Laminated pane with masking layer and electrically switchable functional membrane - Patent Application 20070122997

Abstract

a thermoplastic intermediate layer; an inner pane having an outer surface and an inner surface; at least one masking layer arranged between the outer pane and the inner pane; at least one electrically switchable functional membrane that can be switched between a first switching state having a relatively low light transmittance and a second switching state having a relatively high light transmittance by application of an operating voltage, the functional membrane being arranged so as to be immediately adjacent to the masking layer or to overlap an opening in the masking layer when viewed vertically through the laminated pane, the masking layer and the electrically switchable functional membrane being arranged within the area of ​​the laminated pane; and at least one reflective layer for reflecting light, present on the outer surface and / or the inner surface of the inner pane, the reflective layer being arranged completely within the area of ​​the laminated pane where the masking layer and the electrically switchable functional membrane are arranged when viewed vertically through the laminated pane.

Description

[Technical Field]

[0001] The present invention relates to a laminated pane with a partially applied reflective layer and a combination of a masking layer and an electrically switchable functional film, to a method for producing and using the same, and to a projection installation. [Background technology]

[0002] Modern automobiles are increasingly being equipped with so-called head-up displays (HUDs). Typically, a projector is located in the dashboard area, which projects an image onto the windshield, where it is reflected, and the driver perceives it as a virtual image behind the windshield. In this way, important information, such as the current travel speed or navigation messages and warnings, can be projected into the driver's field of vision, allowing the driver to perceive this without having to take their eyes off the road. Head-up displays can therefore make a significant contribution to improving road safety.

[0003] However, head-up displays often face the challenge of requiring a high degree of transparency, typically at least 70%, for the windshield area used to reflect the light projected by the projector. Therefore, the projector's reflected light overlaps with light from the external environment, which can reduce the contrast of the virtual image depending on the lighting conditions, ultimately impairing the driver's visual perception. Satisfactory visual perception of safety-related information, particularly lane assistance, speed indicators, and motor rotation speed, must be guaranteed under all weather and lighting conditions. Therefore, it is desirable to provide a projection system based on head-up display technology that is relatively easy to achieve good visibility without generating undesirable secondary images and while maintaining sufficient brightness and contrast of the displayed image information. To achieve this, it is necessary to increase the contrast of the reflective area of ​​the windshield. This can be achieved, for example, by making the background of the reflective area significantly or completely opaque. Such a solution requires applying a reflective layer only to a locally limited area of ​​the windshield.

[0004] Metal coatings are typically applied to glass panes by sputtering, particularly magnetron sputtering. During sputtering, atoms are ejected from a target by bombarding it with ions. Physical vapor deposition coats the glass pane with atoms ejected from the target in a vacuum chamber. The atoms are guided by an electric field through the chamber toward the glass pane. The atoms move from a cathode, where the target is located, toward an anode. A layer is formed on the glass pane by placing the glass pane between the cathode and the anode. In magnetron sputtering, an additional magnetic field is placed behind the cathode, which accelerates the layer growth and results in a denser, i.e., less porous, layer. Methods for using sputtering to coat glass panes are known, for example, from WO 9900528, DE 10126868, and WO 2017198363.

[0005] Magnetron sputtering is also suitable for coating panes because, unlike many other coating techniques, it can be used when the glass panes are curved, as is the case for panes intended for the automotive sector, for example. Selective coating of only certain surface areas can be achieved, for example, by masking the areas not to be coated.

[0006] Cold gas spraying is also a suitable glass pane coating method well known to those skilled in the art, in which powder is applied to the carrier at very high speeds. Coating methods using cold gas spraying are known, for example, from WO 2010 / 003396, EP 3845685 and EP 2902530.

[0007] The reflective layer in the masking layer region allows for good visibility of the virtual image with high contrast and adequate brightness. Conventionally, the dimensions of the masking layer and the reflective layer are determined at the time of manufacturing, so it has been impossible to change the opaque region in practice. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 9900528 [Patent Document 2] German Patent No. 10126868 [Patent Document 3] International Publication No. 2017198363 [Patent Document 4] International Publication No. 2010 / 003396, [Patent Document 5] European Patent Application Publication No. 3845685 [Patent Document 6] European Patent Application Publication No. 2902530 Summary of the Invention [Problem to be solved by the invention]

[0009] The object of the present invention is to provide an improved laminated pane with a locally applied reflective layer that is able to overcome the aforementioned drawbacks, in particular that the laminated pane should be easy to manufacture and reliable in continuous industrial production. [Means for solving the problem]

[0010] The object is achieved according to the invention by a laminated pane as defined in claim 1. Preferred embodiments are evident from the dependent claims.

[0011] A laminated pane according to the present invention comprises an outer pane, a thermoplastic intermediate layer, at least one masking layer, and an inner pane, the thermoplastic intermediate layer being disposed between the outer pane and the inner pane, and the masking layer being disposed between the outer pane and the inner pane.

[0012] The laminated pane further comprises at least one electrically switchable functional membrane comprising a functional layer switchable by application of an operating voltage between a first switching state having a relatively low light transmittance and a second switching state having a relatively high light transmittance. According to the invention, the electrically switchable functional membrane is arranged immediately adjacent to the masking layer or overlapping an opening in the masking layer when viewed vertically through the laminated pane, wherein the masking layer and the switchable functional membrane are arranged within the area of ​​the laminated pane.

[0013] Furthermore, the laminated pane comprises at least one reflective layer for light reflection on the outer surface and / or inner surface of the inner pane, wherein this reflective layer is positioned entirely within the aforementioned area of ​​the laminated pane in which the masking layer and the switchable functional membrane are positioned when viewed vertically through the laminated pane.

