EP4337464A1

EP4337464A1 - Composite pane having heatable regions and intended for a projection assembly

Info

Publication number: EP4337464A1
Application number: EP22725255.8A
Authority: EP
Inventors: Andreas GOMER; Valentin SCHULZ; Bernd BOSCHKE
Original assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Current assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Priority date: 2021-05-12
Filing date: 2022-04-26
Publication date: 2024-03-20
Also published as: KR20230171460A; CN115623866A; WO2022238101A1

Abstract

The invention relates to a composite pane (1), in particular for a projection assembly (100), at least comprising: 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), wherein the outer pane (2) and the inner pane (3) each have an outer side (I, III) and an inner side (II, IV) and the inner side (II) of the outer pane (2) and the outer side (III) of the inner pane (3) are facing one another, and the thermoplastic intermediate layer (4) contains, or consists of, at least one masking layer (5) and the masking layer (5) is opaque at least in one region (5'); a heating element (6) arranged within the opaque region (5') of the masking layer (5); and a reflective layer (11) which is suitable for reflecting visible light (12), wherein the reflective layer (11) is arranged spatially in front of the masking layer (5) in the line of sight from the inner pane (3) to the outer pane (2) and overlaps at least partially with the opaque region (5') of the masking layer (5).

Description

1

Laminated pane that can be heated in certain areas for a projection arrangement

The invention relates to a composite pane that can be heated in certain areas for a projection arrangement, a method for its production, its use and a projection arrangement.

Head-up displays are commonly used in vehicles and airplanes these days. A head-up display works by using an imaging unit that uses an optics module and a projection surface to project an image that the driver perceives as a virtual image. If this image is reflected, for example, on the vehicle windshield as a projection surface, important information can be displayed for the user, which significantly improves road safety.

Vehicle windshields usually consist of two panes of glass which are laminated to one another via at least one thermoplastic film. In the case of head-up displays that are typically used, the problem arises that the projector image is reflected on both surfaces of the windshield. As a result, the driver not only perceives the desired main image, which is caused by the reflection on the interior surface of the windshield (primary reflection). The driver also perceives a slightly offset secondary image, which is usually of weaker intensity, which is caused by the reflection on the outside surface of the windshield (secondary reflection). This problem is commonly solved by arranging the reflective surfaces at a deliberate angle to each other so that the main image and sub-image are superimposed so that the sub-image is no longer distracting.

The head-up display projector radiation is typically essentially s-polarized due to the better reflection characteristics of the windshield compared to p-polarization. However, if the driver wears polarization-selective sunglasses that only transmit p-polarized light, he or she can hardly see the HUD image or not at all. There is therefore a need for HUD projection arrangements that are compatible with polarization-selective sunglasses. A solution to the problem in this context is therefore the use of projection arrangements which use p-polarized light. 2

Another problem is the perceptibility of the information transmitted via the reflected image, regardless of the weather and lighting conditions. Crucial and safety-relevant information must be able to be seen by the driver at any time of the day or night, in strong sunshine or rain. When designing a display that is based on head-up display technology, the projector must therefore have a correspondingly high output so that the projected image has sufficient brightness, especially in sunlight, and can be easily recognized by the viewer . This requires a certain size of the projector and is associated with a corresponding power consumption.

DE 102014220189A1 discloses a head-up display projection arrangement which is operated with p-polarized radiation in order to generate a head-up display image. Since the angle of incidence is typically close to Brewster's angle and p-polarized radiation is therefore reflected only to a small extent by the glass surfaces, the windshield has a reflective structure that can reflect p-polarized radiation in the direction of the driver. A single metallic layer with a thickness of 5 nm to 9 nm, for example made of silver or aluminum, is proposed as the reflective structure, which is applied to the outside of the inner pane facing away from the interior of the car.

US 2004/0135742 A1 also discloses a head-up display projection arrangement which is operated with p-polarized radiation in order to generate a head-up display image and has a reflecting structure which is p-polarized Radiation can reflect towards the driver. The multilayer polymer layers disclosed in WO 96/19347A3 are proposed as the reflective structure.

When designing a display that is based on head-up display technology, it must also be ensured that the projector has a correspondingly high output so that the projected image has sufficient brightness, especially when sunlight strikes it and easily recognizable by the viewer. This requires a certain size of the projector and is associated with a corresponding power consumption and heat dissipation. 3

It is possible to create a display also in the masking area, basically on the same principle as a HUD. The masking area is therefore also irradiated by a projector and reflected there, as a result of which a display is generated 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 that replaces the classic exterior mirrors or rear-view mirrors, can be displayed directly in a practical and aesthetically pleasing way displayed on the windscreen, for example in the portion of the masking area bordering the bottom edge of the windscreen. A projection arrangement of this type is known, for example, from DE 102009020824A1.

Another major challenge when driving is the heating of the windshield, in order to be able to prevent icing or fogging of the windshield, which impedes visibility. In particular, in the area near the lower edge of the windshield in the vehicle interior, water that has entered the vehicle interior due to penetrating moisture often condenses out. The pane is normally heated by means of heated air, which is blown onto the pane via inlets. This type of heating is summarized under 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 pane require a lot of space. Furthermore, the outlet nozzles have to be placed in a certain geometric relation to the disk, which in turn considerably restricts the freedom of design and construction.

Alternatively, the disc itself can have an electrical heating function. DE 10352464A1, for example, discloses a laminated glass pane in which electrically heatable wires are inserted between two glass panes. The specific heating power can be adjusted by the ohmic resistance of the wires. Due to design and safety aspects, the number and diameter of the wires must be kept as small as possible. The wires must be visually imperceptible or barely perceptible in daylight and at night when headlights are on. 4

The object of the present invention is therefore to provide an improved composite pane for projection arrangements which are based on HUD technology.

The object of the present invention is achieved according to the invention by a laminated pane according to claim 1 . Preferred embodiments emerge from the dependent claims.

According to the invention, a composite pane is described which is intended in particular for a projection arrangement. The laminated pane comprises at least: an outer pane, an inner pane and a thermoplastic intermediate layer arranged between the outer pane and the inner pane, a heating element and a reflection layer.

The outer pane and the inner pane each have an outside and an inside, and the inside of the outer pane and the outside of the inner pane face each other. The reflection layer is suitable for reflecting visible light. The thermoplastic intermediate layer contains or consists of at least one masking layer which is opaque at least in one area. The heating element is located within the opaque area of the masking layer. The reflection layer is arranged spatially in front of the masking layer in the viewing direction from the inner pane to the outer pane and at least partially overlaps with the opaque area of the masking layer.

By “the reflective layer is capable of reflecting visible light” it is meant that the reflective layer can reflect light to some extent visible light and is intended to reflect visible light of an image display device. The reflective layer preferably reflects at least 1% of the visible light impinging on it.

The reflection layer can be arranged on the inside or the outside of the inner pane. The reflective layer may have portions that are not in register with the opaque area of the masking layer. For the purposes of the invention, the “viewing direction from the inner pane to the outer pane” means the viewing direction in the orthogonal direction from the plane of the inner pane to the outer pane. 5

The laminated pane is intended to separate an interior space from an exterior environment. The inside of the inner pane faces the interior and the outside of the outer pane faces the outside environment.

The reflection layer overlaps partially or completely with the opaque region of the masking layer. For this reason, a good image representation with high contrast to the opaque area of the masking layer results, so that it appears bright and is therefore also excellently recognizable. This advantageously enables a reduction in performance of an image display device, which is intended to irradiate an imaging light onto the reflection layer. This results in reduced energy consumption and reduced heat generation. Arranging the heating element in the opaque area of the masking layer can be used to heat the laminated pane, which can reduce fogging (condensation on the inner pane or the outer pane) in the opaque area in general and the opaque area that overlaps with the reflective layer. As a result, the space in the dashboard area can be significantly reduced when installing the laminated pane as a vehicle pane in a vehicle. This leads to possibilities for a slimmer design in the vehicle interior. By means of the image representation via the reflective layer in front of the opaque area, the display with speedometer, engine speed indicator, warning indicator and fuel gauge, which is usually attached to the dashboard, can be replaced. The heating of the laminated pane by the heating element replaces supply lines, which usually direct air heated by engine heat to the windshield. If a current flows through the heating element, it is heated as a result of its electrical resistance and by means of Joule heat development. Furthermore, there are additional geometric degrees of freedom in the design of the vehicle interior if the air outlet nozzles, which are usually attached in a specific geometric relationship to the glazing, are omitted. The heating of the laminated pane using electrical energy is also more energy-efficient than heating using engine-heated air. The laminated pane according to the invention can be produced simply and inexpensively using known production methods.

