window glass

Abstract

This technology provides an optical component bonded via an adhesive layer that prevents delamination between the optical component and the glass, even in environments with large temperature fluctuations. [Solution] The window glass comprises a laminated glass having an outer glass plate having a first main surface and a second main surface, an inner glass plate having a third main surface and a fourth main surface, and an interlayer disposed between the second main surface and the third main surface; a light source; a long optical member bonded to the fourth main surface via an adhesive layer for guiding light from the light source to the laminated glass; and a light scattering layer provided in the laminated glass or on the fourth main surface for scattering the light, wherein the thickness of the end of the optical member in the longitudinal direction is h1, and the thickness of the central part in the longitudinal direction from the end is h0,

Description

[[Technical Field]]

[0001] The present disclosure relates to window glass. [[Background Art]]

[0002] As a window glass including a plate-shaped glass and a light source, there is known a configuration in which light from the light source is guided into the glass, scattered, and radiated from the main surface of the glass.

[0003] For example, Patent Document 1 discloses a vehicle window glass including a window glass body assembly having an outer window glass body 16 and an inner window glass body 18, and a light source 24 configured to couple light into the inner window glass body 18 that is a light guide layer, wherein a rod-shaped input coupling element 28 that couples light from the light source 24 to the light guide layer is fixed to the inner side surface of the window glass body assembly via an adhesive layer 30 (adhesive agent layer). [[Prior Art Literature]] [[Patent Literature]]

[0004] [[Patent Document 1]] Japanese National Publication No. 2023-520153 [[Summary of Invention]] [[Problem to be Solved by Invention]]

[0005] When a window glass having the configuration described in Patent Document 1 is used in an environment with large temperature changes, the adhesive layer that bonds the optical member to the glass cannot follow the volume change (expansion and / or contraction) of the optical member, and peeling may occur between the optical member and the glass plate. If peeling occurs, light from the light source cannot be properly guided into the glass, and desired radiation from the window glass may not be achieved.

[0006] Therefore, an aspect of the present disclosure provides a technology capable of preventing peeling between an optical member and glass even when the optical member bonded via an adhesive layer is exposed to an environment with large temperature changes. [[Means for Solving the Problem]]

[0007] One aspect of the present disclosure is a window glass comprising: laminated glass having an exterior glass plate having a first main surface and a second main surface, an interior glass plate having a third main surface and a fourth main surface, and an intermediate film disposed between the second main surface and the third main surface; a light source; an elongated optical member that guides light from the light source to the laminated glass and is bonded to the fourth main surface via an adhesive layer; and a light scattering layer provided in the laminated glass or on the fourth main surface for scattering the light, wherein when h1 is the thickness of a longitudinal end portion of the optical coupling member, and h0 is the thickness of a central portion closer to the longitudinal center than the end portion, the condition h1 < h0 is satisfied. [[Advantageous Effects of Invention]]

[0008] According to one aspect of the present disclosure, even when an optical member bonded via an adhesive layer is exposed to an environment with large temperature changes, peeling between the optical member and the glass can be prevented. [[Brief Description of Drawings]]

[0009] [Figure 1] FIG. 1 is a plan view of an example of a window glass according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view taken along line I-I of FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view taken along line II-II of the figure. [Figure 4] FIG. 4 is an enlarged view of portion III in FIG. 3. [Figure 5] FIG. 5 is a view corresponding to FIG. 4 of a window glass according to a modification. [[Mode for Carrying Out the Invention]]

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding configurations are denoted by the same reference numerals, and description thereof may be omitted.

[0011] <Window Glass> Figure 1 shows a plan view of a window glass 100 according to one embodiment of the present disclosure. The use of the window glass of the present disclosure is not limited and may be for vehicles such as automobiles and trains or for building applications, but Figure 1 shows a window glass 100 for automobiles as an example. Figure 1 is a view of the window glass 100 for automobiles as seen from the inside of the vehicle. Figure 2 shows a cross-sectional view of line II in Figure 1, and Figure 3 shows a cross-sectional view of line II-II in Figure 2.

[0012] The window glass 100 according to this embodiment may be a roof glass, windshield, side glass, rear glass, etc., but the window glass 100 is preferably used as a roof glass.

