Optical system for automotive headlamps

Abstract

An optical system (1) for a headlamp of a motor vehicle comprises a condensing optics (2) formed by a matrix of condensing lenses (3) and arranged to focus an incident light beam (5). It further comprises at least one reflecting shield (9) arranged to reflect at least a subset of the focused light beam (10) and to produce a cutoff line (33) of an outgoing light beam (11). It further comprises an imaging optics (15) formed by a matrix of imaging lenses (16) arranged to project the focused light beam (10) and a reflected light beam (18) in front of the headlamp so that the reflected light beam (18) contributes to an intensity hot spot (34) on one side of the cutoff line (33).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an optical system for a headlamp of a motor vehicle. BACKGROUND

[0002] In the field of automotive lighting, in particular in headlamp solutions, different approaches for optical systems exist to realize low beam and high beam functionality. A low beam pattern is required to avoid blinding oncoming drivers. A reflector system using one reflector or a set of reflectors is a simple solution, however it has a considerable size and does not provide a sharp cut-off line. In contrast to the former approach, projector systems can have a more compact design. Typically, they use a single lens to produce a sharp cut-off line. But this traditional appearance design can still be optimized in its size. For example, a microlens array is very compact and has a minimum depth. An integrated chrome layer can produce a cut-off line. The disadvantage of this approach is that it requires complex and sensitive technology, resulting in an expensive end product. Furthermore, light is blocked by the chrome layer and can no longer be used for the main beam.

[0003] It is an object of the present invention to provide an optical system for automotive lighting which overcomes the above-mentioned disadvantages.

[0004] This object is achieved by the subject matter of the independent claims. Further developments and embodiments are described in the dependent claims. SUMMARY

[0005] In one embodiment, an optical system in a headlamp of a motor vehicle comprises a condenser optics formed by a matrix of condenser lenses arranged to focus an incident light beam. The optical system further comprises at least one reflective shield arranged to reflect at least a subset of the focused light beam and to produce a cut-off line of an outgoing light beam. Furthermore, the optical system comprises an imaging optics formed by a matrix of imaging lenses arranged to project the focused light beam and the reflected light beam in front of the headlamp such that the reflected light beam contributes to an intensity hotspot on one side of the cut-off line.

[0006] The matrix of condenser lenses can comprise only one single condenser lens such that a 1x1 matrix is formed. However, in a preferred embodiment, the matrix of condenser lenses comprises a plurality of condenser lenses. The condenser lenses are arranged in rows and / or columns. Each condenser lens can focus the incident light beam in a different way. For example, the condenser lenses can focus the incident light beam in different focal points and / or focal lines. Thus, the light distribution can be designed according to the requirements of road lighting. The light beam can also be referred to as light ray.

[0007] The at least one reflective shield can be arranged such that its main extension plane is perpendicular or approximately perpendicular to the main extension plane of the condenser lens matrix. However, different arrangements are equally possible. In case the optical system comprises more than one reflective shield, the reflective shields can be arranged parallel to each other. The reflective shields can have different shapes. The at least one reflective shield can be attached to the condensing optics by an adhesive.

[0008] The at least one reflective shield is provided to create a cutoff line of the exit light beam. The cutoff line can be a parallel or approximately parallel line with respect to the road surface. The reflective shield reflects a subset of the focused light beams that would otherwise be projected by the imaging optics outside the cutoff line, i.e. on the side of the cutoff line facing away from the road surface. The light beams are reflected at the main surface of the reflective shield.

[0009] The imaging lens matrix can comprise only one single imaging lens such that a 1x1 matrix is formed. However, in a preferred embodiment, the imaging lens matrix comprises a plurality of imaging lenses. The imaging lenses of the imaging lens matrix are arranged in rows and / or columns. The exit light beam is superimposed by the imaging optics. This means that, if the imaging lens matrix comprises more than one imaging lens, each imaging lens provides an image, wherein the respective images are superimposed.

[0010] The imaging optics projects the focused and reflected light beams below the cutoff line, i.e. on the side of the cutoff line facing the road surface. An intensity hot spot is created directly below the cutoff line, i.e. close to the cutoff line. The intensity hot spot is in particular generated by the reflected light beams that are projected by the imaging optics. However, light beams that are not reflected by the reflective shield can also contribute to the intensity hot spot. The hot spot is a region within the exit light beam distribution where the light intensity is higher compared to other regions. The focused and reflected light beams are projected by the imaging optics for road illumination. This means that the exit light beam is for road illumination.

[0011] The condensing optics, the reflective shield and the imaging optics are arranged such that the reflective shield can generate a sharp cutoff line, wherein the reflected light beams contribute to the intensity hot spot. The subset of the focused light beams that hits the reflective shield is not lost but can also be used for road illumination. This can save power consumption and contribute to the safety of road users. The road can be illuminated and oncoming drivers are not blinded.

[0012] The reflective shield can comprise a plastic material with a metallic coating. The reflective shield can also comprise a metal, e.g. aluminum or the like. The condensing optics and the imaging optics comprise a material that is transparent to light. Herein and in the following, “transparent” means a transparency of at least 80% or at least 90%. For example, the condensing optics and the imaging optics comprise glass. In another embodiment, the condensing optics and the imaging optics comprise a plastic material, such as polycarbonate (PC), polymethyl methacrylate (PMMA), silicone or epoxy. Thus, the condensing optics and the imaging optics can be manufactured by a molding technique like injection molding. Thus, their manufacturing can be cost-effective.

