Glazing for a projection assembly

Abstract

The invention relates to a glazing (100) for a projection assembly (101), comprising: - a composite pane (1) comprising - an outer pane (2), - an inner pane (3), - a thermoplastic intermediate layer (4) arranged between the inner pane (3) and the outer pane (2), - a reflective layer (6) and - a masking element (10), wherein the reflective layer (6) extends over a projection area (P) of the composite pane (1) and the masking element (10) extends over a masking area (M) of the composite pane (1) and the projection area (P) is a partial area of the masking area (M) or identical to the masking area (M), wherein the reflective layer (6) is arranged in front of the masking element (10) of the composite pane (1), looking through the composite pane (1) from the inner pane (3) to the outer pane (2), characterised in that the glazing (100) also comprises an infrared radiation source (5) arranged relative to the composite pane (1) in such a way that water on an exposed surface (IV, VI) in the projection area (P) of the composite pane (1), which is arranged closer to the reflective layer (6) than to the masking element (10), can be irradiated by means of infrared radiation, wherein the infrared radiation source (5) is designed such that it can emit infrared radiation (7) in the infrared wavelength range from 1.3 µm to 3.5 µm.

Description

[0001] Glazing for a projection arrangement

[0002] The invention relates to a glazing for a projection arrangement, a projection arrangement with such glazing and its use.

[0003] Modern automobiles are increasingly being equipped with so-called head-up displays (HIDs). Using a projector, typically located in the dashboard, images are projected onto the transparent viewing area of ​​the windshield, reflected there, and perceived by the driver as a virtual image (as seen from the driver's perspective) behind the windshield. This allows important information to be projected into the driver's field of vision, such as the current speed, navigation information, or warnings, which the driver can perceive without having to take their eyes off the road. Head-up displays can thus significantly contribute to improving road safety.

[0004] In addition to the transparent see-through area, windshields usually have an opaque masking area, which is designed, for example, in the form of an opaque layer through which no vision is possible. The masking area is typically arranged in a peripheral edge region of the windshield and borders the see-through area. The opaque masking area primarily serves to protect the adhesive used to bond the windshield to the vehicle body from UV radiation. The masking area is typically formed by a black masking print on the surface of the outer pane facing the intermediate layer.

[0005] It is also possible to create a virtual image in the masking area of ​​the windshield. For this purpose, the masking area is illuminated by a projector, and the light is reflected there, creating a virtual image in the masking area of ​​the windshield for the driver. For example, information that was previously displayed in the dashboard area, such as the time, driving speed, engine speed, or information from a navigation system, or even the image from a rear-facing camera, which replaces the traditional exterior or rearview mirrors, can be presented directly on the windshield in a practical and aesthetically pleasing manner, for example in the section of the masking area that borders the lower edge of the windshield. A projection arrangement of this type is known, for example, from DE102009020824A1, WO2022238101A1, or WO2022179817A1.

[0006] One problem with projection systems is the visual perceptibility of the information transmitted via the reflected image, regardless of weather / climate conditions. Critical and safety-relevant information must be sufficiently perceptible to the driver in strong sunlight, snow, or rain. When designing a display based on head-up display technology, it is therefore important to ensure that the reflective layer is not inadvertently obscured, for example, by icing or fogging.

[0007] The resulting challenge is how to heat the windshield to prevent icing or fogging, which obstructs visibility. The windshield is typically heated using heated air blown onto the windshield via inlets. This type of heating is collectively referred to as the Heating, Ventilation, and Air Conditioning (HVAC) method. In addition to the enormous energy consumption, the inlets through which the hot air is transported and blown onto the windshield require a great deal of space. Furthermore, the outlet nozzles must be mounted in a specific geometric relationship to the windshield, which in turn significantly limits design and construction freedom.

[0008] Alternatively, the pane itself can have an electrical heating function. For example, DE 103 52 464 A1 discloses a composite pane in which electrically heated wires are inserted between two panes of glass. The specific heating output can be adjusted by the ohmic resistance of the wires. For design and safety reasons, the number and diameter of the wires must be kept as small as possible. The wires must be invisible or barely perceptible in daylight and at night under headlights.

[0009] Transparent electrically conductive coatings, particularly silver-based ones, are also known. Such electrically conductive coatings can be used as coatings with reflective properties for the infrared range or as heatable coatings. However, such metal-based coatings have the disadvantage of being impermeable to all types of electromagnetic radiation. Therefore, panes coated in this way may be less suitable if good data transmission with the external environment is desired.

[0010] WO 2022 / 214369 A1 discloses a projection arrangement with a reflective layer in front of a masking area in a composite pane. The composite pane can be heated via an electrically conductive layer. WO 2022238101 A1 discloses a solution for heating the composite pane in the reflective area. A major problem with heating elements arranged within the composite pane is that they can reduce the stability and light transmission of the composite pane after lamination.

[0011] FR960125A discloses vehicles in which the vehicle window can be heated using coupled IR radiation or direct IR radiation to remove water or frost. Additionally, the frost or fogging on the vehicle windows can be removed by absorbing IR radiation. For this purpose, the vehicle window is directly irradiated.

[0012] All of these solutions have the disadvantage that in order to remove moisture in the form of ice or fogging from the laminated glass, the glass must first be heated to evaporate the water. This results in lower energy efficiency, as the heating is intended solely to remove moisture, but a large portion of the generated heat energy cannot be used for this purpose. This is particularly problematic for electric vehicles, whose range is reduced by low heating efficiency. Furthermore, the evaporation process takes a long time, as the glass must first be heated to a certain temperature for evaporation to occur.

[0013] The object of the present invention is therefore to provide an improved glazing for projection arrangements which can be quickly and energy-efficiently freed from fogging and icing in the projection area and which has a small space requirement and high stability.

[0014] The object of the present invention is achieved according to the invention by glazing according to claim 1, a projection arrangement according to claim 14 and the use of the projection arrangement according to claim 15. Preferred embodiments emerge from the subclaims. The invention relates to glazing for a projection arrangement. According to the invention, the glazing comprises a composite pane and an IR radiation source. The composite pane comprises at least one outer pane, an inner pane and a thermoplastic intermediate layer arranged between the inner pane and the outer pane. The composite pane also comprises at least one reflective layer and a masking element. The reflective layer extends over a projection area of ​​the composite pane and the masking element extends over a masking area of ​​the composite pane.The projection area is a sub-area of ​​the masking area or, alternatively, identical to the masking area. The reflective layer is arranged in front of the masking element of the composite pane when viewed through the composite pane, from the inner pane to the outer pane. This means that the reflective layer is completely concealed by the masking element when viewed through the composite pane, from the outer pane to the inner pane. According to the invention, the IR radiation source is arranged relative to the composite pane in such a way that water on an exposed surface in the projection area of ​​the composite pane can be irradiated with IR radiation. This means that the IR radiation source irradiates the water on the exposed surface either directly with IR radiation or indirectly by first coupling it into the composite pane and then selectively coupling it out in the area covered with water.According to the invention, the exposed surface is positioned closer to the reflective layer than to the masking element. One advantage of the invention is that the water adhering to the exposed surface in the projection area (frost or fogging of the laminated pane, for example, in the form of water droplets) can be removed by means of IR radiation from the IR radiation source.

[0015] The "exposed surface of the laminated pane" refers to a surface that is exposed to the environment. This means that no layers or other elements covering the entire surface are arranged or applied to this surface. The exposed surface can, for example, be an interior-facing surface of the inner pane that faces away from the thermoplastic intermediate layer if this surface is not coated. However, the exposed surface can also be the interior-facing surface of the reflective layer that faces away from the thermoplastic intermediate layer if the reflective layer is applied to the interior-facing surface of the inner pane and no further layers are applied to the interior-facing surface of the reflective layer. Of course, only areas of the interior-facing surface of the reflective layer can be exposed.In the event that the masking element is applied to the interior surface of the inner pane and the reflective layer is applied to the masking element (without further layers following), it is understood that the interior surface of the reflective layer is simultaneously the exposed surface of the laminated pane.