Various preferred layer sequences of the laminated pane according to the invention are described below:

Outer pane - masking layer - reflective layer - inner pane 6

Outer pane - masking layer - inner pane - reflective layer

The laminated pane is intended to separate an interior space from an exterior environment. The inside of the inner pane faces the interior and the outside of the outer pane faces the outside environment. For the purposes of the invention, “the reflection layer is arranged spatially in front of the masking layer in the viewing direction from the inner pane to the outer pane” means that the reflection layer is spatially closer to the interior than the masking layer. The reflective layer is therefore spatially arranged in front of the masking layer when looking through the laminated pane from the interior. The laminated pane preferably has two opposite side edges and an upper edge and a lower edge. The upper edge is intended to be arranged in the installed position in the upper region, while the opposite lower edge is intended to be arranged in the installed position in the lower region. The total area of the composite pane results from the calculation of the surface area using the side edges, the top edge and the bottom edge. The size of the total area of the laminated pane is identical to the outside and the inside of the inner pane and the outer pane.

For the purposes of the present invention, "transparent" means that the total transmission of the composite pane meets the legal requirements for windshields (e.g. the European Union directives corresponds to ECE-R43) and for visible light preferably a transmittance (according to ISO 9050:2003) of more than 30% and in particular more than 60%, for example more than 70%. Correspondingly, "opaque" means a light transmission of less than 15%, preferably less than 10%, particularly preferably less than 5% and in particular 0%.

In a further preferred embodiment of the invention, the masking layer also has a transparent area and the opaque area preferably extends over less than 30%, particularly preferably over less than 20% and in particular over less than 10% of the total area of the composite pane. In this case, the masking layer is in the form of at least one thermoplastic composite film which has transparent areas in some areas and opaque areas in some areas. The proportion of the transparent areas is advantageously larger than the opaque areas if the laminated pane is to be used as a viewing pane, for example as a vehicle pane. 7

Alternatively, the thermoplastic intermediate layer can contain at least the masking layer and at least one transparent layer. The masking layer is also preferably completely opaque. The masking layer preferably extends over less than 30%, particularly preferably over less than 20% and in particular over less than 10% of the total area of the composite pane. The thermoplastic intermediate layer can also be formed by several masking layers and transparent layers. As a result, several composite films with different properties can be used in the production of the composite pane. In addition, it is technically easier to produce a completely colored composite film than a laminated pane that is only colored in certain areas. The masking layer and the transparent layer are designed as thermoplastic composite films. During production of the composite panes according to the invention, the thermoplastic composite films can overlap slightly due to the production process. Preferably, the transparent layer and the masking layer overlap 1 cm or less.

The masking layer and/or the transparent layer contain or consist of at least one thermoplastic, preferably polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) and/or polyurethane (PU) or copolymers or derivatives thereof, optionally in combination with polyethylene terephthalate (PET). However, the masking layer and/or the transparent layer can also be, for example, polypropylene (PP), polyacrylate, polyethylene (PE), polycarbonate (PC), polymethyl methacrylate, polyvinyl chloride, polyacetate resin, casting resin, acrylate, fluorinated ethylene propylene, polyvinyl fluoride and/or ethylene Tetrafluoroethylene, or a copolymer or mixture thereof.

The masking layer and/or the transparent layer are preferably in the form of at least one thermoplastic composite film and contain or consist of polyvinyl butyral (PVB), particularly preferably polyvinyl butyral (PVB) and additives known to those skilled in the art, such as plasticizers. The masking layer and/or the transparent layer preferably contain at least one plasticizer.

The masking layer and/or the transparent layer can be formed by a single composite film or by more than one composite film. The masking layer and / or the transparent layer can be formed by one or more stacked thermoplastic composite films, wherein the 8th

Thickness of the thermoplastic intermediate layer is preferably from 0.25 mm to 1 mm, typically 0.38 mm or 0.76 mm.

The masking layer and/or the transparent layer can also be a functional thermoplastic intermediate layer, in particular an intermediate layer with acoustically dampening properties, an intermediate layer reflecting infrared radiation, an intermediate layer absorbing infrared radiation and/or an intermediate layer absorbing UV (ultraviolet) radiation. For example, the transparent layer can also be a band filter film that blocks out narrow bands of visible light.

The masking layer has at least one opaque area or is completely opaque. The opaque area is preferably made opaque by a coloring or pigmentation, preferably black pigmentation. The coloring or pigmentation of the opaque area of the masking layer can be freely selected, but black is preferred.

In a further preferred embodiment of the laminated pane according to the invention, the masking layer is arranged at least adjacent to the lower edge of the laminated pane and preferably extends over at least 5% and particularly preferably over at least 10% of the total area of the laminated pane. In this example, the masking layer is preferably completely opaque. The masking layer is preferably located along the bottom edge and adjacent to the bottom edge. In the top view of the laminated pane, this results in a rectangular opaque stripe which is arranged along the lower edge. If the laminated pane is used, for example, as a windshield in a vehicle, this arrangement enables a projection arrangement with a high-contrast image in the area of the masking layer. Due to the arrangement of the masking layer along the lower edge, the see-through area of the laminated pane remains transparent.

In a particularly preferred embodiment of the invention, the opaque area of the masking layer is arranged in a peripheral frame-like manner in an edge area of the laminated pane and has a greater width in particular in a section that overlaps the reflection layer than in sections that differ from it. The masking layer can be completely opaque. In this case, the transparent layer is preferably arranged within the opaque frame formed by the masking layer. Alternatively, the area of the masking layer is within the opaque frame 9 preferably transparent. For the purposes of the present invention, “having a greater width” means that the opaque area in this section has a greater width perpendicular to the extension than in other sections. In this way, the opaque area can be suitably adapted to the dimensions of the reflection layer.

The reflection layer and the opaque area preferably each have a surface which is arranged congruently. Alternatively, the opaque area has a larger area than the reflective layer, and the reflective layer completely overlaps the opaque area. It is thus possible to obtain a full, high-contrast image when the light is reflected.

When describing, for example, that an element A completely overlaps with an element B, it is meant within the meaning of the invention that the orthonormal projection from element A to the surface plane of element B is completely inside element B.

In a further particular embodiment of the invention, the reflection layer extends over at least 50%, preferably at least 70%, particularly preferably at least 80%, over the total area of the laminated pane. In particular, the reflection layer is arranged congruently with the entire surface of the laminated pane. This has the advantage that a large area of the laminated pane is suitable for reflecting images. It is possible to provide several projection arrangements, each of which generates a reflected image in different areas of the laminated pane. If the laminated pane is used as a windshield, a head-up display area in the see-through area of the windshield could be used. At the same time, a high-contrast, reflected image can be generated in the overlapping area with the masking layer, which can also be visually perceived by the user.