[0013] For explanatory purposes, the drawings show coordinate axes including mutually perpendicular x, y, and z directions. Along the main surface of the window glass 100, the longitudinal direction of the window glass 100 is the y direction, the transverse direction is the x direction, and the thickness direction of the window glass 100 is the z direction. If the window glass 100 is a roof glass, the direction from the rear to the front of the vehicle when installed is the +y direction, the direction from left to right when viewed from the front of the vehicle is the +x direction, and the direction from the outside to the inside of the window glass 100 is the +z direction.

[0014] As shown in Figures 1 and 2, the window glass 100 comprises a glass 10, a light source 20, and an optical member 30 that guides light from the light source to the glass 10 and is bonded to one main surface of the glass 10 via an adhesive layer 40.

[0015] As shown in Figures 2 and 3, the glass 10 may be laminated glass. The laminated glass 10 includes an outer glass plate 11 having a first main surface F1 and a second main surface F2, an inner glass plate 12 having a third main surface F3 and a fourth main surface F4, and an interlayer 13 disposed between the second main surface F2 and the third main surface F3.

[0016] The configuration of the exterior glass panel 11 and the interior glass panel 12 (including the type or composition of the glass, thickness, manufacturing method, etc.) may be the same or different from each other.

[0017] Inorganic glass is preferable as the outer glass plate 11 and the inner glass plate 12 (hereinafter, collectively referred to simply as glass plates). Examples of the inorganic glass include soda lime silicate glass, aluminosilicate glass, borate glass, lithium aluminosilicate glass, and borosilicate glass. There are no particular limitations on the method for forming a glass plate made of inorganic glass, but the glass plate is preferably formed by, for example, a float process. Further, the glass plate may be either tempered glass or untempered glass.

[0018] The thicknesses of the outer glass plate 11 and the inner glass plate 12 may be the same or different from each other. The thickness of the outer glass plate 11 may be 1.1 mm or more and 3.5 mm or less. Further, the thickness of the inner glass plate 12 may be 0.5 mm or more and 2.3 mm or less. Furthermore, the total thickness of the laminated glass 10 can be 2.3 mm or more and 8.0 mm or less.

[0019] There are no particular limitations on the material constituting the interlayer film 13 disposed between the second main surface F2 of the outer glass plate 11 and the third main surface F3 of the inner glass plate 12, but a thermoplastic resin is preferable. As the material for the interlayer film 13, any thermoplastic resin conventionally used for this application may be used, and examples thereof include plasticized polyvinyl acetal-based resins, plasticized polyvinyl chloride-based resins, saturated polyester-based resins, plasticized saturated polyester-based resins, polyurethane-based resins, plasticized polyurethane-based resins, ethylene-vinyl acetate copolymer resins, ethylene-ethyl acrylate copolymer resins, cycloolefin polymer resins, and ionomer resins. These thermoplastic resins may be used alone or in combination of two or more. Among the above, plasticized polyvinyl acetal resins, particularly polyvinyl butyral resin (PVB), are suitably used. Note that the above "plasticized" means that the resin is plasticized by addition of a plasticizer.

[0020] The shape of the laminated glass 10, or the shapes of the outer glass plate 11 and inner glass plate 12 included in the laminated glass, is rectangular in the example shown in Figure 1, but is not limited to this shape and may be processed into various shapes. Furthermore, the laminated glass 10 may be curved so as to be convex on the outside of the vehicle. In this case, during the manufacturing process of the laminated glass 10, the outer glass plate 11 and inner glass plate 12 can be bent in one direction or two directions to a desired predetermined curvature by bending.

[0021] The laminated glass 10 may include a light-scattering layer 15 made of a material that has the function of scattering light introduced into the laminated glass 10. The presence of the light-scattering layer 15 in the laminated glass 10 allows the introduced light to be scattered by the light-scattering layer 15 and emitted from the main surface of the window glass 100.

