Laminated glass

Abstract

The present invention improves visibility of an HUD image in laminated glass having an anti-fogging means.　This laminated glass is provided with: a first glass plate; a second glass plate; and an intermediate film that is located between the first glass plate and the second glass plate, and that adheres the first glass plate and the second glass plate together. The laminated glass has: an optical reflective layer that reflects light entering through the first glass plate; a heating function layer that is disposed closer to the second glass plate as compared to the optical reflective layer in a cross-sectional view, and that has at least a portion thereof overlapping the optical reflective layer in plan view; and a first concealment layer that is disposed between the optical reflective layer and the heating function layer in a cross-sectional view, and that overlaps the heating function layer in a plan view.

Description

Laminated glass

[0001] The present invention relates to laminated glass.

[0002] In head-up displays (hereinafter also referred to as HUDs), there is a demand for improved visibility of the HUD image. Various technologies have been studied to achieve this demand. For example, the following patent document proposes a technology in which a laminated glass is provided with a heatable anti-fogging means to suppress a decrease in visibility of the HUD image due to freezing of moisture adhering to the laminated glass or fogging of the laminated glass caused by the temperature difference between the inside and outside of the vehicle in a low-temperature environment, etc.

[0003] International Publication No. 2022 / 238101

[0004] However, unless the defogging means is concealed so as not to be visible from inside the vehicle, the visibility of the HUD image may be reduced.

[0005] The present invention has been made in view of the above points, and has an object to improve the visibility of HUD images in laminated glass having an anti-fogging means.

[0006] A laminated glass according to one embodiment of the disclosure is a laminated glass comprising a first glass plate, a second glass plate, and an intermediate film located between the first glass plate and the second glass plate and bonding the first glass plate to the second glass plate, and further comprising: an optical reflective layer that reflects light incident from the first glass plate side; a heating function layer that is located closer to the second glass plate than the optical reflective layer in a cross-sectional view and at least a portion of which overlaps with the optical reflective layer in a planar view; and a first concealing layer that is located between the optical reflective layer and the heating function layer in a cross-sectional view and overlaps with the heating function layer in a planar view.

[0007] According to one embodiment of the disclosure, the visibility of HUD images in laminated glass having an anti-fogging means can be improved.

[0008] FIG. 1 is a schematic diagram illustrating a HUD system according to the first embodiment; FIG. 2A and FIG. 2B are diagrams illustrating laminated glass according to the first embodiment; FIG. 3 is a cross-sectional view illustrating laminated glass according to Modification 1 of the first embodiment; FIG. 4 is a cross-sectional view illustrating laminated glass according to Modification 2 of the first embodiment; FIG. 5A and FIG. 5B (part 1) are diagrams illustrating laminated glass according to Modification 3 of the first embodiment; FIG. 6A and FIG. 6B (part 2) are diagrams illustrating laminated glass according to Modification 3 of the first embodiment; FIG. 8A and FIG. 8B are diagrams illustrating laminated glass according to Modification 5 of the first embodiment; FIG. 9 is a diagram illustrating laminated glass according to Modification 6 of the first embodiment; and FIG. 10 is a diagram illustrating laminated glass according to Modification 7 of the first embodiment.

[0009] Hereinafter, the embodiments of the present invention will be described with reference to the drawings. In each drawing, the same components are designated by the same reference numerals, and duplicate explanations may be omitted. In each drawing, the size and shape may be partially exaggerated to make the contents of the present invention easier to understand.

[0010] The term "vehicle" refers to any moving body capable of mounting laminated glass, including, but not limited to, automobiles, trains, ships, and aircraft.

[0011] Furthermore, a planar view refers to viewing an object from the direction of a normal line passing through the center of gravity of the main surface of the object, and the shape seen in this case is referred to as a planar shape.

[0012] Furthermore, the terms "top" and "bottom" refer to the top and bottom of the laminated glass when it is installed in a vehicle.

[0013] Furthermore, the outermost edge of a given member is referred to as the "periphery," and an area of ​​the given member having a width that is inscribed in the "periphery" is referred to as the "periphery portion."

[0014] First Embodiment [HUD System] Fig. 1 is a schematic diagram illustrating a HUD system according to a first embodiment. The HUD system 1 shown in Fig. 1 includes a laminated glass 10, a light source 50, a first optical system 60, an image display element 70, a second optical system 80, and a concave mirror 90. The HUD system 1 is a head-up display system for a vehicle that displays a virtual image on the vehicle exterior side of the laminated glass 10. Note that in the HUD system 1, the first optical system 60 and the second optical system 80 may be provided as needed.