[0016] Looking in the direction from the inner pane to the outer pane or from the outer pane to the inner pane means a view directed perpendicular to the main surface of the composite pane. For the purposes of the invention, projection area and masking area essentially refer to surface areas of the composite pane; the areas therefore essentially extend over the main surface of the composite pane. The fact that the projection area is a sub-area of ​​the masking area means that, when viewed from above, the projection area of ​​the composite pane is located within the masking area or is congruent with the masking area.

[0017] Preferably, the masking area does not extend over the entire composite pane, but only over a partial area, wherein the area of ​​the composite pane not covered by the masking area is preferably a see-through area. The see-through area refers to the area of ​​the composite pane that is intended for seeing through. If the composite pane is a windshield, for example, then the see-through area is the area of ​​the windshield through which the driver can see the roadway or generally the external environment. The projection area refers to an area of ​​the composite pane that is intended to be illuminated by a projector in a projection arrangement so that a virtual image (similar to a HUD image) can be displayed in the projection area. In the present case, the projection area is arranged outside a see-through area of ​​the composite pane.The projection area should not be confused with the projection area of ​​a classic head-up display.

[0018] The outer pane has an outer surface facing away from the thermoplastic intermediate layer, which is also the outer surface of the laminated pane. The outer pane also has an interior surface facing the thermoplastic intermediate layer. The inner pane has an interior surface facing away from the thermoplastic intermediate layer. The interior surface of the inner pane can also be the inner surface of the laminated pane. However, it is also possible for another pane to be arranged on the interior surface of the inner pane via an adhesive layer. In this case, the interior surface of the inner pane is only partially the inner surface (if the additional pane does not extend over the entire interior surface of the inner pane) or not the inner surface of the laminated pane at all.

[0019] The inner pane also has an outer surface facing the thermoplastic intermediate layer. The composite pane is intended to separate an external environment from an interior, preferably a vehicle interior. The outer surface of the outer pane is intended to face the external environment, and the interior surface of the inner pane is intended to face the interior. However, the invention is not limited to this.

[0020] The composite pane has a circumferential edge with an edge surface, which particularly preferably comprises an upper edge and a lower edge as well as two side edges running in between. The upper edge refers to the edge which is intended to point upwards in the installed position. The lower edge refers to the edge which is intended to point downwards in the installed position. The upper edge is often also referred to as the roof edge and the lower edge as the engine edge. The inner pane, the outer pane and, if present, the further pane each have a circumferential edge, which particularly preferably comprises an upper edge and a lower edge as well as two side edges running in between. The circumferential edge of the composite pane is essentially defined by the circumferential edges of the inner pane and the outer pane. The composite pane can have any suitable geometric shape and / or curvature.

[0021] The invention is based on the fact that the water molecules of the water deposited on the exposed surface are caused to vibrate by IR radiation in the wavelength range from 1.3 pm to 3.5 pm, which causes the water to heat up. The heating of the water condensed or frozen on the exposed surface occurs largely selectively, since the panes themselves typically absorb IR radiation much less strongly, and therefore only negligible heating of the composite pane occurs. A resulting advantage is that there is no need for large-area, electrically heatable layers as part of the composite pane, such as silver layers. This leads to simplified, more cost-effective production of the glazing.The permeability of high-frequency radiation, for example, for receiving mobile phone signals, communicating with cloud servers (“Internet of Things”), and the like, is not impaired by the IR radiation source according to the invention, thus resulting in further advantages. IR radiation sources require significantly less space, particularly compared to arrangements for heating the laminated pane using HVAC, which provides another significant advantage. A further advantage arises from the fact that moisture on the exposed surface can lead to unwanted reflections when projecting the projection area, since water has different refractive properties than ambient air. Evaporation also occurs very quickly. The inventors have discovered that evaporation using IR radiation can be many times faster than with the HVAC / coating variant.Another major advantage of this solution is that no heating layer needs to be laminated into the glazing. The arrangement of heating layers or heating wires between two panes and the connection to an electrical power source not only leads to high complexity and high costs, but also to reduced stability of the glazing. As a result, there is increased glass breakage during production, which incurs additional costs. If defects occur in the heating wires, for example due to moisture penetration and the associated corrosion, there is usually no other option than to completely replace the glazing. In the case of the present invention, a simplified repair is possible by replacing the radiation source.

[0022] It is understood that the complete removal of moisture in the projection area on the exposed surface also depends on other conditions such as air humidity, temperature of the laminated glass and the water, radiation intensity, etc. However, the moisture can be removed under suitable conditions: for example, at an air humidity of 50%, a temperature of the glass, the water drop and the environment of 20 °C, a water drop surface area of ​​0.5 cm and a drop coating thickness of 0.3 cm, and an IR irradiance in the projection area of ​​20 W / cm 2 be removed after one minute at the latest. In other words, using the glazing according to the invention, moisture in the projection area on the exposed surface can be removed.

[0023] The projection area preferably extends over more than 5%, preferably over more than 10%, most preferably over more than 15% of the main surface of the composite pane. The masking area preferably extends over more than 7%, preferably over more than 12%, most preferably over more than 17% of the main surface of the composite pane. The projection area can also extend over substantially the same area as the masking area.

[0024] In a preferred first embodiment of the invention, the reflective layer is arranged between the outer pane and the inner pane. It is preferably applied to the outer surface of the inner pane. Alternatively, however, it can also be a reflective film arranged within the thermoplastic intermediate layer. For example, the reflective layer can be arranged as a film during production between two thermoplastic films, which fuse to form the thermoplastic intermediate layer after lamination. The reflective layer can also be applied to the interior surface of the outer pane. In all of the aforementioned cases, this arrangement better protects the reflective layer from external influences, thereby improving the resistance and durability of the reflective layer.

[0025] In a preferred second embodiment of the invention, the glazing additionally comprises a further pane which is arranged via an adhesive layer in the projection area on the interior-side surface of the inner pane. The reflective layer is applied to the interior-side surface of the inner pane or to an exterior surface of the further pane facing the inner pane. The surface of the further pane facing the inner pane is also referred to below as the interior-side surface of the further pane. The surface of the further pane facing the outer pane is also referred to below as the exterior surface of the further pane. The adhesive layer is designed such that the projection of visible light onto the reflective layer is possible through the adhesive layer.

[0026] The additional pane provides better protection for the reflective layer from external influences. At the same time, ghost images caused by reflections on the pane located between the reflective layer and a projector can be better reduced, as the additional pane can be made significantly thinner than, for example, a conventional inner pane of a vehicle window. If the reflective layer is applied to the outer surface of the additional pane, production can also be simplified. The reflective layer does not have to be applied to a partial area of ​​the inner or outer pane, which is generally only possible with high process costs and additional process steps using standard processes such as magnetron sputtering, but can instead be applied to the entire surface of the additional pane, whereby in this case the additional pane preferably extends only over the projection area.

[0027] The reflective layer preferably extends over more than 50%, preferably over more than 70%, very particularly preferably over more than 90%, in particular over the entire interior-side surface of the further pane. In particular, application over a large part (greater than 90%) or the entire surface of the further pane simplifies the manufacturing costs for the further pane with a reflective layer if the reflective layer is applied to the further pane as a coating. The further pane extends at least over the projection area of ​​the composite pane. Preferably, the further pane extends only over the projection area, with the reflective layer in this embodiment extending over the entire surface of the further pane.

[0028] Preferably, the additional pane is connected to the inner pane by means of an adhesive layer. The adhesive layer can be applied directly to the outer surface of the additional pane. It is also possible for the adhesive layer not to be in direct contact with the additional pane, but rather to be applied to the reflective layer, with the reflective layer being applied to the additional pane. Likewise, the adhesive layer can be applied directly to the interior-side surface of the inner pane. It is also possible for the adhesive layer not to be in direct contact with the inner pane, but rather to be arranged, for example, partially or completely on a functional layer or the reflective layer, which is applied to the interior-side surface of the inner pane.

