Lighting device for a vehicle

Abstract

The invention relates to a lighting device (1) for a vehicle, wherein the lighting device (1) comprises a light source (10) configured to generate light and emit it in a predetermined direction (VR). The lighting device (1) also comprises an intermediate light filter (20) configured to couple the light incident with a deflection direction (AR) on a first side (21) of the intermediate light filter (20), to guide it to a second side (22) of the intermediate light filter (20), and to emit it from the second side (22) in a light output direction (OA).The intermediate light disk (20) comprises a plurality of light blocks (23) arranged one behind the other in the direction of deflection (AR), each of the plurality of light blocks (23) comprising a light coupling section (231) arranged on the first side (21) and a light coupling section (234) arranged on the second side (22), the light coupling section (231) having a light coupling surface (232) and a reflection surface (233) and the light coupling section (234) having a light coupling surface (235), the light coupling surfaces (232) of the plurality of light blocks (23) forming a continuous projection surface (P) from the perspective of the light incident in the direction of deflection (AR).

Description

[0001] The invention relates to a lighting device for a vehicle.

[0002] Current lighting devices for vehicles must meet a variety of requirements. These include the number of lighting functions to be achieved, normative and / or legal regulations, and the limitation of the available installation space. In addition, there is an increasing demand for design and aesthetic requirements. Among other things, the latest design trends show recurring patterns that are implemented by the lighting device, such as stripes in the prominent headlight and taillight functions, which are also referred to as signatures. These include, for example, the daytime running light or the brake light.

[0003] Common solutions for characteristic or repeating structures include repeating identical or varying optical elements. For each luminous surface that forms part of the overall structure, at least one light source, such as an LED, is used. In other words, a light source is equipped with primary optics, such as a reflector, which projects the light onto a light-conducting element, where it is then coupled. Gaps between the individual elements are masked, e.g., with a diaphragm. Another common option is to illuminate the entire surface with a large reflector and mask the non-luminous areas.

[0004] The associated disadvantages include, among other things, the fact that, for example, with numerous delicate optics, the number of LEDs and thus the circuit board size are constantly increasing. Given the unfavorable height-to-width ratio of the illuminated surfaces that is common today, the complexity of the coupling optics also increases and efficiency deteriorates. However, if the approach of illuminating the entire surface and masking (shading) certain areas is used, a large proportion of the light is lost unused. For light-intensive functions such as daytime running lights, this is associated with high costs and energy consumption, and is also only feasible to a limited extent due to system limitations (e.g., maximum power).

[0005] The invention is based on the object of providing a lighting device for a vehicle which at least partially overcomes the aforementioned disadvantages of the prior art.

[0006] The objects are achieved entirely or at least partially by a lighting device for a vehicle having the features of the independent claim. Further preferred embodiments of the invention emerge from the remaining features mentioned in the subclaims.

[0007] According to the invention, a lighting device for a vehicle is provided, wherein the lighting device comprises a light source configured to generate light and emit it in a predetermined direction. Furthermore, the lighting device comprises an intermediate light plate configured to couple the light incident on a first side of the intermediate light plate with a deflection direction, to guide it to a second side of the intermediate light plate, and to emit it via the second side in a light output direction.The intermediate light disc comprises a plurality of light modules arranged one behind the other in the deflection direction, wherein each of the plurality of light modules comprises a light coupling section arranged on the first side and a light coupling section arranged on the second side, wherein the light coupling section has a light coupling surface and a reflection surface and the light coupling section has a light coupling surface, wherein the light coupling surfaces of the plurality of light modules form a continuous projection surface from the perspective of the light incident in the deflection direction.

[0008] When considering the path of light, reference is made within the scope of the present invention to ray optics and the ray model that is used for observation and light guidance. The ray model is the basis of geometric optics; using this model, the propagation of light and its modification by imaging elements (refracting and reflecting elements) can be described in a simple geometric way. The ray model describes the propagation of light by mathematical lines of one-dimensional extension, the so-called light rays. A large number of light rays that intersect at a common point are referred to as a light beam. This light beam has, among other things, geometric shapes such as cones or triangles.

[0009] When explanations are given for one light module, these explanations refer to each of the plurality of light modules, unless explicitly stated or described otherwise.

[0010] In other words, the intermediate light disc has an illumination side arranged on the first side of the intermediate light disc and an emission side arranged on the second side of the intermediate light disc. In other words, at least a portion of the emission side forms a luminous surface of the lighting device.

