window glass panes

Abstract

The present invention relates to a glazing pane for separating an interior space from an exterior environment, the glazing pane comprising a reflective patch having a sloped profile, a HUD system including said glazing pane, and the use of a sloped profile in the glazing pane.

Description

[Technical Field]

[0001] The present invention relates to a pane of glass for separating an interior space from an exterior environment, the pane of glass comprising a reflective patch having a sloped profile, a HUD system comprising said pane of glass, and the use of a sloped profile in a pane of glass. [Background technology]

[0002] Window panes suitable for reflecting projected images are finding increasing performance and application, at least in transportation applications, particularly when HUD functionality is required.

[0003] The technology of reflective coatings, obtained by depositing metallic and / or dielectric layers by chemical or physical vapor deposition on glass or plastic substrates, provides a variety of reflective performances, e.g., greater than 10% reflection of p-polarized light at Brewster's angle. These coatings can be applied to the surface of window panes or to the interior of window panes, especially laminated panes.

[0004] These coatings are well known to those skilled in the art and offer decisive advantages in terms of quality, processability and performance, with the main drawback being cost.

[0005] Full-surface coating of a windshield corresponds to a large coating area. In certain applications, only a black band display is used as the projection area. In these instances, only a region of the surface of the window pane requires a reflective coating, and therefore, applying a localized coating is more efficient to avoid the reduced yield associated with full-surface coating.

[0006] Topical coatings can also facilitate the implementation of solar control features in transparent areas.

[0007] When only one area of ​​the surface of the pane of glass requires a reflective coating, the deposition of the coating can be selective in that area, or the fully deposited coating can be decoated (removed), a second operation that involves waste of material and process complexity.

[0008] In some instances, coating only in selected areas can result in misalignment between coated and uncoated areas of the pane, especially if there is a difference in light transmission between those areas.

[0009] There is a need to provide a display area that is only a portion of the total surface of the window pane, so that cost drawbacks are reduced, and there is a need to avoid misalignment between coated and uncoated areas of large window panes. Summary of the Invention

[0010] The present invention aims to overcome the above-mentioned drawbacks by providing a pane of glass separating an interior space from an exterior environment, said pane having one interior surface facing the interior space and one exterior surface facing the exterior environment, characterised in that the interior surface is provided in at least one area with a reflective patch having a periphery, the reflective patch having an inclined profile along at least a part of its periphery.

[0011] The reflective patches themselves provide high reflectance of p-polarized radiation, whether projected from a p-polarized source or a mixed source, allowing for a color-neutral display.

[0012] The particular slope profile not only helps to provide effective positioning by covering the edges of the patch, but also helps to reduce edge defects that lead to smearing and / or adhesion problems at the edges of the reflective patch. [Brief explanation of the drawings]

[0013] [Figure 1]FIG. 2 is a schematic diagram of a gradient profile of the present invention.

[0014] [Figure 2] 1 is a schematic diagram of a first embodiment of the present invention;

[0015] [Figure 3] FIG. 2 is a schematic diagram of a second embodiment of the present invention.

[0016] [Figure 4a] FIG. 10 is a schematic side view of a third embodiment of the present invention. [Figure 4b] FIG. 10 is a schematic perspective view of a third embodiment of the present invention.

[0017] [Figure 5a] FIG. 10 is a schematic side view of a fourth embodiment of the present invention. [Figure 5b] FIG. 10 is a schematic perspective view of a fourth embodiment of the present invention.

[0018] [Figure 6a] FIG. 10 is a schematic diagram of a fifth embodiment of the present invention, in top view. [Figure 6b] FIG. 10 is a schematic perspective view of a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] The figures are not drawn to scale.

[0020] Here, the glazing pane of the present invention is used to separate an interior space from the exterior environment. The interior space can be a room or a defined space that needs to be separated from the exterior environment. In a preferred embodiment, the interior space is the interior of a vehicle.

[0021] The inner surface of the pane is therefore the surface that faces the interior space, and the outer surface faces the exterior environment.

[0022] The glazing may be a single sheet of glass or polymer, or may be a laminated sheet of glass and / or polymeric material.

[0023] Examples of glass sheets include float glass sheets, or alternatively, cast or drawn glass sheets, and may be selected from all glass technologies, such as float clear, ultra-clear, or tinted glass, (partially) acid-etched or (partially) sandblasted glass, and combinations thereof. The glass sheets may be of any composition with any optical properties, such as any values ​​of visible light transmittance, ultraviolet transmittance, infrared transmittance, and / or total solar energy transmittance. The glass may be soda-lime silicate glass, aluminosilicate glass, alkali-free glass, borosilicate glass, etc. The glass may typically be clear, tinted, or ultra-clear (i.e., lower Fe content and higher transmittance) glass substrates. Further examples of glass substrates include clear, green, bronze, and blue-green glass substrates.

