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 Young's modulus of the longitudinal end of the optical member is E1, and the Young's modulus of the central part in the longitudinal direction, which is further from the end, is E0.

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, a configuration is known in which light from the light source is guided into the glass, scattered, and emitted from the main surface of the glass.

[0003] For example, Patent Document 1 discloses a vehicle window glass including a window glass main body assembly having an outer window glass main body 16 and an inner window glass main body 18, and a light source 24 configured to couple light into the inner window glass main body 18 that serves as a light guide layer, wherein it is described that 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 surface of the window glass main body assembly via an adhesive layer 30 (adhesive agent layer). [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese National Publication of International Patent Application No. 2023-520153 [Summary of the Invention] [Problem to be Solved by the 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 and 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 emission from the window glass may not be achieved.

[0006] Accordingly, an aspect of the present disclosure provides a technique 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: a 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 that scatters the light, provided inside the laminated glass or on the fourth main surface, wherein when the Young's modulus at a longitudinal end of the optical member is E1, and the Young's modulus at a central portion closer to the longitudinal center than the end is E0, the condition E1 < E0 is satisfied. [Effects of the Invention]

[0008] According to one aspect of the present disclosure, even when the optical member bonded via the 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] It is a plan view of an example of a window glass according to an embodiment of the present disclosure. [Figure 2] It is a cross-sectional view taken along line I-I of Figure 1. [Figure 3] It is a cross-sectional view taken along line II-II of the figure. [Figure 4] It is an enlarged view of portion III of Figure 3. [Figure 5] It is a view corresponding to Figure 4 of a window glass according to a modification. [Figure 6] It is a view corresponding to Figure 4 of a window glass according to another 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, identical or corresponding components 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] As for the exterior glass plate 11 and the interior glass plate 12 (hereinafter collectively simply referred to as glass plates), inorganic glass is preferable. Examples of the inorganic glass include soda lime silicate glass, aluminosilicate glass, borate glass, lithium aluminosilicate glass, and borosilicate glass. There is no particular limitation on the method for forming a glass plate made of inorganic glass, but it is preferable that the glass plate is formed by, for example, a float process. Further, the glass plate may be tempered glass or untempered glass.

[0018] The exterior glass plate 11 and the interior glass plate 12 may have the same thickness or different thicknesses from each other. The thickness of the exterior glass plate 11 may be 1.1 mm or more and 3.5 mm or less. Further, the thickness of the interior 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 is no particular limitation on the material constituting the interlayer film 13 disposed between the second main surface F2 of the exterior glass plate 11 and the third main surface F3 of the interior glass plate 12, but a thermoplastic resin is preferable. The material of the interlayer film 13 may be a thermoplastic resin conventionally used for this application, and examples include plasticized polyvinyl acetal resins, plasticized polyvinyl chloride resins, saturated polyester resins, plasticized saturated polyester resins, polyurethane resins, plasticized polyurethane 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 term "plasticized" means that the resin is plasticized by the 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 that can scatter 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. A portion of the light introduced to the glass plate 12 is scattered by the scattering layer 15 and is brought 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 in the figures 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 roughening the surface of the glass plate 11 by lithography or chemical etching of the glass plate 12, 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 are 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 the lights can be adjusted arbitrarily, 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] Furthermore, the thickness of the optical element 30 (length in the z-direction in the drawing) may preferably be 1 mm or more and 5 mm or less. If the thickness of the optical element 30 is not uniform in the longitudinal direction (as described later), the above thickness shall be the thickness of the central part 32.

[0038] 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.

[0039] 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 1.53. 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 component 30 may be different, but it is preferable that they be the same.

[0040] 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.

[0041] 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 one or more 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.

[0042] 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 illumination 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 illumination device that illuminates the inside of the automobile, for example, as an electric illumination device, or as a display device that can be seen by the occupants of the automobile.

[0043] <Configuration of optical components> As described with reference to FIGS. 1 to 3, in the window glass 100 according to the present embodiment, the elongated optical member 30 is adhered to the main surface of the laminated glass 10 via the adhesive layer 40. In actual use, the window glass 100 is often exposed to environments with large temperature changes. In such environments, the optical member 30 is prone to volume changes due to heat, specifically, expansion and / or contraction caused by heat. However, the adhesive layer 40 cannot sufficiently follow the volume change of the optical member 30, and peeling may occur between the optical member 30 and the adhesive layer 40, or between the adhesive layer 40 and the glass plate, or fracture may occur within the adhesive layer 40. In any case, a peeling phenomenon occurs between the optical member 30 and the laminated glass 10. When such a peeling phenomenon occurs, the 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 function and display function provided by the window glass 100 cannot be sufficiently obtained. In particular, when the optical member 30 is elongated, the influence of volume change is likely to appear at the end portions in the longitudinal direction, so the above-described peeling phenomenon is likely to occur at the end portion 31 (FIG. 3) of the optical member 30.

