CN113905887A

CN113905887A - Vehicle glazing with electroluminescent device and optical band stop filter

Info

Publication number: CN113905887A
Application number: CN202180001594.6A
Authority: CN
Inventors: K·菲舍尔; J·哈根; R·齐默曼
Original assignee: Saint Gobain Glass France SAS
Current assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Priority date: 2020-04-29
Filing date: 2021-03-12
Publication date: 2022-01-07
Also published as: WO2021219285A1; DE202021004037U1

Abstract

The invention relates to a vehicle glazing made of an outer glazing panel (1) and an inner glazing panel (2), the outer and inner glass panes are joined to each other by means of a thermoplastic interlayer (3), the vehicle glass pane is equipped with an electroluminescent device (20, 30) and an optical band-stop filter (40, 50) with a blocking range, wherein the optical band stop filter (40, 50) is constructed as a thin layer coating made of alternately arranged optically high refractive index layers with a refractive index larger than 1.8 and optically low refractive index layers with a refractive index smaller than 1.8, the average wavelength of the radiation emitted by the electroluminescent arrangement (20, 30) is located within the blocking range of the optical band stop filter (40, 50), and-the optical band-stop filter (40, 50) is arranged such that radiation of the electroluminescent device (20, 30) through the outer glass plate (1) or through the inner glass plate (2) is blocked. The half-value width (Delta lambda) of the blocking range of the band-stop filter (40, 50) is 10 nm to 50 nm.

Description

Vehicle glazing with electroluminescent device and optical band stop filter

The invention relates to a vehicle glazing with an electroluminescent device and an optical band-stop filter and a vehicle equipped with the vehicle glazing.

It is known to equip vehicle glazing with electroluminescent devices. Depending on the application, the electroluminescent arrangement can be designed here as a surface light source according to the LED or OLED type, or in the form of individual light-emitting diodes (LED, light-emitting diode). The surface light source can be incorporated into the thermoplastic interlayer of the composite glass pane, for example in the form of an electroluminescent film. The discrete light-emitting diodes can likewise be embedded in the thermoplastic interlayer of the composite glass pane or fixed in one of the individual glass panes of the composite glass pane, for example. Vehicle glazing with electroluminescent devices is known, for example, from DE102016209914, WO2017203132 or WO 2017103426.

The electroluminescent arrangement has a defined radiation direction which is mostly directed towards the interior of the vehicle. Thus, for example, vehicle roof panes are known whose electroluminescent device serves to illuminate the vehicle interior. Windscreens are also known, whose electroluminescent device is used to generate a display for the driver.

However, the radiation of the electroluminescent arrangement is not directed or is directed only to a small extent. All these applications therefore have in common that the electroluminescent arrangement radiates not only in the set radiation direction, but also in the opposite direction. If the electroluminescent device is arranged in the visible region of the vehicle glazing, unwanted radiation cannot be prevented by opaque elements, for example a peripheral covering print. Radiation into undesired directions is at least disruptive, even if not completely unacceptable to the user.

WO2017103426a1 discloses a vehicle glazing with an electroluminescent device. In the radiation direction of the electroluminescent arrangement, a color filter may be present to filter out part of the white radiation of the electroluminescent arrangement and thus provide color to the radiation. The color filter may be configured as a dielectric interference filter made of alternating optically high and low refractive index layers. In the opposite direction, the radiation is prevented by the opaque cover print.

US20150228696a1 discloses another vehicle glazing with an electroluminescent device. US20150228696a1 also teaches that radiation in undesired directions can be prevented by reflective elements. The reflective element can be constructed as a metal-containing coating or as a dielectric mirror.

WO2014029536a1 discloses vehicle glazing with switchable functional elements, which may be, for example, electroluminescent devices. The vehicle glazing has an infrared reflective coating to protect the functional elements from damage caused by the infrared portion of the solar radiation.

DE102017003621a1 discloses another vehicle glazing with an electroluminescent arrangement, in which radiation into undesired directions is prevented by an opaque cover print.

It is an object of the present invention to provide a vehicle glazing with an electroluminescent device in which radiation into undesired radiation directions is prevented or at least significantly reduced.

According to the invention, the object of the invention is achieved by a vehicle glazing according to claim 1. Preferred embodiments follow from the dependent claims.

The invention is based on the combination of an electroluminescent device with an optical band stop filter. The band-stop filter is matched in terms of its optical properties to the radiation of the electroluminescent arrangement and is arranged so as to overlap the electroluminescent arrangement in such a way that radiation is prevented into the external environment or into the vehicle interior. The band stop filter is constructed as a thin layer coating, which acts as an interference filter. The band-stop filter can therefore be adjusted very precisely in terms of its optical properties and integrated into the vehicle glazing without being visually noticeable. This is a major advantage of the present invention.

The vehicle glass panel according to the invention is configured as a composite glass panel. It comprises an outer glass pane and an inner glass pane, which are joined to one another by means of a thermoplastic interlayer. The vehicle glazing is provided for separating a vehicle interior space from an exterior environment in a window opening of the vehicle. In the sense of the present invention, an inner glass pane denotes a glass pane of the vehicle glass pane which faces the interior space in the mounted position. The outer glass sheet represents a glass sheet facing the outside environment.

The outer and inner glass panes have outer and inner space side surfaces, respectively, and a peripheral side edge extending therebetween. In the sense of the present invention, an outside surface denotes a main surface which is provided for facing the outside environment in the mounted position. In the sense of the present invention, an interior space side surface denotes a main surface which is provided for facing the interior space in the mounted position. The inner space side surface of the outer glass sheet and the outer side surface of the inner glass sheet face each other and face the thermoplastic interlayer, and are joined to each other through the thermoplastic interlayer.

The intermediate layer of the vehicle glass pane is formed by at least one layer of thermoplastic material (joining material). The intermediate layer may consist of said one layer of thermoplastic material and is formed, for example, by a single polymer film or cast resin layer. However, the intermediate layer may also comprise a plurality of layers of thermoplastic material and be formed, for example, from a plurality of polymer films which are arranged one above the other in a planar manner.

According to the invention, the vehicle glazing is equipped with an electroluminescent device. Electroluminescent devices may also be referred to as electroluminescent-type devices. In contrast to multi-color devices, electroluminescent devices are preferably monochromatic, i.e. emit radiation of only one color. Monochromatic radiation can be prevented particularly effectively by a band-stop filter, since the band-stop filter is typically optimized for one color. In the case of a multicolor electroluminescent device, a variety of band-stop filters may be used.

The electroluminescent arrangement can be designed, for example, as an electroluminescent film, in particular in accordance with the type of LED or OLED (organic light-emitting diode ), and as a surface light source. The electroluminescent film comprises an active layer containing an electroluminescent material and being contacted on both sides by transparent electrode layers (for example made of silver or ITO) and, as an outer layer, electrically insulating carrier layers sandwiching therebetween the active layer with the electrodes. Alternatively, the electroluminescent arrangement is formed, for example, by a plurality of light-emitting diodes, which then form discrete, approximately point-like light sources. All light emitting diodes preferably have the same emission color. By means of electrical excitation, the electroluminescent arrangement emits electromagnetic radiation in the visible spectral range.

Preferably, the electroluminescent device is arranged in a transparent region of the glass plate which is not provided with an additional opaque element. The invention is particularly advantageous here.