[0013] Each imaging lens of the imaging lens matrix can have a diameter of less than 5 mm. The depth of the imaging lens matrix can be less than 15 mm. Thus, the imaging lens matrix can be very compact. Advantageously, the size of the imaging lens matrix is smaller compared to conventional systems using one single imaging lens.

[0014] In an embodiment, at least one reflective shield is arranged between the condensing optics and the imaging optics such that the main extension plane of the condensing optics is substantially parallel to the main extension plane of the imaging optics and the main extension plane of the reflective shield is substantially perpendicular or transverse with respect to the main extension plane of the imaging optics.

[0015] The condensing lens matrix and the imaging lens matrix can be arranged such that their main extension planes are perpendicular or approximately perpendicular to the surface of the road. The at least one reflective shield can be attached to the condensing optics such that in a vertical direction, the reflective shield is arranged below a respective row of the condensing lens matrix. The vertical direction refers to a direction that is elongated perpendicular to the main extension plane of the reflective shield. In case the condensing lens matrix comprises more than one row, a further reflective shield can be arranged below each of said rows.

[0016] By this arrangement, a sharp cut-off line can be created, in which the reflected light beams contribute to an intensity hot spot. Thus, also a subset of the focused light beams that impinge on the reflective shield can be used for road illumination.

[0017] In an embodiment, the condensing lens matrix comprises a plurality of condensing lenses. The condensing lenses are arranged in rows and / or columns. For example, the condensing lens matrix is a 3x5 matrix comprising three rows and five columns of condensing lenses. Each condensing lens can focus an incident light beam on a different focal point or on a different focal line.

[0018] In an embodiment, the matrix of imaging lenses comprises a plurality of imaging lenses. The imaging lenses are arranged in rows and / or columns. For example, the matrix of imaging lenses is a 3x5 matrix comprising three rows of five imaging lenses. The number of rows of the matrix of imaging lenses can be equal to the number of rows of the matrix of condenser lenses. Each imaging lens projects a subset of the focused and reflected light beam in front of the headlamp for road illumination. This means that each imaging lens is arranged to generate an image. The images are at least partially superimposed such that the desired light distribution is generated.

[0019] In an embodiment, each of the imaging lenses is assigned to one of the condenser lenses such that a respective channel of the light beam within the optical system is formed. This means that each imaging lens at least partially projects a subset of the light beam that is focused by the respective condenser lens to which the imaging lens is assigned. Each imaging lens can be assigned to its own condenser lens and vice versa. However, it is also possible to assign several imaging lenses to the same condenser lens or to assign several condenser lenses to the same imaging lens. The imaging lenses of a particular row of the matrix of imaging lenses can be assigned to the condenser lenses of the corresponding row of the matrix of condenser lenses.

[0020] The light beam emitted from the condenser lens that reaches one respective imaging lens forms a channel of the light beam. Different channels of the light beam do not interfere with each other or only slightly interfere with each other. Thus, the light beam can be optically controlled in an efficient manner.

[0021] According to another aspect of the present invention, there is a vertical offset between the imaging lenses and the respective condenser lenses to which the imaging lenses are assigned.

[0022] This means that the vertical positions of the centers of mass of the imaging lenses and the corresponding condenser lenses can be different. Due to this arrangement, only a first subset of the focused light beam can reach the imaging optics for further projection. A second subset of the light beam that would be projected beyond / above the cut-off line is prevented from reaching the imaging optics. However, the condenser lenses can also be designed such that a large portion of the focused light beam is directed to the imaging lens optics.

[0023] In another embodiment, the optical system further comprises at least one absorptive shield arranged between the condenser optics and the imaging optics. The at least one absorptive shield is arranged to prevent cross-talk between the channels of the light beam.

[0024] The at least one absorptive shield can comprise an opaque material. In other words, the absorptive shield does not transmit light. For example, the at least one absorptive shield comprises an opaque plastic material. The at least one absorptive shield can be attached at a first side on the reflective shield and at a second side on the imaging optics by an adhesive. The first side of the absorptive shield can be attached on the back side of the reflective shield which is arranged between two respective rows of the condenser lens matrix. The second side of the absorptive shield can be attached on the imaging optics between two corresponding rows of the imaging lens matrix.

[0025] The at least one absorptive shield can prevent cross-talk between the focused light beams of different rows of the condenser lens matrix. Light beams focused by the condenser lenses in a lower row of the condenser lens matrix and / or reflected by the respective lower reflective shield are prevented from reaching the light beam channels of an upper row, and vice versa. This additionally ensures that only those light beams which are assigned to a respective condenser lens focus are projected by one of the imaging lenses. In other words, the at least one absorptive shield optically separates respective rows of light beam channels corresponding to rows of the condenser lens matrix and the imaging lens matrix, respectively. Further absorptive shields can optically separate further rows from each other. Thus, the light beams can be further optically controlled by means of the at least one absorptive shield. Furthermore, the absorptive shield can also serve as an alignment structure to align the condenser optics perpendicularly to the imaging optics.

[0026] In some embodiments, the focal plane of the condenser optics at least approximately matches the focal plane of the imaging optics. This means that the condenser optics focus the incident light beams onto the focal plane of the imaging optics.

[0027] Each of the condenser lenses within the condenser lens matrix can have its own focal point or focal line, respectively. However, the focal points and / or focal lines form a common focal plane. Thus, the focal points of the imaging lenses within the imaging lens matrix form a common focal plane which usually matches the focal plane of the condenser optics. This ensures that a clear image of the used light source is projected in front of the headlamp and the main illumination field is uniformly bright.

