Optical beam shaper, projection device and method for constructing a plurality of condenser lenses

Abstract

An optical beam shaper for generating an emerging light beam from an incident light beam comprises a condenser lens array having a plurality of condenser lenses, the plurality of which are configured to receive the incident light beam; and a projection lens array having a plurality of which are configured to receive light from the condenser lens array and to emit the emerging light beam. A base surface of at least one first condenser lens of the condenser lens array has a non-rectangular shape; and in an adjacent region between the first condenser lens and an adjacent second condenser lens, a height profile of the first condenser lens is adapted to that of the second condenser lens.

Description

[0001] The present invention relates to an optical beam shaper for generating an emerging light beam from an incident light beam, to a projection device comprising such an optical beam shaper, and to a method for determining the shape of a plurality of condenser lenses (or converging lenses) that can serve, for example, as an optical beam shaper described herein. The present invention relates in particular to pattern generation based on maskless double-sided microlens arrays (MLAs) with arbitrarily shaped freeform lenslets and a high-efficiency rotary display projector with reduced stray light.

[0002] A multi-channel pattern projection approach based on the masked fly's eye condenser (FEC) [1] enables very compact projection systems with a homogeneous and sharp output pattern with a top hat profile. In such a projector, the input lenses act as condenser lenses, achieving Köhler illumination, i.e., they image the light source into the pupil of the addressed projector lenslet. Köhler illumination with a fully filled pupil is a prerequisite for étendue-preserving projection [2]. This allows for the smallest possible lateral extent of the projection system for the given target pattern. However, the use of an absorbing slide mask array drastically limits the system's transmission and therefore reduces the resulting brightness of the projected pattern.Additionally, the presence of the absorbent mask layer increases the number of steps in the replication process and thus increases manufacturing costs.

[0003] An FEC with input lenses 1002 with a base area of ​​the target pattern ( Fig. 14a) enables efficient pattern projection without the use of absorbing mask apertures, which significantly improves transmission and thus brightness, provided that the input array still has a 100% fill factor [3]. However, shaping the input lenslets 1002 with a simple spherical or aspherical profile in any way produces localized stray light features 1004 caused by edges 1008 of the lenslets 1002 that occur around the projected pattern 1006. An example of a projected pattern with rafter-shaped (or chevron) lenslets is shown in Fig. 14b given.

[0004] In other words, they show Fig. 14a and Fig. 14b Simple rafter-shaped entrance lenslets with spherical profile and a corresponding pattern with localized scattering features.

[0005] To suppress stray light in maskless MLA projection systems, some remaining absorbing masks 1012 can be positioned at a short distance (<< f, where f is the focal length of the lenslets) in front of or behind the input array [4]. This would block only the areas between the lenslets 1002 ( Fig. 15a). This will keep the brightness of the projected pattern constant, but significantly reduce stray light, at the cost of a slightly reduced size of the projected pattern ( Fig. 15b). Unfortunately, the use of an absorbing mask array increases the steps required for polymer-on-glass replication (current state of the art) and precludes the use of injection molding technology for mass production.

[0006] In other words, they show Fig. 15a and Fig. 15b simple rafter-shaped entrance lenses 1002 with remaining masks 1012 and a corresponding pattern 1006.

[0007] Another approach to reducing stray light in such systems is to decompose the shape of the input lenslets into elementary features 1002a and 1002b, which can be tiled with a 100% fill factor ( Fig. 16a). Their images can be controlled by output lenslets to form a desired pattern [5]. However, this does not guarantee that disturbing effects are avoided and can lead to the appearance of stray light on the output MLA. Additionally, this approach might require an effort to suppress visible seams or brightness levels between the elementary parts of the projected patterns ( Fig. 16b and Fig. 16c).

[0008] In other words, it shows Fig. 16a an arrangement of disassembled input lenses and Fig. 16b and Fig. 16c shows corresponding patterns.

[0009] DE 10 2017 004 562 A1 describes a method for manufacturing a microprojector for a projection display, wherein the microprojector comprises a carrier on which a projection lens array with a plurality of projection lenses is arranged, wherein an object structure array with a plurality of, in particular identical, object structures is arranged on a side of the carrier facing away from the projection lens array. At least one projection lens is assigned to each object structure such that the projections of the object structures by the projection lenses superimpose to form a complete image, wherein it is particularly provided that the distance between a projection lens and the assigned object structure corresponds to the focal length of the respective projection lens.

[0010] DE 10 2015 216 985 A1 describes a projection device with at least one light source and an arrangement of optical channels. Each channel consists of a first refractive freeform optical surface and a second refractive freeform optical surface, as well as an optical projection system. The first and second refractive freeform optical surfaces are arranged between the light source and the projection system and cause Köhler illumination of the projection system by means of a light object structure that generates the image to be projected onto an image surface of the projection system, with the images of the arrangement of optical channels overlapping.

[0011] Therefore, there is a need to improve the projection of patterns.

[0012] One object of the present invention is therefore to provide an optical beam shaper, a projection device and a method for determining the shape of condenser lenses that enable a high quality of the projected pattern while avoiding the disadvantages known from the prior art.

[0013] This problem is solved by the subject matter as defined in the independent claims.

[0014] One advantage of the present invention is that by avoiding abrupt changes in height or deflection (or sag) between the input lenslets, the generation of detrimental stray light can be minimized or even eliminated, thus rendering the complex arrangement of a light-suppression mask unnecessary, although it does not prevent the generation of stray light entirely. That is, as an alternative or in addition to known concepts, this generation of stray light can be avoided, thereby rendering conventional countermeasures for suppressing stray light unnecessary.

[0015] The inventors have determined that one source of scattered light is a deflection-height difference between condenser lenses, so that by avoiding the differences, at least in part, by applying the deflection profile or the height profile, a high quality of projection can be achieved.

[0016] The inventors have determined that one of the main problems of scattered light effects, which lead to a reduction in projection quality, is caused by deflection height jumps, i.e., optical edges through which incident light is deflected in an undesirable way.

[0017] One solution presented according to the exemplary embodiments consists of adapting the deflection-height profile, particularly for non-rectangular shapes of condenser lenses, in order to achieve adapted height profiles that make it possible to maintain or even avoid such scattered light and to have good imaging or projection quality, even without arranging an absorbing mask as implemented in the prior art, although the arrangement of such a mask is not prevented in the implementation of the present invention.