[0024] Examples of polymeric material sheets include polymethyl methacrylate (PMMA), polycarbonate, polyethylene terephthalate (PET), polyolefin, polyvinyl chloride (PVC), or mixtures thereof.

[0025] Preferred glazing sheets are glass sheets generally useful for providing vehicle glazing.

[0026] The glass may be clear, ultra-clear, or tinted. These glass types are defined by their respective compositions, which may be selected from various types of glass compositions, provided that the invention is not impaired.

[0027] The glass can be annealed glass, tempered glass, or heat-strengthened glass.

[0028] Preferably, the glazing pane, when it is a laminated pane, may comprise at least two sheets of glass and at least one intervening or intermediate layer.

[0029] The interlayer, or intervening layer or laminating material, may be selected from the group consisting of ethylene vinyl acetate (EVA), polyacetals such as polyisobutylene (PIB), polyvinyl butyral (PVB), polyurethanes (PU), polyvinyl chloride (PVC), polyesters, cycloolefin polymers (COP), ionomers, and / or UV-curable adhesives, and others known in the art of glass laminate manufacturing. Blends using any compatible combination of these materials may also be suitable. Preferably, the interlayer comprises a material selected from the group consisting of ethylene vinyl acetate and / or polyvinyl butyral.

[0030] The interlayer acts as a "bonding interlayer" because the interlayer and the glass sheet form a bond that results in adhesion between the glass sheet and the interlayer.

[0031] The interlayers that can be used in the present invention can be transparent or translucent polymer interlayers. However, in certain applications where transparency is not a requirement, the polymer interlayers can be colored or patterned. Colored interlayers can have a light transmittance of 0-85% and can be selected according to the requirements of the area to be used as the projection area in the HUD system.

[0032] Typical thicknesses for the intermediate layer are 0.15 mm to 3.5 mm, preferably 0.30 mm to 1.75 mm, and more preferably 0.5 mm to 1.75 mm. Common commercially available polymer films are polyvinyl butyral (PVB) layers of 0.38 mm, 0.76 mm, 1.52 mm, 2.28 mm, and 3.04 mm. One or more of these films can be used to achieve the required thickness.

[0033] Enhanced sound insulation can be provided by the use of certain interlayers known in the field of laminated glazing.

[0034] The intermediate layer may have an essentially constant thickness, except for surface roughness as is common in the art, or may be a so-called wedge film and therefore have a varying thickness across its surface.

[0035] Considering a laminated glazing comprising two sheets of glass, the first and second sheets may individually have a thickness in the range of 0.2 mm to about 15 mm, alternatively 0.5 mm to about 10 mm, alternatively 0.5 mm to about 8 mm, alternatively 0.5 mm to about 6 mm. Particularly in the automotive field, the first and second sheets may individually have a thickness in the range of 0.2 mm to 6 mm, alternatively 0.4 to 3 mm.

[0036] Both sheets may have the same thickness, for example, 0.5 mm, 0.8 mm, 1.2 mm, 1.6 mm, 1.8 mm, 2.1 mm, or 3 mm. Such a symmetrical arrangement of glass thickness allows for easy processing and conventional sizing of the lamination process.

[0037] The sheets may have different thicknesses, whether in the interior-facing or exterior-facing position, to provide an asymmetric laminated glazing, for example, pane 1 = 0.5 mm and pane 2 = 2.1 mm, pane 1 = 0.8 mm and pane 2 = 2.1 mm, pane 1 = 0.5 mm and pane 2 = 1.6 mm, pane 1 = 0.8 mm and pane 2 = 1.6 mm, or pane 1 = 1.6 mm and pane 2 = 2.1 mm. Such an asymmetrical configuration of glass thickness allows for flexibility in curvature and / or flexibility in weight management and / or flexibility in light / solar control.

[0038] In certain instances it may be suitable to have an asymmetric laminated glazing in which the outer sheet has a greater thickness than the inner sheet (e.g. outer glass sheet=2.1 mm and inner glass sheet=0.5 mm) so as to be able to find a compromise between reduced weight and improved mechanical resistance.

[0039] The reflective patch according to the invention is suitable for reflecting p-polarized radiation at angles of incidence between 40 and 75°, or between 50 and 70°, i.e. in the angular range including Brewster's angle (57°). However, the invention may also be suitable for reflective patches aimed at reflecting mixed reflections (S- and P-polarized) or S-polarized reflections using a suitable projector.

[0040] Such reflective patches are specifically designed to reflect p-polarized radiation, with a view to reflecting projected images in HUD systems.

[0041] Typically, a transparent glass plate has a reflectivity for p-polarized light (Rppol) of 1% at an angle of 65°, a reflectivity for p-polarized light (Rppol) of 0% at an angle of 57° (Brewster), and a reflectivity for s-polarized light (Rspol) of 35% at an angle of 65°.