[0028] As mentioned above, the condenser lens matrix can comprise a plurality of condenser lenses. In some embodiments, at least one condenser lens of the condenser lens matrix is formed as an axially symmetric lens such that a main surface of the respective condenser lens approximates a spherical, elliptical or parabolic surface. For example, each of the condenser lenses within the condenser lens matrix forms an axially symmetric lens. Advantageously, almost any conventional lens design can be used for manufacturing such a condenser lens matrix. The main surface is the surface of the condenser lens at which the light beams are refracted. The main surface can face the imaging optics.

[0029] As an alternative or in addition to such embodiments, at least one of the condenser lens of the condenser lens matrix is formed as a segment of an axially symmetric lens, such that the main surface of the respective condenser lens approximates a slice from a spherical, elliptical or parabolic surface. For example, each of the condenser lenses within the condenser lens matrix is formed as a segment of an axially symmetric lens. In cross-section, such a segment can be formed as a segment of a Fresnel lens. This means, for example, that only half of an axially symmetric lens is used. With such a design, the light beams can be guided along a main direction. By way of example, the incoming light beams are focused in a downward direction. This helps to ensure that all incoming light beams can be used for road illumination.

[0030] As an alternative or in addition to the above embodiments, at least one of the condenser lenses of the condenser lens matrix is formed as an anastigmatic lens, in particular a cylindrical lens or a segment of a cylindrical lens. For example, the condenser lens matrix is formed by multiple rows of condenser lenses, wherein at least one row is formed by segments of a cylindrical lens. In this case, the imaging lenses of a respective row of the imaging lens matrix are assigned to the same condenser lens. Such a design is useful for providing a wide field of illumination.

[0031] In a further alternative to or in addition to the above embodiments, at least one of the condenser lenses of the condenser lens matrix comprises a main surface formed as a freeform surface. This means that the main surface can comprise protrusions, grooves and / or pits. Advantageously, the main surface of the condenser lens can be adapted to meet the specifications of road illumination.

[0032] In some embodiments, the condensing optics are configured such that its focal plane is between the imaging optics and the edge of the at least one reflective shield facing the imaging optics. The focal plane can be closer to said edge.

[0033] The edge of the reflective shield can be formed mainly by a straight line. The focal plane of the condensing optics can be in the vicinity of the edge of the reflective shield facing the imaging optics. The closer the edge of the reflective shield is to the focal plane of the condensing optics, the more paraxial rays are reflected such that the cutoff line is closer to the road. Such an arrangement can be used to implement the low beam function of the headlamp. Conversely, the further the reflective shield is from the focal plane, the higher the cutoff line. Such an arrangement can be used to implement the high beam function of the headlamp.

[0034] In some embodiments, the optical system comprises multiple reflective shields as described above. This means that all features disclosed for at least one reflective shield are also disclosed for each reflective shield comprised by the multiple reflective shields. In particular, each reflective shield is arranged to produce a cutoff line of the outgoing light beam. The cutoff line is produced by means of the imaging optics in superimposing the images of the reflective shields. Furthermore, the reflective shields are arranged to reflect at least a subset of the focused light beams such that the reflected light beams contribute to an intensity hotspot on the road-facing side of the cutoff line.

[0035] As mentioned above, the reflective shields can be arranged parallel to each other. The reflective shields can be attached to the condensing optics such that, in the vertical direction, the reflective shields are arranged below respective rows of the condensing lens matrix. Thus, each reflective shield can be assigned to a respective row of the condensing lens matrix. In other words, the same reflective shield is assigned to several condensing lenses within a row of the condensing lens matrix.

[0036] Respective edges of different reflective shields facing the imaging optics can have different distances to the focal plane of the condensing optics. Thus, both the near-field and the far-field function can be realized by the same optical system or by different modules of the optical system.

[0037] In some embodiments, at least one of the plurality of reflective shields comprises a kink at an edge facing the imaging optics. For example, the kink comprises a recess, a cut-out or a gap in the reflective shield at said edge. This can mean that the kink penetrates the reflective shield from its main surface to its backside. However, it is equally possible that the kink comprises a protrusion or a bump. The reflective shield can comprise more than one kink. Each kink can be assigned to one of the beam channels.

[0038] Due to the kink, a part of the reflective shield is further away from the focal plane of the condensing optics. As mentioned above, this influences the light distribution of the exit beam: At the area of the reflective shield where the kink (e.g. the recess / cut-out) is present, light rays are not reflected. Rather, these light rays are projected by the imaging optics above the cut-off line. This makes it possible to adjust the light distribution in the respective area. This can be advantageous, for example, in order to illuminate the right-hand side of the road in a way that road signs are more easily visible. Thus, the right-hand side of the road can be illuminated above the cut-off line. However, the left-hand side of the road needs to be illuminated such that oncoming drivers are not dazzled. Here, the light beam can not project above the cut-off line.

[0039] According to another aspect of the present disclosure, the optical system further comprises a collimating optics for providing a collimated incident light beam. In embodiments, the collimating optics comprises a light source. In embodiments, the collimating optics further comprises a collimating lens. The collimating lens is arranged between the light source and the condensing lens matrix. The condensing lens matrix is arranged between the collimating lens and the imaging lens matrix.

