VEHICLE WINDOW WITH A LIGHTING DEVICE

Abstract

A vehicle pane (3) with a light guiding layer (10) on the inner side of the pane and with a lighting device (4), which introduces light into the light guiding layer (10) by means of a light input coupling device, characterized in that the lighting device (4) has at least two LEDs (11), and in that each LED (11) is assigned a light input coupling element (12), via which light from the respective LED (11) is introduced into the light guiding layer (10).

Description

[0001] Vehicle window with a lighting device

[0002] The invention relates to a vehicle window with a light-guiding layer on the inside of the window and with an illumination device which introduces light into the light-guiding layer by means of a light coupling device.

[0003] A vehicle window of this type is known from DE 10 2020 109 338 B3. An illumination device for the vehicle window has a light source arranged on one end face of an elongated, rod-shaped light guide, made, for example, of PMMA or PC. The illumination device further comprises a strip-like light coupling element with a body that is wedge-shaped in cross-section. The light coupling element, which is made of a plastic material such as PMMA, as well as the light guide, extend over the length of the illumination device, with the light guide being arranged directly in front of a lateral, elongated end face of the light coupling element. The light coupling element is attached by adhesive to an inner side of a light-conducting layer formed by an inner pane of the multi-layer vehicle window.However, with such a long light coupling element, high stresses can occur in the bond, which can cause the bond to detach when temperatures change and the thermal expansion coefficients of the glass material of the light-guiding layer and the plastic material of the light coupling element differ.

[0004] The invention is based on the object of creating a vehicle window mentioned above that is improved with regard to the lighting device, as well as a method for producing such a vehicle window. This object is achieved according to the invention in the case of the vehicle window mentioned above in that the lighting device has at least two LEDs, and each LED is assigned its own light coupling element, via which light from the respective LED is introduced into the light-guiding layer.

[0005] The problem is also solved by a method having the features of claim 16 and by a method having the features of claim 17.

[0006] Advantageous embodiments of the invention are specified in the dependent claims.

[0007] In the vehicle window according to the invention, several units containing an LED and an associated light coupling element are arranged side by side in the longitudinal direction of the lighting device. In particular, several light coupling elements, such as approximately 10 to 40 light coupling elements, are arranged side by side in a row and preferably spaced apart from one another. The arrangement of a plurality of individual light coupling elements allows for improved adaptation to a curvature of the vehicle window in the longitudinal direction or in the direction of the longitudinally extending lighting device.This improved adaptation is particularly advantageous for light coupling elements made of glass, since a strip-like light coupling element made of hard glass material and formed in the length of the lighting device is less suitable for such adaptation to a curvature due to lower bendability or the difficulty of manufacturing curved or arched long glass light coupling elements or glass prisms.

[0008] Furthermore, the individual light coupling elements can be designed with their design and their light reflection surfaces to ensure optimized light guidance into the light-guiding layer.

[0009] According to a first embodiment, the light coupling elements are attached to the light-guiding layer as independent components. The light coupling elements manufactured as independent components are attached to the light-guiding layer in particular by means of adhesive bonding, encapsulation material, adhesive tape, or a holding or clamping device.

[0010] The light coupling elements are typically wedge-shaped or formed as prismatic bodies. The light coupling elements can be made of glass or a plastic material such as PMMA, PC, PU, ​​COP (cyclic olefin polymer) or COC (cyclic olefin copolymer).

[0011] The bonding material can be a pressure-sensitive adhesive, an optically clear liquid adhesive, EVA, PVB, TPU, an epoxy adhesive, or an acrylate adhesive. A holding or clamping device is attached to the vehicle window, e.g., by foaming the edge of the window. The holding or clamping device forms a solid mounting base for the direct or indirect attachment of the light coupling elements.

[0012] The size of the adhesive surface of a bond is thus limited to the size of the base surface of the light coupling elements. Particularly when the light-guiding layer is a glass inner pane of the vehicle window and the light coupling elements are made of a plastic material, the effects of different thermal expansion coefficients of the materials on the individual bonds are reduced to such an extent that detachment of the bonds of the individual light coupling elements can be prevented. The base surface of the light coupling element is also, in particular, a light output surface, through which light emitted by the LED is introduced or coupled into the light-guiding layer.

[0013] The materials of the light-coupling elements and the light-guiding layer can have identical or similar refractive indices. If the refractive indices match, the refractive indices of the fastening elements, such as adhesives, potting materials, or adhesive tape, are adapted to them or essentially match them. If the refractive indices of the light-coupling elements and the light-guiding layer differ, the refractive indices of the fastening elements can have the same value as the light-coupling elements or the light-guiding layer, or a value in between. The refractive index of the light-coupling elements, for example, ranges from 1.48 to 1.59. The refractive index of the light-guiding layer, for example, is 1.52.

[0014] In one embodiment, the light coupling elements are arranged on the light-guiding layer, for example, by foaming, gluing, and / or injection molding. Even if foaming is mentioned below, unless technically excluded or otherwise specified, the terms injection molding and / or gluing are also used. For ease of reading, however, the two other processes will not be explicitly mentioned below.

