Illuminated vehicle garnish

Abstract

The present invention relates to an illuminated vehicle glazing having: (i) an outer glass pane (11); (ii) an inner glass pane (12) acting as a light guide layer, wherein (iii) the first and second glass panes (11, 12) are laminated together via at least a first plastic intermediate layer (14); (iv) light decoupling means (13) provided between the first plastic intermediate layer and the inner glass pane (12); (v) a masking band provided along the periphery of the inner surface (P2) of the outer glass pane (12) and / or the inner surface (P4) of the inner glass pane; and (vi) a light source provided on or in the vicinity of the masking band and arranged on the inner surface (P4) of the inner glass pane (12). According to the invention, at least one coupling element (30) for coupling the light emitted from the light source (20) into the inner glass pane is provided in the vicinity of the light source in a zone where no masking band is present, is substantially joined to the inner glass pane (11) on its inner surface (P4), and the light source (20) faces the side edge (310) of the coupling element.

Description

Technical Field

[0001] The present invention relates to a lighting glazing unit for a vehicle, and more particularly to a lighting glazing that forms a part of an automobile roof. Such vehicle windows are conventionally known and can be used particularly in the field of vehicle roofs.

Background Art

[0002] In the prior art, lighting vehicle glazings having a glass pane acting as a light guide layer are known. Also known are glazing roofs provided with a light source coupled to the light guide layer. For the purpose of the safety of vehicle occupants, the glazing is a laminated glazing provided with an outer and an inner glass pane. It is well known that a coupling element is provided at the edge of the inner glass pane acting as a light guide layer. Thus, the inner glass pane is generally smaller than the outer glass pane in order to have sufficient space for fixing the coupling element in a pressure contact state with respect to the edge of the inner glass pane. Thereby, the light emitted by the light source can be coupled through the edge of the light guide layer.

[0003] Also, from European Patent No. 3463869, glazings having holes provided therein with a light source are known, which makes the manufacture of the glazing difficult.

[0004] Furthermore, from WO 2021 / 198262 pamphlet, it is known to use plastic couplings on the inner surface of the roof. The coupling element described in WO 2021 / 198262 pamphlet has a trapezoidal shape. Often, plastic material is used for the coupling element because it is easy to mold in the required shape, more specifically in a complex shape, in order to serve as a light guide. However, the thermal expansion coefficient and refractive index of plastic are different from those of glass, which results in light loss of the light emitted by the light source through the glazing, and furthermore, it also affects the stability of the lighting glazing. Another problem associated with plastic couplings is that the aging of the plastic material exceeds that of glass, which may lead to a decrease in brightness or color shift, and ultimately, it is necessary to change the plastic coupling element. Summary of the Invention Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a laminated lighting glazing, particularly a laminated glazing roof that is relatively easy to manufacture and has a good aesthetic appearance. The present invention also proposes a method for manufacturing such a laminated glazing. Means for Solving the Problems

[0006] According to the present invention, this object is achieved by an illuminated vehicle glazing having: (i) an outer glass pane, (ii) an inner glass pane acting as a light guide layer, (iii) a first and a second glass pane laminated together via at least a first plastic intermediate layer, (iv) light decoupling means provided between the first plastic intermediate layer and the inner glass pane, (v) a masking band provided along the periphery of the inner surface (P2) of the outer glass pane and / or the inner surface (P4) of the inner glass pane, and (vi) a light source provided on or in the vicinity of the masking band, the light source being arranged on the inner surface (P4) of the inner glass pane.

[0007] According to the present invention, at least one coupling element for coupling the light emitted from the light source (into the inner glass pane) is provided in the vicinity of the light source in a zone where there is no masking band and is substantially joined to the inner glass pane (on its inner surface (P4)), where the light source faces the side edge of the coupling element and the coupling element is made of glass.

[0008] Thus, according to the present invention, there is proposed a vehicle glazing in which the light emitted by the light source can be coupled into the light guide layer over a large area, in particular by using a coupling element arranged on the inner surface of the glazing.

[0009] According to the proposed invention, it is possible to optimally adapt the light guide layer to the requirements regarding its dimensions (large area) or its base area of the glazing. In addition to this, only light having a specific angle of incidence is coupled into the internal glass pane acting as a light guide layer. Preferably, in order to remain within total internal reflection (TIR) within the internal glass pane, the angle of incidence of the light is 14° or less (0° being the glass pane), and depending on the additional layer / coating on the glazing, the angle of incidence can increase up to 30° at most. Rays of light outside this range are not coupled and thus they do not propagate within the internal glass pane, the reason being that the light will not remain in TIR. As a result, the luminance, and furthermore the uniformity of the luminance, is improved on the surface of the internal glass pane. Accordingly, the coupling element provided on the inner surface (P4) of the internal glass pane guides the light emitted by the light source into the light guide layer at a defined angle, with the result that a relatively high coupling efficiency is achieved. The coupling efficiency should be understood as the efficiency of the light that is coupled into the glass sheet by TIR and can propagate therein, i.e., light that is coupled into the inner glass pane but cannot propagate in the TIR state is counted as a loss.

[0010] According to the invention, the coupling element can be arranged on the inner surface of the internal glass pane in the case where the glazing is a laminated glazing, or on the inner surface of the glazing in the case where the glazing is toughened safety glass and laminated safety glass.

[0011] According to the invention, the glazing is laminated safety glass. The glazing has an outer pane and an inner pane laminated together due to an intermediate layer, in particular a thermoplastic intermediate layer.

