Freeform lens with convex outer surface and a convex-concave inner surface

Abstract

The invention provides an optical element arrangement (2000) comprising a first lens array (500); wherein the first lens array (500) comprises u*v lens arrangements (4000), wherein u ≥ 1 and v ≥ 1; wherein for each lens arrangement (4000) applies: (A) the lens arrangement (4000) comprises a light transparent material having a lens arrangement first face (4010) and a lens arrangement second face (4020); (B) the lens arrangement second face (4020) is configured convex and comprises a lens arrangement apex (4021); (C) the lens arrangement (4000) comprises a lens arrangement center axis (AL) configured perpendicular to and intersecting the lens arrangement apex (4021) of the lens arrangement second face (4020); wherein the lens arrangement (4000) has a maximum circular equivalent lens outer diameter DL in a plane perpendicular to the lens arrangement center axis (AL); (D) the lens arrangement first face (4010) comprises a central cavity (4100) configured extending towards the lens arrangement apex (4021) over part of the lens arrangement height (HL); wherein the central cavity (4100) comprises a cavity wall (4200); (E) in at least one central axis parallel cross-sectional view of the central cavity (4100), parallel to the lens arrangement center axis (AL), the cavity wall (4200) comprises k cavity wall first sections (4210), wherein k ≥ 3; wherein the k cavity wall first sections (4210) are alternatingly configured convex and concave; and (F) in at least one central axis perpendicular cross-sectional view of the central cavity (4100), perpendicular to the lens arrangement center axis (AL), the cavity wall (4200) comprises n cavity wall second sections (4220), wherein n ≥ 6; wherein the n cavity wall second sections (4220) are alternatingly configured convex and concave.

Description

[0001] 2024PF80273

[0002] 1

[0003] Freeform lens with convex outer surface and a convex-concave inner surface

[0004] FIELD OF THE INVENTION

[0005] The invention relates to an optical element arrangement. The invention further relates to a light generating system. Further yet, the invention relates to a lighting device comprising the light generating system.

[0006] BACKGROUND OF THE INVENTION

[0007] Diffusers are known in the art. For instance, EP2765445B1 describes a lens for an LED unit having one or more LEDs for distributing the light generated by the LED, comprising a light incidence side and a light emergence side relative to the LED, characterized in that the light emergence side comprises successively, starting from the optical axis (z) of the lens, a convex central region, a concave intermediate region, and a convex outer region.

[0008] US10330902B1 discloses a collimator lens having a solid monolithic structure that includes spaced-apart and longitudinally-extending side lobed segments laterally disposed around a central core section.

[0009] US20180135831A1 discloses beam forming optics having non-circular peripheral shapes.

[0010] SUMMARY OF THE INVENTION

[0011] Optical elements providing beam shaping are well-known and much used in lighting devices. Especially freeform lenses may be used, wherein the shape of the lens may determine the shape (and / or intensity profile) of a beam of light transmitted through the lens. Due to improvements in modelling software and production techniques, freeform lenses with intricate designs and tailored light distributions may be produced. Yet, typically, beamshaping optical elements (such as freeform lenses) may have a convex outer surface, wherein the convex outer surface may fall off at the sides of the lens (i.e. when viewing a crosssection of the lens parallel to an optical axis, an absolute slope of the outer surface may increase (at an increasing rate) towards the sides of the lens) with a degree depending on the desired cut-off angle of the transmitted beam of light. For outdoor lighting (e.g. road 2024PF80273

[0012] 2 lighting), the cut-off angle may typically be set to 70°-80°, and the degree with which the convex outer surface falls off at the sides of the lens may be relatively small. Further, for outdoor lighting, the optical element may not be directly visible, or may be located too high up for details to be distinguished, such that the shape of the optical element may not be as important. Yet, for indoor lighting applications, a more decorative optical element is desired, as the optical element may be viewed more often and in more detail. However, for indoor lighting applications, the cut-off angle is typically lower (60°-65°), such that the degree with which the convex outer surface falls off at the sides of the lens may be relatively large. This may require optical elements to have almost vertical sides, which may provide a busy appearance to a lighting device when several optical elements are placed (in an array) in e.g. a luminaire. Hence, there is a desire for optical elements providing beam shaping and having a more decorative appearance. Hence, it is an aspect of the invention to provide an alternative optical element, which preferably further at least partly obviates one or more of abovedescribed drawbacks. The present invention may have as object to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. The invention is set out in the appended set of claims.

[0013] According to a first aspect, the invention provides an optical element arrangement comprising a first lens array. The first lens array may comprise u*v lens arrangements. In embodiments, u > 1 and v > 1. For each lens arrangement may apply that the lens arrangement may comprise a light transparent material having a lens arrangement first face and a lens arrangement second face. Further, for each lens arrangement may apply that the lens arrangement second face may be configured convex and may comprise a lens arrangement apex. Additionally, (each of) the lens arrangement(s) may comprise a (respective) lens arrangement center axis (AL) configured perpendicular to and intersecting the lens arrangement apex of the lens arrangement second face. The lens arrangement may have a (maximum) lens arrangement height (HL) along the lens arrangement center axis (AL). Further, the lens arrangement may have a maximum circular equivalent lens outer diameter DL in a plane perpendicular to the lens arrangement center axis (AL). In embodiments, HL < 0.5*DL may apply. Further, the lens arrangement first face may comprise a central cavity configured extending towards the lens arrangement apex over part of the lens arrangement height (HL). In embodiments, the central cavity may be configured to host a source of light. Further, the central cavity may comprise a cavity wall. In at least one central axis parallel cross-sectional view of the central cavity, parallel to the lens arrangement center axis (AL), the cavity wall may comprise k cavity wall first sections. In embodiments, k > 3 may apply. 2024PF80273

[0014] 3

[0015] Further, the k cavity wall first sections may be altematingly configured convex and concave. Additionally or alternatively, in at least one central axis perpendicular cross-sectional view of the central cavity, perpendicular to the lens arrangement center axis (AL) (and near the lens arrangement first face), the cavity wall may comprise n cavity wall second sections. In embodiments, n > 6 may apply. Further, the n cavity wall second sections may be altematingly configured convex and concave. Hence, in specific embodiments, the invention provides an optical element arrangement comprising a first lens array; wherein the first lens array comprises u*v lens arrangements, wherein u > 1 and v > 1; wherein for each lens arrangement applies: (A) the lens arrangement comprises a light transparent material having a lens arrangement first face and a lens arrangement second face; (B) the lens arrangement second face is configured convex and comprises a lens arrangement apex; (C) the lens arrangement comprises a lens arrangement center axis (AL) configured perpendicular to and intersecting the lens arrangement apex of the lens arrangement second face; wherein the lens arrangement has a lens arrangement height (HL) along the lens arrangement center axis (AL); (D) the lens arrangement first face comprises a central cavity configured extending towards the lens arrangement apex over part of the lens arrangement height (HL); wherein the central cavity comprises a cavity wall; (E) in at least one central axis parallel cross-sectional view of the central cavity, parallel to the lens arrangement center axis (AL), the cavity wall comprises k cavity wall first sections, wherein k > 3; wherein the k cavity wall first sections are altematingly configured convex and concave; and (F) in at least one central axis perpendicular cross-sectional view of the central cavity, perpendicular to the lens arrangement center axis (AL), the cavity wall comprises n cavity wall second sections, wherein n > 6; wherein the n cavity wall second sections are altematingly configured convex and concave. Such an optical element arrangement may facilitate that the lens arrangements may be relatively flat, yet may provide suitable beam-shaping properties (when combined with a source of light). Hence, such an optical element arrangement may be especially decorative and / or provide a more even and softer appearance of the first lens array. Further, such an optical element arrangement may, depending on the number and properties of the cavity wall first sections and cavity wall second sections, be configured to provide a beam of light (in combination with a source of light) having at least 2 peaks, thereby allowing tuning of the beam of light.

[0016] The optical element arrangement may comprise a first lens array. The first lens array may be regular, random, or quasi random. Especially, in embodiments, the first lens array may be a regular 2D array. However, other arrays, like a phyllotaxis tessellation or a 2024PF80273

[0017] 4 sunflower tessellation, may also be possible. The term “tessellation” may herein especially refer to a pattern of (repeated) shapes, e.g. polygons, that fit together closely without gaps or overlapping. In embodiments, the tessellation may comprise a translation tessellation of the entrance shape. The term “translation tessellation” may herein especially refer to a tessellation wherein the tessellated shape, such as the polygon, may be moved without rotation or mirroring thereof. Yet, especially, the first lens array may be a regular array. In embodiments, the array is a (regular) u*v array, wherein u and v are each individually selected from the range of > 1 (see also below). Hence, in embodiments the first lens array may have one or two constant pitches. The first lens array may especially have a first pitch in a first direction, and a second pitch in a second, orthogonal, direction.

[0018] As indicated above, the first lens array may be a (regular) u*v array. Further, the first lens array may be an array of lens arrangements. Hence, the first lens array may comprise u*v lens arrangements. In embodiments, u may be selected from the range of > 1, such as from the range of > 2, especially from the range of > 3. Additionally or alternatively, u may be selected from the range of < 20, such as from the range of < 18, especially from the range of < 16. Further, in embodiments, v may be (individually) selected from the range of > 1, such as from the range of > 2, especially from the range of > 3. Additionally or alternatively, v may be (individually) selected from the range of < 20, such as from the range of < 18, especially from the range of < 16. Hence, in embodiments, u =1 and v = 1 may apply, such that the first lens array may comprise (such as consist of) a single lens arrangement. Alternatively, in embodiments, u + v > 3 may apply, such as u + v > 6, especially u + v > 8, like u + v > 10. Additionally or alternatively, in embodiments, u + v < 40 may apply, such as u + v < 36, especially u + v < 32.

[0019] In embodiments, the lens arrangements may be configured in physical contact (with each other) in the first lens array. Especially, the lens arrangement may be configured in physical contact (with each other) in the first lens array via their respective lens arrangement second faces. That is, the lens arrangement second faces of adjacent lens arrangements in the first lens array may be configured in physical contact with each other. Hence, in specific embodiments, u + v > 3 may apply, and the lens arrangement second faces of adjacent lens arrangements in the first lens array may be configured in physical contact with each other. Configuring the lens arrangements in physical contact with each other in the first lens array may facilitate producing the first lens array as a single component. Further, configuring the lens arrangements in physical contact with each other in the first lens array 2024PF80273

[0020] 5 may provide an even, uninterrupted, appearance of the optical element arrangement, thereby providing an optical element arrangement having a more calming and decorative effect.

[0021] Alternatively, in embodiments, the lens arrangements may be configured physically separated in the first lens array. Especially, the lens arrangements may be configured physically separated in the first lens array by an edge-to-edge distance selected from the range of > 1 mm, such as from the range of > 2 mm, especially from the range of > 3 mm. Additionally or alternatively, the lens arrangements may be configured physically separated in the first lens array by an edge-to-edge distance selected from the range of < 100 mm, such as from the range of < 80 mm, especially from the range of < 60 mm. In such embodiments, the optical element arrangement may comprise a lens arrangement holder, wherein the lens arrangement holder may be configured to host the u*v lens arrangements and to physically separate the u*v lens arrangements (from each other). In embodiments, the lens arrangement holder may comprise a substrate, onto which the lens arrangements may be mounted. Said substrate may be a planar substrate, yet may in embodiments be a curved substrate. Further, said substrate may comprise one or more lens arrangement depressions, such as especially u*v lens arrangement depressions. In embodiments, (each of) the lens arrangements may be configured in (one of) the lens arrangement depressions. Further, in embodiments, the (internal) side walls of the one or more lens arrangement depressions may be configured reflective. Hence, in embodiments, each lens arrangement may be configured in a reflective cup in the optical element arrangement. Configuring the lens arrangements in a reflective cup may facilitate steering (refracted) light emitted through the lens arrangement into a desired direction, thereby improving the efficiency and intensity of a light generating system comprising the optical element arrangement.

[0022] Each lens arrangement (in the first lens array) may comprise a light transparent material. Herein, the term “light transparent” material indicates the material may be (specular) transmissive, such as transparent, for one or more wavelengths selected from the range of 190-1500 nm, such as from the range of 200-1000 nm, especially from the range of 380-780 nm (i.e. visible light). In embodiments, the light transparent material may comprise one or more materials selected from the group comprising glass, polycarbonate (PC), polyethylene (PE), polystyrene (PS), polypropylene (PP), polyethylene terephthalate (PET), (clear) polyvinyl chloride (PVC), cyclic olefin copolymers (COC), fluorinated ethylene propylene (FEP), styrene methyl methacrylate (SMMA), polysiloxanes, poly(methyl methacrylate) (PMMA), and fused silica. Further, the optical element arrangement, such as especially the light transparent material, may in embodiments have an absorption length 2024PF80273

[0023] 6 and / or a scatter length of at least 5 times, such as at least 10 times, especially at least 50 times, like at least 100 times, a thickness of the optical element arrangement. The absorption length may be defined as the length over which the intensity of the light along a propagation direction due to absorption drops with 1 / e. Likewise, the scatter length may be defined as the length along a propagation direction along which light is lost due to scattering and drops thereby with a factor 1 / e. Here, the (absorption and / or scatter) length may especially refer to the distance between the cavity wall and the lens arrangement second face of the lens arrangement, with the light transparent material configured between the lens arrangement first face, cavity wall, and lens arrangement second face.

[0024] In other embodiments, the light transparent material may be light scattering, like hosting a light scattering material. The light scattering material may especially be configured embedded in the light transparent material. Further, the light scattering material may be configured to scatter (or “diffuse”) light incident on the light scattering material. In specific embodiments, the light scattering material may comprise light scattering particles, such as e.g. at least one of BaSCU, SiCh, A12O3 and TiCh particles. Hence, the light transparent material may be light scattering (e.g. the light transparent material comprise light scattering particles). In specific embodiments, the light transparent material may be a light scattering light transparent material. The light scattering light transparent material may be configured such, that for a planar (or “flat”) body of the light scattering light transparent material with an (average) thickness of 5 mm may apply that a parallel beam incident on the planar body from a direction parallel to the surface normal of the planar body may be transmitted through the planar body, wherein the transmitted beam may have a full width at half maximum (in an angular intensity distribution of the transmitted beam) of at most 40°, such as at most 30°, especially at most 20°. That is, in specific embodiments, the light transparent material may be light scattering, wherein a flat body consisting of the light transparent material and having a thickness of 5 mm may increase a full width at half maximum of an incident parallel beam by at most 40°, such as at most 30°, especially at most 20° (upon transmission through the flat body), and wherein the incident parallel beam may be incident on the flat body from a direction perpendicular to the flat body. In other embodiments, however, the light transparent material may essentially be not scattering, such that a flat body consisting of such light transparent material and having a thickness of 5 mm may essentially not increase a full width at half maximum of an incident parallel beam, such as an increase by at most 10°, such as at most 5°, especially at most 2° (upon transmission 2024PF80273

[0025] 7 through the flat body), and wherein the incident parallel beam may be incident on the flat body from a direction perpendicular to the flat body.

[0026] The lens arrangement first face, cavity wall, and lens arrangement second face may define the boundaries of the light transparent material (of the lens arrangement). That is, the light transparent material may have a lens arrangement first face and a lens arrangement second face. At least part of the lens arrangement first face may be configured planar. Further, the lens arrangement second face may be configured convex. Especially, the lens arrangement second face may comprise a lens arrangement apex. In embodiments, the lens arrangement second face may (in every direction) have a derivative of (essentially) zero at the lens arrangement apex, wherein the (absolute) derivative (of the lens arrangement second face) may increase in every direction around the lens arrangement apex. The lens arrangement first face may be configured (directly) physically coupled with, such as in physical contact with, the lens arrangement second face. Especially, the lens arrangement first face may be (at least partially) configured opposite the lens arrangement apex, and in physical contact with the lens arrangement second face.

[0027] The lens arrangement may comprise a lens arrangement center axis (AL) (“center axis (AL)”) configured perpendicular to and intersecting the lens arrangement apex. The lens arrangement center axis (AL) may in embodiments intersect a geometrical center of the lens arrangement first face. Further, the lens arrangement first face may be configured in physical contact with the lens arrangement second face over an angle (cp) of > 300°, such as > 330°, especially > 350°, including (essentially) 360°, around the lens arrangement center axis (AL). Further, the at least part of the lens arrangement first face configured planar may be configured planar in a plane perpendicular to the lens arrangement center axis (AL). In embodiments, the lens arrangement first face may further be at least partially configured at an angle with respect to the lens arrangement center axis (AL). Especially, the lens arrangement first face may comprise one or more first face slanted (and / or curved) sections, wherein the one or more first face slanted (and / or curved) sections may be configured at an angle with the lens arrangement center axis (AL). The lens arrangement first face may especially be configured in physical contact with the lens arrangement second face via the one or more first face slanted (and / or curved) sections. That is, at the point of physical contact between the lens arrangement first face and lens arrangement second face, the lens arrangement first face may slant (and / or curve) towards the lens arrangement second face. In embodiments, the lens arrangement first face may slant (and / or curve) in opposite directions at opposite sides around the lens arrangement center axis (AL). Hence, in specific embodiments, the lens 2024PF80273

[0028] 8 arrangement first face may be configured in physical contact with the lens arrangement second face over an angle (cp) of 360° around the lens arrangement center axis (AL). Configuring the lens arrangement first face in physical contact with the lens arrangement second face over a 360° angle around the lens arrangement center axis (AL) may facilitate that the lens arrangement (especially the cavity) may (essentially) fully surround (and / or enclose) at least part of a source of light placed in the cavity.