[0018] According to one embodiment, an optical beam shaper for generating an emerging light beam from an incident light beam comprises a condenser lens array with a plurality of condenser lenses, the plurality of which are configured to receive the incident light beam. A projection lens array of the optical beam shaper comprises a plurality of projection lenses configured to receive light from the condenser lens array and to emit the emerging light beam. A base surface of at least one first condenser lens of the condenser lens array has a non-rectangular shape, and in an adjacent region between the first condenser lens and an adjacent second condenser lens, the height profile of the first condenser lens is adapted to that of the second condenser lens.

[0019] According to one embodiment, a projection device comprises such an optical beam shaper and a light source configured to provide the incident light beam. The projection device may be, among other things, a headlight, e.g., a headlight beam of a vehicle or for a vehicle, but may also be a device usable for projecting a pattern, e.g., in a handheld device or a device installed in a mobile or stationary system.

[0020] Further embodiments relate to a method for determining a shape or layout of condenser lenses or entrance lenses based on fitting their height profile. Such a method comprises: determining a shape of a pattern to be projected by using the plurality of condenser lenses; and determining a height profile of the plurality of condenser lenses such that the height profiles of each condenser lens are fitted to (a) respective adjacent condenser lens(es).

[0021] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings, in which: Fig. Figure 1a shows a schematic side view of an optical beam shaper according to an exemplary embodiment; Fig. 1b an enlarged view of part of the condenser lens array from Fig. 1a shows; Fig. Figure 2 shows a schematic enlarged side view of a transition between condenser lenses according to an exemplary embodiment, which Fig. 1b may correspond; Fig. 3a shows a schematic top view of the base of the condenser lens according to an exemplary embodiment; Fig. 3b shows a schematic view to illustrate a light source obtained by a square LED and formed by a simple condenser lenslet with a spherical or aspherical profile, according to one embodiment; Fig. 4a shows a schematic top view of a rafter-shaped base of a condenser lens according to an embodiment; Fig. 4b a schematic representation of an array of condenser lenses according to Fig. 4a and an associated projection lens array; Fig. Figures 5a-b show a rafter-shaped input lenslet formed from two mirrored cylindrical parallelogram-shaped lenslets according to an embodiment and a schematic representation of the image of the source; Fig. Figures 6a-d show schematic representations relating to the effects of vertex position variations in condenser lenses using two mirrored anamorphic parallelogram-shaped lenslets, according to one embodiment; Fig. 7a shows a schematic diagram in which the distance between lenses is not optimized; Fig. 7b shows a representation that relates to Fig. 7a refers to, where the distance is optimized, according to an exemplary embodiment; Fig. Figures 8a-b show a deflection distribution map and a 3D appearance of the deflection-stepless array formed from rafter-shaped free-form input lenslets according to an embodiment; Fig. Figure 9 shows a schematic diagram of a projection obtained with condenser lenses, according to one embodiment; Fig. 10a-b show schematic representations of a design example for a condenser lens according to an embodiment, which has a more complex aperture shape with 8 corners; Fig. Figure 11a shows a schematic perspective view of an output lenslet array according to an exemplary embodiment; Fig. Figure 11b shows a representation of a resulting pattern projected to infinity with a single pre-collimated light source directed onto the array of Fig. 11a is applied; Fig. Figure 12 shows a schematic top view of an arrangement of two adjacent condenser lenses according to an embodiment, which has a continuous or steadily formed adjacent area; Fig. 13 shows a schematic flowchart of a process according to an exemplary embodiment; Fig. Figures 14a-b show schematic views of a known honeycomb condenser, FEC, with input lenslets having a base area of ​​the target pattern and an example of rafter-type lenslets; Fig. 15a-b show simple rafter-shaped entrance lenses with remaining masks and a corresponding pattern; Fig. Figure 16a shows an arrangement of disassembled input lenslets; and Fig. 16b-c patterns show the Fig. 16a.

[0022] Identical or equivalent elements, or elements with the same or equivalent functionality, are designated by the same or equivalent reference symbols in the following description, even if they appear in different figures.

[0023] The following description presents a number of details to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention can be implemented without these specific details. In other cases, known structures and devices are shown in block diagram form and not in detail to avoid obscuring embodiments of the present invention. Furthermore, features of the various embodiments described below can be combined unless expressly stated otherwise.

[0024] The embodiments described herein relate to arrays of lenses, in particular microlenses, also known as lenslets. Arrays of microlenses that can implement a condenser lens array or a projection lens array may be referred to as a microlens array (MLA). The advantageous modifications presented with reference to embodiments relate to the structure of the condenser lenses and / or the adaptation of their height profile to adjacent areas. According to one embodiment, such a structure is part of an optical beam shaper, while by incorporating a light source into such a beam shaper, a projection device can be obtained, which also falls within the scope of the embodiments described herein.

[0025] Fig. Figure 1a shows a schematic side view of an optical beam shaper 10 according to an exemplary embodiment. The optical beam shaper 10 is implemented to generate an emerging light beam 12 from an incident light beam 14. To implement this function, the optical beam shaper has a condenser lens array with a plurality of condenser lenses 181 to 18. n The condenser lens array 16 is configured to receive the incident light beam 14. The array can include a substrate 22 supporting one or more of the plurality of condenser lenses 18. Alternatively or additionally, the condenser lenses 18 can be formed as a single, integrated optical component, thereby also implementing the functionality of a substrate.

[0026] The optical beam shaper 10 further comprises a projection lens array 24, which includes a plurality of projection lenses 261 to 26. mexhibits, where the number m of projection lenses can be the same or different from the number n of condenser lenses. The projection lenses 261 to 26 m Projection lenses 26 can be formed on one side of the substrate 22 opposite the condenser lens array 16. The projection lenses 26 are configured to receive light from the condenser lens array 16 and to emit the emerging light beam 12. Optical components such as lenses, masks, substrates, and the like can be arranged between arrays 16 and 24, but can be an optional feature and thus omitted.

[0027] As in Fig. As shown in Figure 1a, both arrays 16 and 24 can be placed on a common substrate. Alternatively, arrays 16 and 24 can be placed on separate substrates, e.g., with an air gap between them.

[0028] The assignment between projection lenses 26 and condenser lenses 18 can be based on a 1:1 mapping, which can result in at least one or even every condenser lens 18 being assigned to exactly one projection lens 26. In another configuration, at least one condenser lens 18 can be assigned to more than one projection lens 26. Such a configuration can be caused, for example, by an inclination between arrays 16 and 26, or it can be based on an inclination that causes the two arrays to be non-parallel to each other. It may also be possible, based on the optical behavior of the condenser lenses 18 and / or on characteristics of the incident collimated beam, to illuminate more than one projection lens 26 with a single condenser lens 18. Such a configuration can be referred to as a 1:x configuration of condenser lenses (1) and projection lenses (x), where x > 1.This can cause an effect to occur intentionally that is usually avoided as crosstalk.