[0012] According to the invention, the internal glass pane acts as a light guide layer. As a result, the need for a light guide layer for illuminating the glazing is solved in that the internal glass pane can be used as a light guide layer.

[0013] As is generally used, a masking band, also referred to as a black band, which is generally made of enamel, is provided along the periphery of the inner surface (P2) of the outer glass pane and / or the inner surface (P4) of the inner glass pane.

[0014] According to the present invention, the light source is provided on the inner surface of the inner glass pane. The light source is preferably provided in the vicinity of the edge of the masking band. The light source is preferably not arranged on the black band.

[0015] According to the present invention, the coupling element can be directly attached to the inner surface of the inner glass pane. The coupling element is preferably coupled to the light source. Therefore, the coupling element is provided in the vicinity of the light source and is preferably in contact with it (either in direct contact or not in direct contact) so that the light coming out of the light source can be coupled to the coupling element.

[0016] In a particular embodiment, in the case of a laminated safety glass, a further light guide layer is applied to the inner glass pane, and the light from the light source can be coupled into this using coupling means.

[0017] One advantage of the present invention is that the coupling element can be easily arranged on the inner surface of the inner glass pane without incurring associated additional costs. In fact, the coupling element can be attached to the glazing after its assembly, thereby avoiding shape changes, bending, and optical distortion of the glazing. Furthermore, it is also possible to attach the coupling element before bending. Also, since the coupling element is made of a glass material as the glazing itself, it should be understood that it is more convenient to manufacture the glazing having the coupling element of the present invention. Accordingly, the inner glass can have the same dimensions as the outer glass pane. Also, the present invention has great potential for combinations with other options, such as a glazing that combines lighting and switchable functions (similar to PDLC) with solar cells that are easier to manufacture than standard glazing roofs.

[0018] Furthermore, the restrictions due to the placement or installation space are reduced because the coupling is provided on one inner surface of the glazing rather than in a hole or notch provided in the edge of the inner glass pane or in the inner glass pane for integration of the light source. Furthermore, the coupling element (as well as the light source) is arranged in a dry zone of the passenger vehicle that is protected from moisture or water.

[0019] According to one embodiment of the present invention, the inner glass pane is preferably made of a glass material.

[0020] The intermediate layer used for laminating the inner and outer glass panes is preferably formed of a material including PVB, EVA, and TPU. The intermediate layer can be clear or transparent or can be colored.

[0021] In a preferred embodiment of the present invention, the coupling element of the vehicle window according to the present invention is designed like a strip and is preferably arranged in the vicinity of the edge on the inner surface of the inner glass pane in an area without a masking band. The coupling element is coupled to a light source. Then, light is coupled into the inner glass pane due to the extension of the strip-like coupling element. In a special embodiment of the vehicle glazing according to the present invention, a plurality of coupling elements of the above type are provided, and these can be arranged in proximity to the edge on the edges on the opposite sides of the pane body configuration.

[0022] According to the present invention, the coupling element is made of a glass material. The shape or dimensions of the coupling element are designed so as to optimize the coupling angle of the light coupled into the inner glass pane acting as a light guide layer. The advantage of the glass coupling element lies in the fact that it can be easily manufactured from the glass pane. Therefore, the manufacture of the lighting glazing according to the present invention has a relatively low cost for manufacture but still has a sufficient coupling efficiency.

[0023] The thickness and width of the coupling element should be carefully selected to maximize the coupling efficiency of the light rays that can remain in TIR within the second glass pane.

[0024] The thickness should actually be kept as small as possible while recognizing that it is limited to be the size of the light source. In practice, a thickness of not more than twice the thickness of the second glass can be considered efficient.

[0025] The width will be optimized so as to allow a portion of the light to bounce back on the inner surface of the coupling element and then be coupled in TIR into the inner glass pane, allowing the maximum value of the light to propagate directly towards the inner glass pane acting as a light guide.

[0026] According to the present invention, the coupling element preferably has a cross-section with a flat shape. Therefore, the coupling element can be easily manufactured.

[0027] Therefore, the coupling element acts in the manner of an optical prism.

[0028] According to the present invention, the coupling element is made of glass. The refractive index of the coupling element is specifically adapted to the refractive index of the internal glass pane acting as the light guide layer, and preferably has a value of 1.40 to 1.65, particularly 1.48 to 1.59. In the specification, the term "refractive index" may be abbreviated by the symbol "nX" or "NX".

[0029] According to a preferred embodiment of the present invention, the composition of the coupling element is the same as or similar to the composition of the internal glass pane. In a preferred embodiment, the refractive index of the coupling element is equal to or greater than the refractive index of the internal glass pane.

[0030] To improve internal reflection, the coupling element can be provided with a reflective coating, which can contain a metal such as aluminum or silver and can be applied after a vapor deposition or sputtering process.

[0031] According to another embodiment of the present invention, the edge of the coupling element is ground with a polished surface finish to increase the transmission of visible light. Also, the edge can be ground into a convex, concave, or other shape to assist in focusing light at the center of the edge. In a preferred embodiment, at least the edge of the notch is ground to a flat profile (simple chamfering) and polished to facilitate the incidence of light from the light source into the internal glass pane. As a result, the edge has relatively high optical transparency with respect to the light from the light source.

[0032] The coupling element is preferably attached to the inner surface (P4) of the internal glass pane due to an adhesive layer.

