) has one of a first configuration and a second configuration:in the first configuration, the second polarizer (1111) is a reflective polarizer being reflective for the polarized light engine light (1212), and the additional layer (1112) is a light-absorbing layer, the light-absorbing layer being a black layer, andin the second configuration, the second polarizer (1111) is a light-absorbing polarizer being transmissive for the polarized light engine light (1212), and the additional layer (1112) is a reflective layer being reflective for the polarized light engine light (1212).
2. The luminaire (1000) according to claim 1, wherein the second configuration applies, and wherein the reflective layer is specularly reflective for the polarized light source light (1212), or wherein the reflective layer is polarization-maintaining diffusely reflective for the polarized light source light (1212).
3. The luminaire (1000) according to any one of the preceding claims, wherein the second polarizer (1111) is separated from the first polarizer (1241) by a minimum separation distance of at least 1 centimeter.2024PF80280144. The luminaire (1000) according to any one of the preceding claims, wherein the light engine (1200) comprises a light mixing chamber (1230), the light source (1210) being provided in the light mixing chamber (1230), and the first polarizer (1241) being at least part of a chamber light exit window (1240) of the light mixing chamber (1230), and wherein one or more inner surfaces (1250) of the light mixing chamber (1230) comprise a reflector.
5. The luminaire (1000) according to claim 4, wherein the reflector is a diffuse reflector.
6. The luminaire (1000) according to claim 4, wherein the reflector is a specular reflector, and wherein the luminaire (1000) further comprises a quarter- wave plate (1260) being arranged at a side of the specular reflector that faces the light source (1210).
7. The luminaire (1000) according to any one of the preceding claims, wherein the housing part (1110) is further arranged to reflect the polarized light source light (1212) towards a luminaire light exit window of the luminaire (1000).
8. The luminaire (1000) according to claim 7, wherein the luminaire light exit window is transparent.
9. The luminaire (1000) according to claim 7, wherein the luminaire light exit window comprises a depolarizer for at least partly depolarizing the polarized light engine light (1212) upon passing through the luminaire light exit window.
10. The luminaire (1000) according to any one of the preceding claims, wherein the light source (1210) is a solid-state light source that comprises a LED filament.
11. The luminaire (1000) according to any one of the preceding claims, wherein the light engine (1200) is arranged in the housing (1100).
12. The luminaire (1000) according to any one of the preceding claims, wherein the luminaire (1000) is an outdoor luminaire.2024PF802801513. The luminaire (1000) according to any one of the preceding claims, wherein the light engine (1200) is a lamp (1210) having a base, wherein the luminaire (1000) further comprises a socket (1220), and wherein the base is arranged to mechanically and electrically connect the lamp (1210) in the socket (1220).
14. The luminaire (1000) according to any one of the preceding claims, wherein the light source (1210) is arranged to emit first unpolarized light source light (1211a) in a first angular range and second unpolarized light source light (1211b) in a second angular range, the first angular range and the second angular range being non-overlapping angular ranges, wherein the first polarizer (1241) is configured to polarize the first unpolarized light source light (1211a) into polarized light engine light (1212), and wherein the second unpolarized light source light (1211b) is comprised in the luminaire light (2000).