[0014] When the electrically switchable functional membrane is directly adjacent to the masking layer, the dimensions of the opaque region of the laminated pane defined by the masking layer are freely expandable. The opaque region of the laminated pane is preferably tightly expanded by the electrically switchable functional membrane when in the first switching state. When the electrically switchable functional membrane is arranged to overlap the opening of the masking layer, the dimensions of the opaque region of the laminated pane defined by the masking layer are freely expandable, and the opening of the masking layer can be made opaque by the electrically switchable functional membrane when in the first switching state. For this purpose, the electrically switchable functional membrane completely covers the opening of the masking layer when viewed vertically through the laminated pane. Thus, in the first switching state, the electrically switchable functional membrane complements the masking layer to expand the opaque region of the laminated pane. In other words, the size of the opaque region of the laminated pane can be freely changed by using the masking layer in combination with the electrically switchable functional membrane. In a first switching state of the electrically switchable functional membrane, the opaque areas of the laminated pane, when viewed perpendicularly through the laminated pane, are created by a combination of the opaque areas of the masking layer and the opaque areas of the electrically switchable functional membrane, and in a second switching state, the opaque areas of the laminated pane are formed solely by the masking layer.

[0015] The electrically switchable functional film advantageously allows the dimensions of the opaque region of the laminated pane to be changed, i.e., the opaque region is enlarged, when the electrically switchable functional film is in a first switching state with a relatively low light transmittance. Conversely, the dimensions of the opaque region of the laminated pane can be reduced to the dimensions of the masking layer, i.e., the opaque region of the laminated pane is reduced, when the electrically switchable functional film is in a second switching state with a relatively high light transmittance. In this way, the size of the opaque region of the laminated pane can be freely enlarged or reduced by electrically switching the electrically switchable functional film, and thus can be specifically adapted to the relevant requirements. For example, in certain driving situations of a car, such as parking, it may be desirable to maximize the transparent region of the windshield. Meanwhile, in other driving situations, such as when the vehicle is stationary or autonomously driving, it may be desirable to maximize the opaque region and display as much information as possible with high contrast.

[0016] The electrically switchable functional film thus acts to increase the size of the opaque region of the laminated pane when the electrically switchable functional film is in a first switch state, while leaving the opaque region unchanged when the electrically switchable functional film is in a second switch state, such that the switchable functional film is opaque to visible light in the first switch state and transparent in the second switch state.

[0017] In the present invention, "transparent" is understood to mean a visible light transmittance of more than 30%. "Opaque" is therefore understood to mean a light transmittance of less than 5%, preferably less than 1.5%, in particular 0.1% or less, for example 0%. Particularly preferably, the switchable functional film has a light transmittance of less than 1.5% in the first switching state and a light transmittance of more than 30% in the second switching state. The electrically switchable functional film is opaque in the first switching state with low optical transparency and transparent in the second switching state with high optical transparency.

[0018] Electrically switchable functional membranes with variable optical transparency are well known to those skilled in the art and are commercially available. These functional membranes are generally planar electro-optical functional elements that comprise a functional layer (active layer) between two surface electrodes, and the optical transparency of the functional layer can be electrically controlled. That is, the optical transparency of the functional membrane or functional layer can be controlled by applying a voltage (operating voltage), where the functional layer as a whole is opaque in the absence of a voltage and transparent in the presence of a voltage. In this way, the applied voltage can be used to control the transmittance of visible light through the electro-optical functional element, but adjusting the optical properties in this way does not generally allow for independent illumination of the laminated pane.

[0019] The electrical contact of each functional layer is usually made by a busbar, which is applied to the edge region of the functional layer and electrically contacts each functional layer, and a voltage is applied by connecting the busbar to an external power source, typically through a flat conductor attached to the busbar, to switch the functional layer.

[0020] In principle, any electrically switchable functional film can be used, whose optical transparency can be changed by applying an operating voltage and which can be switched between an opaque and a transparent switching state. The electrically switchable functional film is preferably a guest-host functional film, an electrochromic functional film, an SPD functional film, or a PDLC functional film. Such functional films can be easily laminated into the laminate pane.

[0021] In particular, electro-optical functional films based on the so-called "guest-host" effect with a liquid crystal-based functional layer are one of the important possibilities for realizing electro-optical switching functions in laminated panes in a simple, space-saving, cost-effective, and reliable manner during application. Hereinafter, electro-optical functional films based on the "guest-host" effect with a liquid crystal-based functional layer will be referred to as "guest-host functional films" for convenience. Guest-host functional films typically contain a nematic liquid crystal (host) doped with an additive (guest), where dichroic dye molecules that anisotropically absorb light are used as the additive. Because the additive molecules have an elongated morphology, their orientation can be controlled by the orientation of the liquid crystal molecules, i.e., the host, which is achieved in practice by applying an electric field to the liquid crystal. In this way, the optical transparency of the guest-host functional film can be very precisely controlled by an external electric field. Guest-host functional films with a functional layer made of a liquid crystal material with an embedded additive are well known to those skilled in the art, and therefore need not be discussed in further detail here. The guest-host functional film is commercially available under the name of "light control film," for example, from Dai Nippon Print Co., Ltd. (Japan) under the product name LCF005(EU).

[0022] Electrochromic functional membranes are known, for example, from US Patent Application Publication No. 20120026573 and WO 2012007334. SPD functional membranes (SPD = suspended particle device) are known, for example, from EP 0 876 608 and WO 2011033313. PDLC functional membranes (PDLC = polymer dispersed liquid crystal) are known, for example, from DE 102008026339. Such functional membranes are frequently used in the continuous industrial production of laminated panes and are well known to those skilled in the art, so they do not need to be discussed in further detail here.

[0023] The laminated pane according to the invention is preferably provided in a window opening of a vehicle to separate the interior from the exterior environment. Within the meaning of the present invention, the term "inner pane" refers to the pane of the laminated pane facing the interior of the vehicle. An outer pane is understood to mean the pane facing the exterior environment.

[0024] The laminated pane has in particular an upper edge, a lower edge and two side edges extending therebetween. The upper edge is understood to mean the edge intended to face upwards in the installed position. The lower edge is understood to mean the edge intended to face downwards in the installed position. In the case of a windshield, the upper edge is often also called the roof edge and the lower edge is called the motor edge.

[0025] The outer pane and the inner pane each have an outer surface, an inner surface, and a peripheral side edge extending therebetween. Within the meaning of the present invention, the outer surface is understood to mean the major surface intended to face the external environment when installed. Within the meaning of the present invention, the inner surface is understood to mean the major surface intended to face the interior when installed. The inner surface of the outer pane and the outer surface of the inner pane face each other and are joined to each other by a thermoplastic intermediate layer. The outer surface of the outer pane is designated as face I, and the inner surface of the outer pane is designated as face II. The outer surface of the inner pane is designated as face III. The inner surface of the outer pane and the outer surface of the inner pane face each other.