[0042] Preferred reflective patches typically have a reflectivity of 18% or greater, preferably 20% or greater, for p-polarized light at Brewster's angle.

[0043] A suitable preferred reflective patch may have a reflectivity for p-polarized light at a 65° angle (Rppol) of 26% and a reflectivity for s-polarized light at a 65° angle (Rspol)=40%.

[0044] The reflective patches are preferably provided within a defined area on the inner surface of the glazing pane, said defined area being defined according to the possible display area that may be aimed by a projector of a HUD that may be used. Thus, the defined area may be, for example, 2 cm 2 , alternatively 4cm 2 , alternatively 8cm 2 , alternatively 10cm 2 The defined area may have any surface area dimension from 4 m 2 Up to 2.5m as an alternative 2 Up to 1m as an alternative 2 Up to 0.5m as an alternative 2 Up to 0.3m as an alternative 2 It can be up to.

[0045] The area of ​​the window pane to which the reflective patch may be attached may have any value of light transmittance, with TL typically measured according to ISO 9050 using Illuminant A at an observer aperture slit angle of 2° (=Ill.A, 2°).

[0046] The periphery of the reflective patch may have n edges (n≧1) and may define a circle, an ellipse, a triangle, a square, a rectangle, a trapezoid, or any other suitable shape.

[0047] An example of a reflective patch is a coated patch having a reflective coating suitable for reflecting p-polarized light. The reflective coating can be positioned on a first surface of the patch facing the inner surface of the window pane or on a second surface of the patch facing the interior space. Indeed, some reflective coatings, such as those containing a functional silver layer, require protection from ambient conditions, while other coatings can withstand ambient conditions.

[0048] Examples of such reflective coatings suitable for reflecting p-polarized light include: a reflective coating comprising at least one high refractive index layer having a thickness of 50 to 100 nm and at least one low refractive index layer having a thickness of 70 to 160 nm, wherein the at least one high refractive index layer comprises at least one of oxides of Zr, Nb, Sn, mixed oxides of Ti, Zr, Nb, Si, Sb, Sn, Zn, In, nitrides of Si, Zr, and mixed nitrides of Si, Zr; or, optionally, starting from the substrate surface, sequentially: 1) a first coating consisting of one or more high refractive index layers, the first coating having a thickness of 1 to 100 nm; 2) a second coating consisting of one or more low refractive index layers, the second coating having a thickness of 1 to 220 nm; 3) a third coating consisting of one or more high refractive index layers, the third coating having a thickness of 40 to 150 nm; and 4) a fourth coating consisting of one or more low refractive index layers, the fourth coating having a thickness of 40 to 220 nm. 5) a reflective coating further comprising at least one first absorbing material layer, the at least one first absorbing material layer having a thickness of 0.2 to 15 nm, the absorbing material having an average refractive index n greater than 1 and an average extinction coefficient k greater than 0.1, the average n and k being calculated over values ​​at wavelengths of 450 nm, 550 nm, and 650 nm; or a reflective coating comprising only one conductive layer and, above and below the conductive layer, a dielectric layer sequence consisting of n optically low refractive index layers having a refractive index less than 1.8 and (n+1) optically high refractive index layers having a refractive index greater than 1.8, alternating therebetween, where n is an integer equal to or greater than 1; or a reflective coating comprising four silver-based or silver functional metal layers and five dielectric coatings, each functional metal layer being disposed between two dielectric coatings.

[0049] Preferred coatings are those that do not contain a functional silver layer, as this requires less protection against oxidation.

[0050] Such coatings are deposited on the patches using typical deposition techniques, including PVD or CVD, and have the advantage that they are easily applied to glass substrates and can withstand exposure to interior spaces.

[0051] The patch itself may be made from any of the materials mentioned above for the glazing, ie glass and / or polymeric materials.

[0052] Examples of glass patches include float glass, or alternatively, cast or drawn glass, and can be selected from all glass technologies, such as float clear, ultra-clear, or tinted glass, (partially) acid-etched or (partially) sandblasted glass, and combinations thereof. The glass patches can be of any composition with any optical properties, such as any values ​​of visible light transmittance, ultraviolet transmittance, infrared transmittance, and / or total solar energy transmittance. The glass can be soda-lime silicate glass, aluminosilicate glass, alkali-free glass, borosilicate glass, etc. The glass can typically be clear, tinted, or ultra-clear (i.e., lower Fe content and higher transmittance) glass substrate. Further examples of glass substrates include clear, green, bronze, and blue-green glass substrates.

[0053] Examples of polymeric material sheets include polymethyl methacrylate (PMMA), polycarbonate, polyethylene terephthalate (PET), polyolefin, polyvinyl chloride (PVC), or mixtures thereof.