The reflective layer is preferably partially translucent, which means in the context of the invention that it has an average transmission (according to ISO 9050:2003) in the visible spectral range of preferably at least 60%, more preferably at least 70% and in particular less than 85% and thereby View through the pane is not significantly restricted. The reflective layer preferably reflects at least 15%, particularly preferably at least 20%, very particularly preferably at least 30% of the light impinging on the reflective layer. The reflective layer preferably reflects 10 only p-polarized or s-polarized light. The reflection layer is intended to reflect a light of an image display device. The light reflected by the reflection layer is preferably visible light, i.e. light in a wavelength range from approx. 380 nm to 780 nm. The reflection layer preferably has a high and uniform degree of reflection (over different angles of incidence) compared to p-polarized and/or s-polarized radiation on, so that a high-intensity and color-neutral image display is guaranteed. The degree of reflection describes the proportion of the total radiation (light) that is reflected. It is given in % (relative to 100% incident radiation) or as a unitless number from 0 to 1 (normalized to the incident radiation). Plotted as a function of the wavelength, it forms the reflection spectrum. The information on the reflection of light relates to a reflection measurement with a light source A, which emits in the spectral range from 380 nm to 780 nm with a normalized radiation intensity of 100%. The portion of the radiation reflected by the reflection layer is measured, for example using a photo light spectrometer (for example from Perkin Elmer) and set in relation to the radiation intensity of the light source A.

The reflective layer can also be opaque. The reflective layer is preferably opaque if it is arranged congruently with the opaque area of the masking layer or if the reflective layer completely overlaps with the opaque area of the masking layer. The opaque reflection layer preferably reflects at least 60%, particularly preferably at least 70%, very particularly preferably at least 80% of the light impinging on the reflection layer.

The laminated pane according to the invention can additionally comprise a first masking strip, in particular made of a dark, preferably black, enamel. The first masking strip is in particular a peripheral, ie frame-like, masking print. The peripheral, first masking strip serves primarily as UV protection for the assembly adhesive of the laminated pane. The first masking strip can be designed to be opaque and to cover the entire surface. The first masking strip can also be semi-transparent, at least in sections, for example in the form of a dot grid, stripe grid or checkered grid. Alternatively, the first masking strip can also have a gradient, for example from an opaque covering to a semi-transparent covering. Suitable methods for producing a cover print and the different variants of cover prints are known to the person skilled in the art. 11

In addition to the first masking strip, further masking strips can be present, which, regardless of the design of the first masking strip, can be composed of the same materials and the same structure as the first masking strip.

In a particularly preferred embodiment of the invention, the first masking strip is applied in regions on the inside and/or the outside, preferably the inside, of the outer pane, with the heating element completely overlapping the first masking strip. In other words, the heating element is completely covered by the first masking strip when viewed through the laminated pane in the viewing direction from the outer pane to the inner pane. In addition, the opaque masking layer or the opaque area of the masking layer can overlap completely or in areas with the first masking stripe. Due to this arrangement, the heating element is not visible from an external environment, ie the environment facing the outer surface of the outer pane. This improves the aesthetic properties of the laminated pane.

The specification of the direction of polarization refers to the plane of incidence of the radiation on the laminated pane. P-polarized radiation is radiation whose electric field oscillates in the plane of incidence. S-polarized radiation is 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 laminated pane in the geometric center of the irradiated area.

In other words, the polarization, ie in particular the proportion of p- and s-polarized radiation, is determined at a point in the area irradiated by the image display device, preferably in the geometric center of the irradiated area. Since composite panes can be curved (for example when they are designed as windshields), which affects the plane of incidence of the image display device radiation, slightly different polarization components can occur in the other areas, which is unavoidable for physical reasons.

The reflection layer preferably comprises at least one metal selected from a group consisting of aluminum, tin, titanium, zirconium, hafnium, vanadium, niobium, tantalum, 12

Chromium, manganese, iron, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, or mixed alloys thereof. The reflective layer can also comprise silicon in combination with the metals mentioned above or independently thereof. Silicon can be very easily deposited as a coating on glass or foils using sputtering processes, which simplifies the production of the reflective layer.

In a particularly preferred embodiment of the invention, the reflection layer is a coating containing a thin layer stack, ie a layer sequence of thin individual layers. This thin layer stack contains one or more electrically conductive layers based on silver. The electrically conductive layer based on silver gives the reflective coating the basic reflective properties and also an IR-reflecting effect and electrical conductivity. The electrically conductive layer is based on silver. The conductive layer preferably contains at least 90% by weight silver, particularly preferably at least 99% by weight silver, very particularly preferably at least 99.9% by weight silver. The silver layer can have dopings, for example palladium, gold, copper or aluminum. Silver-based materials are particularly suitable for reflecting light, particularly preferably p-polarized light. The use of silver in reflective layers has proven to be particularly advantageous when reflecting light. The coating has a thickness of 5 μm to 50 μm and preferably 8 μm to 25 μm.

If something is designed “on the basis” of a material, then it mainly consists of this material, in particular essentially of this material in addition to any impurities or dopings.

The reflective layer can also be designed as a reflective coated or uncoated film that reflects light, preferably p-polarized light. The reflective layer can be a carrier film with a reflective coating or an uncoated reflective polymer film. The reflective coating preferably comprises at least one metal-based layer and/or a dielectric layer sequence with alternating refractive indices. The metal-based layer preferably contains or consists of silver and/or aluminum. The dielectric layers can, for example, be based on silicon nitride, zinc oxide, tin-zinc oxide, silicon-metal mixed nitrides such as silicon-zirconium nitride, zirconium oxide, niobium oxide, hafnium oxide, tantalum oxide, tungsten oxide or silicon carbide. The mentioned 13

Oxides and nitrides can be deposited stoichiometrically, under-stoichiometrically or over-stoichiometrically. They can have dopings, for example aluminum, zirconium, titanium or boron. The reflective uncoated polymer film preferably comprises or consists of dielectric polymer layers. The dielectric polymer layers preferably contain PET. If the reflective layer is in the form of a reflective film, it is preferably from 30 μm to 300 μm, particularly preferably from 50 μm to 200 μm and in particular from 100 μm to 150 μm thick.

If the reflective layer is designed as a coating, it is preferably applied to the inner pane by physical vapor deposition (PVD), particularly preferably by sputtering (“sputtering”) and very particularly preferably by cathode sputtering with magnetic field support (“magnetron sputtering”). In principle, however, the coating can also be applied, for example, by means of chemical vapor deposition (CVD), plasma-enhanced vapor deposition (PECVD), by vapor deposition or by atomic layer deposition (ALD). The coating is preferably applied to the panes before lamination.

In a particular embodiment of the invention, the reflective layer is arranged on the outside of the inner pane and, in addition, a further reflective layer is arranged on the inside of the inner pane. The reflection layer and the further reflection layer are arranged congruently in the viewing direction from the inner pane to the outer pane. Independently of the reflection layer, the further reflection layer can consist of the same materials and have the same structure as the reflection layer can. By coating the outside and the inside of the inner pane, the overall reflection of light impinging on the reflection layers can be improved.

If it is a coated, reflective film, the coating methods (vapor deposition or sputtering methods) CVD or PVD can also be used for production.

In a particularly preferred embodiment of the invention, the reflective layer is a reflective film that is metal-free and reflects visible light rays, preferably with p-polarization. The reflective layer is a film based synergistically 14 interacting prisms and reflective polarizers works. Such films for use with reflective layers are commercially available, for example from 3M Company.

In a further preferred embodiment of the invention, the reflection layer is a holographic optical element (HOE). The term HOE means elements based on the functional principle of holography. HOE change light in the beam path due to the information stored in the hologram, usually as a change in the refractive index. Their function is based on the superimposition of different plane or spherical light waves, whose interference pattern causes the desired optical effect. HOE are already being used in the transport sector, for example in head-up displays. The advantage of using an HOE compared to simply reflecting layers results from greater geometric design freedom with regard to the arrangement of the eye and projector positions and the respective angles of inclination, e.g. of projector and reflecting layer. Furthermore, with this variant, double images are particularly greatly reduced or even prevented. HOE are suitable for displaying real images or virtual images in different image widths. In addition, the geometric angle of the reflection can be adjusted with the HOE so that, for example, when used in a vehicle, the information transmitted to the driver can be displayed very well from the desired viewing angle.