[0029] These configurations can be combined, for example, in different areas of the array 16 and / or 24. According to one embodiment, a single condenser lens 18 can be configured to illuminate more than one projection lens 26.

[0030] Fig. Figure 1b shows an enlarged view of part of the condenser lens array 16 by depicting, as a non-limiting example, two adjacent condenser lenses 18x and 18y that are abutting or touching each other or are arranged adjacent to each other on an adjoining region 28. On the adjoining region 28, a height profile of condenser lens 18x is fitted to a height profile of condenser lens 18y. Compared to a possible, but not necessarily planar, transition 32, optical surfaces 34x and 34y may still exhibit some small, but acceptable transitions, as shown in Fig. 1b shown. A preferred embodiment of the present invention consists in the fact that, for the adapted height profile, the adjacent area 28 has a deflection height jump of at most 30% of a total deflection profile height of the condenser lens 34x, a configuration which, in conjunction with Fig. 2 is described in more detail. In a preferred embodiment, the adapted height profile is a substantially stepless height profile between adjacent lenses of the plurality of condenser lenses 18 in the condenser lens array 16.

[0031] With renewed reference to Fig. 1a and Fig. In Figure 1b, the condenser lens 18, which has the adapted height profile, has a non-rectangular base. A base can be considered as a surface covered by the lens, e.g., an area on a substrate on which the lens is formed or created. In the case of a substrateless implementation, the aperture of the lens can be considered the base.

[0032] The base can be curved, for example, circular or elliptical, i.e., curved beyond manufacturing tolerances. Alternatively or additionally, a polygonal shape can form at least part of the base, with circular or curved parts and polygonal parts being combinable. In a preferred embodiment, the base is irregular. As an optional implementation, the base of the plurality of projection lenses 26 can follow the base of the plurality of condenser lenses of the condenser lens array 16. That is, the geometries of the bases can be similar or even identical.

[0033] Fig. Figure 2 shows a schematic enlarged side view of a transition between condenser lenses 34 x and 34 y , the Fig. 1b can correspond and form part of the condenser lens array 16 in the optical beam shaper 10. Although in an ideal profile of the optical surfaces of the condenser lenses the adjacent region 28 can have a lateral extent of nearly zero, according to a real profile 38 obtained through manufacturing processes and the like, the lateral extent of the adjacent region 28 is not zero and is determined by a parameter d in Fig. 2 indicated.

[0034] Within the adjacent area 28, although it might be preferred and in some embodiments even realized to have a deflection height difference or deflection height jump, or of essentially zero, i.e. without a jump, the height difference 42 in other embodiments may be at most 30% of a total deflection height profile height of the condenser lens 34. x and / or 34 yexhibit, preferably at most 20% or at most 15%. Preferably, such an adaptation is carried out between each pair of adjacently arranged condenser lenses, such that each condenser lens of the plurality of condenser lenses has a base surface with a non-rectangular shape and has a height profile that is adapted with respect to an adjacent condenser lens in a respective adjacent area.

[0035] In other words, according to one embodiment, an acceptable remaining deflection height jump 42 can be up to 30%, up to 15%, or even up to 5% of the total deflection profile of the microlens array, MLA. Alternatively or additionally, one shape of the deflection jump can have a flank angle Θ greater than 60°, preferably greater than 75°, and more preferably at least 89°. Alternatively or additionally, one radius of the tips can have a rounding or an inner radius r of at most 15 µm, preferably at most 10 µm, and more preferably at most 5 µm.

[0036] According to one embodiment, a deflection height jump slope 44 can be found in the adjacent area 28 between the condenser lenses 34. xand 34y are inclined at an angle Θ of at least 60°, preferably at least 70° and even more preferably at least 75° with respect to a surface of a substrate carrying the majority of condenser lenses 16, in order to conform to the adapted height profile. The steeper the slope 44, the less scattered light is to be expected.

[0037] The adjacent area 28 can have a lateral extension d along a direction from the first condenser lens 34 x to the second condenser lens 34 y (or vice versa) exhibiting at most 15% of a total extent of the condenser lens along a direction from a center of one of the condenser lenses 34 x to the center of the other condenser lens 34 yis to correspond to the adapted height profile. Preferably, d is less than 15%, e.g., at most 12% or at most 10%. Another parameter of the condenser lens array 16, which may be implemented in a manner at least influenced by the lateral extent d, is a so-called fill factor of the majority of condenser lenses 16 in the condenser lens array, which is at least 85%, preferably more, e.g., at least 88% or at least 90% or even more.

[0038] Alternatively or additionally, although this is optional, a rounding r in Fig. 2 of a form of condenser lens 34 x and / or 34 yand in the adjacent area 28 a radius of at most 15% of a total extent of the condenser lens along a direction from a center of the first condenser lens to a center of the second condenser lens, to conform to the fitted height profile. For the example, as an alternative, or at least part of a straight or planar flank 44, a radius or curvature can be implemented which nevertheless leads to a dead zone d.

[0039] Alternatively or additionally, the dead zone d is at most 15 µm, at most 10 µm, or at most 5 µm. As a further consideration, a remaining gap between microlenses, which may lead to a reduced fill factor, can be at most 15%, at most 10%, at most 5%, and most preferably at most 2% of the lateral extent between the centers of microlenses.

[0040] Embodiments of the present solution, which is the basis of the invention, can use arbitrarily shaped input lenslets with freeform profiles, such that at least a subset of the plurality of condenser lenses has a base surface with a freeform profile. Such a subset can be arranged as a cluster, i.e., in a common area. According to one embodiment, each of the condenser lenses of the condenser lens array is appropriately adapted. Adapting the height profile can eliminate, possibly completely, the sag-related height jumps, thereby drastically reducing straight line effects and enabling the projection of a pattern with sharper and cleaner contours compared to lenslets without an adapted height profile.Although the laborious use of absorbing masks is still possible to further improve quality, such use may be unnecessary considering the improvements obtained through the adapted height profile. The cost of making input lenses freeform could be degraded mapping of the source in the output lens plane and increased étendue; therefore, the solution may represent a compromise between direct light reduction and system étendue.

