EP4449190A1

EP4449190A1 - Composite pane for a projection assembly

Info

Publication number: EP4449190A1
Application number: EP22823542.0A
Authority: EP
Inventors: Julian GREVERATH; Jan Hagen; Andreas GOMER; Valentin SCHULZ
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: 2021-12-15
Filing date: 2022-12-01
Publication date: 2024-10-23
Also published as: WO2023110428A1; CN116615687A

Abstract

The invention relates to a composite pane (100) at least comprising an outer pane (1), a masking layer (2), a first thermoplastic intermediate layer (3), an optical multi-layer film (4) having a section (A) formed as a concave mirror, a second thermoplastic intermediate layer (5) and an inner pane (6), wherein the optical multi-layer film (4) is arranged between the outer pane (1) and the inner pane (6), the first thermoplastic intermediate layer (3) is arranged between the outer pane (1) and the optical multi-layer film (4), the second thermoplastic intermediate layer (5) is arranged between the optical multi-layer film (4) and the inner pane (2), the masking layer (2) is arranged in a region of the composite pane (100) between the outer pane (1) and the optical multi-layer film (4), and wherein at least the section (A) of the optical multi-layer film (4) designed as a concave mirror is arranged in a region of the composite pane (100) that lies entirely in the region in which the masking layer (2) is arranged with a perpendicular view through the composite pane (100).

Description

SAINT-GOBAIN GLASS FRANCE 2021332-WO-PCT

COMPOSITE PANEL FOR A PROJECTION ARRANGEMENT

The invention relates to a composite pane for a projection arrangement, a method for its production and its use, and a projection arrangement.

Modern automobiles are increasingly being equipped with so-called head-up displays (HUDs), as are known, for example, from DE 10 2009 020824 A1. Images are projected onto the windshield with a projector, typically in the area of the dashboard, where they are reflected and perceived by the driver as a virtual image (from his perspective) behind the windshield. In this way, important information can be projected into the driver's field of vision, for example the current driving speed, navigation or warning information, which the driver can perceive without having to take his eyes off the road. Head-up displays can thus make a significant contribution to increasing road safety.

US 2019/0299752 A1 discloses a composite pane for a head-up display and EP 0 844 507 A1 discloses a head-up display system.

However, head-up displays often have the problem that the area of the windshield intended for reflecting the light projected by the projector must have a high level of transparency, generally at least 70%. The reflected light of the projector is therefore superimposed by light from the external environment, which, depending on the lighting conditions, can lead to a reduction in contrast in the virtual image and thus to poorer visual perceptibility for the driver. Sufficient visual perceptibility of information that is particularly relevant to safety, such as lane assistance, speedometer or engine speed, should be guaranteed in all weather and light conditions. It would be desirable to have a projection arrangement based on head-up display technology in which no unwanted secondary images occur and whose arrangement can be implemented relatively easily with good visibility and sufficient brightness and contrast of the displayed image information. In order to achieve this, it is necessary to increase the contrast in the reflective area of the windshield. The increase in contrast can be achieved, for example, in that the background of the reflection area is largely or completely opaque. In addition, head-up displays often have the problem that the position of the imaging unit is dictated by the geometry and the angle of inclination of the laminated pane. In order to enlarge the virtual image, the distance between the imaging unit and the windshield can be changed or the size of the imaging unit can be increased.

WO 2020/136646 A1 discloses a multilayer thin optical combiner configured to augment a real world view with virtual images and applied to the surface of a large transparent window.

US 5 598 175 A discloses a display device in a vehicle, which has a display device for displaying vehicle information, a hologram plate with a reflection function, mounted in the lower area of a windshield, the hologram plate redirecting display light from the display device to the driver of the vehicle, and having a dark part , which is attached to the back of the hologram plate, shielding it from external light penetrating into it.

The object of the present invention is to provide an improved composite pane for a projection arrangement.

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.

The invention relates to a laminated pane at least comprising an outer pane, a masking layer, a first thermoplastic intermediate layer, an optical multilayer film, a second thermoplastic intermediate layer and an inner pane.

The laminated pane is intended to separate the interior from the outside environment in a window opening of a vehicle. In the context of the invention, the inner pane refers to the pane of the laminated pane facing the vehicle interior. The outer pane refers to the pane facing the outside environment. The laminated pane has an upper edge and a lower edge, as well as two side edges running in between. The top edge designates that edge which is intended to point upwards in the installation position. The lower edge designates that edge which is intended to point downwards in the installation position. In the case of a windshield, the top edge is often referred to as the roof edge and the bottom edge as the engine edge.

The outer pane and the inner pane each have an outside and an inside surface and a circumferential side edge running in between. Within the meaning of the invention, the outside surface designates that main surface which is intended to face the external environment in the installed position. Within the meaning of the invention, the interior-side surface designates that main surface which is intended to face the interior in the installed position. The interior surface of the outer pane and the outside surface of the inner pane face each other and are connected to each other by the first thermoplastic intermediate layer and the second thermoplastic intermediate layer.

The outside surface of the outer pane is referred to as side I. The surface of the outer pane on the interior side is referred to as side II. The outside surface of the inner pane is referred to as Side III. The interior side surface of the inner pane is referred to as side IV.

According to the invention, the optical multilayer film has a section designed as a concave mirror and is arranged between the outer pane and the inner pane.

The concave mirror is preferably a strip-like, in particular cylindrical, concave mirror over essentially the entire width of the laminated pane with an axis of rotation in the y-direction according to the vehicle coordinate system. Accordingly, the projected image is enlarged only in the vertical direction by means of the concave mirror.

The first thermoplastic interlayer is positioned between the outer pane and the multilayer optical film, and the second thermoplastic interlayer is positioned between the multilayer optical film and the inner pane. It goes without saying that the first thermoplastic intermediate layer and the second thermoplastic intermediate layer are each arranged over their entire surface between the outer pane and the inner pane. Both the first thermoplastic intermediate layer and the second thermoplastic intermediate layer thus extend over the entire laminated pane.

The masking layer is arranged between the outer pane and the optical multilayer film in a region of the laminated pane.

According to the invention, at least the section of the optical multilayer film designed as a concave mirror is arranged in a region of the laminated pane which, when viewed perpendicularly through the laminated pane, lies entirely in the region in which the masking layer is arranged. Thus, when looking through the laminated pane from the inside, the masking layer is arranged at least behind the section of the optical multilayer film designed as a concave mirror.

The expression "located in the area in which the masking layer is arranged" means that the section of the optical multilayer film designed as a concave mirror is arranged in a vertical view through the laminated pane or in orthogonal projection through the pane in overlap with the masking layer. The section of the optical multilayer film designed as a concave mirror has no section that does not overlap the masking layer, i.e. the concave mirror is only formed where it is located in front of the masking layer when looking at the inside of the laminated pane.