[0029] The adhesive layer, which can also be called a bonding layer, preferably has a light transmittance (according to ISO 9050:2003) of at least 50%, particularly preferably at least 70%, especially when arranged between the reflective layer and the additional pane. The adhesive layer is preferably based on polyurethane, polyacrylate compounds (e.g., polyacrylate or polymethylacrylate), polyvinyl butyral (PVB), ethylene-vinyl acetate copolymer (EVA), or silicone, particularly preferably based on polyurethane, polyacrylate compounds (e.g., polyacrylate or polymethylacrylate), or silicone. Alternatively, the bonding layer is based on mixtures of these materials. These materials allow for a uniform application of the additional pane to the inner pane.In this way, local differences in the thickness of the adhesive layer between the other pane and the inner pane can be largely avoided, which could otherwise impair the aesthetics of the composite pane.

[0030] The additional pane is preferably a thin glass pane. The additional pane is preferably thinner than both the inner pane and the outer pane. The additional pane preferably has a thickness of 50 μm to 1000 μm, more preferably 50 μm to 500 μm, most preferably 100 μm to 400 μm, and in particular 150 μm to 250 μm. This thickness achieves a good ratio of material costs to the mechanical stability of the additional pane. Furthermore, the reflective layer and the additional pane are less aesthetically pleasing, thus improving the optical quality of the composite pane compared to a greater thickness of the additional pane.

[0031] In a preferred third embodiment of the invention, the reflective layer is applied to the interior-side surface of the inner pane. For example, a protective layer can be applied to the surface of the reflective layer facing away from the inner pane to protect the reflective layer from mechanical damage. However, the reflective layer can also be exposed, so that the surface of the reflective layer facing away from the inner pane represents the exposed surface of the composite pane. Ghost images can be avoided when irradiating an exposed reflective layer with a projector, since unwanted reflections cannot occur on the pane arranged between the reflective layer and the projector. The protective layer largely does not lead to a deterioration in the quality of the displayed image.

[0032] The protective layer is preferably a polymer based on polyacrylates, polyoximes, alkyd resins, polyurethanes, or mixtures thereof. Particularly preferably, the protective layer contains or consists of diamond-like amorphous carbon (DLC). The protective layer preferably has a thickness of 50 nm to 10 pm, and particularly preferably of 100 nm to 5 pm. The protective layer is preferably applied to the reflective layer by spraying or atomizing, for example, using a pressure atomizer. The protective layer protects the reflective layer from mechanical damage such as scratches. It can also serve to increase the durability of the reflective layer. With the protective layer, less material separates from the reflective layer on the inner pane over time, and the reflective layer retains its homogeneous shape for longer.

[0033] In a preferred fourth embodiment, which comprises the features of the first embodiment, and in which the IR radiation source is arranged relative to the inner pane such that the IR radiation emitted by the IR radiation source can be coupled into the inner pane and spreads by total internal reflection at least in the projection area of ​​the inner pane. The interior-side surface is the exposed surface of the composite pane. The coupled IR radiation is coupled out into the adhering water on the interior-side surface due to the lower refractive index of water compared to the inner pane. The IR radiation is absorbed and water molecules in ice crystals and water droplets are excited by the IR radiation, which leads to the ice melting and the water evaporating. Energy loss due to convection advantageously largely does not occur.

[0034] In a preferred fifth embodiment, which comprises the features of the second embodiment, and in which the IR radiation source is arranged relative to the further pane such that the IR radiation emitted by the IR radiation source can be coupled into the further pane and propagates through the further pane by means of total internal reflection. A surface of the further pane facing away from the thermoplastic intermediate layer, towards the interior, is here the exposed surface of the composite pane. Similar to what was described for the fourth embodiment, the coupled IR radiation is coupled out into the adhering water due to the lower refractive index of water compared to the further pane on the surface facing the interior.

[0035] Various arrangements of the IR radiation source in relation to the composite pane are possible so that the IR radiation from the IR radiation source can be coupled into the inner pane or the additional pane. The arrangements of the IR radiation source in relation to the composite pane described below apply to both the fourth embodiment and the fifth embodiment. For the sake of simplicity, reference will therefore be made below to the coupling of the IR radiation into “the pane”, which in the case of the fourth embodiment means the inner pane and in the case of the fifth embodiment means the additional pane. The IR radiation source is preferably arranged in an edge region of the composite pane which is intended to be concealed by vehicle parts when installed. The IR radiation source can be arranged in a recess in the pane.The IR radiation source is arranged in the recess in such a way that the IR radiation source can couple IR radiation into the pane, which is then used either to remove condensed moisture or for defrosting. The pane therefore has a recess. This recess is preferably a hole, i.e. a feedthrough, which extends between the interior and exterior surfaces of the pane. Alternatively, the recess can also be a depression in the manner of a blind bore (bag-like depression), which extends from the interior or exterior surface into the pane, but without reaching the opposite surface, which would result in a feedthrough. The recess can be created in the pane, for example, by mechanical drilling or laser processing.The recess is preferably round, but can in principle have any desired shape, for example, even a polygonal shape. This refers to the base area of ​​the recess in the plane of the at least one surface of the disc over which the recess is introduced into the disc. The recess has the overall shape of a cylinder, preferably a vertical cylinder. The cylinder is preferably a circular cylinder (circular base area), but can also have any other base area, for example, an elliptical base area (elliptical cylinder) or a polygonal base area (prism).

[0036] The recess, whether a through-hole or a depression, is defined by a circumferential edge surface extending between the interior and exterior surfaces of the pane. In the case of a through-hole, this is the only boundary surface of the recess. In the case of a pocket-like depression, there is a further boundary surface facing the surface of the pane to which the depression does not extend, forming the bottom of the pocket hole.

[0037] The IR radiation source is arranged on the edge surface of the recess in the pane, preferably attached, in particular glued, or arranged in a mount attached to the recess. The IR radiation is then coupled into the pane via the inner edge surface and, due to the lower refractive index of water, selectively coupled out of the pane in areas of icing or condensed moisture.

[0038] Alternatively, the IR radiation source can be arranged on at least one section of the peripheral edge surface of the pane. The IR radiation source is, for example, assigned to at least one side edge surface or attached to two opposite side edge surfaces and / or to the upper and / or lower edge of the pane, for example, glued or arranged in a mount attached to the pane. Preferably, the IR radiation source is arranged on a section of the peripheral edge surface of the pane that is closest to the projection area.

[0039] As an alternative to being arranged in a recess in the pane or on a section of the circumferential edge, the IR radiation source can also be arranged on the interior surface of the pane. On the exterior surface of the pane, however, an IR mirror layer, i.e. a reflective coating for the infrared range, is applied, which, when viewed through the composite pane, overlaps the IR radiation source. The pane is thus irradiated with IR radiation via the interior surface. The IR radiation source is attached to the interior surface of the pane, for example, glued with an optically clear adhesive (OCA). This couples the IR radiation into the pane via reflection from the IR mirror layer.This reduces the complexity of the glazing, as the radiation source does not have to be positioned on the edge surfaces of the pane, especially not in a recess in the pane. An optically clear adhesive is preferably a material that contains or is made from polyacrylate compounds (e.g., polyacrylate or polymethylacrylate) or silicone. "Clear" in the context of the invention means that the adhesive is transparent.

[0040] When an IR mirror layer is used for coupling, the IR radiation from the IR radiation source is (at least partially) reflected back towards the pane by the IR mirror layer, where the IR radiation is coupled into the pane using the principle of total internal reflection. This helps to distribute the IR radiation within the pane and direct it to the areas to be heated, i.e., the icy or moist projection area of ​​the composite pane. IR mirror layers are known per se and can be formed, for example, as a silver-containing coating or as a layer of an electrically conductive oxide (transparent conductive oxide, TCO), such as indium tin oxide (ITO). Alternatively, the IR mirror layer can also be applied to the pane in the form of a coated thermoplastic film, for example made of polyethylene terephthalate (PET).The IR mirror layer is preferably a prism film, which can be additionally coated with an IR-reflecting coating based on an electrically conductive oxide. In particular, the IR mirror layer is a microprism film, which can be additionally coated with an IR-reflecting coating based on an electrically conductive oxide. The inclined surfaces of the prism film result in the IR rays being reflected at a particularly advantageous angle by the IR mirror layer, so that they hit the pane at an angle of incidence at which a particularly high proportion of the IR radiation can be coupled in.