[0033] The adhesive layer having a refractive index preferably of 1.405 to 1.657, more preferably of 1.48 to 1.567, can be formed from any optically suitable adhesive. More preferably, the refractive index of the adhesive layer is from 1.51 (refractive index of the glass pane) to 1.6 in order to minimize losses due to reflection. The adhesive layer has a refractive index greater than that of at least the intermediate layer used to laminate the outer and inner glass panes.

[0034] For example, the adhesive layer is made from a pressure-sensitive adhesive, an optically clear liquid adhesive (LOCA), ethylene vinyl acetate (EVA), polyvinyl butyral (PVB), thermoplastic polyurethane TPU (TPU), an epoxy adhesive, or an acrylic-based adhesive. More preferably, the adhesive layer is an optical glue. The adhesive layer has transparency with respect to the wavelengths used.

[0035] The selected material preferably has a refractive index that minimizes refraction of light at the interface and optimizes the coupling efficiency under ideal angular conditions.

[0036] The refractive index of the inner pane made of glass is specifically 1.510, while the refractive index of the coupling element and the adhesive by which the coupling element is connected to the inner pane can vary depending on the selected material. As a result, the coupling element has a refractive index that is equal to or greater than that of the inner glass sheet. The refractive index of the adhesive layer is equal to or greater than that of the coupling element.

[0037] According to one embodiment of the present invention, the coupling element preferably has a flat surface facing the light source in order to focus the light. Then, the light is injected into the coupling element through that flat surface.

[0038] According to another embodiment, the edge of the coupling element can be curved in order to optimize the direction of the light. The coupling element can have a curvature that fits the curvature of the glazing.

[0039] Also, the area / surface of the coupling element can also be provided with a reflective coating.

[0040] In an alternative embodiment of the vehicle window according to the invention, the light source is arranged directly on the side surface of the coupling element.

[0041] For example, a light source designed as a particularly high-performance LED module is an LED bar or LED strip having a number of LEDs, and these LEDs emit their light directly into the coupling element.

[0042] According to one embodiment of the invention, a plurality of light sources are provided along the periphery of the glazing. Furthermore, the light sources can be provided on one of the opposite sides of the glazing or on two sets of opposite sides.

[0043] In another embodiment, the light source is an optical fiber for transmitting light, a waveguide combined with an LED, or a laser diode.

[0044] According to one embodiment of the invention, in order to optimize the coupling of light on the coupling element, within the glazing, particularly within the roof, a tape, a mirror coating, or a reflective paint can be provided on the surface opposite to the incident side of the light. As a result, the light loss is reduced.

[0045] Furthermore, a cladding element or a cover can also be provided on the inner surface of the inner glass pane that conceals the coupling element and the light source.

[0046] The cover forming the housing can be joined to the glazing.

[0047] According to another embodiment, the light source and the coupling element can be encapsulated on the inner glass pane and / or the inner surface of the edge of the glazing. The encapsulation means can be an element made by injection molding on the first major surface of the first sheet and, if necessary, on the first major surface of the second sheet if the shape of the boundary line of the glazing unit is suitable for this purpose, or can be a preformed bead such as an adhesive or elastomer bead applied and fixed at the boundary line of the glazing unit.

[0048] The light source can be fixed on the side edge of the coupling element using a resin or an optical adhesive. Thus, the light source, specifically the LED and its associated electronic components fixed to the printed circuit board, are fixed on the inner surface of the inner glass pane and / or on the edge of the glazing by a polymeric material such as silicon, epoxy, polyurethane. Due to the optical resin, the beam shape from the light source can be adapted. Thus, when the light source is protected from moisture, an appropriate transparency level is maintained to allow proper light injection into the glass.

[0049] Also, due to the special configuration of the light source and the coupling element on the inner surface of the inner glass pane of the glazing, for example, the thermal stress applied to the light source formed from an LED is smaller than when laminated in the glazing. Furthermore, the light source is in a relatively poor contact state with the intermediate layer, resulting in a relatively poor chemical interaction (increase in the life of the light source) between the light source and the intermediate layer. In addition to this, the light source can be easily replaced so that no breakage of the composite between the pane and the light conducting layer occurs.

[0050] According to one embodiment of the present invention, the optical decoupling means can be provided between the intermediate layer used to laminate the inner glass pane with the outer glass pane and the inner glass pane. The optical decoupling means may be the textured inner surface of the inner glass pane. The textured surface of the inner glass pane can be obtained by texturing the inner surface (P3) of the inner glass pane. Also, the texturing can also be obtained by applying paint on the inner surface of the inner glass pane. Also, the texturing may be obtained by laser structuring of the surface, which acts as an optical decoupling means such that the light emission of the laterally coupled light is preferably provided through a main surface with a relatively low level. All these techniques of texturing are well known to those skilled in the art.

[0051] According to one embodiment of the present invention, the optical decoupling means may be an optical decoupling intermediate layer that can be laminated within the glazing. The optical decoupling layer has a surface structure, which acts as an optical decoupling means such that the light emission of the laterally coupled light is preferably provided through a main surface with a relatively low level. The structuring is provided, in this case, particularly on the inner surface of the layer facing towards the inner glass pane.

[0052] Also, the subject matter of the present invention is a vehicle roof having a vehicle glazing of the type described above.

[0053] The present invention also relates to the use of a parallelepiped-shaped coupling element for coupling the light emitted from a light source into an inner glass pane acting as an optical waveguide of a laminated glazing, where the light source faces the side edge of the coupling element, and the coupling element and the light source are arranged on the inner surface P4 of the inner glass pane. Another object of the present invention is to provide a coupling element having a simplified shape such that the manufacturing of the coupling element is facilitated in comparison with the complex-shaped coupling elements used in the prior art, regardless of the material of the coupling element.