In a preferred embodiment, the multilayer optical film is arranged over the entire surface between the first thermoplastic intermediate layer and the second thermoplastic intermediate layer. The multilayer optical film thus extends over the entire surface of the laminated pane. Consequently, in this embodiment, the optical multilayer film is also arranged over the entire surface between the outer pane and the inner pane. As described above, a section of the multilayer optical film is designed as a concave mirror.

In an alternative preferred embodiment, the optical multi-layer film is only arranged in a region of the laminated pane which, when viewed perpendicularly through the laminated pane, lies entirely in the region in which the masking layer is arranged is. In this embodiment, the optical multilayer film thus only extends over a partial area of the laminated pane. As described above, a section of the multilayer optical film is designed as a concave mirror. In this embodiment, the laminated pane additionally has a third thermoplastic intermediate layer which surrounds the optical multilayer film like a frame, ie the third thermoplastic intermediate layer has a recess in which the optical multilayer film is accommodated.

In this embodiment, the outer dimensions of the gap in the third thermoplastic intermediate layer essentially correspond to the outer dimensions of the multilayer optical film, i.e. the gap and the multilayer optical film have essentially the same geometry.

Substantially the same outer dimensions means that the outer dimensions deviate from one another by a maximum of 1 mm, preferably by a maximum of 50 μm (micrometers).

The third intermediate thermoplastic layer has a thickness substantially the same as the thickness of the multilayer optical film, i.e., the multilayer optical film and the third intermediate thermoplastic layer have essentially the same thickness.

Substantially the same thickness means that the thickness differs by a maximum of 50 μm.

The multilayer optical film preferably comprises at least a first film having an outside surface and an inside surface and a second film having an outside surface and an inside surface, the inside surface of the first film and the outside surface of the second film facing each other. At least in the section of the optical multilayer film designed as a concave mirror, a reflection layer for reflecting light is arranged between the first film and the second film. The reflection layer is preferably only arranged in that section of the optical multilayer film which is designed as a concave mirror. An adhesive layer, for example made of a thermoplastic film or an optically clear adhesive, can optionally be arranged between the first film and the second film. The reflective layer can be formed, for example, as a reflective coating on the interior-side surface of the first film or as a reflective coating on the outside surface of the second film or as a reflective film.

In a preferred embodiment, the multilayer optical film comprises a first film having an outside surface and an inside surface and a second film having an outside surface and an inside surface, wherein the inside surface of the first sheet and the outside surface of the second sheet face each other. In the section of the optical multilayer film designed as a concave mirror, the first film has an essentially plano-concave cross section and the second film has an essentially plano-convex cross section. In addition, a reflective layer for reflecting light is arranged at least in the section of the optical multilayer film designed as a concave mirror between the first film and the second film. An adhesive layer, for example made of a thermoplastic film or an optically clear adhesive, can optionally be arranged between the first film and the second film.

In this embodiment, the reflective layer can be formed, for example, as a reflective coating on the interior-side surface of the first film or as a reflective coating on the outside surface of the second film or as a reflective film.

In a further preferred embodiment, the optical multilayer film comprises a plurality of films, with a reflection layer for reflecting light being arranged in sections between two adjacent films in the section designed as a concave mirror and the reflection layers arranged in sections together defining the concave mirror. The optical multilayer film thus has a structure comparable to a Fresnel lens in the section designed as a concave mirror. Optionally, an adhesive layer, for example made of a thermoplastic film or an optically clear adhesive, can be arranged between each two adjacent films.

In this embodiment, the reflective layer can be formed, for example, as a reflective coating. As described above, the reflection layer is a reflection layer for reflecting light. The reflection layer is preferably opaque or 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 most 80%, particularly preferably at most 50% and in particular less than 10%. The reflective layer preferably reflects at least 10%, particularly preferably at least 50%, very particularly preferably at least 80% and in particular at least 90% of the light impinging on the reflective layer. The reflection layer preferably reflects p-polarized and s-polarized light in equal proportions, but it can also reflect p-polarized light and s-polarized light to different degrees.

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 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 imaging unit, preferably in the geometric center of the irradiated area. Since compound panes can be curved (e.g. if they are designed as windscreens), which affects the plane of incidence of the radiation, slightly deviating polarization components can occur in the other areas, which is unavoidable for physical reasons.

In a preferred embodiment of the invention, the reflection layer is a metallic layer, ie a layer that contains or consists of metal. In this embodiment of the laminated pane according to the invention, the reflective layer preferably contains at least one metal selected from a group consisting of aluminum, magnesium, tin, indium, titanium, tantalum, niobium, nickel, copper, chromium, cobalt, iron, manganese, zirconium, cerium, scandium yttrium, silver, gold, platinum and palladium, ruthenium or mixtures thereof. Aluminum, titanium, and/or nickel are preferred because they can exhibit high reflectance for p-polarized or s-polarized light. In particular, aluminum is preferred.

The reflection layer preferably has a thickness of 10 nm (nanometers) to 100 μm (micrometers), particularly preferably from 50 nm to 50 μm, in particular from 100 nm to 5 μm.

In a particular 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 nickel, titanium and/or aluminum. The electrically conductive layer based on nickel, titanium and/or aluminum gives the reflective layer basic reflective properties and also an IR-reflecting effect and electrical conductivity. The electrically conductive layer is based on nickel, titanium and/or aluminum. The conductive layer preferably contains at least 90% by weight nickel, titanium and/or aluminum, particularly preferably at least 99% by weight aluminum, very particularly preferably at least 99.9% by weight nickel, titanium and/or aluminum. The layer based on aluminum, nickel and/or titanium can have dopings, for example palladium, gold, copper or silver. Materials based on aluminum, nickel and/or titanium are particularly suitable for reflecting light, particularly preferably p-polarized light. The use of nickel, titanium and/or aluminum in metallic coatings has proven particularly advantageous for the reflection of light. Aluminum, nickel and/or titanium are significantly cheaper than many other metals such as gold or silver. The individual layers of the thin-layer stack preferably have a thickness of 10 nm to 1 μm. The thin layer stack preferably has 2 to 20 individual layers and in particular 5 to 10 individual layers. As described above, in embodiments the reflective layer can be embodied as a reflective film, in particular as a polyethylene terephthalate (PET)-based film that is coated with a copolymer layer stack based on PET and/or polyethylene naphthalate (PEN). The coating is preferably applied to the interior-side surface, ie the surface that faces the vehicle interior. Suitable reflective films are described in US Pat. No. 5,882,774 A, for example.