[0029] (Each of) the lens arrangement(s) (in the first lens array) may have a maximum circular equivalent lens outer diameter DL in a plane perpendicular to the lens arrangement center axis (AL). The equivalent circular diameter (or ECD) of an (irregularly shaped) two-dimensional shape is the diameter of a circle of equivalent area. For instance, the equivalent circular diameter of a square with side a is 2a / SQRT(7t). For a circle, the diameter D is the same as the equivalent circular diameter D. Would a circle in an xy-plane with a diameter D be distorted to any other shape (in the xy-plane), without changing the area size, then the equivalent circular diameter of that shape would be D. The maximum circular equivalent lens outer diameter DL may especially be determined at the point along the lens arrangement center axis (AL) where, when viewing an outer perimeter of the lens arrangement in a cross-sectional plane perpendicular to the lens arrangement center axis (AL) while moving along the lens arrangement center axis (AL), said outer perimeter may encompass the largest surface area (in the cross-sectional plane). Further, in embodiments, the maximum circular equivalent lens outer diameter DL may be selected from the range of > 10 mm, such as from the range of > 15 mm, especially from the range of > 20 mm. Additionally or alternatively, the maximum circular equivalent lens outer diameter DL may be selected from the range of < 150 mm, such as from the range of < 100 mm, especially from the range of < 50 mm.

[0030] Further, (each of) the lens arrangement(s) (in the first lens array) may have a (maximum) lens arrangement height HL along (the direction of) the lens arrangement center axis (AL). In embodiments, the lens arrangement height HL may especially be the distance between the lens arrangement apex and (a geometrical center of) the lens arrangement first face (in a plane perpendicular to the lens arrangement center axis (AL)). The lens arrangement height HL may be selected from the range of > 5 mm, such as from the range of > 10 mm, especially from the range of > 15 mm. Additionally or alternatively, the lens arrangement height HL may be selected from the range of < 100 mm, such as from the range of < 50 mm, especially from the range of < 25 mm. Additionally or alternatively, in embodiments, HL < DL may apply, such as HL < 0.75*DL, especially HL < 0.5*DL. Further, in 2024PF80273

[0031] 9 embodiments, HL < 0.4*DL may apply, such as HL < 0.37*DL, especially HL < 0.3 *DL. Hence, in specific embodiments, HL < 0.37*DL (may apply). A lens arrangement having a relatively short and wide appearance may be viewed as more calming by a user. Especially, an optical element arrangement comprising a first lens array of lens arrangements having HL < 0.37*DL may have less height deviation across the first lens array, thereby providing a more even and decorative appearance. Yet, in embodiments, HL > 0.1 *DL may apply, such as HL > 0.15*DL, especially HL > 0.2*DL.

[0032] The lens arrangement may have a lens arrangement shape in a cross-section perpendicular to the lens arrangement center axis (AL). Especially, an outer perimeter of the lens arrangement may have the lens arrangement shape in a cross-section perpendicular to the lens arrangement center axis (AL). The lens arrangement shape may be determined at the point (along the lens arrangement height HL) at which the lens arrangement has an equivalent circular diameter equal to DL. That is, the lens arrangement shape may be determined at the point at which the lens arrangement is at its widest (and / or longest). In embodiments, the lens arrangement shape may be selected from the group comprising a circle, an ellipse, and a regular (simple) n-gonal, wherein 2 < n < 24. Hence, in specific embodiments, the lens arrangement may have a circular shape in a cross-section perpendicular to the lens arrangement center axis (AL) (at the point of DL). Alternatively, the lens arrangement may have an ellipsoidal shape in a cross-section perpendicular to the lens arrangement center axis (AL) (at the point of DL). Alternatively, the lens arrangement may have a square shape in a cross-section perpendicular to the lens arrangement center axis (AL) (at the point of DL).

[0033] As indicated above, the lens arrangement second face may be configured (overall) convex (when viewed from an outside of the lens arrangement). That is, moving from a point of physical contact between the lens arrangement first face and lens arrangement second face (along an outside edge of the lens arrangement) towards the center of the lens arrangement, the lens arrangement second face may curve away from the lens arrangement first face (such that the lens arrangement may be highest at the lens arrangement apex). In embodiments, the lens arrangement second face may comprise one or more deviations on a small (e.g. < 2 mm, such as < 1 mm, especially < 0.5 mm) scale, wherein the one or more deviations may comprise flat or concave sections. Yet, on a larger (e.g. > 2 mm, such as > 5 mm, especially > 7 mm) scale, the lens arrangement second face may be configured convex (when viewed from an outside of the lens arrangement). The lens arrangement second face may have a radius of curvature. Especially, the lens arrangement second face may have an average radius of mean curvature Ri. The term “radius of mean curvature” is known to the 2024PF80273

[0034] 10 person skilled in the art, wherein the radius of mean curvature may be determined by: (i) virtually drawing a normal line to the lens arrangement second face at a single point on the lens arrangement second face; (ii) while rotating about the normal line, virtually drawing a plurality of z planes parallel to and intersecting the normal line; (iii) determining the (signed) radius of curvature of the lens arrangement second face in each of the z planes, and (iv) averaging the (signed) radius of curvature over z. In embodiments, the radius of mean curvature may be determined for every point along the lens arrangement second face, after which the obtained radii of mean curvature may be averaged to provide the average radius of mean curvature Ri. In embodiments, Ri may be selected from the range of > 5 mm, such as from the range of > 10 mm, especially from the range of > 15 mm. Additionally or alternatively, Ri may be selected from the range of < 75 mm, such as from the range of < 50 mm, especially from the range of < 40 mm. Further, Ri may be selected from the range of Ri > 0.3*DL, such as Ri > 0.5*DL, especially Ri > 0.65*DL. Additionally or alternatively, Ri may be selected from the range of Ri < 10*DL, such as Ri < 8*DL, especially Ri < 6*DL. Hence, in specific embodiments, the lens arrangement second face may have an average radius of mean curvature Ri; wherein Ri > 0.5*DL (may apply). Such an average radius of mean curvature may facilitate that the lens arrangement second face may have a relatively shallow curvature, thereby decreasing the height deviation across the optical element arrangement.

[0035] In embodiments, the lens arrangement second face may further have a minimum radius of curvature Rmin. That is, in embodiments, the lens arrangement second face may be aspherical, wherein the lens arrangement second face may have a plurality of radii of curvature, and wherein the smallest radius of curvature may be Rmin. In embodiments, Rmin may be selected from the range of > 5 mm, such as from the range of > 10 mm, especially from the range of > 15 mm. Additionally or alternatively, Rmin may be selected from the range of < 75 mm, such as from the range of < 50 mm, especially from the range of < 40 mm. Further, Rmin may be selected from the range of Rmin > 0.3 *DL, such as Rmin > 0.5*DL, especially Rmin > 0.65 *DL. Additionally or alternatively, Rmin may be selected from the range of Rmin < 10*DL, such as Rmin < 8*DL, especially Rmin < 6*DL. Hence, in specific embodiments, the lens arrangement may have a maximum circular equivalent lens outer diameter DL in a plane perpendicular to the lens arrangement center axis (AL); wherein the lens arrangement second face may have a minimum radius of curvature Rmin; wherein Rmin > 0.5*DL (may apply). A minimum radius of curvature Rmin selected from the range of > 0.5*DL may facilitate that, would the lens arrangement second face approximate a halfsphere, the height of the lens arrangement second face (along the lens arrangement center 2024PF80273

[0036] 11 axis (AL)) may not exceed 0.5*DL, thereby providing a lens arrangement having a relatively shallow curvature.

[0037] The lens arrangement second face may thus have a plurality of radii of curvature Ri (with a minimum radius of curvature Rmin). Especially, the lens arrangement second face may be (configured) aspherical. In such embodiments, the (aspherical) lens arrangement second face may have a shape in a plane parallel to the lens arrangement center axis (AL) (and intersecting the lens arrangement apex) selected from the group comprising a hyperbolic shape, a parabolic shape, a semi-elliptical shape, a polynomial shape, and an irregular curved shape. Further, in embodiments, the lens arrangement second face may be configured aspherical, wherein the lens arrangement second face may have the minimum radius of curvature Rmin at a first location (or spot) on the lens arrangement second face, and wherein the radius of curvature of the lens arrangement second face may increase with increasing distance from said first location. Alternatively, the lens arrangement second face may have a constant radius of curvature RL (across the lens arrangement second face). Especially, in embodiments, the lens arrangement second face may be configured spherical. In such embodiments, the lens arrangement second face may define at least part of a sphere. Especially, in embodiments, the lens arrangement second face may define a half-sphere (in a cross-section parallel to the lens arrangement center axis (AL) and intersecting the lens arrangement apex). Alternatively, the lens arrangement second face may define a spherical cap (or “spherical dome”). The lens arrangement second face may thus be (configured) spherical, wherein at every point across the lens arrangement second face, the lens arrangement second face may have the same radius of curvature RL. In embodiments, RL > Rmin, such as especially RL = Rmin. Further, in embodiments, RL may be selected from the range of > 5 mm, such as from the range of > 10 mm, especially from the range of > 15 mm. Additionally or alternatively, RL may be selected from the range of < 75 mm, such as from the range of < 50 mm, especially from the range of < 40 mm. Further, RL may be selected from the range of RL > 0.3*DL, such as RL > 0.5*DL, especially RL > 0.65*DL. Additionally or alternatively, RL may be selected from the range of RL < 10*DL, such as RL < 8*DL, especially RL < 6*DL. Hence, in specific embodiments, the lens arrangement second face may define at least part of a sphere. A lens arrangement second face defining at least part of a sphere may have a more decorative and calm appearance, as a spherical cap may be perceived as more pleasant to look at than an ellipsoidal cap by a user.

[0038] In embodiments, the lens arrangement second face may be configured symmetric. Especially, the lens arrangement may comprise a second face mirror plane, 2024PF80273

[0039] 12 wherein the second face mirror plane may be configured parallel to and intersecting the lens arrangement center axis (AL), and wherein the lens arrangement second face may be configured (mirror-)symmetrical about the second face mirror plane. Further, in embodiments, the lens arrangement may comprise a plurality of second face mirror planes, wherein each of the second face mirror planes may be configured parallel to and intersecting the lens arrangement center axis (AL), and wherein the lens arrangement second face may be configured (mirror-)symmetrical about each of the second face mirror planes. Hence, the lens arrangement second face may have rotational symmetry of order > 2, such as rotational symmetry of order > 4, especially rotational symmetry of order > 6 (about the lens arrangement center axis (AL)). In specific embodiments, the lens arrangement second face may be rotationally symmetric (at every angle about the lens arrangement center axis (AL)). Alternatively, the lens arrangement second face may have rotational symmetry of order < 16, such as rotational symmetry of order < 12, especially rotational symmetry of order < 8 (about the lens arrangement center axis (AL)).

[0040] In embodiments, (each of) the lens arrangement(s) (in the first lens array) may comprise a central cavity. Especially, the lens arrangement first face may comprise the central cavity. The central cavity may be configured extending (from the lens arrangement first face) towards the lens arrangement apex. Further, the central cavity may be configured centered in the lens arrangement first face. That is, in a cross-section perpendicular to the lens arrangement center axis (AL), a geometrical center of the central cavity may overlap with a geometrical center of the lens arrangement first face. Further, a geometrical center of the central cavity (in a cross-section perpendicular to the lens arrangement center axis (AL) may overlap with the lens arrangement center axis (AL). In embodiments, the central cavity may be configured to host at least part of a source of light (see also below). Especially, the central cavity may be configured to host at least part of a source of light, such that said source of light may emit light into the central cavity (and towards the lens arrangement second face). Alternatively, the central cavity may not host a source of light, yet may be configured in a light receiving relationship with a source of light. Especially, the cavity wall may be configured to receive light from (or emitted by) a source of light, wherein the source of light may be configured upstream of the cavity wall (and outside of the central cavity). Yet, in specific embodiments, the source of light may be at least partly, such as completely, configured in the central cavity. The terms “upstream” and “downstream” relate to an arrangement of items or features relative to the propagation of the light from a light generating means (here the especially the source of light), wherein relative to a first position 2024PF80273

[0041] 13 within a beam of light from the light generating means, a second position in the beam of light closer to the light generating means is “upstream”, and a third position within the beam of light further away from the light generating means is “downstream”.

[0042] As indicated above, the central cavity may be configured extending (from the lens arrangement first face) towards the lens arrangement apex. Especially, the central cavity may have a cavity height (He) along the lens arrangement center axis (AL) (and starting from (a point of contact with) the lens arrangement first face). In embodiments, the cavity height (He) may be selected from the range of > 0.15*HL, such as from the range of > 0.3 *HL, especially from the range of > 0.4*HL. Additionally or alternatively, the cavity height (He) may be selected from the range of < 0.98*HL, such as from the range of < 0.95*HL, especially from the range of < 0.9*HL. Further, in embodiments, 0.15*HL < He < 0.98*HL (may apply), such as 0.3*HL < He < 0.95*HL, especially 0.4*HL < He < 0.9*HL. Hence, in specific embodiments, the central cavity may have a cavity height (He) along the lens arrangement center axis (AL), wherein 0.3*HL < He < 0.95*HL; and wherein HL < 0.5*DL. Such a cavity height (He) may facilitate that the lens arrangement may comprise a layer of light transparent material between the cavity and the lens arrangement second face (such as especially the lens arrangement apex) having a thickness of at least 0.05*HL, thereby improving the stability and durability of the lens arrangement. Further, the light transparent material between the (top of the) cavity and the light arrangement apex may guide and / or shape light transmitted through the lens arrangement, thereby providing a beam of light having a desired angular radiant intensity distribution.

[0043] The central cavity may further have a maximum circular equivalent cavity outer diameter De in a plane perpendicular to the lens arrangement center axis (AL). The maximum circular equivalent cavity outer diameter De may especially be determined at the point along the lens arrangement center axis (AL) where, when viewing an outer perimeter of the cavity in a cross-sectional plane perpendicular to the lens arrangement center axis (AL) while moving along the lens arrangement center axis (AL), said outer perimeter may encompass the largest surface area (in the cross-sectional plane). In embodiments, the maximum circular equivalent cavity outer diameter De may be selected from the range of > 5 mm, such as from the range of > 7.5 mm, especially from the range of > 10 mm. Additionally or alternatively, the maximum circular equivalent cavity outer diameter De may be selected from the range of < 100 mm, such as from the range of < 65 mm, especially from the range of < 35 mm. Further, the maximum circular equivalent cavity outer diameter De may be selected from the range of > 0.25 *DL, such as from the range of > 0.3 *DL, especially from 2024PF80273

[0044] 14 the range of > 0.5*DL. Additionally or alternatively, the maximum circular equivalent cavity outer diameter De may be selected from the range of < 0.9*DL, such as from the range of < 0.8*DL, especially from the range of < 0.75*DL.

[0045] In embodiments, the central cavity may comprise a cavity wall. The cavity wall may, together with the lens arrangement first face and the lens arrangement second face, enclose the light transparent material. Further, the cavity wall may be at least partially, such as fully, enclosed (and / or surrounded) by the lens arrangement second face. The cavity wall may comprise k cavity wall first sections in at least one central axis parallel cross-sectional view (or “central-axis-parallel cross-sectional view”), wherein the central axis parallel cross- sectional view may be a cross-sectional view (taken) parallel to (and intersecting) the lens arrangement center axis (AL). In embodiments, k > 1 may apply, such as k > 3, especially k > 5. Additionally or alternatively, k < 11 may apply, such as k < 9, especially k < 7. Especially, k may be an odd number. Hence, in specific embodiments, k < 9 (may apply). A cavity wall having < 9 cavity wall first sections may facilitate that the lens arrangement may be relatively easy to produce, compared to a lens arrangement comprising > 9 cavity wall first sections. Further, light emitted into the central cavity and transmitted through the lens arrangement may scatter and / or be refracted in an undesired direction at a point of transition between a first cavity wall first section and a second cavity wall first section. Hence, a cavity wall comprising < 9 cavity wall first sections may limit the number of transitions, thereby improving the efficiency of the lens arrangement.

[0046] In embodiments, the cavity wall first sections may be altematingly configured convex and concave (with respect to a geometrical center of the central cavity). That is, the cavity wall first sections may comprise at least one convex cavity wall first section and at least one concave cavity wall first section, wherein each convex cavity wall first section may be configured in physical contact with at least one concave cavity wall first section (and be physically separated from all other convex cavity wall first sections), and each concave cavity wall first section may be configured in physical contact with at least one convex cavity wall first section (and be physically separated from all other concave cavity wall first sections). In embodiments, the inflection point between a convex cavity wall first section and a concave cavity wall first section may be defined as the point at which the curvature changes sign, as is known to the person skilled in the art. Further, in embodiments, the k cavity wall first sections may especially comprise at least two convex cavity wall first sections and at least one concave cavity wall first section (configured as convex-concave-convex). Hence, the k cavity wall first sections may comprise at least two, such as at least four, especially at 2024PF80273

[0047] 15 least six, convex cavity wall first sections. Additionally or alternatively, the k cavity wall first sections may comprise at most ten, such as at most eight, especially at most six, convex cavity wall first sections. Especially, the k cavity wall first sections may comprise an even number of convex cavity wall first sections (in the at least one central axis parallel cross- sectional view). Further, the k cavity wall first sections may comprise at least one, such as at least three, especially at least five, concave cavity wall first sections. Additionally or alternatively, the k cavity wall first sections may comprise at most nine, such as at most seven, especially at most five, concave cavity wall first sections. Hence, the k cavity wall first sections may comprise an odd number of concave cavity wall first sections (in the at least one central axis parallel cross-sectional view). Further, as indicated above, k may be an odd number. In the at least one central axis parallel cross-sectional view, a concave cavity wall first section may be configured as the middle (or center) of the k cavity wall first sections (and closest to the lens arrangement apex), wherein the lens arrangement center axis (AL) may intersect said concave cavity wall first section, and wherein said concave cavity wall first section may be configured in physical contact with two convex cavity wall first sections (configured on opposite sides of said concave cavity wall first section).

