Composite disc with wedge-shaped intermediate layer

Abstract

Composite screen (1) for a projection arrangement (100) with a HUD area (H) for separating an interior space (15) from an external environment (16), comprising an outer screen (2) and an inner screen (3) which are firmly connected to each other by an intermediate layer (4), wherein the intermediate layer (4) is wedge-shaped at least in the HUD area of ​​the composite screen, wherein the intermediate layer (4) contains at least one plastic layer (9) made of a thermoplastic material and at least one adhesive layer (8) made of a cured adhesive,wherein the at least one adhesive layer (8) is wedge-shaped at least in the HUD area (H) and wherein the plastic layer (9) made of a thermoplastic material does not have a wedge shape and wherein a reflective layer (11) for reflecting light from a projector (12) is arranged on an outer surface of the inner disc (3) or on an inner surface of the inner disc (3) or the at least one adhesive layer (8) made of a cured adhesive has at least one reflective section (6) with at least one optically active additive for reflecting light from a projector (13).

Description

[0001] The present invention lies in the technical field of disk manufacturing and relates to a composite disk for a projection arrangement with a wedge-shaped intermediate layer, and a projection arrangement with the composite disk.

[0002] Modern cars are increasingly equipped with head-up displays (HUDs). A projector, typically located in the dashboard, projects images onto the HUD area of ​​the windshield, where they are reflected and perceived by the driver as a virtual image (from their perspective) behind the windshield. This allows important information previously displayed on the dashboard, such as time, speed, engine RPM, navigation system information, or even a rear-view camera image, to be projected into the driver's field of vision, replacing traditional side or rearview mirrors. The driver can perceive this information without taking their eyes off the road. Head-up displays can thus significantly contribute to improved road safety.

[0003] The problem with the head-up displays described above is that the image projected by the projector is reflected off both outer surfaces of the windshield. As a result, the driver not only perceives the desired main image, caused by the reflection off the inner surface of the windshield (primary reflection), but also a slightly offset, usually less intense secondary image, caused by the reflection off the outer surface of the windshield (secondary reflection). The latter is commonly referred to as a ghost image. This problem is solved by positioning the reflective surfaces at a deliberately chosen angle to each other, so that the main image and the secondary / ghost image are superimposed, thus making the ghost image less noticeable.

[0004] Windshields generally consist of two individual panes, typically made of glass, which are firmly bonded (laminated) together by at least one thermoplastic interlayer. If the surfaces of the glass panes are to be arranged at an angle to each other, as described, it is common to use a thermoplastic film with a non-constant thickness. This is also referred to as a wedge-shaped film or wedge foil.

[0005] The angle between the two surfaces of the film is called the wedge angle. The wedge angle can be constant across the entire film (linear thickness change) or change depending on the position (nonlinear thickness change). Laminated glass with wedge films is known, for example, from WO 2009 / 071135 A1, EP 1800855 B1, or EP 1880243 A2.

[0006] A disadvantage is the relatively high cost of manufacturing wedge-shaped films. Furthermore, wedge-shaped films are not equally suitable for all laminated windshields; they must be adapted to the specific type of windshield and its installation situation. This can sometimes be problematic or even impossible with very shallow-profile windshields.

[0007] Besides the transparent viewing area, windshields typically have a masking area with an opaque masking layer through which no visibility is possible. This masking area is usually located around the perimeter of the windshield and surrounds the transparent viewing area. Its primary purpose is to protect the adhesive used to bond the windshield to the vehicle body from UV radiation. The masking area is typically created by a black masking print on the surface of the outer pane facing the intermediate layer. In industrial mass production, the common practice is to apply ceramic inks using screen printing to create this masking print.

[0008] It is also possible to generate a virtual image in the masking area, whereby the masking area is illuminated with the image from a projector and the light is reflected there, thus creating a virtual image for the driver, for example in the section of the masking area that borders the lower edge of the windshield. A projection arrangement of this type is known, for example, from DE 102009020824 A1. The reflection of light in the masking area places different demands on the construction of a laminated windshield than that of HUD reflection. Typically, the outer or inner surface of the inner windshield is provided with a special reflective layer for this purpose, for example by sputtering.The deposition of layers by sputtering is a common procedure in the industrial mass production of windshields and is technically mastered, but this requires a considerable effort and additional costs.

[0009] WO 2022 / 131097 A1 discloses a projection arrangement for a HUD of a laminated pane of a moving object. WO 2018 / 208347 A1 discloses the composition of a laminating adhesive which can be used, for example, in laminated glass panes. WO 2018 / 208348 A1 discloses a method for laminating two substrates, for example, glass, using silicone-based adhesive compositions.

[0010] In contrast, the object of the present invention is to avoid the aforementioned disadvantages and to provide an improved windshield that can be manufactured in industrial series production in a time- and cost-efficient manner and with high quality. In particular, this should be possible in a simple way using existing production facilities.

[0011] These and other problems are solved according to the invention by a composite disk as defined in the independent claim. Advantageous embodiments of the invention are described in the dependent claims.

[0012] According to the invention, a laminated glass pane, preferably laminated glass, is shown for a projection arrangement with a HUD (Head-Up Display) area. The HUD area of ​​the laminated glass is a region of the laminated glass designed to be illuminated by a projector in a projection arrangement, so that a head-up display image can be shown in the HUD area. The HUD area is therefore located in a region of the laminated glass that is at least partially transparent with a light transmittance (according to ISO 9050:2003) of preferably at least 50%, particularly preferably at least 70%. If the laminated glass is, for example, a windshield in a car, the HUD area is a region through which a viewer (e.g., the driver) can see the road.

[0013] The composite disc has a circumferential edge, which preferably includes a top edge and a bottom edge, as well as two intermediate side edges, one left and one right. The top edge is the edge intended to point upwards in the installed position. The bottom edge is the edge intended to point downwards in the installed position. The top edge is often also referred to as the roof edge and the bottom edge as the motor edge. The composite disc can have any suitable geometric shape and / or curvature.

[0014] The composite pane comprises an outer pane and an inner pane, which are firmly bonded together by an intermediate layer. The intermediate layer preferably extends over the entire surface of the composite pane, i.e., it is arranged across the area between the outer pane and the inner pane.

[0015] The laminated glass pane is designed to separate the interior from the exterior environment within an opening in a surrounding structure, such as a vehicle window. The outer pane is positioned closer to the exterior than the inner pane. Both panes have an outer and an interior surface, with a circumferential edge running between them. The outer surface is the primary surface intended to face the exterior when installed. The interior surface is the primary surface intended to face the interior when installed. The interior surface of the outer pane and the outer surface of the inner pane face each other and are connected by the interlayer.Common terms also include "Side I" for the outer surface of the outer pane, "Side II" for the inner surface of the outer pane, "Side III" for the outer surface of the inner pane, and "Side IV" for the inner surface of the inner pane.

[0016] The intermediate layer is wedge-shaped, at least in the HUD area of ​​the composite lens. That is, the intermediate layer is wedge-shaped at least in the area where the intermediate layer and the HUD area overlap when viewed through the composite lens.

[0017] Crucially, the intermediate layer contains at least one adhesive layer made of a cured adhesive, with the adhesive layer being wedge-shaped at least in the HUD area. The intermediate layer thus has at least one wedge-shaped area made of a cured adhesive or one that can be cured during the manufacturing process of the composite disc.

[0018] According to a first aspect of the invention, the intermediate layer comprises at least one adhesive layer made of a cured adhesive and at least one plastic layer made of a thermoplastic material. Advantageously, the adhesive layer made of a cured adhesive is arranged between the plastic layer made of a thermoplastic material and one of the two discs. The adhesive layer made of a cured adhesive is wedge-shaped, at least in the HUD area. Advantageously, the entire adhesive layer made of a cured adhesive is wedge-shaped. Advantageously, the adhesive layer is provided in film form, particularly as a wedge-shaped film, and cured in the composite disc. The plastic layer made of a thermoplastic material does not have a wedge shape. Advantageously, the plastic layer made of a thermoplastic material is provided in film form, i.e., as a non-wedge-shaped film.

[0019] According to a second aspect of the invention, the composite disc comprises a reflective layer applied to the outer surface of the inner disc (side III) or to the inner surface of the inner disc (side IV). The reflective layer is designed to reflect light radiation and serves to generate the virtual main image by reflecting the light radiation (image) from a projector.

[0020] The following statements refer equally to the first aspect and the second aspect of the invention, unless otherwise stated.

[0021] Regarding the reflection of light radiation in the HUD area of ​​the composite screen, various configurations are possible in which unwanted, disruptive secondary images (ghost images) can occur. It is assumed in each case that light radiation (image) from a projector located on the inside of the inner screen is directed onto the composite screen and reflected by the composite screen in the HUD area (virtual image). For ease of distinction, the image reflected by primary reflection at the composite screen is referred to as the "main image," while the image reflected by unwanted secondary reflection is referred to as the "secondary image" or "ghost image." The main image is intended to be perceived by the viewer as a virtual representation of the projected image.