As described above, in the laminated pane according to the invention, a masking layer is arranged in one area of the laminated pane. The masking layer is preferably arranged in an edge region of the composite pane, which typically borders on the edge of the pane. The great advantage of this arrangement arises when the composite pane is used as a windshield in a vehicle, since the masking layer is located in an edge area outside the driver's main viewing area.

The masking layer is preferably arranged at least 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.

In a particularly preferred embodiment of the laminated pane according to the invention, the masking layer is designed to run around the circumference in the shape of a frame. In a section in which the area of the optical multilayer film designed as a concave mirror is arranged overlapping the masking layer, the frame-shaped masking layer is preferably widened, i.e. has a greater width (dimension perpendicular to the extension) than in other sections. In this way, the masking layer can be suitably adapted to the dimensions of the region of the optical multilayer film designed as a concave mirror.

When the laminated pane is installed in a vehicle, the region of the optical multilayer film designed as a concave mirror is at a smaller distance from the vehicle interior than the masking layer.

Due to the fact that the area of the optical multilayer film designed as a concave mirror is arranged in an area of the laminated pane which, when viewed perpendicularly through the laminated pane lies completely in the area in which the masking layer is arranged, the reflection layer arranged in this area is also arranged in an area which, in a vertical view through the laminated pane, lies completely in the area in which the masking layer is arranged. Thus, the reflection layer arranged in the area designed as a concave mirror is arranged to overlap the masking layer in a vertical view through the composite pane or in an orthogonal projection through the composite pane. The reflective layer preferably has no section that does not overlap the masking layer, ie the reflective layer is preferably only formed where it is located in front of the masking layer as viewed on the inside of the laminated pane.

The area of the optical multilayer film designed as a concave mirror preferably has essentially the shape of a rectangle, which extends in an area close to the lower edge between the two side edges of the laminated pane. Particularly preferably, the side edges of the optical multilayer film do not reach the side edges of the laminated pane, but are spaced from them, for example, by 2 cm to 5 cm.

The masking layer within the meaning of the invention is a layer that prevents the view through the laminated pane. In this case, a transmission of at most 5%, preferably at most 2%, particularly preferably at most 1%, in particular at most 0.1%, of the light of the visible spectrum takes place through the masking layer. The masking layer is therefore an opaque masking layer, preferably a black masking layer.

The masking layer is preferably a coating of one or more layers. Alternatively, the masking layer can also be an opaque film or a colored area of the thermoplastic intermediate layer. According to a preferred embodiment of the laminated pane, the masking layer consists of a single layer. This has the advantage of particularly simple and cost-effective production of the laminated pane, since only a single layer has to be formed for the masking layer.

The masking layer is, in particular, an opaque cover print made from a dark, preferably black, enamel. In a preferred embodiment, the masking layer is designed as an opaque covering print arranged on the interior-side surface of the outer pane, in particular made of a dark, preferably black, enamel.

In an alternative preferred embodiment, the masking layer is designed as an opaque cover print arranged between the first thermoplastic intermediate layer and the optical multilayer film, in particular made of a dark, preferably black, enamel, or as an opaque film arranged between the first thermoplastic intermediate layer and the optical multilayer film.

In an alternative preferred embodiment, the masking layer is formed as an opaque colored area of the first thermoplastic intermediate layer.

In one embodiment, the first thermoplastic intermediate layer is formed in one piece and is colored opaque in one area.

A masking layer formed as an opaque colored area of the first thermoplastic intermediate layer can also be realized by using a first thermoplastic intermediate layer composed of an opaque thermoplastic film and a transparent thermoplastic film. The opaque thermoplastic film and the transparent thermoplastic film are preferably offset from one another, so that both films do not overlap when viewed through the laminated pane. The transparent thermoplastic film and the opaque thermoplastic film consist of the same plastic or preferably contain the same plastic. The materials on the basis of which the opaque thermoplastic film and the transparent thermoplastic film can be formed are those which are also described for the first thermoplastic intermediate layer. The opaque thermoplastic film is preferably a colored film, which may be of various colors, particularly black.

The masking layer can also be in the form of an opaque film arranged between the outer pane and the first thermoplastic intermediate layer. In a preferred embodiment of the laminated pane according to the invention, a high-index coating with a refractive index of at least 1.7 is arranged on the interior-side surface of the inner pane.

The high-index coating causes an increase in the refractive index of the surface of the inner pane on the interior side. This increases the Brewster angle «Brewster at the interface, since this is known to be determined as a _Brewster = arctan(- ) where ni ni is the refractive index of air and n ₂ 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. With the usual geometric relationships of HUD projection systems in vehicles, the difference between the angle of incidence and the Brewster angle is thereby reduced, so that the reflection of p-polarized radiation on the surface on the interior side is suppressed and a ghost image generated thereby is weakened.

In the context of the present invention, refractive indices are generally 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. Unless otherwise stated, the specification of layer thicknesses or thicknesses relates to the geometric thickness of a layer.

Suitable materials for the high-index coating are silicon nitride (SisN^, 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 mixed 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 be used. The high-index coating preferably contains one or more of these materials or is formed on their basis.

Suitable high-index coatings are disclosed, for example, in WO 2021/209201 A1. In one embodiment of the composite pane according to the invention, the main axis of the concave mirror is inclined relative to the perpendicular of the composite pane, so that the main plane of the concave mirror does not run parallel to the main plane of the composite pane.

The laminated pane according to the invention can optionally additionally have an opaque cover print arranged on the interior-side surface of the inner pane, in particular a frame-shaped cover print in a peripheral edge region. Such a masking print on the interior-side surface of the inner pane improves the adhesion properties of the surface compared to an adhesive layer. The additional opaque cover print is preferably in the form of a frame.

The laminated pane is preferably curved in one or more spatial directions, as is customary for motor vehicle panes, with typical radii of curvature being in the range from about 10 cm to about 40 m. However, the composite pane can also be flat, for example if it is intended as a pane for buses, trains or tractors.

The first thermoplastic intermediate layer and the second thermoplastic intermediate layer independently contain at least one thermoplastic polymer, preferably ethylene vinyl acetate (EVA), polyvinyl butyral (PVB) or polyurethane (PU) or mixtures or copolymers or derivatives thereof, particularly preferably PVB. The first thermoplastic intermediate layer and the second thermoplastic intermediate layer are typically independently formed from a thermoplastic film (bonding film). The thickness of the first thermoplastic intermediate layer and the second thermoplastic intermediate layer, independently of one another, is preferably from 0.2 mm to 2 mm, particularly preferably from 0.3 mm to 1 mm. The first thermoplastic intermediate layer and the second thermoplastic intermediate layer can each be formed by a single film or by more than one film. The first thermoplastic intermediate layer and/or the second thermoplastic intermediate layer can also be a film with functional properties, for example a film with acoustically damping properties.