[0015] According to a further embodiment, the light coupling elements are foamed onto the light-guiding layer. The light coupling elements are injection-molded with a transparent foam material, such as PU, and preferably have high light refraction. UV-stabilized TPU, aliphatic TPU for high transparency, or polyisocyanates can also be used as foam materials.

[0016] The adhesion of the foam material and / or the sprayed material to the light-conducting layer, which may be made of glass, is ensured by the use of an adhesion promoter. Light- and UV-resistant primers are preferably used as adhesion promoters. Transparent, age-resistant primers, for example, are used as adhesion promoters, ensuring colorfastness and preventing color shift.

[0017] To protect the light coupling elements, e.g., against aging due to UV exposure or as mechanical protection, a protective layer can be applied to the light coupling element. Materials that are particularly suitable for this purpose include those mentioned for the manufacture of the light coupling elements, e.g., aliphatic materials due to their good UV resistance. Such foamed light coupling elements can be customized. They can, for example, be formed with undercuts or holders intended for attaching the LEDs, e.g., via a carrier supporting the LEDs. Additional components for attaching the LEDs can be largely or completely dispensed with.

[0018] The light coupling elements are advantageously foamed in parallel with a foaming process, in which the edge of the glass pane is foamed, for example, using black polyurethane. This allows for optimized cycle times. Additional cleaning processes are not required. This eliminates the need to handle complex components such as the light coupling elements as independently mounted components or additional components such as additional fastening components and the like.

[0019] According to a further embodiment, the light coupling elements are formed integrally with the light-guiding layer. A light-guiding layer made of clear glass, for example, thus contains the light coupling elements molded from the same glass material during production.

[0020] This integral or integrated formation of the light coupling elements with the light-guiding layer eliminates the otherwise necessary coupling or fastening of each individual light coupling element to the light-guiding layer. This also applies to light coupling elements foamed onto the light-guiding layer.

[0021] A light-guiding layer made of a plastic material, in particular as stated above for the light-coupling elements, contains the molded, foamed or injection-molded light-coupling elements made of the same plastic material or of a plastic material with a light refractive index that is the same or similar to that of the light-guiding layer.

[0022] According to a preferred embodiment, each light coupling element has a base surface and each light coupling element is optically connected via its base surface to an inner surface of the light-guiding layer directed towards a vehicle interior. In a light coupling element formed as a stand-alone component, the base surface is a real outer surface of the light coupling element. In a light coupling element foamed onto the light-guiding layer, the base surface is a contact surface of the foamed light coupling element. In a light coupling element formed integrally with the light-guiding layer, the base surface is a fictitious surface at the transition from the light coupling element to the light-guiding layer, wherein the fictitious surface is substantially parallel to the adjacent surface of the light-guiding layer.

[0023] The use of a large number of individual light coupling elements, each of which is formed with a short length in the longitudinal direction of their row arrangement, thus enables improved adaptation to the curvature of the vehicle window due to the individual design, the individual molding or the individual fastening to the light-guiding layer.

[0024] For those light guide elements that are optically coupled as independent components via their base surface, an immersion oil or a capillary oil can be used to ensure optically perfect coupling.

[0025] The vehicle window can be formed such that it has an outer pane and an inner pane, e.g., a clear glass pane, connected to the outer pane by means of a connecting layer such as a hot-melt adhesive film. The inner pane expediently forms the light-guiding layer. However, the light-guiding layer can also be formed by another layer, such as a film or the like.

[0026] The inner pane expediently contains a structure that visually stands out when light shines into the inner pane. The structure is produced, for example, by screen printing or printing on the inner pane. The structure can represent, for example, a pattern, an emblem, or lettering, or combinations thereof. Each light coupling element expediently contains an LED surface directed toward an adjacent pane edge. The respective LED is positioned in front of or on the LED surface. The LED surface is preferably aligned perpendicular to the base surface, via which the light coupling element is coupled, attached, or bonded to the light-conducting layer.

[0027] Preferably, each light coupling element, in particular a wedge-shaped or prismatic one, contains opposing oblique side edges at the edges of its base surface, which – starting from a wedge tip of the light coupling element – ​​approach each other toward the LED surface. The oblique side edges are each arranged at an acute angle to an extension of the LED surface. The size of the acute angle is in the range of, for example, 10° to 70° and in particular in a range of 30° to 45°.

[0028] According to a further preferred embodiment, it is provided that each in particular wedge-shaped or prismatic light coupling element has on each oblique side edge an oblique reflection surface emanating from the oblique side edge, which is arranged perpendicular to the base surface.

[0029] According to a further alternative embodiment, each light coupling element, in particular a wedge-shaped or prismatic one, has an oblique reflection surface extending from the oblique side edge at each oblique side edge, which has an inclined side reflection surface extending from the oblique side edge and arranged at an acute angle to the base surface. The size of the acute angle is in a range of, for example, 35° to 70°.

[0030] The light reflection in the light coupling element, and thus the quality of the illumination, can be adjusted as desired by designing the angle of the beveled side edges and the inclination of the additional side reflection surfaces. By designing the light coupling element with such features, for example, faceted side reflection surfaces and beveled reflection surfaces, material that would otherwise be required in these areas is saved. In addition to saving material, potential thermal expansion stresses in the light coupling element are reduced due to the smaller amount of material.