[0011] The light emitted by the light source therefore strikes the intermediate light disc on the first side in the deflection direction and is coupled into the intermediate light disc there under a refraction that depends on the material. The law of refraction describes the deflection of a light beam at the transition between two media. The angle of refraction depends on the refractive indices of the two media and the angle of incidence of the light beam. Within the intermediate light disc, the coupled-in light is guided by internal reflection to the second side, where it is coupled out under further refraction and emitted in the light output direction. The light output direction is also referred to as the main emission direction, light output direction or optical axis of the lighting device. It is preferably predetermined, in particular to meet the requirements of the lighting device in practical application.

[0012] The plurality of light modules arranged one behind the other in the deflection direction preferably have the same dimensions and are thus structurally identical. Accordingly, they comprise a repeating structure on the first and second sides.

[0013] Each of the plurality of light modules comprises a light coupling section arranged on the first side of the intermediate light plate. Accordingly, the light coupling section is arranged on the first side of the intermediate light plate, so that the light strikes the light coupling section in the deflection direction, and the portion of the light striking there is coupled in. The coupling occurs at least through the light coupling surface for coupling the light, onto which the light, or at least a portion of the light, strikes, where it enters the light module and thus also the intermediate light plate under refraction.Furthermore, the light coupling section has a reflection surface for reflecting coupled-in light, which is preferably arranged opposite and facing the light coupling surface, wherein the light coupled in via the light coupling surface subsequently strikes the reflection surface, at which it is reflected and guided within the light module.

[0014] Preferably, the light coupling section is prism-shaped.

[0015] The light source is preferably arranged on a circuit board.

[0016] Each of the plurality of light modules further comprises a light-outcoupling section arranged on the second side of the intermediate light pane, wherein the light-outcoupling section has a light-outcoupling surface for coupling out the light. In other words, at least a portion of the light-outcoupling sections forms at least a portion of the luminous surface of the lighting device.

[0017] According to the invention, the light coupling surfaces of the plurality of light modules form a coherent (continuous) projection surface from the perspective of the light incident in the deflection direction. In other words, the light coupling surfaces form a substantially closed projection surface. In other words, the projection surface is an optical surface or plane that, from the perspective of the incident light, is composed of the individual light coupling surfaces of the light modules. The projection surface represents an optically coherent surface because the light coupling surfaces of the plurality of light modules are optically connected to one another, at least when viewed from the propagation direction.In geometry or optics, a projection surface or imaging surface is the surface, also called the projection plane, onto which an original image is projected, reflected, or projected by rays. In other words, the majority of light modules arranged one behind the other in the direction of deflection are offset from one another in the direction of an axis or straight line running perpendicular to the direction of deflection. It should be noted that this offset can be achieved structurally, or be based solely on viewing in the direction of deflection and in the direction of the axis running perpendicular to the direction of deflection, or represent a combination of both factors. In particular, with identically constructed, repeating light modules, this offset is ensured by the direction of deflection.In other words, the light modules arranged one behind the other in the deflection direction overlap based on an observation direction that corresponds to the deflection direction, and the offset of the light modules arranged one behind the other occurs only in one direction with respect to the axis running perpendicular to the deflection direction, with the offset of light modules arranged further downstream in the deflection direction steadily increasing with respect to the axis running perpendicular to the deflection direction. Accordingly, the projection surface is formed by areas of the light coupling sections arranged in the deflection direction and remaining free, these areas representing the light coupling surfaces.

[0018] According to one embodiment, the predetermined direction in which the light is emitted from the light source coincides with the deflection direction. Accordingly, the emitted light is not deflected before striking the first side of the intermediate light disc.

[0019] In a preferred embodiment of the invention, the lighting device is a headlight of the vehicle, which provides, in particular, a low beam, a high beam, approach lighting and / or projections onto a roadway, and / or a tail light or a part of these components. At least the headlight comprises a daytime running light, wherein the intermediate light lens achieves the lighting function of the daytime running light. In the case of a headlight or a tail light, the lighting device further comprises an outer light lens arranged on the second side of the intermediate light lens, and a rear cover arranged on the first side. Headlights preferably emit light in their direction of travel. Accordingly, in this case, the direction of light propagation corresponds to the direction of travel.In the case of the tail light, the direction of light propagation corresponds to the opposite direction of travel.