The third thermoplastic intermediate layer independently contains at least one thermoplastic polymer, preferably ethylene vinyl acetate (EVA), polyvinyl butyral (PVB) or Polyurethane (PU) or mixtures or copolymers or derivatives thereof, particularly preferably PVB. The third thermoplastic intermediate layer is typically formed from a thermoplastic film (bonding film). As described above, the thickness of the third thermoplastic intermediate layer essentially corresponds to the thickness of the multilayer optical film. The third thermoplastic intermediate layer can be formed by a single film or by more than one film.

The individual foils of the optical multilayer film contain or consist preferably independently of one another of polyethylene (PE), polycarbonate (PC), polypropylene (PP), polystyrene, polybutadiene, polynitrile, polyester, in particular polyethylene terephthalate (PET), polyurethane (PU), polymethyl methacrylate (PMMA). ), polyacrylates, polyamides (PA), acrylonitrile-butadiene-styrene copolymers (ABS), styrene-acrylonitrile copolymers (SAN), acrylic ester-styrene-acrylonitrile copolymers (ASA), acrylonitrile-butadiene-styrene-polycarbonate mixtures ( ABS/PC) and/or their copolymers, cocondensates and/or mixtures. The individual foils of the optical multilayer film particularly preferably contain or consist of PET.

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 the inner pane can be clear and colorless, but also tinted or tinted. In a preferred embodiment, the total transmission through a laminated pane designed as a windshield (including the reflection layer) is greater than 70% in the main viewing area (light type A). The term total transmission refers to the procedure specified by ECE-R 43, Appendix 3, Section 9.1 for testing the light transmittance of motor vehicle windows. The outer pane and the inner pane can be unprestressed, partially prestressed or prestressed independently of one another. If at least one of the panes is to have a prestress, this can be a thermal or chemical prestress.

The thickness of the outer pane and the inner pane can vary widely and can thus be adapted to the requirements of the individual case. The outer pane and the inner pane preferably have thicknesses of from 0.5 mm to 5 mm, particularly preferably from 1 mm to 3 mm, very particularly preferably from 1.6 mm to 2.1 mm. For example, the outer pane has a thickness of 2.1 mm and the inner pane has a thickness of 1.6 mm. However, the outer pane or in particular the inner pane can also be thin glass with a thickness of, for example, 0.55 mm.

The laminated pane according to the invention can comprise one or more additional intermediate layers, in particular functional intermediate layers. An additional intermediate layer can be, in particular, an intermediate layer with acoustically damping properties, an intermediate layer that reflects infrared radiation, an intermediate layer that absorbs infrared radiation, an intermediate layer that absorbs UV radiation, an intermediate layer that is colored at least in sections and/or an intermediate layer that is tinted at least in sections. If several additional intermediate layers are present, these can also have different functions.

The invention also relates to a projection arrangement at least comprising a composite pane according to the invention and an imaging unit directed onto the section of the optical multilayer film designed as a concave mirror.

According to the invention, a projection arrangement is therefore also at least comprising a composite pane with an upper edge, a lower edge and two side edges, at least comprising an outer pane, a masking layer, a first thermoplastic intermediate layer, an optical multilayer film which has a section designed as a concave mirror, a second thermoplastic intermediate layer and an inner pane, wherein the multilayer optical film is arranged between the outer pane and the inner pane, the first thermoplastic intermediate layer is arranged between the outer pane and the multilayer optical film, the second thermoplastic intermediate layer is arranged between the multilayer optical film and the inner pane, the masking layer is arranged between the outer pane and the optical multilayer film is arranged in an area of the composite pane, and wherein at least the section of the optical multilayer film designed as a concave mirror is arranged in an area of the composite pane which, when looking through the composite pane perpendicularly, lies completely in the area in which the masking layer is arranged , an imaging unit directed onto the section of the optical multilayer film designed as a concave mirror.

The multilayer optical film can be constructed, for example, as described above.

In particular, the combination of the section of the optical multilayer film designed as a concave mirror with the masking layer behind it from the perspective of a vehicle occupant causes good visibility of the image in a projection arrangement according to the invention, even in external solar radiation and when using weak imaging units. Even under these circumstances, the image formed by the imaging unit appears bright and is excellent in visibility. This enables a reduction in the performance of the imaging unit and thus reduced energy consumption.

From the perspective of a vehicle occupant, the section of the optical multilayer film designed as a concave mirror is arranged spatially in front of the masking layer when viewed through the inner pane. The area of the laminated pane in which the section of the optical multilayer film designed as a concave mirror is arranged appears opaque as a result. The expression “looking through the laminated pane” means looking through the laminated pane, starting from the interior surface of the laminated pane. For the purposes of the present invention, “spatially in front” means that the section of the optical multilayer film designed as a concave mirror is arranged spatially further away from the outside surface of the outer pane than the masking layer. The masking layer is preferably widened at least in the area which overlaps with the section of the optical multilayer film designed as a concave mirror and in which the composite pane is used to display images. This means that the masking layer has a greater width in this area than in other sections, viewed perpendicularly to the closest section of the peripheral edge of the laminated pane. In this way, the masking layer can be adapted to the dimensions of the section of the optical multilayer film designed as a concave mirror.

The imaging unit of the projection arrangement emits light and is arranged in the vicinity of the interior-side surface of the inner pane in such a way that the imaging unit irradiates this surface, with the light coming from the concave mirror formed section of the multilayer optical film of the laminated pane is reflected. The section of the optical multilayer film designed as a concave mirror preferably reflects at least 10%, particularly preferably at least 50%, very particularly preferably at least 80% and in particular at least 90% of the incident light in a wavelength range of 400 nm to 700 nm and angles of incidence of 55° to 80° ° on the laminated pane. This is advantageous in order to achieve the greatest possible brightness of an image emitted by the imaging unit and reflected on the section of the optical multilayer film designed as a concave mirror.

The imaging unit is used to emit an image, so it can also be referred to as a projector, display device or image display device. For example, a display or another device known to a person skilled in the art can also be used as the imaging unit. The imaging unit is preferably a display, particularly preferably an LCD display, LED display, OLED display, MicroLED display or electroluminescent display, in particular an LCD display. Displays have a low installation height and can therefore be easily and space-savingly integrated into the dashboard of a vehicle. In addition, displays are much more energy-efficient to operate than other imaging units. The comparatively lower brightness of displays is completely sufficient in the combination according to the invention of the section of the optical multilayer film designed as a concave mirror and with the masking layer lying behind it. The radiation of the imaging unit preferably strikes the main plane of the section of the optical multilayer film designed as a concave mirror at an angle of incidence of 55° to 80°, preferably 62° to 77°. The angle of incidence is the angle between the incidence vector of the radiation of the image display device and the optical axis, i.e. the surface normal in the geometric center of the main plane of the section of the optical multilayer film designed as a concave mirror.