[0054] In a preferred embodiment, the coupling element has a rectangular-like shape. Thus, a simple shape can be used to manufacture a laminated glazing for coupling light and having uniform illumination in the glazing area.

[0055] In a preferred embodiment, the coupling element is made of glass. Thus, the coupling element will have a refractive index close to that of the glass pane used to form the glazing. Further, the coupling element may be cut out from the mother pane used to form the glass pane forming the glazing, thereby simplifying the manufacturing process and thereby reducing costs while maintaining relatively good performance.

[0056] The invention also covers a method for manufacturing a laminated article as described in the invention. The method has the following steps: a. Providing an external glass pane having outer and inner surfaces, b. Providing an internal glass pane having outer and inner surfaces, c. Providing a light decoupling means between the external and internal glass panes, d. Laminating the external and internal glass panes with an intermediate layer, e. Applying a coupling element and a light source onto a part of the inner surface of the internal glass pane, provided that the coupling element is glass and has a parallelepiped-like shape.

[0057] The coupling element is the same as that described in this specification.

[0058] Further advantages and advantageous configurations of the subject matter of the invention can be found in this specification, the drawings, and the claims.

[0059] Embodiments of the glazing according to the invention, in particular for vehicle roofs of vehicle windows, are shown in schematic form in the drawings and will be explained in more detail hereinafter. [Brief description of the drawings]

[0060]

Figure 1

[0061]

Figure 2

[0062]

Figure 3

Figure 4

[0063] FIG. 1 shows a vehicle roof 10 of a motor vehicle, without showing details of the vehicle.

[0064] The vehicle roof 10 is in this example a fixed glazing panoramic roof divided into three areas (A, B, C) in which at least one light source 20 and a coupling element 30 are to be arranged. The roof 10 is intended to be fixed to the vehicle bodywork in an opening.

[0065] The glazing roof 10 is, for example, embodied as a laminated vehicle glazing. The glazing unit according to the invention is preferably mounted on the vehicle such that the inner glass pane is in contact with the passenger compartment of the vehicle and the outer glass pane is generally located closer to the exterior of the vehicle in direct contact with the atmosphere outside the vehicle.

[0066] In order to protect and conceal non-aesthetic elements such as adhesives fixed on the glazing, fixing means, etc., a masking band 25 is provided along the periphery of the glazing. The black band is well-known to those skilled in the art. Generally, the black band, which is typically enamel, can be provided around the inner surface P2 of the outer glass pane 11 and / or the outer surface P4 of the inner glass pane 12.

[0067] The inner glass pane 12 may be clear glass, or, more preferably, the inner glass pane 12 may be extra-clear glass.

[0068] This structure is shown in more detail in Figure 2.

[0069] In this particular embodiment, a decoupling layer 13 is provided between the outer and inner glass panes 11, 12, specifically configured to decouple the light coupled at the end side in the longitudinal direction through the layer. Further, the decoupling layer 13 has a surface structuring that acts as a decoupling means for light such that the light emission of the laterally coupled light is preferably generated through a main surface with a relatively low value, i.e., the decoupling layer 13 causes a portion of the light coupled in the inner glass pane 12 to be decoupled and emitted towards the passenger compartment, i.e., the inside of the vehicle, from the glass pane 12, thereby propagating in a TIR state for the purpose of providing an illuminated glazing. The structuring is provided, in this case, specifically on the inner surface of the layer 13 facing the inner glass pane 12.

[0070] The decoupling is based on the effect that the light is refracted or scattered on the structuring 13 and thus emitted at an angle that enables it to exit the surface of the layer 12. In the absence of the structuring, the coupled light typically impinges at a flat angle on the surface of the layer 12 where total internal reflection of the light occurs.

[0071] The structuring 13 on the surface of layer 12 is mechanically generated, for example, by imprinting the structure into the surface. Alternatively, instead of this, the structuring can also be generated by printing, especially using pad printing, such that the printed material represents a scattering structure. A further possibility for the structuring of the surface of layer 12 involves surface etching, according to which the surface is roughened to generate a scattering effect. Furthermore, the roughening or structuring can also be achieved by a blasting method, such as by sandblasting for example.

[0072] The outer glass pane 11 and the inner glass pane 12 are laminated together with the intermediate layer 14.

[0073] The thermoplastic intermediate layer 14 is provided between the inner surface (P2) of the outer glass pane 11 and the decoupling layer 13 in order to laminate the outer and inner glass panes. The intermediate layer 14 can have a plurality of functions. On the one hand, this can be used as a lamination layer that generates a permanent bond between pane 11 and glass pane 12. In addition to this, the intermediate layer 14 can also be implemented as a refractive layer, which in particular has a lower refractive index than the decoupling layer. Thus, the light incident on the interface between layer 13 and layer 14 remains within the decoupling layer 13 and does not pass into the inner pane 12 (nor into the outer pane 11). As a result, light absorption in pane 11 or light emission from the vehicle to the surroundings is avoided. The intermediate layer 14 is, in a preferred embodiment, gray or colored PVB. The thickness of the PVB can be standard, for example, as about 0.75 mm to 0.8 mm. However, the thickness can also be less than 0.75 mm. In another embodiment, several relatively thin intermediate layers 14 can be superimposed. The use of gray PVB has the advantage of absorbing the light of the structuring 13 in order to concentrate the light inside the glazing and / or ultimately reduce the double image generated by the structuring 13 on the outer glass pane. This is particularly useful when the glazing is provided with an IR-reflective coating or the like.