[0015] The laminated glass 10 is, for example, a windshield for a vehicle, and P-polarized visible light is incident from the interior of the vehicle. The laminated glass 10 is provided with an optical reflective layer 14 in an area where the P-polarized visible light reflected by the concave mirror 90 is incident. The optical reflective layer 14 needs to be formed in at least an area where the P-polarized light from the light source 50 is irradiated, and may be formed on the entire surface of the laminated glass 10.

[0016] The light source 50 is a light source that emits P-polarized visible light, such as a light-emitting diode or a laser. The light source 50 may include optical components such as a polarizing plate that converts S-polarized light to P-polarized light and a lens. The light source 50 is configured with three light sources, for example, a red light source, a green light source, and a blue light source.

[0017] The first optical system 60 is composed of, for example, a prism or lens that combines light emitted from multiple light sources. The image display element 70 is an element that generates an intermediate image, such as a liquid crystal display element or an organic light-emitting element. The second optical system 80 is composed of, for example, a lens or a reflecting mirror. The concave mirror 90 is an optical component that reflects the intermediate image with a reflective surface having a predetermined curvature, and is located closest to the laminated glass 10 among the optical components located on the optical path between the light source 50 and the laminated glass 10.

[0018] In the HUD system 1, light emitted from the light source 50 passes through a first optical system 60 and reaches an image display element 70, where an intermediate image is formed. The intermediate image formed by the image display element 70 is magnified by passing through a second optical system 80 and a concave mirror 90, and is then irradiated onto the optical reflection layer 14 of the laminated glass 10. The intermediate image irradiated onto the optical reflection layer 14 is mainly reflected by the optical reflection layer 14 and guided to a viewpoint I of the occupant, who then recognizes the intermediate image as a virtual image V (HUD image) in front of the laminated glass 10. The occupant may be, for example, the driver of the vehicle.

[0019] 1, θ is the angle of incidence when P-polarized visible light emitted from the light source 50 is incident on the optical reflection layer 14 via a predetermined optical system. The angle of incidence θ may be 57° (Brewster's angle), or may be greater than 57°, or may be less than 57°.

[0020] The HUD system 1 may have any configuration as long as it includes at least the laminated glass 10 and the light source 50. The HUD system 1 may be, for example, a laser scanning system in which a laser beam is scanned by an optical scanning unit formed of a microelectromechanical system (MEMS) or the like.

[0021] While the above describes an example of an HUD system having a light source that emits P-polarized visible light, the laminated glass of the present invention can also be used in an HUD system having a light source that emits S-polarized visible light. In this case, a layer with a relatively high reflectance for the S-polarized component is used as the optical reflective layer 14. Alternatively, the laminated glass of the present invention may be used in an HUD system having a light source that emits both P-polarized and S-polarized light.

[0022] [Laminated Glass] Figures 2A and 2B are diagrams illustrating laminated glass according to the first embodiment. Figure 2A is a schematic diagram showing the laminated glass as viewed from inside the vehicle to outside the vehicle, and Figure 2B is a partial cross-sectional view taken along line IIB-IIB in Figure 2A.

[0023] 2B , the laminated glass 10 is a laminated glass for a vehicle that includes a first glass plate 11, a second glass plate 12, an interlayer film 13, an optically reflective layer 14, a heating function layer 15, and a first concealing layer 16. The laminated glass 10 can be used, for example, in a vehicle windshield.

[0024] The first glass sheet 11 and the second glass sheet 12 are bonded together via an interlayer film 13. The first glass sheet 11 is disposed on a first side that is located on the interior side of the vehicle when the laminated glass 10 is installed in the vehicle, and the second glass sheet 12 is disposed on a second side that is located on the exterior side of the vehicle when the laminated glass 10 is installed in the vehicle.

[0025] The laminated glass 10 may have, for example, a complex curved shape that is curved in both the vertical and horizontal directions when installed in a vehicle. However, the complex curved shape is not limited to a shape that is curved in both the vertical and horizontal directions when installed in a vehicle, but includes a shape that is curved in any two or more different directions. Alternatively, the laminated glass 10 may have a single curved shape that is curved only in the vertical or horizontal direction when installed in a vehicle. However, the single curved shape is not limited to a shape that is curved only in the vertical or horizontal direction when installed in a vehicle, but includes a shape that is curved in any one direction only.

[0026] The laminated glass 10 is preferably curved so as to be convex toward the exterior of the vehicle. That is, the second glass sheet 12 is preferably curved so as to be convex toward the side opposite the interlayer film 13, and the first glass sheet 11 is preferably curved so as to be convex toward the interlayer film 13.

