Illuminated vehicle glazing

Abstract

The present invention relates to an illuminated vehicle glazing comprising: (i) an outer glazing panel (11); (ii) an inner glass panel (12) acting as a light guide layer; (iii) a first glass panel and a second glass panel (11, 12), the first glass panel and the second glass panel being laminated together via at least a first plastic interlayer (14); (iv) a light decoupling device (13) arranged between the first plastic interlayer and the inner glass panel (12); (v) a masking strip disposed along the periphery of the inner surface (P2) of the outer glass panel and / or the inner surface (P4) of the inner glass panel; (vi) a light source (20) disposed on or near the masking tape, the light source being placed on the inner surface (P4) of the inner glass panel (12). According to the invention, at least one coupling element (30), which couples the light emitted by the light source (20) into the inner glazing panel (11), is arranged in the vicinity of the light source in the region without the shielding strip and is substantially bonded to the inner surface (P4) of the inner glazing panel (11), the light source (30) facing a side edge (310) of the coupling element.

Description

Technical Field

[0001] The present invention relates to an illuminated glazing unit for a vehicle, in particular to an illuminated glazing forming part of a roof of a motor vehicle. Such windows are known from practice and can be used in particular in the field of vehicle roofs. Background Art

[0002] It is known from the prior art that lighting vehicle glazings have a glass panel that acts as a light-guiding layer. It is also known that the roof of the glazing is provided with a light source that is coupled to the light-guiding layer. For the safety of the vehicle passengers, the glazing is a laminated glazing provided with an outer glass panel and an inner glass panel. It is known that the coupling element is arranged on the edge of the inner glass panel that acts as the light-guiding layer. Therefore, the inner glass panel is usually smaller than the outer glass panel in order to have enough space to fix the coupling element on the edge of the inner glass panel. Therefore, the light emitted by the light source can be coupled through the edge of the light-guiding layer.

[0003] Also known from EP 3463869 is a glazing having holes in which the light sources are arranged, making the glazing difficult to produce.

[0004] It is also known from WO 2021198262 to use a plastic coupling on the inner face of the roof. The coupling element described in WO'262 has a trapezoidal shape. Plastic material is often used for coupling elements because it is easy to form into the desired shape and more specifically into complex shapes in order to act as a light guide. However, the thermal expansion coefficient and refractive index of plastic are different from those of glass, which leads to losses of light emitted by the light source through the embedded glass and also affects the stability of the lighting embedded glass. Another problem with plastic couplings is that the degree of aging of the plastic material exceeds that of the glass, which can lead to a reduction in brightness or color shift, and ultimately the plastic coupling element needs to be replaced. Summary of the invention

[0005] The object of the present invention is to provide a lighting laminated glazing, and more particularly to provide a laminated glazing vehicle roof which is easier to produce and has good aesthetics. The present invention also proposes a method for producing such laminated glazing.

[0006] According to the present invention, the object is achieved by a lighting vehicle glazing, which comprises: (i) an outer glass panel; (ii) an inner glass panel acting as a light-guiding layer; (iii) a first glass panel and a second glass panel, the first glass panel and the second glass panel being laminated together via at least a first plastic interlayer; (iv) an optical decoupling device arranged between the first plastic interlayer and the inner glass panel; (v) a shielding strip arranged along the periphery of the inner surface (P2) of the outer glass panel and / or the inner surface (P4) of the inner glass panel; (vi) a light source arranged on or near the shielding strip, the light source being placed on the inner surface (P4) of the inner glass panel.

[0007] According to the present invention, at least one coupling element is arranged near the light source, in the area without the shielding band, and is substantially bonded to the inner glass panel (on the inner surface (P4) of the inner glass panel), and the at least one coupling element couples the light emitted by the light source into the inner glass panel, the light source faces the side edge of the coupling element, and the coupling element is made of glass.

[0008] According to the invention, a vehicle glazing is therefore proposed in which light emitted by a light source can be coupled into a light-conducting layer over a large area, in particular by means of coupling elements arranged on the inner surface of the glazing.

[0009] According to the proposed invention, this makes it possible to optimally adapt the light-guiding layer to the requirements in terms of the size of the glazing in which it is mounted (large area) or the area of ​​its base. In addition, only light with certain angles of incidence is coupled into the inner glass pane acting as a light-guiding layer. Preferably, in order to be retained in the inner glass pane by total internal reflection (TIR), the angle of incidence of the light is equal to or lower than 14° (0° is the glass plane), and depending on the layers / coatings added to the mounted glass, the angle of incidence can be as much as 30°. Light rays outside this range are not coupled in, so they do not propagate in the inner glass pane, because the light will not be retained by TIR. This improves the brightness on the surface of the inner glass pane and also the brightness uniformity. Therefore, the coupling element arranged on the inner face (P4) of the inner glass pane guides the light emitted by the light source into the light-guiding layer at a defined angle, as a result of which a higher coupling-in efficiency is achieved, the coupling efficiency being understood as the efficiency of the light coupled into the glass sheet by TIR and able to propagate in the glass sheet, i.e. the light coupled into the inner glass panel but not able to propagate under TIR conditions is regarded as a loss.