[0074] In addition to this, the intermediate layer 14 can also serve as a splinter protection layer or a splinter protection film. For example, the layer 14 is made of polyvinyl butyral (PVB) for this purpose.

[0075] The intermediate layer 14 is preferably provided such that it acts not only as a lamination layer, but also as a refractive layer and furthermore simultaneously as a splinter protection film. Alternatively, instead of this, the three functions can also be realized by the corresponding layer structures of a plurality of films. The intermediate layer extends on the surfaces of the glass panes 11, 12. Accordingly, the laminated glazing includes at least one light source provided with surface illumination having improved uniformity. Another object of at least some embodiments is to provide such a surface illumination panel that provides relatively uniformly diffused surface illumination.

[0076] According to one embodiment of the present invention, at least one coupling element 30 is fixed on the inner surface (P4) of the inner glass pane 12. Preferably, a plurality of coupling elements 30 are provided along the lateral edges of the glass pane 12. The coupling element 30 is made of glass, i.e., a glass material similar to the glass used in vehicle glazing. Advantageously, the coupling element has the same or a refractive index close to that of the inner glass pane 12. The refractive index may be greater than the refractive index of the inner glass pane 12.

[0077] Preferably, the refractive index of the coupling element is between 1.48 and 1.59.

[0078] According to one embodiment of the present invention, the coupling element 30 preferably has a flat shape. However, the coupling element can be curved to fit the curvature of the roof. Preferably, the coupling element has a rectangular shape. The width, length, and height should be adapted according to the type of light source and glass used to make the coupling element. The dimensions of the coupling element 30 should be adapted according to the specifications of the passenger vehicle manufacturer and the type of light source used to achieve uniform peripheral lighting on the surface of the glazing, more specifically on the surface of the glazing roof.

[0079] Preferably, the height is the same as or similar to the height of the inner glass pane 12 acting as a light guide, and more preferably less than the thickness of the inner pane 12. The thickness and height are used interchangeably in this context.

[0080] Preferably, the coupling element 30 is provided along at least a part of the lateral edge of the glazing 10 as shown in FIG. 1. The coupling element and the associated light source may be provided on the right or left side of the glazing to fit the required peripheral lighting, but are not limited thereto. It should be understood that the light source may be provided on the front or rear side of the glazing 10.

[0081] Preferably, the glass composition of the coupling element 30 is similar to the composition of the glass composition of the inner glass pane 12. In a preferred embodiment, the coupling element is made of extra-clear glass in order to have relatively little absorption of light and, as a result, relatively little loss. The coupling element can be made of glass having weak absorption. This can potentially be more absorbent than the inner glass pane because the path of light in the coupling element is very short compared to the path in the inner glass.

[0082] According to the present invention, the coupling element 30 is arranged in the vicinity of the masking band 25 within a zone where there is no masking band in order to minimize the absorption loss of the masking band. The term "vicinity" should be understood as being in proximity to the masking band 25, and the distance between the two is less than 20 cm, and more preferably less than 10 cm in this context.

[0083] According to an embodiment of the present invention, the light source 20 is provided such that light is preferably emitted perpendicular to the flat edge 310 of the glass coupling element 30. The edge of the coupling element can be curved. As a result, the light emitted by the light source 20, once activated, is coupled into the coupling element 30.

[0084] Preferably, the light source 20 and the coupling element 30 are arranged in the vicinity of the masking band within a zone where there is no masking band. In one embodiment, only the coupling element is present within the zone where there is no masking band. As described above, the term "vicinity" should be understood in the same way as in the above context in this embodiment.

[0085] The light source 20 is preferably one or more modules each including a plurality of light-emitting diodes fixed to a printed circuit board and related electronic components, and in this case, the module is positioned such that the emission surface of the LED faces towards the edge of the first glass coupling element 30. The light source 20 may be an upper-emitting LED or a side-emitting LED depending on the intended application, because the coupling element 30 allows both configurations.

[0086] The light source can be fixed on the edge of the glazing using a resin or an optical adhesive. Thus, the light source and in particular the LEDs fixed to the printed circuit board and their associated electronic components are fixed on the glazing edge by a polymeric material such as silicon, epoxy, polyurethane. Due to the optical resin, the beam shape from the light source can be adapted. Thus, while the light source is protected from moisture, the correct transmission level is maintained to allow correct light injection into the glass.

[0087] The light source 20 can be encapsulated in a housing in order to fix the light source on the glazing and furthermore to protect it from external influences. The light source 20 can be encapsulated on the edge of the glazing and / or on the edge of the coupling element. The encapsulation means may be an element prepared by injection molding, or a pre-formed bead such as an adhesive or elastomer bead applied and fixed at the boundary of the glazing unit on the first main surface of the first sheet and, if necessary, on the first main surface of the second sheet where the shape of the boundary of the glazing unit is suitable for this purpose.

[0088] The LED may be a side-emitting LED or an upward-emitting LED. The side-emitting LED forms a preferred embodiment. In the case of a side LED, the LED can be arranged relatively easily perpendicular to the plane of the coupling element 30 for good coupling inside the coupling element 30 and the inner glass pane 12.

[0089] In another embodiment, the light source 20 may be a waveguide coupled to an LED or a diode laser or an optical fiber.