[0027] The first glass sheet 11 is an interior glass sheet that faces the interior side (first side) of the vehicle when the laminated glass 10 is installed in the vehicle. The first glass sheet 11 may be curved. The first glass sheet 11 has a fourth surface 11 located on the opposite side from the interlayer film 13. ４ , and a third surface 11 positioned to face the intermediate film 13. ３ The first glass plate 11 has an upper side, a lower side, and two side sides connecting the upper side and the lower side.

[0028] The second glass sheet 12 is an exterior glass sheet that faces the exterior side (second side) of the vehicle when the laminated glass 10 is installed in the vehicle. The second glass sheet 12 may be curved. The second glass sheet 12 has a second surface 12 that faces the interlayer film 13. ２ , and a first surface 12 located on the opposite side to the intermediate film 13 １ Similar to the first glass plate 11, the second glass plate 12 has, in plan view, an upper side, a lower side, and two side sides connecting the upper side and the lower side.

[0029] When the laminated glass 10 has a curved shape, the minimum value of the radius of curvature is preferably 500 mm or more and 100,000 mm or less. The radii of curvature of the first glass sheet 11 and the second glass sheet 12 may be the same or different. When the radii of curvature of the first glass sheet 11 and the second glass sheet 12 are different, it is preferable that the radius of curvature of the first glass sheet 11 is smaller than the radius of curvature of the second glass sheet 12.

[0030] The first glass plate 11 and the second glass plate 12 are a pair of glass plates facing each other, and the interlayer film 13 is located between the pair of glass plates. The first glass plate 11 and the second glass plate 12 are fixed together with the interlayer film 13 sandwiched therebetween. The interlayer film 13 is a film that bonds the first glass plate 11 and the second glass plate 12 together.

[0031] The outer peripheral side surface of the interlayer film 13 is preferably edge-treated. That is, the outer peripheral side surface of the interlayer film 13 is preferably treated so as not to protrude significantly from the outer peripheral side surfaces of the first glass plate 11 and the second glass plate 12. If the outer peripheral side surface of the interlayer film 13 protrudes from the outer peripheral side surfaces of the first glass plate 11 and the second glass plate 12 by an amount of 150 μm or less, this is preferable in terms of not impairing the appearance. Details of the first glass plate 11, the second glass plate 12, and the interlayer film 13 will be described later.

[0032] The optical reflection layer 14 is a layer that reflects light incident on the first glass plate 11. The optical reflection layer 14 is transparent to visible light. In the example of FIG. 2B , the optical reflection layer 14 is formed on the fourth surface 11 of the first glass plate 11. ４ are located at.

[0033] In the case of a HUD system using P-polarized light, the optical reflective layer 14 is a P-polarized reflective layer. When P-polarized visible light is incident on the P-polarized reflective layer at an incident angle of 55 degrees or more and 75 degrees or less, the visible light reflectance is preferably 10% or more and 30% or less. A visible light reflectance of 10% or more can improve the visibility of the HUD image. A visible light reflectance of 30% or less can reduce the reflection of surrounding objects. Furthermore, to realize a suitable HUD system while reducing the reflection of surrounding objects, the visible light reflectance of the optical reflective layer 14 at an incident angle of 55 degrees or more and 75 degrees or less is preferably 12% or more and 28% or less, more preferably 15% or more and 26% or less.

[0034] The visible light reflectance of the P-polarized reflective layer was measured by measuring the spectral reflectance as specified in ISO 9050:2003 using P-polarized light in the visible wavelength range as incident light at an incident angle θ of 55 degrees or more and 75 degrees or less, and then calculating the visible light reflectance based on this measurement in accordance with the calculation method for visible light reflectance as specified in ISO 9050:2003.

[0035] Examples of the P-polarized reflective layer that can be used include a birefringence interference polarizer made of a polymer multilayer film containing two or more types of polymers with different refractive indices, a polarizer having a fine uneven structure known as a wire grid polarizer, and a film containing a polarizer made of a cholesteric liquid crystal layer. When a P-polarized reflective film is used as the P-polarized reflective layer, the thickness of the P-polarized reflective film is preferably 25 μm or more and 200 μm or less. The thickness of the P-polarized reflective film is more preferably 150 μm or less, and even more preferably 100 μm or less.

[0036] The use of a P-polarized reflective coating as the P-polarized reflective layer is preferable compared to the use of a P-polarized reflective film, because it provides superior visibility at low brightness, such as at night, and at a wider viewing angle. The use of a P-polarized reflective coating is also preferable because it is easy to control the film thickness and the reflective surface tends to be smooth, making the HUD image less likely to be distorted.

[0037] When a P-polarized reflective coating is used as the P-polarized reflective layer, the thickness of the P-polarized reflective coating is, for example, 50 nm to 500 nm. The P-polarized reflective coating can be formed on the surface of the glass plate by, for example, sputtering or CVD.

