Vehicular window glass

Abstract

Vehicular window glass according to one embodiment of the present disclosure comprises: a first glass sheet (11); a second glass sheet (12); intermediate adhesive layers (13, 14) disposed between the first glass sheet (11) and the second glass sheet (12); a light source (31) for causing light to enter the second glass sheet (12); and light scattering means (16, 17) configured to allow light that has entered from the light source (31) to exit to the outside. The light that has entered from the light source (31) passes through the second glass sheet (12) and the intermediate adhesive layer (13), and is then guided through the first glass sheet (11). In a plan view of the first glass sheet (11), if a region located toward an end of the first glass sheet (11) is defined as a first region (51) and a region more centrally located than the first region (51) is defined as a second region (52), the visible light transmittance of the first region (51) is greater than the visible light transmittance of the second region (52).

Description

Vehicle window glass

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to vehicle glazings.

[0002] It has been studied to make vehicle window glass luminous to provide lighting effects or notifications to people inside or outside the vehicle. For example, Patent Document 1 discloses a technology relating to luminous glazing that can be used as ambient lighting for the vehicle interior by arranging a light source on the edge surface of a glass plate, guiding light from the light source within the glass plate, and introducing the guided light into the vehicle interior using a light diffusing means.

[0003] Patent Document 2 discloses a technology relating to window glass that can be used as a high-mounted stop lamp for a vehicle, in which a light source is placed inside the glass plate, light from the light source is guided through the glass plate, and the guided light is then emitted outside the vehicle cabin using a hologram sheet.

[0004] Special Publication No. 2013-517989 Publication No. 7-126046

[0005] However, vehicle window glass is sometimes required to provide privacy, and in order to provide privacy, a colored glass plate or a colored intermediate adhesive layer is sometimes used as an intermediate adhesive layer in laminated glass.

[0006] However, when a colored glass plate or a colored intermediate adhesive layer is used in a light-emitting vehicle window glass, there is a problem that the light emitted from the light source is attenuated by the colored glass plate or the colored intermediate adhesive layer. This can reduce the amount of light entering the vehicle cabin, cause unevenness in the light entering the vehicle cabin, or cause a difference in color between the light emitted from the light source and the light entering the vehicle cabin. Therefore, there has been a need for a technology that allows light to be emitted from a vehicle window glass while ensuring privacy.

[0007] In view of the above-mentioned problems, an object of the present disclosure is to provide a vehicle window glass that can emit light from the vehicle window glass while ensuring privacy.

[0008] A vehicle window glass according to one aspect of the present disclosure is as follows.

[0009] [1] A vehicle window glass comprising: a first glass plate having a first main surface and a second main surface; a second glass plate having a third main surface and a fourth main surface; an intermediate adhesive layer disposed between the first glass plate and the second glass plate; a light source that causes light to be incident on at least one of the second glass plate and the intermediate adhesive layer; and light scattering means configured to allow the light incident from the light source to be extracted to the outside from the first main surface, wherein the second main surface and the third main surface face each other; the first glass plate is disposed on the outside of a vehicle and the second glass plate is disposed on the inside of the vehicle; the light incident from the light source is configured to pass through at least one of the second glass plate and the intermediate adhesive layer and then be waveguided through the first glass plate; and wherein, in a plan view of the first glass plate, a region located on an edge side of the first glass plate is defined as a first region and a region located closer to the center than the first region is defined as a second region, and the visible light transmittance of the first region is greater than the visible light transmittance of the second region.

[0010] [2] The vehicle window glass according to [1], wherein in the second region, the intermediate adhesive layer has a first colored layer.

[0011] [3] The vehicle window glass according to [2], further comprising a low refractive index layer between the first glass plate and the first colored layer.

[0012] [4] The vehicle window glass according to [3], wherein the refractive index of the low refractive index layer is 1.45 or less.

[0013] [5] The vehicle window glass according to [3], wherein the low refractive index layer contains a fluororesin.

[0014] [6] The vehicle window glass according to [3], wherein the light scattering means is provided between the first glass plate and the low refractive index layer.

[0015] [7] The vehicle window glass according to [3], wherein the light scattering means is provided between the first glass plate and the low refractive index layer, and between the second glass plate and the first colored layer.

[0016] [8] The vehicle window glass according to [1], wherein the first glass plate has a band-shaped shielding region on an end side of the first glass plate in a plan view, and the first region is provided between the shielding region and the second region.

[0017] [9] The vehicle window glass according to [8], wherein in the shielding region, the first glass plate has a first shielding layer on the second main surface.

[0018]

[10] The vehicle window glass according to [8], wherein the intermediate adhesive layer has a second colored layer in the shielding region.

[0019]

[11] The vehicle window glass according to [8], wherein in the shielding region, the second glass plate has a second shielding layer on the fourth main surface, and the light source is disposed at a position that does not overlap with the second shielding layer in a plan view of the second glass plate.

[0020]

[12] In a plan view of the second glass plate, the second glass plate has a third shielding layer in a region including a boundary between the first region and the second region of the fourth main surface. The vehicle window glass according to any one of [8] to

[11] .

[0021]

[13] The vehicle window glass according to [1] or [2], wherein the light source causes light to be incident on the fourth main surface of the second glass plate.

[0022]

[14] The vehicle window glass according to [1] or [2], wherein the first region has a visible light transmittance of 70% or more.

[0023]

[15] The vehicle window glass according to [1] or [2], wherein the visible light transmittance of the second region is 20% or less.

[0024]

[16] The vehicle window glass according to [1] or [2], wherein the visible light transmittance of the first glass plate is equal to or greater than the visible light transmittance of the second glass plate.