[0041] According to Fig. 3a and Fig. 3b presents an implementation that serves as a basis for some embodiments, wherein one, several, or each condenser lens represented by a condenser lens 18 of the condenser lens array has a rafter-shaped base, which is an example of an irregularly shaped base. Fig. Figure 3a shows a single lenslet 52 and an arrangement relative to the output lens 26 to avoid crosstalk, i.e., to keep an image of the source within a corresponding projection lenslet 26. The absence of another lenslet and the absence of an adjacent area to such an additional lenslet is illustrated. Fig. 3a no adapted elevation profile according to the exemplary embodiments.

[0042] A rafter can be considered to have at least two, or preferably exactly two, anamorphic surfaces 461 and 462 rotated within a parallelogram aperture. The anamorphic surfaces 461 and 462 can each, or both together, have a toroidal or biconical shape. That is, the anamorphic surfaces 461 and / or 462 can have a radius of curvature ROC that has a value other than 0 for one or both relevant directions x and y. Further explanations are given with respect to the base points T, U, P, and Q, where T and U can be reflected in a plane defined by a plane containing points Q and P, thereby defining points T1 and U1.

[0043] While Fig. Figure 3a shows a schematic top view of the base of the condenser lens 18. Fig. 3b shows a schematic view to show an image 47 of a light source, i.e. the source image, obtained by a square LED, and further shows a rectangularly shaped base of an output microlens 26.

[0044] To allow for a comparison with other embodiments described herein, we present Fig. 3a and Fig. Figure 3b presents an example with a simple rafter-like condenser lenslet 52 with spherical surface profiles, which generates deflection height jumps between such lenslets in the array, see Fig. 3a. In this case, the best imaging of the light source into the pupil of the projection lenslet is achieved, which helps to utilize the system étendue to its maximum or to maintain a sufficient safety distance to avoid unwanted crosstalk, see Fig. 3b. However, as previously described, changes in deflection height produce a pronounced localized scattered light.

[0045] In other words, it shows Fig. 3a a surface-spherical rafter-like entrance lenslet and Fig. Figure 3b shows a corresponding schematic representation of the source image, e.g., a square LED, which is covered within the extent of the output lenslet 26, ensuring the absence of unwanted crosstalk.

[0046] Fig. Figure 4a shows a schematic top view of a base surface of a condenser lens 40 according to an embodiment.

[0047] By referring to Fig. Section 4a describes advantageous parameters for reshaping the condenser lens 40, which enable a high degree of filling, e.g., approximately 100%, while also avoiding cracks in connection areas with other lenses. To illustrate this, Figure 4a shows... Fig. 4b A schematic view of a projection of a plurality of, e.g., six, projection lenses 261 to 266 in conjunction with an exemplary number of four condenser lenses 401 to 404. Additional condenser lenses, e.g., to obtain a 1:1 mapping between condenser lenses and projection lenses, may be included in the condenser lens array.

[0048] In Fig. 4a is one of four similarly shaped condenser lenses in Fig. 4b shows orientations of a radius of curvature ROCy, 48Y and orientations of a radius of curvature ROCx, 48X, i.e. radially along orthogonal directions X and Y with respect to the anamorphic surfaces 461 and 462. As shown in Fig. As shown in Figure 4b, at least a subset of the condenser lenses 26, which may, but not necessarily, be arranged as a cluster, has a congruent base area. At least for one arranged cluster, the condenser lenses can exhibit an adaptive height profile.

[0049] For stray light suppression with the input lenslet shape, the shape that Fig. As per section 14a, the deflection height jumps can be reduced or even completely eliminated, i.e., at least minimized. This can be implemented if the deflection value at two overlapping points of the adjacent contour of the lenslet is equal or within a tolerance range. This can be difficult if the lenslet 40 has a simple spherical or aspherical curvature profile. To overcome this, embodiments propose that the condenser lens 40 be designed as a freeform element with a single aperture, e.g., in a rafter-like contour, although other contours are not excluded. To achieve this, the condenser lens 40 can be designed as a combination of two mirrored anamorphic surfaces rotated within a single parallelogram-shaped aperture contour, the rotation being induced by an angle β in Fig. 4a is displayed.

[0050] In other words, they show Fig. 4a and Fig. 4b rafter-like entrance lenslets formed from two mirrored anamorphic surfaces rotated within a parallelogram-shaped aperture.

[0051] In a simple example, each of these two lenslets can be considered a cylindrical lens with a finite ROC. Y and an infinite ROX XIt can be implemented that are rotated by the same angle as the angle of the rafter, resulting in angles β and α being equal, i.e., β = α. In this case, the deflection can have the same value at all four points U, T, Q, and P, and it can also be equal between the lines U-P and T-Q. However, this can produce a solution where the mapping of the pre-collimated light source onto the output lenslet plane is affected by each such cylindrical input lenslet. This can be problematic for the normal operation of a honeycomb condenser and can lead to unwanted crosstalk, since the image of the pre-collimated light source may reflect the extent of the output lenslet due to a lack of focusing along the rotated X-direction, as shown in Fig. 5a and Fig. 5b shown, exceeds. Fig. Figure 5a shows a schematic top view of a base surface of a condenser lens 40', the base surface having the same or at least a similar shape to that shown in Figure 5a. Fig. The condenser lens 40 shown in 4a. Fig. The example shown in 5a defines a radius of curvature in the X-direction, ROC. x marked as 48 x to a value of 0. With an assignment of the projection lens 26, as in Fig. As shown in Figure 4b, an image 471 generated with the anamorphic surface 461 and / or an image 472 generated with the anamorphic surface 462 may extend beyond the possibly rectangularly shaped output microlens 26. This can be addressed, for example, by varying the distance between the lenses or arrays, by using a larger projection lens 26, or by other measures.

[0052] In other words, they show Fig. 5a and Fig. 5b a rafter-like input lenslet 40' formed from two mirrored cylindrical parallelogram-shaped lenslets 461, 462, and a schematic representation of the image of the source, e.g. a square LED, on the output lenslet 26, which leads to an undesired crosstalk, see Fig. 5b.

[0053] According to one embodiment, each of the anamorphic surfaces 461 and 462 can have a toroidal or biconical shape and / or can be shaped independently or differently from each other.