[0038] Examples of P-polarized light reflective coatings include a film having a laminated structure of a high refractive index film / a low refractive index film, an infrared reflective film having a laminated structure of a metal film such as silver and a dielectric film, and a low-e film made of a transparent conductive film such as ITO. Among these, a film having a laminated structure of a high refractive index film / a low refractive index film is preferred in that it can maintain a high P-polarized light reflectance. When the high refractive index film / a low refractive index film has a two-layer structure, for example, ４ When the high refractive index film / low refractive index film has a three-layer structure or more, the fourth surface 11 of the first glass plate 11 is laminated with the high refractive index film and the low refractive index film in this order. ４ High refractive index films and low refractive index films are alternately laminated in any order on the substrate.

[0039] The refractive index of the high refractive index film is 1.8 or more, or 1.9 or more, or 2.0 or more, or 2.1 or more, and preferably 2.5 or less, at a wavelength of 550 nm. The refractive index of the low refractive index film is typically less than 1.8, or 1.7 or less, or 1.6 or less, and preferably 1.2 or more, at a wavelength of 550 nm.

[0040] Specifically, the high-refractive-index film preferably contains at least one of the following: oxides of Ti, Zr, Nb, and Sn; mixed oxides of Ti, Zr, Nb, Si, Sb, Sn, Zn, and In; nitrides of Si and Zr; and mixed nitrides of Si and Zr. The low-refractive-index film preferably contains at least one of silicon oxide, silicon oxynitride, silicon oxycarbide, or a mixture thereof. Examples of the mixture include a mixed oxide of silicon and aluminum and a mixed oxide of silicon and zirconium.

[0041] The first layer of the high refractive index film is optionally made up of one or more sublayers. The thickness (geometric film thickness) of the first layer of the high refractive index film is preferably 50 nm or more and 100 nm or less, particularly 60 nm or more and 80 nm or less. The first layer of the low refractive index film is optionally made up of one or more sublayers. The thickness (geometric film thickness) of the first layer of the low refractive index film is preferably 70 nm or more and 160 nm or less, particularly 100 nm or more and 140 nm or less.

[0042] In the case of a HUD system using S-polarized light, the optical reflective layer 14 is an S-polarized reflective layer. The S-polarized reflective layer preferably has a visible light reflectance of 18% or more and 30% or less when S-polarized visible light is incident at an incident angle of 55° or more and 75° or less. A visible light reflectance of 18% or more can improve the visibility of the HUD image. A visible light reflectance of 30% or less can reduce the reflection of peripheral objects. Furthermore, to realize a suitable HUD system while reducing the reflection of peripheral objects, the visible light reflectance of the optical reflective layer 14 at an incident angle of 55° or more and 75° or less is preferably 12% or more and 28% or less, more preferably 15% or more and 26% or less.

[0043] The visible light reflectance of the S-polarized reflective layer was measured by measuring the spectral reflectance as specified in ISO 9050:2003 using S-polarized light in the visible wavelength range as incident light at an incident angle θ of 55 degrees or more and 75 degrees or less, and then calculating the visible light reflectance based on the measured spectral reflectance according to the calculation method for visible light reflectance as specified in ISO 9050:2003. ２ and high refractive index materials such as SiO ２ Examples of the optical interference film include an optical interference film in which low refractive index materials such as the above are alternately stacked. Also, the S-polarized light reflective layer may be a film attached to a glass plate with an adhesive layer.

[0044] The optical reflection layer 14 may be a layer that has a holographic function and is transparent to visible light.

[0045] The heating function layer 15 can be disposed closer to the second glass plate 12 than the optical reflection layer 14 in a cross-sectional view. In the example of FIG. 2, the heating function layer 15 is disposed on the second surface 12 of the second glass plate 12. ２The heating function layer 15 is at least partially overlapped with the optical reflection layer 14 in a plan view. The heating function layer 15 may be entirely overlapped with the optical reflection layer 14 in a plan view.

[0046] The heating function layer 15 is configured to be able to receive current from a power source such as a battery via a bus bar. The heating function layer 15 is an anti-fogging means that generates heat when current is supplied. The heating function layer 15 is disposed so that at least a portion thereof overlaps the optical reflective layer 14 in a plan view. Therefore, the heat generated by the heating function layer 15 warms the vicinity of the area of ​​the laminated glass 10 where the optical reflective layer 14 is disposed, thereby removing freezing and fogging in that area.

[0047] The heating function layer 15 is, for example, a heat generating film. For example, a resin film on which a conductive film is formed can be suitably used as the heat generating film. The heating function layer 15 may be a conductive film itself. Examples of conductive films include films of gold, silver, copper, tin-doped indium oxide, etc. These may be single-layer films or multi-layer films. The conductive film may be an infrared-reflecting multi-layer film containing silver.