[0022] In an embodiment according to the first aspect of the invention, a primary reflection of the light radiation emitted by the projector occurs on the inner surface of the inner disc (side IV), thereby creating the virtual main image, while a secondary reflection on the outer surface of the outer disc (side I) generates a virtual secondary image. The wedge-shaped intermediate layer, at least in the HUD area, is intended to superimpose or at least approximate the main and secondary images in order to avoid or at least reduce disturbing optical effects.

[0023] In one embodiment according to the first aspect of the invention and in one embodiment according to the second aspect of the invention, a reflective layer is applied to the outer surface of the inner disk (side III), which is designed to reflect light radiation from the projector (image). The reflection of light radiation at the reflective layer creates the virtual main image. Secondary reflections of the incident light radiation at the outer surface of the outer disk (side I) and at the inner surface of the inner disk (side IV) create virtual secondary images. The wedge-shaped intermediate layer, at least in the HUD area, is intended to superimpose or at least approximate the main image and the secondary image generated by reflection at side I, whereas the secondary image generated by reflection at side IV can be prevented by an anti-reflective layer applied to side IV.

[0024] In one embodiment according to the first aspect of the invention and in one embodiment according to the second aspect of the invention, a reflective layer is applied to the inner surface of the inner disk (side IV), which is designed to reflect light radiation from the projector (image). The primary reflection of light radiation at the reflective layer creates the virtual main image. A secondary reflection of the incident light radiation at the outer surface of the outer disk (side I) generates a virtual secondary image. The wedge-shaped intermediate layer, at least in the HUD area, is intended to superimpose or at least approximate the main image and the secondary image generated by reflection at side I.

[0025] The wedge-shaped intermediate layer, at least in some areas, allows the composite disc to be designed in such a way that when images are projected onto the HUD area, virtual main and secondary images can be brought at least close to each other and advantageously superimposed, in order to reduce or even completely avoid disturbing optical effects caused by ghost images.Thus, a virtual main image, which is generated according to the respective embodiment by primary reflection at the inner surface of the inner disk (side IV) according to the first aspect of the invention, or by primary reflection at a reflective layer applied to the inner surface of the inner disk (side IV) according to the first and second aspects of the invention, or by primary reflection at a reflective layer applied to the outer surface of the inner disk (side III) according to the first and second aspects of the invention, can be brought at least to an approximation of and preferably to a superposition with a virtual secondary image generated by reflection at the outer surface (side I) of the outer disk, in order to avoid disturbing optical effects.

[0026] In the context of the invention, "wedge-shaped or partially wedge-shaped intermediate layer" means that the intermediate layer, in a cross-sectional view, has a wedge shape in a region or entirely. The intermediate layer does not have a constant thickness in this region, but rather a variable thickness with a thicker first end and a thinner second end. The angle between the two surfaces in the wedge-shaped region of the intermediate layer is called the wedge angle. If the wedge angle is not constant, the tangents to the surfaces are used to measure it at a given point.

[0027] The intermediate layer is wedge-shaped or wedge-like, at least in the HUD area. The wedge angle can be constant along the vertical path, resulting in a linear change in the thickness of the intermediate layer, with the thickness typically increasing from bottom to top. The direction "from bottom to top" refers to the direction from the bottom edge to the top edge of the composite disk, i.e., the vertical path. However, more complex thickness profiles are also possible, in which the wedge angle varies from bottom to top (i.e., is location-dependent along the vertical path), either linearly or non-linearly.

[0028] In principle, it is possible to use a wedge-shaped outer pane to angle the reflective surfaces relative to each other. In other words, a wedge-shaped outer pane can be used in combination with an intermediate layer that is at least partially wedge-shaped. In this case, it is advantageous if the wedge angle can be fine-tuned via the intermediate layer or adhesive layer.

[0029] In the composite disc according to the invention, the wedge angle of the intermediate layer, which is at least partially wedge-shaped, is selected such that a virtual main image generated by primary reflection on the inner surface of the inner disc (side IV) according to the first aspect of the invention, or by primary reflection on a reflective layer applied to the inner surface of the inner disc (side IV) according to the first and second aspects of the invention, or by primary reflection on a reflective layer applied to the outer surface of the inner disc (side III) according to the first and second aspects of the invention, can be brought at least to an approximation or even to a superposition of a virtual secondary image generated by secondary reflection on the outer surface (side I) of the outer disc.In the case of parallel reflective surfaces, the primary image and the secondary image (ghost image) would appear offset from each other, which is distracting for the viewer. The wedge angle essentially superimposes the secondary image spatially with the primary image, so that the viewer perceives only a single image or at least reduces the distance between the primary and secondary images. Typical wedge angles range from 0.3 mrad to 0.7 mrad, and especially from 0.4 mrad to 0.5 mrad.

[0030] The intermediate layer is wedge-shaped, at least in the HUD area, so that visible light from a projector can be reflected without or largely without ghosting. According to the invention, the adhesive layer, made of a cured adhesive, is wedge-shaped, at least in the HUD area, so that the adhesive layer, which is wedge-shaped at least in some areas, contributes to the wedge shape of the intermediate layer.

[0031] According to the first aspect of the invention, and in a particularly advantageous embodiment according to the second aspect of the invention, the wedge shape of the intermediate layer, present at least in the HUD area, is formed exclusively by the wedge shape of the adhesive layer made of a cured adhesive. This is a major advantage of the invention, since the adhesive layer made of a cured adhesive, which is wedge-shaped at least in the HUD area, can be produced more cost-effectively than a wedge-shaped thermoplastic film. Furthermore, the wedge shape of the adhesive layer made of a cured adhesive offers a high degree of variability, so that windshields according to the invention can be manufactured in many different sizes and shapes and, in particular, can also be installed in very shallow mounting positions, which is another major advantage of the invention.

[0032] According to the invention, the intermediate layer of the composite disc contains an adhesive layer made of a cured adhesive which, without an optically active additive (see details below), is typically optically transparent. For the purposes of the invention, the cured or curable adhesive is a substance suitable for material bonding that can be irreversibly transformed from a curable (initial) state to a cured (final) state. Typically, this is a plastic that is brought into a polymer-crosslinked state by curing. This distinguishes the cured adhesive significantly from a thermoplastic polymer, which, although it can also be optically transparent and serve as an adhesive, can be reversibly softened by the application of heat. In contrast, the cured adhesive cannot be returned to a flowable state.It cannot be softened once it has cured. The cured adhesive is therefore not a thermoplastic and is fundamentally different from one. In other words, a thermoplastic and a curable or cured adhesive are different from each other. For the purposes of the present invention, the term "adhesive layer" refers to a layer of a curable or cured plastic, whereas the term "plastic layer" refers to a layer of a (non-curable) thermoplastic.

[0033] In one embodiment, the curable adhesive can be cured by heat, exposure to electromagnetic radiation, preferably UV radiation, and / or chemically. Preferably, curing is achieved by the application of heat or an increase in temperature and / or UV radiation.

[0034] Curable adhesives are well known in the art. In the composite disc according to the invention, adhesives that are optically transparent (without an optically effective additive, which would also make the adhesive opaque) are advantageously used. These are typically sold commercially under the abbreviations LOCA ("Liquid Optically Clear Adhesive") and OCA ("Optical Clear Adhesive") in flowable form or in tape or film form. They are also frequently used in touch-sensitive displays, for example, to firmly bond them to an LCD display or to firmly bond plastic covers to the touch-sensitive displays. After application, the LOCA or OCA in film form is often cured by UV radiation. Optically transparent adhesives are readily available from a large number of suppliers.

[0035] In one embodiment, the curable or cured adhesive contains or consists of polyurethane (PU), polyacrylate, polyacetate resin, casting resin, silicone, or a copolymer or mixture thereof. Advantageously, the curable or cured adhesive consists of a casting resin, particularly one based on polyurethane, polyacrylate, or silicone. Advantageously, the curable or cured adhesive is based on polyacrylate or polyurethane. These are common and proven materials for such adhesives, which are commercially available, including in film form.

[0036] According to the first aspect of the invention and in an embodiment according to the second aspect of the invention, the intermediate layer is formed at least partially wedge-shaped solely by the adhesive layer made of a cured adhesive (i.e., not additionally by an at least partially wedge-shaped plastic layer made of a thermoplastic material), which is more cost-effective compared to a wedge-shaped plastic layer made of a thermoplastic material and allows for greater variability of the composite disc and its installation situations. In an embodiment according to the second aspect of the invention, the intermediate layer does not contain a plastic layer made of a thermoplastic material, and in particular, the intermediate layer can consist only of the adhesive layer made of a cured adhesive.

[0037] In an embodiment according to the second aspect of the invention, the intermediate layer comprises at least one adhesive layer made of a cured adhesive and at least one plastic layer made of a thermoplastic material. Advantageously, the adhesive layer made of a cured adhesive is arranged between the plastic layer made of a thermoplastic material and one of the two discs. The adhesive layer made of a cured adhesive is wedge-shaped, at least in the HUD area. Advantageously, the entire adhesive layer made of a cured adhesive is wedge-shaped. Advantageously, the adhesive layer is provided in film form, particularly as a wedge-shaped film, and cured in the composite disc. In this case, the plastic layer made of a thermoplastic material does not have a wedge shape. Advantageously, the plastic layer made of a thermoplastic material is provided in film form, i.e.,as a non-wedge-shaped film.