[0020] In a further embodiment of the invention, the lighting device is an interior lighting, whereby the direction of light propagation depends on the specific application.

[0021] In a further embodiment of the invention, the lighting device is a light for the vehicle's radiator grille, whereby the direction of light propagation depends on the specific application. Lighting of the radiator grille is also frequently provided, particularly along the grille's ribs.

[0022] In a further preferred embodiment of the invention, it is provided that at least some of the plurality of light modules are formed by respective projections on the first side of the intermediate light disc. Accordingly, these light modules are given an exposed position relative to a base area of ​​the intermediate light disc. One projection forms a light module. The projections of the respective light modules preferably have identical dimensions to one another, so that they have the same dimensions and height relative to the base area of ​​the intermediate light disc on the first side. The projections therefore comprise the respective light coupling sections, and the respective surfaces of the projections of the light modules facing the light traveling in the deflection direction comprise the light coupling surfaces.In other words, the light coupling surface of each light module is formed by the surface of the projection onto which the light impinges in the deflection direction before being coupled into the light coupling sections. Furthermore, the projections are arranged relative to the deflection direction such that each of these projections has a minimum surface onto which the light impinges. This is ensured by the relative offset in the deflection direction along the axis of the light modules running perpendicular to the deflection direction. Accordingly, a light module arranged further upstream in the deflection direction can partially obscure a neighboring light module further upstream in the deflection direction, while the minimum surface representing the light coupling surface remains exposed.A surface of the projections of the light modules facing away from the light traveling in the deflection direction comprises the reflection surface onto which the light impinges after being coupled into the light coupling sections within these. This creates an optically coherent projection surface in a space-saving manner. The projections effectively provide light coupling sections with the light coupling surface and the reflection surface, wherein the projections represent an efficient way of utilizing a large portion of the light with respect to the one provided light source. Preferably, each of the plurality of light modules is formed by such a corresponding projection.

[0023] The projections of the light modules preferably form a sawtooth pattern. Each of the projections therefore has a triangular cross-section. Preferably, the side of the projection corresponding to the surface of the projections of the light modules facing the light traveling in the deflection direction extends at an angle between 45° and 90°, preferably 90°, from the base area of ​​the intermediate light disc. This advantageously utilizes the base area of ​​the intermediate light disc, since these projections increase the surface area, which promotes the coupling of light into the projections, and the projections in the form of a sawtooth pattern provide a suitable light coupling surface and reflection surface.

[0024] Preferably, the intermediate lens is formed as a single piece. Accordingly, the light modules are also an integral part of the intermediate lens. This significantly simplifies the manufacturing process for the intermediate lens, including the features according to the invention.

[0025] According to a further preferred embodiment of the invention, the majority of the light modules are spaced apart from one another. Accordingly, each light module comprises separate contours from the other light modules, so that each light module provides a suitable light coupling surface and reflection surface and furthermore represents a light guide that directs the coupled light to the desired and predetermined location through internal reflection at the surfaces formed by its contours, where the light is then output. At the same time, material savings can be achieved.

[0026] Preferably, the light modules are configured to create a signature and / or a pattern on the second side. This provides a lighting device equipped with only one light source, thereby reducing energy and material consumption and also reducing space requirements due to the reduced number of light sources and circuit board size, without compromising the lighting function.

[0027] According to a further preferred embodiment of the invention, it is provided that at least a part of the light extraction sections of the majority of the light building blocks comprises respective protrusions, preferably stepped protrusions, on the second side of the intermediate light disc. Thereby, these light building blocks form an optical structure on the second side, which is particularly suitable for generating the signature. At the stepped protrusions or their outer surfaces, the previously coupled-in and guided light within the light building block is extracted and radiated, such that the stepped protrusions form part of the illuminated area of the lighting device. Depending on their arrangement, they accordingly generate a pattern that achieves the signature. Preferably, each of the light extraction sections of the majority of the light building blocks comprises this protrusion.

[0028] Particularly preferably, regions of the intermediate light disc on the second side between adjacent projections of the light-coupling sections are concealed by a screen. In other words, regions through which light propagating in the intermediate light disc can be coupled out and emitted are masked, so that no light leaves the intermediate light disc there. Accordingly, only the projections of the light-coupling sections constitute the luminous surface of the lighting device, and the pattern is more strongly emphasized.

