Vehicle glazing assembly with light scattering print

Abstract

The invention relates to a vehicle glazing assembly (3) having a light-conducting glazing panel (8) having a printed portion (11), having a light coupling-in of light of an illumination device (4) into the glazing panel (8) via an edge region (5) of the glazing panel (8), and having a light coupling-out of the coupled-in light from the glazing panel (8) by means of the printed portion (11) of the glazing panel (8), wherein the printed portion (11) is formed as a light-scattering structure from an ink printed on the glazing panel (8). A polymer cover layer (10) covers the light-scattering structure. The vehicle glazing assembly has a low-emissivity coating (19) of the glazing panel (8). According to the invention, the refractive index n G of the glazing panel (8), the refractive index n P of the printed portion (11) and the refractive index n D of the cover layer (10) are in the following relationship: n G ≥ n D and n P ≥ n D .

Description

Technical Field

[0001] The present invention relates to a vehicle glass assembly having a light guide glass plate with a printed portion, having light coupling (Lichteinkopplung) that couples light from an illumination device into the glass plate via an edge region of the glass plate, and light coupling (Lichtauskopplung) that couples the coupled light out of the glass plate by means of the printed portion of the glass plate, wherein the printed portion is formed as a light scattering structure by ink (Tinte) printed on the glass plate, and wherein a polymer coating layer covers the cured ink and has a Low-E coating on the glass plate. Background Technology

[0002] A vehicle glass assembly having a light guide glass plate with a printed portion is known from EP 3 702 217 A1. The printing is performed using individual ink droplets spaced apart from each other, allowing observation through the printed glass plate. However, such a printed portion may cause optical distortion for an observer viewing a scene through the printed glass plate due to the lensing effect of the printed structure. Such optical distortion may occur, for example, due to the different refractive indices of the printed portion and the polymer coating. Summary of the Invention

[0003] To reduce heat radiation emanating from the vehicle, a low-emissivity (Low-E) coating is applied to the inner side of the window panel facing the vehicle's interior. The Low-E coating on the glass panel causes a lateral color shift in the light reflected by total internal reflection in the light guide glass due to the non-color-neutral internal reflection at the interface between the light guide glass and the Low-E coating. Therefore, for example, a significant attenuation of the red light component causes the white light coupled into the glass panel to appear increasingly bluish-green.

[0004] The objective of this invention is to provide a vehicle glass assembly as described at the outset, which improves upon its optical properties.

[0005] This task is solved according to the invention in the vehicle glass assembly described at the beginning by the following method: the refractive index n of the glass plate G The refractive index n of the printing section P and the refractive index n of the coating layer D At n G ≥ n D And n P ≥ n D The relationship.

[0006] Advantageous configurations of the invention are given in the dependent claims.

[0007] The color shift of total internally reflected light in the light guide glass plate is so related to the reflection angle that the portion of light reflected at a flatter angle in the glass plate exhibits a stronger color shift. This is achieved by establishing the refractive index n according to the present invention. G n P and n D Relationship n G ≥ n P >n D This achieves the goal that the portion of light reflected at a flatter angle in the glass plate, which exhibits stronger color shift, is not coupled into the printed light-scattering structure formed by ink droplets. Thus, color shift is at least reduced. Optical distortion can therefore also be reduced or largely avoided for the observer.

[0008] In one implementation, it is set that for n G and n P Relationship applicable to: n P ≥ n G Using this relationship, the intensity of the light coupling is optimized and even maximized, because for the light guide glass plate, as the refractive index n increases... P Relative to refractive index n G As the volume increases, more light is coupled into the printing section and then coupled out through the printing section.

[0009] Typically, when using conventional transparent soda-lime silicate glass, a color shift towards green occurs due to absorption at the iron oxide sites. This color shift can be largely eliminated by using iron-poor (low-iron) glass, for example, when using glass with a low iron oxide content (<0.05% and especially <0.02%).