[0010] According to the invention, the coupling element can be arranged on the inner face of the inner glass pane when the glazing is laminated glazing, or on the inner face of the glazing when the glazing is tempered safety glass and laminated safety glass.

[0011] According to the invention, the glazing is a laminated safety glass.The glazing comprises an outer pane and an inner pane which are laminated together by an interlayer, and more particularly by a thermoplastic interlayer.

[0012] According to the invention, the inner glass pane acts as a light guiding layer.Thus, the need for a light guiding layer to illuminate the glazing is then solved by being able to use the inner glass pane as a light guiding layer.

[0013] As is commonly used, a masking band (also called black band), usually made of enamel, is provided along the periphery of the inner face ( P2 ) of the outer glass pane and / or the periphery of the inner face ( P4 ) of the inner glass pane.

[0014] According to the invention, a light source is provided on the inner face of the inner glass pane. The light source is preferably arranged near the edge of the masking strip. The light source is preferably not arranged on the black strip.

[0015] According to the invention, the coupling element can be directly attached to the inner face of the inner glass pane. The coupling element is preferably coupled to the light source. Therefore, the coupling element is arranged near the light source and is preferably in contact with the light source (directly or not) so as to be able to couple the light emitted by the light source to the coupling element.

[0016] In a particular embodiment, in the case of laminated safety glass, an additional light-guiding layer is applied to the inner glass pane, into which light from the light source can be coupled by means of a coupling element.

[0017] One of the advantages of the present invention is that the coupling element can be easily arranged on the inner face of the inner glass panel without the associated additional costs. In fact, the coupling element can be attached to the glazing after its assembly, thereby avoiding any changes in the shape, bending, optical deformation of the glazing. In addition, the coupling element can also be attached before bending. It should be understood that since the coupling element is also made of glass material like the glazing itself, it is more convenient to produce glazing with the coupling element of the present invention. The inner glass can therefore have the same dimensions as the outer glass panel. Moreover, the present invention allows greater potential for combination with other options, such as glazing combined with lighting and switchable functions (such as PDLC), where photovoltaic cells are easier to produce than standard glazed roofs.

[0018] Furthermore, since the coupling element is arranged on an inner face of the glazing instead of in the edge of the inner glass pane or in a hole or recess in the inner glass pane for integrating the light source, restrictions due to location or installation space are reduced. Furthermore, the coupling element (and the light source) are placed in a dry area of ​​the vehicle where they are protected from moisture or water.

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

[0020] The interlayer used to laminate the inner glass pane and the outer glass pane is preferably formed of a material including PVB, EVA and / or TPU. The interlayer may be clear or transparent or tinted.

[0021] In a preferred embodiment of the invention, the coupling element of the vehicle window according to the invention is designed like a strip and is preferably arranged near the edge on the inner face of the inner glass pane, in an area without a masking strip. The coupling element is coupled to the light source. Then, due to the extension of the strip-shaped coupling element, the light is coupled into the inner glass pane. In a special embodiment of the vehicle glazing according to the invention, a plurality of coupling elements of the above-described type are provided, which coupling elements can be arranged close to the edge on the opposite edge of the panel body arrangement.

[0022] According to the present invention, the coupling element is made of glass material. The shape or size of the coupling element is designed to optimize the coupling angle of light coupled to the inner glass panel acting as a light guide layer. The advantage of the glass coupling element is that it is easy to produce from glass panels. Therefore, the production cost of the lighting glazing according to the present invention is low and still has a fairly sufficient coupling efficiency.

[0023] The thickness and width of the coupling element should be carefully selected to maximize the coupling efficiency of light that will be retained in the second glass pane by TIR.

[0024] It is known that in practice the thickness is limited by the size of the light source and therefore the thickness should be kept as small as possible. In practice, a thickness equal to or less than twice the thickness of the second glass can be considered effective.

[0025] The width is optimized to allow the maximum amount of light to propagate directly towards the inner glass pane acting as a light guide, and to allow a portion of the light to be reflected on the inner surface of the coupling element and then coupled into the inner glass pane by TIR.

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

[0027] The coupling element thus acts in the manner of an optical prism.

[0028] According to the invention, the coupling element is made of glass. The refractive index of the coupling element is adapted in particular to the refractive index of the inner glass pane acting as light-guiding layer and preferably has a value between 1.40 and 1.65, in particular between 1.48 and 1.59. In this specification, the term "refractive index" may be abbreviated to the symbols "nX" or "NX".

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

[0030] To improve internal reflections, the coupling element may be provided with a reflective coating, which may comprise a metal such as aluminum or silver and may 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 to have a polished surface finish to increase visible light transmittance. The edge may also be ground to a convex, concave or other profile to help focus light inside the edge. In a preferred embodiment, at least the edge of the notch is ground to a flat profile (simple chamfer) and polished to facilitate light from the light source entering the inner glass panel. Thus, the edge is more optically transparent to light from the light source.

[0032] The coupling element is attached to the inner face (P4) of the inner glass pane, preferably thanks to an adhesive layer.

[0033] The refractive index of the adhesive layer is preferably between 1.405 and 1.657, more preferably between 1.48 and 1.567, and can be formed of any optically suitable adhesive. More preferably, the refractive index of the adhesive layer is comprised between 1.51 (refractive index of the glass panel) and 1.6, so as to minimize reflection losses. The refractive index of the adhesive layer is at least higher than the refractive index of the interlayer used to laminate the outer glass panel and the inner glass panel.