[0054] The patch is preferably a float glass patch having a thickness of 3 mm or less, preferably 2.5 mm or less, more preferably 1.8 mm or less, with thin patches having a thickness of 1.2 mm or less being most preferred as they are easier to fix to the window pane.

[0055] Other examples include patches containing reflective films suitable for reflecting p-polarized light, including films containing at least one transparent liquid crystal layer, films containing at least one cholesteric liquid crystal layer, and films containing multiple alternating polymer interference layers.

[0056] For example, a reflective film including a liquid crystal layer may be bonded as a functional foil to a surface of the patch, i.e., either the first surface of the patch facing the inner surface of the window pane or the second surface of the patch facing the interior of the compartment.

[0057] The corresponding liquid crystal layer can be applied as a coating to a carrier foil made of, for example, cellulose triacetate (TAC), polyethylene terephthalate (PET), polyethylene (PE), polyamide (PA), or other conventional polymer materials. High-precision coating processes for producing such functional liquid crystal films are available and known in the art, and functional films are commercially available.

[0058] Such layers are known and are also called p-polarized reflective films. If other light / radiation is reflected, the film can be selected appropriately for s-polarized or mixed polarization.

[0059] Commercially available examples of such reflective films include Windshield Combiner Film available from 3M under the trade name 3M® WCF-PVB, reflective film available from Toray Industries, Inc. under the trade name PICASUS® VT, or reflective film available from Fujifilm under the trade name Wavista®.

[0060] To provide a reflective patch, a reflective film may be applied to the patch using any known adhesive means, such as an optically clear resin.

[0061] Suitable optically transparent resins have a refractive index of about 1.4 to 1.6, and examples of such resins include acrylic resins, methacrylate resins, urethane resins, silicone resins, polyester resins, epoxy resins, and polysulfide resins.

[0062] Such optically transparent resins include, for example, thermosetting, highly extensible silicone gels. The optically transparent resins preferably cure at low temperatures below 70°C for 25 to 30 minutes to become soft, tacky gels. The optically transparent resins may be pressure-sensitive adhesives or any curable resins.

[0063] The application of such optically clear resins is well known in the art.

[0064] The transparency of the optically transparent resin is greater than 90%, preferably greater than 95%, and more preferably greater than 99%, so that the transmittance of the window pane can be maintained if necessary.

[0065] The reflective patch is preferably attached to the front surface of the window pane facing the interior space.

[0066] The reflective patch may be fixed to the window pane during an autoclave step. Autoclave is a well-known technique commonly used for automobile window panes. An interlayer (PVB, EVA, etc.) may be used between the coated patch and the window pane. If the window pane is a laminated window pane, the coated patch may be attached simultaneously with the lamination step or may be positioned after said lamination step. This method is advantageous because it can be easily implemented in a single step. This method also makes it possible to fix a reflective patch having the same curvature as the window pane (if there is a curvature).

[0067] The reflective patch can also be fixed to the window pane using the aforementioned adhesive means that rely on optically transparent resins, which has the advantage that the patch can be easily positioned on the window pane and can be carried out after the window pane is assembled.

[0068] When the surface of the reflective patch is not parallel to the surface of the pane to which it is adhered, the thickness of the adhesive means may vary along the width of the surface of the reflective patch. Indeed, in some instances, the first surface of the patch facing the inner surface of the pane, i.e., the surface used for adhesion to the pane surface, has a different curvature (if any) than the pane surface. The first surface of the reflective patch may be more or less curved than the pane, and such curvature of the reflective patch is independent of the possible curvature of the pane.

[0069] The reflective patch may have a light transmittance of 60% or more, or even 70% or more when it is required to be applied in a transparent area of ​​a window glass sheet that may be used as a vehicle windshield. However, the advantage of the technical solution according to the present invention is that when the reflective patch is applied to a hidden area of ​​a window glass sheet having a TL of 30% or less, the reflective patch can have any light transmittance between 0 and 92%.

[0070] In a first example, at least one area provided with a reflective patch may have an initial light transmittance of 60% or more (Ill. A, 2°). That is, the reflective patch may be attached to a transparent area of ​​the window pane, i.e., an area of ​​the window pane that has a TL of 60% or more, preferably 70% or more, before the reflective patch is attached. This has the advantage that the display area may be within the view of the observer toward which the projected information is directed. The advantage is that the observer then sees the projected image within an area that overlaps with the field of view through the window pane. Therefore, in such a first example, the reflective patch, especially when positioned in an area of ​​the window pane that has a TL of 60% or more, may preferably have a high transmittance within the visible spectrum, allowing for a color-neutral display.

[0071] In the field of automobiles, especially windshields, the standard ECE-R43 stipulates the technical requirement that the central field of view of the automobile must have a high light transmittance (typically more than 70%). Therefore, in such a first instance, the reflective patch must meet the transparency conditions of the standard ECE-R43.