The imaging unit is arranged in particular within the simple focal length of the section of the optical multilayer film designed as a concave mirror. With such an arrangement, the virtual image is enlarged in the vertical direction compared to the image emitted by the imaging unit. For example, the virtual image has a size of 150% compared to the image emitted by the imaging unit. Thus, smaller imaging units can be used to generate a virtual image of a specific size. Smaller imaging units are characterized by lower energy consumption and also offer greater flexibility in imaging Dashboard placement. These are advantages of the projection arrangement according to the invention.

As described above, in the composite pane according to the invention, the main axis of the concave mirror can be inclined relative to the vertical of the composite pane, so that the main plane of the concave mirror does not run parallel to the main plane of the composite pane. In such embodiments, the angle of inclination of the composite pane differs from the angle of inclination of the main plane of the concave mirror. Such a decoupling of the angle of inclination of the composite pane from the angle of inclination of the main plane of the concave mirror allows more freedom when placing the imaging unit in the dashboard. This is a further advantage of the composite pane according to the invention and the projection arrangement according to the invention.

The preferred configurations of the composite pane according to the invention described above also apply correspondingly to the projection arrangement according to the invention comprising a composite pane according to the invention and an imaging unit and vice versa.

Also according to the invention is a method for producing a laminated pane according to the invention, at least comprising: a) providing an outer pane with an outside surface and an inside surface, a first thermoplastic intermediate layer, a second thermoplastic intermediate layer, an inside pane with an outside surface and an inside surface and a optical multilayer film which has a section designed as a concave mirror; b) Forming a layer stack in which the optical multilayer film is arranged between the outer pane and the inner pane, the first thermoplastic intermediate layer is arranged between the outer pane and the optical multilayer film, the second thermoplastic intermediate layer is arranged between the optical multilayer film and the inner pane, a masking layer is arranged between the outer pane and the optical multilayer film in an area of the composite pane and wherein at least the section of the optical multilayer film designed as a concave mirror is in an area of the composite pane is arranged, which lies completely in the region in which the masking layer is arranged when viewed perpendicularly through the laminated pane; c) connecting the stack of layers by lamination.

It goes without saying that the steps are carried out in the order a), b), c).

The optical multilayer film with a section designed as a concave mirror can, as described above, comprise a first film with an outside surface and an inside surface and a second film with an outside surface and an inside surface, the inside surface of the first sheet and the outside surface of the second film facing each other, and wherein in the section designed as a concave mirror the first film has an essentially plano-concave cross section, the second film has an essentially plano-convex cross section and a reflection layer for reflecting light is arranged between the first film and the second film . Such an optical multilayer film can be produced, for example, by producing the first film and the second film independently of one another by means of an injection molding process or thermoforming and then applying a reflective layer as a coating to the interior surface of the first film or to the exterior surface of the second film or a reflective layer in the form of a reflective foil is arranged between the first foil and the second foil. Optionally, an adhesive layer, for example made of an optically clear adhesive, can additionally be arranged over the entire surface between the first film and the second film.

In a further embodiment, the optical multilayer film with a section designed as a concave mirror can, as described above, comprise a multiplicity of films, wherein in the section designed as a concave mirror, a reflection layer for reflecting light is arranged in sections between two adjacent films and the reflection layers arranged in sections together define the concave mirror. Such an optical multilayer film can be produced, for example, by producing the films independently of one another by means of an injection molding process or thermoforming. The reflective layer can be introduced, for example, as a sectional coating of the individual foils. Optionally, an adhesive layer, for example made of an optically clear adhesive, can also be arranged over the entire surface between each two adjacent films. A reflection layer can be applied as a coating using well-known coating methods, such as magnetron sputtering or cold gas spraying.

The layer stack can be connected in step c) by means of lamination methods familiar to the person skilled in the art. 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. Alternatively, autoclave-free processes are also possible. Known vacuum bag or vacuum ring methods work, for example, at about 200 mbar and 80°C to 110°C. The stack of layers 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 discs 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 the layer stack being 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

In embodiments in which the optical multilayer film is only arranged in an area of the composite pane which, when viewed perpendicularly through the composite pane, lies completely in the area in which the masking layer is arranged, and the composite pane additionally has a third thermoplastic intermediate layer which contains the optical surrounds the multilayer film in a frame-like manner, step a) additionally comprises providing a third thermoplastic intermediate layer which has a recess and step b) additionally comprises arranging the third thermoplastic intermediate layer between the first and the second thermoplastic intermediate layer and arranging the optical multilayer film in the recess of the third thermoplastic intermediate layer.

The preferred configurations of the laminated pane according to the invention described above also apply correspondingly to methods for producing a laminated pane according to the invention. The invention also relates to the use of a composite pane according to the invention as a vehicle pane in means of transport for traffic on land, in the air or on water, in particular in motor vehicles and in particular as a windshield for a head-up display.

The invention is explained in more detail below with reference to drawings and exemplary embodiments. The drawings are schematic representations and not to scale. The drawings do not limit the invention in any way.

Show it:

Fig. 1 is a top view of an embodiment of an inventive

laminated pane,

Fig. 2 shows a cross section through the embodiment shown in Fig. 1,

Fig. 3 shows a section of the cross section shown in Fig. 2,

4 shows a cross section through a further embodiment of a laminated pane according to the invention,

Fig. 5 shows a section of the cross section shown in Fig. 4,

6 shows a cross section through a further embodiment of a laminated pane according to the invention,

Fig. 7 shows a section of the cross section shown in Fig. 6,

8 shows a cross section through a further embodiment of a laminated pane according to the invention,

FIG. 9 shows a section of the cross section shown in FIG. 8,

10 shows a cross section through a further embodiment of a laminated pane according to the invention,

Fig. 11 shows a section of the cross section shown in Fig. 10,

12 shows a cross section through a further embodiment of a laminated pane according to the invention,

Fig. 13 shows a section of the cross section shown in Fig. 12,

14 shows a cross section through a further embodiment of a laminated pane according to the invention,

FIG. 15 shows a section of the cross section shown in FIG. 14,

16 shows a cross section through a further embodiment of a laminated pane according to the invention,

FIG. 17 shows a section of the cross section shown in FIG. 16, 18 shows a cross-section of an embodiment of a multilayer optical film.