[0025]

[17] The vehicle window glass according to [1] or [2], wherein an optical element that causes irradiation light from the light source to be incident on the fourth main surface of the second glass plate is provided on the fourth main surface, and when a distance d is defined as a distance between an end of the optical element on a side where light is introduced from the light source and an end of the optical element on the second region side, the relationship 0 mm<d<120 mm is satisfied.

[0026] The present disclosure makes it possible to provide a vehicle window glass that is capable of emitting light from the vehicle window glass while ensuring privacy.

[0027] FIG. 1 is a plan view showing an example of the configuration of a vehicle window glass according to an embodiment; FIG. 2 is a cross-sectional view showing an example of the configuration of a vehicle window glass according to an embodiment; FIG. 3 is a cross-sectional view showing another example of the configuration of a vehicle window glass according to an embodiment; FIG. 4 is a cross-sectional view showing another example of the configuration of a vehicle window glass according to an embodiment; FIG. 5 is a cross-sectional view showing another example of the configuration of a vehicle window glass according to an embodiment; FIG. 6 is a cross-sectional view showing another example of the configuration of a vehicle window glass according to an embodiment; FIG. 7 is a cross-sectional view showing another example of the configuration of a vehicle window glass according to an embodiment;

[0028] Hereinafter, an embodiment will be described with reference to the drawings. FIG. 1 is a plan view showing an example of the configuration of a vehicle window glass according to an embodiment. FIG. 2 is a cross-sectional view showing the example of the configuration of a vehicle window glass according to an embodiment, taken along the section line II-II in FIG. 1. A vehicle window glass 1 according to this embodiment can be used, for example, as a vehicle window. Examples of vehicle windows include roof glass, windshields, side windows, rear windows, etc. In this embodiment, a case will be described in which the vehicle window glass is a roof glass, as an example.

[0029] The vehicle window glass 1 according to this embodiment is configured to use a light source 31 (see FIG. 2 ) provided on an end side (first region 51) of the vehicle window glass 1 to introduce light from the end side of the vehicle window glass 1 into the interior of the vehicle window glass 1 (central portion: second region 52), and to scatter the light on the surface or inside of the vehicle window glass 1 to extract the light to the outside. Note that in this embodiment, the light incident from the light source 31 may be extracted both to the outside of the vehicle cabin and into the vehicle cabin. FIGS. 2 to 9 , which will be described below, illustrate an example configuration in which light incident from the light source is extracted both to the outside and the inside of the vehicle cabin. Also, FIGS. 10 to 12 illustrate an example configuration in which light incident from the light source is extracted only to the outside of the vehicle cabin. Note that while FIGS. 2 to 12 illustrate one end side of the vehicle window glass 1, the other end side of the vehicle window glass 1 may also have a similar configuration in this embodiment. In other words, in this embodiment, both end sides of the vehicle window glass 1 may have the same configuration.

[0030] When the vehicle window glass 1 according to this embodiment is used as a roof glass, it is possible to illuminate the exterior of the vehicle cabin or the ceiling portion of the vehicle cabin in a predetermined color, thereby improving the design of the exterior and interior of the vehicle cabin. It can also be used to notify people outside the vehicle cabin or occupants inside the vehicle cabin. Examples of information notification include, but are not limited to, hazard alerts and vehicle status notifications. The light extracted to the outside of the vehicle window glass 1 can be used for various purposes depending on the location of the vehicle where the vehicle window glass 1 is installed.

[0031] As shown in Figure 2, the vehicle window glass 1 according to this embodiment comprises a first glass plate 11 having a first main surface 21 and a second main surface 22, a second glass plate 12 having a third main surface 23 and a fourth main surface 24, and intermediate adhesive layers 13, 14 arranged between the first glass plate 11 and the second glass plate 12. The second main surface 22 and the third main surface 23 are arranged to face each other. When the vehicle window glass 1 is attached to a vehicle, the first glass plate 11 is arranged on the outer side of the vehicle, and the second glass plate 12 is arranged on the inner side of the vehicle.

[0032] In this embodiment, in a plan view of the first glass plate 11, a region located on the edge side of the first glass plate 11 is defined as a first region 51, and a region located closer to the center than the first region 51 is defined as a second region 52. An intermediate adhesive layer 13 is provided in the first region 51, and an intermediate adhesive layer 14 is provided in the second region 52. Furthermore, a low refractive index layer 15 is provided in the second region 52. A light scattering means 16 is provided between the first glass plate 11 and the low refractive index layer 15. A light scattering means 17 is provided between the second glass plate 12 and the intermediate adhesive layer 14. In this embodiment, a light source 31 is provided that emits light to at least one of the second glass plate 12 and the intermediate adhesive layer 13. The light source 31 is provided in the first region 51. In the configuration example shown in FIG. 2 , the light source 31 emits light 33 and 34 to the fourth main surface 24 of the second glass plate 12. Specifically, the light source 31 emits light 33 and 34 incident on the fourth main surface 24 of the second glass plate 12 via the optical element 32. In the configuration example shown in Fig. 2, both the light source 31 and the optical element 32 are fixed to the fourth main surface 24 of the second glass plate 12, but this is not limiting. For example, the light source 31 may be attached to the optical element 32 and not fixed to the second glass plate 12. Furthermore, at least one of the light source 31 and the optical element 32 may be detachable.

[0033] Light 33 incident from the light source 31 passes through the second glass plate 12 and the intermediate adhesive layer 13, is guided through the first glass plate 11, is scattered by the light scattering means 16, and is extracted to the outside (outside the vehicle cabin) from the first main surface 21. Light 34 incident from the light source 31 is guided through the second glass plate 12, is scattered by the light scattering means 17, and is extracted to the outside (inside the vehicle cabin) from the fourth main surface 24.