[0041] Alternatively, the IR radiation source can be applied to the outside surface or the inside surface of the pane using an optically clear adhesive in the shape of an inclined wedge. The IR radiation source is preferably applied in the edge region of the pane. For the purposes of the invention, "inclined wedge" refers to a wedge shape having two substantially triangular side surfaces, two base surfaces, and one base surface. The base surfaces and the base surface can have any shape conceivable in this context, for example, substantially rectangular, triangular, or round, preferably substantially rectangular. The triangular side surfaces are not rectangular, so the two base surfaces are different sizes.The base surface is the smallest of the surfaces of the inclined wedge and is arranged at an angle greater than 90° to one of the base surfaces and at an angle less than 90° to the other base surface. In this embodiment, the optically clear adhesive is applied to the pane such that the base surface is at an angle of less than 90° to the base surface of the wedge, which is in contact with the surface of the pane. The IR radiation source is arranged such that the IR radiation first transmits through the optically clear adhesive before then penetrating the pane, with the IR radiation being at least partially coupled into the pane using the effect of total internal reflection. The IR radiation source is arranged such that, during operation, it irradiates the base surface of the optically clear adhesive, with the emitted IR radiation preferably impinging on the optically clear adhesive perpendicular to the base surface.This base surface of the optically clear adhesive preferably has an angle to the surface of the pane that is suitable for coupling IR radiation into the pane. The optically clear adhesive preferably has a refractive index that differs by less than 0.1, preferably less than 0.05, from the refractive index of the pane. As a result, the IR radiation is refracted less strongly at the interface between the optically clear adhesive and the pane. Nevertheless, any existing radiation refraction between the optically clear adhesive and the pane can be taken into account when selecting the angle of the base surface to the pane surface.

[0042] Refractive indices in the context of the present invention are generally given relative to a wavelength of 1500 nm. Methods for determining refractive indices are known to those skilled in the art. The refractive indices specified in the context of the invention can be determined, for example, by ellipsometry, using commercially available ellipsometers. Unless otherwise stated, the specification of layer thicknesses or thicknesses refers to the geometric thickness of a layer.

[0043] Preferably, the IR radiation source is arranged in the masking area, but outside the projection area, of the composite pane, so that the IR radiation source is completely covered when viewed through the composite pane. The IR radiation sources can thus be optically concealed from the outside. To prevent the masking area from blocking the coupling of the IR radiation into the pane, a small recess of the masking area can be provided in the area of ​​the IR beam path, i.e., a small area that is not covered by the masking element.

[0044] For the purposes of the invention, the “complete occlusion / coverage of an element A with an element B” means that the orthonormal projection of element A to the plane of element B is arranged completely within element B.

[0045] Mixtures and combinations of the above-described embodiments are also possible. For example, the pane can be irradiated and heated with an IR radiation source on the lower edge and additionally with another IR radiation source on the interior-side surface of the pane. Likewise, an IR radiation source can be arranged in a recess in the pane and an additional IR radiation source can directly irradiate the exposed surface of the composite pane. These are only exemplary embodiments and are not to be understood as exhaustive. In a preferred sixth embodiment of the invention, the IR radiation source is arranged relative to the composite pane such that the emitted IR radiation impinges on the exposed surface of the composite pane in the projection area. In other words: the IR radiation source irradiates the exposed surface directly.This has the advantage that the radiation intensity can be adjusted much more easily, and the IR radiation source does not have to be positioned in direct contact with the composite pane. Preferably, the IR radiation source is positioned relative to the composite pane such that it can essentially only irradiate the masking area; in particular, the IR radiation source is positioned relative to the composite pane such that it can essentially only irradiate the projection area.

[0046] The IR radiation source is preferably arranged at a distance of no more than 30 cm, preferably no more than 20 cm, particularly preferably no more than 10 cm, and especially no more than 5 cm, from the exposed surface of the laminated pane. If the laminated pane is, for example, a vehicle windshield, the IR radiation sources can be arranged, for example, in the dashboard. In this case, the projection area is preferably located in a lower region of the windshield adjacent to the dashboard. At a shorter distance, water removal from the laminated pane is more efficient. The area to be irradiated can also be more selectively adjusted.The distance between the IR radiation source and the exposed surface of the laminated pane refers to the shortest distance from the emission surface of the IR radiation source, i.e. the surface from which the IR radiation leaves the radiation source, to the exposed surface of the laminated pane.

[0047] Another preferred embodiment provides that the IR radiation source is connected to at least one control unit and / or on-board electronics. The IR radiation source can be controlled by the control unit and / or the on-board electronics. Preferably, the control unit or the on-board electronics serve as the voltage source for the IR radiation source.

[0048] In a further embodiment of the invention, the glazing comprises at least one additional IR radiation source, preferably at least two additional IR radiation sources, which are arranged relative to the composite pane in such a way that water on the exposed surface in the projection area of ​​the composite pane can be irradiated by IR radiation from the IR radiation source, with the aim of removing the moisture in this area. The radiation sources can preferably be switched and operated independently of one another. Thus, the associated radiation sources can be controlled independently of one another, allowing the intensity to be selectively adjusted.

[0049] In a further preferred embodiment of the invention, the masking region is arranged in an edge region of the composite pane directly adjacent to a section of the circumferential edge of the composite pane. The masking region preferably extends along the circumferential edge of the composite pane and can be widened in the section overlapping the projection region. The composite pane preferably has a transmittance (according to ISO 9050:2003) for visible light of less than 15%, preferably less than 10%, particularly preferably less than 1% in the masking region. The low transmittance of the composite pane is preferably essentially attributable to the masking element. The masking element is preferably opaque. The composite pane can also be semi-transparent, at least in sections, in the masking region, for example as a dot matrix, striped matrix, or checkered matrix.Preferably, however, the masking area is not semi-transparent in the area overlapping the projection area. Alternatively, the composite pane can also have a gradient in the masking area, for example, from an opaque coating to a semi-transparent coating. "Width" in the context of the invention refers to the extent perpendicular to the direction of extension.

[0050] The masking element, which according to the invention extends over the masking area, is designed, for example, in the form of an opaque enamel or an opaque thermoplastic film. The masking element can also be a partially opaque thermoplastic film and thus be a component of the thermoplastic intermediate layer. The masking element is designed, in particular, in the form of a dark, preferably black, enamel (also called screen printing), which is applied to the outer pane. The masking element is preferably applied to the interior-side surface of the outer pane. The masking element can serve as UV protection for the assembly adhesive of the composite pane (for example, for bonding it into a vehicle).

[0051] The composite pane can also have several, preferably two, masking elements, wherein preferably a first masking element according to the invention is applied in the masking region on the interior-side surface of the outer pane, and a second masking element is applied on the interior-side surface of the inner pane in a further masking region. The further masking region can extend across the composite pane independently of the masking region according to the invention and can also partially or completely overlap with the masking region according to the invention.

[0052] In a particularly preferred further embodiment of the invention, the opaque masking region is arranged in a frame-like manner in the peripheral edge region of the composite pane and is widened in a section of the peripheral edge region adjacent to the lower edge and / or the upper edge of the composite pane. In this case, the projection region is also located in the section adjacent to the lower edge and / or the upper edge. The masking region preferably has a width of 10 cm or more, particularly preferably 20 cm or more, in particular 30 cm or more, in the widened region. This embodiment is particularly suitable for use in vehicles in which a projection arrangement is used as an alternative to displays installed in the dashboard.Alternatively, the masking area may extend only over a lower edge area of ​​the composite pane adjacent to the lower edge and / or over an upper edge area of ​​the composite pane adjacent to the upper edge.

[0053] The reflective layer preferably reflects visible light by at least 10%, particularly preferably by at least 40%, most particularly preferably by at least 70%. The reflective layer preferably reflects visible light by at most 90%. For the purposes of the invention, reflection within a specific percentage range means an averaged reflectance at a defined angle of incidence (65°). The reflective layer is intended to reflect an image projected onto the reflective layer by a projector. The reflective layer can be transparent, but is preferably opaque.