[0034] For example, the adhesive layer is made of 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 is transparent to the wavelength used.

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

[0036] The refractive index of the inner pane made of glass is in particular 1.510, whereas the refractive index of the coupling element and the adhesive by means of which the coupling element is connected to the inner pane can vary depending on the material chosen. The refractive index of the coupling element is then equal to or higher than the refractive index of the inner glass pane. The refractive index of the adhesive layer is equal to or higher than the refractive index of the coupling element.

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

[0038] According to another embodiment, the edges of the coupling element may be curved to optimize the direction of the light.The coupling element may have a curvature that matches the curvature of the glazing.

[0039] Areas / surfaces of the coupling element may 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 a side surface of the coupling element.

[0041] For example, light sources which are designed specifically as high-performance LED modules are LED bars or LED strips having a large number of LEDs which emit their light directly into the coupling element.

[0042] According to an embodiment of the present invention, a plurality of light sources are arranged along the periphery of the inlaid glass. Further, the light sources can be arranged on one side or two groups of opposite sides of the inlaid glass.

[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, on the coupling element, a tape, a mirror coating or a reflective paint may be provided on the surface opposite to the entrance of the light, in order to optimize the coupling of the light in the glazing and more particularly in the roof, thus reducing light losses.

[0045] Furthermore, a cladding element or a cover may be arranged on the inner face of the inner glass pane which conceals the coupling element and the light source.

[0046] The cover forming the housing may be bonded to the glazing.

[0047] According to another embodiment, the light source and the coupling element may be encapsulated on the inner face of the inner glass pane and / or on the edge of the glazing. The encapsulation means may be an element produced by injection molding or may be a preformed bead (e.g. an adhesive bead or an elastomer bead) which is applied and fixed at the border of the glazing unit, on the first main face of the first sheet and, if necessary, also on the first main face of the second sheet if the geometry of the border of the glazing unit is suitable.

[0048] The light source can be fixed to the side edge of the coupling element by means of resin or optical glue. Thus, the light source (especially LED) fixed to the printed circuit board and its associated electronic components are fixed to the inner face of the inner glass panel and / or to the edge of the embedded glass with a polymer material (such as silicon, epoxy resin, polyurethane). Due to the optical resin, the beam shape of the light source can be adjusted. Thus, the light source is protected from moisture while maintaining an appropriate level of transparency to allow appropriate light to enter the glass.

[0049] Due to the special arrangement of the light source and the coupling element on the inner surface of the inner glass pane of the glazing, the light source, for example formed by an LED, is also subject to less thermal stress than when laminated into the glazing. In addition, the contact of the light source with the interlayer is reduced, so that the chemical interaction between the light source and the interlayer is reduced (the service life of the light source is increased). In addition, the light source can be easily replaced without the composite between the pane and the light-conducting layer being damaged.

[0050] According to an embodiment of the invention, a light decoupling device may be provided between the interlayer (which is used to laminate the inner glass panel with the outer glass panel) and the inner glass panel. The light decoupling device may be a textured inner surface of the inner glass panel. The textured surface of the inner glass panel may be obtained by texturing the inner surface (P3) of the inner glass panel. The texturing may also be obtained by applying a coating to the inner surface of the inner glass panel. Furthermore, the texturing may also be obtained by laser structuring of the surface, which serves as a light decoupling device, so that a light emission of the laterally coupled light is preferably generated via the lower main surface. All those texturing techniques are well known to a person skilled in the art.

[0051] According to an embodiment of the invention, the light decoupling device can be a light decoupling interlayer which can be laminated into the glazing. The light decoupling layer has a surface structure which serves as a light decoupling device so that a light emission of the laterally coupled light occurs, preferably via the lower main surface. In this case, the structure is particularly arranged on the inner face of the layer facing the inner glass pane.

[0052] The subject matter of the invention is also a vehicle roof comprising a vehicle glazing of the type described above.

[0053] The invention also relates to the use of a coupling element having a parallelepiped shape for coupling light emitted from a light source, the light source facing the side edge of the coupling element, into an inner glass pane acting as a light guide for laminated glazing, the coupling element and the light source being placed on the inner surface P4 of the inner glass pane. Another object of the invention is to provide a coupling element of simplified shape, which, whatever the material of the coupling element, is easy to produce compared to the coupling elements of complex shape used in the prior art.

[0054] In a preferred embodiment, the coupling element has a rectangular shape. Thus, a simple shape can be used to couple the light and produce a laminated glazing with a uniform illumination over the area of ​​the glazing.

[0055] In a preferred embodiment, the coupling element is made of glass. Therefore, the refractive index of the coupling element will be close to the refractive index of the glass panel used to form the glazing. In addition, the coupling element can be cut from a mother panel of glass panels used to form the glazing, thereby simplifying the manufacturing process and reducing costs while maintaining better performance.