[0010] In one implementation, the refractive index value in the visible light range, for example, for light at 589.33 nm, is: n G >= 1.5, especially in the range of 1.5 to 1.58; n D <= 1.49, and especially in the range of 1.48 to 1.49; and n P >1.48, and particularly in the range of 1.48 to 1.9, preferably in the range of 1.48 to 1.7; and particularly n G = 1.51 to 1.52, n D = 1.48 to 1.49 and n P = 1.51 to 1.53.

[0011] Preferred refractive index (for wavelength 589.33 nm) is, for example, for glass material nG = 1.505, for PVB (polyvinyl butyral) used as a covering layer. D = 1.482. The refractive index of the light scattering structure is preferably in the range of n. P = Set within the range of 1.482 to 1.505.

[0012] In a glass plate, light is guided at a flat angle toward the interface. The critical angle α for total internal reflection is less than the incident angle (measured relative to the interface). D = 90°-arcsin(n D / n G The light is totally internally reflected and guided, while light with a larger angle penetrates into the coating layer, is absorbed in the coating layer, and is no longer guided within the glass. Therefore, the critical angle is the angle between the interface and the angle of incidence of the light. Here, the flat angle of light is understood to be an angle sufficient to produce the effect of total internal reflection and therefore less than or equal to the critical angle of internal total internal reflection.

[0013] The overlay is made of thermoplastic materials, such as PVB (polyvinyl butyral), TPU (thermoplastic polyurethane), or EVA (ethylene-vinyl acetate), and the overlay is preferably dark in color.

[0014] A preferred refractive index (for a wavelength of 589.33 nm) is, for example, n G = 1.505, for PVB n as the overlay D = 1.482. The refractive index of the light scattering structure is preferably in the range of n. P = in the range of 1.482 to 1.505.

[0015] For the critical angle of total internal reflection (measured relative to the interface) at the interface between the glass plate and the printed structure, α is applicable. D =90°-arcsin(n D / n G It has an angle greater than α. D Light enters the printed structure within the area of ​​the glass plate covered by the printed structure. The penetration fraction of the light guided within the glass plate is therefore 1 - (α) / (α). P / α D ). In a given n D and n G In this case, the intensity of the scattered light is determined by the refractive index of the printed structure.

[0016] The printed structure relates to a structure applied to the surface of a glass plate. This structure can be applied directly or indirectly to the surface of the glass plate. In the case of direct application, the structure is applied to the surface of the glass plate particularly through a printing process. In this process, structural elements in the form of ink are arranged on the surface of the glass plate such that these structural elements, in particular, form structures that scatter, refract, and / or diffract light. Preferably, in the case of direct application, ink droplets are applied to the surface of the glass plate. The ink droplets can be in a solid or liquid state. In the case of indirect application, the structural elements are applied to a carrier material. Here, these structural elements are preferably formed in a manner similar to the structural elements previously described in the case of direct application. The carrier material is arranged on the surface of the glass plate, wherein the structural elements applied to the carrier material are arranged on the surface of the glass plate. In one configuration, the carrier material is removed. Structures directly applied to the surface of the glass plate and / or structures applied to the carrier material are manufactured, for example, by means of preferably digital printing (such as laser printing or inkjet printing), gravure printing, and / or screen printing.

[0017] Printed structures with a circular (abgerundet) surface (which does not extend parallel to the surface of the glass) will produce distortion when viewed through perspective.

[0018] The distortion of the printed structure (or ink droplet) (which can be described, for example, by a plano-convex lens using the local radius of curvature R) can be estimated using the grinding lens formula (Linsenschleiferformel): D = 1 / f = (n P / n D ) / R, Here, R, as the local radius of curvature, is the local radius of the interface of the printed structure (or ink droplet) relative to the cover layer.

[0019] When the refractive index n P At refractive index n G and refractive index n D As the refractive index n decreases within a certain range, the distortion or refractive power decreases linearly, while the intensity of light scattering decreases more strongly than linearly. Reducing the intensity to, for example, about 50% only results in about a 25% improvement in refractive power (Brechkraft-Verbesserung). Therefore, the refractive index n of the printed structure is set by balancing the desired intensity with tolerable optical distortion. P .