[0054] For the purposes of the invention, "opaque" means a light transmission (according to ISO 9050:2003) for visible light of less than 30%, preferably less than 20%, particularly preferably less than 5%, and especially less than 0.1%. "Transparent" for the purposes of the invention means a light transmission (according to ISO 9050:2003) for visible light of at least 50%, preferably at least 60%, and particularly preferably at least 70%. The reflective layer is designed to reflect light in a wavelength range from 380 nm to 780 nm (visible light). Preferably, the reflective layer is also an IR radiation-reflecting layer. This accelerates the removal of moisture from the exposed surface and saves energy. The reflective layer preferably has a reflectance for infrared radiation of at least 10%, particularly preferably at least 20%, most preferably at least 40%, and especially at least 50%.The reflective layer preferably reflects p-polarized and s-polarized visible light in equal proportions, but it can also reflect p-polarized and s-polarized light to varying degrees. The reflective layer preferably exhibits a high and uniform reflectance (across different angles of incidence) of p-polarized and / or s-polarized radiation, ensuring a high-intensity and color-neutral image. Reflecting p-polarized light results in fewer ghost images, thus improving the visual quality of the reflected light (e.g., a virtual image). The reflectance can be increased by adding s-polarized light.

[0055] The reflectance is measured at an angle of incidence of 65° to the interior surface normal (the surface normal is the vector perpendicular to the interior surface of the laminated glass), which roughly corresponds to the irradiation from common projectors / radiation sources in vehicles. The reflectance describes the proportion of the total incident radiation, for example, visible radiation or radiation in the IR wavelength range, that is reflected. It is expressed as a percentage (relative to 100% incident radiation) or as a unitless number from 0 to 1 (normalized to the incident radiation). Plotted as a function of wavelength, it forms the reflection spectrum.In the context of the present invention, the statements regarding the reflectance (or percentage reflection) with respect to p-polarized, unpolarized, or s-polarized radiation refer to the reflectance measured at an angle of incidence of 65° to the interior surface normal. The information on the reflectance or the reflection spectrum refers to a reflection measurement with a projector or an IR radiation source that radiates uniformly in the considered spectral range with a standardized radiation intensity of 100%.

[0056] The reflective layer preferably comprises at least one metal selected from a group consisting of aluminum, magnesium, tin, indium, titanium, tantalum, niobium, tungsten, nickel, copper, chromium, cobalt, iron, manganese, zirconium, hafnium, cerium, scandium, yttrium, silver, gold, platinum, palladium, ruthenium, or mixtures thereof. Alternatively or additionally, the reflective layer comprises oxides, carbides, silicon compounds, and / or nitrides selected from a group consisting of boron-doped silicon, silicon-zirconium mixed nitride, silicon nitride, titanium oxide, silicon oxide, titanium carbide, zirconium carbide, silicon-zirconium-aluminum, or mixtures thereof. Aluminum, titanium, nickel-chromium, and / or nickel are preferably applied to the further pane because they exhibit high reflection for p-polarized or s-polarized light. They are therefore particularly suitable as a component of a projection arrangement.The reflective layer preferably has a thickness of 10 nm (nanometers) to 100 pm (micrometers), particularly preferably from 50 nm to 50 pm, in particular from 100 nm to 5 pm.

[0057] In a further embodiment of the invention, the reflective layer is a coating comprising a thin-film stack, i.e., a sequence of thin individual layers. This thin-film stack contains one or more electrically conductive layers based on nickel, nickel-chromium, titanium, and / or aluminum. The electrically conductive layer based on nickel, nickel-chromium, titanium, and / or aluminum imparts basic reflective properties to the reflective layer, as well as an IR-reflecting effect and electrical conductivity. The electrically conductive layer is based on nickel, nickel-chromium, titanium, and / or aluminum. The conductive layer preferably contains at least 90 wt.% nickel, titanium, and / or aluminum, more preferably at least 99 wt.% aluminum, and most preferably at least 99.9 wt.% nickel, titanium, and / or aluminum.The layer based on aluminum, nickel-chromium, nickel, and / or titanium can contain dopants, for example palladium, gold, copper, or silver. Materials based on aluminum, nickel, nickel-chromium, and / or titanium are particularly suitable for reflecting light, particularly preferably p-polarized light. The use of nickel, nickel-chromium, titanium, and / or aluminum in reflective layers has proven particularly advantageous for reflecting light. Aluminum, nickel, nickel-chromium, and / or titanium are significantly cheaper than many other metals such as gold or silver. In addition, these metals have high chemical and thermomechanical resistance. The individual layers of the thin-film stack preferably have a thickness of 10 nm to 1 pm. The thin-film stack preferably has 2 to 20 individual layers, and in particular 5 to 10 individual layers.

[0058] In a particularly preferred embodiment of the invention, the reflective layer is a metal-free reflective film. The reflective layer is then preferably a film that functions on the basis of synergistically interacting prisms and reflective polarizers. The reflective layer preferably has a carrier film based on polyvinyl chloride or polyethylene terephthalate. Synergistically interacting prisms and reflective polarizers are applied to this carrier film. In this way, complex metal deposition can be avoided. The reflective layer is applied as a reflective film, preferably via an adhesive layer, to the interior-side surface of the additional pane or is arranged between the inner pane and the outer pane, particularly preferably within the thermoplastic intermediate layer.

[0059] The IR radiation source is designed in such a way that, according to the invention, it can emit IR radiation in the IR wavelength range from 1.3 pm to 3.5 pm, preferably from 2.5 pm to 3.3 pm, particularly preferably from 2.6 pm to 2.9 pm. It is not necessary for the emission band of the IR radiation source to completely cover the aforementioned ranges. However, the emission band should lie (at least partially) within these ranges. The radiation source is expediently connected to a power supply device. It is precisely in this preferred wavelength range that the absorption and excitation of the water molecules, and thus the resulting heating and evaporation, is particularly high. Advantageously, it has been shown that with glass the transmission in the wavelength range from 2.9 pm to 3.1 pm is particularly high at over 70%, and in particular at approx. 3.0 pm at approx. 85%, so that the energy can be used efficiently for defrosting and evaporating water.

[0060] In an alternative embodiment, the radiation source is configured such that it can emit IR radiation in the IR wavelength range from 1.4 pm to 2 pm, preferably from 1.45 pm to 1.95 pm. In this range, the radiation is particularly energy-intensive and thus very suitable for evaporating water. This wavelength range is particularly preferred if the radiation source comprises or consists of an LED, since LEDs with radiation in higher wavelength ranges above 2 pm are difficult to manufacture and can thus be expensive.

[0061] The IR radiation source preferably comprises an LED, OLED, and / or a laser diode, preferably an LED. In particular, the IR radiation source comprises an LED, which can also be referred to as an "IR radiation-emitting diode." Furthermore, the IR radiation source can comprise laser diodes or lasers, which have the advantage of being particularly powerful and efficient. In addition to the aforementioned elements for generating IR radiation, the IR radiation source can also comprise further elements, for example, a housing in which the elements for generating IR radiation are mounted. Alternatively, the IR radiation source can be an LED, OLED, and / or a laser diode.

[0062] In a particularly preferred embodiment of the invention, the IR radiation source comprises or consists of an Er:YAG diode. The Er:YAG diode has a wavelength of approximately 2960 nm. This wavelength corresponds to the wavelength range in which water molecules exhibit the highest absorption coefficient. Other examples are InAs / GaSb and Er3+-doped sesquioxide diodes.

[0063] The IR radiation sources can be strip-shaped or spot-shaped, for example. Other geometric shapes are also possible. Several individual IR radiation sources can also be arranged next to one another, spaced apart, or in a strip-shaped arrangement (close to one another). In other words, if several spot-shaped LEDs are arranged next to one another, a multi-part, strip-shaped IR radiation source can be formed. This allows the number and intensity of the IR radiation sources to be flexibly adapted to the requirements for heating the composite pane, for example, with regard to the spatial and geometric conditions and the energy required for efficient heating.