In a preferred embodiment of the invention, the reflective layer is designed as a coated or uncoated reflective film, which is arranged between the opaque area of the masking layer and the transparent layer. The opaque area of the masking layer and the transparent layer overlap in areas where the reflection layer is arranged. The transparent layer and the opaque area are made thinner in the area of the overlap in order to prevent thickness differences in the laminated pane. The layer sequence is structured as follows in the area of the reflection layer:

- outer pane - opaque area of the masking layer - reflective layer - transparent layer - inner pane

In a further preferred embodiment, the laminated pane also comprises a first bus bar and a second bus bar, which can be connected to a 15

Voltage source are provided. The first and second busbars are connected to an edge region of the heating element in such a way that a current path through the heating element for a heating current is formed between the busbars. The first and the second bus bar are preferably applied to the outside of the inner pane or to the inside of the outer pane. The busbars are particularly preferably arranged in an edge area of the laminated pane. The heating element and the first and second busbars may be electrically connected to each other via wires. The wires preferably contain or consist of copper and/or tungsten.

The busbars can be covered by the opaque area of the masking layer, the first and/or the second masking strip towards the inner pane and/or towards the outer pane.

The first and the second bus bar can be formed as a printed and burned-in conductive structure. The printed busbars preferably contain at least one metal, a metal alloy, a metal compound and/or carbon, particularly preferably a noble metal and in particular silver. The printing paste preferably contains metallic particles, metal particles and/or carbon and, in particular, noble metal particles such as silver particles. The electrical conductivity is preferably achieved by the electrically conductive particles. The particles can be in an organic and/or inorganic matrix such as pastes or inks, preferably as a printing paste with glass frits. Such busbars are known per se to those skilled in the art.

The first and the second bus bar can be connected to a voltage source via connection lines. The connecting lines are preferably flat conductors (foil conductors, flat strip conductors) which are made from tinned copper, aluminum, silver, gold or alloys thereof.

The first and the second bus bar are preferably connected to a voltage source which provides an on-board voltage that is customary for motor vehicles, preferably from 12 V to 15 V and in particular about 14 V. Alternatively, the voltage source can also have higher voltages, preferably from 16 V to 450 V and in particular from 40 to 100 V. 16

The heating element can extend over the entire opaque area or can be arranged only in certain areas within the opaque area. Within the meaning of the invention, “within the opaque area” of the masking layer means that the heating element is completely surrounded by the opaque area of the masking layer, ie is in spatial contact with the opaque area of the masking layer from all spatial directions. The arrangement within the opaque area is preferably achieved in that the heating element is arranged and laminated between at least two thermoplastic composite films that are opaque at least in some areas. Alternatively, the heating element can be embedded in at least one partially opaque, thermoplastic composite film by pressure and heat, preferably during the lamination process to form the composite pane according to the invention. The heating element can extend beyond the opaque area over the entire surface of the laminated pane.

Within the scope of the present invention, composite foils can be individual foils or multilayer foils, which are used to connect adjacent foils, layers, panes or the like.

In a particularly preferred embodiment of the invention, the heating element is completely embedded within the opaque area of the masking layer. In addition, the heating element preferably extends over the entire surface of the opaque area. The heating element can thus be used to heat the entire opaque area and the adjacent areas.

In a preferred embodiment of the invention, the heating element is arranged in the area where the reflection layer overlaps with the opaque area. The heating element is therefore arranged behind the reflective layer in a view through the laminated pane (starting from the inner pane), so that the reflective layer completely covers the heating element. Alternatively, the reflective layer can also cover the heating element only in certain areas. This arrangement is particularly suitable for cases in which the reflection layer is arranged, for example, in the vicinity of the root of the pane, that is to say the lower edge of the laminated pane in the installed position. Since condensation tends to condense out on the inside of the inner pane, particularly in this area. 17

The heating element can be designed as an electrically conductive coating that is applied to a carrier film. The carrier film is preferably based on plastic, particularly preferably based on polyethylene terephthalate.

The electrically conductive coating typically contains one or more, for example two, three or four, electrically conductive functional layers. The functional layers preferably contain at least one metal, for example silver, gold, copper, nickel and/or chromium or a metal alloy. The functional layers particularly preferably contain at least 90% by weight of the metal, in particular at least 99.9% by weight of the metal. The functional layers can consist of the metal or the metal alloy. The functional layers particularly preferably contain silver or an alloy containing silver. Such functional layers have a particularly advantageous electrical conductivity combined with high transmission in the visible spectral range. The thickness of a functional layer is preferably from 5 nm to 50 nm, particularly preferably from 8 nm to 25 nm. In this range for the thickness of the functional layer, an advantageously high transmission in the visible spectral range and a particularly advantageous electrical conductivity are achieved.

At least one dielectric layer is preferably arranged in each case between two adjacent functional layers of the coating. A further dielectric layer is preferably arranged below the first and/or above the last functional layer. A dielectric layer contains at least a single layer of a dielectric material, for example containing a nitride such as silicon nitride or an oxide such as aluminum oxide. However, dielectric layers can also comprise a plurality of individual layers, for example individual layers of a dielectric material, smoothing layers, matching layers, blocking layers and/or antireflection layers. The thickness of a dielectric layer is, for example, from 10 nm to 200 nm.

This layer structure is generally obtained by a sequence of deposition processes which are carried out on the carrier film by a vacuum process such as magnetic field-assisted cathode sputtering.

Further suitable electrically conductive coatings preferably contain indium tin oxide (ITO), fluorine-doped tin oxide (SnC>2:F) or aluminum-doped zinc oxide (ZnO:Al). The functional layers preferably have a layer thickness of 8 nm to 25 nm, in particular 18 preferably from 13 nm to 19 nm. This is particularly advantageous with regard to transparency, color neutrality and surface resistance of the electrically conductive coating.

In an advantageous embodiment, the electrically conductive coating is a layer or a layer structure of several individual layers with a total thickness of less than or equal to 2 μm, particularly preferably less than or equal to 1 μm.

The total layer thickness of all electrically conductive layers is preferably from 40 nm to 80 nm, particularly preferably from 45 nm to 60 nm. In this range for the total thickness of all electrically conductive layers, the distances h between two busbars and an operating voltage are typical for vehicle windows, in particular windshields U in the range from 12 V to 15 V advantageously has a sufficiently high specific heating power P. In addition, the electrically conductive coating in this range has particularly good reflective properties for the infrared range for the total thickness of all electrically conductive layers. If the total layer thickness of all electrically conductive layers is too low, the surface resistance Ro _square is too high and the specific heating power P is too low, as well as reduced reflective properties for the infrared range.

In a very particularly preferred embodiment of the invention, the heating element is in the form of thin heating wires which are embedded at least in the opaque area of the masking layer. The advantage over the electrically conductive coating lies in the simple manufacture and arrangement of the heating wires, in contrast to the electrically conductive coating. For example, before the pane is joined to form the composite pane, the heating wires can be placed on a surface of a thermoplastic composite film which is intended to form the opaque area of the masking layer of the composite pane. During the manufacturing process of the laminated pane, the heating wires penetrate the masking layer as a result of pressure and increased temperature. Depending on the thickness of the heating wires used in each case, depressions in which the heating wires are arranged can be cut into the masking layer with the aid of methods known to those skilled in the art (“cutter”).

The heating wires can alternatively before connecting the outer pane and the inner pane in the thermoplastic intermediate layer, so the opaque area of the 19

Masking layer, are embedded, for example by pressing after heating the thermoplastic film. The heating wires can also be positioned between two thermoplastic films during the manufacturing process of the laminated pane. The heating wires preferably contain at least one metal, particularly preferably copper, tungsten, gold, silver, aluminum, nickel, manganese, chromium and/or iron, and mixtures and/or alloys thereof. The heating wires preferably have a thickness or a diameter of 10 μm to 300 μm, particularly preferably from 20 μm to 150 μm. This is particularly advantageous with regard to the electrical conductivity of the heating wires and the heat distribution in the laminated pane. The heating wires can be coated with an electrically insulating coating.

The heating wires are preferably arranged in a straight line within the opaque area of the masking layer. Alternatively, the heating wires can also be arranged in a partially or completely sinusoidal, zigzag, meandering or coil-like manner, preferably in a meandering manner. Combinations of these arrangements are also possible. This means that the heating wires can run sinusoidally, zigzag-shaped, meander-shaped or coil-shaped through the composite pane in a top view of the composite pane. This arrangement enables good heat distribution in the laminated pane. In addition, the desired heating power of the heating wires can be more precisely adjusted via the artificially lengthened distance between the bus bars.