[0026] According to the present invention, at least one reflective layer for reflecting light is disposed on the outer surface and / or the inner surface of the inner pane. Thus, a single reflective layer may be disposed on the outer surface of the inner pane or on the inner surface of the inner pane. Alternatively, two reflective layers may be disposed on the outer surface of the inner pane and on the inner surface of the inner pane.

[0027] When the laminated pane is installed in a vehicle, the reflective layer is at a shorter distance from the interior of the vehicle than the masking layer, so that the imaging unit of the projection equipment located inside the vehicle has a direct view of the reflective layer, and the reflective layer can reflect the light (virtual image) emitted by the imaging unit.

[0028] The reflective layer is arranged in a region of the laminated pane that, when viewed vertically through the laminated pane, is completely located within the region in which the masking layer and the electrically switchable functional film are arranged. Therefore, the reflective layer is arranged so that it covers or overlaps the combination of the masking layer and the electrically switchable functional film when viewed vertically through the laminated pane or in direct projection through the laminated pane. In other words, the reflective layer does not have any portions that do not overlap the combination of the masking layer and the electrically switchable functional film. That is, the reflective layer is formed only in a location that is located in front of the combination of the masking layer and the electrically switchable functional film when viewed from the inside of the laminated pane. This ensures high contrast and brightness, and thus good visibility of the virtual image reflected by the reflective layer, especially when the electrically switchable functional film is in the first switching state (opaque).

[0029] The reflective layer serves to reflect light. The reflective layer is preferably opaque or partially transparent, which in the present invention is understood to mean that the reflective layer preferably has an average transmittance (according to ISO 9050:2003) of at most 80%, particularly preferably at most 50%, and in particular less than 10% within the visible spectrum. 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 striking it. The reflective layer preferably reflects p-polarized and s-polarized light in equal proportions, although it is also possible to reflect p-polarized and s-polarized light to different degrees. In one embodiment, the light reflected by the reflective layer mainly contains p-polarized light, so that the virtual image can be clearly seen even when using s-polarized sunglasses. Methods for measuring light reflection are known to those skilled in the art. In this case, a light source (standard illuminant A) and a detector are positioned on the same side of the reflective layer, and the reflected light is detected by the detector. For example, light from the light source strikes the reflective surface at an angle of 80° relative to the normal.

[0030] The light reflected by the reflective layer is preferably visible light, i.e., light in the wavelength range of approximately 380 nm to 780 nm. The reflective layer preferably has a high and uniform reflectivity (at various angles of incidence) for p-polarized and / or s-polarized radiation, thereby ensuring the display of an intense and color-neutral image.

[0031] References to polarization direction are relative to the plane of incidence of the radiation on the laminate pane. P-polarized radiation refers to radiation whose electric field oscillates in the plane of incidence. S-polarized radiation refers to radiation whose electric field oscillates perpendicular to the plane of incidence. The plane of incidence is spanned by the incidence vector and the surface normal of the laminate pane at the geometric center of the illuminated area.

[0032] In other words, the polarization, i.e. in particular the proportion of p-polarized and s-polarized radiation, is determined at a point in the area illuminated by the image display device, preferably at the geometric center of the illuminated area. Since the laminated pane may be curved (for example when formed as a windshield), which affects the plane of incidence of the radiation of the image display device, polarization components that deviate slightly from it may occur in other areas, which is unavoidable for physical reasons.

[0033] In one preferred embodiment of the present invention, the reflective layer is a metallic layer, ie a layer comprising or consisting of a metal.

[0034] The reflective layer preferably contains at least one metal selected from the group consisting of aluminum, magnesium, tin, indium, titanium, tantalum, niobium, nickel, copper, chromium, cobalt, iron, manganese, zirconium, cerium, scandium, yttrium, silver, gold, platinum, palladium, ruthenium, or mixtures thereof. Aluminum, titanium, and / or nickel are preferred because they can have high reflectivity for p-polarized or s-polarized light. Aluminum is particularly preferred.

[0035] The reflective layer preferably has a thickness of 10 nm (nanometers) to 100 μm (micrometers), particularly preferably 50 nm to 50 μm, and in particular 100 nm to 5 μm.

[0036] In a particularly preferred embodiment, the reflective layer is a thin film stack, i.e., a coating comprising a sequence of individual thin layers. This thin film stack includes one or more conductive layers based on nickel, titanium, and / or aluminum. The conductive layers based on nickel, titanium, and / or aluminum provide IR reflection and electrical conductivity in addition to the basic reflective properties of the reflective layer. The conductive layers are based on nickel, titanium, and / or aluminum. The conductive layers preferably contain at least 90% by weight of nickel, titanium, and / or aluminum, particularly preferably at least 99% by weight of aluminum, and very particularly preferably at least 99.9% by weight of nickel, titanium, and / or aluminum. The aluminum, nickel, and / or titanium-based layers can be doped, for example, with 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 metal coatings has proven particularly advantageous in reflecting light. Aluminum, nickel, and / or titanium are significantly cheaper than many other metals, such as gold and silver. The individual layers of the thin film stack preferably have a thickness of 10 nm to 1 μm. The thin film stack preferably has 2 to 20 individual layers, in particular 5 to 10 individual layers.

[0037] As mentioned above, at least one masking layer is disposed within the laminated pane according to the present invention. The masking layer is preferably disposed within an edge region of the laminated pane, typically adjacent to the pane edge of the pane. This configuration has a significant advantage when the laminated pane is used as a windshield within a vehicle, since the masking layer, when disposed within the edge region, is outside the driver's primary field of vision.

[0038] The masking layer is preferably disposed adjacent to at least the bottom edge, such that when the laminated pane is viewed, it results in a rectangular opaque strip disposed along the bottom edge.