[0064] The outer pane and the inner pane are preferably made of transparent glass, in particular soda-lime glass, which is common for window panes. In principle, however, the panes can also be made of other types of glass (e.g. borosilicate glass, quartz glass, aluminosilicate glass) or transparent plastics (e.g. polymethyl methacrylate or polycarbonate). The thickness of the outer pane and the inner pane can vary widely. Preferably, panes with a thickness in the range of 0.8 mm to 5 mm, more preferably 1.4 mm to 2.5 mm, for example those with the standard thicknesses of 1.6 mm or 2.1 mm, are used. The outer pane, the inner pane and, if present, the additional pane can independently of one another be untempered, partially tempered or tempered. If at least one of the panes is to be tempered, this can be thermal or chemical prestressing.

[0065] The outer pane, the inner pane (if present), the additional pane, and the composite pane can have any three-dimensional shape. Preferably, the inner pane, the additional pane, and / or the outer pane have no shadow zones, allowing them to be efficiently coated by cathode sputtering. Preferably, the inner pane, the additional pane, the outer pane, and thus also the composite pane are flat or slightly or strongly curved in one or more directions of the room. The additional pane is preferably curved in the same shape as the inner pane in the projection area.

[0066] The thermoplastic intermediate layer is preferably formed as at least one thermoplastic composite film and is based on ethylene-vinyl acetate (EVA), polyvinyl butyral (PVB), or polyurethane (PU), or mixtures or copolymers or derivatives thereof, particularly preferably based on polyvinyl butyral (PVB), and additionally contains additives known to those skilled in the art, such as plasticizers. The thermoplastic film preferably contains at least one plasticizer.

[0067] The thermoplastic intermediate layer can be formed by a single film or by more than one film. The thermoplastic intermediate layer can be formed by one or more thermoplastic films arranged one above the other, wherein the thickness of the thermoplastic intermediate layer after lamination of the layer stack is preferably from 0.25 mm to 1 mm, typically 0.38 mm or 0.76 mm. The thermoplastic intermediate layer can also be formed from a film that is colored in some areas and is thus opaque. The masking element can also be a component of the thermoplastic intermediate layer. The intermediate layer can also be formed from more than one film, and the at least two films can extend over different regions of the surface of the composite pane.

[0068] The thermoplastic intermediate layer may also be a functional thermoplastic film, in particular a film with acoustic damping properties, an infrared radiation reflecting film, an infrared radiation absorbing film and / or a UV radiation absorbing film.

[0069] If something is "based" on a polymeric material, it consists predominantly of this material, i.e. at least 50%, preferably at least 60%, and in particular at least 70%. It can therefore also contain other materials such as stabilizers or plasticizers. A further aspect of the invention relates to a projection arrangement comprising glazing according to the invention and a projector which is arranged and suitable for projecting an image in the form of visible radiation (visible light) onto the projection area, in particular onto the reflective layer, of the composite pane. In other words: the projector can irradiate the projection area of ​​the composite pane, in which the reflective layer is arranged, with visible light, the reflective layer at least partially reflecting the visible light. The projector preferably faces the interior-side surface of the inner pane.If the laminated pane is in an installed state (for example as a windshield in a vehicle), the projector irradiates the projection area from an interior space (vehicle interior).

[0070] The radiation from the projector preferably has a p-polarized component > 0%. In principle, the p-polarized component can also be 100%, meaning the projectors can emit purely p-polarized radiation. For the overall intensity of the projected image, however, it is advantageous if the radiation from the projector has both s-polarized and p-polarized components. The direction of polarization refers to the plane of incidence of the radiation on the composite pane. P-polarized radiation refers to radiation whose electric field oscillates in the plane of incidence. S-polarized radiation refers to radiation whose electric field oscillates perpendicular to the plane of incidence. The plane of incidence is spanned by the incidence vector and the surface normal of the composite pane in the geometric center of the irradiated area.

[0071] If the projection system is part of a vehicle, the projector is preferably located in the vehicle's dashboard. The image projected by the projector in the projection area is reflected into the vehicle interior, for example, into the field of vision of an occupant. Due to the reflective layer arranged in front of the masking element, the image projected onto the reflective layer can be visually perceived with high contrast. This allows the use of projectors with lower energy requirements. Compared to projectors for conventional head-up displays, the projector's energy consumption can be reduced by up to 80%. A particularly significant advantage is that reflective layers with a high degree of reflection for visible light can be selected, and the reflective layer can also be reflective for IR radiation, which makes the removal of icing and moisture from the laminated glass more efficient.

[0072] The projector and / or the optionally additional projector are preferably a liquid crystal (LCD) display, thin film transistor (TFT) display, light emitting diode (LED) display, organic light emitting diode (OLED) display, electroluminescent (EL) display or microLED display.

[0073] A further aspect of the invention relates to a process for producing the glazing according to the invention. The process steps include, in the order given, the following process steps:

[0074] (A) Arrangement of the outer pane, the inner pane, the thermoplastic intermediate layer, the reflective layer and the masking element to form a layer stack,

[0075] (B) Lamination of the layer stack to form the composite pane and

[0076] (C) Arrangement of the IR radiation source relative to the composite pane such that water arranged on the exposed surface in the projection area of ​​the composite pane can be irradiated by IR radiation from the IR radiation source.

[0077] The lamination of the layer stack takes place under the influence of heat, vacuum and / or pressure, whereby the outer and inner panes are bonded (laminated) together by at least one thermoplastic film. Known processes for producing a composite pane can be used. For example, so-called autoclave processes can be carried out at an elevated pressure of approximately 10 bar to 15 bar and temperatures of 130°C to 145°C for approximately 2 hours. Known vacuum bag or vacuum ring processes operate, for example, at approximately 200 mbar and 130°C to 145°C. The layer stack can also be pressed into a composite pane in a calender between at least one pair of rollers. Systems of this type are known for producing composite panes and usually have at least one heating tunnel upstream of a pressing unit. The temperature during the pressing process is, for example, between 40°C and 150°C.Combinations of calendering and autoclave processes have proven particularly effective in practice. Alternatively, vacuum laminators can be used. These consist of one or more heatable and evacuatable chambers in which the outer pane and the inner pane can be laminated within, for example, approximately 60 minutes at reduced pressures of 0.01 mbar to 800 mbar and temperatures of 80°C to 170°C. The glazing according to the invention can be, for example, the roof pane, windshield, side window, or rear window of a vehicle or other vehicle glazing, for example a partition pane in a vehicle, preferably in a rail vehicle, a car, or a bus. Alternatively, the glazing can be architectural glazing, for example in an exterior facade of a building or a partition pane inside a building, or a built-in component in furniture or appliances.

[0078] A further aspect of the invention relates to the use of the projection arrangement in a vehicle, wherein the glazing is a vehicle window, preferably the windshield, of the vehicle.

[0079] The invention is explained in more detail below using exemplary embodiments, with reference to the accompanying figures. The figures are schematic representations and not to scale. The figures do not limit the invention in any way. They show:

[0080] Fig. 1 shows an embodiment of the glazing according to the invention in a plan view,

[0081] Fig. 2 is a cross-sectional view of a projection arrangement with the glazing of

[0082] Fig. 1 ,

[0083] Fig. 3 is an enlarged cross-sectional view of an edge area of ​​the glazing from Fig. 1

[0084] Fig. 4-5 further embodiments of the glazing according to the invention in an enlarged cross-sectional view and

[0085] Fig. 6 an absorption spectrum of water (liquid state).

[0086] 1 to 3 show different aspects of an embodiment of the glazing 100 according to the invention and the projection arrangement 101. Fig. 1 shows the glazing 100 according to the invention with a composite pane 1 in the form of a windshield for a vehicle. The composite pane 1 is shown in a plan view, looking onto an interior-side surface IV of the composite pane 1. Fig. 2 shows the glazing 100 as a component of a projection arrangement 101 according to the invention in a cross-sectional view, wherein the projection arrangement 101 is installed in a vehicle. The cross-sectional view of Fig. 2 corresponds to the section line AA' of the composite pane 1, as indicated in Fig. 1. Fig. 3 shows an enlarged cross-sectional view of the glazing 100, showing the lower edge region of the glazing 100 from Fig. 2.