[0038] In one embodiment according to the first aspect of the invention and in another embodiment according to the second aspect of the invention, the adhesive layer, made of a cured adhesive, is advantageously equal in area to the plastic layer made of a thermoplastic material. The plastic layer made of thermoplastic material is typically at least approximately equal in area to the composite pane, whereby – as is known in the trade – an edge region may be omitted, wherein, in a perpendicular view, at least 90% of the composite pane is covered by the plastic layer made of a thermoplastic material. Advantageously, the adhesive layer made of a cured adhesive serves to firmly bond the two panes to form the composite pane.

[0039] In an embodiment according to the first aspect of the invention and in an embodiment according to the second aspect of the invention, the adhesive layer made of a cured adhesive surrounds the plastic layer made of a thermoplastic material at least partially, in particular completely, wherein the adhesive layer made of a cured adhesive is arranged in an edge region of the composite disc which includes at least the HUD region of the composite disc.

[0040] In an embodiment according to the second aspect of the invention, the outer pane and the inner pane are firmly connected to each other only by the at least one adhesive layer made of a curable adhesive, wherein the intermediate layer advantageously consists only of the adhesive layer made of the cured adhesive. Thus, the two panes of the composite pane are firmly connected to each other only by the adhesive layer made of a cured adhesive, wherein the area of ​​the adhesive layer made of a cured adhesive corresponds at least approximately to the area of ​​the composite pane, and wherein, in a perpendicular view, at least 90% of the composite pane is covered by the adhesive layer made of a cured adhesive.

[0041] In one embodiment according to the first aspect of the invention and according to the second aspect of the invention, the composite disc comprises a reflective layer applied to the outer surface of the inner disc (side III) or to the inner surface of the inner disc (side IV). The reflective layer is designed to reflect light radiation and serves to generate the virtual main image by reflecting the light radiation (image) from a projector. Such reflective layers are known in the trade; see, for example, DE 102014220189 A1, US 2017242247 A1, WO 2019046157 A1, WO 2019179682 A1, and WO 2019179683 A1. The reflective layer is arranged at least in the HUD area of ​​the composite disc.

[0042] The reflective layer is, for example, transparent, which, in the context of the invention, means that it has an average transmission in the visible spectral range of at least 70%, preferably at least 80%, and thus does not significantly restrict the view through the composite pane. However, it is also possible for the reflective layer to be opaque.

[0043] Essentially, the reflective layer is not limited to a specific composition, and any reflective layer can be used as long as it is suitable for reflecting the light radiation (image) emitted by the projector. To generate a high-intensity virtual HUD image, the reflective layer should have a high reflectance, particularly in the spectral range of 450 nm to 650 nm, which is especially relevant for HUD displays. The composite disk with the reflective layer preferably has an average reflectance of at least 15%, and more preferably at least 20%, in the spectral range of 450 nm to 650 nm.

[0044] The reflective layer is typically a thin-film stack, i.e., a sequence of thin individual layers. In one embodiment, the reflective layer comprises at least one electrically conductive layer, which is primarily responsible for the reflective effect. The electrically conductive layer can be a metal-containing layer or a layer based on a transparent conductive oxide (TCO). The metal-containing layer can, for example, be based on silver, gold, aluminum, or copper. A common TCO is indium tin oxide (ITO). For example, the metal-containing layer contains at least 90 wt% silver, preferably at least 99 wt% silver. The reflective layer can also, in particular, contain a polymeric film.

[0045] The reflective layer on side III is particularly suitable for reflecting only p-polarized radiation. The reflective layer on side IV is particularly suitable for reflecting both s-polarized and p-polarized radiation. The polarization direction is specified in relation to the plane of incidence of the radiation on the composite disk. P-polarized radiation is defined as radiation whose electric field oscillates in the plane of incidence. S-polarized radiation is defined as radiation whose electric field oscillates perpendicular to the plane of incidence. The plane of incidence is defined by the incidence vector and the surface normal of the composite disk at the geometric center of the irradiated area.

[0046] The laminated glass can be covered with the reflective layer across its entire surface, which may be preferred for manufacturing reasons. In one embodiment, at least 50%, and in particular at least 80%, of the glass surface is covered with the reflective layer. Specifically, the reflective layer is applied to the entire surface of the glass, with the exception of a circumferential edge area and, optionally, a local area intended to ensure the transmission of electromagnetic radiation through the windshield as a communication, sensor, or camera window, and which is therefore not covered with the reflective layer. The circumferential uncoated edge area has, for example, a width of up to 20 cm. It prevents direct contact between the reflective layer and the surrounding atmosphere, thus protecting the reflective layer inside the laminated glass from corrosion and damage.

[0047] In one embodiment, if a reflective layer is arranged on the outer surface of the inner pane (side III), the composite pane comprises an anti-reflective layer applied to the inner surface of the inner pane (side IV). Such anti-reflective layers are known in the art; see, for example, WO 2019179682 A1, WO 2019179683 A1, WO 2019206493 A1, and US 20190064516 A1. In contrast to the reflective layer, the anti-reflective layer effectively suppresses the reflection of the light radiation emitted by the projector at the inner surface of the inner pane (side IV), so that the light radiation (image) is only significantly reflected as a virtual principal image by the reflective layer on the outer surface of the inner pane (side III), and an optically disturbing virtual secondary image is avoided by reflection at side IV.The anti-reflective layer preferably has a reflectance for the incident light radiation from the projector of less than 10%, particularly preferably less than 1%. The anti-reflective layer preferably extends over at least 50%, particularly at least 80%, of the surface of the composite disc, and particularly over the entire surface of the composite disc, with the above descriptions for the reflective layer applying analogously.

[0048] Preferably, the reflective layer and the antireflective layer are arranged overlapping in the view through the composite pane, wherein the reflective layer and the antireflective layer have, for example, the same area dimensions.

[0049] In principle, it is sufficient if the HUD area of ​​the composite lens is provided with the reflective layer and preferably also with the antireflective layer. In one embodiment, the reflective layer and preferably also the antireflective layer are arranged at least in the HUD area of ​​the composite lens. In another embodiment, the reflective layer and preferably the antireflective layer are arranged only in the HUD area of ​​the composite lens.

[0050] However, other areas of the composite disc can also be provided with the reflective layer and, optionally, the antireflective layer. In particular, the reflective layer and preferably also the antireflective layer can be arranged overlapping (in view through the composite disc) an opaque masking layer. In one embodiment, the reflective layer and preferably also the antireflective layer are arranged at least overlapping an opaque masking layer.

[0051] The masking layer can be an opaque enamel or an opaque thermoplastic film. It can also be a partially opaque thermoplastic film and thus a component of the intermediate layer. The masking layer is, in particular, a dark, preferably black, enamel applied to the outer pane. The masking layer is preferably applied to the interior surface of the outer pane (side II). The masking layer is preferably a peripheral (frame-shaped) layer extending along the perimeter edge of the laminated pane. The masking layer primarily serves as UV protection for the adhesive used to mount the laminated pane, for example, when bonding it into a vehicle. The masking layer preferably has a transmission coefficient (according to ISO 9050:2003) for visible light of less than 15%, more preferably less than 10%, and most preferably less than 1%.The masking layer can also be semi-transparent, at least in sections, for example as a dot matrix, stripe matrix, or grid. Alternatively, the masking layer can also have a gradient, for example from an opaque covering to a semi-transparent covering.

[0052] In one embodiment of the invention, the masking layer is arranged in a frame-like manner in the circumferential edge region of the composite disc and is widened in a section of the circumferential edge region adjacent to the lower edge of the composite disc. The masking layer preferably has a width of 10 cm or more, particularly preferably 20 cm or more, and especially 30 cm or more, in the widened area. This embodiment is particularly suitable for use in vehicles where the projection arrangement can be used as an alternative to displays installed in the dashboard. Alternatively, the masking layer can be applied in a lower edge region of the composite disc adjacent to the lower edge and / or in an upper edge region of the composite disc adjacent to the upper edge.

[0053] In one embodiment, the adhesive layer, consisting of a cured adhesive, contains at least one optically active additive in at least one section, which adjusts the reflection, transmission, tint, and / or absorption of light by the laminated glass. The optically active additive allows one or more optical properties of the cured adhesive to be adjusted or modified compared to the cured adhesive without the additive.

[0054] In the context of the present invention, the term "optically effective" refers to the special characteristic of the cured adhesive of altering one or more optical properties of the composite disc compared to a composite disc without such an optically effective adhesive. In the context of the present invention, the term "additive" refers to a component of the cured adhesive that is added to the base material of the cured adhesive and can be customized. One or more optical properties of the cured adhesive are modified by the optically effective additive with respect to the base material and can be selectively adjusted as desired.