[0020] According to a preferred embodiment, the material of the printed structure is selected such that the refractive index n of the printed structure is... P At n P >(n G + n DWithin the range of ) / 2. Therefore, the intensity of light scattering by the scattering particles introduced into the printed structure is optimized.

[0021] In another preferred embodiment, the refractive index n of the light scattering structure is... P Having n P <(n G + n D The value of ) / 2 is thus optimized so that only a small amount of distortion is observable.

[0022] According to a preferred embodiment, the ink contains scattering particles that determine the refractive index n of the printed portion, light-scattering structure, or ink droplet. P Furthermore, the refractive index can be advantageously set by the proportion of scattering particles in the ink. Here, the volume fraction of the scattering particles and / or the material of the scattering particles are the refractive index n to be set for the printing section, ink droplets, or light scattering structure. P The volume fraction of the scattering particles in the ink is selected based on the amount of particles. For example, 5% to 50% is acceptable. A volume fraction of 30% to 40% TiO2 particles has proven to be advantageous.

[0023] Transparent inks, for example, consist of UV-curable acrylic resin along with particles composed of oxides or nitrides (such as TiO2 or Al2O3) distributed within it. Common products, for example, contain 2-phenoxyethyl acrylate or isobornyl acrylate as a base.

[0024] Since acrylic resins typically have poor adhesion to PVB in the coating layer, it can be advantageous to incorporate adhesion promoters into the resin to improve adhesion to PVB.

[0025] Printed structures can consist of a large number of individual, especially small, discrete ink droplets, which are indistinguishable to the eye and are particularly spaced apart from each other.

[0026] Preferably, the ink droplets are printed in the form of lenses or hemispherical shapes. The ink has a viscosity such that when applied to a glass plate (especially in digital printing methods), it forms droplets of such a shape on the glass plate. The shape of the hemispherical is also determined by the velocity of the ink upon impact with the glass plate and the curing speed of the ink or droplets as they dry. These parameters are defined such that the droplets have the desired shape after drying and curing. The hemispherical has a diameter and a height of its base, which are in a ratio of, for example, 0.5 to 1.5. The flank angle of the droplet (defined as the angle between a perpendicular line from the glass plate at the edge of the droplet and a tangent from the glass plate at the periphery of the hemispherical) is preferably about 5° to 10° at the base of the hemispherical (or droplet) and preferably about 15° to 30° at half the height of the hemispherical or droplet.

[0027] The shape of a semi-ellipsoid is represented as an approximation of the actual shape of an ink droplet for descriptive purposes. Therefore, minute deviations from this shape are negligible for describing the ink droplet.

[0028] Furthermore, the glass panel may be provided with a second outer glass panel or outer window panel, which is laminated on the side of the glass panel having the printed portion by means of a cover layer. This provides a composite glass panel.

[0029] The outer glass panel or outer window panel of a composite glass assembly can be either transparent or opaque. In principle, light transmission is not necessary when the vehicle glass assembly is intended to provide ambient lighting. Therefore, the vehicle glass assembly can also be transparent or opaque. A preferred embodiment has a light transmittance of <20%, particularly preferably <10% (TL according to ISO 11664).

[0030] The glass sheet can be made of materials such as quartz glass, monolithic float glass, or ESG or TVG (partially prestressed glass), and can also be made of plastics such as polycarbonate.

[0031] At least one light source for guiding light into the lighting device or such lighting device is preferably arranged at one of two laterally opposing edges or edge regions of a glass plate or a composite glass plate having a glass plate, wherein such lateral edges relate to the left and right edges of the glass plate or composite glass plate arranged on the roof of the vehicle and being substantially rectangular. Light coupling of the light from the light source can be achieved via the side edges of the glass plate, or via the side surface at the side edges of the glass plate, or via an edge strip (Randstreifen) on the inner or lower main surface of the glass plate, for example by means of an optical prism (as disclosed in WO 2023 / 031460 A1) or other optical light guides or light coupling devices arranged on the edge strip.