[0034] The vehicle window glass 1 according to this embodiment may be flat or curved. It may also have a shape including both flat and curved surfaces. The first glass sheet 11 and the second glass sheet 12 may each be flat or curved, but it is preferable that at least one of them is curved because this makes it easier to ensure the strength of the laminated glass, and it is more preferable that both are curved. The curved sheet may have a single-curved shape curved in one direction, or a three-dimensional shape curved in two or more directions. The three-dimensional shape may be, for example, a complex-curved shape curved in two orthogonal directions. This specification describes a case where both the first glass sheet 11 and the second glass sheet 12 are flat, but the same explanation applies when at least one of them is curved.

[0035] The outer edge shape of the first glass plate 11 and the second glass plate 12 in a plan view may be any shape, but is preferably rectangular (see FIG. 1 ). The first and second glass plates 11 and 12 may be made of, for example, transparent inorganic glass. The first and second glass plates 11 and 12 may be made of, for example, soda-lime glass, aluminosilicate glass, borosilicate glass, alkali-free glass, quartz glass, or the like. The first and second glass plates 11 and 12 may also be made of organic glass (resin). Examples of organic glass that may be used include polycarbonate resin, polystyrene resin, aromatic polyester resin, acrylic resin, polyester resin, polyarylate resin, polycondensate of halogenated bisphenol A and ethylene glycol, acrylic urethane resin, and halogenated aryl group-containing acrylic resin.

[0036] As an example, the refractive index of the first and second glass plates 11, 12 is approximately 1.52. The visible light transmittance of the first and second glass plates 11, 12 is 80% or more. In this embodiment, the visible light transmittance of the first glass plate 11 may be configured to be equal to or greater than the visible light transmittance of the second glass plate 12. Increasing the transmittance of the glass plates in this way makes it easier to improve light guide efficiency and reduce color change.

[0037] The thickness of each of the first and second glass sheets 11, 12 is, for example, 0.1 mm to 10 mm, and is preferably 0.3 mm or more, more preferably 0.5 mm or more, from the viewpoint of resistance to stone chipping. Furthermore, in order to reduce the mass of the vehicle window glass 1, the thickness of each of the first and second glass sheets 11, 12 is preferably 3 mm or less, more preferably 2.6 mm or less, and even more preferably 2.1 mm or less. The upper and lower limits of the above numerical ranges can be arbitrarily combined, for example, 0.3 mm to 3.0 mm, 1.1 mm to 2.6 mm, or 1.7 mm to 2.1 mm. The thicknesses of the first and second glass sheets 11, 12 may be the same or different. For example, the thickness of the first glass sheet 11 located on the vehicle exterior side may be thicker than the thickness of the second glass sheet 12 located on the vehicle interior side. Increasing the thickness of the first glass plate 11 disposed on the vehicle exterior side in this manner improves the strength of the vehicle window glass 1 against objects flying toward the vehicle window glass 1 .

[0038] The intermediate adhesive layers 13, 14 and the low refractive index layer 15 are arranged so as to be sandwiched between the second main surface 22 of the first glass plate 11 and the third main surface 23 of the second glass plate 12. In other words, the first glass plate 11 and the second glass plate 12 are bonded together using the intermediate adhesive layers 13, 14 and the low refractive index layer 15. Specifically, when forming the vehicle window glass 1, the intermediate adhesive layer 13 is arranged between the first glass plate 11 and the second glass plate 12 in the first region 51. Furthermore, the intermediate adhesive layer 14, the low refractive index layer 15, and the light scattering means 16, 17 are arranged between the first glass plate 11 and the second glass plate 12 in the second region 52. These are then heated and pressurized to bond them together, thereby forming the vehicle window glass 1.

[0039] The light scattering means 16, 17 have a light scattering function. The light scattering means 16, 17 can be formed by mixing light-scattering particles such as silica, alumina, or titania with a binder and printing the mixture. The light scattering means 16, 17 are formed so that the light-scattering particles have a predetermined degree of aggregation. Alternatively, the light scattering means 16, 17 may be formed by etching the surface of the glass plate. The light scattering means 16, 17 may be formed over the entire second region 52 or may be formed partially in the second region 52. The light scattering means 16, 17 may be configured to have a predetermined pattern or design. In the non-light-scattering region, the low refractive index layer 15 and the second major surface 22 of the first glass plate 11 are in direct contact, and the intermediate adhesive layer 14 and the third major surface 23 of the second glass plate 12 are in direct contact.

[0040] The low refractive index layer 15 is an intermediate adhesive layer having a low refractive index. It is preferable that the low refractive index layer 15 is not provided between the light irradiated from the light source 31 and the first glass plate 11. This allows the light irradiated from the light source 31 to be efficiently incident on the first glass plate 11. It is preferable that the low refractive index layer 15 is located closer to the center than the end on the second region 52 side of the optical element 32. Note that in FIG. 2 , for simplicity of the drawing, the light scattering means 16, 17 are shown as a single layer, and the light scattering pattern is not shown.