[0048] Note that contactless power supply may be used to supply power to the heating function layer 15. Contactless power supply is a method of supplying power wirelessly without physical contact using a connector, wiring, etc. For contactless power supply, for example, an electromagnetic induction method may be used in which power is supplied by electromagnetic induction when coils provided on a power supply unit and a power receiving unit that are not in contact with each other are placed close to each other.

[0049] The first concealing layer 16 can be disposed between the optical reflection layer 14 and the heating function layer 15 in a cross-sectional view. In the example of FIG. 2, the first concealing layer 16 is disposed between the third surface 11 of the first glass plate 11 and the optical reflection layer 14. ３ The first concealing layer 16 overlaps the heating function layer 15 in a planar view. The first concealing layer 16 is an opaque layer, and preferably has a visible light transmittance of 1% or less. If the visible light transmittance of the first concealing layer 16 is 1% or less, the heating function layer 15 becomes difficult to see through. It is more preferable that the visible light transmittance of the first concealing layer 16 is 0.5% or less.

[0050] For example, the first concealing layer 16 may be provided on part or all of the bottom peripheral edge of the laminated glass 10 in a plan view. The first concealing layer 16 may be provided on the side peripheral edge and the top peripheral edge of the laminated glass 10 in addition to the bottom peripheral edge of the laminated glass 10 in a plan view. In the example of Fig. 2A, the first concealing layer 16 is provided in a strip shape on the bottom peripheral edge, the side peripheral edge, and the top peripheral edge of the laminated glass 10 in a plan view.

[0051] The width of the first concealing layer 16 in a planar view may be set as appropriate. The width of the first concealing layer 16 in a planar view, other than the information transmission / reception area 19 described below, is, for example, about 10 mm to 350 mm, preferably 20 mm to 300 mm, and more preferably 30 mm to 280 mm. When the first concealing layer 16 is provided on the side and top peripheral edges in addition to the bottom peripheral edge, the width of the bottom peripheral edge may be wider than the widths of the side and top peripheral edges.

[0052] The first concealing layer 16 is, for example, an opaque colored ceramic layer. The color may be any, but dark colors such as black, brown, gray, and dark blue are preferred, with black being more preferred. The first concealing layer 16 can be formed, for example, by applying a ceramic color paste containing a fusible glass frit containing a black pigment onto a glass plate by screen printing or the like and firing the paste, but is not limited to this. The first concealing layer 16 may also be formed, for example, by applying an organic ink containing a black or dark color pigment onto a glass plate by screen printing or the like and drying the ink.

[0053] The presence of the opaque first concealing layer 16 in the laminated glass 10 can suppress ultraviolet degradation of the adhesive that holds the bracket for fixing the information transmitting / receiving device to the laminated glass 10 and the adhesive made of a resin such as urethane that holds the peripheral edge of the laminated glass 10 to the vehicle body. In addition, the adhesive joints are not visible from inside or outside the vehicle, improving the appearance.

[0054] The laminated glass 10 may have an information transmission / reception area 19. The information transmission / reception area 19 is provided within an opening in the first concealing layer 16 of the laminated glass 10. The information transmission / reception area 19 is provided, for example, in the upper peripheral edge portion of the laminated glass 10. The information transmission / reception area 19 is an area where, for example, an information device that uses visible light, such as a visible light camera or an illuminance sensor, or an information device that uses infrared light, such as a LiDAR (Light Detection and Ranging) sensor, transmits and / or receives information. In other words, when the laminated glass 10 is installed in a vehicle, the information device can be placed on the interior side of the information transmission / reception area 19. To achieve high optical quality and enable good transmission and reception of information, the optical reflective layer 14 is not provided within the information transmission / reception area 19.

[0055] A HUD display area R used for a head-up display is defined in a portion of the laminated glass 10. The HUD display area R is an area that can receive light from a light source of the HUD system and displays information by reflecting a projected image from inside the vehicle. The HUD display area R is the range in the eye box based on SAE J1757-2 (2018) where light from a light source 50 is irradiated onto the laminated glass 10 when the HUD display position is moved.

[0056] The HUD display region R can be arranged in a region where the optical reflection layer 14, the heating function layer 15, and the first concealing layer 16 overlap in a planar view. The HUD display region R may be divided into a plurality of locations and arranged in the region where the optical reflection layer 14, the heating function layer 15, and the first concealing layer 16 overlap in a planar view. Note that, apart from the HUD display region R, another HUD display region may be arranged in a position that does not overlap with the first concealing layer 16 in a planar view.