[0054] Compared to the one in Fig. 5a and Fig. In the embodiment shown in Figure 5b, which can be related to a simple implementation, with an intermediate implementation forming another example and relating to both parallelogram-shaped lenslets having a toroidal or biconical surface rotated at a certain angle, the following can apply. In the aforementioned case, the state of a completely stepless arrangement can be interpreted as having the same deflection between points U and T as well as between points P and Q, where the deflection may be the same for all four points, but need not be. Due to symmetry, if it is the same for U and T, and thus for U1 and T1, a corresponding adjacent region, which, for example, in the arrangement of Fig. 4b is designed to form a seamless arrangement with equal deflection at points P and Q, which can be part of an adjacent area along an orthogonal direction. This can be achieved with a specific combination of a rafter angle α, a surface rotation β, and m=ROCYROCX which represents a ratio between the radii of curvature of the anamorphic surface. For simplicity, a conic constant is chosen to be zero; however, the solutions given below are valid for non-zero conic values, particularly as long as conic is the same in the X and Y directions. It is preferred to keep conic zero in both directions as long as the numerical aperture NA of the input lenslet is less than 0.1. If the NA of the input lenslet is greater than 0.1, a non-zero conic constant should be used.

[0055] Furthermore, the adapted height profile can be implemented for more than two, in particular a plurality or even all, condenser lenses of the condenser lens array, where a single condenser lens can have adjacent regions with more than one, e.g., at least two, at least three, at least four, or even more lenslets, for example, when irregular pentagons, hexagons, and the like are used. Height profile adaptation can be implemented on more than one or even all of the adjacent regions. For example, a condenser lens sandwiched between two others, a second and a third condenser lens of the array, can provide a total of a first, second, and third condenser lens (and further lenses) adjacent in a first adjacent region and a second adjacent region.Optionally, the height of the first condenser lens can be different on the first and second sides, and adapted to the first adjacent area of ​​the second condenser lens and to the second adjacent area of ​​the third condenser lens. In other words, the height or curvature of the lens need not be of the same value or symmetrical on two or more sides of the lens, so that, for example, and with reference to . Fig. 8a Deflection values, e.g. on a positive and a negative side of the x-axis of a lenslet, which may differ from each other.

[0056] To achieve a completely deflection-height-stepless solution, the ratio between the radii m can be calculated as: m=2 tan2α+1−2tan2α(tan2α+1) Likewise, the rotation of the anamorphic surface β can be adjusted according to: β=90−arccos(1m+1)

[0057] The evaluation of the deflection at the specific XY coordinates, e.g. at the corners of the parallelogram-shaped aperture, can be carried out using the known deflection equation for biconical surfaces: z=cxx2+cyy21+1−(1+kx)cxx2−(1−ky)cyy2 where: z denotes the surface deflection; c x denotes the curvature in the X direction; c y denotes the curvature in the Y-direction; k x the conical constant in the X-direction is denoted and k y denotes the conical constant in the Y-direction.

[0058] The rotated coordinates can be used to calculate the deflection of the rotated biconical surface as follows: x'(x,y,β)=x cos(β)−y sin(β) y'(x,y,β)=x sin(β)+y cos(β) where: x & y - initial point coordinates; x' & y' - new point coordinates with applied rotation of the biconical surface β.

[0059] Naturally, the case of m = 1 can be excluded, as it leads to a simple non-anamorphic lenslet surface that cannot exhibit uniform deflection between the aforementioned points within the parallelogram-shaped aperture. It is preferred to choose relatively small values ​​for α, possibly, but not necessarily, within a tolerance range of, for example, 15%, 10%, or 5%, at most 35° (e.g., 25° in the given example). A small value of α can allow m to be as close to 1 as possible, which improves the imaging properties of the input lenses.

[0060] Alternatively, if one focuses on the specific relationship between the radii, then the possible maximum for the rafter angle α can be calculated as follows: α=arctan([1−m]cos(β)sin(β)sin2(β)+m cos2(β))

[0061] The imaging properties of the complete rafter-like freeform lenslet, which may comprise or consist of two anamorphic sub-lenslets configured as described above, also depend on the choice of the vertex position within the aperture. The in Fig. Examples 4a-6b show the case where the vertex is present for each of the two sub-lenslets; however, embodiments also refer to cases where better imaging of the pre-collimated light source is achieved by the complete rafter-like input lenslet when the vertex position is the same for both sub-lenslets, as in Fig. 6c-d shown. Nevertheless, the choice of the position of vertex(s) is free and does not affect the stepless arrangement, as long as this is symmetrical between the sub-lenslets, the anamorphic surfaces 48.

[0062] The described solution, completely free of deflection height jumps, can constitute one implementation of exemplary embodiments. However, deviations from the completely stepless solution also fall within the scope of protection of the invention, as described herein, e.g., with reference to Fig. 2.

[0063] In Fig. Figure 6a shows a schematic top view of a base surface of a condenser lens 40", which can be used in an optical beam shaper according to an exemplary embodiment. The anamorphic surfaces 481 and 482 can each have a vertex 521, 522, which, for example, are each located in a region of a center of the respective anamorphic surface 481, 482, resulting in separate images 471 and 472 in the representation of Fig. 6b leads.

[0064] Fig. Figure 6c shows a schematic top view of a base surface of a condenser lens 40"', which can be used as a condenser lens in an optical beam shaper according to one embodiment. As mentioned, within an identical condenser lens array 16, which is e.g. in Fig. As described in Figure 1a, the condenser lenses can have the same or different shapes, which also refers to the position of vertices 521 and 522 when the exemplary rafter shape is implemented. That is, different condenser lenses can be implemented, thus forming, for example, a combination of condenser lenses 40" and 40'''.

[0065] At the in Fig. In the example shown in Figure 6c, the respective vertices 521 and 522 of the anamorphic surfaces 481 and 482 are located in the adjacent region between the sub-lenslets 481 and 482, which is represented as a line 54 between points P and Q. More precisely, the vertices 521 and 522 can be located close to each other or even at the same point on line 54, which may allow images 471 and 472 to be joined, as in the corresponding representation of Figure 6c. Fig. 6d shown.

[0066] In other words, it shows Fig. 6a a rafter-shaped entrance lenslet 40" with individual vertices 521 and 522 of two sub-lenslets 481 and 482. Fig. Figure 6b shows a corresponding schematic representation of the image of the source, e.g. a square LED, on the output lenslet 26. Fig. Figure 6c shows a rafter-shaped entrance lenslet 40''' with a common vertex of two sub-lenslets 481 and 482 and Fig. Figure 6d shows a corresponding source image.