[0032] Furthermore, a substantially perpendicular light coupling can be provided from below via the inner or lower main surface of the glass plate. In this case, for example, an optical device, such as a diffusion layer or diffusion element, is provided, which is arranged opposite the light coupling or light source (e.g., arranged on the inner main surface of the second glass plate). The optical device scatters or deflects the coupled light so that the coupled light is deflected primarily at an angle guided by internal total internal reflection within the second glass plate. Attached Figure Description

[0033] The invention will now be described in more detail with reference to the accompanying drawings and embodiments of a vehicle glass assembly according to the invention. The drawings show: Figure 1 A vehicle with a roof featuring vehicle glass components is shown in perspective. Figure 2 A light guide glass plate of a vehicle glass assembly is schematically shown in cross-section, the light guide glass plate having light reflection in the glass plate and light scattering at the printed portion of the glass plate covered by a cover layer; Figure 3 A cross-sectional view schematically shows an enlarged section of the light guide glass plate, illustrating light reflection and light scattering at the printed portion of the glass plate. Figure 4 A light guide glass plate is schematically shown in cross-section, the light guide glass plate having reflected light guiding and light scattering at the printed portion of the glass plate; and Figure 5 Another embodiment of the vehicle glass assembly is shown schematically in cross-sectional view. Detailed Implementation

[0034] Vehicles (e.g., passenger cars) include the vehicle roof 1 ( Figure 1The vehicle roof 1 has a roof opening 2 in which a vehicle glass assembly 3 is arranged. The vehicle glass assembly 3 is either fixedly arranged in the roof opening 2 or constructed as a roof cover, which is movably supported in the roof opening 2 by means of a support device and adjustable between a closed position and a ventilated position or an open position in a manner known per se. The vehicle glass assembly 3 can also be a fixed part or section of a roof module or panoramic roof. Lighting devices 4 are arranged at each of the two laterally opposed edge regions 5 of the vehicle glass assembly 3 and preferably extend along the corresponding side edge 7 of the vehicle glass assembly 3 at the inner side 6 of the glass panel.

[0035] The vehicle glass assembly 3 specifically comprises a composite glass panel having the following components: a glass panel 8 as an inner window panel, an outer window panel 9, and a polymer cover layer 10 as a connecting layer, which connects the glass panel 8 to the outer window panel 9 and includes, for example, a laminate, a laminated film, or a hot melt adhesive film, particularly made of PVB, TPU, or EVA. The outer window panel 9 is, for example, a tinted glass panel, which can be either transparent or opaque. The inner glass panel 8 is particularly a transparent and light-guiding glass panel or a light-transmitting glass panel, preferably made of low-iron glass, which forms a light-guiding layer for coupled light. The cover layer 10 covers a printed portion 11 arranged on the inner main surface 12 of the glass panel 8. The printed portion 11 is made of ink, which is preferably sprayed or printed onto the glass panel 8 by a digital printing method. Individual ink droplets 13 formed by the ink form a light-scattering structure of the printed portion 11.

[0036] Lighting device 4 (in) Figure 2 (Schematably represented as a light source) For example, multiple LEDs or RGB-LEDs are included as light sources. These light sources are arranged along the side edges 7 of the glass plate 8, and the light from these light sources is coupled into the glass plate 8, for example, via the side surface 14 on the edge side. The coupled light beam 15 is reflected in the glass plate 8 at the inner interface 16 and the outer interface 17. The inner interface 16 coincides with the inner main surface 12 covered by the cover layer 10. The outer interface 17 coincides with the outer or lower main surface 18 of the glass plate 8 facing the vehicle interior space.