[0031] For such light coupling elements, which are attached to the light-guiding layer as independent components, a preferred embodiment provides that the LEDs are attached to a carrier, and that the light coupling elements are positioned and attached to the carrier in association with the respective LED. The carrier is preferably a PCB (printed circuit board). The power supply and control of the LEDs can also be provided via the carrier.

[0032] Preferably, a lighting module comprising the carrier with the LEDs and the light-coupling elements is attached to the light-guiding layer by means of the light-coupling elements. The carrier does not require any separate attachment or bonding to the light-guiding layer. The attachment is preferably achieved by means of the above-described attachment of the light-guiding elements to the light-guiding layer, in particular by bonding the light-guiding elements to the light-guiding layer. Thus, only one bonding process is required for bonding the light-coupling elements.

[0033] Each light coupling element expediently contains at least one fastening element with which the light coupling element can be attached to the support. In the case of a light coupling element manufactured as a plastic injection-molded part, the fastening element is expediently an injection-molded component. However, the fastening element can also be another part of the light coupling element or a part attached to it.

[0034] According to a preferred embodiment, the light coupling elements hold the carrier substantially parallel to the inner surface of the light-guiding layer. The LEDs radiate light emitted laterally (so-called "side LEDs") via the LED surfaces into the light coupling elements. With this design, the LEDs can be positioned close to the light-guiding layer, since no holder is required between the LEDs and the light-guiding layer. A parallel arrangement of the carrier should not be understood in the sense of a strictly mathematical parallelism. Rather, a parallel arrangement of the carrier should also be understood as an arrangement at a certain inclination to the light-guiding layer, for example, at an angle of up to 15° or 20°.

[0035] It is therefore particularly preferred if the LEDs are arranged between the carrier and the light-guiding layer, adjacent to the light-guiding layer, or directly on the light-guiding layer. This reduces the required installation space height. Furthermore, the light coupling elements can be used with a lower height.

[0036] The carrier expediently covers the light coupling elements at least partially on the underside. This allows for simple and secure attachment of the light coupling elements to the carrier. This also reduces unwanted light coupling in the area of ​​the LED or the light coupling elements.

[0037] According to a further alternative embodiment, the light coupling elements hold the carrier substantially perpendicular to the inner surface of the light-guiding layer, and the LEDs radiate light emitted from the top side (so-called "top LEDs") via the LED surfaces into the light coupling elements. In this embodiment, too, the LEDs can be positioned close to the light-guiding layer or directly on the light-guiding layer, since no holder is required between the LEDs and the light-guiding layer. The LEDs can, for example, be arranged on an upper edge of the carrier adjacent to the light-guiding layer. A perpendicular arrangement of the carrier to the light-guiding layer is not limited to an arrangement at an exact right angle. Rather, a perpendicular arrangement of the carrier is also understood to mean an arrangement deviating from a right angle, for example at an angle of up to 15° or 20°.A cover is conveniently attached to the carrier. The cover, which covers the lighting module, also serves as a screen, which can, for example, shield stray light emanating from the light coupling elements.

[0038] According to a preferred embodiment, the cover is held or attached to the light-guiding layer. The cover holds the carrier, with the light-coupling elements arranged thereon, correctly positioned on the light-guiding layer. The cover can hold the carrier elastically connected in such a way that the cover, in its position on the light-guiding layer, keeps the carrier elastically pre-tensioned against the light-guiding layer. This supports the optically correct positioning of the light-coupling elements on the light-guiding layer.

[0039] According to an alternative embodiment, the cover is attached to the carrier and held in position by the carrier on the light-guiding layer. The carrier is attached to the light-guiding layer by means of the light coupling elements. Since the cover is attached to the carrier, no other fastening for the cover is required.

[0040] Preferably, the cover is formed with a longitudinal curvature that is adapted to, and in particular coincides with, a curvature of the light-guiding layer or the vehicle windshield. If the cover is sufficiently rigid, it can correspondingly pre-curve the support carrying the light coupling elements when the support is attached to the light-guiding layer together with the cover.

[0041] A seal is advantageously provided between the cover and the light-conducting layer. The seal is preferably manufactured together with the cover using a two-component injection molding process. However, the seal can also comprise separate sealing elements.

[0042] According to a preferred embodiment, each arranged light coupling element (e.g., foamed) or formed integrally with the light-guiding layer has a holder, and the holders position the carrier carrying the LEDs on the light coupling elements. The holder is expediently formed on the light coupling element on its upper side opposite the base surface. The holder is shaped, for example, as a plug-in unit for a carrier formed, for example, by a PCB, which has a plurality of LEDs.

[0043] The foamed light coupling elements are expediently connected to one another via connecting webs which are formed during foaming when the foam material flows from one cavity of one light coupling element via a distribution channel segment to the next cavity of the adjacent light coupling element.

[0044] In the method according to the invention for producing such a vehicle window with a lighting device, it is provided that a carrier with LEDs attached thereto is provided. Furthermore, the light coupling elements are each firmly connected to the carrier in association with one of the LEDs. Finally, a lighting module comprising the carrier with the LEDs and the light coupling elements is attached to the light-guiding layer with optical coupling of the light coupling elements to the light-guiding layer by either attaching the light coupling elements to the light-guiding layer or attaching a cover, which is connected to the carrier and covers the lighting module, to the light-guiding layer, thereby positioning and fixing the carrier.This process simplifies assembly, as only the light-guiding elements need to be attached or bonded to the light-guiding layer, and the carrier itself requires no additional independent or direct attachment to the light-guiding layer. The light-guiding elements or prisms can be mounted on the carrier using a placement robot.