[0029] According to a further embodiment of the invention, the lighting device comprises deflecting optics arranged in the predetermined direction, which are designed to deflect the light in the deflection direction. The deflection optics preferably comprise a reflector. Accordingly, the light emitted from the light source in the predetermined direction strikes the deflection optics and is deflected there. The deflection preferably occurs in the deflection direction. This makes it possible to collect a wide light cone generated by the light source and deflect it with a desired width in the deflection direction. The width of the light cone preferably corresponds to a width of the projection surface in the deflection direction. This allows the light to be used particularly efficiently, and the unused portion of the light, which cannot be completely avoided due to divergence, is reduced.Collimation of the light is also possible using the deflection optics, so that the divergence can be reduced.

[0030] Preferably, an angle, also referred to as deflection, between the light output direction and the deflection direction is between 25° and 70°, preferably 30° and 65°, and particularly preferably between 35° and 60°. This angle is referred to below as deflection. The inventor was able to deduce through calculations that various optical requirements are met at these angles. Various processes influence the propagation direction of the emitted light upon coupling into the intermediate light disc. First, the light is refracted upon entering from the surrounding medium, which is usually air with its characteristic refractive index, via the light coupling surface of the light coupling section into the intermediate light disc, which is made of PMMA, for example.Care must be taken to ensure that the angle between the deflection direction and the light coupling surface does not become too shallow, as this would result in the phenomenon of Fresnel reflection, which manifests itself in reduced transmission and thus reduces efficiency. Satisfactory internal reflection of the incoming light at the reflection surface of the light module must also be taken into account. The inventor has also taken into account a certain degree of divergence of non-ideally collimated incoming light. Further light refraction occurs when the light guided within the light module exits via its light exit surface into the surrounding medium, usually air again. Fresnel reflection must also be taken into account here to ensure sufficient transmission and the light can leave the light module and thus the intermediate light disc again.For this purpose, corresponding critical angles are to be defined upon the transition between the optical media, which naturally depend on the geometric conditions and the orientation of the intermediate light disk and are to be taken into account during implementation. However, a favorable order of magnitude is ensured by the angle ranges mentioned above. In addition, the intermediate light disk is usually constructed in such a way that it achieves the corresponding light propagation direction, for example along the driving direction in the case of a headlight. For these specifications, the angles mentioned are particularly efficient in terms of light utilization.

[0031] Preferably, an angle of inclination, also referred to as demolding, between the light coupling surface and the light output direction is between 3° and 20°, preferably between 7° and 16°, and particularly preferably between 10° and 13°. This angle of inclination of the light coupling surface can also be referred to as demolding E of the light modules. This controls the influence of the aforementioned factors on the light guidance. In conjunction with the light source and, if applicable, the deflection optics, the installation space can be reduced in the depth direction while simultaneously increasing efficiency.

[0032] Furthermore, in the case of the front and rear vehicle headlights described above, these have a certain inclination. Headlights in particular have an inclination. In the context of the present invention, this is referred to as sweep and quantifies the angle between the headlight and the vehicle's transverse axis in the top view and with the headlight mounted. Preferably, the intermediate lens corresponds to the arrangement of the headlight as a whole, so that it has the same sweep. Preferably, the sweep is greater than 0° and less than 50°. By combining this sweep with the described deflection angles and inclination angles as well as the demolding, the inventor was able to significantly reduce the effects of Fresnel reflection.

[0033] According to a further embodiment of the invention, the light modules are designed to achieve total reflection of coupled light at the reflection surface. As a result, the coupled light does not leave the light module at the reflection surface, but is completely reflected at the reflection surface and is available for further transmission within the light module.

[0034] Further preferred embodiments of the invention result from the remaining features mentioned in the subclaims.

[0035] The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless stated otherwise in the individual case.

[0036] The invention is explained below in exemplary embodiments with reference to the accompanying drawings. They show: Fig. 1 a lighting device according to a first embodiment of the invention, Fig. 2 a lighting device according to a second embodiment of the invention, Fig. 3 a lighting device according to a third embodiment of the invention, Fig. 4 a schematic representation of a light module of a lighting device of the Fig. 1-3, Fig. 5a is a schematic representation of light paths in a lighting device according to an embodiment of the invention, Fig. 5b a detailed view of a light module of the lighting device from Fig. 5a, Fig. 5c Results of the calculation of the minimum deflection, Fig. 5d Results of the calculation of the maximum deflection.