[0039] In one particular embodiment of the laminated pane according to the invention, the masking layer is designed to extend in a frame-like manner along the periphery. In the area where the reflective layer overlaps the masking layer, the frame-like masking layer is provided with, for example, a widened portion, i.e., this widened portion is wider (in the dimension perpendicular to the extension) than the remaining area. In this way, the masking layer (in combination with the electrically switchable functional film) can be appropriately adapted to the dimensions of the reflective layer. In one embodiment, the masking layer is designed to extend in a frame-like manner along the periphery, and in particular in the area where the reflective layer overlaps, it has a wider width than the remaining area.

[0040] For example, the reflective layer may have a substantially rectangular shape extending to an area near the bottom edge between the two side edges, for example, the edges of the reflective layer do not reach the side edges and the bottom edge, but instead are spaced therefrom, for example, 2 cm to 5 cm.

[0041] The masking layer in the present invention is a layer that prevents light from being seen through the laminated pane. In this case, less than 5%, preferably less than 1.5%, particularly 0.1% or less of the light in the visible spectrum is transmitted through the masking layer. Therefore, the masking layer is an opaque masking layer, preferably a black masking layer. The method for measuring light transmittance is known to those skilled in the art. Here, a light source (standard light source A) is placed on one side of the masking layer, and a detector is placed on the other side of the masking layer, and the transmitted light is detected by the detector.

[0042] The masking layer is preferably a coating made up of one or more layers. Alternatively, the masking layer may be a colored area of ​​a thermoplastic interlayer. According to a preferred embodiment of the laminated pane, the masking layer consists of a single layer. This has the advantage that the production of the laminated pane is particularly simple and cost-effective, since only a single layer needs to be formed for the masking layer. The masking layer is in particular an opaque masking print made of dark, preferably black, enamel.

[0043] Advantageously, the masking layer is designed as an opaque masking print, in particular made of dark, preferably black, enamel, arranged on the inner surface (surface II) of the outer pane. Alternatively or additionally, the masking layer is designed as an opaque masking print, in particular made of dark, preferably black, enamel, arranged on the outer surface (surface III) of the inner pane. In particular, a first opaque masking print can be arranged on the inner surface (surface II) of the outer pane and a second opaque masking print can be arranged on the outer surface (surface III) of the inner pane.

[0044] In an alternative embodiment, the masking layer is designed as an opaque colored area of ​​the thermoplastic interlayer, hi one embodiment, the thermoplastic interlayer is integrally formed and is opaque colored in certain areas.

[0045] The masking layer formed as an opaque colored area of ​​the thermoplastic intermediate layer can also be realized by using a thermoplastic intermediate layer composed of an opaque thermoplastic functional film and a transparent thermoplastic functional film. The transparent functional film and the opaque functional film are made of the same plastic or preferably contain the same plastic. The materials on which the opaque functional film and the transparent functional film are formed are those described for the thermoplastic intermediate layer. The opaque functional film is preferably a colored functional film that can have various colors, especially black.

[0046] In one embodiment of the laminated pane according to the invention, a reflective layer for light reflection is arranged on the inner surface of the glass pane, and a protective layer is arranged on this reflective layer. The protective layer is preferably transparent and is applied planarly, particularly conformally, to the reflective layer. The protective layer is preferably a polymer based on polyacrylate, polyoxime, alkyd resin, polyurethane, or a mixture thereof. The thickness of the protective layer is preferably 50 nm to 10 μm, particularly preferably 100 nm to 5 μm. The protective layer protects the reflective layer from mechanical damage, such as scratches. The protective layer can also serve to improve the durability of the reflective layer.

[0047] In a preferred embodiment of the present invention, the protective layer is an easy-to-clean and / or "fingerprint-resistant" layer. In the present invention, "easy-to-clean" layer is understood to mean that dirt on the protective layer, for example in the form of fingerprints, grease spots, or dirt particles, can be removed from the protective layer with the use of a cloth, preferably a microfiber cloth. Thus, the use of oil-soluble or abrasive cleaning agents or, for example, alcohol-based solvents for cleaning the protective layer is largely avoided. In the present invention, "fingerprint-resistant" layer is understood to mean a layer on which fingerprints adhering to the protective layer are barely or not visually perceptible. The term "fingerprint" particularly refers to the oil-containing residue of a human finger that remains on a surface when touching it and which may be unaesthetic.

[0048] The laminated pane is preferably curved in one or more spatial directions, as is common in automotive panes, with typical radii of curvature ranging from about 10 cm to about 40 mm, but may also be flat, for example when the laminated pane is provided as a pane for a bus, train, or tractor.

[0049] The thermoplastic intermediate layer joining the outer pane to the inner pane comprises at least one thermoplastic polymer, preferably ethylene vinyl acetate copolymer (EVA), polyvinyl butyral (PVB), or polyurethane (PU), or a mixture, copolymer, or derivative thereof, and particularly preferably PVB. The thermoplastic intermediate layer is typically formed from a thermoplastic functional film (joining film). The thickness of the thermoplastic intermediate layer is preferably 0.2 mm to 2 mm, particularly preferably 0.3 mm to 1 mm, for example, 760 μm. The thermoplastic intermediate layer may be formed from a single film or two or more films. The thermoplastic intermediate layer may also be a film with functional properties, such as acoustic damping properties.

[0050] The outer and inner panes preferably comprise or consist of glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass, aluminosilicate glass, or transparent plastic, preferably rigid transparent plastic, in particular polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, polystyrene, polyamide, polyester, polyvinyl chloride and / or mixtures thereof.

[0051] The outer and inner panes may be clear, tinted, or colored. In a preferred embodiment, the total light transmittance of the entire windshield is greater than 70% in the primary see-through area (light type A). The term "total light transmittance" refers to the method defined in ECE-R 43, Annex 3, Section 9.1 for testing the light transmittance of automobile panes. The outer and inner panes may be, independently of one another, unprestressed, partially prestressed, or prestressed. If at least one pane is prestressed, this may be thermal or chemical prestressing.

[0052] The thickness of the outer and inner panes can vary widely and can be adapted to the requirements of each individual case. The outer and inner panes preferably have a thickness of 0.5 mm to 5 mm, particularly preferably 1 mm to 3 mm, and very particularly preferably 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, and in particular the inner pane, can also be thin glass, for example, having a thickness of 0.55 mm.