[0057] In this way, in the laminated glass 10, the HUD display region R is defined in the region where the optical reflective layer 14, the heating function layer 15, and the first concealing layer 16 overlap in a plan view. By arranging the opaque first concealing layer 16 in a position that forms the background of the HUD display region R, good contrast is obtained and the visibility of the HUD image is improved. In terms of visibility of the HUD image, it is preferable that the first concealing layer 16 be black.

[0058] Furthermore, the heating function layer 15 is disposed closer to the second glass plate 12 than the optical reflection layer 14 in a cross-sectional view, and at least a portion of the heating function layer 15 overlaps with the optical reflection layer 14 in a plan view, thereby providing an anti-fogging effect. That is, the heat generated by the heating function layer 15 can suppress freezing of moisture adhering to the laminated glass 10 and fogging of the laminated glass 10 due to the temperature difference between the inside and outside of the vehicle, thereby improving the visibility of the HUD image. This contributes to improved safety, particularly when information such as vehicle speed is displayed as the HUD image.

[0059] Furthermore, since the first concealing layer 16 is disposed between the optical reflection layer 14 and the heating function layer 15 in a cross-sectional view and overlaps with the heating function layer 15 in a plan view, the heating function layer 15 becomes less visible from inside the vehicle, improving the visibility of the HUD image. This contributes to improved safety, particularly when information such as the vehicle speed is displayed as the HUD image.

[0060] Here, the first glass plate 11, the second glass plate 12, and the interlayer film 13 will be described in detail.

[0061] [Glass Plates] The first glass plate 11 and the second glass plate 12 may be inorganic glass or organic glass. Examples of inorganic glass include soda-lime glass, aluminosilicate glass, borosilicate glass, alkali-free glass, and quartz glass, without any particular limitations. The second glass plate 12 located on the outer side of the laminated glass 10 is preferably inorganic glass from the viewpoint of scratch resistance, and soda-lime glass from the viewpoint of formability. When the first glass plate 11 and the second glass plate 12 are soda-lime glass, clear glass, green glass containing a predetermined amount or more of iron, and dark green glass are preferably used. Glass that absorbs ultraviolet or infrared light may also be used. Transparent glass is preferred, but colored glass may also be used to the extent that transparency is not impaired. Furthermore, using borosilicate glass for the second glass plate 12 can improve the strength of the laminated glass 10 against flying stones.

[0062] The inorganic glass may be either untempered glass or tempered glass. Untempered glass is produced by forming molten glass into a flat plate and slowly cooling it. Tempered glass is produced by forming a compressive stress layer on the surface of untempered glass. In the case of tempered glass, residual stress can be reduced by distributing stress isotropically.

[0063] The tempered glass may be either physically tempered glass such as air-cooled tempered glass or chemically tempered glass. In the case of physically tempered glass, the glass surface can be tempered by generating a compressive stress layer on the glass surface due to the temperature difference between the glass surface and the interior of the glass by an operation other than gradual cooling, such as rapidly cooling a glass sheet uniformly heated during bending from a temperature near its softening point.

[0064] In the case of chemically strengthened glass, for example, after bending, the glass surface can be strengthened by generating compressive stress on the glass surface by an ion exchange method or the like.

[0065] On the other hand, examples of materials for organic glass include transparent resins such as polycarbonate, acrylic resins such as polymethyl methacrylate, polyvinyl chloride, and polystyrene.

[0066] The first glass sheet 11 and the second glass sheet 12 are not limited to a trapezoidal or rectangular shape, and may be processed into various shapes and curvatures. The first glass sheet 11 and the second glass sheet 12 may be bent using a gravity forming method, a press forming method, a roller forming method, or the like. The forming method for the first glass sheet 11 and the second glass sheet 12 is also not particularly limited. For example, in the case of inorganic glass, glass sheets formed by a float method or the like are preferred.

[0067] The thickness of the second glass sheet 12 is preferably 1.1 mm or more and 3 mm or less at its thinnest portion. When the thickness of the second glass sheet 12 is 1.1 mm or more, the strength, such as resistance to flying stones, is sufficient. On the other hand, when the thickness of the second glass sheet 12 is 3 mm or less, the mass of the laminated glass 10 does not become too large, which is preferable in terms of vehicle fuel efficiency. The thickness of the second glass sheet 12 is more preferably 1.8 mm or more and 2.8 mm or less at its thinnest portion, even more preferably 1.8 mm or more and 2.6 mm or less, even more preferably 1.8 mm or more and 2.2 mm or less, and even more preferably 1.8 mm or more and 2.1 mm or less.