[0041] In this embodiment, the intermediate adhesive layer 13 provided in the first region 51 is a transparent intermediate adhesive layer, and the intermediate adhesive layer 14 provided in the second region 52 is a colored and transparent intermediate adhesive layer (first colored layer). This configuration allows the visible light transmittance of the first region 51 to be greater than the visible light transmittance of the second region 52. For example, the visible light transmittance of the first region 51 is 70% or more, preferably 80% or more. The visible light transmittance of the second region 52 is 20% or less, preferably 10% or less, and more preferably 5% or less. The visible light transmittance of the second region 52 may be greater than 0%, and may be, for example, 1% or more, 2% or more, or 5% or more. The visible light transmittance of the first region 51 here refers to the visible light transmittance of the first region 51 in the thickness direction of the vehicle window glass 1 (excluding the portion where the light source 31 and the optical element 32 are provided). Similarly, the visible light transmittance of the second region 52 is the visible light transmittance of the second region 52 in the thickness direction of the vehicle window glass 1 .

[0042] In this embodiment, the visible light transmittance of the first region 51 is increased, so that attenuation of the light 33 from the light source 31 in the first region 51 is suppressed, allowing the light 33 to be introduced into the first glass plate 11. In addition, the visible light transmittance of the second region 52 is reduced, so that the interior of the vehicle compartment is less visible from outside the vehicle compartment. Thus, a vehicle window glass that can emit light from the vehicle window glass while ensuring privacy can be provided.

[0043] The intermediate adhesive layer 13 provided in the first region 51 can be made of any material as long as it is a transparent intermediate adhesive layer. Thermoplastic resins and curable resins are suitable for the intermediate adhesive layer 13, with thermoplastic resins being particularly suitable. For example, the intermediate adhesive layer 13 can be made of polyvinyl butyral (PVB) resin, ethylene vinyl acetate copolymer (EVA) resin, polyurethane resin, ionomer resin, cycloolefin polymer, etc. Among these, PVB resin, EVA resin, and polyurethane resin are preferred. The transmittance of the intermediate adhesive layer 13 is preferably 70% or more, more preferably 80% or more, and even more preferably 85% or more. The refractive index of the intermediate adhesive layer 13 is preferably 1.45 to 1.52, typically approximately 1.48. The thickness of the intermediate adhesive layer 13 is not particularly limited, but is preferably 2.4 mm or less. The thickness of the intermediate adhesive layer 13 is preferably 0.50 mm or more, preferably greater than 0.76 mm, and more preferably 0.80 mm or more.

[0044] The intermediate adhesive layer 14 provided in the second region 52 is a colored and transparent intermediate adhesive layer that has a light-absorbing function. Using a colored and transparent intermediate adhesive layer for the intermediate adhesive layer 14 provided in the second region 52 reduces the proportion of sunlight entering the vehicle interior from the outside. In other words, the intermediate adhesive layer 14 has light-blocking properties. The transmittance of the intermediate adhesive layer 14 is preferably 20% or less, more preferably 10% or less, and even more preferably 5% or less. The transmittance of the intermediate adhesive layer 14 may be greater than 0%, for example, 1% or more, or 2% or more. The refractive index of the intermediate adhesive layer 14 is preferably 1.45 or more and 1.52 or less, and is typically approximately 1.48. The thickness of the intermediate adhesive layer 14 is not particularly limited, but is preferably 2.4 mm or less. The thickness of the intermediate adhesive layer 14 is preferably 0.50 mm or more, preferably greater than 0.76 mm, and more preferably 0.80 mm or more.

[0045] The intermediate adhesive layer 14 may be made of a resin material containing a colorant. The colorant may be any pigment, dye, or the like. The resin material constituting the intermediate adhesive layer 14 may be at least one selected from the group consisting of polyvinyl butyral resin, ethylene vinyl acetate copolymer resin, polyurethane resin, ionomer resin, and cycloolefin polymer.

[0046] The low refractive index layer 15 is an intermediate layer having a refractive index lower than that of the intermediate adhesive layer 14. The low refractive index layer 15 is typically transparent, but may be colored any color. The refractive index of the low refractive index layer 15 is preferably 1.48 or less, more preferably 1.45 or less. The refractive index of the low refractive index layer 15 is preferably 1.32 or more, more preferably 1.35 or more. The thickness of the low refractive index layer 15 is preferably 1.10 mm or less, more preferably 0.8 mm or less, because this prevents excessive haze and makes it easy to ensure light transmittance. The thickness of the low refractive index layer 15 is preferably 0.03 mm or more, more preferably 0.05 mm or more, and even more preferably 0.10 mm or more.

[0047] The low refractive index layer 15 can be formed using at least one resin material selected from the group consisting of fluororesin, polyvinyl butyral resin, ethylene vinyl acetate copolymer resin, polyurethane resin, ionomer resin, and cycloolefin polymer. Alternatively, the low refractive index layer 15 may be formed using an acrylic, silicone, epoxy, or urethane acrylate optical clear adhesive (OCA). In particular, in this embodiment, it is preferable to form the low refractive index layer 15 using a fluororesin. Examples of fluororesins include ETFE (Ethylene tetrafluoroethylene), PTFE (Polytetrafluoroethylene), FEP (Fluorinated ethylene propylene), PCTFE (Polychlorotrifluoroethylene), PVDF (Polyvinylidene fluoride), and FEVE (Fluoroolefine vinyl ether copolymer), with ETFE being particularly preferred.

[0048] In the present embodiment, the difference in refractive index between the first glass plate 11 and the low-refractive-index layer 15 is preferably 0.05 or more, more preferably 0.07 or more, and even more preferably 0.09 or more. The difference in refractive index between the first glass plate 11 and the low-refractive-index layer 15 is preferably 0.2 or less. By setting the difference in refractive index between the first glass plate 11 and the low-refractive-index layer 15 to be within this range, light can be reflected at the interface between the first glass plate 11 and the low-refractive-index layer 15, and light can be propagated inside the first glass plate 11.