[0055] In one embodiment, the tint (coloration) of at least one section of the adhesive layer of a cured adhesive, and thus of the laminated glass, is set in a predetermined (targeted) manner by means of at least one optically effective additive. For ease of reference, this section is referred to here and in the following as the "tinted section." The tinted section can, in particular, be opaque. Therefore, the adhesive layer can consist of a cured adhesive instead of an opaque masking layer. It can be particularly advantageous if the tinted section is arranged in an edge region of the laminated glass intended as an opaque covering area. This measure advantageously makes it possible to achieve partial opacity of the laminated glass by means of the cured adhesive, which, for this purpose, is sufficiently opaque in at least one section due to a suitable optically effective additive.

[0056] In addition, in an embodiment according to the first aspect of the invention, a reflective layer for light radiation from a projector can be provided, viewed through the laminated glass pane from the inner pane, on the inner side of the tinted section and overlapping the tinted section of the adhesive layer made of a cured adhesive. In an embodiment according to the second aspect of the invention, it is advantageous if the reflective layer for light radiation from a projector, viewed through the laminated glass pane from the inner pane, is arranged on the inner side of the tinted section and overlapping the tinted section of the adhesive layer made of a cured adhesive.

[0057] In one embodiment of the invention, the optical properties of at least one section of the adhesive layer of a cured adhesive, and thus of the composite disc, are predetermined (selectively) adjusted with respect to the reflection of light from an imaging projector by means of at least one optically active additive. For ease of reference, this section is referred to here and subsequently as the "reflection section".

[0058] Advantageously, the cured adhesive with the optically effective additive for adjusting the reflective properties of the adhesive layer achieves a reflectance of at least 10%, at least 40%, at least 50%, or at least 70% of the light incident on the composite lens from an imaging projector. Thus, in an embodiment according to the first aspect of the invention, the adhesive layer made of a cured adhesive can replace the aforementioned reflective layer, particularly on side III of the inner lens, and serve to reflect the image from a projector and thus generate the virtual main image. The reflective section of the adhesive layer designed for light reflection can be located in the HUD area of ​​the composite lens and / or in other areas of the composite lens, particularly overlapping an opaque masking layer.

[0059] In one embodiment, the reflective section of the adhesive layer designed for light reflection (for reflecting the image of an imaging projector) is formed in the HUD area of ​​the composite disc, in particular only in the HUD area of ​​the composite disc.

[0060] In one embodiment, the reflective section of the adhesive layer, designed for light reflection (for reflecting the image from an imaging projector), is arranged, when viewed through the laminated glass, either overlapping or completely within an opaque masking layer, the opaque masking layer being located, in particular, in an upper or lower edge region of the laminated glass. In other words, when viewed through the laminated glass from the outer pane, the reflective section of the adhesive layer is completely obscured by the opaque masking layer. "Viewed through the laminated glass from the outer pane" means looking from the outer pane towards the inner pane. "Viewed through the laminated glass from the inner pane" means looking from the inner pane towards the outer pane.It is understood that when looking through the laminated glass pane from the inner pane, the opaque masking layer is located behind the reflective section of the adhesive layer. The masking layer can be congruent with, i.e., identical to, the reflective section of the adhesive layer, or it can extend beyond the area of ​​the reflective section of the adhesive layer and onto the surface of the laminated glass pane. This advantageously provides a reflective section for the light from an imaging projector through the adhesive layer in the area of ​​the opaque masking layer. The laminated glass pane thus comprises an opaque masking layer and an adhesive layer that is reflective to the incident light radiation from a projector, at least in one section.In one embodiment, instead of the reflective section of the adhesive layer, a reflective layer is provided which, when viewed through the laminated glass pane from the inner pane, is arranged entirely within an opaque masking layer. The other embodiments apply analogously.

[0061] In one embodiment, the optically active additive of the cured adhesive is a dye soluble in the uncured adhesive or an insoluble pigment (consisting of solid particles), wherein the dye or pigment can be freely selected according to the specific circumstances, as long as the dyes are soluble in the uncured adhesive and the pigments are dispersible therein. A multitude of dyes and pigments are known to those skilled in the art, so that further discussion is unnecessary here. In particular, the tint (coloration) of the cured adhesive can be adjusted as desired by means of a dye or pigment, whereby a tint with a visible light transmission of > 0% to < 100% is generally possible. For example, the cured adhesive can be given a black tint by means of a black pigment, for instance to replace black enamel printing.On the other hand, the reflection of the laminated glass pane for visible light can also be adjusted, for example by dispersing metallic particles (e.g., glitter) in the uncured adhesive. For instance, metallic particles are present in the adhesive in such a quantity that the reflection of visible light is at least 10%, at least 40%, at least 50%, or at least 70% of the light incident on the laminated glass pane.

[0062] In one embodiment, the cured adhesive contains particles of aluminum, magnesium, tin, indium, titanium, tantalum, niobium, nickel, copper, chromium, cobalt, iron, manganese, zirconium, cerium, scandium yttrium, silver, gold, platinum, palladium, or ruthenium, or mixtures thereof. Aluminum, titanium, nickel-chromium, and / or nickel have high reflectivity for p-polarized or s-polarized light. They are therefore particularly suitable as components of a projection arrangement in which the image from a projector is reflected by the cured adhesive.

[0063] In one embodiment, light is reflected by the adhesive layer of cured adhesive in equal proportions for p-polarized and s-polarized light, although the reflection of p-polarized and s-polarized light can also vary. The reflection of light by the adhesive layer preferably exhibits a high and uniform reflectance (across different angles of incidence) with respect to p-polarized and / or s-polarized radiation, thus ensuring a high-intensity and color-neutral image representation. When p-polarized light is reflected, fewer ghost images occur, resulting in improved visual quality of the reflected light (e.g., virtual image). The reflectance can be increased by adding s-polarized light.The reflectance is measured at an angle of incidence of 65° to the interior surface normal (interior surface of the inner disc), which corresponds approximately to the illumination by conventional HUD projectors. With a reflective layer applied to side III, light reflection preferably occurs only for p-polarized light. With a reflective layer applied to side IV, light reflection preferably occurs for both p-polarized and s-polarized light, particularly in equal proportions.

[0064] Reflectance describes the proportion of the total incident radiation that is reflected. It is expressed as a percentage (relative to 100% incident radiation) or as a dimensionless number from 0 to 1 (normalized to the incident radiation). The data on reflectance and the reflection spectrum refer to a reflection measurement with a light source that emits uniformly across the considered spectral range at a normalized radiation intensity of 100%.

[0065] The reflective section of the adhesive layer preferably extends over a maximum of 30%, and more preferably over a maximum of 20%, of the surface of the laminated glass. The reflective section of the adhesive layer is particularly preferably located in an upper edge region of the laminated glass adjacent to the top edge and / or in a lower edge region adjacent to the bottom edge. Alternatively, the reflective section can also be located additionally or exclusively in a lateral edge region adjacent to one or both side edges of the laminated glass. The reflective section preferably extends in a strip shape from one (left) side edge to the other (right) side edge and is particularly adjacent to the bottom edge of the laminated glass. The reflective section preferably has a width of at least 10 cm, more preferably at least 20 cm, and more preferably at least 30 cm.The arrangement of the reflective section in an edge area adjacent to the lower edge, left side edge, right side edge and / or upper edge is particularly suitable when the laminated glass is designed in the form of a vehicle window, especially a windshield, as this keeps the area of ​​the laminated glass intended for viewing clear.

[0066] The adhesive layer of a cured adhesive can be formulated with at least one optically active additive that imparts reflective properties, but only in a specific section of the adhesive layer (i.e., the reflective section). However, it is also possible for the entire adhesive layer to contain at least one such optically active additive. The same applies to optically active additives that impart other optical properties, such as, in particular, the opacity of the adhesive layer.

[0067] The optical properties of the adhesive layer made from a cured adhesive with at least one optically effective additive preferably relate to visible light, i.e., light in a wavelength range of approximately 380 nm to 780 nm.

[0068] The present invention thus advantageously demonstrates a new way in which the optical properties of a laminated glass pane can be selectively adjusted in a predetermined manner by conditioning the adhesive layer contained in the intermediate layer, consisting of a cured adhesive, in at least one section with at least one optically active additive. In other words, the optical properties of the adhesive layer, consisting of a cured adhesive, are selectively adjusted in a predetermined manner by at least one optically active additive in order to selectively influence the optical properties of the laminated glass pane. This applies particularly to the reflection properties of laminated glass panes, which is a major advantage of the present invention.

[0069] The two panes of the laminated glass can, in principle, have any chemical composition known to a person skilled in the art. The two panes preferably contain or consist of glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass, or aluminosilicate glass. It is also conceivable that the two panes contain or consist of a clear plastic, preferably a rigid clear plastic, in particular polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, polystyrene, polyamide, polyester, polyvinyl chloride, and / or mixtures thereof.

[0070] In one embodiment of the invention, the laminated glass pane contains or consists of glass. The thickness of each individual pane of the laminated glass pane can vary widely and be adapted to the requirements of the specific application. Preferably, panes with standard thicknesses of 0.5 mm to 25 mm and more preferably from 0.5 mm to 5 mm are used. The size of the panes can vary widely and depends on their intended use. The laminated glass pane can have any three-dimensional shape and be planar or curved in one or more directions in space.