[0037] The glass panel 8 has a low-emissivity layer or Low-E layer 19 on its outer or lower main surface 18. This Low-E layer 19 reduces solar energy radiated into the vehicle and thermal radiation emitted from the vehicle's interior space, thereby alleviating the cold feeling of the vehicle occupants.

[0038] The glass plate 8 has a refractive index n preferably of 1.505. G The printing section 11, or the scattering structure, or the ink droplet 13 has a refractive index n of 1.485 to 1.505, and particularly 1.50. PThe capping layer 10 has a refractive index n of, in particular, of 1.485. D .

[0039] A light beam 15 incident on interfaces 16 and 17 at an angle α less than the critical angle for total internal reflection is totally internally reflected in glass plate 8 and will not exit glass plate 8 via interfaces 16 and 18. The critical angle for total internal reflection (measured between the light beam and the interface) is determined by the following formula: α D = 90°-arcsin(n D / n G For n D = 1.485 and n G = 1.505, critical angle α D = 9.35°. Therefore, at this critical angle, only the light beam 15, which is oriented very flatly toward the interface 16, is totally reflected at the interface 16 of the glass plate 8 toward the cover layer 10. Thus, the glass plate 8 acts as a photoconductor for such a flatly oriented light beam.

[0040] A light beam 15, directed at the inner interface 16 onto the ink droplet 13 of the light scattering structure of the printing section 11, enters the ink droplet 13 at a corresponding angle and refractive index, and is reflected at the interface between the ink droplet 13 and the covering layer 10 covering the ink droplet 13, and is emitted as scattered light through the lower main surface 18 toward the vehicle interior space. This produces ambient lighting.

[0041] The printing section 11 of the glass plate 8 is achieved using transparent ink via inkjet digital printing. Preferably, the ink is UV-curable, for example, a mixture containing monomers, oligomers, photoinitiators, additives, and scattering particles. The printing ink is sprayed onto the glass plate 8 in very small, spaced-apart droplets. In this digital printing, the preferred resolution is in the range of 100 dpi to 1000 dpi (dots per inch), and particularly preferably in the range of 360 dpi to 450 dpi.

[0042] In one embodiment, adjacent droplets fuse together after printing and form a common printed surface on the glass plate 8. Therefore, these adjacent droplets can no longer be distinguished as separate (or individual) droplets. This behavior is related to the surface tension of the ink and the glass plate.

[0043] When the ink is printed onto the glass plate 8, the resulting ink droplets 13 are irradiated with UV light to trigger ink polymerization and cure the droplets 13. The UV light source is typically a special lamp that emits UV light with a specific wavelength that is matched to the ink for optimal curing. This curing can proceed very quickly, usually within seconds.

[0044] The scattering structure or ink droplets 13 can be printed over the entire area of ​​the printing section, for example, in a uniform grid pattern. The ink droplets 13 can also be printed according to a desired design, such that they are printed in a pattern, for example, with ink droplets 13 of different sizes and different spacing between them. The ink droplets 13 can also be printed with different thicknesses or heights, as well as different sizes or diameters.

[0045] The size or diameter of the scattering structure or ink droplet 13 is preferably in the range from 0.035 mm, and particularly in the range from 0.035 mm to 0.15 mm.

[0046] The refractive index n of the scattering structure or ink droplet 13 P It is produced by the mixing of the refractive index of the ink matrix and the refractive index of the scattering particles contained in the ink.

[0047] By selecting a refractive index n M The ink matrix material and having a refractive index n B The scattering particles and their volume fraction in the ink, and the refractive index n of the scattering structure. P In n M and n B It is set within the range between.

[0048] Inks used in UV-curable inkjet printing comprise ink mixtures consisting of monomers, oligomers, photoinitiators, and additives. These components provide a liquid ink that is printed onto a substrate such as a glass plate and rapidly cured by UV light. Monomers and oligomers are the basic components of the ink and form most of its physical properties. Photoinitiators are added to the ink to initiate the curing process upon exposure to UV light. Additives can be added to improve ink adhesion, print quality, and other properties. Some common materials used in UV-curable inkjet inks are acrylates, epoxy resins, polyurethanes, and polyesters. The refractive index of UV-curable inkjet inks varies depending on the ink composition and the materials used, and generally falls within the range of approximately 1.40 to 1.60.