[0048] Each of the (at least two) convex cavity wall first sections may have a minimum primary first radius of curvature RI,L In embodiments, each of the convex cavity wall first sections may have a single radius of curvature, wherein said radius of curvature may be the minimum primary first radius of curvature Ri,i. Alternatively, each of the convex cavity wall first sections may have a plurality of radii of curvature, wherein the smallest of said radii of curvature may be the minimum primary first radius of curvature Ri,i. In embodiments, the minimum primary first radius of curvature Ri,i may (for each convex cavity wall first section individually) be selected from the range of > 2 mm, such as from the range of > 3 mm, especially from the range of > 4 mm. Additionally or alternatively, the minimum primary first radius of curvature Ri,i may (for each convex cavity wall first section individually) be selected from the range of < 120 mm, such as from the range of < 100 mm, especially from the range of < 80 mm. Further, the minimum primary first radius of curvature Ri,i may (for each convex cavity wall first section individually) be selected from the range of > 0.06*DL, such as from the range of > 0.1 *DL, especially from the range of > 0.15*DL. Additionally or alternatively, the minimum primary first radius of curvature Ri,i may (for each convex cavity wall first section individually) be selected from the range of < DL, such as from the range of < 0.8*DL, especially from the range of < 0.6*DL. 2024PF80273

[0049] 16

[0050] Further, (each of) the (at least one) concave cavity wall first section(s) may have a minimum secondary first radius of curvature RI,2. In embodiments, each of the concave cavity wall first sections may have a single radius of curvature, wherein said radius of curvature may be the minimum secondary first radius of curvature RI,2. Alternatively, each of the concave cavity wall first sections may have a plurality of radii of curvature, wherein the smallest of said radii of curvature may be the minimum secondary first radius of curvature RI,2. In embodiments, the minimum secondary first radius of curvature RI,2 may (for each concave cavity wall first section individually) be selected from the range of > 1 mm, such as from the range of > 2 mm, especially from the range of > 3 mm. Additionally or alternatively, the minimum secondary first radius of curvature RI,2 may (for each concave cavity wall first section individually) be selected from the range of < 20 mm, such as from the range of < 15 mm, especially from the range of < 10 mm. Further, the minimum secondary first radius of curvature RI,2 may (for each concave cavity wall first section individually) be selected from the range of > 0.03*DL, such as from the range of > 0.05*DL, especially from the range of > 0.07*DL. Additionally or alternatively, the minimum secondary first radius of curvature RI,2 may (for each concave cavity wall first section individually) be selected from the range of < 0.5*DL, such as from the range of < 0.4*DL, especially from the range of < 0.3 *DL. Further, in embodiments, RI,2 < Ri,i may apply, such as RI,2 < Ri,i, especially RI,2 < 0.5*Ri,i, like RI,2 < 0.2*Ri,i. Additionally or alternatively, RI,2 > 0.1*Ri,i may apply, such as RI,2 > 0.2*Ri,i, especially RI,2 > 0.3*Ri,i. Hence, in specific embodiments, the k cavity wall first sections may comprise at least two convex cavity wall first sections and at least one concave cavity wall first section; wherein the convex cavity wall first sections may have a minimum primary first radius of curvature Ri,i; wherein the concave cavity wall first section may have a minimum secondary first radius of curvature RI,2; wherein RI,2 < Ri,i. A lens arrangement wherein the concave cavity wall first section(s) may have a smaller radius of curvature than the convex cavity wall first sections may facilitate that light may be on average more diverged than converged (or collimated) upon transmission through the cavity wall first sections (from the central cavity). Further, a lens arrangement comprising a concave cavity wall first section in the center of the cavity wall (and closest to the lens arrangement apex), wherein said concave cavity wall first section may have a smaller radius of curvature than the (adjacent) convex cavity wall first sections, may provide the benefit that a relatively large part of the light emitted (from a direction of the lens arrangement first face) towards the lens arrangement apex may be refracted towards the 2024PF80273

[0051] 17 sides of the lens arrangement (i.e., away from the lens arrangement center axis (AL)), such that a beam of light with at least two peaks may be provided.

[0052] In embodiments, as indicated above, a concave cavity wall first section may be configured as the middle (or center) of the k cavity wall first sections. In embodiments wherein the k cavity wall first sections may comprise at least three concave cavity wall first sections (i.e., k > 5), said center concave cavity wall first section may in embodiments have a smaller minimum secondary first radius of curvature RI,2 than the other concave cavity wall first sections. Especially, the minimum secondary first radius of curvature RI,2 of said center concave cavity wall first section may be at least 2 times, such as at least 4 times, especially at least 8 times, smaller than the minimum secondary first radius of curvature RI,2 of the other concave cavity wall first sections. Additionally or alternatively, the minimum secondary first radius of curvature RI,2 of said center concave cavity wall first section may be at most 20 times, such as at most 15 times, especially at most 10 times, smaller than the minimum secondary first radius of curvature RI,2 of the other concave cavity wall first sections.

[0053] The cavity wall may have a cavity wall first curvature length Lei in the at least one central axis parallel cross-sectional view of the central cavity. Further, the (at least two) convex cavity wall first sections may have a (combined) primary first curvature length Lci,i along the cavity wall first curvature length Lei. That is, would the cavity wall comprise two convex cavity wall first sections, each of said convex cavity wall first sections may have a length of Lci,i / 2 along the cavity wall first curvature length Lei. In embodiments, the primary first curvature length Lci,i may be evenly divided over the convex cavity wall first sections, wherein each convex cavity wall first section may have the same length. Alternatively, the primary first curvature length Lci,i may be unevenly divided over the convex cavity wall first sections. Yet, especially, the convex cavity wall first sections may comprise one or more sets of two convex cavity wall first sections, wherein the convex cavity wall first sections in each set may have the same length along the cavity wall first curvature length Lei (and wherein the convex cavity wall first sections in each set may be configured opposite each other along the cavity wall). In embodiments, the (combined) primary first curvature length Lci,i may be selected from the range of > 0.3*Lci, such as from the range of > 0.4*Lci, especially from the range of > 0.5*Lci. Additionally or alternatively, the (combined) primary first curvature length Lci,i may be selected from the range of < 0.9*Lci, such as from the range of < 0.8*Lci, especially from the range of < 0.7*Lci. Further, in embodiments, 0.3*Lci < Lci,i < 0.9*Lci may apply, such as 0.4*Lci < Lci,i < 0.8*Lci, especially 0.5*Lci < Lci,i < 0.7*Lci. 2024PF80273

[0054] 18

[0055] Additionally or alternatively, the (at least one) concave cavity wall first section(s) may have a (combined) secondary first curvature length LCI,2 along the cavity wall first curvature length Lei. That is, would the cavity wall comprise one concave cavity wall first section, said concave cavity wall first section may have a length of LCI,2 along the cavity wall first curvature length Lei. In embodiments, the secondary first curvature length LCI,2 may be evenly divided over the concave cavity wall first sections, wherein each concave cavity wall first section may have the same length. Alternatively, the secondary first curvature length LCI,2 may be unevenly divided over the concave cavity wall first sections. Yet, especially, the concave cavity wall first sections may comprise a center concave cavity wall first section, and one or more sets of two concave cavity wall first sections, wherein the concave cavity wall first sections in each set may have the same length along the cavity wall first curvature length Lei (and wherein the concave cavity wall first sections in each set may be configured opposite each other along the cavity wall). In embodiments, the (combined) secondary first curvature length LCI,2 may be selected from the range of > 0.1*Lci, such as from the range of > 0.2*Lci, especially from the range of > 0.3*Lci. Additionally or alternatively, the (combined) secondary first curvature length LCI,2 may be selected from the range of < 0.7*Lci, such as from the range of < 0.6*Lci, especially from the range of < 0.5*Lci. Further, in embodiments, 0.1*Lci < LCI,2 < 0.7*Lci may apply, such as 0.2*Lci < LCI,2 < 0.6*Lci, especially 0.3*Lci < LCI,2 < 0.5*Lci. In embodiments, Lci,i + LCI,2 may be equal to Lei. That is, in embodiments, Lci,i + LCI,2 = Lei (may apply). Hence, in specific embodiments, the cavity wall may have a cavity wall first curvature length Lei in the at least one central axis parallel cross-sectional view of the central cavity; wherein the at least two convex cavity wall first sections may have a primary first curvature length Lci,i along the cavity wall first curvature length Lei; wherein 0.4*Lci < Lci,i < 0.8*Lci; wherein the at least one concave cavity wall first section may have a secondary first curvature length LCI,2 along the cavity wall first curvature length Lei; wherein 0.2*Lci < LCI,2 < 0.6*Lci. A lens wherein the convex cavity wall first sections may have an approximately equal or longer length along the cavity wall first curvature length Lei than the concave cavity wall first sections may facilitate that the perimeter of the central cavity (in the at least one central axis parallel cross- sectional view of the central cavity) may comprise an approximately equal or larger (combined) part configured to converge (or collimate) incident light than a (combined) part configured to diverge incident light, thereby providing a lens providing one or more focused “spots” of light (across a relative wide angular radiant intensity distribution). 2024PF80273

[0056] 19

[0057] The cavity wall may further comprise n cavity wall second sections in at least one central axis perpendicular cross-sectional view of the central cavity. The at least one central axis perpendicular cross-sectional view of the central cavity may especially be a cross-sectional view of the central cavity (taken) perpendicular to the lens arrangement center axis (AL). Further, in embodiments, the at least one central axis perpendicular cross-sectional view of the central cavity may especially be a central axis perpendicular cross-sectional view of the central cavity at the point at which the lens arrangement has an equivalent circular diameter equal to DL. In embodiments, n may be selected from the range of > 4, such as from the range of > 6, especially from the range of > 8. Further, in embodiments, n > 10 (may apply), such as n > 12, especially n > 14. Hence, in specific embodiments, n > 12 (may apply). A lens arrangement comprising > 12 cavity wall second sections may facilitate that the cavity wall may provide relatively more beam shaping, such that a radius of curvature of the lens arrangement second face may be decreased, as the lens arrangement second face may need to provide relatively less beam shaping. Hence, such a lens arrangement may provide a more compact and decorative lens arrangement.

[0058] The number of cavity wall second sections (in the at least one central axis perpendicular cross-sectional view of the central cavity) may thus be > 12. Especially, in embodiments, n > 14 (may apply), such as n > 16, especially n > 18. Additionally or alternatively, in embodiments, n < 36 (may apply), such as n < 32, especially n < 28. Further, in embodiments, 14 < n < 36 (may apply), such as 16 < n < 32, especially 18 < n < 28. Hence, in specific embodiments, 16 < n < 32. A lens arrangement comprising 16-32 cavity wall second sections in at least one central axis perpendicular cross-sectional view of the central cavity of said lens arrangement may facilitate that the lens arrangement may have suitable beam shaping properties, yet may be non-complex enough to allow for the use of relatively simple and cheap production methods.

[0059] In embodiments, the number n of cavity wall second sections may decrease along the cavity height He. In embodiments, the decrease in n may be gradual, i.e., (adjacent) cavity wall second sections may gradually merge together along the cavity height He. Alternatively, the number n of cavity wall second sections may decrease in steps, wherein the number of cavity wall second sections may abruptly decrease along the cavity height He. In embodiments, the cavity wall may comprise m cavity wall second sections in a first central axis perpendicular cross-sectional view. In embodiments, m = 16 may apply. Alternatively, and especially, m = 12 may apply. Further, the cavity wall may comprise n2 cavity wall second sections in a second central axis perpendicular cross-sectional view. The second 2024PF80273

[0060] 20 central axis perpendicular cross-sectional view may especially be (taken) closer to the lens arrangement apex than the first central axis perpendicular cross-sectional view. In embodiments, n2 = 4 may apply. Alternatively, and especially, n2 = 8 may apply. In embodiments, the transition from m to n2 cavity wall second sections (along the cavity height He) may occur gradually or step-wise, such as especially step-wise, or such as especially gradually. Hence, in specific embodiments, the cavity wall may comprise: (i) cavity wall second sections in a first central axis perpendicular cross-sectional view, wherein = 12 (may apply); and (ii) m cavity wall second sections in a second central axis perpendicular cross-sectional view, wherein n2 = 8 (may apply). Such a cavity wall may facilitate that the lens arrangement may be configured to shape (and / or steer) light incident on the cavity wall towards a bottom of the central cavity differently from light incident on the cavity wall towards a top of the central cavity (closest to the lens arrangement apex).

[0061] Hence, the number n of cavity wall second sections may decrease along the cavity height He. Especially, the number n may decrease along the cavity height He, wherein closest to the lens arrangement apex (at the top of the central cavity) n < 4, such as n < 2, especially n = 1 may apply. Hence, closest to the lens arrangement apex, the cavity wall may comprise one cavity wall second section in a central axis perpendicular cross-sectional view (of the central cavity). In embodiments, said one cavity wall second section may especially be concave (with respect to a geometrical center of the central cavity in the central axis perpendicular cross-sectional view). Hence, in specific embodiments, the number n of cavity wall second sections may decrease along the cavity height He; wherein closest to the lens arrangement apex the cavity wall may comprise one cavity wall second section in a central axis perpendicular cross-sectional view; wherein said one cavity wall second section may be concave. A lens arrangement comprising one cavity wall second section closest to the lens arrangement apex may facilitate that, closest to the lens arrangement apex, the cavity wall may have a circular or elliptical shape in a central axis perpendicular cross-sectional view, thereby facilitating that light incident on the cavity wall (from inside the center cavity) may be diverged, providing light with a wider angular radiant intensity distribution.

[0062] In embodiments, the cavity wall second sections may be alternatingly configured convex and concave (with respect to a geometrical center of the central cavity in the at least one central axis perpendicular cross-sectional view). That is, the cavity wall second sections may comprise at least one convex cavity wall second section and at least one concave cavity wall second section, wherein each convex cavity wall second section may be configured in physical contact with at least one concave cavity wall second section (and be 2024PF80273

[0063] 21 physically separated from all other convex cavity wall second sections), and each concave cavity wall second section may be configured in physical contact with at least one convex cavity wall second section (and be physically separated from all other concave cavity wall second sections). In embodiments, the inflection point between a convex cavity wall second section and a concave cavity wall second section may be defined as the point at which the curvature changes sign, as is known to the person skilled in the art.

[0064] In embodiments, the cavity wall may have a cavity wall second curvature length LC2 in the at least one central axis perpendicular cross-sectional view of the central cavity. Further, in embodiments, as indicated above, the cavity wall may comprise n cavity wall second sections (alternatingly configured convex and concave). In specific embodiments, n = 16 (may apply). In such embodiments, the n (or 16) cavity wall second sections may comprise (i) eight concave first cavity wall second sections, (ii) four convex second cavity wall second sections, and (iii) four convex third cavity wall second sections. Each of the (eight) concave first cavity wall second sections may have a primary second curvature length LC2,I along the cavity wall second curvature length Lc2. In embodiments, LC2,I may be selected from the range of > 0.025 *Lc2, such as from the range of > 0.035*Lc2, especially from the range of > 0.045*Lc2. Additionally or alternatively, LC2,I may be selected from the range of < 0.075*Lc2, such as from the range of < 0.065*Lc2, especially from the range of < 0.055*Lc2. Hence, in embodiments, 0.025*Lc2 < LC2,I < 0.075*Lc2 (may apply), such as 0.035*LC2 < LC2,I < 0.065*Lc2, especially 0.045*Lc2 < LC2,I < 0.055*Lc2. Further, (each of) the (eight) concave first cavity wall second sections may have a minimum primary second radius of curvature R2,I. In embodiments, the minimum primary second radius of curvature R2,I may be selected from the range of > 0.5 mm, such as from the range of > 1 mm, especially from the range of > 2 mm. Additionally or alternatively, R2,I may be selected from the range of < 30 mm, such as from the range of < 20 mm, especially from the range of < 15 mm. In embodiments, each of the (eight) concave first cavity wall second sections may have the same minimum primary second radius of curvature R2,I. Further, in embodiments, each of the (eight) concave first cavity wall second sections may have the same primary second curvature length LC2,I. Especially, the (eight) concave first cavity wall second sections may be (configured) identical.

[0065] As indicated above, the n (wherein n = 16) cavity wall second sections may comprise four convex second cavity wall second sections. Each of the (four) convex second cavity wall second sections may have a secondary second curvature length Lc2,2 along the cavity wall second curvature length Lc2. In embodiments, Lc2,2 may be selected from the 2024PF80273

[0066] 22 range of > 0.07*Lc2, such as from the range of > 0.09*Lc2, especially from the range of > 0.1 *LC2. Additionally or alternatively, Lc2,2 may be selected from the range of < 0.15*Lc2, such as from the range of < 0.13*Lc2, especially from the range of < 0.12*Lc2. Hence, in embodiments, 0.07*Lc2 < Lc2,2 < 0.15*Lc2 (may apply), such as 0.09*Lc2 < Lc2,2 < 0.13*Lc2, especially 0.1*Lc2 < Lc2,2 < 0.12*Lc2. Further, (each of) the (four) convex second cavity wall second sections may have a minimum secondary second radius of curvature R.2,2. In embodiments, the minimum secondary second radius of curvature R.2,2 may be selected from the range of > 3 mm, such as from the range of > 5 mm, especially from the range of > 7 mm. Additionally or alternatively, the minimum secondary second radius of curvature R2.2 may be selected from the range of < 60 mm, such as from the range of < 40 mm, especially from the range of < 30 mm. Further, in embodiments, the minimum secondary second radius of curvature R2.2 may be larger than the minimum primary radius of curvature R2.I, such as R2.2 > R2.I, like R2,2 > 4*R2,I, especially R2.2 > 5*R2,I. Such a difference between R2.2 and R2,I may facilitate that light incident on the cavity wall may be refracted into (and emitted as) a beam having four peaks in a radiant intensity distribution (in a plane perpendicular to a propagation direction of the beam). In embodiments, each of the (four) convex second cavity wall second sections may have the same minimum secondary second radius of curvature R2,2. Further, in embodiments, each of the (four) convex second cavity wall second sections may have the same secondary second curvature length Lc2,2. Especially, the (four) convex second cavity wall second sections may be (configured) identical.