[0067] To avoid unwanted crosstalk, exemplary embodiments implement a precise selection of the position of the vertex(s) and / or a distance between the input and output lenslet planes in such a way, preferably such that the image of the pre-collimated light source is kept within the single channel, see Fig. 7a and Fig. Figure 7b shows a respective front view on an output microlens plane. In several embodiments, particularly with m << 1, optimizing the distance between the input and output lenses is of specific advantage or may even be necessary to achieve an optimal position where the beamlet extent is maximized for the given ROC. X and ROC Yis the least. In conjunction with exemplary embodiments, a beam, e.g., of light, can be understood as a cone of light obtained through a lens array described herein. A beamlet can be understood as light passing through a single channel. That is, a beam can be a total cone of light exiting the entire array, while a beamlet can be understood as a single cone of light exiting only one channel.

[0068] In other words, embodiments may involve optimizing the distance between the input or condenser lens and the output or projection lens to find a compromise between X and Y source imaging. Fig. Figure 7a shows a distance that is not optimized, and Fig. Figure 7b shows an optimized distance, where the source images are only schematically represented.

[0069] A width (W) and / or a height (H) of the rafter, as in Fig. As shown in Figure 4a, the stepless arrangement is not affected as long as the rafter angle α is not changed. Therefore, the choice of the specific values ​​for W and H is one degree of freedom if the required extent of the output lenslet is considered sufficient to completely cover the image of the pre-collimated light source within itself, see Figure 4a. Fig. 6b and Fig. 6d. Such a design approach, as described above, is now illustrated for a rafter with a width of, for example, W = 0.70 mm and a height H = 0.35 mm and an angle α of 25°.

[0070] The surface of one or each of the exemplary input sub-lenslets is a toroidal surface with m ≈ 0.40 and a rotation β ≈ 55°, see Fig. 4a. A deflection distribution map, which is in Fig. Figure 8a shows a schematic 3D representation of the array formed from the resulting rafter-shaped input lenslets, and a schematic representation of the array is shown in Figure 8a. Fig. Figure 8b shows that the modeling of the input microlens array is carried out taking into account typical manufacturing limitations in order to confidently account for the influence of the interlenslet regions on the scattered light [6]. It is evident that there are no deflection height jumps between adjacent lenslets.

[0071] In other words, they show Fig. 8a and Fig. 8b a deflection distribution map, see Fig. 8a, and a 3D appearance of the deflection-stepless array formed from rafter-shaped freeform input lenslets, Fig. 8b.

[0072] The output array or projection lens array can be made of rectangular output lenses, but they can also have the same rafter-like shape, for example, to follow the shape of the condenser lenses. However, it is advisable to choose the base area of ​​the output lens according to the exemplary embodiments and in such a way that it completely encloses the image of the pre-collimated light source formed by the rafter-shaped input lens on the plane of the output lens. The resulting projected pattern at 2 meters is shown in Fig. Figure 9 shows that there are no localized scattered light lines around the projected pattern, which is the result of the arrangement without any deflection height jumps.

[0073] In other words, it shows Fig. 9 a resulting projected pattern on a screen at a distance of 2 meters with a single applied pre-collimated light source, wherein a logarithmic scale 56 relating to an incoherent illuminance shows the high quality of the pattern.

[0074] More than one such pattern can be generated with the same pattern generator or optical beam shaper, provided that additional pre-collimated light sources are used in the system with an oblique illumination angle. In this case, crosstalk can be used in a controlled manner to generate the same pattern exactly adjacent to the original or at a distance [3], [4]. By appropriately controlling all pre-collimated light sources in the system, the dynamic function with projected patterns running in a sequence can be achieved. Exemplary embodiments provide an optical beam shaper or a projection device with an optical beam shaper that includes a control unit adapted to control the light source accordingly.

[0075] Further embodiments relate to deflection height jump suppression with polynomial freeform surfaces, which can be described as an advanced case.

[0076] The surface of the partial lenslet enclosed in the parallelogram-shaped aperture is rendered completely freeform. This can be achieved by optimizing the mapping of the input lenslet with additional criteria for the desired deflection value at the specific radial coordinates of the surface.

[0077] According to one embodiment, at least one of the condenser lenses used in an optical beam shaper has two adjacent anamorphic surfaces, each having a polynomial freeform surface shape. For example, such a surface can be represented as an extended polynomial surface type, where the deflection at any radial coordinate can be calculated as: z=cr21+1−(1+k)c2r2+∑i=1NAiEi(x,y) where: N denotes a number of polynomial coefficients in the series; A i & E i Let denote coefficients on the i-th extended polynomial term and r denote a radial coordinate. This specific case can refer to a complete condenser lens, regardless of whether it has a rafter shape or another base surface, where the condenser lens is realized as a freeform surface.

[0078] It may be preferable to use as few polynomial coefficients as possible during freeform surface optimization to avoid deflection oscillations. With high orders, it can be important to control the deflection values ​​not only at the aperture corners but also within the lines connecting these corners, since the deflection along two adjacent lines of two adjacent input lenslets might be distributed differently (e.g., between lines TQ and UP in [reference]). Fig. 6a and / or Fig. 6c). A standard point size can be chosen as an imaging optimization criterion. Alternatively, the total energy trapped within the area of ​​the output lenslet can serve as the optimization target. Advantageously, the use of a high-order freeform surface can allow more complex aperture shapes of the condenser lenslet, provided that the shape achieves a 100% condenser array fill factor or is at least close to 100%.

[0079] A design example of such a described approach is given for the input lenslets, which have a more complex aperture shape with 8 corners, as in Fig. Figures 10a-b illustrate a different irregularly shaped base surface of condenser lenses 40''''. A single lenslet 40'''' can be viewed as a combination of a twisted toroidal surface and two spherical surfaces shifted vertically in opposite directions, which can ensure the absence of deflection height jumps between resulting lenslets while forming an array. Fig. Figure 10a shows a deflection distribution diagram and in Fig. Figure 10b shows a 3D appearance of the deflection-stepless condenser lens array, which has a plurality of condenser lenses 40'''' each formed from freeform entrance lenslets with complex aperture shape having 8 corners.

[0080] In this particular case, due to a step-like structure of the resulting input array, output lenslets can preferably be arranged in the same way as in Fig. Figure 11a illustrates a schematic perspective view of a projection lens array 24' comprising a plurality of projection lenses 26'. To maintain high quality or even the best possible image of the pattern, the profile of the output microlenses can be retained as a simple spherical or aspherical surface, making slight deflection height jumps on the output side unavoidable but acceptable. Typically, deflection height jumps on the output side are considerably less critical than on the input side, as they do not lead to localized far-field scattering features [6]. The resulting projected pattern at infinity is shown in Fig. Figure 11b shows a light intensity scale. It can be seen that there are no localized scattered light lines around the projected pattern, which is a result of the deflection-height-stepless arrangement of input lenses. That is to say, Fig. Figure 11a shows a schematic perspective view of an output lenslet array according to an exemplary embodiment and Fig. Figure 11b shows a representation of a resulting pattern projected to infinity using a single applied pre-collimated light source.