[0049] To achieve light scattering at ink droplets, scattering particles with a higher refractive index difference relative to the surrounding matrix or liquid of the ink are added to the ink mixture. These scattering particles can be made of different materials. Some examples of scattering particles and their refractive indices are: silicates (n = 1.50 to 1.54), titanium dioxide (n = 2.35 to 2.55), barium sulfate (n = about 1.64), and calcium carbonate (n = 1.48 to 1.66). By adding scattering particles that scatter light in the visible light wavelength range, light is scattered within the ink droplets, thereby achieving diffused ambient lighting. The size, shape, and distribution of the scattering particles affect the intensity and type of light scattering. It should be noted that an increased concentration of scattering particles may increase the viscosity of the ink and impair print quality.

[0050] The dielectric constant of the scattering structure can be derived, for example, from the dielectric constant ε of the matrix according to the effective medium theory (Maxwell-Garnett-Theorie). m and the dielectric constant ε of the inclusion body i and the volume fraction δ of the inclusions i To calculate: For non-magnetic materials, the dielectric constant is equal to the square of the refractive index.

[0051] For example, for an acrylate-based UV resin matrix (n = 1.4, ε = 1.96), and with the addition of TiO2 particles (for TiO2: n = 2.6, ε = 6.76), the refractive index n of the printing section or ink depends on the volume fraction of the TiO2 particles. P It can be set to 1.4 to 2.6.

[0052] In one embodiment, the light coupling on the edge side can be configured such that the light coupling occurs inside the vehicle glass assembly 3, for example, in the case of a composite glass panel, by means of an illumination device 4 arranged inside the composite glass panel, and / or by means of the arrangement of the illumination device 4 at one of the interfaces 16, 17.

[0053] The light guided in the light guide glass plate 8—as explained above—is confined at the critical angle α of total internal reflection. The incident light is focused L1 ( Figure 3 The beam is totally reflected and continues to be guided as beam L2 in glass plate 8 (when the beam travels more smoothly than the critical angle α); and when the beam is incident more steeply (i.e. at an angle α greater than the critical angle), the beam penetrates into the covering layer 10 as beam L3.

[0054] The refractive index n of the scattering structure or ink droplet 13 P The refractive index n of glass plate 8 GTogether, determine which fractions of the guiding light L2 can penetrate the scattering structure or ink droplet 13 as beam L4, and which fractions are totally reflected at interface 16 as beam L5.

[0055] The incident angle of the guided light beam L2 is based on α D = 90°-arcsin(n D / n G The upward direction is restricted. Simultaneously, only those with at least an incident angle α... P = 90°-arcsin(n P / n G Only light can enter the ink droplet 13.

[0056] In order to couple light into ink droplet 13, the refractive index n of ink droplet 13 is therefore... P It must be greater than the refractive index n of the coating layer. D (n) P >n D ).

[0057] In addition, it can be determined by the refractive index n P To set: Beam L4 at α P and α max Within which angle range does the ink droplet 13 enter? Between 0° and α... P At a flat incident angle within the range, the beam is totally internally reflected as beam L5. Therefore, beam L5 will not couple out from glass plate 8.

[0058] The light guided in glass plate 8 (see Figure 4 The light is reflected at interface 16 relative to the cover layer 10 and at interface 17 relative to the Low-E layer 19. Along its path to the ink droplet 13, the light is reflected multiple times. In each reflection at the Low-E layer 19, the light is reflected according to the angle of incidence and wavelength. Here, a color shift occurs due to uneven reflection at the Low-E layer 19, which becomes stronger with each further reflection at the Low-E layer 19. For example, if white light is emitted from the RGB-LED of the lighting device 4 as a combination of red, green, and blue, and less red or blue is reflected in the reflection, then in the light coupling at the ink droplet 13, not white light but cyan-green light is scattered and coupled out. Such color shift should at least be reduced or completely avoided.