[0040] The light source can be any conventional light source. For example, a light emitting diode (LED) or an array of light emitting diodes can be used as the light source. Other light sources are equally possible. The collimating lens can comprise a transparent material, such as glass or plastic. In case a plastic material is used, the collimating lens can advantageously be formed by a molding technique, such as injection molding. Thus, the manufacturing costs are low. Typically, the collimating lens narrows the light beam such that the propagation direction becomes more aligned in a certain direction. For example, the collimating lens aims to produce parallel light rays.

[0041] In some embodiments, the collimating lens is integrated in the condensing optics. The collimating lens is arranged on a back side of the condensing optics facing the light source. The condensing lens matrix is arranged on a front side of the condensing optics facing the imaging optics. This means that the collimating lens and the condensing lens matrix form part of the optical system. In particular, the collimating lens and the condensing lens matrix comprise the same material, such as a plastic material. The collimating lens and the condensing lens matrix can both be formed in the same step of the manufacturing process, which further reduces the production costs.

[0042] In some embodiments, the imaging lenses of the imaging lens matrix are separated by a grid of additional absorbing shields. The grid of additional absorbing shields is provided to prevent cross-talk between the exit light beams. This means that there is an additional absorbing shield between two neighboring imaging lenses within the imaging lens matrix. The absorbing shield comprises an opaque material, such as a plastic material.

[0043] For example, the grid of additional absorbing shields is manufactured by injection molding to form a holder. Then, the individual imaging lenses are inserted into the grid in order to form the imaging lens matrix. In this case, the imaging lenses and the grid of additional absorbing shields are separate parts that are assembled.

[0044] Alternatively, the imaging lens matrix is formed by a single transparent substrate that is molded into the desired shape such that a plurality of imaging lenses is formed. Then, the grid is generated by overmolding the substrate with an opaque material. In this case, the imaging lens matrix and the grid form part of the optical system. In this approach, the manufacturing costs are relatively low. BRIEF DESCRIPTION OF DRAWINGS

[0045] The following description of the drawings can further illustrate and explain aspects of the optical system. Components and parts of the optical system that are functionally the same or have the same effect are denoted by the same reference signs. Identical or effectively identical components and parts can be described only with respect to the figure in which they appear first. Their description is not necessarily repeated in the consecutive figures.

[0046] Figure 1 Examples of the optical system are shown.

[0047] Figure 2Another example of an optical system is shown.

[0048] Figure 3 Another example of an optical system is shown.

[0049] Figures 4a-4c show examples of condenser lens matrices in optical systems.

[0050] Figure 4d shows another example of a condenser lens matrix in an optical system.

[0051] Figures 5a and 5b show examples of imaging lens matrices for optical systems.

[0052] Figures 6a-6b show examples of optical systems including collimating optics.

[0053] Figures 7a-7c show examples of light distribution in an optical system. Detailed Implementation

[0054] Figure 1 An example of optical system 1 is shown in cross-section. Optical system 1 can be used in the headlights of motor vehicles. Figure 1 The optical system 1 includes a focusing optics 2 formed by a focusing lens matrix 3. In this case, the focusing lens matrix 3 includes a focusing lens 4. The focusing optics is configured to focus an incident beam 5. The focusing optics 2 is configured to focus the incident beam 5 at a focal point 6 of the focusing optics 2. The incident beams are collimated, i.e., parallel to each other. The focusing optics 2 includes a rear side 7 facing the incident beam 5. The focusing optics also includes a main surface 8 facing the focal point 6, at which the incident beam 5 is refracted. Figure 1 In the example, the condenser lens 4 is formed as a segment of an axisymmetric lens, such that the main surface of the condenser lens approximates a slice from a spherical, elliptical, or parabolic surface.

[0055] according to Figure 1 The optical system 1 also includes a reflective shield 9. The main extending plane of the reflective shield 9 is generally perpendicular to the main extending plane of the condenser lens matrix 2. In the vertical direction z, the reflective shield is positioned below the condenser lens 4. The vertical direction z refers to the direction perpendicular to the main extending plane of the reflective shield 9.

[0056] The reflective shield 9 is arranged to reflect at least a subset of the focused light beams 10. The focused light beams 10 that are reflected at the reflective shield 9 are referred to as reflected light beams 18. The reflective shield 9 is further arranged to create a cutoff line 33 (not shown) of the outgoing light beams 11. The cutoff line 33 refers to a line above which in the vertical direction z no or relatively little outgoing light beams 11 are projected for illuminating the road. The subset of the focused light beams 10 that is reflected specifically includes the focused light beams 10 in the vicinity of the optical axis of the condenser lens 4.

[0057] The reflective shield 9 is attached to the condenser optics 2 at a first side 12 below the condenser lens 4. At a second side 13 opposite the first side 12, the reflective shield 9 comprises an edge 14 facing the focal point 6 of the condenser lens 4. The edge 14 can be close to the focal point 6.

[0058] The optical system 1 further comprises imaging optics 15 formed by an imaging lens matrix 16. In this case, the imaging lens matrix 16 comprises one imaging lens 17. The main extension plane of the imaging optics 15 is substantially parallel to the main extension plane of the condenser optics 2. In the direction x of light propagation, the reflective shield 9 is arranged between the condenser optics 2 and the imaging optics 15. In the vertical direction z, there is an offset between the imaging lens 17 and the condenser lens 4. This means that the centroid of the imaging lens 17 is arranged below the centroid of the condenser lens 4.