Furthermore, according to the invention, the vehicle glazing is equipped with an optical band-stop filter. The optical band-stop filter is constructed as a thin layer coating made of an optical high refractive index layer and an optical low refractive index layer. The optically high refractive index layer has a refractive index greater than 1.8 and the optically low refractive index layer has a refractive index less than 1.8. Within the scope of the present invention, the data on the refractive index are based on a wavelength of 550 nm. The optical high refractive index layers and the optical low refractive index layers are alternately arranged, i.e. alternately on top of each other. Preferably, the thin layer coating includes n optically high refractive index layers having a refractive index greater than 1.8 and n optically low refractive index layers having a refractive index less than 1.8, where n is a natural number greater than or equal to 1. Particularly preferably, the thin-layer coating consists of n optical low-refractive-index layers and (n +1) optical high-refractive-index layers, each arranged alternately. The uppermost and lowermost layers of the coating are correspondingly optically high refractive index layers. Thereby achieving an optimal interference effect. However, the thin-layer coating can also consist of n optically low-refractive-index layers and n optically high-refractive-index layers, or of (n +1) optically low-refractive-index layers and n optically high-refractive-index layers, even if the interference effect is therefore generally weak.

An optical band-stop filter is an optical filter that blocks, i.e. significantly reduces (in particular due to reflection) the transmission of electromagnetic radiation in a specific spectral range, whereas electromagnetic radiation with smaller and larger wavelengths is mostly transmitted, i.e. only slightly or not significantly reduced. The spectral range in which radiation is blocked is called the blocking range. The band-stop filter appears to be a complementary counterpart of the optical band-pass filter. The optical performance of a band-stop filter can be quantitatively described by a series of parameters used in the context of the present invention as follows:

-the center wavelength represents the center point of the blocking range;

-minimum transmittance represents the minimum transmittance value occurring in the blocking range;

the blocking depth describes the difference between the transmission value occurring at the local transmission maximum adjacent to the blocking range and the minimum transmission. If the transmission values of the local transmission maxima differ on both sides of the blocking range, the average value should be used;

the width of the blocking range is called the bandwidth and can be described as the half-value width. The upper and lower limits of the bandwidth are defined as the wavelength at which the filter reaches 50% of the blocking depth, i.e. the transmission value that occurs is 50% of the blocking depth plus the minimum transmission;

the slope describes the spectral range over which the filter transitions from high barrier to high transmission. At both limits of the blocking range, the slope may be determined as the spectral range between the wavelength where 80% of the blocking depth is reached (transmission value is 80% of the blocking depth plus minimum transmission) and the wavelength where 10% of the blocking depth is reached (transmission value is 10% of the blocking depth plus minimum transmission).

In the sense of the present invention, the transmission is measured at an angle of incidence of 0 ° to the surface normal, which results in a transmission spectrum as a wavelength-dependent curve.

The radiation emitted by the electroluminescent device is within the blocking range of the optical band stop filter. In the sense of the present invention, this is satisfied in particular when the mean wavelength of the electroluminescent radiation lies "within the bandwidth (half-value width) of the band-stop filter", i.e. the difference between the center wavelength of the band-stop filter and the mean wavelength of the electroluminescent radiation is less than half the half-value width of the band-stop filter. The mean wavelength of the electroluminescent radiation is then located within the blocking range of the band-stop filter. The half-value width of the band-stop filter should be larger than the half-value width of the electroluminescence spectrum of the electroluminescent device. Preferably, the sum of half the half-value width of the electroluminescent radiation and the difference between the center wavelength of the band-stop filter and the average wavelength of the electroluminescent radiation is less than half the half-value width of the band-stop filter. A particularly good blocking effect is thereby achieved. The minimum transmission of the band-stop filter is preferably less than 20%. The half-value width of the band stop filter (more precisely: the half-value width of the blocking range of the band stop filter) is preferably at least 10 nm, for example from 10 nm to 50 nm, particularly preferably from 20 nm to 50 nm, very particularly preferably from 20 nm to 30 nm. Preferably, at least 50% (more precisely: at least 50% of the intensity of the radiation emitted in the direction of the band stop filter) of the radiation of the electroluminescent arrangement is not transmitted by the band stop filter, particularly preferably at least 70%.

The blocking range of the band-stop filter is in the visible spectral range of 380 nm to 780 nm. The blocking range of the band-stop filter is preferably located completely within the visible spectral range so that it does not extend beyond the boundaries of the visible spectral range. The blocking range does not of course cover the entire visible spectral range, but preferably has a half-value width in the above-mentioned range.

The optical band-stop filter is arranged in or on the vehicle glazing such that radiation of the electroluminescent device through the outer glazing or through the inner glazing is blocked, i.e. prevented or at least significantly reduced. Thus, radiation of the electroluminescent device through a glass plate selected from the group consisting of the outer glass plate and the inner glass plate is blocked by the band-stop filter. The electroluminescent device radiates into the environment through another glass sheet selected from the outer glass sheet and the inner glass sheet. In particular, radiation passing through the further glass plate is not prevented (for example by opaque elements such as cover prints) or significantly specifically attenuated (for example by band-stop filters). Of course, the radiation can also be attenuated slightly by elements of the vehicle glazing which do not specifically act on the radiation of the electroluminescent device, for example by the glazing itself or a coating located thereon.

The band-stop filter preferably allows at most 50% of the incident radiation of the electroluminescent arrangement to pass, i.e. the degree of blocking is at least 50%. For this purpose, the band stop filter and the electroluminescent arrangement are arranged one above the other in a perspective through the vehicle glazing, which means that the orthogonal projection of the electroluminescent arrangement onto the plane of the band stop filter is arranged completely within the band stop filter. Depending on the set radiation direction of the electroluminescent arrangement, the optical band stop filter can be arranged on the outer side or on the inner space side with respect to the electroluminescent arrangement. The arrangement of the band stop filter on the outside in the sense of the present invention means that the band stop filter is arranged closer to the outside environment of the vehicle, i.e. with a smaller distance to the outside environment, in the mounted position than the electroluminescent arrangement. This occurs when the set radiation direction is directed towards the vehicle interior space. In this case, radiation of the electroluminescent device to the external environment, i.e. through the outer glass pane, is prevented or at least reduced. In contrast, the arrangement of the band stop filter on the side of the interior space means in the sense of the invention that the band stop filter is arranged closer to the vehicle interior space, i.e. with a smaller distance to the vehicle interior space, than the electroluminescent arrangement in the mounted position. This occurs when the set radiation direction is directed towards the external environment. In this case, the radiation of the electroluminescent device into the interior space of the vehicle, i.e. through the inner glass pane, is prevented or at least reduced.

When the band stop filter is arranged on the outer side with respect to the electroluminescent arrangement, the following configuration is possible in particular:

the electroluminescent device is arranged on the inner space side surface of the inner glass pane. The band elimination filter is arranged on the outer side surface of the inner glass plate, in the intermediate layer, on the inner space side surface of the outer glass plate or on the outer side surface of the outer glass plate;

the electroluminescent device is arranged on the outer side surface of the inner glass plate. The band elimination filter is arranged in the middle layer, on the side surface of the inner space of the outer glass plate or on the outer side surface of the outer glass plate;

the electroluminescent arrangement is arranged in the intermediate layer. A band-stop filter arranged within the intermediate layer between the electroluminescent device and the outer glass pane, on the inner-space-side surface of the outer glass pane or on the outer-side surface of the outer glass pane;

the electroluminescent device is arranged on the inner space-side surface of the outer glass pane. The band-stop filter is disposed on an outer side surface of the outer glass plate.

When the band stop filter is arranged on the side of the interior space with respect to the electroluminescent arrangement, the following configuration is possible in particular:

the electroluminescent device is arranged on the outer side surface of the inner glass plate. The band elimination filter is arranged on the inner space side surface of the inner glass plate;

the electroluminescent arrangement is arranged in the intermediate layer. A band-elimination filter is arranged in the intermediate layer between the electroluminescent device and the inner glass plate, on the outer side surface of the inner glass plate or on the inner space side surface of the inner glass plate;

the electroluminescent device is arranged on the inner space-side surface of the outer glass pane. The band elimination filter is arranged in the middle layer, on the outer side surface of the inner glass plate or on the inner space side surface of the inner glass plate;

the electroluminescent device is arranged on the outer side surface of the outer glass plate. The band-stop filter is arranged on the inner space-side surface of the outer glass plate, in the intermediate layer, on the outer side surface of the inner glass plate or on the inner space-side surface of the inner glass plate. However, this configuration is less preferred, since the electroluminescent arrangement is exposed substantially unprotected to adverse effects from the external environment and in particular may be easily damaged.