In a particular embodiment of the invention, a high-index coating is applied to all or part of the inside of the inner pane. The high-index coating is preferably in direct spatial contact with the inside of the inner pane. The high-index coating is arranged at least in an area on the inside of the inner pane, which completely overlaps the reflection layer when viewed through the laminated pane. The reflection layer is therefore arranged spatially closer to the outside of the outer pane, but spatially further away from the inside of the inner pane than the high-index coating. This means that the light, preferably with a majority portion of p-polarized light, which is projected from the image display device onto the reflective layer, passes through the high-index coating before striking the reflective layer. 20

The high-index coating has a refractive index of at least 1.7, particularly preferably at least 1.9, very particularly preferably at least 2.0. The increase in the refractive index brings about a high refractive index effect. The high-refraction coating causes a weakening of the reflection of light and in particular p-polarized light on the interior-side surface of the inner pane, so that the desired reflection of the reflective coating appears with higher contrast.

According to a statement by the inventors, the effect is based on the increase in the refractive index of the interior-side surface as a result of the high-index coating. This increases the Brewster angle ot _Brewster at the interface, since this is known to be determined as a _Brewster = arctan ( ) where rii is the refractive index of air and PS is the refractive index of the material on which the radiation strikes. The high-index coating with the high refractive index leads to an increase in the effective refractive index of the glass surface and thus to a shift in the Brewster angle to larger values compared to an uncoated glass surface. As a result, with the usual geometric relationships of projection arrangements based on HUD technology, the difference between the angle of incidence and the Brewster angle is smaller, so that the reflection of the p-polarized light on the inside of the inner pane is suppressed and the ghost image generated as a result is weakened.

The high-index coating is preferably formed from a single layer and has no further layers below or above this layer. A single layer is sufficient to achieve a good effect and technically simpler than applying a stack of layers. In principle, however, the high-index coating can also comprise a number of individual layers, which can be desirable in individual cases in order to optimize certain parameters.

In the context of the present invention, refractive indices are preferably given in relation to a wavelength of 550 nm. Methods for determining refractive indices are known to those skilled in the art. The refractive indices specified within the scope of the invention can be determined, for example, by means of ellipsometry, with commercially available ellipsometers being able to be used (measuring device, for example, from Sentech). Unless otherwise stated, the specification of layer thicknesses or thicknesses relates to the geometric thickness of a layer. 21

Suitable materials for the high-index coating are silicon nitride (S13N4), a silicon-metal mixed nitride (e.g. silicon zirconium nitride (SiZrN), silicon-aluminum mixed nitride, silicon-hafnium mixed nitride or silicon-titanium mixed nitride), aluminum nitride, tin oxide, manganese oxide, tungsten oxide, niobium oxide, bismuth oxide, titanium oxide, tin-zinc composite oxide and zirconium oxide. In addition, transition metal oxides (such as scandium oxide, yttrium oxide, tantalum oxide) or lanthanide oxides (such as lanthanum oxide or cerium oxide) can also be used. The high-index coating preferably contains one or more of these materials or is based on them.

The high-index coating can be applied by a physical or chemical vapor deposition, ie a PVD or CVD coating (PVD: physical vapor deposition, CVD: chemical vapor deposition). Suitable materials on the basis of which the coating is preferably formed are in particular silicon nitride, a silicon-metal mixed nitride (for example silicon zirconium nitride, silicon-aluminum mixed nitride, silicon-hafnium mixed nitride or silicon-titanium mixed nitride), aluminum nitride, tin oxide, manganese oxide , tungsten oxide, niobium oxide, bismuth oxide, titanium oxide, zirconium oxide, zirconium nitride or tin-zinc mixed oxide. The high-index coating is preferably a coating applied by cathode sputtering (“sputtered”), in particular a coating applied by cathode sputtering with the assistance of a magnetic field (“magnetron-sputtered”).

Alternatively, the high refractive index coating is a sol-gel coating. In the sol-gel process, a sol containing the precursors of the coating is first prepared and matured. Ripening may involve hydrolysis of the precursors and/or a (partial) reaction between the precursors. The precursors are usually present in a solvent, preferably water, alcohol (especially ethanol) or a water-alcohol mixture. The sol preferably contains silicon oxide precursors in a solvent. The precursors are preferably silanes, in particular tetraethoxysilanes or methyltriethoxysilane (MTEOS). Alternatively, however, silicates can also be used as precursors, in particular sodium, lithium or potassium silicates, for example tetramethyl orthosilicate, tetraethyl orthosilicate (TEOS),

Tetraisopropyl orthosilicate, or organosilanes of the general form R2nSi(OR1)4-n. R1 is preferably an alkyl group, R2 is an alkyl, epoxy, acrylate, methacrylate, amine, phenyl or vinyl group, and n is an integer from 0 to 2. Silicon 22 halides or alkoxides are used. The silica precursors result in a sol-gel coating of silica. In order to increase the refractive index of the coating to the value, refractive index increasing additives are added to the sol, preferably titanium oxide and/or zirconium oxide, or their precursors. In the finished coating, the refractive index enhancing additives are present in a silicon oxide matrix. The molar ratio of silicon oxide to additives that increase the refractive index can be freely selected depending on the desired refractive index and is, for example, around 1:1.

If the reflective layer or the further reflective layer is arranged on the inside of the inner pane, the high-index coating can also be applied to the reflective layer or the further reflective layer. This arrangement is particularly useful if the reflection layer is arranged on the outside of the inner pane and the further reflection layer is arranged on the inside of the inner pane. The high-index coating improves the overall reflection of light that impinges on the reflective layer and the further reflective layer.

The outer pane and inner pane preferably contain or consist of glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass, alumino-silicate glass, or clear plastics, preferably rigid clear plastics, in particular polyethylene, polypropylene, polycarbonate, polymethyl methacrylate , polystyrene, polyamide, polyester, polyvinyl chloride and/or mixtures thereof.

The outer pane and inner pane can have other suitable coatings known per se, for example anti-reflective coatings,

Non-stick coatings, anti-scratch coatings, photocatalytic coatings or solar control coatings or low-e coatings.

The thickness of the individual panes (outer pane and inner pane) can vary widely and be adapted to the requirements of the individual case. Discs with standard thicknesses of 0.5 mm to 5 mm and preferably 1.0 mm to 2.5 mm are preferably used. The size of the discs can vary widely and depends on the use.

The composite pane can have any three-dimensional shape. Preferably, the outer pane and inner pane have no shadow zones, so that they, for example 23 can be coated by cathode sputtering. The outer pane and inner pane are preferably flat or slightly or strongly curved in one direction or in several spatial directions.

The invention extends further to a projection arrangement which comprises a composite pane according to the invention and an image display device assigned to the reflection layer. The image display device comprises an image display directed towards the reflective layer, the image of which can be reflected by the reflective layer and, after reflection, preferably leaves the composite pane according to the invention via the inside of the inner pane, with at least that region of the reflective layer being able to be irradiated by the image display device, which area overlaps with the opaque Area of the masking layer is. If a plurality of reflection layers are offset from one another in their extent, a corresponding number of image display devices can be provided.

The light emanating from the image display device is preferably visible light, i.e. light in a wavelength range of approximately 380 nm to 780 nm.

According to a preferred embodiment of the projection arrangement according to the invention, the image display, which can also be referred to as a display, as a liquid crystal (LCD) display, thin film transistor (TFT) display, light emitting diode (LED -) Display, Organic Light Emitting Diode (OLED) display, Electroluminescent (EL) display, microLED display, a display based on light field technology or the like, preferably as an LCD display. Due to the high reflection of p-polarized light, energy-intensive projectors, such as those usually used in head-up display applications, are not necessary. The display variants mentioned and other similarly energy-saving image display devices are sufficient. As a result, power consumption and heat radiation can be reduced.