[0053] The laminated pane according to the invention may comprise one or more additional interlayers, in particular functional interlayers. The additional interlayers may in particular be interlayers with acoustic damping properties, interlayers that reflect infrared radiation, interlayers that absorb infrared radiation, interlayers that absorb ultraviolet radiation, at least partially colored layers, and / or at least partially tinted interlayers. If several additional interlayers are present, they may also have different functions.

[0054] The invention also relates to a projection installation comprising a laminated pane according to the invention and an imaging unit directed towards the reflective layer.

[0055] Therefore, the present invention further provides a projection installation, comprising: - a laminated pane comprising an outer pane with an outer surface and an inner surface, a thermoplastic intermediate layer, an inner pane with an outer surface and an inner surface, at least one masking layer arranged between the outer pane and the inner pane, at least one electrically switchable functional membrane switchable between a first switching state having a relatively low light transmittance and a second switching state having a relatively high light transmittance by application of an operating voltage, the electrically switchable functional membrane being arranged so as to be immediately adjacent to the masking layer or so as to overlap an opening in the masking layer when viewed vertically through the laminated pane, wherein the masking layer and the electrically switchable functional membrane are arranged within the area of ​​the laminated pane, and at least one reflective layer for light reflection present on the outer and / or inner surface of the inner pane, the reflective layer being arranged completely within the area of ​​the laminated pane where the masking layer and the electrically switchable functional membrane are arranged when viewed vertically through the laminated pane, - an imaging unit directed at the reflective layer; A projection installation is also provided.

[0056] The reflective layer is provided with a masking layer behind the reflective layer as viewed by the vehicle occupants, and the masking layer is combined with an electrically switchable functional film to ensure good visibility of the virtual image in the projection system according to the present invention, even in the presence of outdoor sunlight and when using a low-light imaging unit. Even under these conditions, the image generated by the imaging unit appears bright and fully visible. This allows for reduced power consumption of the imaging unit and thus reduced energy consumption.

[0057] From the perspective of a vehicle occupant, when viewed through the inner pane, the reflective layer is spatially positioned in front of the combination of the masking layer and the electrically switchable functional membrane. As a result, the area of ​​the laminated pane where the reflective layer is positioned appears opaque. The expression "when viewed through the laminated pane" is understood to mean starting from the inner surface of the laminated pane and looking through the laminated pane. As used herein, the expression "spatially in front of" is understood to mean that the reflective layer is spatially positioned further from the outer surface of the outer pane than the masking layer and the electrically switchable functional membrane.

[0058] The imaging unit of the projection system emits light, which is positioned near the inner surface of the inner pane so that the imaging unit illuminates the inner surface of the inner pane, and the light is reflected by the reflective layer of the laminated pane. 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 incident on the reflective layer in the wavelength range of 400 nm to 700 nm and at an illumination angle of 55° to 80°. This is advantageous for achieving the highest possible brightness of the image emitted by the imaging unit and reflected by the reflective layer.

[0059] Because the imaging unit serves to project an image, it is sometimes referred to as a projector, display device, or image display device. Examples of imaging units that can be used include display devices known to those skilled in the art. The imaging unit is preferably a display, particularly preferably an LCD display, LED display, OLED display, or electroluminescent display, especially an LCD display. The low installation height of the display allows for easy and space-saving integration into the dashboard of a vehicle. Furthermore, the display can operate with significantly less energy than other imaging units. In the inventive combination of the reflective layer, the masking layer present at its base, and the electrically switchable functional film, the brightness of the display is relatively low but sufficient. The radiation of the imaging unit preferably strikes the laminate pane at an angle of incidence of 55° to 80°, preferably 62° to 77°, in the region of the reflective layer. The angle of incidence is the angle between the incident vector of the radiation of the image display device and the surface normal at the geometric center of the reflective layer.

[0060] The imaging unit is advantageously designed so that the entire area consisting of the masking layer and the electrically switchable functional film, or only the area of ​​the masking layer alone (when viewed vertically through the laminated pane), is freely used for reflection by the reflective layer. In other words, the imaging unit can generate an image such that the image is reflected by the reflective layer in the area that overlaps the combination of the masking layer and the electrically switchable functional film (when viewed vertically through the laminated pane). The image is therefore also reflected by the area of ​​the reflective layer that overlaps the electrically switchable functional film (when viewed vertically through the laminated pane). In this case, the electrically switchable functional film is in a first switching state (opaque). On the other hand, the imaging unit can generate an image such that the image is reflected by the reflective layer in the area that overlaps only the masking layer (when viewed vertically through the laminated pane) and therefore not the electrically switchable functional film. In this case, the electrically switchable functional film can be in a second switching state (transparent).

[0061] The laminated pane designs according to the invention described above equally apply to the projection installation according to the invention, and vice versa.

[0062] The present invention further provides a method for producing a laminated pane according to the present invention, comprising the steps of: a) providing an outer pane having an outer surface (I) and an inner surface (II), a thermoplastic intermediate layer, and an inner pane having an outer surface (III) and an inner surface (IV); b) Steps i)~iii): i) forming at least one masking layer disposed between an outer pane and an inner pane; ii) disposing at least one electrically switchable functional film switchable between a first switching state having a relatively low light transmittance and a second switching state having a relatively high light transmittance by application of an operating voltage, the electrically switchable functional film being disposed immediately adjacent to the masking layer or overlapping an opening in the masking layer when viewed vertically through the laminated pane, the masking layer and the electrically switchable functional film being disposed within the area of ​​the laminated pane; and iii) forming at least one reflective layer for light reflection on the outer surface (III) and / or the inner surface (IV) of the inner pane, wherein the reflective layer is formed completely within the area of ​​the laminated pane where the masking layer and the electrically switchable functional film are located when viewed vertically through the laminated pane; c) joining the outer and inner panes with a thermoplastic intermediate layer, wherein the thermoplastic intermediate layer is disposed between the outer and inner panes. A method of manufacturing is provided, comprising:

[0063] The steps can be performed in the order given, simultaneously, or in a different order. Step c) is performed after steps a) and b).