[0056] The present invention also encompasses a method for producing a laminate as described in the present invention. The method comprises the following steps:

[0057] a. Providing an exterior glass panel having an exterior surface and an interior surface

[0058] b. Providing an interior glass panel having an exterior surface and an interior surface

[0059] c. Provide optical decoupling between the outer glass panel and the inner glass panel

[0060] d. Lamination of exterior glass panels and interior glass panels with interlayers

[0061] e. Providing a coupling element and a light source onto a portion of the inner surface of the inner glass pane, the coupling element being glass and having a parallelepiped-like shape.

[0062] The coupling elements are as described in the specification.

[0063] Further advantages and advantageous embodiments of the subject matter of the invention can be found in the description, the drawings and the claims.

[0064] An embodiment of a glazing according to the invention, more particularly a vehicle roof with windows, is shown in simplified form in the drawings and is explained in more detail in the following description.

[0065] Figure 1 shows a schematic top plan view of a vehicle roof having a coupling element according to the invention;

[0066] Figure 2 Shown through the Figure 1 A schematic cross section of a vehicle-mounted glass on a vehicle roof;

[0067] Figure 3 A diagram for explaining the present invention and corresponding to Figure 2 A cross-sectional view of the optical properties of laminated glass for vehicles, and Figure 4 A more detailed explanation of light propagation is shown.

[0068] Figure 1 A vehicle roof 10 of a motor vehicle is shown, which is not shown in further detail.

[0069] The vehicle roof 10 is a fixed flush-glass panoramic roof which is divided in this example into three areas (A, B, C) in which the coupling element 30 and the at least one light source 20 are to be arranged. The roof 10 is intended to be fixed to an opening in a vehicle body.

[0070] The glazed vehicle roof 10 is embodied, for example, as a vehicle laminated glazing. The glazing unit according to the invention is preferably mounted on a vehicle in such a way that the inner glass pane is the glass pane in contact with the passenger compartment of the vehicle and the outer glass pane is the glass pane located closer to the exterior of the vehicle (usually in direct contact with the atmosphere outside the vehicle).

[0071] A masking tape 25 is provided along the perimeter of the glazing to protect and hide unsightly elements (e.g., glue, fixtures, etc., fixed to the glazing). Black tape is well known to those skilled in the art. The black tape (usually enamel) may be provided at the perimeter of the inner face P2 of the outer glass panel 11 and / or at the perimeter of the outer face P4 of the inner glass panel 12.

[0072] The interior glass pane 12 may be clear glass, or more preferably the interior glass pane 12 may be extra clear glass.

[0073] The structure is Figure 2 is shown in more detail in .

[0074] In this specific embodiment, the light decoupling layer 13 is arranged between the outer glass pane 11 and the inner glass pane 12 and is configured in particular in this case to decouple the light coupled in the longitudinal direction through the layer at the end side. Furthermore, the light decoupling layer 13 has a surface structure which acts as a decoupling device for the light so that a light emission of the light coupled in laterally is preferably generated via the lower main surface (i.e. through the light decoupling layer 13) with the purpose that a part of the light coupled into the inner glass pane 12 propagates under TIR conditions to be decoupled from the glass pane 12 and emitted towards the passenger compartment (i.e. the vehicle interior), thereby providing an illuminated glazing. In this case, the structure is particularly arranged on the inner face of the layer 13 facing the inner glass pane 12.

[0075] The decoupling is based on the refraction or scattering effect of the light on the structures 13, so that it is emitted at an angle that allows it to exit from the surface of the layer 12. Without such structures, the coupled-in light typically strikes the surface of the layer 12 at a flat angle at which total reflection of the light occurs.

[0076] The surface structure 13 of the layer 12 is produced mechanically, for example by embossing the structure into the surface. Alternatively, the structure can be produced by printing, in particular using pad printing, so that the printed material represents a scattering structure. Another possibility for structuring the surface of the layer 12 consists in etching the surface, by which the surface is roughened to produce a scattering effect. Furthermore, the roughening or structuring can also be achieved by a spraying method, for example by sandblasting.

[0077] The outer glass pane 11 and the inner glass pane 12 are laminated together by an interlayer 14 .

[0078] A thermoplastic interlayer 14 is arranged between the inner face (P2) of the outer glass panel 11 and the optical decoupling layer 13 to laminate the outer glass panel and the inner glass panel. The interlayer 14 can have multiple functions. On the one hand, the interlayer can be used as a laminating layer to produce a permanent bond between the panel 11 and the glass panel 12. In addition, the interlayer 14 can be implemented as a refractive layer, in particular the refractive index of the refractive layer is lower than the refractive index of the optical decoupling layer. Light incident on the interface between the layer 13 and the layer 14 is therefore retained in the optical decoupling layer 13 and does not enter the inner panel 12 (nor the outer panel 11). In this way, light absorption in the panel 11 or light emission from the vehicle to the surrounding environment is avoided. The interlayer 14 is a gray or colored PVB in a preferred embodiment. The thickness of the PVB can be a standard thickness, about 0.75 mm to 0.8 mm. However, the thickness can be less than 0.75 mm. In another embodiment, several thinner interlayers 14 can be stacked. Using grey PVB has the advantage of absorbing the light of the structures 13 to concentrate it inside the glazing and / or ultimately reduce the double image produced on the outer glass pane by the structures 13. This is particularly useful when the glazing is provided with an IR reflecting coating.