[0067] Further, as indicated above, the n (wherein n = 16) cavity wall second sections may comprise four convex third cavity wall second sections. The (four) convex third cavity wall second sections may be configured alternating with the (four) convex second cavity wall second sections along the cavity wall (wherein the convex (second and third) second cavity wall second sections may be configured alternating with the concave first cavity wall second sections along the cavity wall). That is, the convex second cavity wall second sections and convex third cavity wall second sections may alternate along the cavity wall. Hence, along the cavity wall and in the at least one central axis perpendicular cross-sectional view of the central cavity, the cavity wall may comprise one or more repetitions (such as especially four repetitions) of the sequence: concave first cavity wall second section - convex second cavity wall second section - concave first cavity wall second section - convex third cavity wall second section.

[0068] Each of the (four) convex third cavity wall second sections may have a tertiary second curvature length Lc2,3 along the cavity wall second curvature length Lc2. In 2024PF80273

[0069] 23 embodiments, Lc2,3 may be selected from the range of > 0.015*Lc2, such as from the range of

[0070] > 0.025*LC2, especially from the range of > 0.035*Lc2. Additionally or alternatively, Lc2,3 may be selected from the range of < 0.065*Lc2, such as from the range of < 0.055*Lc2, especially from the range of < 0.045*Lc2. Hence, in embodiments, 0.015*Lc2 < Lc2,3 < 0.065*LC2 (may apply), such as 0.025*Lc2 < Lc2,3 < 0.055*Lc2, especially 0.035*Lc2 < Lc2,3 < 0.045*LC2. Further, in embodiments, (Lc2,2 / Lc2,3) > 1.4 (may apply), such as (Lc2,2 / Lc2,3)

[0071] > 1.6, especially (Lc2,2 / Lc2,3) > 1.8. Additionally or alternatively, in embodiments, (Lc2,2 / LC2,3) < 5.4 (may apply), such as (Lc2,2 / Lc2,3) < 5.2, especially (Lc2,2 / Lc2,3) < 5. Hence, in embodiments, 1.4 < (Lc2,2 / Lc2,3) < 5.4 (may apply), such as 1.6 < (Lc2,2 / Lc2,3) < 5.2, especially 1.8 < (Lc2,2 / Lc2,3) < 5. Further, in embodiments, LC2,I / Lc2,3) > 0.4 (may apply), such as (LC2,I / Lc2,3) > 0.6, especially (LC2,I / Lc2,3) > 0.8. Additionally or alternatively, in embodiments, (LC2,I / Lc2,3) < 2.8 (may apply), such as LC2,I / Lc2,3) < 2.6, especially (LC2,I / LC2,3) < 2.4. Hence, in embodiments, 0.4 < (LC2,I / Lc2,3) < 2.8 (may apply), such as 0.6 < (LC2,I / LC2,3) < 2.6, especially 0.8 < (LC2,I / Lc2,3) < 2.4.

[0072] Further, (each of) the (four) convex third cavity wall second sections may have a minimum tertiary second radius of curvature R2,3. In embodiments, the minimum tertiary second radius of curvature R.2,3 may be selected from the range of > 2 mm, such as from the range of > 4 mm, especially from the range of > 6 mm. Additionally or alternatively, the minimum tertiary second radius of curvature R.2,3 may be selected from the range of < 60 mm, such as from the range of < 40 mm, especially from the range of < 30 mm. Further, in embodiments, R.2,3 > R.2,1, such as R.2,3 > *R.2,I, especially R.2,3 > 3*R.2,I. In embodiments, each of the (four) convex third cavity wall second sections may have the same minimum tertiary second radius of curvature R.2,3. Further, in embodiments, each of the (four) convex third cavity wall second sections may have the same tertiary second curvature length Lc2,3. Especially, the (four) convex third cavity wall second sections may be (configured) identical. Hence, in specific embodiments, the cavity wall may comprise n cavity wall second sections, wherein n = 16; wherein the cavity wall may have a cavity wall second curvature length Lc2 in the at least one central axis perpendicular cross-sectional view of the central cavity; wherein the n cavity wall second sections may comprise (i) eight concave first cavity wall second sections; (ii) four convex second cavity wall second sections; and (iii) four convex third cavity wall second sections; wherein: (A) each of the concave first cavity wall second sections may have a primary second curvature length LC2,I along the cavity wall second curvature length Lc2; (B) the convex second cavity wall second sections and convex third cavity wall second sections may alternate along the cavity wall; wherein each of the convex 2024PF80273

[0073] 24 second cavity wall second sections may have a secondary second curvature length Lc2,2 along the cavity wall second curvature length Lc2; wherein each of the convex third cavity wall second sections may have a tertiary second curvature length Lc2,3 along the cavity wall second curvature length Lc2; wherein 1.6 < (Lc2,2 / Lc2,3) < 5.2; and (C) 0.6 < (LC2,I / Lc2,3) < 2.6. A lens arrangement comprising such a cavity wall (in at least one central axis perpendicular cross-sectional view of the central cavity) may especially provide a beam of light having four peaks (upon placing a source of light in or in front of the central cavity).

[0074] In embodiments, the central cavity (comprising the 16 cavity wall second sections as described above) may be mirror-symmetric in the central axis perpendicular cross-sectional view. Especially, the central cavity may be symmetric about a first mirror plane (Pmi) (configured) parallel to and intersecting the lens arrangement center axis (AL). Further, the central cavity may be symmetric about a second mirror plane (Pm2) configured perpendicular to the first mirror plane (Pmi)(, parallel to the lens arrangement center axis (AL),) and intersecting the lens arrangement center axis (AL). Especially, the central cavity may have rotational symmetry of order 4 (about the lens arrangement center axis (AL)). Hence, in specific embodiments, the central cavity may be mirror-symmetric in the central axis perpendicular cross-sectional view; wherein the central cavity may be symmetric about a first mirror plane (Pmi) parallel to and intersecting the lens arrangement center axis (AL); wherein the central cavity may further be symmetric about a second mirror plane (Pm2) configured perpendicular to the first mirror plane (Pmi) and intersecting the lens arrangement center axis (AL). A central cavity having rotational symmetry of order 4 may facilitate providing a beam of light having rotational symmetry of order 4. Especially, a lens arrangement comprising a central cavity having rotational symmetry of order 4 may be configured to provide a beam of light having four peaks of (approximately) equal intensity (upon placing a source of light in or in front of the central cavity).

[0075] In alternative embodiments, the cavity wall may comprise n cavity wall second sections (in the at least one central axis perpendicular cross-sectional view), wherein n = 12. In such embodiments, the central cavity may especially have an elongated shape in the central axis perpendicular cross-sectional view. The elongated shape may have a first axis of elongation (Ai) (wherein the first axis of elongation (Ai) may be configured perpendicular to the lens arrangement center axis (AL), and wherein the central cavity may be elongated along the first axis of elongation (Ai)). In embodiments, the elongated shape of the central cavity (in the central axis perpendicular cross-sectional view) may approximate an ellipse. The term “approximate” and its conjugations herein, such as in “to approximate a shape”, 2024PF80273

[0076] 25 refers to being nearly identical to, especially identical to, the following term, for example nearly identical to an elliptical shape. For example, the central cavity may define an elliptical shape but for a defect. In particular, an object approximating a first shape may herein refer to: a first shape realization encompassing the object, wherein the first shape realization is defined as the smallest encompassing shape of the (2D or 3D, respectively) object wherein the first shape realization has the shape of the first shape, wherein a ratio of the area (volume) of the first shape realization to the area (volume) of the object is < 1.2, especially < 1.1, such as <1.05, especially <1.02. For instance, the central cavity may approximate an elliptical shape, wherein the first shape realization may be defined as the smallest encompassing elliptical shape of the central cavity, wherein a ratio of the volume of the first shape realization to the volume of the central cavity is < 1.2, especially, especially < 1.1, such as <1.05, especially <1.02, including 1. Further, if the dimensions of the first shape are defined, the term approximate may refer to the object and the first shape being superimposable (in 2D or 3D, respectively) such that an intersection between the object and the first shape covers at least n% of the object and at least n% of the shape, wherein n is at least 90%, such as at least 95%, especially at least 98%, such as at least 99%, including 100%.

[0077] In embodiments, the n (or 12) cavity wall second sections (of the central cavity having the elongated shape) may comprise (i) two concave first cavity wall second sections, (ii) four concave second cavity wall second sections, (iii) two convex third cavity wall second sections, and (iv) four convex fourth cavity wall second sections. The (two) concave first cavity wall second sections may be configured on opposite ends of the cavity wall (in the central axis perpendicular cross-sectional view). Further, the first axis of elongation (Ai) may be configured intersecting (the geometrical centers of) the (two) concave first cavity wall second sections. In embodiments, each of the (two) concave first cavity wall second sections may have a primary second curvature length LC2,I along the cavity wall second curvature length Lc2. In embodiments, LC2,I may be selected from the range of > 0.18*LC2, such as from the range of > 0.2*LC2, especially from the range of > 0.22*LC2. Additionally or alternatively, LC2,I may be selected from the range of < 0.32*LC2, such as from the range of < 0.3*LC2, especially from the range of < 0.28*LC2. Hence, in embodiments, 0.18*LC2 < LC2,I < 0.32*LC2 (may apply), such as 0.2*LC2 < LC2,I < 0.3*LC2, especially 0.22*LC2 < LC2,I < 0.28*LC2. Further, (each of) the (two) concave first cavity wall second sections may have a minimum primary second radius of curvature R2,I. The minimum primary second radius of curvature R.2,1 may be selected from the range of > 1.5 mm, such as from the range of > 3 mm, especially from the range of > 4.5 mm. Additionally or 2024PF80273

[0078] 26 alternatively, the minimum primary second radius of curvature R.2,1 may be selected from the range of < 45 mm, such as from the range of < 30 mm, especially from the range of < 25 mm. In embodiments, both of the concave first cavity wall second sections may have the same minimum primary second radius of curvature R2,I. Further, both of the concave first cavity wall second sections may have the same primary second curvature length LC2,L Especially, the (two) concave first cavity wall second sections may be (configured) identical.

[0079] As indicated above, the n (wherein n = 12) cavity wall second sections may comprise four concave second cavity wall second sections. Two of the four concave second cavity wall second sections may be configured on a first side of the first axis of elongation (Ai) (between the concave first cavity wall second sections), and two of the four concave second cavity wall second sections may be configured on a second (opposite) side of the first axis of elongation (Ai) (between the concave first cavity wall second sections). Further, each of the (four) concave second cavity wall second sections may have a secondary second curvature length Lc2,2 along the cavity wall second curvature length Lc2. In embodiments, LC2,2 may be selected from the range of > 0.022*Lc2, such as from the range of > 0.025 *Lc2, especially from the range of > 0.027*Lc2. Additionally or alternatively, Lc2,2 may be selected from the range of < 0.064*Lc2, such as from the range of < 0.06*Lc2, especially from the range of < 0.056*Lc2. Hence, in embodiments, 0.022*Lc2 < Lc2,2 < 0.064*Lc2 (may apply), such as 0.025*LC2 < Lc2,2 < 0.06*Lc2, especially 0.027*Lc2 < Lc2,2 < 0.056*Lc2. Further, in embodiments, LC2,I > 4*Lc2,2 (may apply), such as LC2,I > 5*Lc2.2, especially LC2,I > 6*Lc2,2. Additionally or alternatively, in embodiments, LC2,I < 9*Lc2,2 (may apply), such as LC2,I < 8*LC2.2, especially LC2,I < 7*Lc2,2. Hence, in embodiments, 4*Lc2,2 < LC2,I < 9*Lc2,2 (may apply), such as 5*Lc2,2 < LC2,I < 8*Lc2.2, especially 6*Lc2,2 < LC2,I < 7*Lc2,2. Further, (each of) the (four) concave second cavity wall second sections may have a minimum secondary second radius of curvature R.2,2. In embodiments, the minimum secondary second radius of curvature R.2,2 may be selected from the range of > 2 mm, such as from the range of > 4 mm, especially from the range of > 6 mm. Additionally or alternatively, the minimum secondary second radius of curvature R2.2 may be selected from the range of < 60 mm, such as from the range of < 40 mm, especially from the range of < 30 mm. In embodiments, each of the (four) concave second cavity wall second sections may have the same minimum secondary second radius of curvature R2,2. Further, in embodiments, each of the (four) concave second cavity wall second sections may have the same secondary second curvature length Lc2,2. Especially, the (four) concave second cavity wall second sections may be (configured) identical. 2024PF80273

[0080] 27

[0081] Further, as indicated above, the n (wherein n = 12) cavity wall second sections may comprise two convex third cavity wall second sections. The (two) convex third cavity wall second sections may be configured on opposite sides of the cavity wall (and on opposite sides of the first axis of elongation Ai). Further, each of the two convex third cavity wall second sections may be configured between two (of the) concave second cavity wall second sections. Each of the (four) convex third cavity wall second sections may have a tertiary second curvature length Lc2,3 along the cavity wall second curvature length Lc2. In embodiments, Lc2,3 may be selected from the range of > 0.022*Lc2, such as from the range of > 0.025*LC2, especially from the range of > 0.027*Lc2. Additionally or alternatively, Lc2,3 may be selected from the range of < 0.064*Lc2, such as from the range of < 0.06*Lc2, especially from the range of < 0.056*Lc2. Hence, in embodiments, 0.022*Lc2 < Lc2,3 < 0.064*LC2 (may apply), such as 0.025*Lc2 < Lc2,3 < 0.06*Lc2, especially 0.027*Lc2 < Lc2,3 < 0.056*LC2. Further, in embodiments, LC2,I > 4*Lc2,3 (may apply), such as LC2,I > 5*Lc2,3, especially LC2,I > 6*Lc2,3. Additionally or alternatively, in embodiments, LC2,I < 9*Lc2,3 (may apply), such as LC2,I < 8*Lc2,3, especially LC2,I < 7*Lc2,3. Hence, in embodiments, 4*Lc2,3 < LC2,I < 9*LC2,3 (may apply), such as 5*Lc2,3 < LC2,I < 8*Lc2,3, especially 6*Lc2,3 < LC2,I < 7*LC2,3. Further, (each of) the (two) convex third cavity wall second sections may have a minimum tertiary second radius of curvature R2,3. In embodiments, the minimum tertiary second radius of curvature R.2,3 may be selected from the range of > 4 mm, such as from the range of > 6 mm, especially from the range of > 9 mm. Additionally or alternatively, the minimum tertiary second radius of curvature R.2,3 may be selected from the range of < 120 mm, such as from the range of < 80 mm, especially from the range of < 60 mm. In embodiments, both of the convex third cavity wall second sections may have the same minimum tertiary second radius of curvature R.2,3. Further, both of the convex third cavity wall second sections may have the same tertiary second curvature length Lc2,3. Especially, the (two) convex third cavity wall second sections may be (configured) identical.

[0082] As indicated above, the n (wherein n = 12) cavity wall second sections may comprise four convex fourth cavity wall second sections. Two of the four convex fourth cavity wall second sections may be configured on a first side of the first axis of elongation (Ai) (between the concave first cavity wall second sections), and two of the four convex fourth cavity wall second sections may be configured on a second (opposite) side of the first axis of elongation (Ai) (between the concave first cavity wall second sections). Further, each of the four convex fourth cavity wall second sections may be configured between a concave first cavity wall second section and a concave second cavity wall second section. Each of the 2024PF80273

[0083] 28

[0084] (four) convex fourth cavity wall second sections may have a quaternary second curvature length LC2,4 along the cavity wall second curvature length Lc2. In embodiments, Lc2,4 may be selected from the range of > 0.022*Lc2, such as from the range of > 0.025*Lc2, especially from the range of > 0.027*Lc2. Additionally or alternatively, Lc2,4 may be selected from the range of < 0.064*Lc2, such as from the range of < 0.06*Lc2, especially from the range of < 0.056*LC2. Hence, in embodiments, 0.022*Lc2 < Lc2,4 < 0.064*Lc2 (may apply), such as 0.025*LC2 < LC2,4 < 0.06*LC2, especially 0.027*Lc2 < Lc2,4 < 0.056*Lc2. Further, in embodiments, LC2,I > 4*Lc2,4 (may apply), such as LC2,I > 5*Lc2,4, especially LC2,I > 6*Lc2,4. Additionally or alternatively, in embodiments, LC2,I < 9*Lc2,4 (may apply), such as LC2,I < 8*LC2.4, especially LC2,I < 7*Lc2,4. Hence, in embodiments, 4*Lc2,4 < LC2,I < 9*Lc2,4 (may apply), such as 5*Lc2,4 < LC2,I < 8*Lc2.4, especially 6*Lc2,4 < LC2,I < 7*Lc2,4. As indicated above, the (two) concave first cavity wall second sections may have a (much) longer curvature length (along the cavity wall second curvature length Lc2) than the concave second cavity wall second sections, the convex third cavity wall second sections, and the convex fourth cavity wall second sections. This may facilitate that the elongated cavity may be configured such that light incident on the cavity wall may be guided in the direction of the longer concave first cavity wall second sections, thereby providing a beam of light having two peaks in a radiant intensity distribution.