[0037] Fig. 1 shows a lighting device 1 according to a first embodiment of the invention. The lighting device 1 comprises an LED 10 as a light source 10, which is arranged on a circuit board 11 and is designed to generate light and emit it in a predetermined direction VR. The lighting device 1 also comprises an intermediate light plate 20, which is designed to couple in the light incident on a first side 21 of the intermediate light plate 20 with a deflection direction AR. Furthermore, the intermediate light plate 20 has a second side 22, to which the light is guided within the intermediate light plate 20. The light is coupled out via the second side 22 and emitted in a light output direction OA, so that a luminous surface is formed on the intermediate light plate 20.The intermediate light pane 20 comprises a plurality of light modules 23 arranged one behind the other in the deflection direction, which, according to the present embodiment, are structurally identical but can also have different geometric shapes. Each of the plurality of light modules 23 comprises, in the present case, a prism-shaped light coupling section 231 arranged on the first side 21 and a light coupling section 234 arranged on the second side 22, which, according to the present embodiment, represents a partial region of an outer surface of the intermediate light pane 20. The light coupling section 231 has a light coupling surface 232 and a reflection surface 233. The light coupling section 234 has a light coupling surface 235.

[0038] Furthermore, the lighting device 1 comprises an outer lens 50 arranged on the second side 22 of the intermediate lens 20, as well as a rear cover 30 arranged on the first side 21. This lighting device 1 is preferably a headlight or part of a headlight. This preferably emits light in the direction of travel of the vehicle on which it is arranged. Accordingly, in this case, the light propagation direction OA corresponds to the direction of travel.

[0039] The lighting device 1 comprises a deflection optic 40 arranged in the predetermined direction VR. In the present case, this is a reflector 40. Accordingly, the light emitted from the light source 10 in the predetermined direction VR strikes the deflection optic 40 and is deflected there. The deflection occurs in the deflection direction AR. This makes it possible to collect a wide light cone generated by the light source 10 and deflect it with a desired width in the deflection direction AR. The width of the light cone preferably corresponds to a width of a projection surface P in the deflection direction AR.

[0040] In addition, the light coupling surfaces 232 of the plurality of light modules 23 form the optically coherent, closed projection surface P from the perspective of the light incident in the deflection direction AR. Fig. 1 also shows the offset (or staggered) arrangement of the light modules 23 with respect to the deflection direction AR, which in this case is not achieved by the geometric shape and arrangement of the light modules 23 on the intermediate light panel 23, but could also be realized in this way. In this case, the offset results from the relative arrangement in the deflection direction AR. The light modules 23 have this offset along an axis running transversely to the deflection direction. Light modules 23 arranged closer to the reflector 40 or upstream of the deflection direction AR thus protrude less into the light cone than light modules arranged further away or downstream of the deflection direction AR. Accordingly, light modules 23 arranged closer to the reflector 40 or upstream of the deflection direction AR overlap adjacent light modules 23 arranged further away or downstream of the deflection direction AR.Due to this arrangement, each light module 23 comprises a partial surface which in the present case corresponds to the light coupling surface 232, which is arranged at a different depth than the partial surface of another light module 23 with respect to the deflection direction AR, but which forms a continuous surface onto which the light strikes with respect to a projection which can also be understood as a plan view in the direction of the deflection direction AR.

[0041] Fig. Figure 2 shows a lighting device 1 according to a second embodiment of the invention. Regarding identical features, reference is made to the description of Fig. 1, so that only different features of the second version will be explained in more detail below.

[0042] The lighting device 1 in this case comprises light modules 23 designed to generate a signature on the second side 22. The light-coupling sections 234 comprise stepped projections. In other words, the light modules form elevations relative to an outer surface on the second side 22 of the intermediate light disk 20. These elevations form part of the luminous surface of the intermediate light disk 20, since the light coupled in via the light-coupling section 231 is guided within the light modules 23 to the light-coupling sections 234 and emitted there via their light-coupling surfaces 235, which accordingly form a luminous structure. Regions of the intermediate light disk 20 on the second side 22 between adjacent projections of the light-coupling sections 234 are concealed by a cover 30.In other words, areas through which light propagating in the intermediate light plate 20 can be decoupled and emitted are masked, so that no light leaves the intermediate light plate 20 there. Accordingly, only the projections of the light-coupling sections 234 represent the luminous surface of the lighting device 1, and the pattern is more prominent. This provides a lighting device 1 that is equipped with only one light source 10, thereby reducing energy and material consumption and also reducing the space requirement due to the reduced number of light sources 10 and the size of a circuit board 11, without compromising the lighting function.