[0079] Additionally, the interlayer 14 can perform the function of a splinter protection layer or splinter protection film. For example, for this purpose, the layer 14 is embodied as being made of polyvinyl butyral (PVB).

[0080] The interlayer 14 is preferably arranged such that it serves not only as a laminating layer but also as a refractive layer and, moreover, simultaneously as a fragment protection film. Alternatively, the three functions can also be fulfilled by a corresponding layer structure of a plurality of films. The interlayer extends over the surface of the glass panels 11, 12. Thus, the laminated glazing comprises at least one light source which is arranged to have a surface illumination with improved uniformity. Another object of at least some embodiments is to provide such a surface illumination panel which provides a diffuse and more uniform surface illumination.

[0081] According to an embodiment of the invention, at least one coupling element 30 is fixed to the inner face (P4) of the inner glass panel 12. Preferably, a plurality of coupling elements 30 are arranged along the lateral edges of the glass panel 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 a refractive index that is the same as or close to the refractive index of the inner glass panel 12. The refractive index may be a refractive index higher than the refractive index of the inner glass panel 12.

[0082] Preferably, the refractive index of the coupling element is comprised between 1.48 and 1.59.

[0083] According to an embodiment of the present invention, the coupling element 30 preferably has a flat shape. However, the coupling element can be curved to match the curvature of the roof. Preferably, the coupling element has a rectangular shape. The width, length and height should be adapted accordingly to the light source and the type of glass used to manufacture the coupling element. The dimensions of the coupling element 30 should be adapted according to the specifications of the automobile manufacturer and the type of light source used in order to achieve uniform ambient lighting on the surface of the glazing and more specifically on the surface of the glazing roof.

[0084] Preferably, the height is the same or similar to the height of the inner glass pane 12 used as a light guide, and more preferably is less than the thickness of the inner glass pane 12, thickness and height being used interchangeably in this context.

[0085] Preferably, the coupling element 30 is arranged along at least a portion of the lateral flange of the glazing 10, such as Figure 1 It should be understood that the coupling element and the associated light source can be disposed on the right or left side of the embedded glass to match the desired ambient lighting, but not limited to, the light source can also be disposed on the front or rear side of the embedded glass 10 .

[0086] Preferably, the glass composition of the coupling element 30 is similar to that of the glass composition of the inner glass panel 12. In a preferred embodiment, the coupling element is made of extra-clear glass to have less light absorption and have less losses. The coupling element can be made of a glass with weak absorption. It can potentially be more absorptive than the inner glass panel because the path of light in the coupling element is very short compared to the path in the inner glass.

[0087] According to the invention, the coupling element 30 is arranged near the shielding strip 25, in an area without shielding strips, to minimize the absorption losses of the shielding strips. The term "near" is understood to be close to the shielding strip 25, and the distance between the two is less than 20 cm, more preferably less than 10 cm in this context.

[0088] According to an embodiment of the invention, the light source 20 is arranged in such a way that the light is preferably emitted perpendicularly to the flat edge 310 of the glass coupling element 30. The edge of the coupling element may be curved. Thus, the light emitted by the light source 20 is coupled into the coupling element 30 once it is activated.

[0089] Preferably, the light source 20 and the coupling element 30 are placed in the vicinity of the shielding band, in an area without the shielding band. In an embodiment, only the coupling element is in the area without the shielding band. As mentioned above, the term "near" in this embodiment should be understood to be the same as in the above context.

[0090] The light source 20 is preferably one or more modules including light emitting diodes (LEDs), each module including a plurality of LEDs and associated electronic components secured to a printed circuit board, the modules being positioned such that the emitting faces of the LEDs are oriented toward the edge of the first glass coupling element 30. The light source 20 can be a top emitting LED or a side emitting LED, depending on the intended application, as the coupling element 30 allows for both configurations.

[0091] The light source can be fixed to the edge of the glazing by means of a resin or optical glue. Thus, the light source (especially LED) fixed to the printed circuit board and its associated electronic components are fixed to the edge of the glazing with a polymer material (such as silicon, epoxy resin, polyurethane). Due to the optical resin, the beam shape of the light source can be adjusted. Thus, while maintaining an appropriate level of transparency to allow appropriate light to enter the glass, the light source is protected from moisture.

[0092] The light source 20 may be enclosed in a housing to fix the light source to the glazing and also protect the light source from external influences. The light source 20 may be encapsulated to the edge of the glazing and / or to the edge of the coupling element. The encapsulation means may be an element prepared by injection molding or may be a preformed bead (e.g., an adhesive bead or an elastomer bead) which is applied and fixed at the border of the glazing unit, on the first main face of the first sheet and, if necessary, also on the first main face of the second sheet if the geometry of the border of the glazing unit is suitable.

[0093] The LED can be a side emitting LED or a top emitting LED. Side emitting LEDs form a preferred embodiment. In the case of side emitting LEDs, the LED can be more easily placed perpendicular to the plane of the coupling element 30 to couple well to the coupling element 30 and the interior of the inner glass panel 12.

[0094] In another embodiment, the light source 20 may be a waveguide coupled with an LED, or a diode laser, or an optical fiber.

[0095] In a particular embodiment, the light source 20, and in particular the LED module, is placed along at least a portion of the lateral edge 310 of the coupling element 30. The LED module is then fixed to the glazing 10, for example by means of an encapsulation device.