[0072] In a second example, at least one area provided with a reflective patch may have an initial light transmittance of 30% or less (Ill. A, 2°). That is, the reflective patch may be applied to a non-transparent area of ​​the window pane, i.e., an area of ​​the window pane that has a TL of 30% or less, preferably 15% or less, before the reflective patch is applied. In these examples, an advantage is that the projected image is outside the viewer's field of view. In this case, the quality and color of the reflective patch can be adapted, and fewer technical and chemical constraints are required regarding transparency and color neutrality. On the other hand, in this case, the reflective patch is also invisible or inconspicuous from the outside of the window pane. Furthermore, the reflectance of an image from an area with a darker background is typically brighter. A further advantage is that the reflective patch is protected from direct sunlight, and the risk of damage or scratches is reduced because the shading area is generally located at the periphery of the window pane and is difficult for the driver or vehicle occupants to reach.

[0073] Examples of opacifying means that provide a glazing sheet with a TL of 30% or less include dark print, dark inserts, dark patches, or combinations thereof.

[0074] Dark printing includes enamel and paint applied by screen printing or typical methods for depositing enamel and paint. Dark inserts include a tinted interlayer inserted within an interlayer used to provide a laminated glazing or between the first surface of the reflective patch and the inner surface of the glazing, which may serve as an adhesive during an autoclave step, etc. A dark patch may be incorporated within the reflective patch when the patch material (glass or polymer) is selected to have a TL of 30% or less.

[0075] The reflective patch may also overlap both an area of ​​the pane having a TL of 60% or more and an area of ​​the pane having a TL of 30% or less, bridging the areas of the pane having two different light transmittances.

[0076] In either the first or second example, alone or in combination, the inclined profile according to the invention has the advantage of smoothing the edges of the periphery of the reflective patch, so that the inside of the pane does not have the objectionable appearance of the reflective patch and that dust does not accumulate on the edges of the reflective patch, and furthermore, the reflective patch cannot be easily removed by mechanical action (such as scratching) or by cleaning action.

[0077] The sloped profile is provided along a portion of at least one edge of the periphery of the reflective patch. The sloped profile can be used to hide thickness variations between the window pane and the reflective patch. In some embodiments, the sloped profile is provided over an upper portion of at least one edge of the periphery of the reflective patch or on a portion of the upper edge of the periphery of the reflective patch.

[0078] Thus, a sloped profile can be used to ensure a contact offset between a first region and a second region, especially when there is a different light transmittance in the coated and uncoated regions.

[0079] Typically, the panes of glass may be inserted into the frame by a fastening means such as a sealant to attach the panes to the interior space.

[0080] In some embodiments, at least a first portion of the outer periphery is visible from an interior perspective, while a second portion may be hidden within the vehicle body or within the side of the window pane within the fastening element (as shown by FIG. 4).

[0081] In other embodiments, the sloped profile may be part of a dashboard that is designed to include an opening with a reflective patch affixed to the window pane, thereby allowing projection onto selected areas of the windshield. In some examples, no part of the perimeter is substantially visible from an interior perspective, hidden within a dashboard design that covers the perimeter (as shown by FIG. 5).

[0082] In some other embodiments, the reflective patch has a beveled profile along the entire perimeter edge, with the final aesthetics and positioning determining which portions of the perimeter are given the beveled profile.

[0083] As depicted in FIG. 1, the slope profile includes at least one notch having a thickness (t) corresponding to the thickness of the reflective patch.

[0084] The slope profile can be designed according to the thickness of the adhesive means and the thickness of the reflective patch. As discussed above, when the surface of the reflective patch is not parallel to the surface of the window pane to which it is adhered, the thickness of the adhesive means may vary along the width of the surface of the reflective patch. In these cases, the slope profile is designed so that its thickness includes the thickness of the adhesive means and the thickness of the reflective patch.

[0085] The gradient profile shown in FIG. 1 further has a width (w) and height (h) independently within the range of 0.4 to 30.0 mm, alternatively 1.0 to 20.0 mm.

[0086] 1 illustrates a sloped profile with a circular (semicircular) cross section, but technically any other cross section that best suits the design and technical requirements can be presented. There are various options for protruding or smooth designs, provided that the sloped profile serves to hide part of at least one edge of the periphery of the reflective patch.

[0087] This is true even if the thickness of the adhesive means varies along the width of the surface of the reflective patch, provided that the sloped profile serves to hide part of at least one edge of the periphery of the reflective patch.

[0088] The gradient profile can be made of a polymer, preferably a thermoplastic polymer or a thermoplastic elastomer, and processed by, for example, extrusion or injection molding. Both methods allow the production of continuous uniform shapes to fit the required design. The gradient profile can be clear, transparent, or colored, as is typically accepted for these types of materials, and can be best suited to the light transmittance of the background area to which it is fixed.