[0045] In a modified alternative procedure, the individual light-guiding elements or prisms can first be attached or glued to the light-guiding layer using a placement robot. The carrier containing the LEDs is then positioned on the light-guiding elements or prisms and firmly connected to them. In a further preferred method for producing such a vehicle window with a lighting device, it is provided that the light-guiding layer is formed with integrally molded light-coupling elements or that the light-coupling elements are foamed onto the light-guiding layer. Furthermore, it is provided that the light-coupling elements are provided with holders for a carrier carrying the LEDs. Finally, the carrier is attached to the holders. The LEDs are positioned on the light-coupling elements.

[0046] The vehicle window according to the invention can be any pane of vehicle glazing, for example a cover arranged fixedly or movably in a roof opening, a glazing of a roof module or panoramic roof or also a side window, a rear window or a windscreen.

[0047] The invention will be explained in more detail below using exemplary embodiments of a vehicle window according to the invention with reference to the drawing. It shows:

[0048] Fig. 1 shows an isometric view of a vehicle roof with a vehicle window according to the invention;

[0049] Fig. 2 shows a cross-sectional view of an edge region of the vehicle window with a lighting device having an LED and an associated light coupling element;

[0050] Fig. 3 shows a plan view of the lighting device with several LEDs and associated light coupling elements;

[0051] Fig. 4 shows a side view of the lighting device with the LED and the associated light coupling element of Fig. 2; Fig. 5 shows a cross-sectional view of a second embodiment of the lighting device;

[0052] Fig. 6 shows a plan view of the lighting device of Fig. 5 with several LEDs and associated light coupling elements;

[0053] Fig. 7 shows a side view of the lighting device of Fig. 5;

[0054] Fig. 8 shows an isometric view of an embodiment of a light coupling element;

[0055] Fig. 9 shows an isometric view of several of the light coupling elements shown in Fig. 8 in a row arrangement;

[0056] Fig. 10 shows a plan view of four rows of differently designed light coupling elements;

[0057] Fig. 11 shows a cross-sectional view of the vehicle window with a foamed light coupling element;

[0058] Fig. 12 shows an isometric view of several light coupling elements foamed onto the vehicle window;

[0059] Fig. 13 shows a schematic plan view of a vehicle window with several light coupling elements, with edge foaming and with associated sprue channels of a foaming tool;

[0060] Fig. 14 shows a plan view of the underside of a lateral edge section of the vehicle window with a row of molded-on light coupling elements; and Fig. 15 shows a plan view of the underside of a lateral edge section of a cover containing the vehicle window of Fig. 14.

[0061] A vehicle such as a passenger car comprises a vehicle roof 1 (Fig. 1 ) with a roof opening 2 in which a vehicle window 3 is arranged, which e.g.

[0062] B. is fixedly arranged in the roof opening 2 or is formed as a cover that is movably mounted in the roof opening 2 by means of a bearing device and adjustable between a closed position and ventilation or open positions in a manner known per se. The vehicle window 3 can also be a fixed part or section of a roof module or panoramic roof. The vehicle window 3 has a lighting device 4, which is arranged on the inside 5 of the window and preferably along a respective side edge 6 of the vehicle window 3.

[0063] The vehicle window 3 comprises (see Figs. 2 and 3) an outer pane 7, an inner pane 8, and a connecting layer 9 that connects the outer pane 7 and the inner pane 8 to each other and contains, for example, a laminate layer, laminate film, or hot-melt adhesive film. The outer pane 7 is, for example, a tinted glass pane. The inner pane 8 is, in particular, a transparent glass pane or clear glass pane that forms a light-conducting layer 10.

[0064] The lighting device 4 has a plurality of LEDs 11 and a plurality of light coupling elements 12, wherein each LED 11 and a light coupling element 12 form a lighting unit 13. A plurality of such lighting units 13 are arranged next to one another in a row and preferably spaced apart from one another. The distance between two adjacent LEDs 11 is, for example, 30 mm. The lighting device 4 on the side edge 6 of the vehicle window 4 thus comprises, for example, approximately 20 to 30 lighting units 13. The length of an individual light coupling element 12 in the longitudinal direction of the row-like arrangement is, for example, approximately 25 to 28 mm. This length specification refers in particular to the front edge of the wedge-shaped or prismatic light coupling element 12, which tapers to a point as the wedge tip 37. The light coupling element 12 represents an optical prism and is, for example, a plastic injection-molded part.The light coupling element 12 has a base surface 14 and an LED surface 15, which is preferably arranged perpendicular to the base surface 14 and assigned to the LED 11. According to a first embodiment (Figs. 2 to 4), the LEDs 11 are firmly attached to a carrier 16, which is, for example, a PCB (printed circuit board), preferably designed as a flat, strip-shaped component, and via which the power supply to the LEDs 11 and their control takes place. In its installed position, the flat carrier 16 is arranged approximately parallel to the inner side 5 of the pane and to the inner surface 17 of the inner pane 8 and at a distance from the latter. In this embodiment, the LEDs 11 are LEDs that emit light laterally and thus, in their position on the carrier 16, in which they are located on the side of the carrier 16 facing the light-guiding layer 10, emit the light parallel to the carrier 16.