[0096] According to an embodiment of the present invention, a light guide may be provided between the coupling element 30 and the light source 20. The light guide may be a rod or a rope, and may include, for example, a plastic sheet, a PMMA material and / or a polycarbonate material, an optical fiber (or a fiber bundle), or a silicone material. In some cases, it may be necessary to provide a light guide between the coupling element 30 and the light source 20 because the size of the electronic circuit may not allow direct coupling from the light source 20 to the coupling element 30.

[0097] In a preferred embodiment of the invention, the light source with its own electronic circuit and the light guide in the above described embodiments are integrated into a housing / casing protecting said elements. This preferred embodiment enables fixing / attaching the housing with the light source etc. to the glazing with the coupling element already attached to the second glass pane and also enables aligning the light source with the coupling element for a straight mounting / clamping process and furthermore it facilitates the serviceability of the lighting glazing, in case of a malfunction or any problem the light source can be replaced without any hindrance.

[0098] The coupling element 30 is fixed to the inner face (P4) of the inner glass pane 12. Preferably, the coupling element 30 is fixed by means of an adhesive layer 22.

[0099] The refractive index of the adhesive layer 22 is within the refractive index range of the coupling element 30, or is between the refractive index of the coupling element 30 and the refractive index of the inner glass pane 12 acting as a light guide. Preferably, the refractive index is included between 1.48 and 1.56. As the material of the adhesive layer 22, a pressure-sensitive adhesive, an optically transparent liquid adhesive, EVA, PVB, TPU, an epoxy adhesive, or an acrylic adhesive can be used.

[0100] By internal reflection at the boundary surface of the coupling element 30 , the light is coupled into the inner glass pane 12 serving as a light guide layer via the adhesive layer 22 , and the light can propagate there via internal reflection at the boundary surface.

[0101] Figure 2 is a cross-sectional view for explaining the optical characteristics of the laminated glass according to the present embodiment. The configuration of the laminated glass 10 is similar to Figure 1 and Figure 2 Example configuration shown in .

[0102] The irradiation light A 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 Figure 3 and Figure 4As shown. At this time, the refractive index of air is n1 and the refractive index of coupling element 30 is n2, and when light A enters optical element 30 at an incident angle θ1, the incident light is refracted at an angle of θ1" (n1*sin(θ1)=n2*sin(θ1")), and the refracted light propagates toward adhesive layer 22 at an incident angle θ2. Further, the light propagates into adhesive layer 22 (e.g., optical glue (bonding element)) directly or after being reflected on surface 320, wherein surface 320 is a surface of coupling element 30 that is not affected by adhesive layer 22 or light source 20 (not facing adhesive layer or light source). At this time, the refractive index of bonding element or adhesive layer 22 is n3, and when light enters bonding element at an incident angle θ2, the incident light is refracted at an angle of θ2" (n2*sin(θ2)=n3*sin(θ2")), and the refracted light propagates toward inner glass panel 12 at an incident angle θ3. Further, the light propagates into the second glass 12 through the surface P4. At this time, the refractive index of the second glass is n4, and when the light enters the second glass at an incident angle θ3, the incident light is refracted at an angle of θ3" (n3*sin(θ3)=n4*sin(θ3")), and the refracted light propagates toward the interlayer 14 at an incident angle θ4. 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".

[0103] In order to remain inside the second glass pane 12 by TIR (total internal reflection), the incident angle θ4 of the light must be higher than or equal to the critical angle θ4 C =arcsin(n5 / n4), n5 is the refractive index of the interlayer 14. The condition for total internal reflection is completely straight ahead, which is given here for explanation purposes and Figure 4 It should be understood that the optical decoupling device 13 may not necessarily have its own refractive index, for example, in the case where the optical decoupling device 13 is a surface roughness on the P3 surface of the second glass pane 12, it is obvious that the optical decoupling device 13 may have a refractive index in the case where it is an actual physical layer, and n5 is the refractive index of the optical decoupling device 13 in this case. The present invention aims to improve the coupling efficiency with the coupling element 30 in a simplified and cost-effective manner, and therefore, the present invention is not related to how the optical decoupling device 13 is constructed, because the coupling element made of glass naturally satisfies the condition of total internal reflection in the second glass pane 12.

[0104] The refractive indices of the coupling element and the adhesive layer (bonding element) should be carefully chosen to maximize the coupling efficiency. In case of a wrong choice, the worst case scenario is that no light propagates into the second glass pane 12 by TIR.

[0105] Preferably, n2, n3 and n4 should have the same refractive index, and the coupling element 30 of the present invention can easily meet this condition because in the preferred embodiment, the coupling element 30 is made of the same mother pane as the second glass pane 12.

[0106] The thickness and width of coupling element 30 should be carefully selected to maximize the coupling efficiency of light that can be retained in second glass pane 12 by TIR, i.e., increasing the width of coupling element 30 to a certain level causes more light from light source 20 to be coupled to second glass pane 12.

[0107] The thickness should be kept as small as possible, knowing that the thickness is practically limited by the size of the light source 20. Preferably, a thickness equal to or less than 2 times the thickness of the second glass pane 12 can be considered to have good efficiency.