[0059] The imaging lens 17 has a focal point 6 that at least approximately matches the focal point 6 of the condenser lens 4. Thus, the condenser optics 2 focuses the incoming light beams 5 onto a focal plane of the imaging optics 15. The focal point 6 is located between the imaging optics 15 and the edge 14 of the reflective shield 9 facing the imaging optics 15. In Figure 1 In the case shown in Fig. 1, the imaging lens 17 is assigned to the condenser lens 4, forming a respective light beam channel 19 within the optical system 1.

[0060] The imaging optics 15 is arranged to project the focused light beams 10 and the reflected light beams 18 in front of the headlamp such that the reflected light beams 18 contribute to an intensity hot spot 34 (not shown) on one side of the cutoff line 33. The side of the cutoff line 33 at which the intensity hot spot 34 is generated faces the road. In other words, in the vertical direction z, the intensity hot spot 34 is below the cutoff line 33. The outgoing light beams 11 can be predominantly parallel.

[0061] The optical system 1 according to Figure 1 The optical system 1 according to Fig. 1 can be understood as one channel of a module 20 of optical systems 1, as shown in the following figures. This means that further channels can be combined. The channels can be arranged next to each other in the lateral direction y or in the vertical direction z. Furthermore, several modules 20 can be combined such that the entire optical system 1 is formed. Accordingly, the figures showing the optical system 1 comprising only one channel can be understood as a schematic representation of one channel of a module 20 of optical systems 1.Figure 1 The features described in the context of the above embodiments can also be applied to embodiments according to the following figures comprising several channels.

[0062] In Figure 2 Another example of an optical system 1 is shown in a perspective view. Figure 2 Embodiments of the above can be considered as a combination of several channels according to Figure 1 so that a module 20 of the optical system 1 is formed.

[0063] In this case, the condenser lens matrix 2 comprises a plurality of condenser lenses 4, namely fifteen condenser lenses 4, which are arranged in three rows and five columns, respectively. The condenser optics 2 comprising the condenser lenses 4 can be formed by one single substrate comprising a transparent material. For example, glass or plastic can be used. For example, the condenser optics 2 is manufactured by injection molding. Figure 2 The number of rows and / or columns shown in the above is arbitrary only. Thus, the condenser lens matrix 3 can comprise a different number of rows and / or columns. The condenser lenses 4 within the condenser lens matrix 3 can focus the incident light beams 5 into different focal points 6 (not shown). However, the focal points can lie on a common plane, also referred to as focal plane.

[0064] In the vertical direction z, a respective reflective shield 9 is arranged below each row of the condenser lens matrix 3. Thus, Figure 2 Embodiments of the above comprise three reflective shields. The reflective shields 9 are arranged parallel to each other.

[0065] The imaging optics 15 is formed by an imaging lens matrix 16, which in this case comprises fifteen imaging lenses 17 arranged in three rows and five columns. Thus, in this example, each of the imaging lenses 17 is assigned to one of the condenser lenses 4. Thus, Figure 2 The module 20 of the above forms fifteen channels 19 of light beams. Specifically, each of the imaging lenses 17 of a particular row of the imaging lens matrix 16 is assigned to a respective condenser lens 4 of the corresponding row of the condenser lens matrix 3. In other words, Figure 2 The module 20 of the above comprises three rows of channels 19 of light beams.

[0066] Each imaging lens 17 projects the focused light beams 10 and the reflected light beams 18 in front of the headlamp, forming an outgoing light beam 11 as shown in Figure 1 This means that each imaging lens 17 contributes to the road illumination by projecting an image. Said images are at least partially superimposed. A sharp cutoff line 33 (not shown) is generated as a superimposed image of the reflective shields 9. Furthermore, since the reflected light beams 18 are also projected by the imaging optics 15, they are not lost but also used for road illumination. Specifically, they contribute to an intensity hotspot 34 (not shown) directly below the cutoff line 33, i.e. on the road-facing side of the cutoff line 33.

[0067] Figure 2 Embodiments of the application further comprise three absorbing shields 21. Each absorbing shield 21 is arranged between the condensing optics 2 and the imaging optics 15 in the light propagation direction x. The absorbing shields 21 are provided to prevent cross-talk between the beam channels 19. In particular, they are provided to prevent cross-talk between the beam channels 19 of different rows of modules 20.

[0068] The absorbing shields 21 can comprise an opaque material. As shown in Figure 2 each absorbing shield 21 is mounted on the respective reflecting shield 9 at a first side 22 and on the imaging optics 15 at a second side 23. The first side 22 of the absorbing shield 21 is mounted on a back side 24 of the reflecting shield 9. The back side 24 of the reflecting shield 9 is opposite to the main surface of the reflecting shield at which the light beams are reflected. The second side 23 of the absorbing shield 21 is mounted on the imaging optics 15 between two corresponding rows of the imaging lens matrix 16. The absorbing shields 21 are generally parallel to each other. A main extension plane of each absorbing shield 21 is tilted with respect to a main extension plane of the reflecting shield 9.

[0069] In Figure 3 another example of an optical system 1 is shown in perspective view. According to Figure 3 embodiments of the application differ from embodiments of the application of Figure 2 in that it shows several kinks 25 in the topmost reflecting shield 9. The kinks are formed by recesses / cuts at the edges 14 facing the imaging optics 15. Each kink 25 is assigned to one of the beam channels 19. Figure 3 The exact number, position and shape of the kinks 25 shown in Figure 3 is merely exemplary and depends on the desired light distribution of the exit light beams 11. In the example of the cuts have a triangular shape, but different shapes are equally possible. Light rays passing through the cuts in the reflecting shield are not reflected. Rather, these light rays are cast by the imaging optics above the cut-off line 33 (not shown). This makes it possible to adjust the light distribution in the individual regions. For example, the right-hand side of the road can be illuminated in such a way that road signs are more easily visible.