[0059] Experimental results and optical simulations of internal reflections at Low-E layer 19 show that inhomogeneities in spectral reflections increase strongly with flatter incident angles. Therefore, it is advantageous to prevent light incident at flat incident angles (e.g., <3°) from being coupled into the printed structure.

[0060] According to the present invention, the refractive index n of ink droplet 13P The volume fraction and material of the scattering particles are set such that only light L4 at a larger reflection angle enters the ink droplet 13. Here, light incident on the interface at a flat angle is blocked, thereby reducing at least color drift.

[0061] The greater the proportion of light coupled into ink droplet 13, the brighter the light emitted by ink droplet 13 or the light scattering structure. The intensity of light coupling is related to the refractive index n of the scattering structure or ink droplet 13. P The dependence indicates that it is advantageous to couple as much light as possible. The ratio of coupled light L4 to uncoupled light L5 is determined by the refractive index n. P and n D This is determined by [the principle of] ... P >= n G The maximum optical coupling occurs, and for n P = n D Non-coupled light.

[0062] For high intensity ambient lighting, it is advantageous to set the refractive index n of the ink droplet 13 or the printing section 11 relative to the cover layer 10. D Large refractive index n P (n) P >n D ).

[0063] Therefore, according to the present invention, the trade-off between high intensity and reduced color drift results in a decrease in the refractive index n of the scattering structure (or ink droplets 13) of the printing section 11. P The refractive index n of the glass plate is determined. G The refractive index n of the capping layer 10 D between.

[0064] According to another embodiment ( Figure 5 The vehicle glass assembly includes a modified structure in which the outer window panel 9 has an IR reflective coating 21 on its inner main surface 20 and a black printed portion 22 in the region of the side edge 7. The black printed portion 22 shields the lighting device 4 arranged therein at the edge region and blocks unwanted transmitted light from the lighting device 4. The intermediate layer between the outer window panel 9 and the inner glass panel 8 includes a laminate layer 23 in addition to the cover layer 10. The laminate layer 23 is connected to the outer window panel 9 and is formed, for example, from dark PVB. Furthermore, a switchable film 24 (e.g., PDLC (polymer dispersed liquid crystal)) is embedded between the cover layer 10 and the laminate layer 23. A frame 27 (e.g., made of PVB or TPU) surrounds the film 24 to compensate for thickness differences at the edges of the switchable film 24. The switchable film 24 is powered via a contact connection 25. The contact connection 25 is connected to an energy supply device (not shown) via a contact area (not shown).

[0065] Optical coupling originates from a light source (such as at least one LED or RGB-LED of the lighting device 4) and proceeds via an optical prism 26, which is bonded to the lower part or outer main surface 18 of the glass plate 8 in an area vacated from the Low-E layer. Optical coupling is performed, for example, according to optical coupling known from WO 2023 031 460 A1.

[0066] At least one of the capping layer 10, the laminate layer 23, or the switchable film 24 may have low light transmittance to achieve an overall transmittance TL of <20% or <10%.

[0067] Instead of or attached to the prism 26 shown herein, another method of coupling light into the light guide glass plate 8 can be chosen, such as radiating light from a light source of the lighting device (e.g., the top LED) toward the light guide glass plate, and combining a scattering unit with the light source, thereby reflecting and / or refracting the incident light into the glass plate to guide the light within the light guide glass plate by means of total internal reflection. The top LED is characterized in that it radiates light substantially perpendicular to the LED's mounting device (e.g., a circuit board), i.e., primarily in a radiation cone of less than 125°, particularly less than 90°, and preferably less than 60°.

[0068] The edge region 5 through which light is coupled into the glass plate 8 therefore includes both the outer side edge 7 and the edge strip 28 in the region of the lower main surface 18 of the glass plate 8 (in Figure 5 (Exemplary illustration and annotation). The edge strip 28 suitably has a width ranging from, for example, 0.5 cm to 10 cm. This width is related to the shape of, for example, the glass plate or composite glass plate in the area of ​​its side edge or edge region.