[0043] The light coupling sections 23 differ from those of Fig. 1, that they are in accordance with Fig. 2 comprise a triangular projection on the first side 21 of the intermediate lens 23.

[0044] Fig. Figure 3 shows a further lighting device 1 according to a third embodiment of the invention. Regarding identical features, reference is made to the description of Fig. 1, so that only different features of the second version will be explained in more detail below.

[0045] The intermediate light disc 20 comprises only a narrow base body, on the first side 21 of which the light coupling sections 231 extend in the form of prism-shaped projections, and on the second side 22 of which the light coupling sections 234 extend in the form of stepped projections. The intermediate light disc 20 is manufactured in one piece with the light modules 23. Its base body thus forms a structural element that essentially serves to arrange the light modules 23.

[0046] Fig. 4 shows a schematic representation of the light module 23 of the lighting device as shown in the Fig. 1 and Fig. Shown in FIG. 3. The light coupling section 231 is shown with its light coupling surface 232 through which the light traveling along the deflection direction AR enters, then strikes the reflection surface 233 and is reflected there. By internally guiding the light, the light reaches the light extraction section 234, where it is extracted through the light extraction surface 235 and radiated in the direction of the light propagation direction OA.

[0047] Based on the Fig. 5a and Fig. 5b, the light propagation will now be explained in more detail. Fig. FIG. 5a shows a schematic representation of light paths in an illumination device 1 according to an embodiment of the invention. A middle light disk 20 with a first side 21 and a second side 22 is shown. The illustration is simplified for the sake of clarity, such that the structure of the light building blocks 23 in Fig. 5a is not shown. Light from a light source 10 strikes the intermediate lens 20 with the deflection direction AR on the first side 21, is coupled into the intermediate lens 20, guided within it, and radiated on the second side 22 in the light propagation direction OA. Furthermore, an arrowing α of the intermediate lens 20 is shown, which relates to use in the headlight of a vehicle and is defined by the angle between an axis running transversely to the direction of travel and the intermediate lens.

[0048] Fig. 5b now shows a detailed view of a light module 23 of the lighting device 1 from Fig. 5a.

[0049] A portion of the intermediate light disc 20 and its base body is depicted with the first side 21 and the second side 22. The first side 21 depicts a light module 23 with a dirt-shaped cross-sectional area, which comprises a light coupling section 231 with a light coupling surface 232 and a reflection surface 233. The second side 22 depicts the light extraction section 234 with a light extraction surface 235. The emitted light strikes the light coupling surface 232 in the deflection direction AR, is refracted there, then strikes the reflection surface 233, where it is reflected, and finally exits the light module 23 and the intermediate light disc 20 via the light extraction surface 234.

[0050] The light radiates from the intermediate light disc 20 in the direction of light propagation OA. Furthermore, additional auxiliary lines H1 to H5 are provided, which serve to calculate and illustrate angles and geometric conditions. The auxiliary line H1 runs parallel to the light propagation direction OA, so that the angle between H1 and the light coupling surface 232 corresponds to the inclination angle E or the demolding E. The auxiliary line H2 is the normal to the reflection surface 233 at the point of reflection of the light. Accordingly, the angle between a path of the light that strikes the reflection surface 233 after coupling via the light coupling surface 232 and the reflection surface 233 corresponds to the angle between a path of the light after reflection at the reflection surface 233 and the reflection surface 233 and is referred to in both cases as the reflection angle ϑ. The angle between the two paths mentioned is an auxiliary angle γ.The auxiliary line H3 is the normal to the light output surface 234 at the point of light output. The angle between the auxiliary line H3 and the path of the light traveling within the light module 23 and striking the light output surface 234 is a critical angle α', which is important with regard to Fresnel reflection. The auxiliary line H4 runs parallel to the light propagation direction OA at the point of light entry into the light module 23, so that the angle of draft E is again present here, as well as the angle of deflection A, which results from the deflection direction and draft E (as well as a sweep α). The auxiliary line H5 is the normal to the light coupling surface 232 at the point of light entry into the light module 23. The angle between the auxiliary line H5 and the path of the light entering the light module 23 is a further critical angle ε', which is important with regard to Fresnel reflection.This describes all the essential angles and relationships. In order to maintain a given direction of light propagation AR, certain geometric conditions can be changed while maintaining or increasing efficiency and reducing disruptive influences. Among other things, it must be ensured that the reflection angle ϑ maintains the angle of total internal reflection, especially for rays that are not ideally collimated. This was taken into account by calculating a divergence (Div) of the light rays, which in this case was set at 10° and 5°. In this case, the material of the light modules comprises PMMA with a refractive index of approximately 1.5 compared to the air surrounding the light module, which has a refractive index of approximately 1.0. The critical angle for total reflection is therefore approximately 42°, or approximately 32° or 37° when taking divergence into account.