[0070] Figure 2 It should be mentioned that Figure 3 the modules 20 shown in may be combined. For example, the modules 20 can be arranged next to each other in the lateral direction y or on top of each other in the vertical direction z.

[0071] In addition, the optical system 1 can comprise further modules 20, wherein the distance of the edge 14 of the reflective shield to the focal plane can vary from one module 20 to another module 20. Furthermore, each module 20 can comprise its own light source (not shown), or the modules can comprise a common light source. By switching on or off the light source of the respective module 20, the light distribution of the outgoing light beam 11 can be adjusted according to the requirements of the road lighting. For example, an optical system 1 comprising such modules 20 can implement both a low beam function and a high beam function.

[0072] Figures 4a to 4c show in cross-section examples of condenser lenses 4 within a condenser lens matrix 3. In Figure 4a, three rows of condenser lenses 4 are shown, wherein each condenser lens 4 is formed as an axially symmetric lens, such that the main surface 8 of the respective condenser lens 4 approximates a spherical, elliptical or parabolic surface.

[0073] In Figure 4b, three rows of condenser lenses 4 are shown, wherein each condenser lens 4 is formed as a segment of an axially symmetric lens, such that the main surface 8 of the respective condenser lens 4 approximates a slice from a spherical, elliptical or parabolic surface. In particular, the condenser lenses 4 are formed by half of an axially symmetric lens. Such condenser lenses 4 have also been shown in Figures 1 to 3 .

[0074] In Figure 4c, three rows of condenser lenses 4 are shown, wherein the main surface 8 of the respective condenser lens 4 is formed as a free-form surface.

[0075] Figure 4d shows an optical system with another example of a condenser lens matrix. In this example, the condenser lenses 4 of the condenser lens matrix 3 are formed as stigmatic lenses, in particular as segments of cylindrical lenses. This means that the condenser lens matrix 3 is formed by multiple rows of condenser lenses 4, wherein at least one row forms segments of cylindrical lenses. In this case, the imaging lenses 17 of a respective row of the imaging lens matrix 16 are assigned to the same condenser lens 4.

[0076] It should be mentioned that the condenser optics 2 can comprise different kinds of condenser lenses 4 (as shown in Figures 4a to 4d) in the same condenser lens matrix 3. It is also possible that the optical system 1 comprises several modules 20, wherein the condenser lenses 4 of different modules are shaped differently. For example, as shown in Figure 4d, a module 20 comprising condenser lenses 4 formed as segments of cylindrical lenses is suitable for providing a wide field of illumination.

[0077] Fig. 5a shows an example of the imaging optics 15 formed by the imaging lens matrix 16 in a perspective view. Like the condenser lens matrix 3, the imaging lens matrix 16 can be formed by one single substrate comprising a transparent material. For example, glass or plastic can be used. The imaging optics 15 is manufactured, for example, by injection molding. The number of rows and / or columns shown in Fig. 5a is arbitrary only. In this way, the imaging lens matrix 16 can comprise a different number of rows and / or columns, i.e. the number of imaging lenses 17 is arbitrary.

[0078] Fig. 5b shows another example of the imaging optics 15 in a perspective view. In this example, the imaging lenses 17 of the imaging lens matrix 16 are separated by a grid 26 of additional absorbing shields 27. The grid 26 of additional absorbing shields 27 is provided to prevent cross-talk between the exit light beams 11 (not shown). This means that there is an additional absorbing shield 27 between two adjacent imaging lenses 17 within the imaging lens matrix 16. The absorbing shields comprise an opaque material, for example a plastic material.

[0079] For example, the grid 26 of additional absorbing shields 27 is manufactured by injection molding to form a holder. Then, the individual imaging lenses 16 are inserted into the grid 26 in order to form the imaging lens matrix 16. In this case, the imaging lenses 17 and the grid 26 of additional absorbing shields 27 are assembled separate parts.

[0080] Alternatively, the imaging lens matrix 16 is formed by a single transparent substrate which is shaped into the desired shape such that a plurality of imaging lenses 17 is formed. Then, the grid 26 is generated by over-molding the substrate with an opaque material. In this case, the imaging lens matrix 16 and the grid 26 form part of the optical system 1.

[0081] In Fig. 6a, the optical system 1 comprising a collimating optics 28 is shown in a cross-section. The collimating optics 28 provides the collimated incident light beams 5. The collimating optics 28 comprises a light source 29 and a collimating lens 30. The collimating lens 30 is arranged between the light source 29 and the condenser optics 2 comprising the condenser lens matrix 3. The condenser lens matrix 3 is arranged between the collimating lens 30 and the imaging optics 15.

[0082] As shown in Fig. 6a, the light source can emit light in a wide range of directions. In other words, the emitted light beams 31 are highly divergent. The collimating lens 30 redirects the emitted light beams 31 such that the collimated incident light beams 5 are generated. The collimating lens 30 can comprise a plastic material. For example, the collimating lens 30 can be formed by injection molding. In the example of Fig. 6a, the collimating lens 30 forms a separate part of the optical system 1.