[0064] If the laminate pane is curved, a curved outer pane and a curved inner pane are introduced in step a). The laminate is produced in step c) by lamination methods well known to those skilled in the art. If a reflective layer is produced in step b), it can be applied by commonly known coating methods such as magnetron sputtering or cold gas spraying.

[0065] The embodiments of the laminated pane according to the invention described above equally apply to the method for manufacturing the laminated pane according to the invention.

[0066] The invention also relates to the use of a laminated pane according to the invention as a vehicle pane in a means of transport for land, air or water transport, in particular in a motor vehicle, in particular as a windscreen for a head-up display.

[0067] The various embodiments of the present invention can be implemented individually or in any combination, and in particular the features mentioned above and below can be used not only in a specific combination but also in other combinations or alone without departing from the technical scope of the present invention.

[0068] The invention will now be described in more detail with respect to exemplary embodiments and with reference to the accompanying drawings, which are schematic and not to scale, in which: [Brief explanation of the drawings]

[0069] [Figure 1] FIG. 1 is a plan view of one embodiment of a laminated pane according to the present invention. [Figure 2] FIG. 2 is a plan view of a further embodiment of a laminated pane according to the invention. [Figure 3] FIG. 3 is a cross-sectional view of the embodiment shown in FIG. [Figure 4] FIG. 4 shows a cross-sectional view of one embodiment of a projection installation according to the invention. [Figure 5A]FIG. 5A is a cross-sectional view of the embodiment shown in FIG. 1, in which the electrically switchable functional film is in a transparent switched state. [Figure 5B] FIG. 5B is a cross-sectional view of the embodiment shown in FIG. 1, in which the electrically switchable functional film is in an opaque switched state. [Figure 6A] FIG. 6A is a cross-sectional view of the embodiment shown in FIG. 2, in which the electrically switchable functional film is in a transparent switched state. [Figure 6B] FIG. 6B is a cross-sectional view of the embodiment shown in FIG. 2, in which the electrically switchable functional film is in an opaque switched state. [Figure 7A] FIG. 7A is a cross-sectional view of a further embodiment in which the electrically switchable functional film is in a transparent switched state. [Figure 7B] FIG. 7B is a cross-sectional view of a further embodiment in which the electrically switchable functional film is in an opaque switched state. [Figure 8A] FIG. 8A is a plan view of the embodiment of the laminated pane according to the invention of FIG. 2, in which the electrically switchable functional membrane is in the transparent switched state. [Figure 8B] FIG. 8B is a plan view of the embodiment of the laminated pane according to the invention of FIG. 2, in which the electrically switchable functional membrane is in the opaque switched state. [Figure 9] FIG. 9 illustrates by means of a flow chart an exemplary embodiment of the method according to the invention.

[0070] 1 and 2 each show a plan view of one embodiment of a laminated pane 100 according to the present invention, and FIG. 3 shows a cross section of the laminated pane 100 shown in FIG. 1 taken along section line XX'.

[0071] The laminated pane 100 shown in FIGS. 1 and 2 has an upper edge O, a lower edge U, and two side edges S. The laminated pane 100 further comprises an outer pane 1 having an outer surface I and an inner surface II, an inner pane 2 having an outer surface III and an inner surface IV, a thermoplastic intermediate layer 3, a first masking layer 4, and a second masking layer 8. The thermoplastic intermediate layer 3 is disposed between the outer pane 1 and the inner pane 2. The outer pane 1, the thermoplastic intermediate layer 3, and the inner pane 2 are disposed one on top of the other over their entire surfaces. The first masking layer 4 is disposed between the thermoplastic intermediate layer 3 and the inner pane 2 in a region of the laminated pane 100 whose surface coverage is less than that of the laminated pane 100; i.e., the first masking layer 4 does not extend over the entire surface of the laminated pane 100. The second masking layer 8 is arranged between the thermoplastic intermediate layer 3 and the outer pane 1 in an area of ​​the laminate pane 100 whose surface coverage is smaller than that of the laminate pane 100, i.e., the second masking layer 8 does not extend over the entire surface of the laminate pane 100. In the embodiment shown in Figures 1 and 2, the two masking layers 4, 8 are each formed as an opaque masking print and are arranged only in the edge area of ​​the laminate pane 100 adjacent to the lower edge U. In the embodiment shown in Figures 1 and 2, the two masking layers 4, 8 extend between the two side edges S of the laminate pane 100 and have a width of, for example, 30 cm starting from the lower edge U of the laminate pane 100.

[0072] The laminated pane 100 further comprises an electrically switchable functional membrane 6 that can be switched between a first switching state (opaque) having a relatively low light transmittance and a second switching state (transparent) having a relatively high light transmittance upon application of an operating voltage. In FIG. 1 , the electrically switchable functional membrane 6 is arranged to (completely) overlap the opening 7 of the first masking layer 4 when viewed vertically through the laminated pane 100. The opening 7 of the first masking layer 4 can be made opaque by the electrically switchable functional membrane 6 in the first switching state. In FIG. 2 , the electrically switchable functional membrane 6 is arranged to be immediately adjacent to the first masking layer 4 when viewed vertically through the laminated pane 100 in order to enlarge (without a gap) the opaque region of the laminated pane 100. In FIG. 2 , the first masking layer 4 does not have an opening. In other words, by using the first masking layer 4 in combination with the electrically switchable functional membrane 6, the size of the opaque areas of the laminated pane 100 can be freely changed as desired. When the electrically switchable functional membrane 6 is in a first switching state, the opaque areas of the laminated pane 100 are created by a combination of the first masking layer 4 and the opaque areas of the electrically switchable functional membrane 6 when viewed vertically through the laminated pane 100. When in a second switching state, the opaque areas of the laminated pane 100 are formed solely by the first masking layer 4. In Figures 1 and 2, the electrically switchable functional membrane 6 is in a transparent switching state in both cases.

[0073] The electrically switchable functional film 6 is a guest-host functional film, an electrochromic functional film, an SPD functional film, or a PDLC functional film. Typical values ​​of optical transparency (TL) and typical haze values ​​of the electrically switchable functional film are shown in the table below.