[0049] In the present embodiment, the difference in refractive index between the second glass plate 12 and the intermediate adhesive layer 14 is preferably 0.05 or more, more preferably 0.07 or more, and even more preferably 0.09 or more. The difference in refractive index between the second glass plate 12 and the intermediate adhesive layer 14 is preferably 0.2 or less. By setting the difference in refractive index between the second glass plate 12 and the intermediate adhesive layer 14 within this range, light can be reflected at the interface between the second glass plate 12 and the intermediate adhesive layer 14, allowing light to propagate within the second glass plate 12.

[0050] As an example, if the refractive index of the first glass plate 11 is 1.52 and the refractive index of the low refractive index layer 15 is 1.41 to 1.48, the incident angle θ1 of light 33 shown in Figure 2 is 70 degrees to 76 degrees. Furthermore, if the refractive index of the second glass plate 12 is 1.52 and the refractive index of the intermediate adhesive layers 13 and 14 is 1.48 to 1.52, the incident angle θ2 of light 34 shown in Figure 2 is 76 degrees to 90 degrees. For convenience of explanation, the angles θ1 and θ2 shown in Figure 2 are different from the incident angles θ1 and θ2 described above, but in this specification, the incident angles are set to be the above-mentioned θ1 and θ2.

[0051] The light scattering means 16 is provided between the first glass plate 11 and the low-refractive index layer 15. The light scattering means 16 scatters light 33 incident from the light source 31 toward the first main surface 21. In this embodiment, a pattern that scatters the light 33 is formed by the light scattering means 16, and in the region where the light 33 is not scattered, the second main surface 22 of the first glass plate 11 and the low-refractive index layer 15 are in direct contact. For example, the light scattering means 16 may be configured by forming a pattern that scatters the light 33 on the second main surface 22 of the first glass plate 11. Note that when the light scattering means 16 is formed by etching the surface of a glass plate, the second main surface 22 of the first glass plate 11 on which the light scattering means 16 is formed is in direct contact with the low-refractive index layer 15.

[0052] The light scattering means 17 is provided between the second glass plate 12 and the intermediate adhesive layer 14. The light scattering means 17 scatters light 34 incident from the light source 31 toward the fourth main surface 24. In this embodiment, a pattern that scatters the light 34 is formed by the light scattering means 17, and in the region where the light 34 is not scattered, the third main surface 23 of the second glass plate 12 and the intermediate adhesive layer 14 are in direct contact. For example, the light scattering means 17 may be configured by forming a pattern that scatters the light 34 on the third main surface 23 of the second glass plate 12. Note that if the light scattering means 17 is formed by etching the surface of a glass plate, the third main surface 23 of the second glass plate 12 on which the light scattering means 17 is formed will be in direct contact with the intermediate adhesive layer 14.

[0053] In this embodiment, a colored intermediate adhesive layer is provided as the intermediate adhesive layer 14, the first glass plate 11 is provided with the light scattering means 16, and the second glass plate 12 is provided with the light scattering means 17. Therefore, it is possible to make the display content displayed outside the vehicle cabin different from the display content displayed inside the vehicle cabin. In other words, by making the scattering patterns of the light scattering means 16 and the light scattering means 17 different from each other, it is possible to make the display content displayed outside the vehicle cabin different from the display content displayed inside the vehicle cabin.

[0054] The light source 31 is provided on the fourth main surface 24 of the second glass plate 12, and introduces light 33, 34 to the fourth main surface 24 of the second glass plate 12 via the optical element 32. A light emitting diode (LED), an organic EL element, or the like can be used as the light source 31. The light source 31 and the optical element 32 are provided in the first region 51.

[0055] The optical element 32 is provided on the fourth main surface 24 of the second glass plate 12. The optical element 32 is an element that changes the traveling direction of light irradiated from the light source 31 by refraction, reflection, or the like, and may have a lens function as needed. The optical element 32 has a light-receiving surface facing the light source 31, and the light source 31 introduces light to the light-receiving surface of the optical element 32. For example, the optical element 32 has an adhesive surface and is attached to the fourth main surface 24 so that the adhesive surface and the fourth main surface 24 are in direct contact with each other or are in contact with each other via an optical adhesive layer (not shown) made of an optical adhesive (OCA) or the like. The shape of the optical element 32 may be, for example, a flat plate or a triangular prism, but is not limited thereto. For example, the optical element 32 is made of glass or a resin material. For example, acrylic resin, epoxy resin, silicone rubber, or the like may be used as the resin material. It is preferable to use a transparent material for the optical element 32. The refractive index of the optical element 32 and the refractive index of the optical adhesive layer (not shown) that bonds the optical element 32 to the fourth main surface 24 of the second glass plate 12 are preferably 1.45 or more.

[0056] By providing the light source 31 and the optical element 32 on the fourth main surface 24 of the second glass plate 12, the distance from the light source 31 to the second region 52 can be shortened. This makes it possible to prevent the light emitted from the light source 31 from attenuating midway. Furthermore, because the light source 31 and the optical element 32 are disposed inside the vehicle cabin, it is possible to prevent water from hitting the light source 31 and the optical element 32.

[0057] As described above, in the vehicle window glass 1 according to this embodiment, the visible light transmittance of the first region 51 is set to be greater than the visible light transmittance of the second region 52. Because the visible light transmittance of the first region 51 is set to be greater, light 33 from the light source 31 can be efficiently introduced into the first glass sheet 11 in the first region 51. Furthermore, because the visible light transmittance of the second region 52 is set to be smaller, the interior of the vehicle cabin is less visible from outside the vehicle cabin. This provides a vehicle window glass that can emit light from the vehicle window glass while ensuring privacy. In this embodiment, a colored intermediate adhesive layer is used as the intermediate adhesive layer 14 disposed in the second region 52 in a plan view. The colored intermediate adhesive layer may have a heat ray absorbing function. This reduces the amount of heat rays reaching the vehicle cabin.