[0069] In principle, the printed light guide glass plate 8 is intended for use in both transparent and opaque vehicle glass assemblies with ambient lighting.

[0070] List of reference numerals 1. Vehicle roof 2. Roof opening 3. Vehicle glass components 4 lighting fixtures 5. Edge Area 6. Inner side of window panel 7 Side edges 8 Glass Plates 9. Exterior window panels 10 Covering layer 11 Printing Department 12 Main interior surface 13 Ink Drops 14. Side view 15 beams of light 16 Internal Interface 17 External Interface 18 lower main surface 19 Low-E layers 20 main side 21 Coating 22 Black Printing Department 23-layer laminate 24 Switchable Thin Film 25 Contact connection part 26 Prisms 27 Framework 28. Edge stripe.

Claims

1. A vehicle glass assembly (3) having a light guide glass plate (8) having a printed portion (11), the vehicle glass assembly having light coupling that couples light from an illumination device (4) into the glass plate (8) via an edge region (5) of the glass plate (8), and light coupling that couples the coupled light out of the glass plate (8) by means of the printed portion (11) of the glass plate (8). in, The printed section (11) is formed as a light-scattering structure by ink printed on the glass plate (8), and Wherein, the polymer capping layer (10) covers the light scattering structure, and The vehicle glass assembly has a low-emissivity coating (19) on the glass panel (8). Its features are, The refractive index n of the glass plate (8) G The refractive index n of the printed part (11) P and the refractive index n of the capping layer (10) D In the following relationship: n G ≥ n D And n P ≥ n D .

2. The vehicle glass assembly (3) according to claim 1. Its features are, The refractive index measured at 589.33 nm is: n G ≥ 1.5, n D ≤ 1.49 and n P > 1.48, especially n G > 1.5 and n D ≤ 1.

49.

3. The vehicle glass assembly (3) according to claim 1 or 2. Its features are, The ink contains scattering particles that determine the refractive index n of the printed portion (11) or the light scattering structure. P ,and The volume fraction of the scattering particles is determined relative to the refractive index n to be set for the printed portion (11) or the light scattering structure. P To choose, and The volume fraction of the scattering particles is greater than 20%, and preferably in the range of 20% to 50%.

4. The vehicle glass assembly (3) according to any one of claims 1 to 3. Its features are, The light scattering structure is formed by individual ink droplets (13), which are spaced apart from each other.

5. The vehicle glass assembly (3) according to claim 4. Its features are, Individual ink droplets (13) have an average diameter ranging from 0.05 mm to 0.1 mm.

6. The vehicle glass assembly (3) according to claim 4 or 5. Its features are, The ink droplets (13) are printed in the form of lenses or semi-ellipsoids.

7. The vehicle glass assembly (3) according to any one of claims 1 to 6. Its features are, The glass plate (8) and the second outer glass plate (9) provide a composite glass plate, the second outer glass plate being laminated on the side of the glass plate (8) having the printed portion (11) by means of the cover layer (10).

8. The vehicle glass assembly (3) according to any one of claims 1 to 7. Its features are, The glass plate (8) is formed of iron-poor glass, wherein the iron oxide content of the iron-poor glass is < 0.05% and preferably < 0.02%.

9. The vehicle glass assembly (3) according to any one of claims 1 to 8. Its features are, The intensity of the light coupled out at the light scattering structure is optimized by adjusting the refractive index of the light scattering structure according to n. P > (n G + n D Use ) / 2 to set it.

10. The vehicle glass assembly (3) according to any one of claims 1 to 9. Its features are, For light transmitted through the vehicle glass assembly (3), the optical distortion at the light scattering structure is optimized by adjusting the refractive index of the light scattering structure according to n. P < (n G + n D Use ) / 2 to set it.

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