[0065] The light coupling element 12 has fastening elements 18 formed during injection molding, which are formed, for example, as pins with clips and which protrude from the light coupling element 12 on its upper side opposite the base surface 14. The light coupling element 12 has, for example, four of these fastening elements 18, with two of the fastening elements 18 being formed on each of the two sides of the light coupling element 12 via short arms 19.

[0066] The support 16 has four holes 20 assigned to each LED 11 and to the four fastening elements 18. The light coupling element 12 is arranged and fastened to the support 16 inwardly next to the LED 11—inwardly relative to the side edge of the vehicle window in the transverse direction or y-direction—by means of the fastening elements 18, which can be inserted into the holes 20 in a snap-in manner, so that the light coupling element 12, with its LED surface 15, is directly adjacent to the LED 11.

[0067] A lighting module 21, which comprises a carrier 16 with a plurality of lighting units 13, each containing an LED 11 and a light coupling element 12, is attached to the light-guiding layer 10 as a unit by attaching each light coupling element 12 via its base surface 14 to the inner surface 17 of the inner pane 8 by means of an adhesive bond 22 (Fig. 2), e.g., a transparent adhesive or a transparent adhesive tape. Each light-guiding element 12 guides light radiated by the LED 11 via at least one upper-side reflection surface 23 opposite the underside base surface 14 into the light-guiding layer 10, in which the light, via further internal reflection, strikes a light coupling structure 24, e.g., a print on the light-guiding layer 10, and is emitted from this structure toward the vehicle interior.

[0068] The arrangement of several individual short or narrow light coupling elements 12 or prisms has the advantage that stresses in the respective adhesive bonds of the individual light coupling elements 12 or prisms, which can occur during temperature changes and during different thermal expansions of the glass pane, the light-conducting layer 10 and the individual plastic prisms as light coupling elements 12, are significantly reduced in comparison with stresses in the adhesive bond of a long light coupling element, over the length of which many LEDs are arranged, which radiate their light into this one light coupling element.

[0069] In particular in the case of vehicle windows 3 which are curved in the longitudinal direction, the arrangement of several individual short light coupling elements 12 or prisms is advantageous, since these short light coupling elements 12 or prisms can adapt better to such a curvature in comparison with a single long light coupling element or prism.

[0070] Furthermore, the LEDs 11 can be arranged very close to the light-guiding layer 10 via the carrier 16, since a fastening element or carrier between the LED 11 and the light-guiding layer 10 is not required. This allows the required height of the light coupling element 12 or prism perpendicular to the light-guiding layer, or the height of the LED surface 15, to be reduced.

[0071] Furthermore, the respective mutual arrangement of the LED 11 and the associated light coupling element 12 or prism on the one carrier 16 increases the positioning accuracy and reduces tolerances that may occur in an otherwise separate mounting of the LED and the associated light coupling element or prism on a respective carrier component.

[0072] When mounting the lighting module 21 on the light-guiding layer 10, only the bonding 22 of the light coupling elements 12 or prisms to the light-guiding layer 10 is required. Otherwise, additional fastening of the LEDs to the light-guiding layer 10 is not required.

[0073] The light coupling elements 12 or prisms can be attached to the support 16 by adhesive bonding or other fastening means instead of by means of the fastening elements 18, e.g., in the case of light coupling elements 12 made of glass or glass prisms. The attachment can also be achieved by means of encapsulation material, adhesive tape, or a holding or clamping device.

[0074] A cover 25 for the lighting module 21 is, for example, trough-shaped and has a bottom wall 26 and two side walls 27 and 28. On the inside of the bottom wall 26, upwardly directed fastening elements 29 are arranged or formed, which are intended to engage in associated openings 30 in the carrier 16. To fasten the cover 25, the fastening elements 29, which have, for example, clips, engage in the openings 30 and hold the cover 25 fastened to the carrier 16 by means of clamping or locking, in particular in a form-fitting manner. Instead of using fastening elements 29, the cover 25 can also be fastened by gripping the edge of the carrier 16 in a clamping or locking engagement. The two side walls 27 and 28 have seals 31 and 32 on their two free edges, which lie tightly against the light-guiding layer 10. The cover 25 is in particular a plastic injection-molded part in which the seals 31, 32 are formed in a 2K injection-molding process.

[0075] The cover 25 can expediently be shaped with a curvature along its longitudinal extent that corresponds to the curvature of the associated vehicle window. According to a modified embodiment (see Figs. 5 to 7), the carrier 16', expediently also a PCB, is upright in its installed position and arranged essentially vertically to the light-guiding layer 10. The LEDs 11' are attached to the carrier 16' in the region of its upper edge 33 adjacent to the light-guiding layer 10, on its side facing inward toward the cover. In this embodiment, the LEDs 11' are LEDs that emit light from their upper side and thus, in their position on the carrier 16', emit light perpendicular to the carrier 16' and parallel to the light-guiding layer 10.