[0108] The width will be optimized to allow the maximum amount of light to propagate directly toward the second glass pane 12 and to allow a portion of the light to reflect on the surface 320 of the coupling element 30 and then be coupled into the second glass pane 12 by TIR.

[0109] In the above-mentioned embodiment, a low-E coating (low emissivity layer) as a heat radiation reflecting coating can be provided on the surface of the glazed face (P4), more particularly on the glass roof facing the passenger compartment. Therefore, the glazed roof provided with a heat radiation reflecting coating, more particularly a low-E coating, provides the best possible compromise between a view through the roof and good thermal properties due to its long-wave infrared (IR) energy reflection properties.

[0110] According to one embodiment of the invention, the thermal radiation reflecting coating may also be referred to as a coating with low emissivity, a coating with reduced emissivity, a low-E coating or a low-E layer. Its function is to reflect thermal radiation, i.e., in particular IR radiation with a longer wavelength than the IR component of solar radiation. At low external temperatures, the low-E coating reflects heat back into the interior and reduces the cooling of the interior. At high external temperatures, the low-E coating prevents the thermal radiation absorbed by the heated glazing from being re-emitted toward the interior and reduces the heating of the interior. On the inner side of the interior panel, the coating according to the invention is particularly effective in reducing the emission of thermal radiation from the panel into the interior in summer and in reducing the heat transfer to the external environment in winter.

[0111] The choice is to place the coating in position 4, despite the fact that in this position the layers are not protected from degradation, especially mechanical degradation. It is possible to choose a Low-E layer with sufficient mechanical and chemical resistance.

[0112] Advantageously, for good mechanical resistance, the coating is a "hard" layer, such as those produced by PECVD, CVD or pyrolysis techniques. However, low-E systems can also be produced using vacuum cathode sputtering techniques, provided that the system obtained consists of layers with sufficient resistance.

[0113] According to the invention, preference is given to using low-emissivity coating systems having an emissivity below 0.3, preferably below 0.2, particularly preferably significantly below 0.1.

[0114] The most common pyrolytic low-E (low emissivity) systems include a doped tin oxide layer deposited on a first layer having the effect of neutralizing the reflected color. The layer in contact with the glass is usually a silicon dioxide or silicon oxycarbide layer, optionally modified by additives. Compared to the layers of systems deposited by cathode sputtering, the tin oxide layer is relatively thick, i.e., a thickness greater than 200 nm and in some cases greater than 450 nm. These thick layers are sufficiently resistant to withstand exposure to mechanical and / or chemical attack.

[0115] According to an embodiment, an infrared radiation filtering coating may be provided on the inner face (P2) of the outer glass pane. The coating may be provided on the inner face (P3) of the inner glass pane. The coating comprises one or more metal layers substantially based on silver, which are combined with a dielectric layer which protects the metal layer on the one hand. An infrared reflecting coating may be present in the glazing, typically facing the intermediate PVB layer, such coating being positioned in P2 or P3. The infrared reflecting coating preferably comprises n infrared reflecting (IR) layers and n+1 dielectric layers, wherein n≥1, so that each IR layer is surrounded by two dielectric layers. The IR layers may be made of silver, gold, palladium, platinum or alloys thereof, while the dielectric layers may typically comprise 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 function of the IR reflecting coating is to reflect the infrared part of the solar radiation. Typical infrared reflective coatings may be provided by physical vapor deposition to form a coating having a thickness in the range of 10 nm to 250 nm.

[0116] According to an embodiment, a solution (e.g., electrically driven functional film) is provided between the outer glass panel and at least one thermoplastic interlayer for changing the light transmittance of the glazing, adjusting the color tone, privacy, diffuse reflection for thermal protection, and the conditions of use have been proposed. Therefore, the glazing can include a functional film (e.g., an electrochromic device), in which the change is obtained by changing the state of the colored ions in the composition contained in these glazings. Also discussed are the following glazings: these glazings include suspended particle layers that are ordered or disordered according to the application of voltage, such as systems called suspended particle devices (SPDs), or in a preferred embodiment, polymer dispersed liquid crystal (PDLC) films, which consist of polymers containing liquid crystals or guest-host liquid crystals (GHLCs) that are sensitive to the application of voltage. These functional films allow the brightness level in the passenger compartment to be changed, and their function is also to change the anti-glare effect and the privacy level. Another role of these films is to protect the interior of the passenger compartment from heat. In particular, these functional films are films that can be switched between a dark state and a translucent state or even a transparent state.

[0117] The glass panels used to form the laminated glazing unit can have the same composition and possibly the same thickness, which can make them easier to pre-shape, the two sheets being for example bent simultaneously. Most often, the glass sheets have different compositions and / or thicknesses, and in this case they can be shaped individually.

[0118] The possibly present colored interlayers participate in the absorption of light. The use of these colored interlayers can be envisaged as at least partially replacing the contribution of the glass sheets to establishing a specific color. This situation may arise in the following situations: for example, when, in order to integrate photovoltaic elements into a flush-mounted glass unit, at least the outer glass sheets are sheets of poorly absorptive glass or even of extra-transparent glass. However, the outer sheets can also be sheets of absorptive glass and no colored interlayers are required. Therefore, according to one embodiment of the present invention, electrically driven light sources or functional films can be powered thanks to photovoltaic cells. The energy generated by the photovoltaic cells can also be used to power some other elements of the vehicle.