If the band-stop filter is arranged in an intermediate layer, a thin-layer coating is typically deposited on a carrier film, which is arranged between two layers of thermoplastic joining material. The carrier layer is, for example, a polyethylene terephthalate (PET) -based film having a thickness of 10 μm to 100 μm.

If the electroluminescent device is arranged in an intermediate layer, it can likewise be arranged on a carrier film which is arranged between two layers of thermoplastic joining material. Thus, a plurality of light-emitting diodes with their electrodes can be arranged, for example, on a carrier film. It is also possible to arrange the electroluminescent arrangement configured as an electroluminescent film between two layers of thermoplastic bonding material. However, the light-emitting diode can also be fused directly in the thermoplastic bonding material, for example over the interface of the two layers of thermoplastic bonding material.

If the electroluminescent device is arranged on the surface of one of the glass plates, it can be mounted on a flat surface and fixed there, for example by means of an adhesive or laminated thereon by means of a thermoplastic interlayer (if it is the surface facing the interlayer). If the electroluminescent device is designed as individual light-emitting diodes, these can also be installed in recesses in the surface, which are designed, for example, as bores in a glass plate.

Vehicle glazing is also known in which electroluminescent devices, such as LEDs or optical fibres, are arranged on the side edges of the inner or outer glazing. The radiation is coupled into the respective glass pane via the side edges and propagates within the glass pane as a result of total reflection at the surface. In this case, the glass plate is provided with light-scattering structures, for example screen-printed or roughened areas, at which the radiation is coupled out of the glass plate. The light-scattering structures now form a perceptible illuminated area. The invention is also applicable to vehicle glazing in which the positioning of the band stop filter is then accordingly not dependent on the position of the actual electroluminescent device, but on the position of the light scattering structure. The band stop filter and the light scattering structure are arranged overlapping in a perspective through the vehicle glazing, which means that the orthogonal projection of the light scattering structure onto the plane of the band stop filter is arranged completely within the band stop filter. Depending on the radiation direction set, the optical band stop filter can be arranged on the outer side or on the inner space side with respect to the light scattering structure.

The present invention is applicable to a number of technical applications, including the following:

the electroluminescent device is arranged to radiate outwards to prevent transmission through the vehicle glazing (the "privacy" glazing). The electroluminescent device is in particular an electroluminescent film, and the band-stop filter is arranged on the interior side with respect to the electroluminescent device. Preferably, the electroluminescent film is embedded in the intermediate layer. The vehicle glass panel is preferably a vehicle roof glass panel;

the electroluminescent arrangement is arranged for inward radiation to form a display element. The electroluminescent device is in particular an electroluminescent film or a plurality of light-emitting diodes. The band-stop filter is arranged on the outside with respect to the electroluminescent arrangement. Preferably, the electroluminescent device is arranged between the outer and inner glass panes, in the form of an insert in the intermediate layer or on one of the surfaces of the glass panes facing each other. The vehicle glazing is preferably a windscreen panel;

the electroluminescent device is arranged to radiate inwardly as a light source to illuminate the vehicle interior space. The electroluminescent device is in particular a plurality of light-emitting diodes. The band-stop filter is arranged on the outside with respect to the electroluminescent arrangement. The vehicle glazing is preferably a vehicle roof glazing.

The optical band-stop filter is constructed as a sequence of thin layers, wherein the optical high refractive index layers and the optical low refractive index layers are alternately stacked on top of each other. An optical band-stop filter is an interference filter, wherein radiation passing through the filter is (predominantly) reflected or (predominantly) transmitted depending on its wavelength due to interference effects. The interference is due to reflection of the radiation at the interfaces of the layers, which results in multiple superpositions of the radiation. Depending on the path length between the interfaces, interference is constructive or destructive at a given wavelength, and the filtering effect is due to this.

The optical band-stop filter can be provided with properties desired for the application by the structure of the thin-layer stack. In particular, the refractive index of the material of the individual layers, the thickness of the individual layers and the total number of individual layers play a role here. The refractive index and the geometric thickness of the individual layers (the product of which yields the so-called optical path length or optical thickness) influence, inter alia, the center wavelength of the band-stop filter, i.e. the spectral position of the blocking range. In principle, the more monolayers a thin-layer stack comprises, the more accurate the optical filter performance can be designed. Thus, a layer system consisting of a large number of individual layers can be used to produce a band-stop filter with a low minimum transmission, a large blocking depth and a small slope. The bandwidth is also affected by the number of layers, with a greater number of layers resulting in less bandwidth.

The thin-layer stack of the band-stop filter usually contains a dielectric, optically high-refractive-index layer. These may be based, for example, on silicon nitride (Si)₃N₄) Silicon-metal mixed nitrides (e.g., zirconium silicon nitride, silicon-aluminum mixed nitrides, silicon-hafnium mixed nitrides, or silicon-titanium mixed nitrides), aluminum nitride, titanium oxide, tin zinc oxide, zirconium oxide, niobium oxide, hafnium oxide, tantalum oxide, tungsten oxide, manganese oxide, bismuth oxide, or silicon carbide. Silicon nitride, silicon-metal mixed nitrides (in particular zirconium silicon nitride) and titanium oxide are preferred because of their good optical properties, their resistance and their good depositability, in particular by vapor deposition.

The thin-layer stack of the band-stop filter usually contains a dielectric and/or an electrically conductive optical low-refractive index layer. For example, the dielectric optically low refractive index layer may be based on silicon oxide (SiO)₂) Aluminum oxide, magnesium fluoride, silicon oxynitride, or calcium fluoride. Silicon oxide is preferred because of its good optical properties, its resistance and good depositability.

The material may be deposited in a stoichiometric, sub-stoichiometric or super-stoichiometric manner. The material may have a dopant, in particular aluminum, boron, zirconium or titanium. By doping, a certain conductivity can be provided to the material. However, the person skilled in the art will recognize this as a dielectric layer in terms of its function, as is common in the field of thin layers. The material of the dielectric layer preferably has a thickness of less than 10^-4Conductivity (inverse of specific resistance) of S/mNumber). The material of the conductive layer preferably has a value of more than 10⁴Conductivity of S/m.

The refractive index of the optically high refractive index layer is preferably at least 2.0, and the refractive index of the optically low refractive index layer is preferably at most 1.6, particularly preferably at most 1.5.

In a preferred embodiment of the invention, all optical high-refractive-index and low-refractive-index layers of the band-stop filter are constructed as dielectric layers. At this time, the thin layer coating forms a so-called dielectric superlattice (superlattice). A dielectric superlattice may also be physically understood as a bragg mirror.

For optically high refractive index dielectric layers, the above materials are particularly contemplated. For reasons of cost and depositability, silicon nitride, silicon-metal mixed nitrides (in particular zirconium silicon nitride) and titanium oxide are preferred, with silicon nitride being particularly preferred.

The optical thickness of the individual layers depends inter alia on the desired spectral position of the blocking range, which in turn depends on the emission wavelength of the electroluminescent arrangement at the incidence. The optical thickness of the optical high refractive index layer is preferably 10 nm to 30 nm. These optical thicknesses can be achieved, for example, with a silicon nitride-based high refractive index layer (refractive index 2.04) having a geometric thickness of about 5 nm to 15 nm.