[0085] (Each of) the (four) convex fourth cavity wall second sections may have a minimum quaternary second radius of curvature R2,4. In embodiments, the minimum quaternary second radius of curvature R.2,4 may be selected from the range of > 0.5 mm, such as from the range of > 1 mm, especially from the range of > 2 mm. Additionally or alternatively, the minimum quaternary second radius of curvature R.2,4 may be selected from the range of < 90 mm, such as from the range of < 60 mm, especially from the range of < 45 mm. Further, in embodiments, R.2,3 > R.2,4 may apply, such as R.2,3 > 1.1*R.2,4, especially R.2,3 > 1.2*R2,4. Additionally or alternatively, R2,3 < 10*R2,4 may apply, such as R2,3 < 8*R2,4, especially R2,3 < 6*R2,4. In embodiments, each of the (four) convex fourth cavity wall second sections may have the same minimum quaternary second radius of curvature R2,4. Further, in embodiments, each of the (four) convex fourth cavity wall second sections may have the same quaternary second curvature length Lc2,4. Especially, the (four) convex fourth cavity wall second sections may be (configured) identical. Hence, in specific embodiments, the cavity wall may comprise n cavity wall second sections, wherein n = 12; wherein the cavity wall may have a cavity wall second curvature length Lc2 in the at least one central axis perpendicular cross-sectional view of the central cavity; wherein the central cavity may have 2024PF80273

[0086] 29 an elongated shape in the central axis perpendicular cross-sectional view; wherein the elongated shape may have a first axis of elongation (Ai); wherein the n cavity wall second sections may comprise (i) two concave first cavity wall second sections; (ii) four concave second cavity wall second sections; (iii) two convex third cavity wall second sections; and (iv) four convex fourth cavity wall second sections; wherein: (A) each of the concave first cavity wall second sections may have a primary second curvature length LC2,I along the cavity wall second curvature length Lc2; wherein each of the concave second cavity wall second sections may have a secondary second curvature length Lc2,2 along the cavity wall second curvature length Lc2; wherein 5*Lc2,2 < LC2,I < 8*Lc2,2 and 0.2*Lc2 < LC2,I < 0.3*Lc2; (B) the concave first cavity wall second sections may be configured on opposite ends of the cavity wall; wherein the first axis of elongation (Ai) may be configured intersecting the concave first cavity wall second sections; and (C) each of the convex third cavity wall second sections may be configured between two concave second cavity wall second sections; wherein the convex third cavity wall second sections may have a minimum tertiary second radius of curvature R2.3; wherein the convex fourth cavity wall second sections may have a minimum quaternary second radius of curvature R.2,4; wherein R.2,3 > R.2,4. A lens arrangement comprising such a cavity wall (in at least one central axis perpendicular cross-sectional view of the central cavity) may especially provide a beam of light having two peaks (upon placing a source of light in or in front of the central cavity).

[0087] The central cavity (having an elongated shape and comprising the 12 cavity wall second sections as described above) may be mirror-symmetric in the central axis perpendicular cross-sectional view. Especially, the first axis of elongation (Ai) may define a first mirror plane (Pmi) of the central cavity (in the central axis perpendicular cross-sectional view). Further, the central cavity (having an elongated shape and comprising the 12 cavity wall second sections as described above) may have a second mirror plane (Pm2) in the central axis perpendicular cross-sectional view. The second mirror plane (Pm2) may especially be configured perpendicular to the first mirror plane (Pmi) and intersecting a geometrical center of the central cavity. Further, the second mirror plane (Pm2) may be configured intersecting the lens arrangement center axis (AL) and (both of) the convex third cavity wall second sections. In embodiments, the central cavity may further be configured symmetric about the second mirror plane (Pm2) in the central axis perpendicular cross-sectional view. Hence, in specific embodiments, the central cavity may be mirror-symmetric in the central axis perpendicular cross-sectional view; wherein the first axis of elongation (Ai) may define a first mirror plane (Pmi) of the central cavity; wherein the central cavity may have a second 2024PF80273

[0088] 30 mirror plane (Pm2) in the central axis perpendicular cross-sectional view; wherein the second mirror plane (Pm2) may be configured perpendicular to the first mirror plane (Pmi) and intersecting a geometrical center of the central cavity; wherein the central cavity may be further configured symmetric about the second mirror plane (Pm2) in the central axis perpendicular cross-sectional view. Such a central cavity, being mirror symmetric in two orthogonal directions, may may facilitate providing a beam of light being mirror symmetric in two orthogonal directions. Especially, a lens arrangement comprising a central cavity being mirror symmetric in two orthogonal directions may be configured to provide a beam of light having two peaks of (approximately) equal intensity (upon placing a source of light in or in front of the central cavity).

[0089] In embodiments, the optical element arrangement may comprise a plurality of microlenses. The plurality of microlenses may be configured on or comprised by (at least part of) one or more of the cavity wall and the lens arrangement second face. Especially, a production method of the optical element arrangement may comprise producing the (u*v) lens arrangements, and placing a plurality of microlenses on (at least part of) one or more of the cavity wall and the lens arrangement second face, such that the plurality of microlenses may be configured on said (at least part of) one or more of the cavity wall and the lens arrangement second face. Alternatively, a production method of the optical element arrangement may comprise producing the (u*v) lens arrangements comprising the plurality of microlenses (as a single component), such that the plurality of microlenses may be comprised by (at least part of) one or more of the cavity wall and the lens arrangement second face. Especially, the plurality of microlenses may be configured on or comprised by (at least part of) the lens arrangement second face. In embodiments, the plurality of microlenses may be configured on or comprised by the lens arrangement second face (and / or the cavity wall) of at least one lens arrangement in the optical element arrangement (i.e., at least one lens arrangement may comprise or be physically coupled with the microlenses). Further, in embodiments, the plurality of microlenses may be configured on or comprised by the lens arrangement second face (and / or the cavity wall) of all of the lens arrangements in the optical element arrangement (i.e., all lens arrangements may comprise or be physically coupled with the microlenses).

[0090] The microlenses may be configured convex or concave with respect to a geometrical center of the lens arrangement. Especially, the plurality of microlenses may be configured concave with respect to the geometrical center of the lens arrangement (that is, the plurality of microlenses may appear to extend from the lens arrangement second face (and / or 2024PF80273

[0091] 31 the cavity wall)). Further, in embodiments, the microlenses may be spherical microlenses or aspherical microlenses. Hence, in embodiments, the microlenses may be spherical microlenses, wherein the microlenses may (each) have a single microlens radius of curvature Rmi. In embodiments, the microlens radius of curvature Rmimay be selected from the range of > 0.5 mm, such as from the range of > 1 mm, especially from the range of > 1.5 mm. Additionally or alternatively, the microlens radius of curvature Rmimay be selected from the range of < 15 mm, such as from the range of < 10 mm, especially from the range of < 7.5 mm. In embodiments, all of the microlenses configured on or comprised by a single lens arrangement may be spherical lenses. Further, all of the microlenses in the optical element arrangement may be spherical lenses. Alternatively, at least some of the microlenses may be aspherical microlenses having a plurality of radii of curvature. In such embodiments, the aspherical microlenses may have a smallest microlens radius of curvature Especially, the aspherical microlenses may have the smallest microlens radius of curvature Rmi, min in a (geometrical) center of the microlens, wherein the radius of curvature may increase (radially) with increasing distance from the center of the microlens. In embodiments, the smallest microlens radius of curvature Rmi, min may be selected from the range of > 0.5 mm, such as from the range of > 1 mm, especially from the range of > 1.5 mm. Additionally or alternatively, the smallest microlens radius of curvature Rmi,min may be selected from the range of < 15 mm, such as from the range of < 10 mm, especially from the range of < 7.5 mm. In embodiments, all of the microlenses configured on or comprised by a single lens arrangement may be aspherical lenses. Further, all of the microlenses in the optical element arrangement may be aspherical lenses. Alternatively, the optical element arrangement may comprise both spherical and aspherical microlenses. In such embodiments, some of the lens arrangements may comprise or be physically coupled with (only) spherical microlenses, and some of the lens arrangements may comprise or be physically coupled with (only) aspherical microlenses. Further, a (single) lens arrangement may comprise or be physically coupled with a combination of spherical and aspherical microlenses.

[0092] In embodiments, the plurality of microlenses may be arranged in a microlens array (on the one or more of the lens arrangement second face and the cavity wall, such as especially on the lens arrangement second face). The microlens array may be a regular array or a tessellation array. Especially, the microlens array may be a regular array, wherein the microlenses may be arranged in a rectangular (such as square) grid in the microlens array. Alternatively, the microlens array may be a tessellation array, wherein the microlenses may be arranged in a hexagonal grid (i.e., the microlenses may form a “honeycomb structure”) in 2024PF80273

[0093] 32 the microlens array. Further, the microlens array may be a tessellation array, such as a phyllotaxis (or “sunflower”) tessellation. In embodiments, the microlenses may be configured in physical contact with each other in the microlens array. In such embodiments, (a projection of) the boundaries between (adjacent) microlenses (on a curved plane parallel to the lens arrangement second face and / or the cavity wall) may determine a shape of the microlenses. In embodiments, the microlenses may thus have a microlens shape. The microlens shape may be selected from the group of a rectangle, a regular (simple) n-gonal shape (wherein 3 < n < 24), and an irregular shape. Especially, the microlens array may be a regular array, wherein the microlenses may have a rectangular shape. Alternatively, the microlens array may be a tessellation array, wherein the microlenses may have a regular (simple) n-gonal shape (such as especially a hexagonal shape) or an irregular shape (e.g. in case of a phyllotaxis tessellation). In embodiments, the microlenses may be configured in physical contact with each other via one or more fillets. The term “fillet” is known to the person skilled in the art, and may herein refer to a (rounded) transition between two microlenses. The fillet may especially be a concave rounded transition between microlenses (with respect to an outside of the lens arrangement). That is, would the lenses for instance be configured on the lens arrangement second face, a center of the one or more fillets may be configured curving towards the lens arrangement second face (and the edges of the one or more fillets may be configured curving away from the lens arrangement second face). Hence, the one or more fillets may physically couple the plurality of microlenses, wherein the one or more fillets may be configured between adjacent lenses.

[0094] The microlenses (in the microlens array) may have an equivalent circular microlens diameter Dmi, wherein the equivalent circular microlens diameter Dmimay especially be determined from the microlens shape. In embodiments, the equivalent circular microlens diameter Dmimay be selected from the range of > 0.5 mm, such as from the range of > 0.75 mm, especially from the range of > 1 mm. Additionally or alternatively, the equivalent circular microlens diameter Dmimay be selected from the range of < 25 mm, such as from the range of < 20 mm, especially from the range of < 15 mm. Further, in embodiments, Di / Dmi > 5 (may apply), such as Di / Dmi > 10, especially Di / Dmi > 15. Additionally or alternatively, in embodiments, Di / Dmi < 100 (may apply), such as Di / Dmi < 80, especially Di / Dmi < 50. Hence, in specific embodiments, the optical element arrangement may comprise a plurality of microlenses; wherein the plurality of microlenses may be configured on or comprised by one or more of the cavity wall and the lens arrangement second face; wherein the microlenses may have an equivalent circular microlens diameter 2024PF80273

[0095] 33

[0096] Dmi, wherein Di / Dmi > 10; wherein the plurality of microlenses may be arranged in a microlens array; and wherein the microlenses may be configured in physical contact with each other in the microlens array. An optical element arrangement comprising a plurality of microlenses may facilitate further shaping and / or steering of a beam of light transmitted through the optical element arrangement. Further, depending on the type of microlens array used, such an optical element arrangement may be more decorative.

[0097] As indicated above, the microlenses may be comprised by the lens arrangement second face and / or the cavity wall. Especially, the microlenses may be comprised by the lens arrangement second face. In such embodiments, a radius of curvature of the microlenses (Rmiand / or Rmi,min) may be determined separately from a radius of curvature of the lens arrangement second face (Ri, Rmin, and / or RL). Especially, a virtual lens arrangement second face may be determined, wherein the virtual lens arrangement second face may be identical to the lens arrangement second face of a lens arrangement not comprising a plurality of microlenses, and wherein a radius of curvature (Ri, Rmin, and / or RL) of the lens arrangement second face comprising the microlenses may be determined from the virtual lens arrangement second face. The virtual lens arrangement second face may be a smooth surface that deviates from the lens arrangement second face comprising microlenses by a distance of at most 0.5*Dmi. Herein, the term “smooth” may especially indicate that a radius of curvature of the virtual lens arrangement second face may either stay the same or increase upon moving outward from a geometrical center of the virtual lens arrangement second face, wherein a smallest radius of curvature of the virtual lens arrangement second face may be > Rmin.

[0098] According to a further aspect, the invention provides a light generating system comprising the optical element arrangement as described herein. Further, the light generating system may comprise a source of light. In embodiments, at least one of the cavities (of at least one of the lens arrangements) may be configured in a light receiving relationship with the source of light. The source of light may be configured to generate a first beam of light. Further, the optical element arrangement may be configured to convert the first beam of light into a second beam of light. The second beam of light may especially have a radiant intensity distribution in a first plane (Pi) perpendicular to the lens arrangement center axis (AL). In embodiments, the radiant intensity distribution (of the second beam of light) may comprise at least two peaks. Hence, in specific embodiments, the invention provides a light generating system comprising the optical element arrangement as described above and a source of light, wherein at least one of the central cavities is configured in a light receiving relationship with 2024PF80273

[0099] 34 the source of light; the source of light is configured to generate a first beam of light; wherein the optical element arrangement is configured to convert the first beam of light into a second beam of light; wherein the second beam of light has a radiant intensity distribution in a first plane (Pi) perpendicular to the lens arrangement center axis (AL); wherein the radiant intensity distribution comprises at least two peaks. Such a light generating system may facilitate that a radiant intensity distribution comprising at least two peaks may be produced from a single source of light. Further, such a light generating system may be more decorative, as the source of light may not be directly visible behind the optical element arrangement, and the optical element arrangement may have a decorative appearance.

[0100] The light generating system may thus comprise a source of light. The source of light may in embodiments be at least partly configured in the central cavity of one of the lens arrangements. That is, the at least one of the central cavities (configured in a light receiving relationship with the source of light) may (be configured to) at least partly host the source of light. Especially, looking along the lens arrangement center axis (AL) from a direction of the lens arrangement apex, the central cavity may (essentially fully) cover the source of light. Further, viewing the light generating system from a direction perpendicular to the lens arrangement center axis (AL), the source of light may be at least partially configured (extending) in(to) the central cavity of a lens arrangement. Especially, the source of light may have a light emitting surface, wherein the first beam of light may be emitted from the light emitting surface, and wherein the light emitting surface may be configured in the central cavity. Hence, in specific embodiments, the at least one of the central cavities may at least partly host the source of light. At least partly configuring the source of light in the central cavity may provide the benefit that (essentially) all of the (first beam of) light emitted by the source of light may be incident on the cavity wall, thereby improving the efficiency of the light generating system (and / or preventing “leakage of light” around the edges of the lens arrangement).

[0101] Alternatively, the source of light may be configured outside of the central cavity. Especially, viewing the light generating system from a direction perpendicular to the lens arrangement center axis (AL), the source of light (such as especially the light emitting surface) may be configured on an outside of the central cavity, and physically separated from the lens arrangement. Hence, the source of light may be configured at a shortest distance dsifrom the lens arrangement. In embodiments, the shortest distance dsi between the source of light and the lens arrangement may be selected from the range of > 0.5 mm, such as from the range of > 1 mm, especially from the range of > 2 mm. Additionally or alternatively, the 2024PF80273

[0102] 35 shortest distance dsibetween the source of light and the lens arrangement may be selected from the range of < 30 mm, such as from the range of < 20 mm, especially from the range of < 10 mm. Here below, some general embodiments relating to the source of light are provided.

[0103] The term “source of light” (or “light source”) may in principle relate to any light source known in the art. In a specific embodiment, the light source may comprise a solid state light source (such as an LED or laser diode). The term “light source” may also refer to a chip scale package (CSP) and / or a chip scale packaged (CSP) LED. A CSP may comprise a single solid state die (such as a LED) with provided thereon a luminescent material comprising layer. The term “light source” may also refer to a midpower package. A midpower package may comprise one or more solid state die(s), optionally covered by a luminescent material comprising layer. The die dimensions may be < 2 mm, such as in the range of e.g. 0.2-2 mm. Herein, the term “light source” may also refer to mini LEDs or micro LEDs, such as especially micro LEDs or “microLEDs”. Herein, the term mini LED refers to solid state light sources having (die) dimensions, especially length and width, selected from the range of 0.1-1 mm. Further, the term micro LED refers to solid state light sources having (die) dimensions, especially length and width, selected from the range of < 100 pm.

[0104] The term “light source” may refer to a semiconductor light-emitting device, such as an LED, a resonant cavity LED (RCLED), a vertical cavity laser diode (VCSELs), an edge emitting laser, etc... The term “light source” may also refer to an organic LED (OLED), such as a passive-matrix (PMOLED) or an active-matrix (AMOLED). In an embodiment, the solid state light source may be selected from the group of a LED, a laser diode, a superluminescent diode, or a multi -junction LED.

[0105] The light source may be configured to provide primary radiation, which is used as such, such as e.g. a blue light source, like a blue LED. Such LEDs may be indicated as direct color LEDs. In other embodiments, the light source may be configured to provide primary radiation and part of the primary radiation may converted into secondary radiation (e.g. by a luminescent material). Secondary radiation may be based on conversion by a luminescent material. The luminescent material may be comprised by the light source, such as an LED with a luminescent material layer or dome. Such LEDs may be indicated as phosphor converted LEDs or PC LEDs.