In a preferred embodiment of the invention, the light of the image display device is at least 80% and preferably at least 90% p-polarized. Alternatively, the light from the image display device may be at least 80%, and preferably at least 90%, s-polarized. 24

The invention also extends to a method for producing a composite pane according to the invention. The procedure comprises the following steps in the order given:

(a) The outer pane, the thermoplastic intermediate layer, the heating element, the reflection layer and the inner pane are arranged to form a stack of layers.

The thermoplastic interlayer is placed between the outer pane and the inner pane and the heating element is placed within the opaque area of the masking layer.

The reflection layer is arranged spatially in front of the masking layer in the viewing direction from the inner pane to the outer pane and at least partially overlaps with the opaque area of the masking layer.

(b) The stack of layers is laminated to form a composite pane.

The layer stack is laminated under the action of heat, vacuum and/or pressure, the individual layers being connected (laminated) to one another by at least one thermoplastic intermediate layer. Methods known per se can be used to produce a laminated pane. For example, so-called autoclave processes can be carried out at an increased pressure of about 10 bar to 15 bar and temperatures of 130° C. to 145° C. for about 2 hours. Known vacuum bag or vacuum ring methods work, for example, at about 200 mbar and 130°C to 145°C. The outer pane, the inner pane and the thermoplastic intermediate layer can also be pressed in a calender between at least one pair of rollers to form a composite pane. Plants of this type are known for the production of laminated panes and normally have at least one heating tunnel in front of a pressing plant. The temperature during the pressing process is, for example, from 40°C to 150°C. Combinations of calender and autoclave processes have proven particularly useful in practice. Alternatively, vacuum laminators can be used. These consist of one or more chambers that can be heated and evacuated, in which the outer pane and the inner pane can be laminated within, for example, about 60 minutes at reduced pressures of 0.01 mbar to 800 mbar and temperatures of 80°C to 170°C.

Furthermore, the invention extends to the use of the composite pane according to the invention in means of locomotion for traffic on land, in the air or on water, especially in motor vehicles, the composite pane for example as 25

Windscreen, rear window, side windows and/or glass roof, can preferably be used as a windscreen. The use of the laminated pane as a vehicle windscreen is preferred. The laminated pane according to the invention can also be used as a functional and/or decorative individual piece and as a built-in part in furniture, appliances and buildings.

The invention extends further to the use of the projection arrangement according to the invention, which comprises a laminated pane according to the invention and an image display device assigned to the reflection layer. The image display device comprises an image display directed towards the reflective layer, the image of which is reflected by the reflective layer and then preferably leaves the laminated pane according to the invention via the inside of the inner pane, with at least that area of the reflective layer being irradiated by the image display device which overlaps with the opaque area of the masking layer is.

The various configurations of the invention can be implemented individually or in any combination. In particular, the features mentioned above and to be explained below can be used not only in the specified combinations, but also in other combinations or on their own, without departing from the scope of the present invention.

26

The invention is explained in more detail below using exemplary embodiments, reference being made to the attached figures. They show in a simplified representation that is not true to scale:

Figure 1 is a plan view of an embodiment of the invention

laminated pane,

FIG. 1a shows a cross-sectional view of a projection arrangement according to the invention with the composite pane from FIG.

FIG. 2 shows a further cross-sectional view of a projection arrangement according to the invention with a further embodiment of the laminated pane according to the invention and

FIG. 3-6 enlarged cross-sectional views of different configurations of the projection arrangement according to the invention.

FIG. 1 shows a top view of an embodiment of the laminated pane 1 according to the invention in a vehicle in a highly simplified, schematic representation. FIG. 1a shows a cross-sectional view of the exemplary embodiment from FIG. 1 in the projection arrangement 100. The cross-sectional view of FIG.

The laminated pane 1 comprises an outer pane 2 and an inner pane 3 with a thermoplastic intermediate layer 4 which is arranged between the outer pane and the inner pane 2 , 3 . The laminated pane 1 is installed in a vehicle and separates a vehicle interior 14 from an external environment 15 . For example, the laminated pane 1 is the windshield of a motor vehicle.

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. The thermoplastic intermediate layer 4 contains a masking layer 5 and a transparent layer 16. 27

The outside I of the outer pane 2 faces away from the thermoplastic intermediate layer 4 and is at the same time the outer surface of the laminated pane 1. The inside II of the outer pane 2 and the outside III of the inner pane 3 each face the intermediate layer 4. The inside IV of the inner pane 3 faces away from the thermoplastic intermediate layer 4 and is at the same time the inside of the composite pane 1. It goes without saying that the composite pane 1 can have any suitable geometric shape and/or curvature. As a composite pane 1, it typically has a convex curvature. The laminated pane 1 also has an upper edge located at the top in the installed position and a lower edge located at the bottom in the installed position, as well as a side edge located on the left and right.

In an edge region 13 of the laminated pane 1, a first masking strip 7 running around in the form of a frame is applied to the inside II of the outer pane 2. The first masking strip 7 is opaque and prevents the view of structures arranged on the inside of the composite pane 1, for example a bead of adhesive for gluing the composite pane 1 into a vehicle body. The first masking stripe 7 is preferably black. The first masking strip 7 consists of an electrically non-conductive material conventionally used for masking strips, for example a black-colored screen printing ink that is baked. The first masking stripe 7 is arranged such that the masking layer 5 completely overlaps the first masking stripe. This means that it covers the masking layer 5 and all other structures arranged behind it when looking through the laminated pane 1 starting from the outer environment 15 .

Furthermore, as shown in FIG. 1A, the laminated pane 1 has a second masking strip 8 in the edge region 13 on the inside IV of the inner pane 3 . The second masking strip 8 is designed in the form of a frame. Like the first masking strip 7, the second masking strip 8 consists of an electrically non-conductive material conventionally used for masking strips, for example a black-colored screen printing ink that is baked.

The transparent layer 16 consists of a thermoplastic composite film, preferably polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) and/or thermoplastic polyurethane (TPU). The transparent layer 16 extends from the upper edge area 13, 13'' (starting with the upper edge) over a flat area along the upper edge and the side edges 28 over the largest area (e.g. 85% of the area) of the inside II of the outer pane 2 and the outside III of the inner pane 3. The see-through area of the laminated pane 1 overlaps with the transparent layer 16. The transparent layer 16 borders on a lower area Masking layer 5. The masking layer 5 consists of an opaque thermoplastic composite film, preferably polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) and/or thermoplastic polyurethane (TPU). The masking layer 5 is colored black, for example. The masking layer 5 extends areally along the lower edge (in the edge region 13, 13') of the laminated pane 1 and along the side edges until it borders on the transparent layer 16. The transparent layer 16 and the masking layer 5 may overlap slightly (e.g. 5 mm) along the area where they are adjacent.

On the outside III of the inner pane 3, a reflection layer 11 is arranged in some areas, which is vapor-deposited by means of the PVD method. When looking through the laminated pane 1 from the external environment 15 , the reflection layer 11 is completely overlapped by the masking layer 5 . The reflective layer 11 is therefore not visible when viewed from the external environment 15 . In FIG. 1, the area in which the reflection layer 11 is arranged is indicated by dashed lines. The reflective layer 11 is arranged in such a way that it is not covered by the second masking strip 8 when looking through the laminated pane 1 from the vehicle interior 14 . In the example shown, the reflection layer 11 is arranged in strips along the lower edge in such a way that it completely covers the masking layer 5 but is not covered by the second masking strip 8 . The reflection layer 11 is, for example, a metal coating that contains at least one thin layer stack with at least one silver layer and one dielectric layer. Alternatively, the reflective layer 11 can also be designed as a reflective film and arranged on the outside III of the inner pane 3 . The reflective foil can contain a metal coating or consist of dielectric polymer layers in a layer sequence.