[0081] Similarly, other complex pattern shapes (e.g., with more corners or smooth curved lines) can be achieved by optimizing the freeform profile of input lenses to balance deflection height jumps with the quality of the source images at the output array plane. The requirement for a crosstalk-free system is that the entire geometric extent of the source image formed by the freeform input lens must remain within the aperture of the corresponding output lens. Finally, controlled crosstalk can still be applied to generate more than one pattern using the same projection system.

[0082] Meanwhile, as described for the rafter-like structure, embodiments may refer to the use of two anamorphic surfaces having a shape according to the following: m=2 tan2α+1−2tan2α(tan2α+1) where m represents a ratio between different radii of the anamorphic surfaces (461, 462) along orthogonal directions x and y; where α is a rafter angle; β=90−arccos(1m+1) where β specifies a rotation angle by which the anamorphic surfaces are rotated; or α=arctan([1−m]cos(β)sin(β)sin2(β)+m cos2(β))

[0083] For the same, i.e., rafter-shaped or for other surfaces, an implementation of one or more condenser lenses could be applied according to exemplary embodiments, the condenser lens having at least two adjacent anamorphic surfaces, each having a shape as follows, wherein the first condenser lens has two adjacent anamorphic surfaces, each having a shape as follows: z=cr21+1−(1+k)c2r2+∑i=1NAiEi(x,y) where N is a number of polynomial coefficients in the series; A i & Ei coefficients on the i-th extended polynomial term are and r is a radial coordinate of z that specifies a surface deflection, and c is a curvature value.

[0084] In conjunction with the use of conical surfaces in any of the above cases or other cases in general, and as a basis for such considerations, a layout of the lenslets can be based on the following rule of determination: z=cxx2+cyy21+1−(1+kx)cxx2−(1−ky)cyy2 where z represents a surface deflection, c x specifies a curvature of the anamorphic surface along the direction x, c y specifies a curvature of the anamorphic surface along the direction y, k x specifies a conical constant in the x-direction; k y specifies a conical constant in the y-direction, and x'(x,y,β)=x cos(β)−y sin(β) y'(x,y,β)=x sin(β)+y cos(β) where x and y specify initial point coordinates and x' & y' specify new point coordinates with applied rotation of the biconical surface β; or α=arctan([1−m]cos(β)sin(β)sin2(β)+m cos2(β))

[0085] While some embodiments of the present invention have been described as having the adjacent area in such a way that it has a straight shape in a planar view, e.g. in conjunction with Fig. 3a, Fig. 4a, Fig. 5a, Fig. 6a, Fig. 6c, Fig. 8a and Fig. 10a, it is also possible to shape the adjacent region so that it has a continuous, i.e., continuously formed shape, or a shape corresponding to a periodic function such as a sine or cosine function. An example of a continuous or continuously formed adjacent region 28 is given in Fig. 12 shown, where the adjustment of the height profiles of the condenser lenses 181 and 182 is carried out, for example, according to Fig. 2a and / or according to a stepless implementation.

[0086] Fig. Figure 13 shows a schematic flowchart of a method 1300 according to an embodiment, which can be used to determine properties and / or a shape of condenser lenses according to an embodiment. That is, the method 1300 can be used to design one or more condenser lenses. Step 1310 includes determining a shape of a pattern to be projected by using the plurality of condenser lenses. Step 1320 includes determining a height profile of the plurality of condenser lenses, such that the height profiles of each condenser lens are adapted to each adjacent condenser lens.

[0087] It is noted that it is possible to distribute condenser lenses differently in the condenser lens array and, for example, by changing the projection direction of a projection lens or an optical channel thereof, a position of a condenser lens, so that it is possible to adjust the height profile also by taking into account a changed position of optical channels that are to overlap on the projected image.

[0088] Exemplary embodiments of the present invention can be used for various applications. For example, they can be used in automotive lighting and signaling systems, such as static or dynamic projecting turn signals, static or dynamic projecting reversing turn signals, or automotive low-beam headlights. Exemplary embodiments can also be used in various other fields of application, such as general lighting and projection applications, like stage lighting and / or architectural or industrial lighting.

[0089] Further embodiments of the present invention relate to a projection device, which may be adapted to a specific application as described herein. Such a projection device comprises an optical beam shaper described herein and a light source configured to provide the emerging light beam.

[0090] Although some aspects related to a device have been described, it is clear that these aspects also constitute a description of the corresponding process, where a block or device corresponds to a process step or a feature of a process step. Similarly, aspects described in connection with a process step also constitute a description of a corresponding block, element, or feature of a corresponding device.

[0091] The embodiments described above are merely illustrative of the principles of the present invention. It should be noted that modifications and variations of the arrangements and details described herein are obvious to other persons skilled in the art. Any limitation is intended to be limited only by the scope of the preceding claims and not by the specific details presented in the description and explanation of the embodiments herein. [1] M. Sieler, P. Schreiber, P. Dannberg, A. Bräuer and A. Tünnermann, “Ultraslim fixed pattern projectors with inherent homogenization of illumination,” Applied optics, vol. 51, pp. 64-74, 2012; https: / / doi.org / 10.1364 / AO.51.000064. [2] E. Geißler, “Meeting the challenges of developing LED-based projection displays,” Proc. SPIE 6196, Photonics in Multimedia, 619601 (April 21, 2006); https: / / doi.org / 10.1117 / 12.664031. [3] R. Kundu, D. Michaelis, P. Schreiber, et al., „Multi-aperture pattern projection using arbitrary shaped lenslets,“ Proc. SPIE 12666, (02.10.2023); https: / / doi.org / 10.1117 / 12.2675559. [4] R. Kundu, D. Michaelis, D. Stefanidi, et al., „Performance of UV-molded versus injection molded maskless microlens arrays for multi-aperture projection,“ Proc. SPIE 13021, Optical Fabrication and Testing VIII, 130210J (17 June 2024); https: / / doi.org / 10.1117 / 12.3016164. [5] P. Schreiber, R. Kundu, D. Michaelis, „Optischer Strahlformer und maskenloser Zeichenprojektor“, DE 10 2022 210 090 A1 (2024.03.28). [6] D. Stefanidi, L. M. Wilhelm, P. Schreiber, et. al., „Design of highly efficient far-field beam shapers with irregular maskless lenslet arrays,“ Appl. Opt. 63, 3046-3057, 2024 (https: / / doi.org / 10.1364 / AO.516730).