[0022] In the examples shown in Figures 2 and 3, the light scattering layer 15 is a pattern that scatters light. That is, light introduced from the light source 20 to the optical member 30 is introduced to the glass plate 12 via the optical member 30. Then, a portion of the light introduced to the glass plate 12 is scattered by the scattering layer 15 and taken out to the outside of the glass plate 12, i.e., into the vehicle. The arrangement of the light scattering layer 15 is not limited to that shown, and may be provided at any position on the main surface or inside of the laminated glass 10. For example, the light scattering layer 15 may be located on the fourth main surface F4. However, in that case, it is preferable that the light scattering layer 15 is not present in the area where the optical member 30 is located, i.e., in the area where the adhesive layer 40 is located.

[0023] The light scattering layer 15 may extend over the entire surface direction (xy plane direction) of the window glass 100, but as shown in Figures 2 and 3, it may be formed discontinuously scattered across the entire window glass 100 in the surface direction. For example, the light scattering layer 15 may be formed in advance by printing on one or both surfaces of the interlayer 13 in a predetermined discontinuous pattern before the laminated glass 10 is manufactured. Alternatively, the light scattering layer 15 may be formed by printing on the fourth main surface F4. It can also be formed by physically etching or chemically etching the glass plate 12 to roughen the surface of the glass plate 11, or by printing a scattering material containing inorganic or organic fine particles onto the surface of the glass plate. As the light scattering layer 15, a layer with irregularities that enable light scattering formed on the main surface of a layer extending over the entire surface direction may be inserted into the laminated glass 10. The scattering layer can be set in various positions, but since the light guide in this configuration is the glass plate 12, it is desirable to set the scattering layer at a position in contact with the glass plate 12.

[0024] As shown in Figure 1, the laminated glass 10 may be provided with a shielding layer 18 to protect the sealant, etc., that adheres and holds the window glass 100 to the vehicle body. The shielding layer 18 will not be shown in the cross-sectional views from Figure 2 onward. The shielding layer 18 can be formed, for example, by applying a low-luminosity ceramic color paste, such as black, gray, or brownish-red, containing a fusible glass frit containing a black pigment, and firing it. The shielding layer 18 may be formed on one or more peripheries of the second main surface F2, third main surface F3, and fourth main surface F4 of the laminated glass 10, preferably on at least one periphery of the second main surface F2 and the fourth main surface F4, for example, on the periphery of the second main surface F2. By forming the shielding layer 18 on the second main surface F2, it is possible to prevent light from leaking out of the vehicle from the optical member 30. The shielding layer 18 may be provided in the peripheral region of the laminated glass 10, extending from the peripheral edge (from the end face) for a period of 10 mm to 500 mm. Furthermore, when a single laminated glass is installed across multiple openings in the vehicle body, the shielding layer 18 may also be provided in a strip-like shape extending in the x-direction, for example, as shown in Figure 1, in a portion of the main region, which is the area inside the peripheral region of the laminated glass 10, corresponding to the portion where the vehicle body frame extends. When the shielding layer 18 is set on the same plane as the optical member 30, it is provided avoiding the area where the optical member 30 is located, i.e., the area where the adhesive layer 40 is located.

[0025] The light source 20 used in this embodiment has, for example, an LED (Light Emitting Diode). The LED is, for example, a white LED. The white LED may be (A) a combination of a blue LED and a yellow phosphor, or (B) a combination of a blue LED, a green LED, and a red LED. When the light source 20 is a white LED, the correlated color temperature of the white LED is preferably 3000K to 5000K. The correlated color temperature of the light source 20 is measured in accordance with JIS Z8725:2015.

[0026] As described above, the light source 20 may have only one LED that emits light of a specific color, or it may have multiple LEDs that emit light of different colors. The multiple LEDs may be mounted on a PCB substrate or a flexible substrate, for example, and arranged at intervals along the periphery of the light guide layer 21. In that case, the light source 20 may be, for example, a long member (LED light bar) in which multiple LEDs are arranged in a straight line and the entire structure is sealed with resin. The resin used for sealing may include acrylic resin (PMMA), polycarbonate resin (PC), etc. By using multiple full-color LEDs, the position and color of illumination can be arbitrarily adjusted, increasing the freedom of design. Note that the LEDs may include OLEDs (Organic Light Emitting Diodes). In addition, the light source 20 may have a semiconductor laser (LD: Laser Diode) instead of LEDs.