[0089] Examples of such materials include polyethylene terephthalate (PET), polyurethane resin, polyethylene, polypropylene, polystyrene, polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), thermoplastic elastomers (TPE), polyisobutylene, silicone, acrylic resin, cyanoacrylate, epoxy resin, polyamide, ethylene vinyl acetate, polysulfide, butyl rubber, ethylene-propylene copolymer, styrene-butadiene rubber, and mixtures or combinations thereof. These materials can be biologically derived (bio-based), recycled, or chemically derived.

[0090] Thus, in some instances, the beveled profile may be an optically clear resin, particularly if the beveled profile is not visible or noticeable to the occupants, which has the advantage of not interfering too much with vision and being aesthetically pleasing on the surface of the glazing.

[0091] In other instances where the sloped profile is an element of the dashboard, the sloped profile may be the same color and material as said dashboard and therefore may be tinted and opaque (such as a typical AVO material), which has the advantage that as an element of the interior design the element is both structurally pleasing and aesthetically pleasing to look at.

[0092] The sloped profile may be self-adhesive or may be affixed to the window pane by a separate adhesive or primer. The adhesive may be clear if required by the design.

[0093] Examples of adhesives include cyanoacrylates, epoxy resins, silicone adhesives, and mixtures or combinations thereof, which have the advantages of transparency, heat resistance, waterproofness, and high strength.

[0094] Thus, the gradient profile may be opaque, colored, or transparent or translucent.

[0095] The glazing pane according to the present invention may further comprise an IR-reflective coating. In such an example compatible with the present invention, the glazing pane is a laminated glazing pane comprising two glass sheets and at least one interlayer. The IR-reflective coating may be present between the two glass sheets, i.e., on the surface of at least one of the glass sheets (in which case it may be provided by chemical or physical vapor deposition on the glass sheet surface, known as P2 or P3), or it may be present within an interlayer bonding the two glass sheets together, such as a PET-based solar control window film with an infrared-absorbing or reflective ceramic coating. Such IR-reflective coatings are well known in the art for providing solar control and / or heating functions to glazing panes.

[0096] In some examples, the IR reflective coating may be removed due to the use of optical systems other than the HUD projector according to the present invention, such as IR cameras or LIDARS.

[0097] To avoid double images from the IR reflective coating, it may be useful to avoid overlapping of the IR reflective coating with the reflective patch for the head-up display.

[0098] Specifically, the pane may be provided with an IR-reflective coating in areas of the pane having a TL greater than 70% and with a reflective patch in areas of the pane having a TL of 30% or less. In this way, the TTS (total solar transmittance) may be optimized at a value less than 60%, alternatively less than 55%, without impairing the function of the reflective patch for polarized light as discussed above. In such an example, the edges of the IR-reflective coating may be hidden by the sloped profile, thus avoiding a visible aesthetic change between areas with the IR-reflective coating and areas without the IR-reflective coating (which may be decoated).

[0099] Laminated glass panes can be manufactured by methods known per se. Typically, the outer glass pane, the inner glass pane, and the intervening layers are stacked flat on top of each other. The surface of the outer glass pane facing the interlayer or the surface of the inner glass pane facing the interlayer can be fully or partially coated with an IR-reflective coating, as discussed above. In some examples, the IR-reflective coating is present in the interlayer. A reflective patch can be positioned and disposed on the surface of the inner glass pane opposite the interlayer facing the interior of the vehicle (referred to as surface P4 in laminated glazing).

[0100] The outer and inner glass panes are laminated together via the interlayer, for example, by an autoclave process, a vacuum bag process, a vacuum ring process, a calendar process, a vacuum laminator, or a combination thereof. The outer and inner glass panes are typically joined under the influence of heat, vacuum, and / or pressure.

[0101] The glazing panes according to the invention may be used as windshields, roofs, cockpits, sidelights, backlights, among other vehicle applications, or for architectural applications, such as curtain walls, windows, doors, shop displays, refrigerator doors, etc.

[0102] The vehicle may include a land vehicle, a sea vehicle, an air vehicle, or a space vehicle.

[0103] The present invention also relates to a HUD system comprising a window pane as described herein and at least one projector that emits radiation, wherein the area of ​​the inner pane provided with the reflective patches is a display area for an image projected by the at least one projector.

[0104] In such HUD systems, a projector is aimed at the HUD area and the projected image is reflected into the display area. Thus, the projector illuminates an area of ​​the windshield and the radiation is reflected back toward the observer (driver), creating an image or virtual image that appears behind the windshield when the observer looks from the inside (perspective view). The area of ​​the windshield that can be illuminated by the projector is sometimes referred to as the HUD area.

[0105] Such projectors are typically known in the art and will not be described here.