[0119] The inner glass panel facing the passenger compartment can also be made of transparent glass, more preferably of extra-transparent glass. Most often, the glass sheet is absorbent and contributes to a general reduction in energy transfer. When the transmittance of the glass sheet is limited, the glass sheet allows at least partially shielding the opaque elements present in the glazing unit from the passenger's line of sight. The inner glass panel can have a structure of the outer surface (P3) of the inner glass panel itself. The structure is produced mechanically, for example, by embossing the structure into the surface. Alternatively, the structure can be produced by printing, in particular using pad printing, so that the printed material represents a scattering structure. Another possibility for surface structuring of the layer consists in etching the surface, roughening the surface by etching to produce a scattering effect. In addition, the roughening or structuring can also be achieved by a spraying method, for example, by sandblasting.

[0120] The present invention provides a simplified and cost-effective solution to the coupling problem of illuminated vehicle glazings by providing a coupling element made of glass material and preferably the same material as the second glass pane. By means of the present invention, the production of such illuminated glazings is simplified without compromising the performance (i.e. coupling efficiency). In addition, since the coupling element of the present invention is a flat glass with a regular shape, the production of the coupling element does not require additional machining compared to the wedge-shaped coupling prisms known in the prior art, so the production time is significantly reduced.

[0121] The invention includes combinations of the described embodiments.

[0122] For the avoidance of doubt, the present invention is applicable to all vehicles, such as motor vehicles, vans, trucks, motorcycles, buses, trams, trains, airplanes, helicopters, etc. According to embodiments of the present invention, the glazing may be part of the glazing roof, side windows, rear window or windshield of a motor vehicle. The glazing may also be an exterior decal.

[0123] List of Reference Numerals

[0124] 10 Vehicle roof

[0125] 11 External glass panels

[0126] 12 Internal glass panels

[0127] 13 Optical decoupling layer

[0128] 14 Mezzanine

[0129] 20 Light Source

[0130] 30 Coupling element

[0131] 310 Side edge of coupling element

[0132] 320 Surface of coupling element

[0133] 22 Adhesive layer

[0134] 25 Masking tape

Claims

1. A lighting vehicle embedded glass (10), comprising: - an external glass pane (11) having an outer surface (P1) and an inner surface (P2), and - an inner glass pane (12) having an outer surface (P3) and an inner surface (P4), the inner glass pane acting as a light-guiding layer - the outer glass pane and the inner glass panel (11, 12) are laminated together via at least a first plastic interlayer (14), - a light decoupling device (13) arranged between the first plastic interlayer (14) and the inner glass pane (12), a masking strip (25) arranged along the periphery of the inner surface (P2) of the outer glass pane (11) and / or along the periphery of the inner surface (P4) of the inner glass pane (12), a light source (20) arranged on or near the masking strip (25), the light source (20) being placed on the inner surface (P4) of the inner glass pane (12), - at least one coupling element (30), arranged near the light source (20), in an area without a masking strip (25), and substantially bonded to the inner surface (P4) of the inner glass pane (12), the at least one coupling element coupling light emitted by the light source (20) into the inner glass pane, the light source (30) facing a side edge (310) of the coupling element (30); The invention is characterized in that the coupling element (30) is made of glass material.

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

3. The vehicle lighting glazing (10) according to any one of the preceding claims, characterized in that The coupling element (30) has a rectangular shape.

4. The vehicle lighting glazing (10) according to any one of the preceding claims, characterized in that The refractive index of the coupling element (30) is equal to or higher than the refractive index of the inner glass pane (12).

5. The vehicle lighting glazing (10) according to any one of the preceding claims, characterized in that The refractive index of the adhesive layer (22) is between 1.40 and 1.65, and in particular between 1.48 and 1.

56.

6. The vehicle lighting glazing (10) according to any one of the preceding claims, characterized in that The coupling element (30) is attached to the inner surface (P4) of the inner glass pane via an adhesive layer (22).

7. The vehicle lighting glazing (10) according to any one of the preceding claims, characterized in that The light source (20) is preferably an LED strip.

8. The vehicle lighting glazing (10) according to any one of the preceding claims, characterized in that The coupling element (30) has a glass composition similar to the glass composition of the inner glass pane (12).

9. The vehicle lighting glazing (10) according to any one of the preceding claims, characterized in that The optical decoupling device (13) is a light-conducting plastic interlayer.

10. The vehicle lighting glazing (10) according to any one of claims 1 to 8, characterized in that: The light decoupling means (13) is a textured surface (P3) of the inner glass pane.

11. The vehicle lighting glazing (10) according to any one of the preceding claims, characterized in that The embedded glass (10) is a vehicle roof embedded with glass.

12. Use of a coupling element (30) having a parallelepiped shape for coupling light emitted from the light source (20) into the inner glass pane (12) acting as a light guide for the laminated glazing (10), the light source (30) facing the side edge (310) of the coupling element (30), and the coupling element (30) and the light source (20) being placed on the inner surface P4 of the inner glass pane (12).

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

14. Use of a coupling element (30) according to claim 12 or 13, characterized in that The coupling element is made of glass.

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