[0083] However, the collimating lens 30 can also be integrated in the condenser optics 2, as shown in Fig. 6b. The collimating lens 30 is arranged on the back side 7 of the condenser optics 2 facing the light source 29. The condenser lens matrix 3 is arranged on the main surface 8 of the condenser optics 2 facing the imaging optics 15. This means that the collimating lens 30 and the condenser lens matrix 3 are formed by a part of the optical system 1. In particular, the collimating lens 30 and the condenser lens matrix 3 comprise the same material, e.g. a plastic material. The collimating lens 30 and the condenser lens matrix 3 can both be formed in the same step of the manufacturing process.

[0084] The collimating lens 30 can redirect the emitted light beam 31 by means of refraction and / or by means of total internal reflection (TIR). TIR occurs when light in one medium reaches the boundary with another medium at a sufficiently glancing angle, provided that the second (“external”) medium is transparent to the waves and allows them to travel faster than in the first (“internal”) medium. The angle of incidence at the boundary must exceed a certain value, which is called the critical angle of total reflection. Then, the light no longer enters the second medium (in this case the ambient air), but is almost completely reflected in the first medium (the collimating lens). Thus, in order for TIR to occur, the refractive index of the collimating lens can be larger than the refractive index of the surrounding air. The inclination of at least some surfaces of the collimating lens can be such that the angle of incidence exceeds the critical angle in terms of light propagation. In the example of Fig. 6b, the central part of the collimating lens 30 redirects the emitted light beam 31 by means of beam refraction, while the outer part of the collimating lens 30 redirects the emitted light beam 31 by means of TIR.

[0085] Fig. 7a shows a map of the light intensity 32 of the exit light beam 11 of the optical system 1 of Fig. 4, according to Figure 2 or Fig. 6a. The light intensity 32 is determined from simulation results and is shown on a rectangular detector screen at a certain distance from the optical system 1. The light intensity 32 is shown as a function of the position on the screen in the lateral direction y and the vertical direction z. However, the scaling of the y-axis and the z-axis is quite arbitrary.

[0086] The light distribution is symmetrical with respect to the lateral position at y = 0. Furthermore, it can be seen that there is a sharp bright / dark boundary, also called a cutoff line 33, at the vertical position at z = 0, which is marked by a dashed line. Below the cutoff line 33, i.e. for values z < 0, the light intensity has a maximum value. For values z > 0, the light intensity 32 decreases rapidly. The maximum value of the light intensity 32 is also called a hot spot 34.

[0087] In Fig. 7b, a graph is shown representing the light intensity 32 at the lateral position y = 0 as a function of the vertical position z according to Fig. 7a. The linear scaling of the z-axis is rather arbitrary, as is the linear scaling of the intensity axis (I-axis). It can be seen that the intensity rises to a maximum, i.e. a hot spot 34 at a vertical position z = 0. For values z > 0, the light intensity 32 decreases rapidly, resulting in a cutoff line. The distribution of the light intensity 32 can be designed according to the requested illumination of the road.

[0088] Fig. 7c shows another mapping of the light intensity 32 of the exit beam 11 of the optical system 1 according to Figure 3 Fig. 7a. As in Fig. 7a, the light intensity 32 is determined from simulation results and is shown on a rectangular detector screen at a distance from the optical system 1. In the example of Fig. 7c, the light distribution is not axis-symmetric. Rather, on the right-hand side, the beam 11 is projected above the cutoff line 33. Thus, there is a region 35 above the cutoff line 33 in which the intensity values do not vanish. As mentioned above, this light distribution can be caused by one or more kinks in at least one of the reflective shields 9 of the optical system 1 (see Fig. 6). For example, such a light distribution makes it easier to see road signs on the right-hand side of the road. Figure 3 ). For example, such a light distribution makes it easier to see road signs on the right-hand side of the road.

[0089] For the purpose of familiarizing the reader with the novel aspects of the present concept, embodiments of the optical system disclosed herein have been discussed. Although a preferred embodiment has been shown and described, one skilled in the art can make many changes, modifications, equivalents, and substitutions for the disclosed concept without necessarily departing from the scope of the claims.

[0090] It is to be understood that the present disclosure is not limited to the disclosed embodiments and what is specifically described hereinabove and hereinbelow. Rather, features from the separate dependent claims or from the description herein can be combined as appropriate, and the described embodiments are illustrative. Also, the scope of the present disclosure includes what is claimed as well as modifications obvious to those skilled in the art that are not specifically enumerated in the claims.

[0091] The use of the term “including” in a claim or the specification is not a limitation on the scope of what is covered. Rather, the term means “including, but not limited to.” The term “comprising” is intended to mean that the composition or process include the recited elements, but not excluding others. “Consisting essentially of’ when used in the claims or the specification means including the recited elements plus other elements that do not materially affect the basic and novel characteristic(s) of the composition or process. Any reference to “an implementation” or “one implementation” means that a particular element can implement a currently preferred embodiment. Embodiments of the present disclosure covering functional, constructive, positional and / or anatomical equivalents are within the scope of the claims.

[0092] This patent application claims priority to German patent application 102020131999.1, the disclosure of which is incorporated herein by reference.