[0071] The two panes of the composite glass are firmly bonded together by an intermediate layer, which in any case contains an adhesive layer of a cured adhesive. According to the first aspect of the invention and optionally according to the second aspect of the invention, the intermediate layer contains at least one plastic layer made of a thermoplastic material. The plastic layer made of a thermoplastic material preferably contains or consists of polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), thermoplastic polyurethane (TPU), polyethylene terephthalate (PET), or mixtures or copolymers or derivatives thereof, particularly preferably PVB. The at least one plastic layer made of a thermoplastic material is typically formed by one or more thermoplastic films arranged one above the other, the thickness of each thermoplastic film preferably being from 0.2 mm to 1 mm, for example 0.38 mm or 0.76 mm.

[0072] In one embodiment, the thermoplastic layer is an acoustically damping layer. This layer typically comprises at least two outer polymer layers and at least one inner polymer layer between them, the inner polymer layer exhibiting greater plasticity or elasticity than the outer polymer layers. This results in an acoustically damping intermediate layer with a soft core, while the stiffness of the layer structure increases from the core to the edge. The inner polymer layer has, for example, a thickness of 0.05 mm to 0.40 mm, and the outer polymer layers have, for example, a thickness of 0.20 mm to 0.60 mm. Acoustically damping layers made of thermoplastic material are known in the art, see, for example, WO 2017 / 055470 A1, so they need not be discussed in detail here.

[0073] In one embodiment, the thermoplastic layer is an infrared (IR) reflecting layer, an infrared (IR) absorbing layer, a UV (UV) absorbing layer, and / or a layer that is at least partially tinted or colored. Such layers are known in the trade and are used as standard, e.g., in vehicle windows, so that further embodiments are unnecessary.

[0074] When multiple layers of thermoplastic material are present, they can also have different functions.

[0075] The two panes of the composite pane and / or the intermediate layer, in particular the adhesive layer made of a cured adhesive and / or at least one plastic layer made of a thermoplastic material, present according to the first aspect of the invention and optionally present according to the second aspect of the invention, can be clear and colorless, but also tinted or colored.

[0076] For the purposes of the present invention, "transparent" means that the overall transmission of the laminated glass complies with the legal requirements in the European Union for windshields and front side windows and preferably has a transmission of more than 70% and, in particular, more than 75% for visible light. For rear side windows, roof windows, and rear windows, "transparent" can also mean a light transmission of 10% to 70%. Similarly, "opaque" means a light transmission of less than 15%, preferably less than 5%, and in particular, 0%.

[0077] In one embodiment, the adhesive layer, consisting of a cured adhesive, has a refractive index that differs from the refractive index of the two panes by less than 50%, preferably less than 30%, and more preferably less than 10%. This can be advantageous for the optical properties of the laminated pane.

[0078] The composite disc according to the invention can be part of a projection arrangement, wherein the HUD area of ​​the composite disc can be illuminated with light beams from an imaging projector. According to the first aspect of the invention, the image from the imaging projector is reflected as the primary image (primary reflection) from the inner surface of the inner disc (side IV), or according to the second aspect of the invention, from a reflective layer on side III or side IV. Reflection is also possible at the adhesive layer of a cured adhesive, which is provided with reflective properties by at least one optically active additive. If the HUD area is illuminated by a projector, for example, up to 30%, in particular up to 20%, and in particular up to 15% of the visible light from the projector incident on the HUD area is reflected.

[0079] The invention further relates to a projection arrangement comprising a composite disc according to the invention and at least one (image-generating) projector which projects an image in the form of visible radiation, preferably via the inner disc, onto the HUD area of ​​the composite disc.

[0080] In an embodiment according to the first aspect of the invention, an image is projected onto the HUD area by the imaging projector, whereby a primary reflection of the image emitted by the projector occurs on the inner surface of the inner disc (side IV), thereby creating the virtual main image, and a virtual secondary image is generated by a secondary reflection on the outer surface of the outer disc (side I). The wedge-shaped intermediate layer in the HUD area at least approximates, and in particular superimposes, the main and secondary images in order to avoid or at least reduce disturbing optical effects.

[0081] In one embodiment, an image is projected onto the HUD area by the imaging projector. A primary reflection of the image emitted by the projector occurs at a reflective layer applied to the outer surface of the inner disk (side III), creating the virtual main image. Secondary reflections at the outer surface of the outer disk (side I) and at the inner surface of the inner disk (side IV) generate virtual secondary images. The wedge-shaped intermediate layer in the HUD area at least approximates, and in particular superimposes, the main image and the secondary image generated by secondary reflection at side I, in order to avoid or at least reduce disturbing optical effects. The secondary image generated by secondary reflection at side IV can be prevented by an anti-reflective layer applied to side IV.

[0082] In one embodiment of the preceding embodiment relating to the first aspect of the invention, instead of the reflective layer, at least one section of the adhesive layer is provided with at least one optically active additive in a cured adhesive, such that the section has light-reflecting properties with respect to the light radiation of the imaging projector. This section extends, in view through the composite lens, at least over the HUD area. In another embodiment relating to the preceding embodiment relating to the second aspect of the invention, in addition to the reflective layer, at least one section of the adhesive layer is provided with at least one optically active additive in a cured adhesive, such that the section has light-reflecting properties with respect to the light radiation of the imaging projector.The section extends, when viewed through the composite glass, at least over the HUD area.

[0083] In a further embodiment, an image is projected onto the HUD area by the imaging projector. A primary reflection of the image emitted by the projector occurs at a reflective layer applied to the inner surface of the inner disc (side IV), creating the virtual main image. A secondary reflection at the outer surface of the outer disc (side I) generates a virtual secondary image. The wedge-shaped intermediate layer in the HUD area at least approximates, and in particular superimposes, the main image and the secondary image generated by secondary reflection at side I, in order to avoid or at least reduce disturbing optical effects.

[0084] In a further embodiment, at least one section of the adhesive layer, consisting of a cured adhesive, is provided with at least one optically active additive, such that the section exhibits light-reflecting properties with respect to the light emission from the imaging projector. An image is projected from the imaging projector onto the light-reflecting section of the adhesive layer, resulting in a primary reflection of the image emitted by the projector, thus creating the virtual main image. When viewed through the composite pane from the inner pane, the section of the adhesive layer containing the optically active additive is completely enclosed within an opaque masking layer. This has the advantage that the virtual image can be perceived visually with high contrast.

[0085] In a variant of the immediately preceding embodiment with regard to the first aspect of the invention, instead of the reflective section of the adhesive layer, a reflective layer is provided which, when viewed through the composite disc from the inner disc, is arranged completely within an opaque masking layer.

[0086] The image-generating projector is preferably oriented towards the interior surface of the inner pane. If the laminated pane is installed (for example, as a windshield in a vehicle), the projector illuminates the HUD area or the light-reflecting section of the adhesive layer from an interior space (vehicle interior).

[0087] For the overall intensity of the HUD image, it can be advantageous if the projector's radiation contains both s-polarized and p-polarized components. However, it is also possible that the p-polarized component of the projector is 100%, meaning the projector emits purely p-polarized radiation. This depends on the specific primary reflection mechanism, whereby a reflective layer on side III generally reflects only p-polarized radiation. Advantageously, the p-polarized component of the projector's radiation should be at least 50%, which ensures, in particular, that a driver wearing polarization-selective sunglasses can perceive a high-intensity image.

[0088] If the projection system is part of a vehicle, the at least one projector is preferably located in the vehicle's dashboard. The image projected by the projector is reflected by the laminated windscreen into the vehicle interior, for example, into the field of vision of an occupant.

[0089] The projector is preferably a Liqiud crystal (LCD) display, thin film transistor (TFT) display, light emitting diode (LED) display, organic light emitting diode (OLED) display, electroluminescent (EL) display or microLED display.

[0090] The beam direction of the at least one projector can typically be varied by mirrors, particularly vertically, to adjust the projection to the viewer's height. The area in which the viewer's eyes must be located for a given mirror position is called the eyebox. This eyebox can be shifted, especially vertically, by adjusting the mirrors. A viewer located within the eyebox can perceive the virtual image (main image and secondary image). This means that the viewer's eyes must be within the eyebox, not their entire body.

[0091] The composite disc according to the invention can be produced by a method comprising a step for providing an outer disc and an inner disc, and a step for connecting the outer disc and the inner disc by means of an at least partially wedge-shaped intermediate layer, wherein the intermediate layer contains at least one adhesive layer made of a curable or cured adhesive, wherein the adhesive layer made of a curable or cured adhesive is wedge-shaped at least in the HUD area.

[0092] For laminating the composite disc, known methods for manufacturing composite discs can be used. For example, autoclave processes can be carried out at elevated pressures of approximately 1 bar to 15 bar and temperatures of 100 °C to 145 °C for about 2 hours. Known vacuum bag or vacuum ring processes operate, for example, at approximately 200 mbar and 130 °C to 145 °C. The two discs can also be pressed together in a calender between at least one pair of rollers to form a composite disc. Plants of this type are known for manufacturing composite discs and typically have at least one heating tunnel upstream of a press. The temperature during the pressing process is, for example, from 40 °C to 150 °C. Combinations of calender and autoclave processes have proven particularly effective in practice. Alternatively, vacuum laminators can be used.These consist of one or more heated and evacuated chambers in which the first and second panes can be laminated within, for example, approximately 60 minutes at a reduced pressure of 0.01 mbar to 800 mbar and temperatures of 80°C to 170°C. This is well known to those skilled in the art, so it need not be discussed in more detail here.