19 shows a section of a cross section of a further embodiment of a laminated pane according to the invention,

20 shows a cross section through an embodiment of a projection arrangement according to the invention, and

21 shows an exemplary embodiment of a method according to the invention using a flowchart.

FIG. 1 shows a top view of an embodiment of a composite pane 100 according to the invention and FIG. 2 shows the cross section through the composite pane 100 shown in FIG. 1 along the section line Y-Y'. The composite pane 100 shown in FIGS. 1 and 2 has an upper edge O, a lower edge U and two side edges S and comprises an outer pane 1 with an outside surface I and an inside surface II, an inner pane 6 with an outside surface III and a Interior surface IV, a first thermoplastic intermediate layer 3, a masking layer 2, an optical multilayer film 4 and a second thermoplastic intermediate layer 5. The optical multilayer film 4 is arranged between the outer pane 1 and the inner pane 6, the first thermoplastic intermediate layer 3 is between the outer pane 1 and optical multilayer film 4 and the second thermoplastic intermediate layer 5 is arranged between the optical multilayer film 4 and the inner pane 6 . In the embodiment shown in FIGS. 1 and 2, the outer pane 1, the first thermoplastic intermediate layer 3, the optical multilayer film, the second thermoplastic intermediate layer 5 and the inner pane 6 are arranged one above the other over their entire surface. The masking layer 2 is arranged between the outer pane 1 and the optical multilayer film 4 in a region of the laminated pane 100 . In the embodiment shown in FIGS. 1 and 2, the masking layer 2 is designed as an opaque masking print made of black enamel on the interior surface II of the outer pane 1 and is arranged in a peripheral edge area, which has a greater width in the area of the lower edge than in different sections.

The optical multilayer film 4 has a section A designed as a concave mirror, with this section A of the optical multilayer film 4 being arranged in an area of the laminated pane 100 which, when viewed perpendicularly through the laminated pane 100, lies entirely in the region in which the masking layer 2 is arranged. In FIG. 1, section A is surrounded by a white dotted line to clarify the position of section A. The concave mirror formed in section A is therefore not a spherical concave mirror as described in WO 2020/136646 A1, but a band-like concave mirror, for example a cylindrical concave mirror, which essentially extends over the entire width of the laminated pane 100.

The first thermoplastic intermediate layer 3 and the second thermoplastic intermediate layer 5 contain, for example, PVB and each have a thickness of 0.38 mm. The outer pane 1 consists, for example, of soda-lime glass and is 2.1 mm thick. The inner pane 6 consists, for example, of soda-lime glass and is 1.6 mm thick.

It is understood that the composite pane 100 can have any suitable geometric shape and/or curvature. Typically, the composite panel 100 is a curved composite panel.

FIG. 3 shows a section of the cross section shown in FIG. 2 of an embodiment of a laminated pane 100 according to the invention, in which the structure of the optical multilayer film 4 is shown in more detail. In the embodiment shown in Fig. 3, the optical multilayer film 4 has a first film 7 with an outside surface and an inside surface and a second film 8 with an outside surface and an inside surface and the inside surface of the first film 7 and the outside surfaces of the second film 8 face each other. In the section A designed as a concave mirror, the first film 7 has a plano-concave cross section and in the other sections a rectangular cross section. The second film 8 has a plano-convex cross section in section A designed as a concave mirror and a rectangular cross section in the remaining sections. In addition, a reflective layer 9 for reflecting light is arranged in the section A designed as a concave mirror between the first film 7 and the second film 8 .

The first film 7 and the second film 8 consist of PET, for example, and the optical multilayer film 4 has a total thickness of 2 mm, for example. Optionally, the first film 7 and the second film 8 can be connected to one another via an adhesive layer, for example in the form of an optically clear adhesive (OCA). The reflection layer 9 is, for example, a metallic layer with a thickness of 100 nm and contains aluminum.

FIG. 4 shows a cross section through a further embodiment of a composite pane 100 according to the invention and FIG. 5 shows a detail of the cross section shown in FIG. The embodiment shown in cross section in FIGS. 4 and 5 differs from that shown in FIGS. 2 and 3 only in that the masking layer 2 is not formed as an opaque masking print arranged on the interior-side surface II of the outer pane 1 , but as an opaque cover print arranged between the first thermoplastic intermediate layer 3 and the optical multilayer film 4 or as an opaque film arranged between the first thermoplastic intermediate layer 3 and the optical multilayer film 4 .

FIG. 6 shows a cross section through a further embodiment of a composite pane 100 according to the invention and FIG. 7 shows a detail of the cross section shown in FIG. The embodiment shown in cross section in FIGS. 6 and 7 differs from that shown in FIGS. 2 and 3 only in that the optical multilayer film 4 is not arranged over the entire surface between the outer pane 1 and the inner pane 6 but is only arranged in a region of the laminated pane 100 which, when viewed perpendicularly through the laminated pane 100, lies entirely in the region in which the masking layer 2 is arranged, and the laminated pane 100 additionally has a third thermoplastic intermediate layer 10, which contains the optical multilayer film 4 surrounded like a frame. The third thermoplastic intermediate layer 10 contains PVB, for example, and has a thickness which corresponds to the thickness of the optical multilayer film 4 . The third thermoplastic intermediate layer 10 has a recess in which the multilayer optical film 4 is accommodated.

FIG. 8 shows a cross section through a further embodiment of a composite pane 100 according to the invention and FIG. 9 shows a detail of the cross section shown in FIG. The embodiment shown in cross section in FIGS. 8 and 9 differs from that shown in FIGS. 6 and 7 only in that the masking layer 2 is not formed as an opaque covering print arranged on the interior-side surface II of the outer pane 1 , but as one arranged between the first thermoplastic intermediate layer 3 and the optical multilayer film 4 opaque cover print or as an opaque film arranged between the first thermoplastic intermediate layer 3 and the optical multilayer film 4 .

FIG. 10 shows a cross section through a further embodiment of a composite pane 100 according to the invention and FIG. 11 shows a detail of the cross section shown in FIG. The embodiment shown in cross section in FIGS. 10 and 11 differs from that shown in FIGS. 2 and 3 only in that the laminated pane 100 also has a high-index coating 11 arranged on the interior-side surface IV of the inner pane 6 a refractive index of at least 1.7 is arranged. The high-index coating 11 is formed, for example, as a single layer based on titanium oxide (refractive index 2.4) with a layer thickness of 70 nm, which is applied using a sol-gel method.