[0076] Each light coupling element 12 is attached to the carrier 16', for example, via two angled mounting arms 34 such that its LED surface 15 directly borders the LED 11' for light irradiation from the LED 11'. In this embodiment, too, the mounting arms 34 can engage in openings or bores 20' of the carrier 16' via clip connections.

[0077] During assembly, the lighting module 21' is attached to the light-guiding layer 10 by means of simultaneous adhesive bonds 22 of the individual light coupling elements 12.

[0078] The cover 25' is secured via fastening elements 29', which, for example, comprise clips, engage in openings 30' in the support 16', and hold the cover 25' fastened to the support 16' by means of clamping or locking, in particular in a form-fitting manner. The fastening elements 29' are arranged or molded, for example, on the outer side wall 27' of the cover 25' and point inward. The cover 25' has seals 31, 32 on the edges of the side walls 27' and 28', corresponding to the previous embodiment.

[0079] The advantages of this embodiment shown in Figs. 5 to 7 essentially correspond to those of the first embodiment shown in Figs. 2 to 4.

[0080] In both embodiments, due to the arrangement of the LEDs 11, 1T near the light-guiding layer 10 or directly adjacent to the light-guiding layer 10, the height of the light-coupling element 12 or prism in the region of the LED surface 15 adjacent to the LED, and thus also the width or length of the light-coupling element 12 or prism, can be reduced. Thus, the number of individual light-coupling elements 12 can be increased over the length of the illumination device 4, which can improve the quality of the illumination.

[0081] The following description of the light coupling elements 12 relates to those light coupling elements which are attached to the light-guiding layer 10 as independent components, for example by gluing, or which are foamed, injection-molded or glued to the light-guiding layer 10 as foam or injection-molded elements, or which are also formed integrally with the light-guiding layer 10, in which case the base surface 14 of the light coupling element 12 is a fictitious surface parallel to the surface of the light-guiding layer 10 or to the inner side 5 of the pane.

[0082] Each light coupling element 12 (see Figs. 8 to 10) is preferably wedge-shaped in side view (see Fig. 2) with a wedge tip 37 opposite the LED surface 15. The LED surface 15 is arranged on the incident radiation side of the light coupling element 12, in particular at right angles to the base surface 14. The light coupling element 12 has a side edge 35 on each of its two flanks. The two opposite side edges 35 are, for example, parallel to one another (Fig. 10a), so that the light coupling element 12 thus has a rectangular base surface 14. The side edges 35 are contained in the two wedge-shaped and mutually parallel parallel side surfaces. These parallel side surfaces likewise form reflection surfaces for light radiated by the LED 11 into the light coupling element 12. The LED surface 15 extends in its width between the two side edges 35 over the entire width of the light coupling element 12 or.over its length in the direction of the row arrangement. The individual light coupling elements 12 with the parallel side edges 35 are arranged in the row arrangement of Fig. 10a, in which they are connected to the carrier 16 or arranged or glued to the light-guiding layer 10, at a respective distance between their side edges 35 of, for example, at least 1 mm or 3 mm (Fig. 10d). The light-guiding element 12 can be formed with an LED surface 15 that is reduced in its width direction (Figs. 8, 9 and 10b to 10d). The light-guiding element 12 designed in this way is beveled, starting from this narrow LED surface 15, towards each side edge 35 at an angle α relative to the LED surface 15. As a result, a particularly planar oblique reflection surface 36 is formed on both sides of the LED surface 15. The oblique reflection surface 36 extends to the correspondingly shortened side edge 35 or to the shortened wedge-shaped parallel side surface.Each oblique reflection surface 36 forms an oblique side edge 38 at the transition to the base surface 14. The angle a is the external angle between the oblique reflection surface 36 and the oblique side edge.

[0083] 38 and an imaginary extension 15' of the plane of the LED surface 15. The angle a is, for example, 30° (Fig. 10b and 10d) or 45° (Fig. 10c).

[0084] Furthermore, each light-guiding element 12 can have an inclined side reflection surface on its two lateral flanks in the region of the oblique side edges 38

[0085] 39. The side reflection surface 39 extends from the beveled side edge 38 at an acute angle β, measured in the plane of the LED surface 15 (see Fig. 8), to the reflection surface 23. The angle β lies in a range of, for example, 35° to 70°. The side reflection surface 39 thus has an approximately triangular shape. Light radiated by the LED 11 into the light-guiding element 12 is reflected via the reflection surface 23 as the main reflection surface and via the two oblique reflection surfaces 36 or via the two additional side reflection surfaces 39 and coupled into the light-guiding layer 10. The light reflection in the light-coupling element 12 and thus the quality of the illumination can be adjusted by specifying the angle α of the bevels or the oblique reflection surfaces 36 as well as the angle β of the inclination of the side reflection surfaces 39.