[0106] Typically, current HUD projectors operate primarily with s-polarized radiation, illuminating the windshield at an angle of incidence of approximately 65°. A problem arises in that the projector image is reflected from both outer surfaces of the windshield (referred to as air / glass interfaces P1 and P4). As a result, in addition to the desired main image, a slightly offset secondary image, known as a ghost image ("ghost"), also appears. Various measures, such as a wedge interlayer, can be used to mitigate this problem. Another measure to mitigate this problem is to reduce the transmitted radiation to the outer glass sheet by having the HUD area have a TL of less than 30%.

[0107] Within the scope of the present invention, the radiation beam from the projector may be 20-100% p-polarized, whereby the image formed by the projection beam of the HUD projector may be composed of mixed polarizations, with the percentage of p-polarized light being at least 20%, preferably at least 50%, more preferably at least 75%, even more preferably at least 90%, and most preferably 100%.

[0108] As a result, the radiation provided by the projector can be advantageously reflected by the reflective patch, especially when the TL of the HUD area is 70% or greater. When the HUD area is within an area of ​​a window pane with a TL of less than 30%, the proportion of light that is not p-polarized is less important because the projected image is not transmitted or reflected by the external air-glass surface. One additional advantage of operating with a p-polarized beam is the compatibility of the image or virtual image with polarized sunglasses.

[0109] Radiation from the projector is directed at a display area provided with reflective patches at an angle of incidence of 50 to 75°.

[0110] Finally, the present invention relates to the use of a sloped profile for securely fixing at least a portion of the periphery of a reflective patch affixed to the inner surface of a window pane separating an interior space from the exterior environment, said window pane having one inner surface facing the interior space and one outer surface facing the exterior environment, said sloped profile being positioned along at least a portion of the periphery of the reflective patch.

[0111] The present invention is exemplified by the following mutually compatible embodiments.

[0112] Figure 2 shows a cross section (side view) of a window glass pane (201) including an inner surface (202) and a four-edge reflective patch (203) attached to the inner surface. The reflective patch has four edges: a bottom edge (203L), a top edge (203U), and right and left edges (not shown). The area of ​​the window glass pane (201) provided with the reflective patch (203) in Figure 2 has a TL of 70% or greater. A sloped profile (204L) is attached to the bottom edge (203L), and a sloped profile (204U) is attached to the top edge (203U). The right and left edges (not shown) may also each have a sloped profile.

[0113] 3 shows a cross section (side view) of a window glass pane (301) similar to FIG. 2, including an inner surface (302) and reflective patches (303) that are provided in defined areas of the window glass pane (301) that have a TL of 30% or less. The areas are provided with a shielding means (305), such as enamel or paint, as discussed above. The areas may be black band areas or any shielded areas of the window glass pane. A beveled profile (304L) is applied to the lower edge (303L), and a beveled profile (304U) is applied to the upper edge (303U). There may also be beveled profiles on the right and left edges (not shown).

[0114] FIG. 4 shows a cross section (side view) of a laminated glazing pane (401), which is composed of two glass sheets (411 and 412) and an interlayer (413), and has an inner surface (402). Contact between the elements is suggested, though not shown for clarity. Again, a reflective patch (403) is provided in a defined area of ​​the occlusion region of the glazing pane (401) having a TL of 30% or less. An occlusion means (405), such as enamel or paint or a dark interlayer, as discussed above, is provided in this region, here at position 2 of the laminated glazing pane. The reflective patch has four edges: a bottom edge (403L), a top edge (403U), and right and left edges (not shown). A sloped profile (404U) is applied to the upper edge (403U), and the body (405) conceals and covers the lower edge (403L). The sloped profile may be applied to each section of the left and right edges that is not concealed by the body (not shown). In this particular case, the IR-reflective coating (414) may be applied within the intermediate layer (413) or deposited on one of the surfaces of the sheets (411) and (412) facing the intermediate layer. It may also be appropriate, as shown, for the IR-reflective coating (414) not to overlap the reflective patch (403), with the lower edge of the IR-reflective coating (414) being concealed by the sloped profile.

[0115] 4b shows a front projection view of a window pane including a reflective patch (403) in the line of sight of the shielding strip (405) from the perspective of a vehicle occupant (see-through perspective). The reflective patch is attached and positioned on the window pane (501) so that it can project and reflect in the shielding strip area of ​​the windshield. The lower portion of the periphery of the reflective patch is hidden by the vehicle body (405), but the upper edge is provided with a sloped profile of a transparent thermoplastic material that allows the line of sight, so that only the exterior of the shielding strip is visible to the vehicle occupant (404U is preferably transparent).