[0051] As already mentioned, it is also crucial to consider Fresnel reflection, which can occur during the transition into and out of the light module 23. For this purpose, limit values ​​were defined for the critical angles α' and ε' in the calculation, so that a moderate amount of light is lost at most. The critical angle α' was defined as 25°, the critical angle ε' as 55°. Taking these conditions into account, the inventor was able to show that with a demoulding angle of approximately 10° and a sweep α in the range of 0° to approximately 45°, the deflection A should be in the range of 25° and 70°, which corresponds to the tables of Fig. 5c and Fig. 5d can be seen. List of reference symbols 1 lighting device 10 Light source 11 circuit board 20 Intermediate lens 21 first page 22 second page 23 light blocks 231 Light coupling section 232 light coupling area 233 Reflection surface 234 Light extraction section 235 light extraction area P Projection surface 30 aperture 40 Deflection optics / reflector 50 exterior light lens AR deflection direction A angle, deflection E Inclination angle / demolition OA Light output direction / optical axis VR predetermined direction α arrowhead α', ε' critical angle β, δ, ε, γ auxiliary angles ϑ reflection angle

Claims

[1] Lighting device (1) for a vehicle comprising: a light source (10) designed to generate light and emit it in a predetermined direction (VR), an intermediate light disc (20) which is designed to couple the light incident on a first side (21) of the intermediate light disc (20) with a deflection direction (AR), to guide it to a second side (22) of the intermediate light disc (20) and to radiate it via the second side (22) in a light output direction (OA), wherein the intermediate light disc (20) comprises a plurality of light modules (23) arranged one behind the other in the deflection direction (AR), wherein each of the plurality of light modules (23) comprises a light coupling section (231) arranged on the first side (21) of the intermediate light disc (20) and a light coupling section (234) arranged on the second side (22) of the intermediate light disc (20), wherein the light coupling section (231) has a light coupling surface (232) and a reflection surface (233) and the light coupling section (234) has a light coupling surface (235), wherein the light coupling surfaces (232) of the plurality of light modules (23) form a continuous projection surface (P) from the perspective of the light incident in the deflection direction (AR). [2] Lighting device (1) according to claim 1, wherein at least a part of the plurality of light modules (23) is formed by respective projections on the first side (21) of the intermediate light disc (20). [3] Lighting device (1) according to one of the preceding claims, wherein the plurality of light modules (23) are spaced apart from one another. [4] Lighting device (1) according to one of the preceding claims, wherein the light modules (23) are designed to produce a signature and / or a pattern on the second side (22). [5] Lighting device (1) according to claim 4, wherein at least a part of the light coupling sections (234) of the plurality of light modules (23) comprise respective projections, preferably step-shaped projections, on the second side (22) of the intermediate light disc (20). [6] Lighting device (1) according to claim 5, wherein regions of the intermediate light disc (20) on the second side (22) between adjacent projections of the light-coupling sections (234) are concealed by a diaphragm (30). [7] Lighting device (1) according to one of the preceding claims, wherein the lighting device (1) comprises a deflection optics (40) arranged in the predetermined direction, which is designed to deflect the light in the deflection direction (AR). [8] Lighting device (1) according to one of the preceding claims, wherein an angle, deflection, (A) between the light output direction (OA) and the deflection direction (AR) is between 25° and 70°, preferably 30° and 65° and particularly preferably between 35° and 60°. [9] Lighting device (1) according to one of the preceding claims, wherein an angle of inclination, demoulding, (E) between the light coupling surface (232) and the light output direction (OA) is between 3° and 20°, preferably 7° and 16° and particularly preferably between 10° and 13°. [10] Lighting device (1) according to one of the preceding claims, wherein the light modules (23) are designed to achieve total reflection of coupled-in light at the reflection surface (233).

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