[0074] [Table 1]

[0075] Furthermore, the laminated pane 100 has a reflective layer 5 for light reflection on the outer surface (III) of the inner pane 2, wherein the reflective layer 5 is positioned entirely within the area of ​​the laminated pane 100 in which the first masking layer 4 and the electrically switchable functional membrane 6 are located when viewed vertically through the laminated pane 100.

[0076] Figure 3 shows a modification of the embodiment of Figure 1, in which the two masking layers 4, 8 are each designed to extend in a frame-like manner along their periphery, wherein the width of the area of ​​the masking layers 4, 8 arranged to overlap the reflective layer 5 (when viewed vertically through the laminated pane 100) is wider than the remaining parts of the masking layers 4, 8. For convenience, the frame-like periphery of the masking layer 4 is not shown in Figures 1 and 2.

[0077] The thermoplastic intermediate layer 3 may contain, for example, PVB and may be 0.76 mm thick. The outer pane 1 may be made of, for example, soda-lime glass and may be 2.1 mm thick. The inner pane 2 may be made of, for example, soda-lime glass and may be 1.6 mm thick.

[0078] It should be understood that the laminated pane 100 can have any suitable geometry and / or curvature. Typically, the laminated pane 100 is a curved laminated pane. The laminated pane 100 is, for example, an automobile windshield.

[0079] FIG. 4 shows a cross-sectional view of one embodiment of a projection installation 101 according to the present invention. The projection installation 101 shown in FIG. 4 comprises a laminated pane 100 and an imaging unit 9. The imaging unit 9 generates p-polarized and / or s-polarized light (image information). This p-polarized and / or s-polarized light (image information) is directed toward a reflective layer 5, where it is reflected by the reflective layer 5 into the interior of the vehicle, where it can be perceived by an observer, e.g., a driver. The reflective layer 5 is suitably designed to reflect the light of the imaging unit 9. The light is incident on the reflective layer 5 at an incident angle of preferably 55° to 80°, particularly 62° to 77°. The imaging unit 9 is, for example, a display, particularly an LCD display. Preferably, the imaging unit 9 functions to generate only p-polarized light. P-polarized light can be easily viewed, particularly with polarized sunglasses equipped with an s-polarizing filter.

[0080] The imaging unit 9 is designed so that an image is directed onto the reflective surface 5, and this design is such that either the area of ​​the reflective layer 5 that overlaps with the first masking layer 4 and the area of ​​the electrically switchable functional film 6 (when viewed vertically through the laminated pane 100), or the area of ​​the reflective layer 5 that overlaps with only the first masking layer 4, is freely used for reflection.

[0081] 5A shows a cross-sectional view of the embodiment shown in FIG. 1, in which the electrically switchable functional membrane 6 is in a transparent switched state (with no operating voltage applied). In this case, the opaque area of ​​the laminated pane 100 is reduced to the first masking layer 4, i.e., the opening 7 is transparent. The image produced by the imaging unit 9 is produced such that the image is reflected by the reflective layer 5 in areas that overlap only the first masking layer 4 (when viewed vertically through the laminated pane), and therefore not the electrically switchable functional membrane 6.

[0082] 5B shows a cross-sectional view of the embodiment shown in FIG. 1, in which the electrically switchable functional membrane 6 is in an opaque switched state (a state in which an operating voltage is applied). In this case, the opaque region of the laminated pane 100 is caused by the combination of the electrically switchable functional membrane 6 and the first masking layer 4, i.e., the entire opening 7 is opaque. The image produced by the imaging unit 9 is produced such that (when viewed perpendicularly through the laminated pane 100) the image is reflected by the reflective layer 5 in the area that overlaps the combination of the first masking layer 4 and the electrically switchable functional membrane 6.

[0083] In the embodiment of FIG. 1, the two masking layers 4, 8 each have an opening, and the portions of the masking layers 4, 8 that are closer to the upper edge O can be used to position the electrical connections of the electrically switchable functional membrane 6 in a concealed manner.

[0084] Figures 7A and 7B show further embodiments of a laminated pane 100 according to the invention. The embodiment shown in cross section in Figure 7A (similar to Figure 6A) differs from that shown in Figure 6A only in that the reflective layer 5 is arranged on the inner surface (face IV) of the inner pane 2 rather than on the outer surface (face III) of the inner pane 2. The embodiment shown in cross section in Figure 7B (similar to Figure 6B) differs from that shown in Figure 6B only in that the reflective layer 5 is arranged on the inner surface (face IV) of the inner pane 2 rather than on the outer surface (face III) of the inner pane 2. In Figures 7A and 7B, the electrically switchable functional membrane 6 is again shown in a transparent switched state (Figure 7A) and an opaque switched state (Figure 7B).

[0085] Figures 8A and 8B show the change in size of the opaque area of ​​the laminated pane 100 relative to the plan view of the embodiment of the laminated pane according to the invention in Figure 2. The electrically switchable functional membrane 6 is in a transparent switched state in Figure 8A and in an opaque switched state in Figure 8B. The size of the opaque area of ​​the laminated pane 100 can be easily changed by switching the electrically switchable functional membrane 6.

[0086] FIG. 9 illustrates an exemplary embodiment of the method according to the present invention in a flow chart.

[0087] In step S1, an outer pane 1 with an outer surface I and an inner surface II, a thermoplastic intermediate layer 3 and an inner pane 2 with an outer surface III and an inner surface IV are provided.

[0088] In the process S2 including multiple sub-processes, - forming at least one masking layer 4 arranged between the outer and inner panes, - arranging at least one electrically switchable functional film 6 which can be switched between a first switching state having a relatively low light transmittance and a second switching state having a relatively high light transmittance by application of an operating voltage, such that when viewed vertically through the laminated pane 100, the at least one electrically switchable functional film 6 is immediately adjacent to the masking layer 4 or overlaps an opening 7 in the masking layer 4, wherein the masking layer 4 and the electrically switchable functional film 6 are arranged in the area of ​​the laminated pane 100; - forming at least one reflective layer 5 for light reflection on the outer surface (III) and / or the inner surface (IV) of the inner pane 2, wherein the reflective layer 5 is formed entirely within the area of ​​the laminated pane 100 in which the masking layer 4 and the electrically switchable functional film 6 are arranged when viewed vertically through the laminated pane 100;

[0089] In step S3, the outer pane 1 and the inner pane 2 are joined by a thermoplastic intermediate layer 3, where the thermoplastic intermediate layer 3 is disposed between the outer pane 1 and the inner pane 2.