Claims

Optical beam shaper for generating an emerging light beam (12) from an incident light beam (14), wherein the optical beam shaper has the following features: a condenser lens array (16) comprising a plurality of condenser lenses (18, 34, 40; 40'; 40"; 40"'; 40""), wherein the plurality of condenser lenses (18, 34, 40; 40'; 40"; 40"'; 40"") is configured to receive the incident light beam; and a projection lens array (24) comprising a plurality of projection lenses (26) configured to receive light from the condenser lens array (16) and to emit the emerging light beam (12), wherein a base area of ​​at least one first condenser lens (34x) of the condenser lens array (16) has a non-rectangular shape;and wherein, in an adjacent area (28) between the first condenser lens (34x) and an adjacent second condenser lens (34y), a height profile of the first condenser lens (34x) is adapted to the second condenser lens (34y). Optical beam shaper according to claim 1, wherein the base surface is an irregularly shaped base surface. Optical beam shaper according to claim 1 or 2, wherein a base surface of the plurality of projection lenses (26) follows the base surface of the plurality of condenser lenses (18, 34, 40; 40'; 40"; 40"'; 40""). Optical beam shaper according to one of the preceding claims, wherein for the adapted height profile the first or second condenser lens (34x, 34y) has a deflection height jump of at most 30% of a total deflection profile height of the condenser lens (34). Optical beam shaper according to one of the preceding claims, wherein each condenser lens of the plurality of condenser lenses (18, 34, 40; 40'; 40"; 40"'; 40"") has a base surface with a non-rectangular shape and has a height profile adapted in relation to an adjacent condenser lens in a respective adjacent area (28). Optical beam shaper according to one of the preceding claims, wherein the adapted height profile is a substantially stepless height profile between adjacent lenses of the plurality of condenser lenses (18, 34, 40; 40'; 40''; 40'''; 40''''). Optical beam shaper according to one of the preceding claims, wherein the adjacent area (28) has a straight shape in a top view; or has a continuous shape or has a shape corresponding to a periodic function. Optical beam shaper according to one of the preceding claims, wherein at least a subset of the plurality of condenser lenses (18, 34, 40; 40'; 40''; 40''''; 40'''') have a congruent base area and / or are arranged as a cluster and have the adapted height profile within the cluster. Optical beam shaper according to one of the preceding claims, wherein the second condenser lens (34y) is adjacent to the first condenser lens (34x) at the adjacent region (28), which is a first adjacent region, and at a first side of the first condenser lens (34x); wherein a third condenser lens of the plurality of condenser lenses (18, 34, 40; 40'; 40''; 40'''; 40'''') is adjacent to the first condenser lens (34x) at a second adjacent region, which is arranged at another, second side; wherein a height profile of the first condenser lens (34x) is different at the first side and at the second side and is adapted to the second condenser lens (34y) at the first adjacent region; and to the third condenser lens at the second adjacent region. Optical beam shaper according to one of the preceding claims, wherein at least a subset of the plurality of condenser lenses (18) has a base surface having a rafter shape. Optical beam shaper according to claim 10, wherein the rafter shape has two or exactly two anamorphic surfaces (461, 462) rotated within a parallelogram aperture. Optical beam shaper according to claim 11, wherein the anamorphic surfaces (461, 462) have a toroidal or biconical shape. Optical beam shaper according to claim 11 or 12, wherein the two anamorphic surfaces (461, 462) have a shape according to: m = 2 tan 2 α + 1 − 2 tan 2 α ( tan 2 α + 1 ) where m is a ratio between different radii of the anamorphic surfaces (46 1 46 2 ) along orthogonal directions x and y; where α is a rafter angle; β = 90 − arccos ( 1 m + 1 ) where β gives an angle of rotation by which the anamorphic surfaces are rotated; or α = arctan ( [ 1 − m ] cos ( β ) sin ( β ) sin 2 ( β ) + mcos 2 ( β ) ) . Optical beam shaper according to one of the preceding claims, wherein the first condenser lens (34x) has two adjacent anamorphic surfaces (461, 462) each having a polynomial freeform surface shape. Optical beam shaper according to one of the preceding claims, wherein at least one or each condenser lens (18, 34, 40; 40'; 40"; 40"'; 40"") is assigned to exactly one projection lens (26); and / or wherein at least one condenser lens (18, 34, 40; 40'; 40"; 40"'; 40"") is assigned to more than one projection lens (26). Optical beam shaper according to one of the preceding claims, wherein at least a subset of the plurality of condenser lenses (18, 34, 40; 40'; 40"; 40"'; 40"") has a base surface with a freeform profile. Optical beam shaper according to one of the preceding claims, wherein a shape of the first condenser lens (34x) has a rounding in the adjacent area (28) having a radius (r) of at most 15% of a total extent of the condenser lens (34x) along a direction from a center of the first condenser lens (34x) to a center of the second condenser lens (34y) to conform to the adapted height profile. Optical beam shaper according to one of the preceding claims, wherein the adjacent area (28) has a lateral extent along a direction from the first condenser lens (34x) to the second condenser lens (34y) which is at most 15% of a total extent of the condenser lens along a direction from a center of the first condenser lens (34x) to a center of the second condenser lens (34y) to conform to the adapted height profile. Optical beam shaper according to one of the preceding claims, wherein a deflection height jump flank (44) between the first condenser lens (34x) and the second condenser lens (34y) is inclined by an angle of at least 60° with respect to a surface of a substrate which carries the plurality of condenser lenses (18, 34, 40; 40'; 40"; 40"'; 40"") to conform to the adapted height profile. Optical beam shaper according to one of the preceding claims, wherein a fill factor of the plurality of condenser lenses (18, 34, 40; 40'; 40"; 40"'; 40"") in the condenser lens array (16) is at least 85%. Optical beam shaper according to one of the preceding claims, wherein a shape of the base surface of the condenser lenses (18, 34, 40; 40'; 40"; 40"'; 40"") corresponds to a shape of a pattern that is projected using the projection lens (26). Projection device comprising the following features: an optical beam shaper according to one of the preceding claims, and a light source configured to provide the incident light beam (14). Method (1300) for constructing a plurality of condenser lenses, comprising the following steps: Determining (1310) a shape of a pattern to be projected by using the plurality of condenser lenses; and Determining (1320) a height profile of the plurality of condenser lenses such that the height profiles of each condenser lens are adapted to each adjacent condenser lens.

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