For optically low-refractive-index dielectric layers, the above-mentioned materials are particularly conceivable. Silicon oxide is preferred. The optical thickness of the optical low refractive index layer is preferably 150 nm to 400 nm. These optical thicknesses can be achieved, for example, with a silicon oxide-based low refractive index layer (refractive index 1.47) having a geometric thickness of about 100 nm to 270 nm.

The superlattice comprises n optically high refractive index layers and n optically low refractive index layers, where n is a natural number greater than or equal to 1. Preferably, the superlattice is composed of (n +1) optically high refractive index layers and n optically low refractive index layers such that the uppermost and lowermost layers are optically high refractive index layers. However, in principle also structures are possible here which are formed from n optically high refractive index layers and n optically low refractive index layers or from n optically high refractive index layers and (n +1) optically low refractive index layers. Preferably, n is at least 5, particularly preferably at least 10, very particularly preferably at least 15. Thus, advantageous and suitable optical properties can be achieved. Preferably, n is from 5 to 50, very particularly preferably from 10 to 30, in particular from 15 to 25. These regions constitute, on the one hand, a good compromise with respect to the optical performance of the band-stop filter and, on the other hand, a layer structure which is as simple as possible. Preferably no further layers are present.

In a further preferred embodiment of the invention, at least some of the optical low refractive index layers of the band stop filter are configured as electrically conductive layers. The optically high refractive index layer and the remaining optically low refractive index layer (if present) are configured as dielectric layers. The thin layer coating then forms a so-called fabry-perot interferometer. Here, interference effects also occur after the transmitted radiation has been reflected at the interfaces, in particular the highly reflective conductive layers, and the filter effect is attributed to these interference effects. A band-stop filter of the fabry-perot interferometer type has the advantage over band-stop filters of the dielectric superlattice type that comparable optical performance can be achieved with a smaller number of single layers. Furthermore, in addition to the main blocking range, another blocking range can also be produced in the visible spectrum, for example in the Infrared (IR) range, so that the band-stop filter simultaneously acts as a sun protection coating (IR-reflective coating). A disadvantage of fabry-perot interferometers compared to dielectric superlattices is the fact that many conductive layers, for example silver layers, are susceptible to corrosion. In this case, the use of fabry-perot interferometers on the outer surface of the inner or outer glass pane facing away from the intermediate layer is to be avoided. Furthermore, the fabry-perot external interferometer reduces the total light transmission more significantly than the superlattice due to absorption by the conductive layer.

The electrically conductive layer may be a metal-containing layer, for example a layer based on silver (Ag), gold, copper, aluminum, or a layer based on a Transparent Conductive Oxide (TCO), for example indium tin oxide (ITO, indium tin oxide). The conductive layer is preferably made on the basis of silver. The conductive layer preferably contains at least 90% by weight of silver, particularly preferably at least 99% by weight of silver, very particularly preferably at least 99.9% by weight of silver. Particularly good results are thereby achieved. The silver layer preferably has a geometric thickness of 2 nm to 10 nm. There is sufficient reflection performance in this range to ensure the interference effect, so that it is not necessary to design it thicker.

In principle, all low-refractive-index layers can be designed as electrically conductive layers, with optically high-refractive-index dielectric layers being arranged between adjacent electrically conductive layers. Preferably, however, only a part of the low-refractive-index layers is designed as a conductive layer, while the remaining low-refractive-index layers are designed as dielectric layers. A regular structure is particularly preferred here, so that the same number of dielectric layers is arranged between all adjacent conductive layers in each case. Thus, for example, every second low refractive index layer can be designed as a conductive layer, so that a dielectric low refractive index layer and two dielectric high refractive index layers are each arranged between adjacent conductive layers.

For the dielectric layer, the above-mentioned materials are particularly considered. Silicon nitride, silicon-metal mixed nitrides (in particular zirconium silicon nitride) and titanium oxide are particularly preferred for the high refractive index layer and silicon oxide for the low refractive index layer because of the depositability. Particularly good antireflection of the conductive layer is achieved with titanium oxide.

The Fabry-Perot optical interferometer comprises n optical high-refractive-index layers and n optical low-refractive-index layers, wherein n is a natural number greater than or equal to 1. The fabry-perot optical interferometer is preferably composed of (n +1) optical high refractive index layers and n optical low refractive index layers, such that the uppermost and lowermost layers are optical high refractive index layers. Preferably, n is at least 3, particularly preferably at least 5, very particularly preferably at least 7. Thus, advantageous and suitable optical properties can be achieved. Preferably, n is from 3 to 20, very particularly preferably from 5 to 15, in particular from 7 to 12. These regions constitute, on the one hand, a good compromise with respect to the optical performance of the band-stop filter and, on the other hand, a layer structure which is as simple as possible with a high light transmission. Preferably no further layers are present.

In other words, the fabry-perot optical interferometer comprises a plurality of electrically conductive layers, in particular silver-based electrically conductive layers, wherein a dielectric layer or a sequence of dielectric layers is arranged between adjacent electrically conductive layers and above an uppermost electrically conductive layer and below a lowermost electrically conductive layer, respectively. The dielectric layer sequence is composed of m optical low-refractive-index layers and (m +1) optical high-refractive-index layers, which are arranged alternately such that an optical low-refractive-index layer is arranged between two adjacent high-refractive-index layers, respectively. The number m is a natural number greater than or equal to 1. The dielectric monolayer between adjacent conductive layers, above the uppermost conductive layer, or below the lowermost conductive layer is preferably an optically high index of refraction layer. The number m may be chosen independently for each dielectric layer sequence, but is preferably the same for all layer sequences. Particularly preferably, m is equal to 1. Between all adjacent conductive layers, a dielectric layer sequence is preferably arranged in each case. The number of conductive layers is preferably at least 3, particularly preferably from 3 to 7.

In the embodiment of a band stop filter according to the fabry-perot interferometer type, the optical thickness of the single layer of dielectric depends inter alia on the desired spectral position of the blocking range, which in turn depends on the emission wavelength of the electroluminescent arrangement at the incidence. The optical thickness of the optical high refractive index layer is preferably 30 nm to 300 nm. These optical thicknesses can be achieved, for example, with a titanium oxide-based high-refractive-index layer having a geometric thickness of about 10 nm to 100 nm (refractive index 2.8) or with a silicon nitride-based high-refractive-index layer having a geometric thickness of about 15 nm to 150 nm (refractive index 2.04). The optical thickness of the dielectric optical low refractive index layer is preferably 150 nm to 400 nm. These optical thicknesses can be achieved, for example, with a silicon oxide-based low refractive index layer (refractive index 1.47) having a geometric thickness of about 100 nm to 270 nm.

If the first layer is arranged above the second layer, this means in the sense of the present invention that the first layer is arranged further away from the substrate on which the coating is applied than the second layer. If the layer is formed from a material, the layer is mostly formed from this material, apart from possible impurities or dopants.

In a particularly preferred embodiment, the electroluminescent device is designed as an electroluminescent film which is arranged between the outer pane of glass and the inner pane of glass. The arrangement between the outer glass pane and the inner glass pane includes the case where the electroluminescent device is arranged directly on one of the mutually facing surfaces of the outer glass pane or the inner glass pane. The electroluminescent film is preferably embedded in the thermoplastic intermediate layer and is arranged there between two layers of thermoplastic joining material, thereby ensuring a stable joining of the electroluminescent film to the two glass panes. The optical band stop filter is arranged on the inner space side with respect to the electroluminescent film, in particular on the outer side surface of the inner glass pane, on the inner space side surface of the inner glass pane or between the electroluminescent film and the inner glass pane within an intermediate layer. The radiation direction of the electroluminescent arrangement provided is directed towards the outside environment, whereas radiation passing through the inner glass pane into the interior space of the vehicle is blocked by means of the band-stop filter. Such vehicle glazing is used as a so-called "privacy" glazing, in which the transmission from the outside into the interior space of the vehicle is prevented or at least hindered by irradiation by an electroluminescent film as a surface light source. In this embodiment, the vehicle glass is particularly preferably a vehicle roof glass panel.