[0044] In contrast, in one embodiment of the present disclosure, the configuration of the elongated optical member 30 is not made entirely uniform, but the configuration of a part of the optical member 30, more specifically, the end portion 31 in the longitudinal direction (y-direction in the drawings) of the elongated optical member 30 is changed. Here, FIG. 4 also shows an enlarged view of part III in FIG. 3.

[0045] In the present embodiment, the elastic modulus (one or more of Young's modulus, bulk modulus, modulus of rigidity, and Poisson's ratio) differs between the longitudinal end portion 31 of the optical member 30 and the longitudinal central portion 32 of the optical member 30. At least, the Young's modulus E1 of the longitudinal end portion 31 of the optical member 30 is set to be smaller than the Young's modulus E0 of the longitudinal central portion 32 of the optical member 30 (that is, E1 < E0). In the example shown in FIG. 4, materials having different Young's moduli are used for the longitudinal end portion 31 of the optical member 30 and the longitudinal central portion 32 of the optical member 30.

[0046] In this specification, the longitudinal end portion 31 of the optical member 30 may be the portion from the end face (edge) of the optical member 30 to a position that is 1 / 25 or less of the longitudinal length L of the optical member 30 (L / 25 or less). That is, the length of the end portion 31 shown in Figure 3 may be Le = L / 25. The region of the optical member 30 other than both ends 31, 31, i.e., the region in the longitudinal direction centered above both ends 31, 31, is defined as the central portion 32. Furthermore, the end portion 31 may be the portion from the end face of the optical member to a position 5 mm or less in the longitudinal direction. That is, the length of the end portion 31 shown in Figure 3 may be Le ≤ 5 mm.

[0047] In this way, by making the Young's modulus E1 of the end portion 31 smaller than the Young's modulus E0 of the central portion 32, the end portion 31 becomes more flexible. In other words, even if volume changes (expansion and / or contraction) occur in the end portion 31 due to the effects of heat, the material itself can be easily deformed, so the adhesive surface at the end portion 31 of the optical member 30 can be maintained in a state where it is held to the glass via the adhesive layer 40. This suppresses or prevents the aforementioned delamination phenomenon between the optical member 30 and the laminated glass.

[0048] Furthermore, through diligent research by the inventors, they discovered a location where stress is likely to occur when glass and a component (optical component) with different coefficients of thermal expansion are bonded together via an adhesive layer and placed in an environment with temperature changes. According to the above, the location where stress is likely to occur depends on the material, shape, and thickness of the optical component, but it was found to be near a position of L / 500 to L / 25 in the longitudinal direction from the edge of the optical component 30. Therefore, by making the portion of the optical component 30 whose structure is changed the portion up to L / 25 or less from the longitudinal edge of the optical component 30, the volume change in the portion of the optical component 30 that is prone to delamination is reduced, and delamination between the optical component 30 and the glass can be effectively prevented. In addition, since the length of the central portion 32 can be ensured to be longer, the desired function of the optical component 30 is also maintained.

[0049] The Young's moduli of the end portions 31 and the central portion 32 can be obtained by cutting out the end portions 31 and the central portion 32 of the optical member 30 in the window glass 100 respectively, and for each portion, for example, applying a tensile load to a generally rod-shaped or plate-shaped test piece in a tensile test and determining the displacement thereof, thereby calculating the Young's modulus. The displacement can be measured with a strain gauge or a laser displacement meter.

[0050] The relationship between the Young's modulus E0 of the central portion 32 and the Young's modulus E1 of the end portions 31 (E1 < E0) only needs to be satisfied in at least one end portion 31 of the optical member 30. However, it is preferable that the relationship is satisfied in both end portions 31, 31, because the peeling phenomenon can be more reliably suppressed.

[0051] The Young's modulus E0 of the central portion 32 of the optical member 30 may preferably be 1.0 GPa or more and 20 GPa or less, more preferably 1.5 GPa or more and 15 GPa or less, still more preferably 2 GPa or more and 10 GPa or less. Further, the Young's modulus E1 of the end portions 31 of the optical member 30 may preferably be 0.01 GPa or more and 2 GPa or less, more preferably 0.05 GPa or more and 1 GPa or less, still more preferably 0.1 GPa or more and 0.5 GPa or less. When the Young's modulus E1 is within the above range, the effect of suppressing the peeling phenomenon at the end portions 31 of the optical member 30 described above can be improved, the light guiding function of the optical member 30 at the end portions 31 is not hindered, and the robustness of the end portions 31 can also be ensured.

[0052] In the present embodiment, the configuration of the optical member 30 for making the Young's modulus E1 of the end portions 31 smaller than the Young's modulus E0 of the central portion 32 is not particularly limited. For example, the end portions 31 and the central portion 32 may be formed of different materials respectively, and the two may be bonded in the longitudinal direction. Further, when molding the optical member 30, the resin R0 may be used as the material for the central portion 32 and the resin R1 may be used as the material for the end portions 31, and the optical member 30 may be integrally molded. When the optical member 30 is produced by injection molding or extrusion molding, the central portion 32 and the end portions 31 may be formed by multi-color molding.