[0106] In embodiments, the source of light may be a laser light source. The term “laser light source” especially refers to a laser. Such laser may be configured to generate laser light source light having one or more wavelengths in the UV, visible, or infrared. The term “laser” especially refers to a device that emits light through a process of optical amplification 2024PF80273

[0107] 36 based on the stimulated emission of electromagnetic radiation. In embodiments, the term “laser” may refer to a solid-state laser. In specific embodiments, the terms “laser” or “laser light source”, or similar terms, may refer to a laser diode. Hence, in embodiments the light source may comprise laser diodes. In embodiments, the term “laser” may refer to one or more of cerium doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF), chromium doped chrysoberyl (alexandrite) laser, chromium ZnSe (CrZnSe) laser, divalent samarium doped calcium fluoride (Sm:CaF2) laser, Er: YAG laser, erbium doped and erbiumytterbium codoped glass lasers, F-Center laser, holmium YAG (Ho:YAG) laser, Nd:YAG laser, NdCrYAG laser, neodymium doped yttrium calcium oxoborate Nd: YCa4O(BO3)3 or Nd:YCOB, neodymium doped yttrium orthovanadate (Nd YVCU) laser, neodymium glass (Nd:glass) laser, neodymium YLF (Nd:YLF) solid-state laser, promethium 147 doped phosphate glass (147Pm3+:glass) solid-state laser, ruby laser (AhO3:Cr3+), thulium YAG (Tm:YAG) laser, titanium sapphire (Ti:sapphire; AhO3:Ti3+) laser, trivalent uranium doped calcium fluoride (U:CaF2) solid-state laser, Ytterbium doped glass laser (rod, plate / chip, and fiber), Ytterbium YAG (Yb:YAG) laser, Yb2O3 (glass or ceramics) laser, etc. Further, the term “laser” may refer to one or more of a semiconductor laser diodes, such as GaN, InGaN, AlGalnP, AlGaAs, InGaAsP, lead salt, vertical cavity surface emitting laser (VCSEL), quantum cascade laser, hybrid silicon laser, etc. Suitable solid state lasers may be selected from (III-V compound) semiconductor lasers, such as in specific embodiments semiconductor lasers selected from the group of GaN, AlGaN, InGaN, and AlGalnN, (especially for blue-green), GaP, InP, GalnP, and AlGalnP (especially for red-NIR), GaAs, AlGaAs, InGaAs, and InGaAsP (especially for NIR-MIR). Hence, in embodiments one or more of the light generating devices may comprise a semiconductor laser selected from the group of GaN, AlGaN, InGaN, AlGalnN, GaP, InP, GalnP, and AlGalnP lasers. The term “laser”, and similar terms, may thus refer to a solid state laser based on a crystalline or glass body doped with ions, like transition metal ions and / or lanthanide ions, to a fiber laser, to a photonic crystal laser, to a semiconductor laser (laser diode or diode laser), etc.

[0108] In embodiments, laser light sources may be arranged in a laser bank. The laser bank may in embodiments comprise heat sinking and / or optics (e.g. a lens to collimate the laser light). Hence, in embodiments lasers in a laser bank (or “laser array bank”) may share the same optics. The light source light may be a focused or collimated beam of (laser) light source light. The term “focused” may especially refer to converging to a small spot. Focusing (of the laser light source light) may be executed with one or more optics, such as especially two (focusing) lenses. Collimation may be executed with one or more (other) optics, like 2024PF80273

[0109] 37 collimation elements, such as lenses and / or parabolic mirrors. In embodiments, the sub-beam of (laser) light source light may be relatively highly collimated, such as < 2° FWHM, like < 1° FWHM, especially < 0.5° FWHM.

[0110] In embodiments, the source of light may comprise a plurality of solid state light sources. Especially, in embodiments, the source of light may comprise a plurality of solid state light sources, wherein the solid state light sources may be selected from the group of LEDs, laser diodes, superluminescent diodes, and (stacked) multi -junction LEDs. Further, the plurality of solid state light sources may be configured in a second array. The second array may especially be a (regular) x*y array. In embodiments, x > 1 (may apply), such as x > 2, especially x > 3. Additionally or alternatively, in embodiments, x < 8 (may apply), such as x < 7, especially x < 6. Further, in embodiments, y > 1 (may apply), such as y > 2, especially y > 3. Additionally or alternatively, in embodiments, y < 8 (may apply), such as y < 7, especially y < 6. In embodiments, x and y may be selected such, that the total number of solid state light sources in the second array (defined by x*y) may be at least 2, such as at least 4, especially at least 6. Additionally or alternatively, x and y may be selected such, that the total number of solid state light sources in the second array (defined by x*y) may be at most 12, such as at most 10, especially at most 8. In embodiments, the second array may comprise at least two rows or at least two solid state light sources per row. That is, one may apply of: (i) x > 2 and y > 1, and (ii) x > 1 and y > 2. Especially, the second array may comprise at least two rows and at least two solid state light sources per row. That is, x > 2 and y > may apply. Hence, in specific embodiments, the source of light may comprise a plurality of solid state light sources configured in a second array; wherein the second array may be an x*y array; wherein x > 2 and y > 2. A source of light comprising a plurality of solid state light sources configured in a second array may facilitate increasing the light intensity of the light emitted by the source of light. Further, a source of light comprising a plurality of solid state light sources may facilitate that the first beam of light may be generated from a larger light emitting surface.

[0111] In embodiments, each of the solid state light sources may (thus) comprise a light emitting surface. The light emitting surface may be that part of the solid state light source, wherein light leaves (and / or is emitted from) the solid state light source. In embodiments, the light emitting surface (of each of the solid state light sources) may have a largest dimension Ls. In embodiments, Lsmay be selected from the range of > 0.5 mm, such as from the range of > 0.75 mm, especially from the range of > 1 mm. Additionally or alternatively, Lsmay be selected from the range of < 30 mm, such as from the range of < 25 2024PF80273

[0112] 38 mm, especially from the range of < 20 mm. Further, (the light emitting surfaces of) the plurality of solid state light sources may be configured physically separated (from each other) in the second array. Especially, (the light emitting surfaces of) the plurality of solid state light sources may be configured physically separated (from each other) in the second array by a (smallest) edge-to-edge distance d2. In embodiments, the edge-to-edge distance d? may be selected from the range of > 0.6 mm, such as from the range of > 0.8 mm, especially from the range of > 1 mm. Additionally or alternatively, the edge-to-edge distance d? may be selected from the range of < 35 mm, such as from the range of < 30 mm, especially from the range of

[0113] < 25 mm. Further, in embodiments, d? > Ls(may apply), such as d? > 1.1 *LS, especially d? > 1.2*LS. Additionally or alternatively, d? < 5*LS(may apply), such as d? < 4*LS, especially d?

[0114] < 3*LS. Hence, in specific embodiments, each solid state light source may comprise a light emitting surface; wherein the light emitting surface may have a largest dimension Ls; wherein the plurality of solid state light sources may be configured physically separated in the second array by an edge-to-edge distance d?; wherein d? > Ls. Such a physical separation between solid state light sources in the second array may facilitate that, after distortion of the light by the optical element arrangement, the solid state light sources may (still) appear as separate light sources to an observer viewing the second array through the optical element arrangement. This may especially reduce the appearance of “bright spots” during operation of the light generating system, as the first beam of light may appear to be emitted as a plurality of separate, less bright, sub-beams from a plurality of solid state light sources, rather than a single high-brightness beam from a single (small) solid state light source.

[0115] In embodiments, the source of light (optionally comprising a plurality of solid state light sources) may be configured to generate a first beam of light. In embodiments, the light may be colored light, such as one (or more) of violet light, blue light, green light, yellow light, orange light, and red light. Alternatively, and especially, the light may be white light. The term “violet light”, and similar terms, may especially relate to light having a wavelength in the range of about 380-440 nm. The term “blue light”, and similar terms, may especially relate to light having a wavelength in the range of about 440-490 nm. The term “green light”, and similar terms, may especially relate to light having a wavelength in the range of about 490-560 nm. The term “yellow light”, and similar terms, may especially relate to light having a wavelength in the range of about 560-590 nm. The term “orange light”, and similar terms, may especially relate to light having a wavelength in the range of about 590-620 nm. The term “red light”, and similar terms, may especially relate to light having a wavelength in the range of about 620-780 nm. The term “white light”, and similar terms, herein, is known to the 2024PF80273

[0116] 39 person skilled in the art. It may especially relate to light having a correlated color temperature (CCT) between about 1800 K and 20000 K, such as between 2000 K and 20000 K, especially between 2700 K and 20000 K, for general lighting especially in the range of 2000-7000 K, such as in the range of 2700-6500 K. The CCT may especially be within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), especially within 10 SDCM from the BBL, such as within 5 SDCM from the BBL.

[0117] The first beam of light may be incident on (at least one) lens arrangement. Especially, the first beam of light may be incident on the cavity wall (of a lens arrangement). Hence, the central cavity (of a lens arrangement) may be configured in a light receiving relationship with the source of light. Further, the source of light may be configured to generate the first beam of light along an optical axis (Ao). In embodiments, the optical axis (Ao) may be configured intersecting the lens arrangement, such as especially the cavity wall and the lens arrangement second face. In specific embodiments, the optical axis (Ao) may be configured intersecting the lens arrangement apex. The optical axis (Ao) (of the first beam of light) may be configured parallel to the lens arrangement center axis (AL). Alternatively, the optical axis (Ao) (of the first beam of light) may be configured at a smallest mutual angle (ai) with the lens arrangement center axis (AL). In embodiments, the smallest mutual angle (ai) may be selected from the range of > 0°, such as from the range of > 1°, especially from the range of > 2°. Additionally or alternatively, the smallest mutual angle (ai) may be selected from the range of < 15°, such as from the range of < 10°, especially from the range of < 8°. Further, in embodiments, 0° < ai < 15° (may apply), such as 0° < ai < 10°, especially 1° < ai < 10°, like 2° < ai < 8°. Hence, in specific embodiments, the source of light may be configured to generate the first beam of light along an optical axis (Ao); wherein the optical axis (Ao) may be configured at a smallest mutual angle (ai) with the lens arrangement center axis (AL); wherein 0° < ai < 10°. Such an angle between the optical axis (Ao) and the lens arrangement center axis (AL) may facilitate that the source of light may emit the first beam of light towards the lens arrangement apex, thereby facilitating providing a symmetrical second beam of light (upon transmission through the optical element arrangement).

[0118] In embodiments, the first beam of light may have a first radiant intensity distribution (in a plane perpendicular to the optical axis (Ao) and in the angular range). The first radiant intensity distribution of the first beam of light may especially have a single peak (or maximum). That is, the radiant intensity of the first beam of light may be highest at a first angle (of 0°), wherein the radiant intensity may decrease with increasing angle (in every direction). In embodiments, the optical element arrangement may be configured to convert 2024PF80273

[0119] 40 the first beam of light into a second beam of light. Especially, the optical element arrangement may be configured to shape and / or diffuse the first beam of light into the second beam of light. In embodiments, the second beam of light may have a (second) radiant intensity distribution in a first plane (Pi). The first plane (Pi) may especially be configured perpendicular to the lens arrangement center axis (AL). Further, the (second) radiant intensity distribution (of the second beam of light) may comprise at least two peaks (or maxima). That is, the radiant intensity may have two angles for which applies that the radiant intensity may decrease with increasing angle (in every direction) from that starting angle.

[0120] Hence, the (second) radiant intensity distribution (of the second beam of light) may comprise at least two peaks, such as at least four peaks, especially at least six peaks. Additionally or alternatively, the (second) radiant intensity distribution (of the second beam of light) may comprise at most twelve peaks, such as at most ten peaks, especially at most eight peaks. Hence, the (second) radiant intensity distribution (of the second beam of light) may comprise a plurality of peaks. In embodiments, the plurality of peaks may each have the same radiant intensity. Especially, the second beam of light may have rotational symmetry of an order corresponding to the number of peaks in the radiant intensity distribution. For example, the radiant intensity distribution (of the second beam of light) may comprise two peaks, such that the second beam of light may have rotational symmetry of order 2 (i.e., the second beam may be mirror-symmetric). Alternatively, for example, the radiant intensity distribution (of the second beam of light) may comprise four peaks, such that the second beam of light may have rotational symmetry of order 4. In specific embodiments, the lens arrangements (of the optical element arrangement) may comprise the 12 cavity wall second sections as described above, wherein the central cavity may have an elongated shape in the central axis perpendicular cross-sectional view, wherein the 12 cavity wall second sections may comprise (i) two concave first cavity wall second sections, (ii) four concave second cavity wall second sections, (iii) two convex third cavity wall second sections, and (iv) four convex fourth cavity wall second sections (4224), and wherein the second beam of light may have a radiant intensity distribution comprising two peaks in the first plane (Pi). Alternatively, in specific embodiments, the lens arrangements (of the optical element arrangement) may comprise the 16 cavity wall second sections as described above, wherein the 16 cavity wall second sections may comprise (i) eight concave first cavity wall second sections, (ii) four convex second cavity wall second sections, and (iii) four convex third cavity wall second sections, (wherein the central cavity may have rotational symmetry of 2024PF80273

[0121] 41 order 4 about the lens arrangement center axis (AL),) and wherein the second beam of light may have a radiant intensity distribution comprising four peaks in the first plane (Pi).

[0122] In embodiments, the light generating system, such as especially the optical element arrangement, may comprise the first lens array as described above. Further, the light generating system may comprise a plurality of sources of light configured in a third array. The third array may especially be a (regular) n*m array. In embodiments, n > 1 (may apply), such as n > 2, especially n > 3. Additionally or alternatively, in embodiments, n < 20 (may apply), such as n < 18, especially n < 16. Further, in embodiments, m > n (may apply), such as m > (n+1), especially m > (n+2). Additionally or alternatively, in embodiments, m < (n+19) (may apply), such as m < (n+17), especially m < (n+15). The third array may comprise at least two sources of light. Hence, in embodiments, n + m > 2 (may apply), such as n + m > 4, especially n + m > 6. Additionally or alternatively, in embodiments, n + m < 40 (may apply), such as n + m < 36, especially n + m < 32. As indicated above, the optical element arrangement may comprise the first lens array (comprising u*v lens arrangements). In embodiments, u + v > 2 (may apply), such as u + v > 4, especially u + v > 6. Additionally or alternatively, in embodiments, u + v < 40 (may apply), such as u + v < 36, especially u + v < 32. In embodiments, the first lens array may comprise the same number of lens arrangements as the number of sources of light in the third array. Especially, the first lens array and the third array may comprise the same number of rows, and the same number of lens arrangements and sources of light (respectively) in said rows. Hence, in embodiments, the first lens array may be identical (in terms of pitch and number of objects) to the third array. In such embodiments, each lens arrangement (in the first lens array) may be configured in a light receiving relationship with one of the sources of light. In embodiments, the optical element arrangement may comprise the lens arrangement holder as described above, wherein the sources of light may be configured (mounted) on the lens arrangement holder (wherein each source of light may be at least partially configured in a central cavity of one of the lens arrangements). Alternatively, the light generating system may comprise one or more reflective cups (see below). Hence, in specific embodiments, the light generating system may comprise a plurality of sources of light configured in a third array; wherein the third array may be an n*m array; wherein n > 1 and m > n; wherein n + m > 4; wherein the optical element arrangement may comprise the first lens array; wherein u + v > 4; and wherein each lens arrangement may be configured in a light receiving relationship with one of the sources of light. Such a light generating system may facilitate that multiple sources of light and 2024PF80273

[0123] 42 multiple lens arrangements may be configured in a single lighting module (e.g. a luminaire), thereby increasing the light intensity obtainable with said lighting module.

[0124] As indicated above, in embodiments, the light generating system may comprise one or more reflective cups. Especially, in embodiments, the light generating system may comprise > 1 reflective cups, such as > 2 reflective cups, especially > 3 reflective cups. Additionally or alternatively, the light generating system may comprise < 100 reflective cups, such as < 75 reflective cups, especially < 50 reflective cups. In specific embodiments, the light generating system may comprise u*v reflective cups (i.e., one for each lens arrangement in the light generating system). Further, in specific embodiments, the light generating system may comprise the third array (of sources of light), wherein the light generating system may comprise n*m reflective cups (i.e., one for each source of light in the light generating system). In embodiments, u = n and v = m may apply, wherein each lens arrangement may be configured in a light receiving relationship with one of the sources of light, and wherein the light generating system may comprise one reflective cup for each set of a source of light and a lens arrangement. Each of the one or more reflective cups may comprise a reflective cup bottom face, and one or more reflective cup side faces. Further, in embodiments, each of the one or more reflective cups may be configured to host the (or a) source of light. Especially, in embodiments, the source of light may be configured mounted on the reflective cup bottom face. In specific embodiments, the reflective cup bottom face may comprise a printed circuit board (“PCB”), wherein the source of light may be configured mounted and electrically coupled with the PCB. Further, in embodiments, each of the one or more reflective cups may be configured to host at least one of the lens arrangements (of the optical element arrangement). In embodiments, the at least one of the lens arrangements may be configured mounted on the reflective cup bottom face. Alternatively, the at least one of the lens arrangements may be configured at least partially supported by the one or more reflective cup side faces. In specific embodiments, the one or more reflective cup side faces may comprise a lens arrangement recess, wherein the at least one lens arrangement may be configured supported by (and / or mounted into) the lens arrangement recess. Alternatively, the one or more reflective cup side faces may be configured tapering towards the reflective cup bottom face. In such embodiments, the one or more reflective cup side faces may taper such, that the one or more reflective cup side faces may be separated from each other by a distance of < DL towards the reflective cup bottom face. Hence, in such embodiments, the at least one of the lens arrangement may be configured suspended by the one or more reflective cup side faces (and physically separated from the reflector cup bottom face). Alternatively, as 2024PF80273

[0125] 43 indicated above, the at least one of the lens arrangements may be configured on (i.e., in physical contact with) the reflective cup bottom face. In such embodiments, the reflective cup bottom face may further comprise one or more reflective cup bottom face depressions, wherein the source of light may be configured (mounted) in the one or more reflective cup bottom face depressions (and wherein the one or more reflective cup bottom face depressions may comprise a PCB).

[0126] Each of the one or more reflected cups may be configured to reflect at least part of the light received by the reflective cup. Especially, the reflective cup bottom face and the one or more reflective cup side faces may be configured to reflect at least part of the light received by the reflective cup bottom face and the one or more reflective cup side faces, respectively. Especially, the one or more reflective cups may be configured to reflect > 70%, such as > 80%, especially > 90%, of the light received by the reflective cup. Further, the one or more reflective cups may be configured to reflect > 95%, such as > 98%, including (essentially) 100%, of the light received by the reflective cup. Alternatively, the one or more reflective cups may be configured to reflect < 99%, such as < 98%, especially < 95%, of the light received by the reflective cup. Hence, in specific embodiments, the light generating system may comprise one or more reflective cups; wherein each of the one or more reflective cups may be configured to (i) host the source of light and at least one of the lens arrangements and (ii) at least partially support the at least one of the lens arrangements; wherein each of the one or more reflective cups may be configured to reflect at least part of the light received by the reflective cup. A light generating system comprising one or more reflective cups may facilitate improving the efficiency of the light generating system, as a smaller percentage of light may be refracted into undesired directions and / or absorbed by a (non-reflective) cup. Further, a light generating system comprising one or more reflective cups may facilitate further steering the second beam of light.