In a further particularly preferred embodiment, the electroluminescent device is designed as an electroluminescent film which is arranged between the outer glass pane and the inner glass pane. The electroluminescent film is preferably arranged on the outer side surface of the inner glass pane or embedded in the thermoplastic interlayer. The optical band stop filter is arranged on the outside with respect to the electroluminescent film, in particular on the outside surface of the outer glass pane, on the side surface of the interior space of the outer glass pane or between the electroluminescent device and the outer glass pane within an intermediate layer. The provided radiation direction of the electroluminescent arrangement is directed into the interior space of the vehicle, while radiation through the outer glass pane into the external environment is prevented by the band-stop filter. Electroluminescent devices can be used as display elements (displays) in such vehicle panes, in particular for displaying information for the driver (for example in accordance with the type of head-up display). In such an embodiment, the vehicle glazing is particularly preferably a windscreen. Instead of an electroluminescent film, such a display element can also be formed from a plurality of light-emitting diodes, in particular of light-emitting diodes of the same color. However, the electroluminescent device can also be used as a surface light source for illuminating the interior space of the vehicle-the vehicle glazing is particularly preferred here as a vehicle roof glazing.

In a further particularly preferred embodiment, the electroluminescent device comprises a plurality of light-emitting diodes which are arranged on the (flat) interior-space-side surface of the inner glass pane or in the recesses of the interior-space-side surface of the inner glass pane. The main emission direction of the light-emitting diode opposite the electrical contact points is directed towards the vehicle interior space. The inner-space-side surface of the inner glass pane is preferably provided with an electrically conductive coating which is structured, in particular by insulating lines, and ensures electrical contact with the light-emitting diode. The light-emitting diodes are reliably fixed on or in the surface of the glass plate, for example by using an adhesive or by soldering with an electrically conductive coating. The optical band-stop filter is arranged on the outside with respect to the light-emitting diode, in particular on the outside surface of the outer glass pane, on the inner-space-side surface of the outer glass pane, in the intermediate layer or on the outside surface of the inner glass pane. The provided radiation direction of the electroluminescent arrangement is directed into the interior space of the vehicle, while radiation through the outer glass pane into the external environment is prevented by the band-stop filter. In such vehicle glazing, the electroluminescent device may be used to illuminate the vehicle interior space. In such an embodiment, the vehicle glazing is particularly preferably a vehicle roof glazing.

In a further particularly preferred embodiment, the electroluminescent arrangement comprises a plurality of light-emitting diodes which are arranged on the (flat) interior-space-side surface of the outer glass pane or in indentations in the interior-space-side surface of the outer glass pane. The main emission direction of the light-emitting diode opposite the electrical contact points is directed towards the vehicle interior space. The inner-space-side surface of the outer glass pane is preferably provided with an electrically conductive coating which is structured, in particular by insulating lines, and ensures electrical contact with the light-emitting diode. The light-emitting diodes are reliably fixed on or in the surface of the glass plate, for example by using an adhesive or by soldering with an electrically conductive coating. The optical band-stop filter is arranged on the outside with respect to the light-emitting diode, in particular on the outside surface of the outer glass plate. The provided radiation direction of the electroluminescent arrangement is directed into the interior space of the vehicle, while radiation through the outer glass pane into the external environment is prevented by the band-stop filter. In such vehicle glazing, the electroluminescent device may be used to illuminate the vehicle interior space. In such an embodiment, the vehicle glazing is particularly preferably a vehicle roof glazing.

In a further particularly preferred embodiment, the electroluminescent arrangement comprises a plurality of light-emitting diodes which are arranged between the outer glass pane and the inner glass pane. The main emission direction of the light-emitting diode opposite the electrical contact points is directed towards the vehicle interior space. The optical band-stop filter is arranged on the outer side with respect to the light emitting diode. The provided radiation direction of the electroluminescent arrangement is directed into the interior space of the vehicle, while radiation through the outer glass pane into the external environment is prevented by the band-stop filter. Electroluminescent devices may also be used in such vehicle glazing panels to illuminate the vehicle interior space. In such an embodiment, the vehicle glazing is particularly preferably a vehicle roof glazing. In detail, the electroluminescent device may be arranged:

-on the outer side surface of the inner glass pane or in a gap of the outer side surface, wherein a band-pass filter is arranged in the intermediate layer or on one of the surfaces of the outer glass pane;

in an intermediate layer, for example on a carrier film, wherein a band-pass filter is arranged in the intermediate layer between the electroluminescent device and the outer glass pane; or

-on or in a gap in an inner space side surface of the outer glass plate, wherein the band-pass filter is arranged on an outer side surface of the outer glass plate.

The electrical contacting of the light-emitting diodes is in turn effected, for example, by structured electrically conductive coatings on the respective glass pane surfaces or carrier films.

In common to the three particularly preferred embodiments described above, the electroluminescent device is designed as a plurality of light-emitting diodes and serves to illuminate the interior of the vehicle. The light-emitting diodes are arranged on or in the recesses of the inner-space-side surface of the outer glass pane, on or in the recesses of the inner-space-side surface of the inner glass pane, on the outer-side surface of the inner glass pane or in the intermediate layer. The optical band-stop filter is arranged on the outside with respect to the electroluminescent arrangement. The vehicle glazing is preferably a vehicle roof glazing. In this embodiment, the light-emitting diodes can also be replaced by light-scattering structures on the surface of the glass plate, in the glass plate or in the intermediate layer, which are illuminated by a light source arranged on the side edges of the glass plate or of the intermediate layer. The light-scattering structures can be produced, for example, by screen printing on the surface of the glass plate or on the carrier film, by producing roughened regions of the surface of the glass plate by means of mechanical or laser machining, or by laser machining within the glass plate.

The outer and inner glass panes are preferably made of glass, in particular soda-lime glass, as is common for window panes. However, these glass plates can in principle 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 and inner glass sheets can vary widely. Preference is given to using glass plates having a thickness of from 0.8 mm to 5 mm, preferably from 1.4 mm to 2.5 mm, for example glass plates having a standard thickness of 1.6 mm or 2.1 mm.

The thermoplastic interlayer comprises at least one layer of a thermoplastic bonding material, preferably comprising Ethylene Vinyl Acetate (EVA), polyvinyl butyral (PVB) or Polyurethane (PU) or mixtures or copolymers or derivatives thereof, particularly preferably PVB. The intermediate layer is typically formed from at least one thermoplastic film. The thickness of the film is preferably from 0.3 mm to 2 mm, standard thicknesses of 0.36 mm and 0.76 mm being particularly customary.

The outer glass sheet, inner glass sheet and thermoplastic interlayer may be clear and colorless, but may also be tinted or colored. The outer and inner glass sheets may be unstressed, partially prestressed or prestressed independently of each other. If at least one of the glass sheets should be prestressed, this can be thermally or chemically prestressed.

The vehicle glazing is preferably curved in one or more directions in space, as is common for automotive vehicle glazing, with a typical radius of curvature of about 10 cm to about 40 m. However, the vehicle glazing may also be flat, for example when it is provided as a glazing for a bus, train or tractor.