[0087] The composite pane 1 has an upper edge and a lower edge, as well as two side edges connecting the upper and lower edges (all together forming a circumferential edge of the composite pane 1). The lower edge (also called the engine edge) of the composite pane 1 refers to the edge that faces the ground in the installed position. The upper edge (also called the roof edge) of the composite pane 1 refers to the edge that faces the vehicle roof when installed in a vehicle.

[0088] The composite pane 1 comprises an outer pane 2, an inner pane 3 and a thermoplastic intermediate layer 4 arranged between the outer pane 2 and the inner pane 3. The outer pane 2 has an outer surface I facing away from the thermoplastic intermediate layer 4 and an interior-side surface II facing the thermoplastic intermediate layer 4. The inner pane 3 has an outer surface III facing the thermoplastic intermediate layer 4 and an interior-side surface IV facing away from the thermoplastic intermediate layer 4. The outer surface I of the outer pane 2 is also simultaneously an exposed surface of the composite pane 1, which faces the external environment 15, and the interior-side surface IV of the inner pane 3 is also simultaneously an exposed surface of the composite pane 1, which faces the interior 14 of the vehicle.The laminated pane 1, for example, has a shape and curvature typical for windshields.

[0089] The outer pane 2 and the inner pane 3 are each made of glass, preferably thermally toughened soda-lime glass, and are transparent to visible light 13 and IR radiation 7. The outer pane 2 has, for example, a thickness of 2.1 mm, and the inner pane 3 has, for example, a thickness of 1.5 mm. The thermoplastic intermediate layer 4 comprises a thermoplastic material, preferably polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), and / or polyethylene terephthalate (PET), for example, with a thickness of 0.76 mm.

[0090] A masking element 10 is applied to the interior-side surface II of the outer pane 2 in a masking area M. A further masking element 10' is applied to the interior-side surface IV of the inner pane 3. The opaque masking area M with the masking element 10 and the further masking element 10' extend in a frame-like manner along the circumferential edge of the composite pane 1. The masking area M is wider in the lower edge area directly adjacent to the lower edge of the composite pane 1, in contrast to the upper edge area directly adjacent to the upper edge of the composite pane 1; the masking element 10 is therefore applied wider in the lower edge area. The masking element 10 and the further masking element 10' are opaque and prevent the view of structures arranged on the inside or outside of the composite pane 1, for example an adhesive bead for bonding the composite pane 1 into a vehicle body.The masking elements 10, 10' consist of an electrically non-conductive material conventionally used for black printing, for example a black-colored screen printing ink that is baked.

[0091] A reflective layer 6 is applied in regions on the outer surface III of the inner pane 3. The reflective layer 6 extends over a projection area P, which is intended to be irradiated by a projector 12. The projection area P is a partial area of ​​the masking area M, so that the reflective layer 6 is arranged in front of the masking element 10 when viewed from the interior 14 through the composite pane 1. Conversely, this means that the masking element 10 completely covers the reflective layer 6 when viewed through the composite pane 1, as seen from the external environment 15. The projection area P is located in the lower edge area of ​​the composite pane 1. The further masking element 10' does not cover the reflective layer 6 when viewed through the composite pane 1, regardless of whether viewed from the interior 14 or from the external environment 15.The reflective layer 6 is applied to the inner pane 3, for example, by magnetron sputtering. The reflective layer 6 is, for example, a dielectric layer stack containing TiCh layers and SiCh layers. The reflective layer 6 is designed, for example, to reflect at least 30% of visible light 13.

[0092] A projector 12 is arranged on a dashboard 16 of the vehicle, which projects a virtual image in the form of visible radiation (light) 13 onto the reflective layer 6 in the projection area P of the laminated pane 1. The angle of incidence at which the visible light 13 of the projector 12 strikes the interior-side surface IV of the inner pane 3 is, for example, 65°. The projector 12 irradiates the projection area P of the laminated pane 1. The visible light 13 of the projector 12 is reflected by the reflective layer 6 toward a viewer, and the reflected light 13 is visually perceived by a viewer (for example, the driver of the vehicle).

[0093] At the lower edge of the composite pane 1, more precisely at the lower edge of the inner pane 3, an IR radiation source 5, for example an LED for IR radiation 7 with a wavelength in a wavelength range of A = 1.3 pm to 3.5 pm, is arranged. The IR radiation source 5 can, for example, be an Er:YAG diode which has a wavelength of approximately 2960 nm. This wavelength corresponds to the frequency and wavelength range in which water molecules have the highest absorption coefficient for the IR radiation 7. At the same time, the transmission of glass in this IR radiation range <3.5 pm is particularly high with a transmittance of approximately 85% and only a small part is absorbed. The LEDs can, for example, be glued on or arranged in a holder fastened to the inner pane 3. In this embodiment, the IR radiation source 5 is designed and / or arranged in a strip-shaped manner.The arrows indicate, by way of example and schematically, the radiation direction of the IR radiation 7. The IR radiation 7 is coupled into the inner pane 3 via the edge surface of the inner pane 3. Furthermore, the IR radiation source 5 can be functionally connected to a control and / or regulating unit, for example, to the on-board electronics of a vehicle (not shown here).

[0094] In areas on the inner pane 3 on which moisture 11 has deposited, i.e. where the inner pane 3 is covered, for example, with water droplets 11 or ice crystals, the IR radiation 7 is selectively coupled out. This coupling out is related to the lower refractive index for water 11 compared to the glass of the inner pane 3, since water is a less optically dense medium than the glass of the inner pane 3. The IR radiation 7 is absorbed by the water molecules, which are heated by the excitation by the IR radiation 7 and thereby evaporated. A particular advantage of the invention is that IR radiation 7 in particular can be used with as precise a wavelength and in the frequency range as possible in which water molecules have the highest absorption coefficients, and in this way a very selective heating effect can be achieved. This contributes to achieving the heating effect in a particularly energy-saving manner.

[0095] Energy efficiency is an extremely important criterion for future product developments. Advantageously, the heating effect according to the invention does not depend on the heating of the glazing 100 itself, but is achieved selectively through the excitation of the water molecules by the IR radiation 7. Therefore, the heating effect occurs much more quickly than with previously used heating devices, and additionally, there is no heat loss due to convection and the large surface area of ​​the glazing 100. Thus, the dependence of the effect on the outside temperature is significantly lower than with previously known heating devices, which must first heat the glazing 100 to ultimately remove condensate and ice.The rapid evaporation of water 11 on the interior-side surface IV of the inner pane 3 in the projection area P also prevents, in particular, undesired light reflections from occurring due to the light 13 of the projector 12 reflecting on the water 11, which shows the great advantage of the invention for glazings 100 intended for use in projection arrangements.

[0096] Reference is now made to Figs. 4 and 5, which show enlarged cross-sectional views of various embodiments of the glazing 100. The cross-sectional views of Figs. 4 and 5 correspond to the section line AA' in the lower edge region adjacent to the lower edge of the composite pane 1. The variants shown in Figs. 4 and 5 essentially correspond to the variant from Figs. 1 to 3, so that only the differences will be discussed here, and otherwise reference is made to the description of Figs. 1 to 3.

[0097] Unlike the variant from Figs. 1 to 3, the opaque masking element 10 in the variant from Fig. 4 is not formed by a screen print applied to the outer pane 2. The masking element 10 is formed here as a colored area, for example, colored black, of the thermoplastic intermediate layer 4. The colored area of ​​the thermoplastic intermediate layer 4 simultaneously serves as the masking element 10. Furthermore, the reflective layer 6 is applied here to the interior surface IV of the inner pane 3, instead of to the exterior surface III.