The laminated pane 1 also includes a heating element 6 which is arranged within the masking layer 5 . For example, the heating element 2 was arranged between the outer pane 2 and the masking layer 5 during the manufacturing process. The heating element 6 was surrounded by the masking layer 5 by pressure and heating during the lamination, so that the heating element 6 in the exemplary embodiment shown is closer to the inner surface II of the outer pane 2 than to the outer surface III of the 29

Inner pane 3 is arranged. The heating element 6 is in the form of, for example, heating wires. The heating wires are formed on the basis of copper, for example. The diameter of the heating wires 6 is about 100 μm, for example. The heating element 6 is arranged behind the reflective layer 11 when viewed through the laminated pane 1 starting from the vehicle interior 14 and is largely covered by this. The heating element 6 extends approximately orthogonally to the side edges and along the bottom edge. The heating element 6 is not visible from the outside environment 15 and the vehicle interior 14 since it is completely covered by the first masking strip 7 and by the masking layer 5 .

For electrical contact, the heating element 6 is materially and electrically connected to a first busbar in a left-hand edge area of the heating element and to a further, second busbar in a right-hand edge area of the heating element (not visible in FIG. 1 and FIG. 1a). The busbars contain silver particles, for example, and were applied using the screen printing process and then burned in. The length of the bus bars corresponds approximately to the extension of the heating element 6 along the side edges of the laminated pane 1. If an electrical voltage is applied to the bus bars, a uniform current flows through the heating element 6 between the bus bars. The busbars are connected to a voltage source by means of supply lines, which provides an on-board voltage that is customary for motor vehicles, preferably from 12 V to 15 V and, for example, about 14 V. Alternatively, the 14 V voltage source can also have higher voltages, for example from 35 V to 45 V and in particular 42 V. If a current flows through the heating element 6, the heating wires are heated as a result of their electrical resistance and Joule heat development. The area of the laminated pane 1 in which the heating element 6 is arranged can thus be freed from icing and condensation quickly and in an energy-efficient manner.

The projection arrangement 100 also has an image display device 10 arranged in the dashboard 9 as an image generator. The image display device 10 serves to generate light 12 (image information), which is directed onto the reflective layer 11 and is reflected by the reflective layer 11 as reflected light 12' into the vehicle interior 14, where it can be seen by an observer, e.g. driver. The reflective layer 11 is suitably designed to reflect the light 12 of the image display device 10, ie an image of the image display device 10. FIG. The light 12 of the image display device 10 is preferably incident at an angle of incidence of 50° to 80°, 30 in particular from 60° to 70° onto the composite pane 1, typically around 65°, as is usual with HUD projection arrangements. It would also be possible, for example, to arrange the image display device 10 in the A-pillar of a motor vehicle or on the roof (in each case on the vehicle interior side), if the reflection layer 11 is positioned in a suitable manner for this purpose. If a plurality of reflection layers 11 are provided, each reflection layer 11 can be assigned a separate image display device 10, ie a plurality of image display devices 10 can be arranged. The image display device 10 is, for example, a display such as an LCD display, OLED display, EL display, or pLED display. It would also be possible, for example, for the composite pane 1 to be a roof pane, side pane or rear pane.

The variant shown in FIG. 2 essentially corresponds to the variant from FIGS. 1 and 1a, so that only the differences are discussed here and otherwise reference is made to the description of FIGS. 1 and 1a.

In contrast to what is shown in FIGS. 1 and 1a, the reflection layer 11 in FIG. 2 extends over the entire surface over the entire outside III of the inner pane 3 and is applied to it. In contrast to what is shown here, however, it is also possible for the reflection layer 11 to be applied to the inside IV of the inner pane 3 . The reflection layer 11 is, for example, a metal coating that contains at least one thin layer stack with at least one silver layer and one dielectric layer. The reflection layer 11 is designed to be partially translucent, so that the reflection layer 11 reflects approximately 30% of the light 12 impinging on it and has approximately 70% transmission for the light 12 .

In this embodiment, the thermoplastic intermediate layer 4 consists solely of the masking layer 5, which, in contrast to FIGS 2 and the outside III of the inner pane 3 is arranged. The masking layer 5 has a transparent area 5″ and an opaque area 5′. Before lamination, it is a coherent composite film which is based, for example, on polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) and/or thermoplastic polyurethane ( TPU) is formed, but which is colored in a frame-shaped circumferential area 5' of the masking layer 5. The coloring is black, for example. The area 5'' 31 of the masking layer 5 within the section 5′ running around in the shape of a frame, on the other hand, is transparent and is therefore suitable for looking through. The thickness of the masking layer 5 is 0.76 mm, for example. When viewed through the laminated pane 1, the first masking strip 7 is applied congruently with the opaque region 5' of the masking layer 5 on the inner surface II of the inner pane.

The opaque area 5' of the masking layer 5 is widened in the lower (engine-side) section 13' of the edge area 13, i.e. the opaque area 5' has a greater width in the lower (engine-side) section 13' of the edge area 13 than in the upper (roof-side) section 13" of the edge area 13 (as well as in the lateral sections of the edge area 13, which cannot be seen in Figure 2) of the composite pane 1. "Width" is understood to mean the dimension of the opaque area 5' perpendicular to the lower edge of the inner and outer pane 2, 3 .

In this exemplary embodiment, the heating element 6 could also be arranged in the upper roof-side section 13' within the opaque region 5' of the masking layer 5. In addition, in order to achieve a circumferential heating effect, the heating element 6 could also be arranged in the extension direction from the upper edge to the lower edge along and in the side edge region.

Furthermore, several image display devices 10 could be provided, which, for example, irradiate the lower (engine-side) section 13' and the upper (roof-side) section 13" of the edge region 13 with visible light 12. For example, the image display devices 10 could be arranged such that a (partly ) circulating, high-contrast image is generated.

Due to the fact that the reflection layer 11 extends over the entire outside III of the inner pane 3, all areas of the laminated pane 1 can be used to reflect an image. It is possible to use further image display devices which, for example, irradiate areas of the reflection layer 11 that do not overlap with the opaque area 5 ′ of the masking layer 5 , ie are located in the see-through area of the laminated pane 1 , for example. This allows the function of a head-up display to be used. 32

Reference is now made to Figures 3 to 6, wherein enlarged cross-sectional views of various configurations of the composite pane 1 are shown. The cross-sectional views of FIGS. 3 to 6 correspond to the section line A-A' in the lower section 13' of the edge region 13 of the laminated pane 1, as indicated in FIG. 1a.

FIG. 3 shows an enlarged cross-sectional view in the edge region 13' of FIG. 1a. In the variant of the laminated pane 1 shown in FIG. 3, the completely opaque masking layer 5 is arranged between the outer pane 2 and the inner pane 3 . In the example shown, the masking layer 5 is in direct physical contact with the reflection layer 11 and the first masking strip 7 . The reflection layer 11 is arranged on the outside III of the inner pane 3 . The light 12 from the image display device 10 is reflected by the reflection layer 11 into the vehicle interior 14 as reflected light 12'. The light 12, 12' can have s- and/or p-polarization. Due to the angle of incidence of the light 12 on the laminated pane 1 close to Brewster's angle, the p-polarized component of the light 12 is hardly prevented from transmitting through the inner pane 3 . This variant has the advantage that a relatively large proportion of the incident, p-polarized light 12 is reflected and then largely unhindered by the Inner pane 3 is transmitted into the vehicle interior 14 . The image is also easily recognizable against the background of the opaque masking layer 5 with high contrast. The heating element 5 is not visually perceptible from the external environment 15 through the first masking strip 7 . Due to the opaque masking layer 5, the heating element is also not visually perceptible from the vehicle interior 14 out.

The heating wires of the heating element 6 are arranged within the opaque masking layer 5 with their extension direction orthogonal to the cross-sectional plane. The individual heating wires are arranged at a distance of, for example, about 1 mm from one another from the lower to the upper section of the enlarged cross section.

The variants shown in FIGS. 4 to 6 essentially correspond to the variant from FIGS. 1, 1a and FIG. 3, so that only the differences are discussed here and otherwise reference is made to the description of FIGS. 33

In contrast to what is shown in FIG. 3, in FIG. 4 the reflection layer 11 is not applied to the outside III of the inner pane 3 but to the inside IV of the inner pane 3 . This variant has the advantage that the incident light 12 is not prevented from being transmitted through the inner pane 3 . In addition, it is also preferred for light 12 with a high s-polarized component, since there are fewer double images as a result of the reflection on the inner pane 3 .