[0093] The above descriptions of the composite disc and projection arrangement according to the invention apply analogously to the method for manufacturing them. Similarly, the descriptions of the method apply analogously to the composite disc and projection arrangement.

[0094] The composite glass according to the invention can be used in buildings or in means of transport for travel on land, in the air or on water, in particular in motor vehicles, for example as a windshield, rear window, side windows and / or roof window. The use of the composite glass in motor vehicles is preferred, especially as a windshield or roof window.

[0095] As can be seen in particular from the above explanations, the first aspect of the invention comprises: A composite pane for a projection arrangement with a HUD area (H) for separating an interior from an external environment, comprising an outer pane and an inner pane which are firmly connected to each other by an intermediate layer, wherein the intermediate layer is wedge-shaped at least in the HUD area of ​​the composite pane, wherein the intermediate layer contains at least one plastic layer made of a thermoplastic material and at least one adhesive layer made of a cured adhesive, wherein the at least one adhesive layer is wedge-shaped at least in the HUD area and wherein the plastic layer made of a thermoplastic material does not have a wedge shape.

[0096] Furthermore, the composite disc according to the first aspect of the invention comprises the following preferred embodiments: - an embodiment in which the adhesive layer made of a cured adhesive has the same area as the plastic layer made of a thermoplastic material; - an embodiment in which the at least one adhesive layer made of a cured adhesive is wedge-shaped over the entire surface of the composite disc, wherein in particular a wedge angle (β) of the adhesive layer made of a cured adhesive is from 0.3 mrad to 0.7 mrad, preferably from 0.4 mrad to 0.5 mrad; - an embodiment in which a reflective layer for reflecting light from a projector is arranged on an outer surface of the inner disc or on an inner surface of the inner disc; - an embodiment in which the at least one adhesive layer made of a cured adhesive has at least one optically effective additive by which optical properties of the composite disc are adjusted with respect to reflection, transmission, tinting and / or absorption of light; - an embodiment in which the at least one adhesive layer made of a cured adhesive has at least one reflective section with at least one optically effective additive for reflecting light from a projector; - an embodiment in which the reflection section, viewed from the inner pane, is arranged completely within an opaque masking layer, wherein the opaque masking layer is arranged in particular in an upper or lower edge region of the composite pane; - an embodiment in which the at least one adhesive layer made of a cured adhesive has at least one, in particular opaque, tinted section with at least one optically effective additive, wherein the tinted section is optionally arranged in an upper or lower edge region of the laminated pane, and wherein, optionally, in view through the laminated pane from the inner pane, a reflective layer is arranged completely within the tinted section.

[0097] The various embodiments of the composite disc according to the first aspect of the invention can be realized individually or in any combination.

[0098] According to the first aspect of the invention, a projection arrangement is further comprised, comprising - a composite disc as described above according to the first aspect of the invention, - at least one projector that projects visible radiation onto the composite glass.

[0099] Furthermore, the projection arrangement according to the first aspect of the invention comprises the following preferred embodiment of a projection arrangement with a composite disc which has a reflective section which, when viewed through the composite disc from the inner disc, is arranged completely within an opaque masking layer, wherein the opaque masking layer is arranged in particular in an upper or lower edge region of the composite disc, wherein one projector serves to project visible radiation onto the HUD area (H), and another projector serves to project visible radiation onto the reflective section.

[0100] As can be seen in particular from the above explanations, the second aspect of the invention comprises: A composite pane for a projection arrangement with a HUD area (H) for separating an interior from an external environment, comprising an outer pane and an inner pane which are firmly connected to each other by an intermediate layer, wherein a reflective layer for reflecting light from a projector is arranged on an outer surface of the inner pane or on an interior surface of the inner pane, wherein the intermediate layer is wedge-shaped at least in the HUD area of ​​the composite pane, and wherein the intermediate layer contains at least one adhesive layer of a cured adhesive, wherein the at least one adhesive layer is wedge-shaped at least in the HUD area (H).

[0101] Furthermore, the composite disc according to the second aspect of the invention comprises the following preferred embodiments: - an embodiment in which the intermediate layer contains at least one plastic layer made of a thermoplastic material and at least one adhesive layer made of a cured adhesive; - an embodiment in which the at least one plastic layer made of a thermoplastic material does not have a wedge shape; - an embodiment in which the at least one plastic layer made of a thermoplastic material has a wedge shape; - an embodiment in which the adhesive layer made of a cured adhesive has an area equal to that of the at least one plastic layer made of a thermoplastic material; - an embodiment in which the outer pane and the inner pane are firmly connected to each other only by the at least one adhesive layer made of a cured adhesive; - an embodiment in which the at least one adhesive layer made of a cured adhesive is wedge-shaped over the entire surface of the composite disc, wherein in particular a wedge angle (β) of the adhesive layer made of a cured adhesive is from 0.3 mrad to 0.7 mrad, preferably from 0.4 mrad to 0.5 mrad; - an embodiment in which the at least one adhesive layer made of a cured adhesive has at least one optically effective additive by which optical properties of the composite disc are adjusted with respect to reflection, transmission, tinting and / or absorption of light; - an embodiment in which the at least one adhesive layer made of a cured adhesive has at least one reflective section with at least one optically effective additive for reflecting light from a projector; - an embodiment in which the reflection section, viewed from the inner pane, is arranged completely within an opaque masking layer, wherein the opaque masking layer is arranged in particular in an upper or lower edge region of the composite pane; - an embodiment in which the at least one plastic layer made of a cured adhesive has at least one, in particular opaque, tinted section with at least one optically effective additive, wherein the tinted section is optionally arranged in an upper or lower edge region of the composite pane, and wherein, optionally, in view through the composite pane from the inner pane, the reflective layer is arranged completely within the tinted section;

[0102] The various embodiments of the composite disc according to the second aspect of the invention can be realized individually or in any combination.

[0103] According to the second aspect of the invention, a projection arrangement is further included, comprising - a composite disc as described above according to the second aspect of the invention, - at least one projector that projects visible radiation onto the composite glass.

[0104] Furthermore, the projection arrangement according to the second aspect of the invention comprises the following preferred embodiment of a projection arrangement with a composite disc which has a reflective section which, when viewed through the composite disc from the inner disc, is arranged completely within an opaque masking layer, wherein the opaque masking layer is arranged in particular in an upper or lower edge region of the composite disc, wherein one projector serves to project visible radiation onto the HUD area (H), and another projector serves to project visible radiation onto the reflective section.

[0105] The various embodiments of the invention can be implemented individually or in any combination. In particular, the features mentioned above and explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the present invention.

[0106] The invention is explained in more detail below with reference to exemplary embodiments, with reference to the accompanying figures. These show, in a simplified representation not to scale: Fig. 1 an embodiment of the composite disc according to the invention in a top view, Fig. 2 a cross-sectional view of a projection arrangement with an embodiment of the composite disk of Fig. 1, which is designed according to the first aspect of the invention, Fig. 3 a cross-sectional view of a projection arrangement with a further embodiment of the composite disk made of Fig. 1, which is not claimed in the claims for protection, Fig. 4 an enlarged lower edge area of ​​the projection arrangement made of Fig. 2 in a cross-sectional view, Fig. 5 an enlarged lower edge area of ​​the projection arrangement made of Fig. 3 in a cross-sectional view, Fig. 6 Another embodiment of the composite disc in a cross-sectional view in an analogous representation to Fig. 5, which is designed according to the second aspect of the invention, Fig. 7 an enlarged HUD area of ​​the projection arrangement Fig. 2 in a cross-sectional view, Fig. 8 an enlarged HUD area of ​​the projection arrangement Fig. 2 with a further embodiment of the composite disk in a cross-sectional view, which is designed according to the first aspect of the invention, Fig. 9 an enlarged HUD area of ​​the projection arrangement Fig. 2 with a further embodiment of the composite disk in a cross-sectional view, which is designed according to the first aspect of the invention, Fig. 10 a flowchart of an exemplary embodiment of the method.