[0127] As indicated above, the optical element arrangement may comprise the first lens array, wherein the first lens array may comprise u*v lens arrangements. Further, as indicated above, the lens arrangements may be configured physically separated in the first lens array. In such embodiments, the light generating system may comprise one or more further lens arrangements. In embodiments, the one or more further lens arrangement may be any lens arrangement known in the art. Further, in embodiments, the one or more further lens arrangements may be configured in a fourth lens array with the u*v lens arrangements. In such embodiments, the u*v lens arrangements of the first lens array may be configured (evenly) distributed throughout the fourth lens array. Alternatively, the u*v lens 2024PF80273

[0128] 44 arrangements of the first lens array may be configured in physical contact with each other, wherein the first lens array may be embedded (as a subarray) in the fourth lens array. In further embodiments, the fourth lens array may comprise a plurality of first lens arrays, wherein the plurality of first lens arrays may be configured (evenly or randomly) distributed throughout the fourth lens array. In embodiments, each of the lens arrangements and the further lens arrangements may be configured in a light receiving relationship with one of the sources of light in the light generating system. Hence, in embodiments, the fourth array may be identical (in terms of pitch and number of objects) to the third array.

[0129] The light generating system may be part of or may be applied in e.g. office lighting systems, household application systems, shop lighting systems, home lighting systems, accent lighting systems, spot lighting systems, theater lighting systems, fiber-optics application systems, projection systems, self-lit display systems, pixelated display systems, segmented display systems, warning sign systems, medical lighting application systems, indicator sign systems, decorative lighting systems, portable systems, automotive applications, (outdoor) (road) lighting systems, urban lighting systems, green house lighting systems, horticulture lighting, digital projection, or LCD backlighting. The light generating system (or luminaire) may be part of or may be applied in e.g. optical communication systems or disinfection systems.

[0130] Hence, in yet a further aspect, the invention also provides a lamp or a luminaire comprising the light generating system as defined herein. The luminaire may further comprise a housing, optical elements, louvres, etc.. The lamp or luminaire may comprise a housing enclosing the light generating system. The lamp or luminaire may comprise a light window in the housing or a housing opening, through which the system light may escape from the housing.

[0131] In yet a further aspect, the invention also provides a lighting fixture comprising the light generating system as defined herein. In yet a further aspect, the light generating system may comprise a device selected from the group of a lamp, a luminaire, or a lighting fixture, wherein the lamp, luminaire, or lighting fixture may comprise one or more elements of the light generating system, such as the optical element arrangement and / or the source of light, and the light generating system may further comprise e.g. a control system configured to control the device. The term “lighting fixture” may refer to a light emitting system like a moving head, a search light, a stage light, etc. Generally these fixtures may have various control options for changing one or more of the direction of the light (e.g. via gimbals or rotary stages), the beam angle / width (e.g. via zoom optics), the beam pattern (e.g. 2024PF80273

[0132] 45 via mechanical selection of a specific aperture that defines a virtual and patterned source for the further projection optics), the color of the light (e.g. via mechanical selection of a certain color filter), and of course the luminous flux, and mostly these are remotely controllable.

[0133] In yet a further aspect, the invention also provides a projection device comprising the light generating system as defined herein. Especially, a projection device or “projector” or “image projector” may be an optical device that projects an image (or moving images) onto a surface, such as e.g. a projection screen. The projection device may include one or more light generating systems such as described herein. Hence, in an aspect the invention also provides a lighting device selected from the group of a lamp, a luminaire, a lighting fixture, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system as defined herein. Further, in an aspect the invention provides a lighting device selected from the group of an automotive lighting device, comprising the light generating system as defined herein. Especially, in a further aspect, the invention provides a lighting device selected from the group of a lamp, a luminaire, a lighting fixture, a projector device, a disinfection device, a photochemical reactor, an automotive lighting device, and an optical wireless communication device, comprising the light generating system as defined herein. The lighting device may comprise a housing or a carrier, configured to house or support, one or more elements of the light generating system.

[0134] In specific embodiments, the light generating system may be applied in an office lighting system. The office lighting system may comprise floor lights, ceiling lights, downlights, luminaires, etc., suitable for applications in office environments. Especially, the office lighting system may comprise a ceiling light or a downlight. Hence, in a further aspect, the invention may provide an office lighting system comprising the light generating system as defined herein. Configuring the light generating system as part of an office lighting system may provide the benefit that the office lighting system may provide an even light distribution throughout an office space. Especially, ceiling lights and / or downlights comprised by an office lighting system may often be installed in a grid, wherein the light generating system may be configured to provide a second beam of light having a radiant intensity distribution comprising peaks at angles complementary to the grid, such that the ceiling lights and / or downlights may be spaced further apart (in the grid) while maintaining uniform illumination of the office space with a desired light intensity.

[0135] The terms “light” and “radiation” are herein interchangeably used, unless clear from the context that the term “light” only refers to visible light. The terms “light” and 2024PF80273

[0136] 46

[0137] “radiation” may thus refer to UV radiation, visible light, and IR radiation. In specific embodiments, especially for lighting applications, the terms “light” and “radiation” refer to (at least) visible light.

[0138] BRIEF DESCRIPTION OF THE DRAWINGS

[0139] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0140] Figs. 1 A-B schematically depict an embodiment of the optical element arrangement and the light generating system;

[0141] Figs. 2A-B schematically depict an embodiment of the lens arrangement;

[0142] Figs. 3 A-C and 4 schematically depict embodiments of the light generating system;

[0143] Figs. 5A-B schematically depict embodiments of the first lens array;

[0144] Fig. 6 schematically depicts an embodiment of the optical element arrangement comprising microlenses; and

[0145] Fig. 7 schematically depicts an embodiment of the lighting device. The schematic drawings are not necessarily to scale.

[0146] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0147] Fig. 1 schematically depicts an embodiment of the optical element arrangement 2000. The optical element arrangement 2000 may comprise a first lens array 500 (see e.g. Fig. 5A). Further, the first lens array 500 may comprises u*v lens arrangements 4000. In embodiments, u > 1 and v > 1 (may apply). For each lens arrangement 4000 may apply that the lens arrangement 4000 may comprise a light transparent material having a lens arrangement first face 4010 and a lens arrangement second face 4020 (see Fig. IB). The lens arrangement second face 4020 may especially be configured convex, and may comprise a lens arrangement apex 4021 (see Fig. IB). Further, the lens arrangement 4000 may comprise a lens arrangement center axis (AL) configured perpendicular to and intersecting the lens arrangement apex 4021 of the lens arrangement second face 4020. The lens arrangement 4000 may especially have a (maximum) lens arrangement height (HL) along the lens arrangement center axis (AL). Further, the lens arrangement first face 4010 may comprise a central cavity 4100 configured extending towards the lens arrangement apex 4021 over part of the lens arrangement height (HL). The central cavity 4100 may comprise a cavity wall 2024PF80273

[0148] 47

[0149] 4200. In at least one central axis parallel cross-sectional view of the central cavity 4100 (schematically depicted in Fig. 1B(I)), parallel to the lens arrangement center axis (AL), the cavity wall 4200 may comprise k cavity wall first sections 4210. In embodiments, k > 3 (may apply). Further, in embodiments, the k cavity wall first sections 4210 may be altematingly configured convex and concave. Fig. 1B(II) schematically depicts a second central axis parallel cross-sectional view of the central cavity 4100, wherein the cavity wall 4200 does not comprise k cavity wall first sections 4210, wherein k > 3. In at least one central axis perpendicular cross-sectional view of the central cavity 4100, perpendicular to the lens arrangement center axis (AL) (and near the lens arrangement first face 4010), the cavity wall 4200 may comprise n cavity wall second sections 4220. In embodiments, n > 6 (may apply). The n cavity wall second sections 4220 may especially be altematingly configured convex and concave.

[0150] The central cavity 4100 may have a cavity height (He) along the lens arrangement center axis (AL) (see Fig. IB). In embodiments, 0.3*HL < He < 0.95*HL (may apply). Further, the number n of cavity wall second sections 4220 may decrease along the cavity height He. This is schematically depicted in Fig. 1 A, wherein Figs. 1 A(I-IV) depict central axis perpendicular cross-sectional views (of the central cavity 4100) taken at different heights along the cavity height (He), wherein Fig. 1 A(I) depicts a central axis perpendicular cross-sectional view taken close to the lens arrangement first face 4010, and wherein going from Fig. 1 A(I) to Fig. 1 A(IV) each central axis perpendicular cross-sectional view is taken closer to the lens arrangement apex 4021. Especially, closest to the lens arrangement apex 4021 (i.e., in the central axis perpendicular cross-sectional view schematically depicted in Fig. 1 A(IV)), the cavity wall 4200 may comprise one cavity wall second section 4220 in a central axis perpendicular cross-sectional view (of the central cavity 4100). Said one cavity wall second section 4220 may especially be concave. In Fig. 1 A and Fig. IB, inflection points between concave and convex cavity wall sections are schematically depicted with filled black circles.

[0151] Further, the cavity wall 4200 may comprise (i) m cavity wall second sections 4220 in a first central axis perpendicular cross-sectional view, wherein m = 12 (schematically depicted in Fig. 1 A(I)); and (ii) n2 cavity wall second sections 4220 in a second central axis perpendicular cross-sectional view, wherein m = 8 (schematically depicted in Fig. 1 A(II)). In such embodiments, as may be inferred from the above, the second central axis perpendicular cross-sectional view may be taken closer to the lens arrangement apex 4021 than the first central axis perpendicular cross-sectional view. Further, in embodiments, n > 12 may apply. 2024PF80273

[0152] 48

[0153] Fig. 1 A especially depicts an embodiment (of the optical element arrangement 2000) wherein the cavity wall 4200 may comprise n cavity wall second sections 4220, and n = 12 (may apply) (see Fig. 1 A(I)). The cavity wall 4200 may have a cavity wall second curvature length Lc2 in the at least one central axis perpendicular cross-sectional view of the central cavity 4100 (for which n = 12 may apply). Further, the central cavity 4100 may have an elongated shape in the central axis perpendicular cross-sectional view. The elongated shape may have a first axis of elongation (Ai). Further, the n (wherein n = 12 may apply) cavity wall second sections 4220 may comprise (i) two concave first cavity wall second sections 4221, (ii) four concave second cavity wall second sections 4222, (iii) two convex third cavity wall second sections 4223, and (iv) four convex fourth cavity wall second sections 4224. Each of the concave first cavity wall second sections 4221 may have a primary second curvature length LC2,I along the cavity wall second curvature length Lc2. Further, each of the concave second cavity wall second sections 4222 may have a secondary second curvature length Lc2,2 along the cavity wall second curvature length Lc2. In embodiments, 5*LC2,2 < LC2,I < 8*LC2,2 and 0.2*Lc2 < LC2,I < 0.3*Lc2 (may apply). Further, the concave first cavity wall second sections 4221 may be configured on opposite ends of the cavity wall 4200 (in the central axis perpendicular cross-sectional view). Especially, the first axis of elongation (Ai) may be configured intersecting the concave first cavity wall second sections 4221. Further, each of the convex third cavity wall second sections 4223 may be configured between two concave second cavity wall second sections 4222. The convex third cavity wall second sections 4223 may have a minimum tertiary second radius of curvature R2,3. Further, the convex fourth cavity wall second sections 4224 may have a minimum quaternary second radius of curvature R2,4. In embodiments, R2.3 < R2,4 (may apply).

[0154] The central cavity 4100 may be mirror-symmetric in the central axis perpendicular cross-sectional view. Especially, the first axis of elongation (Ai) may define a first mirror plane (Pmi) of the central cavity 4100 (in the central axis perpendicular cross- sectional view). Further, the central cavity 4100 may have a second mirror plane Pm2) in the central axis perpendicular cross-sectional view. The second mirror plane (Pm2) may be configured perpendicular to the first mirror plane (Pmi) and intersecting a geometrical center of the central cavity 4100. Especially, the central cavity 4100 may further be configured symmetric about the second mirror plane (Pm2) in the central axis perpendicular cross- sectional view. The lens arrangement 4000 may have a maximum circular equivalent lens outer diameter DL in a plane perpendicular to the lens arrangement center axis (AL). 2024PF80273

[0155] 49

[0156] Fig. IB schematically depicts two central axis parallel cross-sectional views of the same lens arrangement 4000 depicted in Fig. 1 A. As indicated above, the lens arrangement second face 4020 may be configured convex (with respect to an outside observer). Especially, the lens arrangement second face 4020 may have a minimum radius of curvature Rmin. In embodiments, Rmin > 0.5*DL (may apply). Further, the lens arrangement second face 4020 may define at least part of a sphere. Especially, the lens arrangement second face 4020 may have a constant radius of curvature RL (along the lens arrangement second face 4020).

[0157] As indicated above, the cavity wall 4200 may comprise k cavity wall first sections 4210 in at least one central axis parallel cross-sectional view of the central cavity 4100. In embodiments, k < 9 (may apply). The k cavity wall first sections 4210 may comprise at least two convex cavity wall first sections 4211 and at least one concave cavity wall first section 4212. Further, the convex cavity wall first sections 4211 may have a minimum primary first radius of curvature Ri,i. Additionally, the concave cavity wall first section 4212 may have a minimum secondary first radius of curvature Ri,2. In embodiments, Ri,i < RI,2 (may apply). The cavity wall 4200 may have a cavity wall first curvature length Lei in the at least one central axis parallel cross-sectional view of the central cavity 4100. Further, the at least two convex cavity wall first sections 4211 may have a (combined) primary first curvature length Lci,i along the cavity wall first curvature length Lei. In embodiments, 0.4*Lci < Lci,i < 0.8*Lci (may apply). Additionally, the at least one concave cavity wall first section 4212 may have a (combined) secondary first curvature length LCI,2 along the cavity wall first curvature length Lei. In embodiments, 0.2*Lci < LCI,2 < 0.6*Lci (may apply). Further, in embodiments, Lci,i + LCI,2 = Lei (may apply).

[0158] Fig. IB further schematically depicts an embodiment of the light generating system 1000. The light generating system 1000 may comprise the optical element arrangement 2000 as described herein and a source 100 of light 101. At least one of the central cavities 4100 (of the u*v lens arrangements 4000) may be configured in a light receiving relationship with the source 100 of light 101. The source 100 of light 101 may be configured to generate a first beam 5 of light 101. Especially, the source 100 of light 101 may be configured to generate the first beam 5 of light 101 along an optical axis (Ao). Further, the optical element arrangement 2000 may be configured to convert the first beam 5 of light 101 into a second beam 6 of light 101. The second beam 6 of light 101 may have a radiant intensity distribution in a first plane (Pi) perpendicular to the lens arrangement center axis (AL). In embodiments, the radiant intensity distribution may comprise at least two peaks. 2024PF80273

[0159] 50

[0160] This is schematically depicted in Fig. 1B(II) with the outline of the second beam 6 of light 101 comprising two “lumps”, wherein the height of the “lump” with respect to the lens arrangement 4000 indicates an increase in radiant intensity. In embodiments, the at least one of the central cavities 4100 may at least partly host the source 100 of light 101. That is, in specific embodiments, the source 100 of light 101 may be at least partly configured in the central cavity 4100. Alternatively, the central cavity 4100 may not host the source 100 of light 101, yet the central cavity 4100 may be configured in a light receiving relationship with the source 100 of light 101. Especially, the cavity wall 4200 (of said central cavity 4100) may be configured to receive light 101 emitted by a source 100 of light 101, wherein said source 100 of light 101 may be configured upstream of the cavity wall 4200.

[0161] Fig. 2A schematically depicts a further embodiment of the optical element arrangement 2000, such as especially of the lens arrangement 4000. In embodiments, n > 16 may apply. Hence, as depicted in Fig. 2A, in embodiments, the cavity wall 4200 may comprise n cavity wall second sections 4220, wherein n = 16. Moving from the top left to the bottom right, Fig. 2A schematically depicts central axis perpendicular cross-sectional views (of the central cavity 4100) taken at different heights along the cavity height (He), wherein the top left figure in Fig. 2A depicts a central axis perpendicular cross-sectional view taken close to the lens arrangement first face 4010, and wherein going from the top left figure to the bottom right figure in Fig. 2A each central axis perpendicular cross-sectional view is taken closer to the lens arrangement apex 4021. Fig. 2B schematically depicts a more detailed view of a central axis perpendicular cross-sectional view of the central cavity 4100 (wherein n = 16), taken at the same height as the top left figure in Fig. 2A. The cavity wall 4200 may have a cavity wall second curvature length Lc2 in the at least one central axis perpendicular cross- sectional view of the central cavity 4100. Further, the n (wherein n = 16 may apply) cavity wall second sections 4220 may comprise (i) eight concave first cavity wall second sections 4221, (ii) four convex second cavity wall second sections 4222, and (iii) four convex third cavity wall second sections 4223. Each of the concave first cavity wall second sections 4221 may have a primary second curvature length LC2,I along the cavity wall second curvature length LC2. Further, the convex second cavity wall second sections 4222 and convex third cavity wall second sections 4223 may alternate along the cavity wall 4200. Each of the convex second cavity wall second sections 4222 may have a secondary second curvature length LC2,2 along the cavity wall second curvature length Lc2. Further, each of the convex third cavity wall second sections 4223 may have a tertiary second curvature length Lc2,3 2024PF80273

[0162] 51 along the cavity wall second curvature length Lc2. In embodiments, 1.6 < (Lc2,2 / Lc2,s) < 5.2 (may apply). Additionally, in embodiments, 0.6 < (LC2,I / Lc2,s) < 2.6 (may apply).