[0116] FIG. 5a shows a cross section (side view) of a laminated pane (501), which is composed of two glass sheets (511 and 512) and an interlayer (513) and has an inner surface (502). Contact between the elements is implied, though not shown for clarity. Again, a reflective patch (503) is provided in a defined area of ​​the occlusion region of the pane (501) having a total thickness (TL) of 30% or less. A occlusion means (505), such as enamel or paint or a dark interlayer, as discussed above, is provided in this region, here at position 2 of the laminated pane. The reflective patch material may also be dark and / or tinted, and have a total thickness (TL) of 30% or less. The reflective patch has four edges: a lower edge (503L), an upper edge (503U), and right and left edges (not shown). The sloped profiles (506U and 506L) are applied along all edges of the periphery of the reflective patch in the form of a part of the dashboard. The IR-reflective coating (514) may be applied in the intermediate layer (513) or may be deposited on one of the surfaces of the sheets (511) and (512) facing the intermediate layer. It may also be appropriate, as shown, for the IR-reflective coating (514) not to overlap the reflective patch (503), but for the lower edge of the IR-reflective coating (514) to be hidden by the sloped profiles designed into the dashboard structure.

[0117] Figure 5b shows a front projection view of a window pane where the dashboard is designed to include an opening containing a reflective patch (503) in the line of sight of the shielding strip (505) from the passenger's perspective (see-through perspective). The reflective patch is affixed to and positioned on the window pane (501) so that projections and reflections can occur in the shielding strip area of ​​the windshield. The entire periphery of the reflective patch is hidden within the dashboard design that covers the periphery, so that it is substantially hidden from the view from inside.

[0118] Figure 6a shows a cross section (top view) of a window pane (601) including an inner surface (602) and a reflective patch (603) with a periphery (not shown). The reflective patch (603) is adhered to the inner surface (602) by an adhesive means (610) having a varying thickness along the width of the reflective patch (603). A sloped profile is present in Figure 6b but not designed into Figure 6a.

[0119] Figure 6b shows a front projection view of a window pane (601) including a reflective patch (603) adhered to its inner surface by adhesive means (610), not shown. A sloped profile (604) is provided along the periphery of the reflective patch (603). The reflective patch of Figure 6 can be applied to any area of ​​the window pane, regardless of the light transmittance of that area, as discussed in other embodiments of the present invention.

Claims

1. 1. A window glass pane separating an interior space from an exterior environment, the window glass pane having one interior surface facing the interior space and one exterior surface facing the exterior environment, the interior surface being provided in at least one region with a reflective patch having a periphery, the reflective patch having an inclined profile along at least a part of its periphery.

2. 10. The glazing pane of claim 1, wherein the reflective patch is a coated patch having a reflective coating adapted to reflect p-polarized light, or the reflective patch comprises a reflective film adapted to reflect p-polarized light selected from a film comprising at least one transparent liquid crystal layer, a film comprising at least one cholesteric liquid crystal layer, and a film comprising a plurality of alternating polymer interference layers.

3. 3. A glazing pane according to claim 1 or 2, wherein the gradient profile is selected from polyethylene terephthalate (PET), polyurethane resin, polyethylene, polypropylene, polystyrene, polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), thermoplastic elastomer (TPE), polyisobutylene, silicone, acrylic resin, cyanoacrylate, epoxy resin, polyamide, ethylene vinyl acetate, polysulfide, butyl rubber, ethylene-propylene copolymer, styrene-butadiene rubber, and mixtures or combinations thereof.

4. A glazing according to any one of claims 1 to 3, wherein the glazing is selected from a single sheet of glass or polymer, or may be a laminated glazing of glass and / or polymer material.

5. 5. The glazing pane of claim 4, wherein the glazing pane comprises at least two sheets of glass and at least one interlayer.

6. A glazing pane according to any one of claims 1 to 5, further comprising an IR-reflective coating.

7. 7. A pane according to any one of the preceding claims, wherein the at least one area provided with a reflective patch has a light transmission (11. A, 2°) of 60% or more.

8. 7. A pane according to any one of the preceding claims, wherein the at least one area provided with a reflective patch has a light transmission (11. A, 2°) of less than or equal to 30%.

9. 9. The glazing pane of claim 8, wherein the areas having a TL of 30% or less are provided with an opacifying means comprising dark print, dark inserts, dark patches, or combinations thereof.

10. 10. A HUD system comprising a window pane according to any one of claims 1 to 9 and at least one projector that emits radiation, wherein an area of ​​the window pane provided with the reflective patches is a display area for an image projected by the at least one projector.

11. 11. The HUD system of claim 10, wherein the radiation emitted from the projector is 50-100% p-polarized.

12. 12. The HUD system of claim 10 or 11, wherein the radiation emitted from the projector strikes the display area provided with the reflective patches at an angle of incidence between 40° and 75°.

13. 10. Use of a sloped profile on a window glass pane according to any one of claims 1 to 9 for securely fixing at least a part of the periphery of a reflective patch affixed to an inner surface of the window glass pane separating an interior space from an external environment, the window glass pane having one inner surface facing the interior space and one outer surface facing the external environment, the sloped profile being positioned along at least a part of the periphery of the reflective patch.

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