[0058] Next, modified examples of the vehicle window glass according to this embodiment will be described below. Figures 3 to 12 are cross-sectional views showing other configuration examples of the vehicle window glass according to this embodiment.

[0059] In the vehicle window glass 1a shown in FIG. 3 , an intermediate adhesive layer 18 is provided between the low refractive index layer 15 and the light scattering means 16 (first glass plate 11). In the configuration example shown in FIG. 2 , if a resin sheet such as a fluororesin is used as the low refractive index layer 15, the adhesive strength between the low refractive index layer 15 and the second main surface 22 of the first glass plate 11 may be insufficient. In the configuration example shown in FIG. 3 , in consideration of this issue, an intermediate adhesive layer 18 is provided in addition to the intermediate adhesive layer 14 in the second region 52 to bond the first glass plate 11 and the second glass plate 12. Specifically, the intermediate adhesive layer 18 is further provided between the second main surface 22 of the first glass plate 11 and the low refractive index layer 15. This configuration allows for strong bonding between the first glass plate 11 and the second glass plate 12. Note that the materials and compositions constituting the intermediate adhesive layer 18 and the intermediate adhesive layer 14 may be the same or different.

[0060] In this embodiment, the difference in refractive index between the intermediate adhesive layer 18 and the low refractive index layer 15 is preferably 0.05 or more, more preferably 0.07 or more, and even more preferably 0.09 or more. The difference in refractive index between the intermediate adhesive layer 18 and the low refractive index layer 15 is preferably 0.2 or less. By setting the difference in refractive index between the intermediate adhesive layer 18 and the low refractive index layer 15 to this range, light can be reflected at the interface between the intermediate adhesive layer 18 and the low refractive index layer 15, and light can be propagated inside the first glass plate 11 and the intermediate adhesive layer 18.

[0061] The vehicle window glass 1b shown in Fig. 4 has a low refractive index coating 19 instead of the low refractive index layer 15 shown in Fig. 2. The low refractive index coating 19 is formed on the second main surface 22 of the first glass plate 11. That is, in the configuration example shown in Fig. 4, the second main surface 22 of the first glass plate 11 is coated with light scattering means 16, and the low refractive index coating 19 is further applied so as to cover the light scattering means 16. In this case, the second region 52 of the first glass plate 11 and the second glass plate 12 are bonded together by the intermediate adhesive layer 14.

[0062] In the vehicle window glass 1c shown in Fig. 5, a light source 31 is provided on a side surface of the second glass sheet 12. With this configuration, light can be directly introduced from the light source 31 to the first glass sheet 11 and the second glass sheet 12. When the light source 31 is provided on the side surface of the second glass sheet 12, there is no need to provide a member such as a light source on the fourth main surface 24 side (the vehicle interior side) of the second glass sheet 12, thereby making it possible to increase the interior space of the vehicle. In addition, the use of the optical element 32 can be omitted.

[0063] The light source 31 may be provided on the side surface of the intermediate adhesive layer 13 , or may be provided so as to straddle the side surface of the second glass plate 12 and the side surface of the intermediate adhesive layer 13 .

[0064] The vehicle window glass 1d shown in FIG. 6 has a band-shaped shielding region 53 on the edge side of the first glass plate 11 in a plan view of the first glass plate 11. In this case, the first region 51 is provided between the shielding region 53 and the second region 52. In the shielding region 53, the first glass plate 11 has a first shielding layer 41 on the second major surface 22. In the shielding region 53, the second glass plate 12 has a second shielding layer 42 on the fourth major surface 24. As shown in FIG. 6 , the width of the second shielding layer 42 (the length in the left-right direction of the paper) may be shorter than the width of the first shielding layer 41. Furthermore, the second shielding layer 42 may be provided on the third major surface 23 of the second glass plate 12. The light source 31 is arranged at a position that does not overlap with the second shielding layer 42 in a plan view of the second glass plate 12. When the direction from the end of the second glass plate 12 toward the center is defined as positive, the distance from the position of the end of the optical element 32 on the side where light is introduced from the light source 31 to the position of the end of the first shielding layer 41 on the center side (positive direction side) is preferably more than −10 mm and less than 30 mm, more preferably more than 0 mm and less than 20 mm, and even more preferably more than 5 mm and less than 15 mm.

[0065] The first shielding layer 41 and the second shielding layer 42 may be formed, for example, by printing black ceramics on the second main surface 22 of the first glass plate 11 and the fourth main surface 24 of the second glass plate 12. Specifically, the first shielding layer 41 and the second shielding layer 42 may be formed by applying and firing a ceramic color paste including a fusible glass frit containing a black pigment. However, the method of forming the first shielding layer 41 and the second shielding layer 42 is not limited to this.

[0066] As in the vehicle window glass 1d shown in Fig. 6, by providing the first shielding layer 41 and the second shielding layer 42, it is possible to reduce light leakage from the light source 31. That is, it is possible to prevent the light from the light source 31 from directly leaking outside the vehicle compartment. In addition, it is possible to prevent sunlight from directly irradiating the light source 31 from outside the vehicle compartment, thereby improving the durability of the light source 31.