[0027] The light source 20 may be located near the peripheral edge of the window glass 100, more specifically, along the edge of the plan view shape of the window glass 100. In the example shown in Figure 1, the light sources 20 are provided in the regions at both ends in the x-direction. In the example shown in Figure 1, two light sources 20 are provided at each end in the x-direction for one window glass 100, separated in the y-direction. However, the arrangement and number of light sources 20 can be appropriately determined according to the size of the window glass 100, the desired function, purpose, etc.

[0028] The optical member 30 is a member for guiding light from the light source 20 into the laminated glass 10, and is also called a prism. As shown in Figures 2 and 3, the optical member 30 is bonded to the main surface of the laminated glass 10, more specifically to the fourth main surface F4 of the laminated glass 10, via an adhesive layer 40. The presence of the optical member 30 allows the direction of light emitted from the light source 20 to be changed, enabling it to be properly guided into the laminated glass 10. The optical member 30 in this embodiment may be a member that transmits at least visible light. The refractive index of the optical member 30 is preferably 1.45 to 1.58, more preferably 1.48 to 1.55, and even more preferably 1.50 to 1.53 for light with a wavelength of 525 nm. The above refractive index is the refractive index at the central part 32 (described later) of the optical member 30.

[0029] Furthermore, it is preferable to use an optical element 30 having the following light transmittances when calculated per 1 mm thickness: The transmittance TvB for light with a wavelength of 467 nm is preferably 0.85 or higher, more preferably 0.90 or higher. The transmittance TvG for light with a wavelength of 532 nm is preferably 0.80, more preferably 0.85. The transmittance TvR for light with a wavelength of 630 nm is preferably 0.85, more preferably 0.90. The above light transmittances are the transmittances at the central part 32 (described later) of the optical element 30.

[0030] The optical component 30 may be made of resin, that is, a component made of a material mainly containing resin. Alternatively, the optical component 30 may be a resin molded body formed by extrusion molding, injection molding, etc. Examples of resins constituting the optical component 30 include acrylic resin (PMMA), polycarbonate resin (PC), polyamide resin (PA), cyclic olefin copolymer (COC), polystyrene (PS), and / or cycloolefin polymer (COP).

[0031] The optical element 30 is elongated. As shown in Figures 1 to 3, the optical element 30 is positioned on the window glass 100 such that its longitudinal direction aligns with the y-direction of the window glass 100. The aforementioned elongated light source 20 is positioned on the side of the optical element 30 closest to the peripheral edge of the window glass 100, such that the longitudinal direction of the light source 20 aligns with the longitudinal direction of the optical element 30. As shown in Figure 2, the light source 20 may be provided on the end face of the optical element 30 on the peripheral edge side of the window glass 100 by another support member (not shown). Alternatively, the light source 20 may be bonded to the optical element 30 using an adhesive or other bonding means, or it may be integrally molded together with the optical element 30.

[0032] Both the light source 20 and the optical element 30 are positioned on the fourth main surface F4 of the laminated glass 10. While it is possible to introduce light into the glass plate 12 by setting the light source on the edge of the glass plate 12, this presents challenges regarding the vehicle's watertightness and space. On the other hand, by providing the light source on the fourth main surface F4 of the glass plate 12 as in this configuration, the optical element can be laid out at any position within the glass surface, eliminating the need for a watertight structure.

[0033] As shown in Figure 2, the optical member 30 has a rectangular cross-section when cut by a plane perpendicular to the longitudinal direction, that is, it has the shape of a rectangular prism overall, but the shape of the optical member 30 is not limited to that shown. The shape of the optical member 30 is limited to the surface facing the fourth main surface F4 of the laminated glass 10 being a plane. For example, the shape of the cross-section of the optical member 30 when cut by a plane perpendicular to the longitudinal direction may be a polygon other than a quadrilateral, such as a triangle or pentagon, or it may be a partial circle or partial ellipse.

[0034] In this specification, "long" refers to a member whose length in one direction is sufficiently longer than its length in the direction perpendicular to that direction. Furthermore, a long member can be a rod-shaped, linear, strip-shaped, or any other shape. In this embodiment, the optical member 30 has a length in the y-direction in the drawing that is sufficiently longer than its length in the x-direction or z-direction. For example, the longitudinal length (y-direction length in the drawing) L of the optical member 30 may be 5 to 50 times its transverse length (x-direction length in the drawing).