The vehicle glazing may be manufactured by methods known per se. The outer and inner glass sheets are laminated to each other by an interlayer, for example, by autoclave, vacuum bag, vacuum ring, calendering, vacuum laminator, or combinations thereof. The joining of the outer glass pane and the inner glass pane is usually carried out here under the influence of heat, vacuum and/or pressure. If the vehicle glass sheets are curved, the individual glass sheets are subjected to a bending process, such as bending by gravity, press bending and/or suction bending, prior to lamination. Preferably, the outer glass pane and the inner glass pane are congruent-curved overlapping one another jointly (i.e. simultaneously and by the same tool), since the shapes of these glass panes are thereby matched to one another optimally for the later-on lamination. Typical temperatures for the glass bending process are, for example, 500 ℃ to 700 ℃. This temperature treatment also increases the transparency and reduces the sheet resistance of the reflective coating.

The thin layer of the band stop filter is preferably applied to the surface of the glass plate by physical vapor deposition (PVD, physical vapor deposition), particularly preferably by cathode sputtering ("sputtering"), very particularly preferably by magnetic field-assisted cathode sputtering ("magnetron sputtering"). However, other thin-layer processes, such as Chemical Vapor Deposition (CVD), Atomic Layer Deposition (ALD), evaporation or holographic processes, can also be used. In particular, dielectric superlattices on a carrier film are also commercially available. The coating is preferably applied to one of the glass sheets before lamination and before a possible bending process. Instead of applying a reflective coating to the surface of the glass pane, it is in principle also possible to provide this reflective coating on a carrier film, which is arranged in an intermediate layer. However, the band stop filter on the outer surface (outer side surface of the outer glass plate, inner space side surface of the inner glass) may in principle also be applied after lamination.

The electroluminescent device is arranged on one of the glass pane surfaces or is inserted into the intermediate layer. If the light-emitting diodes are to be introduced into the recesses in the surface of the glass plate, these recesses are produced by drilling, for example by means of laser machining or mechanical means. The mounting of the electroluminescent arrangement on the outer surface is preferably carried out after lamination, on the outer surface, or within an intermediate layer, necessarily before lamination.

Furthermore, the invention comprises the use of a vehicle glazing according to the invention as a window glazing of a vehicle. Furthermore, the invention also includes a vehicle equipped with a vehicle glazing according to the invention. The vehicle may be any land, water or air vehicle, preferably a passenger car, truck or rail vehicle.

The invention is explained in detail below with the aid of figures and examples. The figures are schematic and not to scale. The drawings are not intended to limit the invention in any way.

Wherein:

figure 1 shows a cross section through a first embodiment of a vehicle glazing according to the invention,

figure 2 shows a cross section through a second embodiment of a vehicle glazing according to the invention,

figure 3 shows a cross section through a third embodiment of a vehicle glazing according to the invention,

figure 4 shows a cross section through a fourth embodiment of a vehicle glazing according to the invention,

figure 5 shows a cross section through an inner glass plate with a dielectric superlattice as a band stop filter (not claimed per se),

figure 6 shows a cross section through an inner glass plate with a fabry-perot interferometer (not claimed per se) as a band stop filter,

figure 7 shows a schematic transmission spectrum of a band stop filter,

figure 8 shows the transmission spectra of examples 1-3 of the invention,

FIG. 9 shows transmission spectra of examples 1, 4 and 5 of the present invention, and

fig. 10 shows the transmission spectrum of example 6 of the present invention.

FIG. 1 illustrates one embodiment of a vehicle glazing panel according to the present invention. The vehicle glass panel is a composite glass panel which structurally consists of an outer glass panel 1 and an inner glass panel 2 which are joined to one another by a thermoplastic interlayer 3. The outer glass pane 1 faces the outside environment in the mounted position and the inner glass pane 2 faces the vehicle interior space. The outer glass pane 1 has an outer side surface I, which in the mounted position faces the outside environment, and an inner space side surface II, which in the mounted position faces the inner space. Likewise, the inner glass pane 2 has an outer side surface III, which in the mounted position faces the outside environment, and an inner space side surface IV, which in the mounted position faces the inner space. The inner space-side surface II of the outer glass pane 1 and the outer side surface III of the inner glass pane 2 face each other and are joined to each other by means of a thermoplastic interlayer 3.

The vehicle glazing is configured as a roof glazing of a passenger car. The glass plate is manufactured as a so-called privacy roof glass plate in which the transmission from the outside can be prevented by a surface light source radiating outward. The light source is an electroluminescent film 20 embedded in the intermediate layer 3. For this purpose, an electroluminescent film 20 is arranged between the first layer of thermoplastic bonding material 3a and the second layer of thermoplastic bonding material 3 b. The electroluminescent film 20 is bonded to the outer glass pane 1 by a first layer of thermoplastic bonding material 3a and to the inner glass pane 2 by a second layer of thermoplastic bonding material 3 b.

The outer glass plate 1 and the inner glass plate 2 are made of soda lime glass, for example. The outer glass plate 1 has, for example, a thickness of 2.1 mm and the inner glass plate 2 has a thickness of 2.1 mm or 1.6 mm. Both layers of thermoplastic bonding material 3a, 3b were manufactured as PVB-based films with a thickness of 0.76 mm.

The electroluminescent film 20 comprises an active layer of electroluminescent material of the LED or OLED type arranged between two carrier films. The carrier film is, for example, a PET film having a thickness of 50 μm. Between each carrier film and active layer, a respective electrically conductive coating is arranged as an electrode, electrical contact and can be connected to the vehicle electronics. The active layer may be stimulated to emit light by applying a voltage across the electrodes, thereby activating the light source. The electroluminescent film 20 emits radiation in the visible spectral range (380 nm to 780 nm). Depending on the embodiment of the active layer, different colors of radiation can be achieved. In particular, electroluminescent films 20 having the standard colors red (630 nm), green (550 nm) or blue (473 nm) are common. White or near-white electroluminescent radiation can also be achieved by superposition of different colors or by very broad-band luminescent emission.

In addition to the desired direction of radiation through the outer pane 1 to the environment outside the vehicle, the electroluminescent film 20 also emits radiation in the direction of the inner pane 2. This can reach into the vehicle interior and is sometimes perceived as disturbing there. In order to prevent radiation through the inner glass pane 2 into the vehicle interior space, the outer side surface III of the inner glass pane 2 is provided with a thin-layer coating, which acts as an optical band-stop filter. By suitable design of the layer structure of the coating, the band-stop filter is matched to the emission spectrum of the electroluminescent film 20, so that it substantially blocks radiation. Thus, the radiation of the electroluminescent film 20 cannot or can only enter the vehicle interior space with a significantly reduced intensity.

A band-reject filter is an interference filter formed by thin layers. It can be designed in particular as a so-called dielectric superlattice 40 or as a so-called fabry-perot interferometer 50.

The dielectric superlattice 40 is formed purely of dielectric single layers in which optically high refractive index layers 41 having a refractive index greater than 1.8 and optically low refractive index layers 42 having a refractive index less than 1.8 are alternately stacked on top of each other. Table 1 shows an exemplary structure of the vehicle glazing in fig. 1 with a dielectric superlattice 40 as a band stop filter, wherein the materials and layer thicknesses according to three inventive examples 1-3 are given. The superlattice 40 comprises 21 pieces of aluminum-doped silicon nitride (Si) respectively₃N₄) A high refractive index layer and 20 aluminum-doped silicon oxide (SiO)₂) The layers are produced. By selecting the layer thicknesses of the

dielectric layers

41, 42, the optical performance of the band stop filter can be adjusted and matched to the requirements in the specific application case.

Table 2 shows an exemplary structure of the vehicle glazing in fig. 1 with the dielectric superlattice 40 as a band-stop filter, wherein the materials and layer thicknesses according to two further inventive examples 4-5 are given.