[0086] Ambient lighting can be provided by the two lighting devices 4, which are arranged symmetrically with respect to a vertical longitudinal roof center plane in the region of the respective side edge of the vehicle window 3. In a modified embodiment of the vehicle window 3 (see Figs. 11 to 15), the light coupling elements 12 are foamed onto the light-guiding layer 10 on the inside 5 of the window. The light coupling elements 12 are arranged next to one another in a row (see Fig. 14) and are preferably connected to one another via connecting webs 40 (Fig. 12). Two adjacent light coupling elements 12 are each connected to one another via such a connecting web 40. A vehicle window 3 is arranged in a foaming tool for foaming the light coupling elements 12, which tool has a cavity 41 (Fig. 13) for edge foaming 42 of the vehicle window 3.The cavity 41 is to be filled with foam material, e.g. black standard polyurethane, via a sprue 43 provided in the tool.

[0087] A further cavity 44 of the foaming tool contains a mold cavity 45 for each light coupling element 12. A sprue 46 leads in the tool to a first mold cavity 45. A distribution channel 47 connects the further mold cavities 45 to one another, with two adjacent mold cavities 45 being connected to one another via a respective channel segment 48 of the distribution channel 47. The injected foam material forms a light coupling element 12 foamed onto the light-guiding layer 10 in each mold cavity 45 and a respective connecting web 40 in the channel segments 48. The channel segments 48 have a shape such that each connecting web 40 is preferably in the form of a flat strip (Fig. 12) which is foamed onto the inner surface of the light-guiding layer 10.

[0088] The light coupling elements 12 (Fig. 11) are expediently formed in principle with a shape as described above (see in particular Figs. 8 to 10). Each light coupling element 12 further comprises a holder 49, which is formed on its upper side or upper-side reflection surface 23 opposite the base surface 14. The holder 49 is formed, for example, as a plug-in unit for a carrier 16, for example a PCB, which contains a plurality of LEDs 11. The LEDs 11 are arranged next to one another and in series, as well as in association with the LED surfaces 15 of the light coupling elements 12, on the carrier 16, so that when the carrier 16 is plugged onto the holders 49 of the light coupling elements 12, the correct association of the LEDs 11 with the LED surfaces 15 is established. The holder 49 is, for example,formed as a peg-shaped or mushroom-shaped elevation which engages in an opening 50 of the carrier 16 and expediently fixes the carrier 16 with a releasable locking engagement, so that, for example, defective LEDs 11 can be replaced together with the carrier 16.

[0089] A vehicle roof often has an upwardly raised curvature. A vehicle window 3 of the vehicle roof, which has a corresponding curvature, is curved in the longitudinal direction (x-direction) along the row of light coupling elements 12. The elongated, strip-shaped carrier 16, which contains a plurality of LEDs 11, is fastened to the light coupling elements 12 via the holders 49. The carrier 16 adapts to the curvature of the vehicle window 3 along the row of light coupling elements 12 with an approximately arcuate deformation. This arcuate deformation causes at least some LEDs 11 to abandon their mutually parallel alignment and to be aligned with a slight mutual angular offset. Accordingly, at least some associated light coupling elements 12 are arranged offset from one another. Fig.13 shows schematically and by way of example a wasteful arrangement of the two outer light coupling elements 12 based on the associated mold cavities 45.

[0090] An elongated cover 51 (Fig. 11 ) of the light coupling elements 12 is fastened on the one hand at its inner edge 52 inward of the pane in front of the wedge tip 38 of the light coupling elements 12, e.g. by means of an adhesive 53, and on the other hand is held at its outer edge 54 in a groove 55 of the edge foam 42, e.g. by means of a clamping engagement.

[0091] Fig. 14 shows the vehicle window 3 with a series of light coupling elements 12, which are foamed onto the inside of the window in the longitudinal direction or x-direction inward of the edge foam 42, which is formed, for example, from a black-colored polyurethane. Fig. 15 shows the underside of a cover 56 of a vehicle roof with a cover frame 57, which is connected to the vehicle window 3.

[0092] The light coupling elements 12 are preferably made of a transparent polyurethane. The foam material of the light coupling elements 12 and the material of the light-guiding layer 10 expediently have the same or similar optical properties. PU-based foam materials are preferably suitable, which exhibit high transparency, low yellowing due to aging, and a refractive index adapted to the light-guiding layer 10. For example, a refractive index of approximately 1.5 for thermoplastic polyurethane (TPU) is very similar to the refractive index of the glass used for the light-guiding layer 10.

[0093] Reference symbols

[0094] Vehicle roof 31 Seal roof opening 32 Seal vehicle window 33 Upper edge of lighting device 34 Fastening arm inside window 35 Side edge

[0095] Side edge 36 oblique reflection surface

[0096] Outer pane 37 Wedge tip Inner pane 38 Beveled side edge

[0097] Connecting layer 39 Side reflection surface Light guide layer 40 Connecting bridge

[0098] LED 41 cavity

[0099] Light coupling element 42 Edge foaming Lighting unit 43 Sprue base area 44 Cavity

[0100] LED area 45 Mold cavity support 46 Sprue channel

[0101] Inner surface 47 distribution channel

[0102] Fastener 48 Channel segment arm 49 Bracket

[0103] Hole 50 Opening lighting module 51 Cover bonding 52 Inner edge reflection surface 53 Bonding light output structure 54 Outer edge

[0104] Cover 55 Groove bottom wall 56 Cover side wall 57 Cover frame side wall fastening element

[0105] opening

Claims

25 Patent claims 1. Vehicle windscreen (3) with an inner light-guiding layer (10) and with a lighting device (4) which introduces light into the light-guiding layer (10) by means of a light coupling device, characterized in that the lighting device (4) has at least two LEDs (11) and that each LED (11) is assigned a light coupling element (12) through which light from the respective LED (11) is introduced into the light-guiding layer (10).