FIG. 12 shows a cross section through a further embodiment of a composite pane 100 according to the invention and FIG. 13 shows a detail of the cross section shown in FIG. The embodiment shown in cross section in FIGS. 12 and 13 differs from that shown in FIGS. 6 and 7 only in that the laminated pane 100 also has a high-index coating 11 arranged on the interior-side surface IV of the inner pane 6 a refractive index of at least 1.7 is arranged. The high-index coating 11 is formed, for example, as a single layer based on titanium oxide (refractive index 2.4) with a layer thickness of 70 nm, which is applied using a sol-gel method.

FIG. 14 shows a cross section through a further embodiment of a composite pane 100 according to the invention and FIG. 15 shows a detail of the cross section shown in FIG. The embodiment shown in cross section in FIGS. 14 and 15 differs from that shown in FIGS. 2 and 3 only in that the masking layer 2 is not formed as an opaque covering print arranged on the interior-side surface II of the outer pane 1 , but as an opaque colored area of the first thermoplastic intermediate layer 3 is formed.

FIG. 16 shows a cross section through a further embodiment of a composite pane 100 according to the invention and FIG. 17 shows a detail of the cross section shown in FIG. The embodiment shown in cross section in FIGS. 16 and 17 differs from that shown in FIGS. 6 and 7 only in that the Masking layer 2 is not formed as an opaque covering print arranged on the interior-side surface 11 of the outer pane 1, but is formed as an opaque colored area of the first thermoplastic intermediate layer 3.

Fig. 18 shows a cross section of an embodiment of a multilayer optical film 4. In the embodiment shown in Fig. 18, the multilayer optical film 4 has a first film 7, a second film 8 and three further films, which are given the reference numerals 12, 13 and 14 are provided. In section A designed as a concave mirror, a reflective layer 9 for reflecting light is arranged in sections between two adjacent films, and the reflective layers 9 arranged in sections together define the concave mirror.

The films 7, 8, 12, 13 and 14 are made of PET, for example, and the multilayer optical film 4 has a total thickness of 2 mm, for example. Optionally, adjacent foils of the foils 7, 8, 12, 13 and 14 can be connected to one another via an adhesive layer, for example in the form of an optically clear adhesive (OCA).

It goes without saying that in the case of laminated panes 100 according to the invention with a structure as shown in FIGS. 6, 8, 12 and 16, the optical multilayer film 4 does not have to be structured as shown in FIGS. 7, 9, 13 and 17, but also, for example as shown in FIG. 18. Even with composite panes 100 according to the invention with a structure as shown in FIGS. 2, 4, 10 and 14, the optical multilayer film 4 does not have to be constructed as shown in FIGS be formed films.

Fig. 19 shows a section of a further embodiment of a composite pane 100 according to the invention. The embodiment shown in Fig. 19 differs from that shown in Fig. 3 only in that the main axis of the concave mirror does not correspond to the vertical of the composite pane 100, but opposite Perpendicular of the laminated pane is inclined.

Fig. 20 shows a cross section through an embodiment of a projection arrangement 101 according to the invention. The projection arrangement 101 shown in Fig. 20 comprises a compound pane 100 and an imaging unit 15. The laminated pane 100 is designed as shown in Fig. 2 and has an upper edge O, a lower edge U and two side edges S and comprises an outer pane 1 with an outside surface I and an inside surface II, an inner pane 6 with an outside surface III and an interior-side surface IV, a first thermoplastic intermediate layer 3, a masking layer 2, an optical multilayer film 4 and a second thermoplastic intermediate layer 5. The optical multilayer film 4 is arranged between the outer pane 1 and the inner pane 6, the first thermoplastic intermediate layer 3 is between the Outer pane 1 and optical multilayer film 4 are arranged and the second thermoplastic intermediate layer 5 is arranged between the optical multilayer film 4 and the inner pane 6 . The outer pane 1, the first thermoplastic intermediate layer 3, the optical multilayer film 4, the second thermoplastic intermediate layer 5 and the inner pane 6 are arranged one on top of the other over their entire surface. The masking layer 2 is arranged between the outer pane 1 and the optical multilayer film 4 in a region of the laminated pane 100 . The masking layer 2 is in the form of an opaque masking print made of black enamel on the interior surface II of the outer pane 1 and is arranged in a peripheral edge area which is wider in the area of the lower edge than in different sections.

The optical multilayer film 4 has a section A designed as a concave mirror, with this section A of the optical multilayer film 4 being arranged in an area of the composite pane 100 which, when viewed perpendicularly through the composite pane 100, lies entirely in the area in which the masking layer 2 is arranged is.

For example, the laminated pane 100 is the windshield of a motor vehicle. The projection arrangement 101 has an imaging unit 15 . The imaging unit 15 serves to generate p-polarized light and/or s-polarized light (image information), which is directed onto the section A of the optical multilayer film 4 designed as a concave mirror and is reflected from there in the direction of the viewer, where it an observer, for example a driver, can be perceived. The section A of the optical multilayer film 4 designed as a concave mirror is designed to reflect the light of the imaging unit 15 , ie an image formed by the light of the imaging unit 15 . The light preferably hits the laminated pane 100 at an angle of incidence of 55° to 80°, in particular 62° to 77°. The imaging unit 15 is, for example, a display, in particular an LCD display.

FIG. 21 shows an exemplary embodiment of a method according to the invention using a flowchart.

In a first step S1, an outer pane 1 with an outside surface I and an inside surface II, a first thermoplastic intermediate layer 3, a second thermoplastic layer 5, an inner pane 6 with an outside surface III and an inside surface IV and an optical multilayer film 4 , which has a section A designed as a concave mirror.

In a second step S2, a stack of layers is formed in which the optical multilayer film 4 is arranged between the outer pane 1 and the inner pane 6, the first thermoplastic intermediate layer 3 is arranged between the outer pane 1 and the optical multilayer film 4, the second thermoplastic intermediate layer 5 is arranged between of the optical multilayer film 4 and the inner pane 6 is arranged, a masking layer 2 is arranged between the outer pane 1 and the optical multilayer film 4 in a region of the composite pane 100 and wherein at least the section A of the optical multilayer film 4 designed as a concave mirror is in a region of the composite pane 100 is arranged, which lies completely in the area in which the masking layer 2 is arranged when viewed perpendicularly through the laminated pane 100 .

In a third step S3, the stack of layers is connected by lamination. Example:

In a projection arrangement according to the invention with the following parameters, which includes a composite pane according to the invention and an imaging unit, the virtual image has a size of 150% compared to the image emitted by the imaging unit.