[0035] The longitudinal length (y-direction length, also called the total length) L of one optical element 30 is determined according to the size, shape, etc. of the window glass 100, but is preferably 50 mm or more and 1000 mm or less, and more preferably 100 mm or more and 400 mm or less.

[0036] Furthermore, the length of one optical member 30 in the short direction (length in the x direction) is measured on the outer surface of the optical member 30, that is, the surface in contact with the adhesive layer 40 (hereinafter also referred to as the adhesive surface of the optical member 30), and is preferably 5 mm to 50 mm, more preferably 15 mm to 30 mm.

[0037] The adhesive layer 40 is not particularly limited as long as it can bond the surface of the glass plate to the optical member 30 described above and does not hinder the introduction of light from the optical member 30 into the glass interior 10. Preferably, the adhesive layer 40 is a transparent adhesive layer that transmits at least visible light. The refractive index of the adhesive layer 40 in the window glass 100 for light with a wavelength of 525 nm may be the same as the refractive index of the optical member 30 for light with the above wavelength. That is, the refractive index of the adhesive layer 40 in the window glass 100 for light with a wavelength of 525 nm may be preferably 1.45 or more and 1.58 or less, more preferably 1.48 or more and 1.55 or less, and even more preferably 1.50 or more and 1.54. Furthermore, both the refractive index of the adhesive layer 40 and the refractive index of the optical member 30 may be preferably 1.45 or more and 1.58 or less, more preferably 1.48 or more and 1.55 or less, and even more preferably 1.50 or more and 1.53. Furthermore, the refractive index of the adhesive layer 40 and the refractive index of the optical member 30 may be different, but it is preferable that they be the same or that the refractive index of the optical member 30 be higher than that of the adhesive layer 40.

[0038] Furthermore, it is preferable to use an adhesive for the adhesive layer 40 that has the following light transmittances when the thickness of the adhesive layer 40 is calculated at 100 μm: The transmittance TvB for light with a wavelength of 467 nm is preferably 0.85 or higher, more preferably 0.90 or higher. The transmittance TvG for light with a wavelength of 532 nm is preferably 0.80, more preferably 0.85. The transmittance TvR for light with a wavelength of 630 nm is preferably 0.85, more preferably 0.90.

[0039] The adhesive constituting the adhesive layer 40 may be a curing type adhesive that hardens with heat, light, etc., and a photocuring type adhesive that hardens with light such as ultraviolet light is preferred. The adhesive layer 40 may be a layer formed by applying a liquid adhesive, for example, a liquid optical transparent adhesive (LOCA). Specific types of adhesives include resin adhesives such as acrylate-based, silicone-based, urethane-based, urethane acrylate-based, epoxy-based, epoxy acrylate-based, acrylamide-based, and methacryamide-based adhesives. The adhesive layer 40 may also be formed by adhering a transparent resin adhesive sheet instead of using a liquid adhesive.

[0040] The thickness of the adhesive layer 40 on the window glass 100 (length in the z direction in the drawing) is preferably 50 μm or more and 1000 μm or less, more preferably 100 μm or more and 500 μm or less, and even more preferably 150 μm or more and 300 μm or less. The thickness of the adhesive layer 40 is the thickness at the central part 32 (described later) of the optical member 30.

[0041] In the window glass 100 according to this embodiment having the configuration described above, light introduced from the light source 20 to the optical member 30 is introduced into the laminated glass 10 through the adhesive layer 40, scattered by the light scattering layer 15 in the laminated glass 10, and emitted from the main surface of the laminated glass 10, preferably the surface on the inside of the vehicle. As a result, the window glass 100 can have an indirect lighting function that emits a predetermined light, or a display function that displays a predetermined image. When the window glass 100 is for an automobile, depending on the configuration of the light source 20 and the light scattering layer 15, it can function as an indirect lighting device that illuminates the inside of the vehicle, for example, as an electric lighting device to improve the design of the interior, or as a display device that can be seen by the occupants of the vehicle.