2. Vehicle windscreen (3) according to claim 1 , characterized in that the light coupling elements (12) - are attached to the light guide layer (10) as independent components, in particular by means of bonding, potting material, adhesive tape or a holding or clamping device, or - are foamed and / or injection-molded onto the light-guiding layer (10) or - are formed integrally with the light-guiding layer (10).

3. Vehicle windscreen (3) according to claim 1 or 2, characterized in that each light coupling element (12) has a base surface (14) and is optically connected via its base surface (14) to an inner surface (17) of the light guide layer (10) directed towards a vehicle interior.

4. Vehicle window (3) according to one of claims 1 to 3, characterized in that each light coupling element (12) has an LED surface (15) directed towards an adjacent window edge (6) and the respective LED (11 ) is positioned on the LED surface (15). Vehicle windscreen (3) according to claim 3 or 4, characterized in that each, in particular wedge-shaped or prismatic, light coupling element (12) has opposing inclined side edges (38) at the edges of the base surface (14), which approach each other towards the LED surface (15). Vehicle windscreen (3) according to claim 5, characterized in that each, in particular wedge-shaped or prismatic, light coupling element (12) has at each inclined side edge (38) - an oblique reflection surface (36) extending from the sloping side edge (38) and arranged perpendicular to the base surface (14), or - an inclined side reflection surface (39) extending from the sloping side edge (38), which is arranged at an acute angle (β) to the base surface (14). Vehicle windscreen (3) according to one of claims 1 to 6, characterized in that the LEDs (11) are attached to a carrier (16) and the light coupling elements (12) are positioned and attached to the carrier (16) in association with the respective LED (11). Vehicle windscreen (3) according to claim 7, characterized in that a lighting module (21) comprising the carrier (16) with the LEDs (11) and the light coupling elements (12) is attached to the light-guiding layer (10) by means of the light coupling elements (12). Vehicle windscreen (3) according to claim 7 or 8, characterized in that each light coupling element (12) has at least one fastening element (18) for attachment to the carrier (16). Vehicle windscreen (3) according to one of claims 7 to 9, characterized in that the light coupling elements (12) hold the carrier (16) substantially parallel to the inner surface (17) of the light-guiding layer (10) and that the LEDs (11) emit light laterally from them via the LED surfaces (15) into the light coupling elements (12). Vehicle windscreen (3) according to one of claims 7 to 10, characterized in that the LEDs (11) are arranged between the carrier (16) and the light-guiding layer (10) and adjacent to the light-guiding layer (10) or directly on the light-guiding layer (10). Vehicle window (3) according to one of claims 7 to 9, characterized in that the light coupling elements (12) hold the carrier (16') substantially perpendicular to the inner surface (17) of the light guiding layer (10) and that the LEDs (1 T) emit light from their upper surface via the LED surfaces (15) into the light coupling elements (12).Vehicle windscreen (3) according to any one of claims 7 to 12, characterized in that a cover (25, 25') is connected to the carrier (16, 16'). Vehicle windscreen (3) according to claim 13, characterized in that the cover (25, 25') is held or attached to the light-guiding layer (10) and holds the carrier (16, 16') with the light coupling elements (12) positioned on the light-guiding layer (10), or that the cover (25, 25') is attached to the carrier (16, 16') and is held in position on the light-guiding layer (10) by the carrier (16, 16'), wherein the carrier (16, 16') is attached to the light-guiding layer (10) by means of the light coupling elements (12). 28 Vehicle window (3) according to one of claims 2 to 8, characterized in that each foamed, injected, glued or integrally formed light coupling element (12) has a holder (49) and the holders (49) position the carrier (16) supporting the LEDs (11) on the light coupling elements (12). Method for manufacturing a vehicle windscreen (3) with a lighting device (4) according to one of claims 1 to 14, characterized in that a carrier (16, 16') with LEDs (11) attached thereto is provided, that the light coupling elements (12) are each firmly connected to the carrier (16, 16') in association with one of the LEDs (11), and that a lighting module (21) comprising the carrier (16, 16') with the LEDs (11) and the light coupling elements (12) is attached to the light-guiding layer (10) by optically coupling the light coupling elements (12) to the light-guiding layer (10). - the light coupling elements (12) are attached to the light guiding layer (10) or - a cover (25, 25') connected to the carrier (16, 16') and covering the lighting module (21), is attached to the light-guiding layer (10) and thereby positions and fixes the carrier (16, 16'). Method for manufacturing a vehicle window (3) with a lighting device (4) according to one of claims 1 to 8 and 15, characterized in that the light-guiding layer (10) is formed with integrally molded light coupling elements (12) or that the light coupling elements (12) are foamed onto the light-guiding layer (10), that the light coupling elements (12) are provided with holders (49) for a carrier (16) supporting the LEDs (11), and 29 that the carrier (16) is attached to the supports (49), with the LEDs (11) being positioned on the light coupling elements (12).