Radius of curvature of the section of the optical multilayer film designed as a concave mirror: 400 mm

Distance eye point of the viewer - apex of the concave mirror: 800 mm

Distance from the apex of the concave mirror - virtual image: 215 mm

Distance from the vertex of the concave mirror to the imaging unit: 128.8 mm

Angle of incidence onto the section of the optical multilayer film designed as a concave mirror: 50°

Angle of incidence on the laminated pane: 62°

In the context of this invention, the term “apex of the concave mirror” designates the intersection point of the central optical path in the geometric center of the main plane of the concave mirror.

With this projection arrangement according to the invention, an observer sees an image that is 66.6 mm high and emitted by the transmitting unit as a virtual image with a height of 100 mm.

Reference list:

100 Composite Disc

101 projection arrangement

1 outer pane

2 masking layer

3 first thermoplastic intermediate layer

4 optical multilayer film

5 second thermoplastic intermediate layer

6 inner pane

7 first slide

8 second slide

9 reflective layer

10 third thermoplastic intermediate layer

11 high index coating

12 slide

13 slide

14 slide

15 imaging unit

O Upper edge of composite pane 100

U Lower edge of composite pane 100

S side edge of composite pane 100

I outside surface of the outer pane 1

II interior surface of the outer pane 1

III Outside surface of the inner pane 6

IV interior surface of the inner pane 6

A section of the optical multilayer film 4 designed as a concave mirror

Y-Y' line of intersection

Claims

Claims Composite pane (100) with an upper edge (O), a lower edge (U) and two side edges (S), at least comprising

- an outer pane (1) with an outside surface (I) and an inside surface (II),

- a masking layer

(2),

- a first thermoplastic intermediate layer (3),

- an optical multilayer film (4) which has a section (A) designed as a concave mirror,

- a second thermoplastic intermediate layer (5), and

- an inner pane (6) with an outside surface (III) and an inside surface (IV), wherein the optical multilayer film (4) is arranged between the outer pane (1) and the inner pane (6), the first thermoplastic intermediate layer

(3) is arranged between the outer pane (1) and the optical multilayer film (4), the second thermoplastic intermediate layer (5) is arranged between the optical multilayer film (4) and the inner pane (6), the masking layer (2) between the outer pane (1) and the optical multilayer film (4) is arranged in an area of the composite pane (100), and wherein at least the section (A) of the optical multilayer film (4) designed as a concave mirror is arranged in an area of the composite pane (100) which when viewed perpendicularly through the laminated pane (100) lies entirely in the region in which the masking layer (2) is arranged. Laminated pane (100) according to claim 1, wherein the optical multilayer film (4) is arranged over the entire surface between the outer pane (1) and the inner pane (6). Laminated pane (100) according to claim 1, wherein the optical multilayer film (4) is arranged in an area of the laminated pane (100) which, when viewed perpendicularly through the laminated pane (100), lies completely in the area in which the masking layer (2) is arranged and the laminated pane (100) additionally has a third thermoplastic intermediate layer (10) which surrounds the optical multilayer film (4) like a frame.

4. Laminated pane (100) according to one of claims 1 to 3, wherein the optical multilayer film (4) has a first film (7) with an outside surface and an inside surface and a second film (8) with an outside surface and an inside surface and the interior surface of the first film (7) and the outside surface of the second film (8) face each other, and wherein in the section (A) designed as a concave mirror, the first film (7) has an essentially plano-concave cross section, which second film (8) has an essentially plano-convex cross-section and a reflection layer (9) for reflecting light is arranged at least in the section (A) designed as a concave mirror between the first film (7) and the second film (8).

5. Laminated pane (100) according to one of claims 1 to 3, wherein the optical multilayer film (4) comprises a plurality of films (7, 8, 12, 13, 14), in the section (A) designed as a concave mirror between two adjacent foils, a reflection layer (9) for reflecting light is arranged in sections and the reflection layers (9) arranged in sections together define the concave mirror.

6. Laminated pane (100) according to claim 4 or 5, wherein the reflection layer (9) reflects at least 10%, preferably at least 50%, particularly preferably at least 80% and in particular at least 90% of visible light.

7. Composite pane (100) according to any one of claims 4 to 6, wherein the reflection layer (9) has an average transmission in the visible spectral range of at most 50%, in particular less than 10%.

8. Laminated pane (100) according to one of Claims 1 to 7, in which the masking layer (2) is designed in the form of a frame all the way around and in particular in a section which overlaps the section (A) of the optical multilayer film (4) designed as a concave mirror , has a greater width than in different sections.

9. Laminated pane (100) according to one of claims 1 to 8, wherein the masking layer (2) is formed as an opaque cover print arranged on the interior-side surface (II) of the outer pane (1) or the masking layer (2) as a layer between the first thermoplastic intermediate layer (3) and the optical multilayer film (4) or as an opaque film arranged between the first thermoplastic intermediate layer (3) and the optical multilayer film (4).

10. Laminated pane (100) according to any one of claims 1 to 8, wherein the masking layer (2) is formed as an opaque colored region of the first thermoplastic intermediate layer (3).

11. Laminated pane (100) according to one of claims 1 to 10, wherein a high-index coating (11) with a refractive index of at least 1.7 is arranged on the interior-side surface (IV) of the inner pane (6).

12. Composite pane (100) according to any one of claims 1 to 11, wherein the main axis of the concave mirror is inclined relative to the vertical of the composite pane (100).

13. projection arrangement (101) at least comprising

- a composite pane (100) according to any one of claims 1 to 12,

- an imaging unit (15) directed towards the section (A) of the optical multilayer film (4) designed as a concave mirror.

14. A method for producing a composite pane (100) according to any one of claims 1 to 12, at least comprising a) providing an outer pane (1) with an outside surface (I) and an inside surface (II), a first thermoplastic intermediate layer (3) , a second thermoplastic intermediate layer (5), an inner pane (6) with an outside surface (III) and an inside surface (IV) and an optical multilayer film (4) which has a section (A) designed as a concave mirror; b) formation of a layer stack in which the optical multilayer film (4) is arranged between the outer pane (1) and the inner pane (6), the first thermoplastic intermediate layer (3) is arranged between the outer pane (1) and the optical multilayer film (4). the second thermoplastic intermediate layer (5) is arranged between the optical multilayer film (4) and the inner pane (2), a masking layer (2) between the outer pane (1) and the optical multilayer film (4) in a region of the composite pane (100 ) is arranged and at least as a concave mirror formed section (A) of the optical multilayer film (4) is arranged in a region of the laminated pane (100) which, when viewed perpendicularly through the laminated pane (100), lies entirely in the region in which the masking layer (2) is arranged; c) connecting the stack of layers by lamination. Use of a laminated pane (100) according to one of Claims 1 to 12 as a vehicle pane in means of transport for traffic on land, in the air or on water, in particular in motor vehicles and in particular as a windscreen for a head-up display.