[0107] Fig. Figure 1 shows an embodiment of the composite glass 1 according to the invention in the form of a windshield for a vehicle. The composite glass 1 is shown in a top view, looking at an interior surface (side IV) of the composite glass 1. Fig. Figure 2 shows an embodiment of the composite disc 1 as a component of a projection arrangement 100 according to the invention in a cross-sectional view, wherein the projection arrangement 100 is installed in a vehicle. The composite disc 1 of Fig. 2 is designed according to the first aspect of the invention. The cross-sectional view of the Fig. 2 corresponds to the section line AA' of the composite disk 1, as shown in Fig. 1 is indicated. Fig. 3 shows analogous to Fig. 2 another embodiment of the composite disc 1 as part of a projection arrangement 100 in a cross-sectional view, which is not claimed in the claims. Fig. Figure 4 shows an enlarged section of the projection setup 100. Fig. 2, wherein the enlarged section shows a lower edge area 7.2 adjacent to the lower edge of the composite disc 1. Fig. Figure 5 shows an enlarged section of the projection setup 100 from Fig. 3, wherein the enlarged section shows a lower edge area 7.2 adjacent to the lower edge of the composite disc 1. Fig. Figure 6 shows an enlarged section of projection setup 100. Fig. 3 with a further embodiment of the composite disc 1, wherein the enlarged section shows a lower edge region 7.2 adjacent to the lower edge of the composite disc 1. The composite disc 1 of Fig. 6 is designed according to the second aspect of the invention. Fig. Figure 7 shows an enlarged section of the projection setup 100 from Fig. 2, where a view through the composite lens 1 with a HUD area H is shown. Fig. 8 and Fig. Figure 9 shows an enlarged HUD area of ​​the projection setup. Fig. 2 with further embodiments of the composite disc in a cross-sectional view, which are designed according to the first aspect of the invention.

[0108] The composite pane 1 has a top edge and a bottom edge, as well as two side edges connecting the top and bottom edges (all together forming a circumferential edge of the composite pane 1). The bottom edge (also called the motor edge) of the composite pane 1 is the edge that faces the ground when installed. The top edge (also called the roof edge) of the composite pane 1 is the edge that faces the vehicle roof when installed in a vehicle.

[0109] The laminated glass 1 comprises an outer pane 2, an inner pane 3, and an intermediate layer 4 arranged between the outer pane 2 and the inner pane 3. The outer pane 2 has an outer surface I facing away from the intermediate layer 4 and an inner surface II facing the intermediate layer 4. The inner pane 3 has an outer surface III facing the intermediate layer 4 and an inner surface IV facing away from the intermediate layer 4. The outer surface I of the outer pane 2 is also the surface of the laminated glass 1 facing the external environment 16, and the inner surface IV of the inner pane 3 is also the surface of the laminated glass 1 facing the interior 15 of the vehicle. The laminated glass 1 has, for example, a shape and curvature typical for windshields.

[0110] The outer pane 2 and the inner pane 3 each consist of glass, preferably thermally tempered soda-lime glass, and are transparent to visible light. The outer pane 2 has, for example, a thickness of 2.1 mm and the inner pane 3, for example, a thickness of 1.5 mm. The intermediate layer 4 is wedge-shaped, with the thickest part of the intermediate layer 4 located at the top edge of the laminated pane 1 and the thinnest end located at the bottom edge of the laminated pane 1. The wedge angle β of the intermediate layer 4 is, for example, 0.2 mrad. In accordance with the invention, an embodiment in which the intermediate layer 4 is wedge-shaped only in the HUD region H and otherwise has a constant thickness would also be possible (not shown here).

[0111] An opaque masking layer 5 is applied to the interior surface II of the outer pane 2. A further opaque masking layer 5' is applied to the interior surface IV of the inner pane 3. This further masking layer 5' extends in a frame-like fashion along the perimeter edge of the laminated pane 1. The masking layer 5 is widened in the lower edge region 7.2, directly adjacent to the lower edge of the laminated pane 1. The masking layer 5 and the further masking layer 5' are opaque and prevent the view of structures located on the inside or outside of the laminated pane 1, for example, an adhesive bead for bonding the laminated pane 1 into a vehicle body. The masking layer 5 and the further masking layer 5' consist of a conventionally used, electrically non-conductive material, such as a black-tinted screen printing ink that has been baked on.

[0112] The laminated glass panel 1 has a HUD area H, which is designed to display a head-up display image for a driver or passenger of the vehicle. The HUD area H is located in the viewing area of ​​the laminated glass panel 1, so that an image projected onto the HUD area H can be perceived by a viewer as if it were appearing behind the laminated glass panel 1 (i.e., in the external environment 16).

[0113] In the embodiment according to the first aspect of the invention of Fig. 2. The intermediate layer 4 comprises an adhesive layer 8 made of a cured adhesive and a plastic layer 9 made of a thermoplastic material. The intermediate layer 4 consists of the adhesive layer 8 and the plastic layer 9. The adhesive layer 8 preferably contains or consists of polyurethane, polyacrylate, polyacetate resin, casting resin, silicone, or a mixture thereof. The plastic layer 9 contains or consists of a thermoplastic material, preferably polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), and / or polyethylene terephthalate (PET).

[0114] In the embodiment of Fig. 3, which is not claimed in the claims, the intermediate layer 4 consists only of an adhesive layer 8 made of a cured plastic.

[0115] In the exemplary embodiments of the Fig. 2 and Fig. 3 The adhesive layer 8 has a wedge shape in each case. In the exemplary embodiment of Fig. In the embodiment of 2, the plastic layer 9 is not wedge-shaped. The intermediate layer 4 is thus formed wedge-shaped solely by the wedge-shaped adhesive layer 8. Fig. In 3, the intermediate layer 4 only has the adhesive layer 8, so that the wedge shape of the intermediate layer 4 results exclusively from the wedge shape of the adhesive layer 8.

[0116] In the exemplary embodiments of the Fig. 2 and Fig. 3 is a section of the adhesive layer 8, hereinafter referred to as "reflection section 6" for ease of reference, provided with reflective properties by the addition of at least one optically active additive. This can be seen from the enlarged illustrations of the Fig. 4 and Fig. The reflective section 6 is clearly visible. When viewed through the laminated glass 1 from the interior 15, it is completely overlapped with the opaque masking layer 5 in the lower edge region 7.2 of the laminated glass 1, meaning it is located closer to the bottom edge than to the top edge of the laminated glass 1. When installed in a vehicle, the reflective section 6 is located in the vicinity of the dashboard 17. The reflective section 6 extends from the left side edge to the right side edge of the laminated glass 1. Therefore, the reflective section 6 is located in front of the masking layer 5 on the vehicle interior side. It is understood that the masking layer 5 completely obscures the reflective section 6 when viewed through the laminated glass 1 from the external environment 16. The reflective section 6 is located outside of any viewing area and the HUD area H of the laminated glass 1.Reflection section 6 can be opaque or transparent.

[0117] The reflective section 6 is formed by at least one optically active additive in the cured adhesive, which modifies the optical properties of the adhesive layer 8 with respect to the reflection of light, for example by metallic particles that are finely dispersed in the cured adhesive. The reflective section 6 is, for example, designed to reflect at least 30%, preferably at least 50%, and particularly preferably at least 70% of visible light.

[0118] As in the Fig. 2 and Fig. As shown in Figure 3, a projector 12 and another projector 13 are arranged on a dashboard 17 of the vehicle, each of which can project images in the form of visible radiation (light) 14.1, 14.2 onto the composite disc 1.

[0119] As in Fig. 7 for the embodiment of the composite disc of Fig. As shown in Figure 2, the projector 12 projects visible radiation 14.1 onto the HUD area of ​​the composite disc 1. This radiation is reflected as a primary reflection from the inner surface of the inner disc 2 (side IV), creating the virtual main image (HUD image) for the viewer. A secondary reflection also occurs at the outer surface of the outer disc 2 (side I), generating a virtual secondary image (not shown). The wedge-shaped intermediate layer 4 in the HUD area superimposes or at least approximates the main and secondary images to avoid or at least reduce disruptive optical effects. The HUD area H illuminated by the projector 12 is defined by a dashed trapezoidal area on the composite disc 1. Fig. 1 indicated.

[0120] As in Fig. 4 for the embodiment of the composite disc 1 of Fig. 2 and in Fig. 5 for the embodiment of the composite disc 1 of Fig. Figure 3, shown enlarged, shows that the projector 13 projects visible radiation 14.2 onto the reflective section 6 of the adhesive layer 8 of the composite disc 1. This radiation is reflected by the reflective section 6 as a primary reflection, thus creating the virtual main image (HUD image) for the viewer. No secondary reflection occurs on the outer surface of the outer disc 2 (side I) because this is prevented by the opaque masking layer 5. Any potential virtual secondary image generated by reflection on the inner surface of the inner disc 3 (side IV) can be counteracted by an anti-reflective layer on side IV (not shown). The HUD image can be displayed with high contrast due to the opaque masking layer 5. The reflective section 6 illuminated by the additional projector 13 is indicated by a dashed, striped area on the composite disc 1. Fig. 1 indicated.

[0121] The reflection angle α for light projected onto the composite disk 1 by projectors 12 and 13 is, for example, 65°. Projector 12 and projector 13 are, for example, light-emitting diode displays (LED displays).