[0068] The thickness of the first glass plate 11 is preferably 0.3 mm or more and 2.3 mm or less. When the thickness of the first glass plate 11 is 0.3 mm or more, the handling property is good. On the other hand, when the thickness of the first glass plate 11 is 2.3 mm or less, the mass does not become too large.

[0069] Furthermore, if the thickness of the first glass plate 11 is not appropriate, when two sheets of glass with particularly deep curves are formed as the first glass plate 11 and the second glass plate 12, a mismatch will occur in the shapes of the two sheets, which will have a significant impact on the glass quality, such as residual stress after crimping.

[0070] However, by setting the thickness of the first glass sheet 11 to 0.3 mm or more and 2.3 mm or less, glass quality such as residual stress can be maintained. Setting the thickness of the first glass sheet 11 to 0.3 mm or more and 2.3 mm or less is particularly effective in maintaining glass quality in glass with a deep curvature. The thickness of the first glass sheet 11 is more preferably 0.5 mm or more and 2.2 mm or less, and even more preferably 0.7 mm or more and 2.1 mm or less. Within this range, the above-mentioned effects become more pronounced. The thickness of the first glass sheet 11 is more preferably 1.0 mm or more, even more preferably 1.3 mm or more, and even more preferably 1.5 mm or more. Furthermore, the thickness of the first glass sheet 11 is more preferably 2.0 mm or less, and even more preferably 1.9 mm or less.

[0071] The first glass sheet 11 and / or the second glass sheet 12 may not have a constant thickness, but may have a thickness that varies from location to location as necessary. For example, if the laminated glass 10 is a windshield, one or both of the first glass sheet 11 and the second glass sheet 12 may have a wedge-shaped cross section whose thickness increases from the bottom edge to the top edge of the windshield when the windshield is installed in a vehicle. In this case, if the thickness of the interlayer film 13 is constant, the total wedge angle of the first glass sheet 11 and the second glass sheet 12 varies, for example, within a range of more than 0 mrad to 1.0 mrad.

[0072] A coating having water-repellent properties and ultraviolet and infrared blocking properties, or a coating having low reflectivity and low radiation properties may be provided on the outer surface of the first glass plate 11 and / or the second glass plate 12. Furthermore, a coating having ultraviolet and infrared blocking properties, low radiation properties, visible light absorption properties, coloring, etc. may be provided on the surface of the first glass plate 11 and / or the second glass plate 12 that contacts the interlayer film 13.

[0073] When the first glass sheet 11 and the second glass sheet 12 are curved inorganic glass sheets, the first glass sheet 11 and the second glass sheet 12 are bent after being formed by a float method or the like and before being bonded with the interlayer film 13. The bending is performed by heating the glass to soften it. The heating temperature of the glass during bending is preferably controlled within a range of approximately 550°C to 700°C.

[0074] [Interlayer Film] Thermoplastic resins are often used for the interlayer film 13, and examples thereof include thermoplastic resins that have conventionally been used for this type of application, such as 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. In addition, resin compositions containing modified hydrogenated block copolymers, as described in Japanese Patent No. 6,065,221, can also be suitably used.

[0075] Among these, plasticized polyvinyl acetal resins are preferably used because they have an excellent balance of properties such as transparency, weather resistance, strength, adhesive strength, penetration resistance, impact energy absorption, moisture resistance, heat insulation, and sound insulation. These thermoplastic resins may be used alone or in combination of two or more. The term "plasticized" in the plasticized polyvinyl acetal resin means that the resin has been plasticized by adding a plasticizer. The same applies to other plasticized resins.

[0076] However, when a specific substance is encapsulated in the interlayer film 13, depending on the type of substance, the substance may be deteriorated by a specific plasticizer, and in such a case, it is preferable to use a resin that does not substantially contain that plasticizer. Examples of resins that do not contain plasticizers include ethylene-vinyl acetate copolymer (EVA) resins.

[0077] Examples of the polyvinyl acetal resin include polyvinyl formal resin obtained by reacting polyvinyl alcohol (PVA) with formaldehyde, polyvinyl acetal resin in the narrow sense obtained by reacting PVA with acetaldehyde, and polyvinyl butyral (PVB) resin obtained by reacting PVA with n-butylaldehyde. PVB is particularly preferred because it has an excellent balance of properties such as transparency, weather resistance, strength, adhesive strength, penetration resistance, impact energy absorbency, moisture resistance, heat insulation, and sound insulation. These polyvinyl acetal resins may be used alone or in combination of two or more.