[0042] <Configuration of optical components> As explained with reference to Figures 1 to 3, in the window glass 100 according to this embodiment, a long optical member 30 is bonded to the main surface of the laminated glass 10 via an adhesive layer 40. In actual use, the window glass 100 is often exposed to environments with large temperature fluctuations. In such environments, the optical member 30 undergoes greater thermal volume changes than the glass plate 12, specifically thermal expansion and / or contraction, making it prone to stress due to volume differences. That is, the volume change of the optical member 30 is greater than that of the glass plate 12, and the adhesive layer 40 cannot keep up, causing stress to occur between the optical member 30 and the adhesive layer 40, or between the adhesive layer 40 and the glass plate, resulting in delamination, or fracture within the adhesive layer 40. In any case, delamination occurs between the optical member 30 and the laminated glass 10. When such delamination occurs, light incident on the optical member 30 from the light source 20 is not introduced into the laminated glass 10 via the adhesive layer 40, and the illumination and display functions of the window glass 100 cannot be fully obtained. In particular, when the optical member 30 is long, the effects of volume changes tend to appear at the ends in the longitudinal direction, so the above-mentioned delamination phenomenon is likely to occur at the end 31 (Figure 3) of the optical member 30.

[0043] In contrast, in one embodiment of the present disclosure, instead of making the configuration of the elongated optical member 30 entirely uniform, the configuration of a part of the optical member 30, more specifically, the end portion 31 of the elongated optical member 30 in the longitudinal direction (y-direction in the drawings) is changed. Here, Fig. 4 also shows an enlarged view of part III in Fig. 3.

[0044] As shown in Fig. 4, the thickness h1 of the longitudinal end portion 31 of the optical member 30 is smaller than the thickness h0 of the longitudinal central portion 32 of the optical member 30 (that is, h1 < h0). In the present specification, the longitudinal end portion 31 of the optical member 30 may be a portion from the position (end edge) of the end face of the optical member 30 to a position that is not more than 1 / 25 of the longitudinal length L of the optical member 30 (not more than L / 25). That is, the length Le of the end portion 31 shown in Fig. 3 may satisfy Le = L / 25. A region other than both end portions 31, 31 of the optical member 30, that is, a region that is more central in the longitudinal direction than both end portions 31, 31 is defined as the central portion 32. Further, the end portion 31 may be a portion from the end face of the optical member to a position of 50 mm or less in the longitudinal direction. That is, the length Le of the end portion 31 shown in Fig. 3 may satisfy Le ≤ 50 mm.

[0045] As described above, by making the thickness h1 of the end portion 31 smaller than the thickness h0 of the central portion 32, the volume of the end portion 31 is reduced, and volume change (expansion and / or contraction) at the end portion 31 when affected by heat is suppressed, so the above-described peeling phenomenon between the optical member 30 and the laminated glass can be suppressed or prevented.

[0046] Furthermore, as a result of intensive studies by the inventors, the inventors have found that when a member (optical member) having a linear expansion coefficient different from that of glass is bonded to glass via an adhesive layer and placed in an environment with temperature changes, stress is likely to occur. According to the above findings, although the location where stress is likely to occur depends on the material, shape and thickness of the optical member, it has been found that such location is near the position not less than L / 500 and not more than L / 25 in the longitudinal direction from the edge of the optical member 30. Therefore, by setting the portion (end portion) of the optical member 30 whose configuration is changed to be the portion from the longitudinal edge of the optical member 30 to a position of L / 25 or less, the volume change of the portion where peeling of the optical member 30 is likely to occur is reduced, and peeling between the optical member 30 and the glass can be effectively prevented. In addition, since a long length of the central portion 32 can be ensured, the desired function of the optical member 30 is also maintained.

[0047] The relationship between the thickness h0 of the central portion 32 and the thickness h1 of the end portion 31 (h1 < h0) described above only needs to be satisfied in at least one end portion 31 of the optical member 30, but it is preferable that the relationship is satisfied in both end portions 31, 31, because peeling can be suppressed more reliably.