[0090] In a particular embodiment, the light source 20, in particular the LED module, is arranged along at least a part of the lateral edge 310 of the coupling element 30. The LED module is then fixed on the glazing 10, for example, by encapsulation means.

[0091] According to an embodiment of the present invention, an optical guide can be provided between the coupling element 30 and the light source 20. The optical guide may be a rod or a cord, and includes, for example, a plastic sheet, a PMMA material, and / or a polycarbonate material, an optical fiber (or a bundle of fibers), or a silicone material. Providing an optical guide between the coupling element 30 and the light source 20 may be necessary in some cases because the size of the electronic circuit may not allow for a direct connection from the light source 20 to the coupling element 30.

[0092] In a preferred embodiment of the present invention, the light source having the electronic circuit and the optical guide in the above-described embodiment are integrated within a casing / housing that protects the elements. This preferred embodiment enables the casing to be fixed / attached onto a glazing having a light source, and thus, a coupling element already attached to the second glass pane. Further, it enables the alignment of the light source having the coupling element to be a simple mounting / clipping process. Further, this also promotes the serviceability of the lighting glazing in case of malfunction or any problem, and the light source can be replaced without any hurdles.

[0093] The coupling element 30 is fixed on the inner surface (P4) of the inner glass pane 12. Preferably, the coupling element 30 is fixed using an adhesive layer 22.

[0094] The adhesive layer 22 has a refractive index within the range of the refractive index of the coupling element 30 or between the refractive index of the coupling element 30 and the refractive index of the inner glass pane 12 acting as an optical guide. Preferably, the refractive index is between 1.48 and 1.56. As the material for the adhesive layer 22, a pressure-sensitive adhesive, an optically clear liquid adhesive, EVA, PVB, TPU, an epoxy adhesive, or an acrylic adhesive can be used.

[0095] Through internal reflection at the boundary surface of the coupling element 30, light is coupled into the internal glass pane 12 acting as a light guide layer via the adhesive layer 22, and the light can propagate therethrough via internal reflection at the boundary surface.

[0096] FIG. 2 is a cross-sectional view for explaining the optical characteristics of the laminated glass according to the present embodiment. The configuration of the glazing 10 is similar to the exemplary configuration shown in FIG. 1 and FIG. 2.

[0097] The light A irradiated from the light source 20 to the light receiving surface 310 of the coupling element 30 (optical element) propagates inside the coupling element 30 as shown in FIGS. 3 and 4. At this point, the refractive index of air is n1, the refractive index of the coupling element 30 is n2, and when the light A enters the optical element 30 at the incident angle θ1, the incident light is refracted at an angle of θ1’’ (n1*sin(θ1) = n2*sin(θ1’’)), and the refracted light propagates at the incident angle θ2 toward the adhesive layer 22. Further, the light propagates in the adhesive layer 22 such as an optical adhesive (bonding element) either directly or after bouncing on the surface 320. In this case, the surface 320 is the surface of the coupling element 30 that is not exposed (not facing) to the adhesive layer 22 or the light source 20. At this point, the refractive index of the bonding element or the adhesive layer 22 is n3, and when the light enters the bonding element at the incident angle θ2, the incident light is refracted at an angle of θ2’’ (n2*sin(θ2) = n3*sin(θ2’’)), and the refracted light propagates at the incident angle θ3 toward the internal glass pane 12. Further, the light propagates into the second glass 12 through the surface P4. At this point, the refractive index of the second glass is n4, and when the light enters the second glass at the incident angle θ3, the incident light is refracted at an angle of θ3’’ (n3*sin(θ3) = n4*sin(θ3’’)), and the refracted light propagates at the incident angle θ4 toward the intermediate layer 14. It can be easily seen that the angle θ2 is equal to 90 - θ1’’, the angle θ3 is equal to θ2’’, and the angle θ4 is equal to θ3’’.

[0098] In order to stay in TIR (total internal reflection) inside the second glass pane 12, the incident angle θ4 of light must be equal to or greater than the critical angle θ4 C = arcsin(n5 / n4), where n5 is the refractive index of the intermediate layer 14. The conditions for total internal reflection are very simple and are given here for illustrative purposes and are schematically shown in FIG. 4. The optical decoupling means 13 does not necessarily have its own refractive index. For example, in the case where the optical decoupling means 13 is the surface roughness on the P3 surface of the second glass pane 12, it is clear that the optical decoupling means 13 may have the refractive index in the case where it is an actual physical layer. In that case, it should be understood that n5 is the refractive index of the optical decoupling means 13. The present invention aims to increase the coupling efficiency in a simplified and cost-effective manner by the coupling element 30. Therefore, the present invention is not interested in the manner in which the optical decoupling means 13 is constructed, because a coupling element made of glass naturally satisfies the conditions for total internal reflection in the second glass pane 12.

[0099] The refractive indices of the coupling element and the adhesive layer (bonding element) should be carefully selected to maximize the coupling efficiency. In the case of an incorrect selection, the worst scenario is that the light will not propagate in TIR inside the second glass pane 12.

[0100] Preferably, n2, n3, and n4 should have the same refractive index, and this condition can be easily satisfied by the coupling element 30 of the present invention, because in a preferred embodiment, the coupling element 30 is made from the same mother pane as the second glass pane 12.

[0101] The thickness and width of the coupling element 30 should be carefully selected to maximize the coupling efficiency of the light rays that can stay in TIR within the second glass pane 12. That is, an increase in the width of the coupling element 30 at a specific level results in relatively more light from the light source 20 being coupled into the second glass pane 12.