The variant of the composite pane 1 shown in FIG. 5 differs from the variant of FIG. 3 only in that a high-index coating 17 is arranged on the inside IV of the inner pane 3 . The high-index coating 17 is applied, for example, using the sol-gel process and consists of a titanium oxide coating. Due to the higher refractive index (e.g. 1.7) of the high-index coating 17 compared to the inner pane 3, the Brewster angle (for soda-lime glass) which is normally around 56.5° can be changed, which simplifies the application and the Effect of disturbing double images reduced by the reflection on the inside IV of the inner pane 3.

The variant of the laminated pane 1 shown in Figure 6 differs from the variant of Figure 3 in that a further reflection layer 11" is arranged on the inside IV of the inner pane 3 in addition to the first reflection layer 1T on the outside III of the inner pane 3 the high-index coating 17 is applied to the further reflection layer 11". This arrangement offers great advantages when the reflection layers 11', 11" each individually reflect smaller portions (<10%) of the incident light 12. The arrangement on both the outside III and the inside IV of the inner pane 3 improves the overall reflection of the incident light 12. The high-refraction coating 17 also helps to avoid disruptive double images due to the reflection on the inside IV of the inner pane 3

In all of the exemplary embodiments, the reflection layer 11 is arranged on the vehicle interior side of the masking layer 5, i.e. the reflection layer 11 is located in front of the masking layer 5 when looking at the inside of the laminated pane 1.

It follows from the above statements that the invention provides an improved composite pane for a projection arrangement which enables a good image display with high contrast. Unwanted secondary images can be avoided. Because of 34

Using the heating element together with the composite pane can significantly reduce the space in the dashboard area when installed in a vehicle, which can open up opportunities for a slimmer design in the vehicle interior. By means of the image display via the reflection layer in front of the masking layer, the display with speedometer, engine speed indicator, warning indicator and fuel gauge, which is usually attached to the dashboard, can be replaced. The heating of the laminated pane by the heating element replaces supply lines, which usually direct air heated by engine heat to the windshield. Furthermore, there are additional geometric degrees of freedom in the design of the vehicle interior if the air outlet nozzles, which are usually attached in a specific geometric relationship to the glazing, are omitted. The laminated pane according to the invention can be produced simply and inexpensively using known production processes.

35

Reference List

1 composite pane

2 outer pane

3 inner pane

4 thermoplastic interlayer

5 masking layer 5' opaque area

5" transparent area

6 heating element

7 first masking strip

8 second masking strips

9 dashboard

10 Image display device 11 Reflective layer

12, 12' light

13, 13', 13" edge area

14 vehicle interior

15 external environment

16 transparent layer 17 high-index coating 100 projection arrangement

I Outside of the outer pane 2

II Inside of the outer pane 2

III Outside of inner pane 3

IV Inside of the inner pane 3

A-A' cutting line

Claims

36

Laminated pane (1), in particular for a projection arrangement (100), at least comprising: 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), wherein the outer pane (2) and the inner pane (3) each have an outside (I, III) and an inside (II, IV) and the inside (II) of the outer pane (2) and the outside (III) of the inner pane (3) facing each other and the thermoplastic intermediate layer (4) contains or consists of at least one masking layer (5) and the masking layer (5) is opaque at least in one area (5'), a heating element (6) which is located within the opaque area ( 5') of the masking layer (5), and a reflection layer (11) which is suitable for reflecting visible light (12), the reflection layer (11) in the viewing direction from the inner pane (3) to the outer pane (2) spatial I is arranged in front of the masking layer (5) and at least partially overlaps with the opaque area (5') of the masking layer (5). Laminated pane (1) according to Claim 1, in which the masking layer (5) also has a transparent region (5") and the opaque region (5') is preferably less than 30%, more preferably less than 20% and in particular less than 10% of the total area of the composite pane (1).Composite pane (1) according to claim 1, wherein the thermoplastic intermediate layer (4) contains the masking layer (5) and a transparent layer (16) and the masking layer (5) is completely opaque, the masking layer preferably extends over less than 30%, particularly preferably over less than 20% and in particular over less than 10% of the total area of the composite pane (1). 37 Composite pane (1) according to one of claims 1 to 3, wherein the masking layer (5) is arranged at least adjacent to a lower edge of the composite pane (1) and preferably over at least 5% and particularly preferably over at least 10% of the total area of the composite pane ( 1) extends. Laminated pane (1) according to one of claims 1 to 4, wherein the opaque region (5') of the masking layer (5) is arranged in a peripheral frame-like manner in an edge region of the laminated pane (1) and in particular in a section (12') which overlaps to the reflection layer (11), has a greater width than in sections (12") different therefrom. Laminated pane (1) according to one of claims 1 to 5, wherein the reflection layer (11) and the opaque region (5') each have a surface which are arranged congruently, or the opaque area (5') has a larger area than the reflection layer (11) and the reflection layer (11) completely overlaps with the opaque area (5') Laminated pane (1) according to one of the claims 1 to 6, which also includes a first masking strip (7) which is applied in some areas to the inside (II) of the outer pane (2), and wherein at least the heating element (6) is completely covered with the first masking strip fen (7) overlapped. Laminated pane (1) according to one of claims 1 to 7, wherein the reflection layer (11) has an average transmission in the visible spectral range of preferably at least 60%, particularly preferably at least 70% and in particular less than 85% and / or the reflection layer (11) preferably at least 15%, particularly preferably at least 20%, very particularly preferably at least 30% of the light (12) incident on the reflective layer (11) is reflected. Laminated pane (1) according to one of Claims 1 to 8, which also comprises a first bus bar and a second bus bar which are intended for connection to a voltage source, 38, the first and second busbars being connected to an edge region of the heating element (6) in such a way that a current path through the heating element (6) for a heating current is formed between the busbars.

10. Laminated pane (1) according to one of claims 1 to 9, wherein the heating element (6) is completely embedded in the opaque region (5') of the masking layer (5).

11. Laminated pane (1) according to one of claims 1 to 10, wherein the heating element (6) is in the form of heating wires which preferably have a diameter of 10 μm to 300 μm and particularly preferably 20 μm to 150 μm.

12. Laminated pane (1) according to claim 11, wherein the heating wires contain or consist of a metal, preferably contain or consist of copper and/or tungsten.

13. Laminated pane (1) according to one of claims 1 to 12, wherein a high-index coating (17) with a refractive index of at least 1.7 is arranged at least in a region of the inside (IV) of the inner pane (3) which overlaps with of the reflection layer (11), and wherein the high-index coating (17) is always spatially arranged in front of the reflection layer (11) when looking at the inside (IV) of the inner pane (3).

14. Projection arrangement (100), comprising: a composite pane (1) according to any one of claims 1 to 13, an image display device (10) assigned to the reflection layer (11) and having an image display directed onto the reflection layer (11), the image of which is projected from the reflection layer ( 11) is reflective, at least that region of the reflective layer (11) being able to be irradiated by the image display device (10) which is in overlap with the opaque region (5') of the masking layer (5).

15. A method for producing a composite pane (1) according to any one of claims 1 to 13, wherein: 39

(a) the outer pane (2), the thermoplastic intermediate layer (4), the heating element (6), the reflection layer (11) and the inner pane (3) are arranged to form a stack of layers, with the thermoplastic intermediate layer (4) between the outer pane ( 2) and the inner pane (3) is arranged and the heating element (6) within the opaque

area (5') of the masking layer (5), and wherein the reflection layer (11) is arranged spatially in front of the masking layer (5) in the viewing direction from the inner pane (3) to the outer pane (2) and at least partially with the opaque area (5') of the masking layer (5), (b) the layer stack obtained is laminated to form a composite pane (1). Use of the laminated pane (1) according to one of Claims 1 to 13 in vehicles for traffic on land, in the air or on water, in particular as a vehicle windscreen.