[0098] In the embodiment of Fig. 4, the IR radiation source 5 is not arranged at the lower edge of the inner pane 3, but rather, for example, in the area of ​​the dashboard 16 (dashboard 16 not shown in Fig. 4). The IR radiation source 5 does not radiate the IR radiation 7 into the inner pane 3, so that the radiation 7 is coupled into the inner pane 3. Instead, the projection area P is irradiated directly by the IR radiation source 5. The IR radiation 7 strikes, for example, at an angle of approximately 65° the surface of the reflective layer 6 facing the interior 14, which here is the exposed surface of the laminated pane 1 in the projection area P. Fig. 5 shows an embodiment of the glazing 100 according to the invention, in which the reflective layer 6 is applied to the interior surface IV of the inner pane 3 instead of to the exterior surface III.The reflective layer 6 is protected from external influences by a further pane 8. The further pane 8 is arranged via an adhesive layer 9 on the surface of the reflective layer 6 facing the interior 14. The further pane 8 and the adhesive layer 9 extend over the projection area P of the composite pane 1. It would also be conceivable for the reflective layer 6 to be applied alternatively to the outer surface V of the further pane 8 facing the inner pane 3 (not shown here). The further pane 8 consists, for example, of soda-lime glass and has a thickness of 200 μm. The adhesive layer 9 is, for example, based on a polyacrylate and has, for example, a thickness of 100 μm.

[0099] In the embodiment of Fig. 5, the IR radiation source 5 is not arranged at the lower edge of the inner pane 3, but for example in the area of ​​the dashboard 16 (not shown in Fig. 5). The IR radiation source 5 does not radiate the IR radiation 7 into the inner pane 3, so that the IR radiation 7 is coupled into the inner pane 3. Instead, the projection area P is irradiated directly by the IR radiation source 5. The IR radiation 7 strikes, for example, the interior-side surface VI of the further pane 8 facing the interior 14 at an angle of approximately 65°, which here is the exposed surface of the composite pane 1 in the projection area P. In principle, it would also be conceivable for a (further) IR radiation source 5 to be arranged additionally or exclusively relative to the further pane 8 in such a way that the IR radiation 7 can be coupled into the further pane 8 (not shown here).The IR radiation source 5 could optionally be arranged on a lower edge of the further pane 8.

[0100] Fig. 6 shows an absorption spectrum of water in the liquid state. The diagram shows that water molecules, for example, have a particularly high absorption coefficient at a wavelength of approximately 3 pm. In a preferred embodiment, an IR radiation source in the IR wavelength range from 2.5 pm to 3.3 pm, particularly preferably from 2.9 to 3.1 pm, is used for the glazing, since the absorption and excitation of the water molecules, and thus the resulting heating and evaporation, is particularly high in this preferred wavelength range.

[0101] 1 composite pane

[0102] 2 outer pane

[0103] 3 inner pane

[0104] 4 thermoplastic intermediate layer

[0105] 5 IR radiation source

[0106] 6 reflective layer

[0107] 7 IR radiation

[0108] 8 more slices

[0109] 9 Adhesive layer

[0110] 10 Masking element

[0111] 10' additional masking element

[0112] 11 Water (moisture)

[0113] 12 projectors

[0114] 13 visible light

[0115] 14 Interior

[0116] 15 external environment

[0117] 16 Dashboard

[0118] 100 glazing

[0119] 101 Projection arrangement

[0120] P Projection area

[0121] M Masking area

[0122] I outside surface of the outer pane 2

[0123] II Interior surface of the outer pane 2

[0124] III outer surface of the inner pane 3

[0125] IV Interior surface of the inner pane 3

[0126] V outer surface of the further pane 8

[0127] VI Interior surface of the further pane 8

[0128] AA' section line

Claims

Patent claims 1. Glazing (100) for a projection arrangement (101), comprising: a composite pane (1) comprising an outer pane (2), an inner pane (3), a thermoplastic intermediate layer (4) arranged between the inner pane (3) and the outer pane (2), a reflective layer (6), and a masking element (10), wherein the reflective layer (6) extends over a projection area (P) of the composite pane (1), and the masking element (10) extends over a masking area (M) of the composite pane (1), and the projection area (P) is a partial area of ​​the masking area (M) or is identical to the masking area (M), wherein the reflective layer (6) is arranged in front of the masking element (10) of the composite pane (1) when viewed through the composite pane (1), from the inner pane (3) to the outer pane (2), characterized in that the glazing (100) further comprises an IR radiation source (5),which is arranged in relation to the composite pane (1) in such a way that water on an exposed surface (IV, VI) in the projection area (P) of the composite pane (1), which is arranged closer to the reflection layer (6) than to the masking element (10), can be irradiated by means of IR radiation, wherein the IR radiation source (5) is designed in such a way that it can emit IR radiation (7) in the IR wavelength range from 1.3 pm to 3.5 pm., 2. Glazing (100) according to claim 1, wherein the reflection layer (6) is arranged between the outer pane (2) and the inner pane (3), preferably applied to an outer surface (III) of the inner pane (3) facing the thermoplastic intermediate layer (4).

3. Glazing (100) according to claim 1, further comprising a further pane (8) which is arranged via an adhesive layer (9) in the projection area (P) on an interior-side surface (IV) of the inner pane (3) facing away from the thermoplastic intermediate layer (4), and the reflection layer (6) is applied to the interior-side surface (IV) of the inner pane (3) or an exterior surface (V) of the further pane (8) facing the inner pane (3).

4. Glazing (100) according to claim 1, wherein the reflection layer (6) is applied to an interior-side surface (IV) of the inner pane (3) facing away from the thermoplastic intermediate layer (4).

5. Glazing (100) according to claim 2, wherein the IR radiation source (5) is arranged relative to the inner pane (3) in such a way that the IR radiation (7) emitted by the IR radiation source (5) can be coupled into the inner pane (3) and spreads by means of total reflection at least in the projection area (P) of the inner pane (3), wherein an interior-side surface (IV) of the inner pane (3) facing away from the thermoplastic intermediate layer (4) is the exposed surface (IV) of the composite pane (1).

6. Glazing (100) according to claim 3, wherein the IR radiation source (5) is arranged in relation to the further pane (8) in such a way that the IR radiation (7) emitted by the IR radiation source (5) can be coupled into the further pane (8) and propagates in the further pane (8) by means of total reflection, wherein an interior-side surface (VI) of the further pane (8) facing away from the thermoplastic intermediate layer (4) is the exposed surface (VI) of the composite pane (1).

7. Glazing (100) according to one of claims 1 to 4, wherein the IR radiation source (5) is arranged relative to the composite pane (1) such that the emitted IR radiation (7) impinges on the exposed surface (IV, VI) of the composite pane (1) in the projection area (P).

8. Glazing (100) according to claim 7, wherein the IR radiation source (5) is arranged at a distance of at most 30 cm, preferably at most 20 cm, particularly preferably at most 10 cm, from the exposed surface (IV, VI) of the composite pane (1).

9. Glazing (100) according to one of claims 1 to 8, wherein the masking region (M) is arranged in an edge region immediately adjacent to a portion of a circumferential edge surface (II) of the composite pane (1).

10. Glazing (100) according to one of claims 1 to 9, wherein the reflective layer (6) contains silicon, aluminum, titanium, zirconium, nickel, chromium, boron-doped silicon, silicon-zirconium mixed nitride, silicon nitride, titanium oxide, silicon oxide, titanium carbide, zirconium carbide, silicon-zirconium-aluminum and / or mixtures thereof.

11. Glazing (100) according to one of claims 1 to 10, wherein the masking element (10) is in the form of a black enamel which is applied to the outer pane (2).

12. Glazing (100) according to one of claims 1 to 11, wherein the IR radiation source (5) is designed such that it can emit IR radiation (7) in the IR wavelength range from 1.4 pm to 2 pm.

13. Glazing (100) according to one of claims 1 to 12, wherein the reflective layer (6) is also an IR radiation-reflecting layer and preferably has a reflectance for IR radiation (7) of at least 10%.

14. Projection arrangement (101) comprising a glazing (100) according to one of claims 1 to 13 and a projector (12) which is intended to project visible radiation (10) onto the projection area (P) of the composite pane (1).

15. Use of the projection arrangement (101) according to claim 14 in a vehicle, wherein the glazing (100) is a vehicle window, preferably the windshield, of the vehicle.

Images