[0048] The thickness h0 (the length in the z-direction in the drawings) of the central portion 32 of the optical member 30 may be preferably 1 mm or more and 5 mm or less, more preferably 1.5 mm or more and 4 mm or less, still more preferably 2 mm or more and 3 mm or less. Further, the thickness h1 of the end portion 31 of the optical member 30 may be preferably 0.1 mm or more and 4 mm or less, more preferably 0.3 mm or more and 3 mm or less, still more preferably 0.5 mm or more and 2 mm or less. When the thickness h1 is within the above range, the effect of suppressing the peeling phenomenon at the end portion 31 of the optical member 30 described above can be improved, the light guiding function of the optical member 30 is not hindered even at the end portion 31, and the robustness of the end portion 31 can also be ensured.

[0049] In the examples shown in FIGS. 1 to 4, the thickness h0 in the central portion 32 and the thickness h1 in the end portions 31 of the optical member 30 are each uniform, but the thickness h0 in the central portion 32 and the thickness h1 in the end portions 31 may differ depending on the location. In such a case, the thickness h0 of the central portion 32 and the thickness h1 of the end portions 31 are each an average value within each respective portion.

[0050] The refractive index difference between the adhesive layer and the glass plate at the end portion 31 for light with a wavelength of 535 nm may be greater than the refractive index difference between the adhesive layer and the glass plate at the central portion 32 for light with a wavelength of 535 nm. However, in order to minimize the difference in light-guiding function between the end portion 31 and the central portion 32, it is preferable that the difference between the refractive index difference between the glass plate and the adhesive layer at the end portion 31 and the refractive index difference at the central portion 32 for light with a wavelength of 535 nm be 0.02 or less.

[0051] The difference in the coefficient of linear expansion between the optical element 30 and the interior glass plate 12 is preferably 4.0*10 at room temperature. -4 / K or less, more preferably 1.0*10 -4 It may be less than or equal to / K. In this specification, "room temperature" is defined as 298K. The coefficient of linear expansion can be measured by thermomechanical analysis. By using a material with the above-described difference in the coefficient of linear expansion as the optical component 30, the delamination phenomenon between the optical component 30 and the laminated glass 10 can be further suppressed.

[0052] The coefficient of linear expansion of the optical element 30 is 1.0 * 10 -5 / K or more 3.0*10 -4 It may be less than or equal to / K. Also, the coefficient of linear expansion of the interior glass plate 12 is 5*10 -6 / K or more 1.0*10 -5 It may be less than or equal to / K.

[0053] <Variation> Figure 5 shows a modified example of the window glass 100.

[0054] In the example shown in Figure 4, the inner surface of the optical member 30, i.e., the surface opposite to the laminated glass 10, is flush with the central portion 32 and the end portion 31, while the outer surface of the optical member 30, i.e., the surface facing the laminated glass 10 (adhesive surface), has a step between the central portion 32 and the end portion 31. In this shape, the amount of adhesive layer at the end portion, which is prone to stress, is greater than at the central portion, resulting in higher stress-induced peel strength. In contrast, in the example shown in Figure 5(a), the inner surface of the optical member 30 has a step between the central portion 32 and the end portion 31, while the outer surface of the optical member 30 (adhesive surface) is flush with the central portion 32 and the end portion 31, resulting in a uniform thickness of the adhesive layer 40. This makes it possible to apply not only liquid adhesives but also film-type adhesives. Steps may be formed on both the outer and inner surfaces of the optical member 30.

[0055] Furthermore, as shown in Figures 5(b) to (d), the thickness of the end portion 31 may gradually change in the longitudinal direction. In such a case, the thickness h1 of the end portion 31 can be set to half the difference between the maximum and minimum thicknesses at the end portion 31.

[0056] In the examples shown in Figures 5(b) and (c), the thickness of the optical member 30 gradually decreases towards the longitudinal edge. As shown in Figure 5(a), if the adhesive surface includes corners, air bubbles are likely to form at the corners, but as shown in Figures 5(b) and (c), if the corners are eliminated, air bubbles are more likely to escape. In the example shown in Figure 5(b), the thickness at the edge of the optical member 30 is not zero, and it has an end face. In this case, the difference between the maximum and minimum thickness at the end 31 is not so large, and the difference in the amount of adhesive applied within the end 31 is small, which is preferable because it makes it less likely for the optical member to be bonded in an inclined state. Also, in the example shown in Figure 5(c), at the edge of the optical member 30, the adhesive layer 40 reaches the inner surface of the optical member 30. In this configuration, the volume of the end 31 can be made smaller, and the volume change of the end 31 can also be made smaller, which effectively suppresses the peeling phenomenon.