[0090] Steps S1, S2, and S3 can be performed in any order or simultaneously, with step S3 occurring after steps S1 and S2.

[0091] The present invention provides an improved laminated pane, in which the size of the opaque area of ​​the laminated pane can be freely changed by switching at least one electrically switchable functional film. In this way, the image of the projector can be reflected by differently sized areas of the reflective layer, resulting in a good visual perception of the virtual image with sufficient brightness and high contrast, thereby ensuring good visibility of safety-related information in all weather and lighting conditions. In particular, if a maximum see-through area through the laminated pane is desired, the opaque area of ​​the laminated pane can be freely reduced to the opaque area of ​​the masking layer. Furthermore, undesirable secondary images can be avoided. The laminated pane can be produced efficiently and cost-effectively in continuous industrial production, whereby the production of the laminated pane can be easily implemented using standard manufacturing processes. [Explanation of symbols]

[0092] 100 stacked panes 101 Projection equipment 1 outer pane 2 inner panes 3 Thermoplastic Interlayer 4 First Masking Layer 5 Reflective layer 6 Functional membranes 7 Openings 8 Second Masking Layer 9 Imaging Unit O The top edge of the laminated pane 100 U Lower edge of laminated pane 100 S Side edge of laminated pane 100 I. Outer surface of outer pane 1 II. Inner surface of outer pane 1 III. Outer surface of inner pane 2 IV Inner surface of inner pane 2

Claims

1. A laminated pane (100), comprising: an outer pane (1) with an outer surface (I) and an inner surface (II); a thermoplastic intermediate layer (3), an inner pane (2) with an outer surface (III) and an inner surface (IV); at least one masking layer (4) placed between said outer pane (1) and said inner pane (2); at least one electrically switchable functional membrane (6) that can be switched between a first switching state with a relatively low light transmittance and a second switching state with a relatively high light transmittance by application of an operating voltage, said electrically switchable functional membrane (6) being arranged so as to be immediately adjacent to said masking layer (4) or so as to overlap an opening (7) of said masking layer (4) when viewed vertically through said laminated pane (100), said masking layer (4) and said electrically switchable functional membrane (6) being arranged in the area of ​​said laminated pane (100); - at least one reflective layer (5) for light reflection present on the outer surface (III) and / or the inner surface (IV) of the inner pane (2), which reflective layer (5) is arranged entirely in the area of ​​the laminated pane (100) where the masking layer (4) and the electrically switchable functional membrane (6) are arranged, when viewed perpendicularly through the laminated pane (100); A laminated pane (100) comprising:

2. 2. The laminated pane (100) of claim 1, wherein the electrically switchable functional membrane (6) has a light transmittance of less than 1.5% in the first switching state and a light transmittance of more than 30% in the second switching state.

3. 3. The laminated pane (100) according to claim 1 or 2, wherein the electrically switchable functional film (6) is selected from a guest-host functional film, an electrochromic functional film, an SPD functional film, and a PDLC functional film.

4. 4. Laminated pane (100) according to any one of claims 1 to 3, wherein the reflective layer (5) reflects at least 10%, preferably at least 50%, particularly preferably at least 80%, in particular at least 90% of visible light.

5. Laminated pane (100) according to any one of claims 1 to 4, wherein the reflective layer (5) is a metal layer.

6. 6. Laminated pane (100) according to claim 5, wherein the reflective layer (5) comprises or consists of aluminium, titanium and / or nickel, in particular aluminium.

7. 7. A laminated pane (100) according to any one of claims 1 to 6, wherein the masking layer (4) is designed to extend in the shape of a frame along the periphery, and has a width greater in the part where it overlaps with the reflective layer (5) than in the remaining part.

8. 8. A laminated pane (100) according to any one of claims 1 to 7, wherein the masking layer (4) is formed as an opaque masking print arranged on the inner surface (II) of the outer pane (1) and / or the outer surface (III) of the inner pane (2).

9. A laminated pane (100) according to any one of the preceding claims, wherein the masking layer (4) is formed as an opaque coloured area of ​​the thermoplastic interlayer (3).

10. The laminated pane (100) of any one of claims 1 to 9, wherein the laminated pane (100) is a curved laminated pane.

11. A projection facility (101), comprising: a laminated pane (100) according to any one of claims 1 to 10, an imaging unit (9) directed towards said reflective layer (5); A projection facility (101) comprising:

12. A method for manufacturing a laminated pane (100) according to any one of claims 1 to 10, comprising the steps of: a) providing an outer pane (1) with an outer surface (I) and an inner surface (II), a thermoplastic intermediate layer (3), and an inner pane (2) with an outer surface (III) and an inner surface (IV); b) forming at least one masking layer (4) arranged between the outer pane (1) and the inner pane (2); and arranging at least one electrically switchable functional membrane (6) switchable between a first switching state having a relatively low light transmittance and a second switching state having a relatively high light transmittance by application of an operating voltage, said arrangement being carried out so that, when viewed vertically through the laminated pane (100), said electrically switchable functional membrane (6) is immediately adjacent to said masking layer (4) or overlaps with an opening (7) in said masking layer (4). wherein the masking layer (4) and the electrically switchable functional membrane (6) are arranged within the area of ​​the laminated pane (100), and a step of forming at least one reflective layer (5) for light reflection on the outer surface (III) and / or the inner surface (IV) of the inner pane (2), wherein the reflective layer (5) is formed completely within the area of ​​the laminated pane (100) where the masking layer (4) and the electrically switchable functional membrane (6) are arranged, when viewed vertically through the laminated pane (100), c) joining said outer pane (1) and said inner pane (2) by said thermoplastic intermediate layer (3), wherein said thermoplastic intermediate layer (3) is disposed between said outer pane (1) and said inner pane (2); A manufacturing method comprising:

13. Use of a laminated pane (100) according to any one of claims 1 to 10 in means of transport for land, air or water transport, in particular as a vehicle pane in a motor vehicle, in particular as a windscreen for a head-up display.

Images