[0102] The thickness should be kept as small as possible while recognizing that it is actually limited to be the size of the light source 20. Preferably, a thickness of no more than twice the thickness of the second glass pane 12 can be considered to have good efficiency.

[0103] The width will be optimized to allow maximum light to propagate directly towards the second glass pane 12 and to allow a portion of the light to bounce off the surface 320 of the coupling element 30 and then be coupled in TIR within the second glass pane 12.

[0104] In the above-described embodiment, a low-E coating (low emissivity layer) as a reflective heat radiation coating can be provided on the surface (P4) of the glazing surface, particularly on the glass roof facing towards the passenger compartment. Thus, a glazing roof provided with a heat radiation reflective coating, particularly a low-E coating, provides the best possible compromise between the outside vision through the roof and good thermal properties due to its long-wavelength infrared (IR) energy reflection characteristics.

[0105] Also, according to an embodiment of the present invention, the heat-radiation reflecting coating can be referred to as a coating having a low emissivity, an emissivity-reducing coating, a low-E coating, or a low-E layer. Its role is to reflect heat radiation, i.e., IR radiation having a wavelength longer than the IR component of solar radiation, in particular. At a low outside temperature, the low-E coating reflects heat back inside and reduces internal cooling. At a high outside temperature, the low-E coating prevents the absorbed heat radiation of the heated glazing from being re-emitted inward and reduces internal heating. On the inner side surface of the inner pane, the coating according to the present invention particularly effectively reduces the emission of heat radiation from the pane to the inside in summer and reduces the transmission of heat to the external environment in winter.

[0106] At this position, it has been selected to place the coating at position 4 despite the fact that the layer is not protected from degradation, particularly mechanical degradation. A low-E layer having sufficient mechanical and chemical resistance can be selected.

[0107] Advantageously, for good mechanical resistance, the coating is a "hard" layer such as one produced by PECVD, CVD, or pyrolysis techniques. However, the low-E system can also be manufactured using vacuum cathodic sputtering techniques if the resulting system is composed of layers having sufficient resistance.

[0108] According to the present invention, it is preferable to use a low-emissivity coating system having an emissivity of less than 0.3, preferably less than 0.2, and particularly preferably less than 0.1.

[0109] The most common pyrolytic low-E (low emissivity) systems have a layer of doped tin oxide deposited on a first layer that serves as a neutral color in reflection. The layer in contact with the glass is usually a layer of silica or silicon oxycarbide optionally modified by additives. In comparison to the layers of the system deposited by cathodic sputtering, the tin oxide layer is relatively thick, i.e., more than 200 nm in thickness, and in certain cases more than 450 nm. These thick layers have sufficient resistance to withstand exposure to mechanical and / or chemical erosion.

[0110] According to one embodiment, a filtering infrared radiation coating can be provided on the inner surface (P2) of the outer glass pane. The coating can be provided on the inner surface (P3) of the inner glass pane. The coating has one or more metal layers basically based on silver, combined on the one hand with a dielectric layer that protects the metal layer. The infrared reflective coating can be present within the glazing, usually in a state facing the intermediate PVB layer, such that the coating is positioned within P2 or P3. The infrared reflective coating preferably has n infrared reflective (IR) layers and n + 1 dielectric layers such that each IR layer is surrounded by two dielectric layers, where n ≧ 1. The IR layers can be made from silver, gold, palladium, platinum, or alloys thereof, while the dielectric layers can usually have oxides, nitrides, oxynitrides, or oxycarbides of Zn, Sn, Ti, Zr, Si, In, Al, Bi, Ta, Hf, Mg, Nb, Y, Ga, Sb, Mg, Cu, Ni, Cr, Fe, V, B, or mixtures thereof. The role of the IR reflective coating is to reflect the infrared portion of solar radiation. A normal infrared reflective coating can be provided by physical vapor deposition to form a coating having a thickness in the range of 10 - 250 nm.

[0111] According to one embodiment, for the purpose of thermal protection, for changing the light transmittance of the glazing, for adjusting coloring and privacy, for diffusing reflection, solutions such as electrically powered functional films are provided between the outer glass pane whose conditions of use have already been proposed and at least one thermoplastic intermediate layer. Thus, the glazing can have a functional film such as an electrochromic means obtained by changing the state of colored ions in the composition contained within these glazings. Also, this is a problem of glazing having a layer of particles that are ordered or not in suspension depending on the application of a voltage, such as a system called a suspended particle device (SPD), or, in a preferred embodiment, a polymer dispersed liquid crystal (PDLC) film or guest-host liquid crystal (GHLC) composed of a polymer containing a liquid crystal sensitive to the application of a voltage. These functional films allow the light level in the passenger compartment to be changed, and their function is also to change the anti-glare effect and the level of privacy. Another role of these films is to protect the interior of the passenger compartment from heat. Specifically, these functional films are films that are switchable between a dark state and a semi-transparent or possibly transparent state.

[0112] The glass panes used to form the laminated glazing unit may have the same composition and possibly the same thickness, which can relatively easily allow them to be preformed, for example, in a state where two sheets are bent simultaneously. Most often, the glass sheets have different compositions and / or thicknesses, and in this case, they can be formed separately.