The fabry-perot interferometer 50 is likewise formed from alternating thin optically high-refractive-index and low-refractive-index layers, wherein at least a part of the optically low-refractive-index layers is formed as a conductive layer 53, while the optically high-refractive-index layer 51 and the remaining optically low-refractive-index layers 52 are formed as dielectric layers. Table 3 shows an exemplary structure of the vehicle glazing of fig. 1 with a fabry-perot interferometer 50 as a band-stop filter, wherein the materials and layer thicknesses according to another inventive embodiment 6 are given. The conductive layer 53 is formed based on silver (Ag) and serves, inter alia, as a partially transparent mirror. The high index dielectric layer 51 is formed of aluminum-doped silicon nitride (Si)₃N₄) And the low index dielectric layer 52 is formed of aluminum doped silicon oxide (SiO)₂) And (4) forming. By selecting the layer thicknesses of the

dielectric layers

51, 52, the optical path length between the conductive layers 53 is adjusted, whereby the optical performance of the band stop filter can be matched to the requirements in the specific application case.

The band stop filters 40, 50 may alternatively also be applied on the inner space side surface IV of the inner glass pane 2. However, it is exposed to a greater extent to external influences there, so that this arrangement is less preferred. The band-

stop filters

40, 50 may alternatively also be embedded on the carrier film between the device 20 in the intermediate layer 3 and the inner glass pane 2. However, this would make the structure of the intermediate layer 3 more complicated, and therefore this arrangement is less preferred.

In this figure, the band stop filters 40, 50 are applied over the entire surface of the surface III of the inner glass pane 2. Alternatively, however, the surface III may also have an uncoated peripheral edge region to prevent the band-

stop filters

40, 50 from coming into contact with the surrounding atmosphere. It is particularly advantageous if the band stop filter is constructed as a fabry-perot interferometer 50 on account of a silver layer which is susceptible to corrosion. Since the vehicle glazing is mostly provided with an opaque cover print in the edge region, there is also no need for the band stop filters 40, 50 to suppress the emission of light.

Figure 2 shows another embodiment of a vehicle glass pane according to the invention having an outer glass pane 1, an inner glass pane 2 and a thermoplastic interlayer 3. The vehicle glazing is configured as a windscreen panel of a passenger car. The interlayer 3 was formed from a single PVB film having a thickness of 0.76 mm. In the lower region of the vehicle glazing, an electroluminescent film 20 is arranged on the outer side surface III of the inner glazing 2 and is fixed thereto, for example by a thin adhesive layer. The electroluminescent film 20 is arranged for radiation through the inner glass pane 2 into the vehicle interior space for use as a display element for the driver. Thus, for example, when the in-vehicle electronic device activates the electroluminescent film 20 according to the sensor signal, static information can be displayed. Furthermore, a symbol can be displayed, which is produced by the shape of the electroluminescent film 20 or by a masking region (for example an opaque cover print on one of the surfaces III, IV of the inner pane 2). Alternatively, the electrodes of the electroluminescent film 20 can also be structured in such a way that the electroluminescent film 20 can be controlled "pixel by pixel" in order to display dynamic information.

In this case, the desired radiation direction of the electroluminescent film 20 is directed towards the vehicle interior space, while radiation through the outer pane 1 to the outside environment should be prevented. For this purpose, the inner-space-side surface II of the outer glass plate 1 is equipped with a band-stop filter, which in turn can be designed as a dielectric superlattice 40 or as a fabry-perot interferometer 50, as described in connection with fig. 1.

The band stop filters 40, 50 may alternatively also be arranged on the outer side surface I of the outer glass pane 1 or in an intermediate layer.

Figure 3 shows another embodiment of a vehicle panel according to the invention having an outer glass sheet 1, an inner glass sheet 2 and a thermoplastic interlayer 3 formed from a single PVB film having a thickness of 0.76 mm.

The vehicle glazing is provided as a roof glazing of a passenger car and is intended to provide a lighting function for the interior of the car. For this purpose, the vehicle glazing is equipped with a plurality of light-emitting diodes 30. The inner space side surface II of the outer glass plate is provided with bores which form indentations for the light-emitting diodes 30. The inner space side surface II is provided with a conductive coating which acts as an electrode layer 31 for the light emitting diode 30. The electrode layer 31 is structured by insulating wires to ensure electrical feed lines to the individual light emitting diodes 30. The light-emitting diode 30 is then inserted into the recess in the side surface II of the interior and is electrically conductively connected to the electrode layer.

In this case, the desired radiation direction of the light-emitting diode 30 is directed towards the vehicle interior space, whereas radiation through the outer glass pane 1 to the outside environment should be prevented. For this purpose, the outer side surface I of the outer glass plate 1 is equipped with a band-stop filter, which in turn can be constructed as a dielectric superlattice 40 or as a fabry-perot interferometer 50, as described in connection with fig. 1.

Figure 4 shows another embodiment of a vehicle glass pane according to the invention having an outer glass pane 1, an inner glass pane 2 and a thermoplastic interlayer 3. The vehicle glazing is an alternative embodiment of the roof glazing with illumination of figure 3. The light emitting diode 30 is fitted into a notch in the inner space side surface IV of the inner glass plate 2. The band stop filters 40, 50 are arranged on the outer side surface III of the inner glass pane 2.

The band stop filters 40, 50 can likewise be applied well on the inner-space-side surface II of the outer glass pane 1. The band stop filters 40, 50 may also be arranged on the outer side surface I of the outer glass sheet 1 or within the intermediate layer 3, although this is less preferred.

Fig. 5 shows a schematic structure of a band stop filter according to the type of dielectric superlattice 40 on the inner glass plate 2. The superlattice 40 is designed as in tables 1 and 2.

Fig. 6 shows a schematic structure of a band-stop filter according to the fabry-perot interferometer 50 type on the inner glass plate 2. The fabry-perot interferometer 50 is designed as in table 3.

Fig. 7 schematically shows the transmission spectrum of the band-stop filter in the visible spectral range. The band-stop filter has a blocking range of low transmission, while there is high transmission outside the blocking range. Thus, the band-stop filter can block radiation in the blocking range. The blocking range of the spectral laser (Lase) is characterized by a central wavelength λ₀(center point of blocking range) and half-value width Δ λ (defined by the wavelength at which 50% of the blocking depth Δ T is reached). Since the band-stop filter is due to interference effects, the transmission spectrum adjacent to the blocking range is not perfectly smooth, but has an oscillating shape. Transmittance value T occurring at a local transmittance maximum adjacent to the blocking range_{Maximum of}And a minimum transmittance value (minimum transmittance T) in the blocking range_{Minimum size}) The difference between is the barrier depth Δ T. Minimum transmittance T_{Minimum size}Is a measure of the quality of the band-stop filter-the minimum transmission T_{Minimum size}The smaller the less radiation that is transmitted by the band stop filter. The slope illustrates in which spectral range the transmittance at the edge of the blocking range rises to the maximum transmittance.

The performance of the band stop filter can be tuned by the design of the thin layer system. The optical thickness of the individual layers is in particular centered at the center wavelength λ₀And half-value width DeltaLambda, while barrier depth DeltaT, minimum transmittance T_{Minimum size}And the slope can be influenced in particular by the number of layers.

FIG. 8 shows the transmission spectra (incident angle 0 ℃ C.) of the glass sheets for vehicles according to examples 1 to 3 of the present invention, whose layer structures are shown in Table 1. A band-stop filter is formed by each superlattice 40, wherein the band-stop filters differ in their spectral positions. The band-stop filter of example 1 was tuned to blue radiation near 450 nm, the band-stop filter of example 2 was tuned to green near 550 nm, and the band-stop filter of example 3 was tuned to red near 560 nm.

Fig. 9 shows the transmission spectra (incident angle 0 °) of the vehicle glass plates according to inventive example 1 and inventive examples 5 and 6, the layer structures of which are shown in table 2. By passingEach superlattice 40 forms a band-stop filter, with the center wavelength λ of the illustrated embodiment₀The same is true. However, they differ significantly in their bandwidth Δ λ and their blocking depth Δ T.