[0122] As in Fig. As illustrated in an enlarged view of an embodiment according to the second aspect of the invention, a tinting section 10 of the adhesive layer 8 can be provided instead of a reflective section 6. In this section, for example, a tinting pigment (solid particle) is dispersed in the cured adhesive as an optically active additive, so that the composite pane 1 is tinted, for example, gray or copper-colored in the tinting section 10, depending on the type of pigment used. In the present embodiment, the tinting section 10 is preferably black and replaces the opaque masking layer 5. In addition, a reflective layer 11 is applied in certain areas to the interior surface of the inner pane 3 (side IV). Viewed through the composite pane 1 from the interior 15, this layer overlaps the tinting section 10 in the lower edge region 7.The reflective layer 11 is located closer to the lower edge than to the upper edge of the laminated glass 1. When installed in a vehicle, the reflective layer 11 is positioned in the vicinity of the dashboard 17. The reflective layer 11 extends from the left side edge to the right side edge of the laminated glass 1. Therefore, the reflective layer 11 is located in front of the tinted section 10 on the vehicle interior side. Conversely, it is understood that the tinted section 10 completely obscures the reflective layer 11 when viewed through the laminated glass 1 from the external environment 16. The reflective layer 11 is located outside of any viewing area intended for use through the laminated glass 1 and outside the HUD area H of the laminated glass 1. The reflective layer 11 is, for example, a dielectric stack containing TiO2 and SiO2 layers.The reflective layer 11 is applied, for example, by magnetron sputtering to the inner surface of the inner disk 3 (side IV). The reflective layer 11 is designed, for example, to reflect at least 30%, preferably at least 50%, and particularly preferably at least 70% of visible light.

[0123] As in Fig. As shown in Figure 6, the projector 13 projects visible radiation 14.2 onto the reflective layer 11 of the composite disc 1, which is reflected by the reflective layer 11 as primary reflection, thus creating the virtual main image (HUD image) for the viewer. No secondary reflection occurs. The HUD image can be displayed with high contrast due to the opaque tinted section 10. The reflective layer 11 illuminated by the additional projector 13 is indicated by a dashed, striped area on the composite disc 1. Fig. 1 indicated.

[0124] In the cured adhesive of adhesive layer 8, a coloring pigment and / or metallic particles are preferably used as optically effective additives. The curable adhesive can be processed in film or liquid form. Curing is preferably achieved by heat and / or UV light.

[0125] In an embodiment not shown, an adhesive layer made of an optically effective adhesive surrounds a thermoplastic layer and is located only in the edge region of the laminated lens, including the HUD area. The cured adhesive can be poured in liquid form into the edge region of the already laminated lens and then cured, for example, by heat and / or UV light.

[0126] In the Fig. 8 and Fig. 9 are analogous to enlarged cross-sectional views in the HUD area. Fig. Seven further embodiments of the composite disk 1 according to the first aspect of the invention are illustrated. Only the differences from the embodiment of [reference to embodiment] are shown. Fig. Section 7 explains this, and otherwise reference is made to the explanations given there.

[0127] In Fig. 8 A reflective layer 11 is applied to the outer surface of the inner disc 3 (side III), which is designed to reflect light radiation 14.1 from the projector 12. The reflection of light radiation 14.1 at the reflective layer 11 creates the virtual main image. Secondary reflections of the incident light radiation 14.1 at the outer surface of the outer disc 2 (side I) and at the inner surface of the inner disc 3 (side IV) create virtual secondary images. The wedge-shaped intermediate layer 4 in the HUD area superimposes or at least approximates the main image and the secondary image generated by reflection at side I. The secondary image generated by reflection at side IV can be prevented by an antireflection layer 18 applied to side IV.

[0128] In Fig. 9 A reflective layer 11 is applied to the inner surface of the inner disc 3 (side IV), which is designed to reflect light radiation 14.1 from the projector 12. The reflection of light radiation 14.1 at the reflective layer 11 creates the virtual main image. Secondary reflections of the incident light radiation 14.1 at the outer surface of the outer disc 2 (side I) create a virtual secondary image. The wedge-shaped intermediate layer 4 in the HUD area superimposes, or at least approximates, the main image and the secondary image generated by reflection at side I.

[0129] In Fig. Figure 10 shows a flowchart of the process for manufacturing the composite disc according to the invention.

[0130] The process for manufacturing a composite disk according to the first aspect of the invention comprises the following steps: a) Providing an outer pane and an inner pane, b) Connecting the outer pane and the inner pane by an intermediate layer, wherein the intermediate layer is wedge-shaped at least in the HUD area of ​​the composite pane, wherein the intermediate layer contains at least one plastic layer made of a thermoplastic material and at least one adhesive layer made of a curable or cured adhesive, wherein the at least one adhesive layer is wedge-shaped at least in the HUD area (H) and wherein the plastic layer made of a thermoplastic material does not have a wedge shape.

[0131] The process for manufacturing a composite disk according to the second aspect of the invention comprises the following steps: a) Providing an outer pane and an inner pane, wherein a reflective layer for reflecting light from a projector is arranged on an outer surface of the inner pane or on an inner surface of the inner pane; b) Connecting the outer pane and the inner pane by means of an intermediate layer that is at least partially wedge-shaped, wherein the intermediate layer contains at least one adhesive layer with a curable or cured adhesive, wherein the adhesive layer is wedge-shaped at least in the HUD area (H).

[0132] From the above explanations, it follows that the invention provides an improved composite disc whose wedge shape and optical properties can be selectively adjusted in a predetermined manner by the adhesive layer of cured adhesive contained in the intermediate layer. This enables the cost- and time-efficient production of composite discs with a wedge-shaped intermediate layer using industrially available production equipment, whereby the production of the composite disc can be easily implemented in common manufacturing processes. Reference sign 1 composite disc 2 Outer pane 3 inner disc 4 Intermediate layer 5 masking layer 5' additional masking layer 6 Reflection section 7.1 upper edge area of ​​the composite disc 1 7.2 lower edge area of ​​the composite disc 1 8 adhesive layer made of a cured adhesive 9 plastic layer made of a thermoplastic material 10 tinting section 11 Reflective layer 12-inch projector 13 more projectors 14.1 Visible radiation of the projector 12 14.2 Visible radiation from the other projector 13 15 Interior 16 external environment 17 Dashboard 18 Anti-reflective coating 100 Projection setup H HUD area α Angle of reflection β Wedge angle I outer surface of the outer pane 2 II Interior surface of the outer pane 2 III outer surface of the inner pane 3 IV Interior surface of the inner pane 3 AA' Intersection line QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2009 / 071135 A1

[0005] EP 1800855 B1

[0005] EP 1880243 A2

[0005] DE 102009020824 A1

[0008] WO 2022 / 131097 A1

[0009] WO 2018 / 208347 A1

[0009] WO 2018 / 208348 A1

[0009] DE 102014220189 A1

[0041] US 2017242247 A1

[0041] WO 2019046157 A1

[0041] WO 2019179682 A1 [0041, 0047] WO 2019179683 A1 [0041, 0047] WO 2019206493 A1

[0047] US 20190064516 A1

[0047] WO 2017 / 055470 A1

[0072]

Claims

[1] Composite screen (1) for a projection arrangement (100) with a HUD area (H) for separating an interior space (15) from an external environment (16), comprising an outer screen (2) and an inner screen (3) which are firmly connected to each other by an intermediate layer (4), wherein the intermediate layer (4) is wedge-shaped at least in the HUD area of ​​the composite screen, wherein the intermediate layer (4) comprises at least one plastic layer (9) made of a thermoplastic material and at least one adhesive layer (8) made of a cured adhesive,wherein the at least one adhesive layer (8) is wedge-shaped at least in the HUD area (H) and wherein the plastic layer (9) made of a thermoplastic material does not have a wedge shape and wherein a reflective layer (11) for reflecting light from a projector (12) is arranged on an outer surface of the inner disc (3) or on an inner surface of the inner disc (3) or the at least one adhesive layer (8) made of a cured adhesive has at least one reflective section (6) with at least one optically active additive for reflecting light from a projector (13). [2] Composite disc (1) according to claim 1, in which the adhesive layer (8) made of a cured adhesive has an area equal to that of the plastic layer (9) made of a thermoplastic material. [3] Composite disc (1) according to one of claims 1 or 2, in which the at least one adhesive layer (8) made of a cured adhesive is wedge-shaped over the entire surface of the composite disc (1), wherein in particular a wedge angle (β) of the adhesive layer (8) made of a cured adhesive (4) is from 0.3 mrad to 0.7 mrad, preferably from 0.4 mrad to 0.5 mrad. [4] Composite disc (1) according to claim 1, in which the reflection section (6) is arranged completely within an opaque masking layer (5) when viewed through the composite disc (1) from the inner disc (3), wherein the opaque masking layer (5) is arranged in particular in an upper or lower edge region (7.1, 7.2) of the composite disc (1). [5] Projection arrangement (100), comprising - a composite disc (1) according to one of claims 1 to 4, - at least one projector (12, 13) which projects visible radiation (14.1, 14.2) onto the composite disk (1). [6] Projection arrangement (100) according to claim 5, comprising a composite disc (1) which has a reflective section (6) which, when viewed through the composite disc (1) from the inner disc (3), is arranged completely within an opaque masking layer (5), wherein the opaque masking layer (5) is arranged in particular in an upper or lower edge region (7.1, 7.2) of the composite disc (1), wherein a projector (12) serves to project visible radiation (14.1) onto the HUD area (H), and a further projector serves to project visible radiation (14.2) onto the reflective section (6).

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