[0057] Furthermore, as shown in FIG. 5(d), since there is no step on the vehicle-interior side surface of the optical member 30, similar to the example shown in FIG. 5(a), a film-type adhesive can also be used, and there is an additional advantage that resin molding is easy.

[0058] Note that the shape of the optical member 30 is not limited to the above-described embodiment as long as the thickness h1 of the end portion 31 of the optical member 30 is smaller than the thickness h0 of the central portion, and the optical member 30 can be formed into various shapes.

[0059] <Method for Manufacturing Window Glass> Note that one embodiment of the present disclosure may be the method for manufacturing a window glass described above. For example, a method for manufacturing a window glass according to one embodiment includes: preparing a laminated glass having an exterior glass panel having a first main surface and a second main surface, an interior glass panel having a third main surface and a fourth main surface, and an interlayer film disposed between the second main surface and the third main surface; bonding a long optical member that guides light from a light source to the laminated glass to the fourth main surface via an adhesive layer; attaching the light source to the optical member; wherein a light scattering layer that scatters the light is provided in the laminated glass or on the fourth main surface, and when h1 is the thickness of a longitudinal end portion of the optical member and h0 is the thickness of a central portion in the longitudinal direction that is closer to the center than the end portion, the condition h1 < h0 is satisfied.

[0060] The present disclosure has been described above based on embodiments, but the present disclosure is not limited by these embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations can be made to the above-described embodiments within the scope of the claims, and these also belong to the technical scope of the present disclosure. [Description of Reference Signs]

[0061] 10 Laminated glass 11 Exterior glass panel 12 Interior glass panel 13 Interlayer film 15 Light scattering layer 18 Shielding layer 20 Light source 30 Optical member 31 End of optical component 32 Central part of the optical component 40 Adhesive layer 100 window glass

Claims

1. An exterior glass panel having a first main surface and a second main surface, An interior glass panel having a third main surface and a fourth main surface, Laminated glass having an interlayer disposed between the second main surface and the third main surface, Light source and A long optical member, bonded to the fourth main surface via an adhesive layer, guides light from the light source to the laminated glass, The laminated glass or the fourth main surface comprises a light scattering layer that scatters the light, A window glass in which the thickness of the optical element at its longitudinal end is h1, and the thickness of the central part of the optical element located in the longitudinal center of the optical element is h0, such that h1 < h0.

2. The window glass according to claim 1, wherein the end portion is the portion from the end face of the optical member to a position L / 25 or less in the longitudinal direction, where L is the length of the optical member in the longitudinal direction.

3. The window glass according to claim 1 or 2, wherein the end portion is the portion extending 50 mm or less in the longitudinal direction from the end face of the optical member.

4. The window glass according to claim 1 or 2, wherein the optical member is made of resin.

5. The difference in coefficient of linear expansion between the optical element and the interior glass plate is 4.0 * 10 at room temperature. －４ The window glass according to claim 1 or 2, wherein the temperature is less than or equal to / K.

6. The window glass according to claim 1 or 2, wherein the adhesive layer is made of a transparent adhesive.

7. The window glass according to claim 1 or 2, wherein the ends are both ends in the longitudinal direction of the optical member.

8. The window glass according to claim 1 or 2, wherein the volume per unit area of ​​the adhesive surface in contact with the adhesive layer at the end of the optical member is smaller than the volume per unit area of ​​the adhesive surface in contact with the adhesive layer at the central part.

9. The window glass according to claim 1 or 2, wherein the h1 is 0.1 mm or more and 4 mm or less, and the h0 is 1 mm or more and 5 mm or less.

10. The window glass according to claim 1 or 2, wherein the refractive index of light with a wavelength of 535 nm at the end portion is smaller than the refractive index of light with a wavelength of 535 nm at the central portion.

11. The window glass according to claim 10, wherein the refractive index of light with a wavelength of 535 nm in the central portion is 1.45 or more and 1.58 or less, and the refractive index of the adhesive layer with a wavelength of 535 nm is 1.45 or more and 1.58 or less.

Images