[0113] The possible presence of a colored intermediate layer participates in the absorption of light. These uses can be envisioned as partial substitutes for the contribution of the glass sheet to establishing at least certain colors. This situation can occur, for example, when integrating a photovoltaic element within a glazing unit and at least the outer glass sheet is a glass with poor absorptive power or, in some cases, an extra-clear glass sheet. However, the outer sheet may also be an absorbing glass sheet, and there is no need for a colored intermediate layer. Thus, according to one embodiment of the present invention, an electrically powered light source or a functional film can be powered by a photovoltaic cell. Also, the energy generated by the photovoltaic cell can be used to power some other elements of the vehicle.

[0114] Also, the inner glass pane facing towards the passenger compartment can also be manufactured from clear glass and more preferably extra-clear glass. This is most often absorptive and contributes to an overall reduction in energy transmission. When its transmission is limited, this allows non-transparent elements present within the glazing unit to be at least partially concealed from the passenger's field of view. The inner glass pane can have a structuring of its outer surface (P3). For example, the structuring is mechanically generated, for example, by imprinting a structure within the surface. Alternatively, instead of this, the structuring can also be achieved by printing, in particular using pad printing, such that the printed material represents a scattering structure. Further possibilities for structuring the surface of the layer are composed of etching the surface, according to which the surface is roughened to generate a scattering effect. Furthermore, the roughening or structuring can also be achieved by a blasting method, such as by sandblasting.

[0115] The present invention provides a simplified and cost - effective solution to the bonding problem for lighting vehicle glazing by providing a bonding element made of a glass material and preferably the same material as the second glass pane. According to the present invention, the manufacture of such lighting glazing is simplified without sacrificing performance, i.e., without sacrificing the bonding efficiency. In addition to this, the manufacturing time is dramatically reduced because, in comparison with the wedge - shaped bonding prism known in the art, the bonding element does not require the generation of an extra process, because the bonding element of the present invention is a flat glass that is shaped in the normal way.

[0116] Combinations of the described embodiments are included in the present invention.

[0117] For the avoidance of doubt, the present invention is applicable for all means of transport such as automobiles, vans, lorries, motorcycles, buses, trams, trains, aircraft, helicopters, and the like. According to one embodiment of the present invention, the glazing may be a part of an automotive glazing roof, side light, back light, or front glass. Also, the glazing may be an external applique.

Explanation of Signs

[0118] 10 Vehicle roof 11 External glass pane 12 Internal glass pane 13 Optical decoupling layer 14 Intermediate layer 20 Light source 30 Bonding element 310 Side edge of the bonding element 320 Surface of the bonding element 22 Adhesive layer 25 Masking band

Claims

1. - External glass pane (11) having an outer surface (P1) and an inner surface (P2), - An internal glass pane (12) having an outer surface (P3) and an inner surface (P4) that act as a light guide layer, wherein the outer and internal glass panes (11, 12) are laminated together via at least a first plastic intermediate layer (14). - Photo-decoupling means (13) provided between the first plastic intermediate layer (14) and the internal glass pane (12), - A masking band (25) provided around the inner surface (P2) of the outer glass pane (11) and / or the inner surface (P4) of the inner glass pane (12), - A light source (20) provided on or near the masking band (25) and positioned on the inner surface (P4) of the inner glass pane (12), - At least one coupling element (30) is provided near the light source (20) in a zone where there is no masking band (25) and is substantially connected to the internal glass pane (12) on its inner surface (P4), wherein the light source (20) is facing the side edge (310) of the coupling element (30), In a lighting vehicle glazing (10) having, The aforementioned coupling element (30) is made of a glass material, and the lighting vehicle glazing (10) is characterized in that it is made of a glass material.

2. The lighting vehicle glazing (10) according to claim 1, characterized in that the coupling element (30) has a parallelepiped shape.

3. The lighting vehicle glazing (10) according to claim 1 or 2, characterized in that the connecting element (30) has a rectangular shape.

4. The lighting vehicle glazing (10) according to claim 1 or 2, characterized in that the coupling element (30) has a refractive index greater than or equal to that of the internal glass pane (12).

5. The lighting vehicle glazing (10) according to claim 1 or 2, characterized in that the adhesive layer (22) has a refractive index of 1.40 to 1.65, particularly 1.48 to 1.

56.

6. The lighting vehicle glazing (10) according to claim 1 or 2, characterized in that the connecting element (30) is attached to the inner surface (P4) of the inner glass pane via an adhesive layer (22).

7. The illuminated vehicle glazing (10) according to claim 1 or 2, characterized in that the light source (20) is preferably an LED strip.

8. The lighting vehicle glazing (10) according to claim 1 or 2, characterized in that the coupling element (30) has a glass composition similar to the glass composition of the internal glass pane (12).

9. The lighting vehicle glazing (10) according to claim 1 or 2, characterized in that the photo-coupler release means (13) is a photoconductive plastic intermediate layer.

10. The lighting vehicle glazing (10) according to claim 1 or 2, characterized in that the light-decoupling means (13) is the textured surface (P3) of the internal glass pane.

11. The lighting vehicle glazing (10) according to claim 1 or 2, characterized in that the glazing (10) is a glazing roof.

12. The use of a parallelepiped coupling element (30) for coupling light emitted from a light source (20) into an internal glass pane (12) that acts as a light guide for a laminate-type glazing (10), wherein the light source (20) is facing the side edge (310) of the coupling element (30), and the coupling element (30) and the light source (20) are positioned on the inner surface P4 of the internal glass pane (12).

13. The use of the connecting element (30) according to claim 12, characterized in that the connecting element has a rectangular shape.

14. The use of the bonding element (30) according to claim 12 or 13, characterized in that the bonding element is made of glass.

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