[0053] When different materials are used for the central portion 32 and the end portion 31 of the optical component 30, the type of resin may be changed for the central portion 32 and the end portion 31, or the amount related to the elastic properties, such as the molecular weight of the resin, may be changed. Also, if the central portion 32 and the end portion 31 are copolymers, the monomer ratio of the two may be changed, or if they are polymer blends, the blend ratio of the two may be changed. The amount and / or type of additives in the material may also be changed for the central portion 32 and the end portion 31. For example, the resin R0 of the central portion 32 may be acrylic resin, and the resin R1 of the end portion 31 may be softened acrylic resin.

[0054] In this embodiment, the Young's modulus E0 in the central portion 32 and the Young's modulus E1 in the end portion 31 of the optical member 30 may be uniform. However, if the Young's modulus E0 in the central portion 32 and the Young's modulus E1 in the end portion 31 differ depending on the location, the Young's modulus E0 in the central portion 32 and the Young's modulus E1 in the end portion 31 shall be the average value within each respective portion.

[0055] Furthermore, the refractive index of light with a wavelength of 535 nm at the end portion 31 may be smaller than the refractive index of light with a wavelength of 535 nm at the central portion 32. 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 at the end portion 31 and the refractive index at the central portion 32 with respect to light with a wavelength of 535 nm be 0.02 or less.

[0056] 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.

[0057] The coefficient of linear expansion of the optical element 30 is 1.0 * 10 -5 / K or more 3.0*10-4 / K or lower. The coefficient of linear expansion of the vehicle interior glass plate 12 may be 5*10 -6 / K or higher and 1.0*10 -5 / K or lower.

[0058] Furthermore, for visible light, for example light with a wavelength of 535 nm, the transmittance at the end portion 31 may be lower than the transmittance at the central portion 32. This allows a difference in color to be recognized when visually checking the end portion 31 and the central portion 32. Consequently, the position of the end portion 31 can be recognized in the transparent optical member 30, which makes the optical member 30 easier to handle in the manufacturing process.

[0059] <Modified Example> 5 and 6 show modified examples of the window glass 100. The example shown in FIGS. 5 and 6 also satisfies the relationship that the Young's modulus E1 of the end portion 31 of the optical member 30 is smaller than the Young's modulus E0 of the central portion 32 (E1<E0), similarly to the configuration described above. However, in the example shown in FIG. 5, although the entire optical member 30 is formed of a single same material, the end portion 31 is subjected to a treatment that reduces the Young's modulus compared to that of the original material. Such treatment may be, for example, treatment such as immersion in a chemical or ultrasonic processing before bonding the optical member 30 to glass.

[0060] Furthermore, in the example shown in FIG. 6, similarly to the example shown in FIG. 4, materials with different Young's moduli are used for the central portion 32 and the end portion 31, and furthermore, the thickness h1 of the end portion 31 is smaller than the thickness h0 of the central portion 32. Reducing the thickness h1 of the end portion 31 compared to the thickness of the central portion 32 reduces the volume of the end portion 31, so the volume change (expansion and / or contraction) of the end portion 31 when affected by heat is also reduced, thereby further increasing the effect of suppressing peeling between the optical member 30 and the laminated glass 10.

[0061] As in the example shown in FIG. 6, when the thickness h1 of the end portion 31 of the optical member 30 is smaller than the thickness h0 of the central portion 32, the thickness h1 of the end portion 31 may preferably be 0.1 mm or more and 4 mm or less.

[0062] <Method for producing window glass> An embodiment of the present disclosure may be the method for producing window glass described above. For example, a method for producing window glass according to an embodiment comprises: preparing laminated glass including an exterior glass sheet having a first main surface and a second main surface, an interior glass sheet 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; and attaching the light source to an elongated optical member that guides light from the light source into the laminated glass by adhering the elongated optical member to the fourth main surface via an adhesive layer, wherein a light scattering layer that scatters the light is provided inside the laminated glass or on the fourth main surface, and when the Young's modulus at a longitudinal end portion of the optical member is defined as E1, and the Young's modulus at a central portion closer to the longitudinal center than the end portion is defined as E0, the condition E1<E0 is satisfied. The method may be a method for producing window glass that satisfies the above condition.

[0063] While the present disclosure has been described based on the embodiments above, 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 all such variations also fall within the technical scope of the present disclosure. Description of Reference Numerals

[0064] 10 Laminated glass 11 Exterior glass sheet 12 Interior glass sheet 13 Intermediate film 15 Light scattering layer 18 Shielding layer 20 Light source 30 Optical member 31 End portion of optical member 32 Central portion of optical member 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 having a Young's modulus E1 at the longitudinal end of the optical member, and a Young's modulus E0 at the central part of the longitudinal center of the optical member, such that E1 < E0.

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 E1 is 0.01 GPa or more and 2 GPa or less, and E0 is 1.0 GPa or more and 20 GPa or less.

9. The window glass according to claim 7, wherein the end portion and the central portion are integrally molded from different materials.

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.

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