[0163] The central cavity 4100 may be mirror-symmetric in the central axis perpendicular cross-sectional view. Especially, the central cavity 4100 may be symmetric about a first mirror plane (Pmi) parallel to and intersecting the lens arrangement center axis (AL). Further, the central cavity 4100 may be symmetric about a second mirror plane (Pm2) configured perpendicular to the first mirror plane (Pmi) and intersecting the lens arrangement center axis (AL). Hence, the central cavity 4100 may have rotational symmetry of order 4.

[0164] Fig. 3 A schematically depicts a central axis parallel cross-sectional view of the lens arrangement 4000 of Fig. 2A-B. In Fig. 3A, the individual lengths of the (at least) two convex cavity wall first sections 4211 are indicated by references Lci,ia and Lci,ib. In embodiments, Lci,ia = Lci,ib may apply. Further, Fig. 3 A schematically depicts a further embodiment of the light generating system 1000 (comprising a source 100 of light 101). The source 100 of light 101 may comprise a plurality of solid state light sources 10 configured in a second array 600. The second array 600 may especially be an x*y array. In embodiments, x > 2 and y > 2 (may apply). Each solid state light source 10 may comprise a light emitting surface 15. The light emitting surface 15 may have a largest dimension Ls. Further, the plurality of solid state light sources 10 may be configured physically separated (from each other) in the second array 600 by an edge-to-edge distance d2, wherein d2 > Ls.

[0165] Fig. 3B schematically depicts a perspective view of the same lens arrangement 4000 as schematically depicted in Fig. 2A, Fig. 2B, and Fig. 3 A. As schematically depicted in Fig. 3B, the lens arrangement first face 4010 may comprise one or more first face slanted (and / or curved) sections, wherein the one or more first face slanted (and / or curved) sections may be configured at an angle with the lens arrangement center axis (AL). The lens arrangement first face 4010 may be configured in physical contact with the lens arrangement second face 4020 via the one or more first face slanted (and / or curved) sections.

[0166] Fig. 3C schematically depicts an embodiment of the radiant intensity distribution of the second beam 6 of light 101. Especially, Fig. 3C schematically depicts an embodiment of the radiant intensity distribution obtainable with the lens arrangement 4000 as schematically depicted in Fig. 2A, Fig. 2B, Fig. 3A, and Fig. 3B. In Fig. 3C, the radiant intensity distribution is depicted in a perspective view, wherein a larger protrusion (or “bump”) with respect to the source 100 of light 101 indicates a higher (radiant) intensity of the light 101, and wherein a smaller protrusion (or “valley”) indicates a lower (radiant) intensity of the light 101. As depicted in Fig. 3C, a lens arrangement wherein n = 16 may (in 2024PF80273

[0167] 52 combination with a source 100 of light 101) be configured to provide a second beam 6 of light 101 having a radiant intensity distribution (in the first plane (Pi)) comprising four peaks. Said second beam 6 of light 101 may especially have rotational symmetry of order 4.

[0168] Fig. 4 schematically depicts a perspective view of the light generating system 1000, indicating the relative positions of the source 100 of light 101 and the lens arrangement 4000 with respect to each other.

[0169] Fig. 5A schematically depicts an embodiment of the light generating system 1000 comprising a plurality of sources 100 of light 101 configured in a third array 700. The third array 700 may be an n*m array. In embodiments, n > 1 and m > n (may apply). Further, in embodiments, n + m > 4 (may apply). The optical element arrangement 2000 may comprise the first lens array 500. In embodiments, u + v > 3 (may apply). Further, the lens arrangement second faces 4020 of adjacent lens arrangements 4000 in the first lens array 500 may be configured in physical contact with each other. Especially, in embodiments, u + v > 4 (may apply). Further, each lens arrangement 4000 (of the first lens array 500) may be configured in a light receiving relationship with one of the sources 100 of light 101.

[0170] Fig. 5B schematically depicts a further embodiment of the light generating system 1000 comprising the first lens array 500. The lens arrangement 4000 may be configured physically separated in the first lens array 500. Further, the optical element arrangement 2000 may comprise a lens arrangement holder 2100. The lens arrangement holder 2100 may be configured to host the u*v lens arrangements 4000 (and to physically separate the u*v lens arrangements 4000). (Additionally or) alternatively, the light generating system 1000 may comprise one or more reflective cups 1100. Each of the one or more reflective cups 1100 may be configured to host the source 100 of light 101 and at least one of the lens arrangements 4000. Further, each of the one or more reflective cups 1100 may be configured to at least partially support the at least one of the lens arrangements 4000. In embodiments, each of the one or more reflective cups 1100 may be configured to reflect at least part of the light 101 received by the reflective cup 1100.

[0171] Fig. 5B further schematically depicts an embodiment of the optical element arrangement 2000 comprising a plurality of microlenses 90. The plurality of microlenses 90 may be configured on or comprised by (at least part of) one or more of the cavity wall 4200 and the lens arrangement second face 4020. Further, the microlenses 90 may have an equivalent circular microlens diameter Dmi. In embodiments, Di / Dmi > 10 (may apply). The plurality of microlenses 90 may be arranged in a microlens array 900. Further, the 2024PF80273

[0172] 53 microlenses 90 may be configured in physical contact with each other in the microlens array 900.

[0173] Fig. 6 schematically depicts a further embodiment of the optical element arrangement 2000, especially of the lens arrangement 4000, comprising a plurality of microlenses 90 arranged in a microlens array 900.

[0174] Fig. 7 schematically depicts an embodiment of a luminaire 2 comprising the light generating system 1000 as described above. Reference 301 indicates a user interface which may be functionally coupled with the control system 300 comprised by or functionally coupled to the light generating system 1000. Fig. 7 also schematically depicts an embodiment of lamp 1 comprising the light generating system 1000. Reference 3 indicates a projector device or projector system, which may be used to project images, such as at a wall, which may also comprise the light generating system 1000. In embodiments, the lighting device 1200 may be a lamp 1, a luminaire 2, a lighting fixture, a projector device 3, a disinfection device, or an optical wireless communication device. Fig. 7 further schematically depicts an embodiments of an outdoor light, or stage light, or stadium light. Fig. 7 also schematically depicts a vehicle, like an automobile, but this may also be a truck, a motor cycle, etc., with one or more automotive lighting devices 4, e.g. headlights. These automotive lighting devices 4 may also comprise the light generating system 1000 as described herein. Hence, Fig. 7 schematically depicts embodiments of a lighting device 1200 selected from the group of a lamp 1, a luminaire 2, a lighting fixture, a projector device 3, a disinfection device, a photochemical reactor, an automotive lighting device 4, and an optical wireless communication device, comprising the light generating system 1000 as described herein. Lighting device light escaping from the lighting device 1200 is indicated with reference 1201. Lighting device light 1201 may essentially consist of system light 1001, and may in embodiments be system light 1001. Reference 1300 refers to a space, e.g. a room. Reference 1305 refers to a floor and reference 1310 to a ceiling; reference 1307 refers to a wall.

[0175] The term “plurality” refers to two or more. The terms “substantially” or “essentially” herein, and similar terms, will be understood by the person skilled in the art. The terms “substantially” or “essentially” may also include embodiments with “entirely”, “completely”, “all”, etc. Hence, in embodiments the adjective substantially or essentially may also be removed. Where applicable, the term “substantially” or the term “essentially” may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%. The term “comprise” also includes embodiments wherein the term “comprises” means “consists of’. The term “and / or” 2024PF80273

[0176] 54 especially relates to one or more of the items mentioned before and after “and / or”. For instance, a phrase “item 1 and / or item 2” and similar phrases may relate to one or more of item 1 and item 2. The term “comprising” may in an embodiment refer to “consisting of’ but may in another embodiment also refer to “containing at least the defined species and optionally one or more other species”. Use of the verb “to comprise” and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0177] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0178] The devices, or systems may herein amongst others be described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation, or devices, or systems in operation. It should be noted that the above- mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0179] The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a system claim, enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. The invention also provides a control system that may control the device or system, or that may execute a mode of operation of the system. Yet further, the invention also provides a computer program product, when running on a computer which is functionally coupled to or comprised by the device, or system, controls one or more controllable elements of such device, or system. The invention further applies to a device, or system comprising 2024PF80273

[0180] 55 one or more of the characterizing features described in the description and / or shown in the attached drawings. The invention further pertains to a method comprising one or more of the characterizing features described in the description and / or shown in the attached drawings.

[0181] The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

Claims

2024PF8027356CLAIMS:

1. An optical element arrangement (2000) comprising a first lens array (500); wherein the first lens array (500) comprises u*v lens arrangements (4000), wherein u > 1 and v > 1; wherein for each lens arrangement (4000) applies: the lens arrangement (4000) comprises a light transparent material having a lens arrangement first face (4010) and a lens arrangement second face (4020); the lens arrangement second face (4020) is configured convex and comprises a lens arrangement apex (4021); the lens arrangement (4000) comprises a lens arrangement center axis (AL) configured perpendicular to and intersecting the lens arrangement apex (4021) of the lens arrangement second face (4020); wherein the lens arrangement (4000) has a lens arrangement height (HL) along the lens arrangement center axis (AL); the lens arrangement first face (4010) comprises a central cavity (4100) configured extending towards the lens arrangement apex (4021) over part of the lens arrangement height (HL); wherein the central cavity (4100) comprises a cavity wall (4200); in at least one central axis parallel cross-sectional view of the central cavity (4100), parallel to the lens arrangement center axis (AL), the cavity wall (4200) comprises k cavity wall first sections (4210), wherein k > 3; wherein the k cavity wall first sections (4210) are alternatingly configured convex and concave; and in at least one central axis perpendicular cross-sectional view of the central cavity (4100), perpendicular to the lens arrangement center axis (AL), the cavity wall (4200) comprises n cavity wall second sections (4220), wherein n > 6; wherein the n cavity wall second sections (4220) are alternatingly configured convex and concave, wherein the number n of cavity wall second sections (4220) decreases along the cavity height He; wherein closest to the lens arrangement apex (4021) the cavity wall (4200) comprises one cavity wall second section (4220) in a central axis perpendicular cross- sectional view; wherein said one cavity wall second section (4220) is concave.

2. The optical element arrangement (2000) according to any one of the preceding claims, wherein one or more applies of (i) n > 12; and (ii) the lens arrangement (4000) has a2024PF8027357 maximum circular equivalent lens outer diameter DL in a plane perpendicular to the lens arrangement center axis (AL); wherein the lens arrangement second face (4020) has a minimum radius of curvature Rmin; wherein Rmin > 0.5*DL.

3. The optical element arrangement (2000) according to any one of the preceding claims, wherein one or more applies of: (i) 16 < n < 32; (ii) the lens arrangement second face (4020) defines at least part of a sphere; and (iii) k < 9.

4. The optical element arrangement (2000) according to any one of the preceding claims, wherein the central cavity (4100) has a cavity height (He) along the lens arrangement center axis (AL); wherein 0.3*HL < He < 0.95*HL; wherein HL < 0.5*DL, wherein DL is as defined in claim 2.

5. The optical element arrangement (2000) according to any of the preceding claims, wherein the cavity wall (4200) comprises: (i) cavity wall second sections (4220) in a first central axis perpendicular cross-sectional view, wherein = 12; and (ii) n2 cavity wall second sections (4220) in a second central axis perpendicular cross-sectional view, wherein n2 = 8.

6. The optical element arrangement (2000) according to any one of the preceding claims, wherein the k cavity wall first sections (4210) comprise at least two convex cavity wall first sections (4211) and at least one concave cavity wall first section (4212); wherein the convex cavity wall first sections (4211) have a minimum primary first radius of curvature Ri,i; wherein the concave cavity wall first section (4212) has a minimum secondary first radius of curvature RI,2; wherein RI,2 < Ri,i.

7. The optical element arrangement (2000) according to any one of the preceding claims, wherein the cavity wall (4200) comprises n cavity wall second sections (4220), wherein n = 16; wherein the cavity wall (4200) has a cavity wall second curvature length Lc2 in the at least one central axis perpendicular cross-sectional view of the central cavity (4100); wherein the n cavity wall second sections (4220) comprise (i) eight concave first cavity wall second sections (4221); (ii) four convex second cavity wall second sections (4222); and (iii) four convex third cavity wall second sections (4223); wherein:2024PF8027358 each of the concave first cavity wall second sections (4221) has a primary second curvature length LC2,I along the cavity wall second curvature length Lc2; the convex second cavity wall second sections (4222) and convex third cavity wall second sections (4223) alternate along the cavity wall (4200); wherein each of the convex second cavity wall second sections (4222) has a secondary second curvature length LC2,2 along the cavity wall second curvature length Lc2; wherein each of the convex third cavity wall second sections (4223) has a tertiary second curvature length Lc2,3 along the cavity wall second curvature length Lc2; wherein 1.6 < (Lc2,2 / Lc2,s) < 5.2; and0.6 < (LC2,I / LC2,S) < 2.6.

8. The optical element arrangement (2000) according to claim 7, wherein the central cavity (4100) is mirror-symmetric in the central axis perpendicular cross-sectional view; wherein the central cavity (4100) is symmetric about a first mirror plane (Pmi) parallel to and intersecting the lens arrangement center axis (AL); wherein the central cavity (4100) is further symmetric about a second mirror plane (Pm2) configured perpendicular to the first mirror plane (Pmi) and intersecting the lens arrangement center axis (AL).

9. The optical element arrangement (2000) according to any one of the preceding claims 1-7, wherein the cavity wall (4200) comprises n cavity wall second sections (4220), wherein n = 12; wherein the cavity wall (4200) has a cavity wall second curvature length Lc2 in the at least one central axis perpendicular cross-sectional view of the central cavity (4100); wherein the central cavity (4100) has an elongated shape in the central axis perpendicular cross-sectional view; wherein the elongated shape has a first axis of elongation (Ai); wherein the n cavity wall second sections (4220) comprise (i) two concave first cavity wall second sections (4221); (ii) four concave second cavity wall second sections (4222); (iii) two convex third cavity wall second sections (4223); and (iv) four convex fourth cavity wall second sections (4224); wherein: each of the concave first cavity wall second sections (4221) has a primary second curvature length LC2,I along the cavity wall second curvature length Lc2; wherein each of the concave second cavity wall second sections (4222) has a secondary second curvature length Lc2,2 along the cavity wall second curvature length Lc2; wherein 5*Lc2,2 < LC2,I < 8*LC2,2 and 0.2*Lc2 < LC2,I < 0.3*Lc2;2024PF8027359 the concave first cavity wall second sections (4221) are configured on opposite ends of the cavity wall (4200); wherein the first axis of elongation (Ai) is configured intersecting the concave first cavity wall second sections (4221); and each of the convex third cavity wall second sections (4223) is configured between two concave second cavity wall second sections (4222); wherein the convex third cavity wall second sections (4223) have a minimum tertiary second radius of curvature R.2,3; wherein the convex fourth cavity wall second sections (4224) have a minimum quaternary second radius of curvature R.2,4; wherein R.2,3 > R.2,4.

10. The optical element arrangement (2000) according to any one of the preceding claims, wherein the optical element arrangement (2000) comprises a plurality of microlenses (90); wherein the plurality of microlenses (90) are configured on or comprised by one or more of the cavity wall (4200) and the lens arrangement second face (4020); wherein the microlenses (90) have an equivalent circular microlens diameter Dmi, wherein Di / Dmi > 10, wherein DL is as defined in claim 2; wherein the plurality of microlenses (90) are arranged in a microlens array (900); and wherein the microlenses (90) are configured in physical contact with each other in the microlens array (900).

11. The optical element arrangement (2000) according to any one of the preceding claims, wherein u + v > 3; wherein the lens arrangement second faces (4020) of adjacent lens arrangements (4000) in the first lens array (500) are configured in physical contact with each other.

12. A light generating system (1000) comprising the optical element arrangement (2000) according to any one of the preceding claims and a source (100) of light (101), wherein at least one of the central cavities (4100) is configured in a light receiving relationship with the source (100) of light (101); the source (100) of light (101) is configured to generate a first beam (5) of light (101); wherein the optical element arrangement (2000) is configured to convert the first beam (5) of light (101) into a second beam (6) of light (101); wherein the second beam (6) of light (101) has a radiant intensity distribution in a first plane (Pi) perpendicular to the lens arrangement center axis (AL); wherein the radiant intensity distribution comprises at least two peaks.2024PF802736013. The light generating system (1000) according to claim 12, wherein one or more applies of: the at least one of the central cavities (4100) at least partly hosts the source (100) of light (101); the source (100) of light (101) comprises a plurality of solid state light sources (10) configured in a second array (600); wherein the second array (600) is an x*y array; wherein x > 2 and y > 2; and the light generating system (1000) comprises one or more reflective cups (1100); wherein each of the one or more reflective cups (1100) is configured to (i) host the source (100) of light (101) and at least one of the lens arrangements (4000) and (ii) at least partially support the at least one of the lens arrangements (4000); wherein each of the one or more reflective cups (1100) is configured to reflect at least part of the light (101) received by the reflective cup (1100).

14. The light generating system (1000) according to any one of the preceding claims 12-13, comprising a plurality of sources (100) of light (101) configured in a third array (700); wherein the third array (700) is an n*m array; wherein n > 1 and m > n; wherein n + m > 4; wherein the optical element arrangement (2000) comprises the first lens array (500); wherein u + v > 4; and wherein each lens arrangement (4000) is configured in a light receiving relationship with one of the sources (100) of light (101).

15. A lighting device (1200) selected from the group of a lamp (1), a luminaire (2), a lighting fixture, a projector device (3), a disinfection device, a photochemical reactor, an automotive lighting device (4), and an optical wireless communication device, comprising the light generating system (1000) according to any one of the preceding claims 12-14.

Images