[0067] The vehicle window glass 1e shown in Fig. 7 has a band-shaped shielding region 53 on the edge side of the first glass plate 11 in a plan view of the first glass plate 11. In this case, the first region 51 is provided between the shielding region 53 and the second region 52. In the configuration example shown in Fig. 7, a colored intermediate adhesive layer (second colored layer) 45 is provided in the shielding region 53. The colored intermediate adhesive layer 45 may be made of the same material as the colored intermediate adhesive layer 14. The light source 31 is arranged at a position that does not overlap with the colored intermediate adhesive layer 45 in a plan view of the first glass plate 11.

[0068] 7, the provision of the colored intermediate adhesive layer 45 can reduce light leakage from the light source 31. That is, it is possible to prevent light from the light source 31 from directly leaking outside the vehicle compartment. In addition, it is possible to prevent sunlight from directly irradiating the light source 31 from outside the vehicle compartment, thereby improving the durability of the light source 31.

[0069] The vehicle window glass 1f shown in Fig. 8 is a configuration example that combines the vehicle window glass 1d shown in Fig. 6 and the vehicle window glass 1e shown in Fig. 7. That is, the vehicle window glass 1f shown in Fig. 8 has a band-shaped shielding region 53 on the edge side of the first glass plate 11 in a plan view of the first glass plate 11. The first region 51 is provided between the shielding region 53 and the second region 52. In the shielding region 53, the first glass plate 11 has a first shielding layer 41 on the second main surface 22. Furthermore, in the shielding region 53, the second glass plate 12 has a second shielding layer 42 on the fourth main surface 24. In this case, the light source 31 is arranged in a position that does not overlap with the second shielding layer 42 in a plan view of the second glass plate 12. Furthermore, the configuration example shown in Fig. 8 has a colored intermediate adhesive layer 45 in the shielding region 53.

[0070] The vehicle window glass 1f shown in FIG. 8 is provided with an optical element 32 on the fourth main surface 24 of the second glass sheet 12, which causes light emitted from a light source 31 to be incident on the fourth main surface 24 of the second glass sheet 12. The optical element 32 is provided in the first region 51. In this case, a distance d between an end of the optical element 32 on the side where light from the light source 31 is introduced and an end of the second region 52 on the optical element 32 side preferably satisfies 0 mm < d < 120 mm, more preferably satisfies 5 mm < d < 100 mm, and even more preferably satisfies 10 mm < d < 80 mm. By setting the distance d within these ranges, the light emitted from the light source 31 can be appropriately introduced into the first glass sheet 11 and the second glass sheet 12. In other words, the angles θ1 and θ2 shown in FIG. 2 can be set to appropriate angles, i.e., conditions for total reflection of light inside the first glass sheet 11 and the second glass sheet 12 can be achieved.

[0071] The vehicle window glass 1g shown in Fig. 9 is the vehicle window glass 1f shown in Fig. 8, to which a third shielding layer 43 has been added. That is, the vehicle window glass 1g shown in Fig. 9 has the third shielding layer 43 in a region including the boundary between the first region 51 and the second region 52 on the fourth main surface 24 of the second glass plate 12 in a plan view of the second glass plate 12. By providing the third shielding layer 43 in the region including the boundary between the first region 51 and the second region 52 in this way, the design of the vehicle window glass 1g can be improved when viewed from inside the vehicle cabin.

[0072] Next, a configuration in which light incident from a light source is extracted only to the outside of the vehicle cabin will be described with reference to Figures 10 to 12. The vehicle window glass 1h shown in Figure 10 corresponds to a configuration in which the light scattering means 17 is omitted from the vehicle window glass 1 shown in Figure 2. The configuration is otherwise the same as that of the vehicle window glass 1 shown in Figure 2. The vehicle window glass 1h shown in Figure 10 does not have the light scattering means 17 on the third main surface 23 of the second glass plate 12. Therefore, light incident from the light source 31 is not extracted to the inside of the vehicle cabin. On the other hand, the light scattering means 16 is provided on the second main surface 22 of the first glass plate 11. Therefore, light incident from the light source 31 is extracted to the outside of the vehicle cabin.

[0073] The vehicle window glass 1i shown in Fig. 11 differs from the vehicle window glass 1h shown in Fig. 10 in that a light source 31 is provided on a side surface of the second glass sheet 12. With this configuration, light can be introduced directly from the light source 31 to the first glass sheet 11 and the second glass sheet 12. In other words, the use of the optical element 32 can be omitted. Furthermore, when the light source 31 is provided on the side surface of the second glass sheet 12, there is no need to provide a member such as a light source on the side of the fourth main surface 24 of the second glass sheet 12 (the side facing the vehicle interior), which makes it possible to increase the interior space of the vehicle.

[0074] The vehicle window glass 1j shown in Fig. 12 has a band-shaped shielding region 53 on the edge side of the first glass plate 11 in a plan view of the first glass plate 11. In this case, the first region 51 is provided between the shielding region 53 and the second region 52. In the shielding region 53, the first glass plate 11 has a first shielding layer 41 on the second main surface 22. In the shielding region 53, the second glass plate 12 has a second shielding layer 42 on the fourth main surface 24. As shown in Fig. 6, the width of the second shielding layer 42 (the length in the left-right direction on the page) may be shorter than the width of the first shielding layer 41. The light source 31 is arranged at a position that does not overlap with the second shielding layer 42 in a plan view of the second glass plate 12.

[0075] 12, the vehicle window glass 1j is provided with the first shielding layer 41 and the second shielding layer 42, thereby reducing light leakage from the light source 31. That is, it is possible to prevent light from the light source 31 from directly leaking outside the vehicle compartment. In addition, it is possible to prevent sunlight from directly irradiating the light source 31 from outside the vehicle compartment, thereby improving the durability of the light source 31.