[0093] Reference Signs

[0094] 1 optical system

[0095] 2 condenser optics

[0096] 3 condenser lens matrix

[0097] 4 condenser lens

[0098] 5 incident light beam

[0099] 6 focal point

[0100] 7 back side of the condensing optics

[0101] 8 main surface of the condensing optics

[0102] 9 reflective shield

[0103] 10 focused light beam

[0104] 11 outgoing light beam

[0105] 12 first side of the reflective shield

[0106] 13 second side of the reflective shield

[0107] 14 edge of the reflective shield

[0108] 15 imaging optics

[0109] 16 imaging lens matrix

[0110] 17 imaging lens

[0111] 18 reflected light beam

[0112] 19 passage of the light beam

[0113] 20 module

[0114] 21 absorbing shield

[0115] 22 first side of the absorbing shield

[0116] 23 second side of the absorbing shield

[0117] 24 back side of the reflective shield

[0118] 25 kink

[0119] 26 grid of additional absorbing shields

[0120] 27 additional absorbing shield

[0121] 28 collimating optics

[0122] 29 light source

[0123] 30 collimating lens

[0124] 31 emitted light beam

[0125] 32 light intensity

[0126] 33 cut-off line

[0127] 34 hot spot

[0128] 35 region

[0129] x direction of x-ray propagation

[0130] y transverse direction

[0131] z vertical direction

Claims

1. An optical system (1) for a headlight of a motor vehicle, comprising: - A focusing optical device (2) is formed by a focusing lens matrix (3) and is configured to focus the incident beam (5). - Multiple reflective shields (9) are configured to reflect at least a subset of the focused beam (10) and generate a cutoff line (33) for the outgoing beam (11), and - Imaging optics (15), formed by an imaging lens matrix (16) and configured to project the focused beam (10) and the reflected beam (18) in front of the headlight, such that the reflected beam (18) contributes to an intensity hotspot (34) on one side of the cutoff line (33), wherein - At least one of the plurality of reflective shields (9) includes a kink (25) at the edge (14) facing the imaging optics (15). The reflective shield (9) is arranged between the focusing optics (2) and the imaging optics (15), the main extension plane of the focusing optics (2) is parallel to the main extension plane of the imaging optics (15), and the main extension plane of the reflective shield (9) is perpendicular to the main extension plane of the imaging optics (15), such that the reflected beam (18) that would otherwise be projected by the imaging optics (15) above the horizontal cutoff line contributes in the vertical direction to the intensity hot spot (34) below the cutoff line (33).

2. The optical system (1) according to claim 1, wherein the condenser lens matrix (3) comprises a plurality of condenser lenses (4), and wherein the imaging lens matrix (16) comprises a plurality of imaging lenses (17), each of the imaging lenses (17) being assigned to one of the condenser lenses (4) to form a channel (19) for a corresponding beam within the optical system (1).

3. The optical system (1) according to claim 2, wherein in the vertical direction (z), there is an offset between the imaging lens (17) and the corresponding condenser lens (4) to which the imaging lens (17) is assigned, wherein the vertical direction (z) extends perpendicularly to the main extension plane of the at least one reflective shield (9).

4. The optical system (1) according to any one of claims 2 to 3 further includes at least one absorption shield (21) disposed between the focusing optics (2) and the imaging optics (15), the at least one absorption shield (21) being configured to prevent crosstalk between the channels (19) of the light beam.

5. The optical system (1) according to any one of claims 2 to 3, wherein the focal plane of the focusing optics (2) is at least approximately matched with the focal plane of the imaging optics (15), such that the focusing optics (2) focuses the incident light beam (5) onto the focal plane of the imaging optics (15).

6. The optical system (1) according to any one of claims 2 to 3, wherein the condenser lens matrix (3) comprises a plurality of condenser lenses (4), and wherein at least one condenser lens (4) of the condenser lens matrix (3) is formed as an axisymmetric lens such that the main surface (8) of the corresponding condenser lens (4) is approximately spherical, elliptical or parabolic.

7. The optical system (1) according to any one of claims 2 to 3, wherein the condenser lens matrix (3) comprises a plurality of condenser lenses (4), and wherein at least one condenser lens (4) of the condenser lens matrix (3) is formed as a segment of an axisymmetric lens such that the main surface (8) of the corresponding condenser lens (4) approximates a slice from a spherical, elliptical or parabolic surface.

8. The optical system (1) according to any one of claims 2 to 3, wherein the condenser lens matrix (3) comprises a plurality of condenser lenses (4), and wherein at least one condenser lens (4) of the condenser lens matrix (3) is formed as an astigmatic lens, or such that the main surface (8) of the corresponding condenser lens (4) is formed as a free-form surface.

9. The optical system (1) according to any one of claims 2 to 3, wherein the focusing optics (2) is configured such that its focal plane is between the imaging optics (15) and the edge (14) of the at least one reflective shield (9) facing the imaging optics (15), but closer to the edge (14).

10. The optical system (1) according to any one of claims 2 to 3 further includes a collimating optics (28) for providing a collimated incident beam (5), the collimating optics (28) including a light source (29) and a collimating lens (30), wherein the collimating lens (30) is disposed between the light source (29) and the condenser lens matrix (3), and the condenser lens matrix (3) is disposed between the collimating lens (30) and the imaging lens matrix (16).

11. The optical system (1) according to claim 10, wherein the collimating lens (30) is integrated in the condensing optics (2) such that the collimating lens (30) is arranged on the rear side (7) of the condensing optics (2) facing the light source (29), and the condensing lens matrix (3) is arranged on the main surface (8) of the condensing optics (2) facing the imaging optics (15).

12. The optical system (1) according to any one of claims 2 to 3, wherein the imaging lens (17) of the imaging lens matrix (16) is separated by a grid (26) of an additional absorption shield (27) configured to prevent crosstalk between the outgoing beams (11).

13. The optical system (1) according to claim 8, wherein at least one condenser lens (4) of the condenser lens matrix (3) is formed as a cylindrical lens.

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