It is evident from the examples that the optical properties can be adjusted very precisely by the design of the thin-layer coating. The band stop filter can thus be easily formed individually according to the requirements in the application situation.

Fig. 10 shows the transmission spectrum (incident angle 0 °) of the vehicle glass plate according to example 6 of the present invention, and the layer structure thereof is shown in table 3. By means of the fabry-perot interferometer 50, a band stop filter is formed having a blocking range in the blue spectral range around 400 nm. An advantage of the fabry-perot interferometer 50 is that it can form an additional blocking range (or a range of reduced transmission), as seen in the red range around 700 nm in the present case. Thus, the band-stop filter may simultaneously serve as an IR protective coating, for example.

List of reference numerals:

(1) outer glass plate

(2) Inner glass plate

(3) Thermoplastic interlayer

(3a) First layer of thermoplastic bonding material

(3b) Second layer of thermoplastic bonding material

(20) An electroluminescent device: electroluminescent film

(30) An electroluminescent device: light emitting diode

(31) Electrode layer of light emitting diode 30

(40) Band elimination filter: dielectric superlattice

(41) Optical high index layer of dielectric superlattice 40

(42) Optically low refractive index layer of dielectric superlattice 40

(50) Band elimination filter: Fabry-Perot interferometer

(51) Optical high index layer for fabry-perot interferometer 50

(52) Optically low index layer for fabry-perot interferometer 50

(53) Conductive layer of Fabry-Perot interferometer 50

λ₀Center wavelength of band-stop filter

Half-value width of delta lambda band-stop filter

Blocking depth of delta-T band stop filter

T_{Minimum size}Minimum transmission of band stop filter

T_{Maximum of}Transmittance value at local transmittance maximum adjacent to blocking range

(I) Outer side surface of the outer glass plate 1

(II) side surface of inner space of outer glass plate 1

(III) outer side surface of the inner glass plate 2

(IV) the inner space side surface of the inner glass plate 2.

Claims

1. Vehicle glass pane made of an outer glass pane (1) having an outer side surface (I) and an inner space side surface (II) and an inner glass pane (2) having an outer side surface (III) and an inner space side surface (IV), wherein the inner space side surface (II) of the outer glass pane (1) and the outer side surface (III) of the inner glass pane (2) are joined to one another by means of a thermoplastic interlayer (3),

the vehicle glazing is equipped with an electroluminescent device (20, 30) and an optical band-stop filter (40, 50) having a blocking range,

wherein

-the optical band-stop filter (40, 50) is configured as a thin-layer coating made of alternating layers of optically high refractive index with a refractive index greater than 1.8 and optically low refractive index with a refractive index less than 1.8,

-the mean wavelength of the radiation emitted by the electroluminescent arrangement (20, 30) lies within the blocking range of the optical band-stop filter (40, 50),

-the optical band-stop filter (40, 50) is arranged such that radiation of the electroluminescent device (20, 30) through the outer glass plate (1) or through the inner glass plate (2) is blocked and

-the half-value width (Δ λ) of the blocking range of the band-stop filter (40, 50) is 10 nm to 50 nm.

2. Vehicle glazing according to claim 1, wherein the optical band stop filter is constructed as a dielectric superlattice (40), wherein all optical high refractive index layers (41) and all optical low refractive index layers (42) are dielectric layers.

3. The vehicle glazing of claim 2, wherein the optical thickness of the optical high index layer (41) is from 10 nm to 30 nm, the optical thickness of the optical low index layer (42) is from 150 nm to 400 nm, and the thin layer coating comprises at least five optical high index layers (41) and at least five optical low index layers (42).

4. Vehicle glazing according to claim 2 or 3, wherein the optically high refractive index layer (41) is composed on the basis of silicon nitride, silicon-metal mixed nitride or titanium oxide, and the optically low refractive index layer (42) is composed on the basis of silicon oxide.

5. The vehicle glazing of claim 1, wherein the optical band-stop filter is configured as a fabry-perot interferometer (50), wherein at least some of the optical low index layers are electrically conductive layers (53) and all optical high index layers (41) are dielectric layers.

6. Vehicle glazing according to claim 5, wherein between adjacent conductive layers (53) there is respectively arranged a dielectric layer sequence made of (m +1) optically high refractive index layers (51) and m optically low refractive index layers (52), where m is a natural number greater than or equal to 1.

7. Vehicle glazing according to claim 5 or 6, wherein the optical thickness of the optical high refractive index layer (51) is from 30 nm to 300 nm, the optical thickness of the dielectric optical low refractive index layer (52) is from 150 nm to 400 nm, and the number of electrically conductive layers is at least 3.

8. Vehicle glazing according to any of claims 5 to 7, wherein the optically high refractive index layer (51) is composed on the basis of silicon nitride, silicon-metal mixed nitride or titanium oxide, the optically low refractive index layer (52) is composed on the basis of silicon oxide and the electrically conductive layer (53) is composed on the basis of silver.

9. Vehicle glazing according to any of claims 1 to 8, wherein half of the half-value width of the radiation of the electroluminescent device (20, 30) is equal to the central wavelength (λ) of the band-stop filter (40, 50)₀) And the mean wavelength of the radiation of the electroluminescent arrangement (20, 30) is less than half the half-value width (Delta lambda) of the band-stop filter (40, 50).

10. The vehicle glazing of any of claims 1 to 9, wherein the electroluminescent device is configured as an electroluminescent film (20) arranged between the outer glazing pane (1) and the inner glazing pane (2), and wherein the optical band-stop filter (40, 50) is arranged on an outer side surface (III) of the inner glazing pane (2), on an inner space side surface (IV) of the inner glazing pane (2) or within an intermediate layer (3) between the electroluminescent film (20) and the inner glazing pane (1).

11. Vehicle glazing according to any of claims 1 to 9, wherein the electroluminescent device is configured as an electroluminescent film (20) arranged between the outer glazing pane (1) and the inner glazing pane (2), and wherein the optical band-stop filter (40, 50) is arranged on the outer side surface (I) of the outer glazing pane (1), on the inner space side surface (II) of the outer glazing pane (1) or within an intermediate layer (3) between the electroluminescent film (20) and the outer glazing pane (1).

12. Vehicle glazing according to any of the claims 1 to 9, wherein the electroluminescent device comprises a plurality of light emitting diodes (30) arranged on the inner space side surface (IV) of the inner glass pane (2) or in indentations of the inner space side surface (IV) of the inner glass pane (2), and wherein the optical band stop filter (40, 50) is arranged on the outer side surface (I) of the outer glass pane (1), on the inner space side surface (II) of the outer glass pane (1), within the intermediate layer (3) or on the outer side surface (III) of the inner glass pane (2).

13. Vehicle glazing according to any of claims 1 to 9, wherein the electroluminescent device comprises a plurality of light emitting diodes (30) arranged on the inner space side surface (II) of the outer glazing panel (1) or in indentations of the inner space side surface (II) of the outer glazing panel (1), and wherein the optical band stop filter (40, 50) is arranged on the outer side surface (I) of the outer glazing panel (1).

14. Vehicle glazing according to any of claims 1 to 9, wherein the electroluminescent device comprises a plurality of light emitting diodes (30) arranged between the outer glazing panel (1) and the inner glazing panel (2), and wherein the optical band stop filter (40, 50) is arranged on an outer side surface (I) of the outer glazing panel (1), on an inner space side surface (II) of the outer glazing panel (1) or within an interlayer (3) between the light emitting diodes (30) and the outer glazing panel (1).

15. A vehicle equipped with a vehicle glazing panel according to any of claims 1 to 14.