[0076] The vehicle window glass 1k shown in Fig. 13 has a band-shaped shielding region 53 on the edge side of the first glass plate 11 in a plan view of the first glass plate 11. In this case, the first region 51 is provided between the shielding region 53 and the second region 52. In the configuration example shown in Fig. 13, a colored intermediate adhesive layer (second colored layer) 45 is provided in the shielding region 53. The colored intermediate adhesive layer 45 may be made of the same material as the colored intermediate adhesive layer 14. The light source 31 is arranged in a position that does not overlap with the colored intermediate adhesive layer 45 in a plan view of the first glass plate 11.

[0077] 13, the provision of the colored intermediate adhesive layer 45 can reduce light leakage from the light source 31. That is, it is possible to prevent light from the light source 31 from directly leaking outside the vehicle compartment. In addition, it is possible to prevent sunlight from directly irradiating the light source 31 from outside the vehicle compartment, thereby improving the durability of the light source 31.

[0078] In this embodiment, in the configuration example shown in Figures 8 and 9, by omitting the light scattering means 17 on the second glass plate 12 side, it is possible to configure the light incident from the light source 31 to be extracted only to the outside of the vehicle compartment.

[0079] The present invention has been described above in accordance with the above-mentioned embodiment, but the present invention is not limited to the configuration of the above-mentioned embodiment, and naturally includes various modifications, alterations, and combinations that a person skilled in the art can make within the scope of the invention as defined in the claims of this application.

[0080] This application claims priority based on Japanese Patent Application No. 2023-206312, filed December 6, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0081] REFERENCE SIGNS LIST 1, 1a to 1k Vehicle window glass 11 First glass plate 12 Second glass plate 13, 14, 18 Intermediate adhesive layer 15 Low refractive index layer 16, 17 Light scattering means 19 Low refractive index coating 21 First main surface 22 Second main surface 23 Third main surface 24 Fourth main surface 31 Light source 32 Optical element 33, 34 Light 41 First shielding layer 42 Second shielding layer 43 Third shielding layer 45 Intermediate adhesive layer 51 First region 52 Second region 53 Shielding region

Claims

1. A vehicle window glass comprising: a first glass plate having a first principal surface and a second principal surface; a second glass plate having a third principal surface and a fourth principal surface; an intermediate adhesive layer disposed between the first glass plate and the second glass plate; a light source that causes light to be incident on at least one of the second glass plate and the intermediate adhesive layer; and light scattering means configured to be able to extract the light incident from the light source to the outside from the first principal surface, wherein the second principal surface and the third principal surface face each other, the first glass plate is disposed on the outside of a vehicle and the second glass plate is disposed on the inside of the vehicle, and the light incident from the light source is configured to be wave-guided through the first glass plate after passing through at least one of the second glass plate and the intermediate adhesive layer, wherein, in a plan view of the first glass plate, a region located on an edge side of the first glass plate is defined as a first region and a region located closer to the center than the first region is defined as a second region, and a visible light transmittance of the first region is greater than a visible light transmittance of the second region.

2. A vehicle glazing as claimed in claim 1, wherein in said second region, said intermediate adhesive layer comprises a first tint layer.

3. The vehicle window glass according to claim 2, further comprising a low refractive index layer between the first glass plate and the first colored layer.

4. The vehicle window glass according to claim 3, wherein the refractive index of the low refractive index layer is 1.45 or less.

5. The vehicle window glass according to claim 3, wherein the low refractive index layer contains a fluororesin.

6. A vehicle window glass according to claim 3, wherein the light scattering means is provided between the first glass plate and the low refractive index layer.

7. A vehicle window glass according to claim 3, wherein the light scattering means is provided between the first glass plate and the low refractive index layer, and between the second glass plate and the first colored layer.

8. A vehicle window glass as described in claim 1, wherein, in a plan view of the first glass plate, a band-shaped shielding region is provided on an end side of the first glass plate, and the first region is provided between the shielding region and the second region.

9. A vehicle glazing as claimed in claim 8, wherein in the shielding region, the first glass sheet has a first shielding layer on the second main surface.

10. A vehicle glazing as claimed in claim 8, wherein in the occlusion region, the intermediate adhesive layer comprises a second tinted layer.

11. A vehicle window glass as described in claim 8, wherein in the shielding region, the second glass plate has a second shielding layer on the fourth main surface, and when viewed in a plan view of the second glass plate, the light source is arranged in a position that does not overlap with the second shielding layer.

12. A vehicle window glass according to any one of claims 8 to 11, wherein, in a plan view of the second glass plate, the second glass plate has a third shielding layer in a region including the boundary between the first region and the second region of the fourth main surface.

13. A vehicle window glass according to claim 1 or 2, wherein the light source causes light to be incident on the fourth main surface of the second glass plate.

14. The vehicle window glass according to claim 1 or 2, wherein the visible light transmittance of the first region is 70% or more.

15. The vehicle window glass according to claim 1 or 2, wherein the visible light transmittance of the second region is 20% or less.

16. A vehicle window glass as claimed in claim 1 or 2, wherein the visible light transmittance of the first glass plate is equal to or greater than the visible light transmittance of the second glass plate.

17. A vehicle window glass as claimed in claim 1 or 2, wherein an optical element is provided on the fourth main surface to allow irradiation light from the light source to be incident on the fourth main surface of the second glass plate, and when the distance between the end of the optical element on the side where light is introduced from the light source and the end of the optical element on the second region side is d, the relationship 0 mm < d < 120 mm is satisfied.

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