[0078] However, the material forming the interlayer 13 is not limited to a thermoplastic resin. The interlayer 13 may also contain functional particles such as an infrared absorber, an ultraviolet absorber, or a light-emitting agent. The interlayer 13 may also have a colored portion called a shade band. The color pigment used to form the colored portion is one that can be used for plastics, and the amount added may be adjusted so that the colored portion has a visible light transmittance of 40% or less. Examples of the color pigment include organic color pigments such as azo-based, phthalocyanine-based, quinacridone-based, perylene-based, perinone-based, dioxazine-based, anthraquinone-based, and isoindolino-based pigments, and inorganic color pigments such as oxides, hydroxides, sulfides, chromates, sulfates, carbonates, silicates, phosphates, arsenates, ferrocyanides, carbon, and metal powders. These color pigments may be used alone or in combination of two or more.

[0079] The interlayer film 13 may have multiple layers. For example, the interlayer film 13 may include three or more layers. For example, if the interlayer film is formed of three or more layers and the shear modulus of any layer other than the two outermost layers is set to be smaller than the shear modulus of the two outermost layers by adjusting the plasticizer or the like, the sound insulation of the laminated glass 10 can be improved. In this case, the shear modulus of the two outermost layers may be the same or different.

[0080] The thickness of the interlayer film 13 is preferably 0.5 mm or more at its thinnest part. When the interlayer film 13 has multiple layers, the thickness of the interlayer film 13 is the sum of the thicknesses of the individual layers. When the thickness of the interlayer film 13 at its thinnest part is 0.5 mm or more, the impact resistance required for laminated glass is sufficient. Furthermore, the thickness of the interlayer film 13 is preferably 2 mm or less at its thickest part. When the maximum thickness of the interlayer film 13 is 2 mm or less, the mass of the laminated glass does not become too large. The maximum thickness of the interlayer film 13 is more preferably 1.5 mm or less, and even more preferably 1.2 mm or less.

[0081] Furthermore, when the interlayer film 13 has multiple layers, it is desirable that each layer included in the interlayer film 13 be formed of the same material, but they may also be formed of different materials. However, from the viewpoint of adhesion to the first glass sheet 11 and the second glass sheet 12, or functional materials to be incorporated into the laminated glass 10, it is desirable that 50% or more of the thickness of the interlayer film 13 be made of the above-mentioned materials.

[0082] The interlayer film 13 does not have to have a constant thickness, and the thickness may vary from location to location as necessary. For example, if the laminated glass 10 is a windshield, the interlayer film 13 may have a wedge-shaped cross section whose thickness increases from the bottom edge to the top edge of the windshield when the windshield is installed in a vehicle. In this case, if the thicknesses of the first glass sheet 11 and the second glass sheet 12 are constant, the wedge angle of the interlayer film 13 varies, for example, within a range of more than 0 mrad to 1.0 mrad.

[0083] To produce the interlayer film 13, for example, an appropriate resin material for the interlayer film is selected from the above-mentioned materials and extruded in a heated, molten state using an extruder. The extrusion conditions, such as the extrusion speed, of the extruder are set to ensure uniformity. The extruded resin film is then stretched in any direction as necessary to impart curvature to the upper and lower edges in accordance with the design of the laminated glass, thereby completing the interlayer film 13.

[0084] [Laminated Glass] The total thickness of the laminated glass 10 is preferably 2.8 mm or more and 10 mm or less. If the total thickness of the laminated glass 10 is 2.8 mm or more, sufficient rigidity can be ensured. Furthermore, if the total thickness of the laminated glass 10 is 10 mm or less, sufficient transmittance can be obtained and haze can be reduced. The total thickness of the laminated glass 10 is preferably 7 mm or less, more preferably 6 mm or less, and even more preferably 5 mm or less.

[0085] The misalignment between the first glass sheet 11 and the second glass sheet 12 is preferably 1.5 mm or less, and more preferably 1 mm or less, along at least one side of the laminated glass 10. Here, the misalignment between the first glass sheet 11 and the second glass sheet 12 refers to the amount of misalignment between the outer peripheral side surface of the first glass sheet 11 and the outer peripheral side surface of the second glass sheet 12 in a plan view.

[0086] It is preferable that the misalignment between the first glass sheet 11 and the second glass sheet 12 be 1.5 mm or less along at least one side of the laminated glass 10, since it does not impair the appearance. It is even more preferable that the misalignment between the first glass sheet 11 and the second glass sheet 12 be 1.0 mm or less along at least one side of the laminated glass 10, since it does not impair the appearance.

[0087] [Method for Manufacturing Laminated Glass] To manufacture the laminated glass 10, first, the third surface 11 ３ and fourth surface 11 ４ a first glass plate 11 having an intermediate film 13 and a first surface 12 １ and the second surface 12 ２ and a second glass plate 12 having the above-mentioned structure. The thicknesses of the first glass plate 11 and the second glass plate 12 are constant. The film thickness of the interlayer film 13 is constant. Note that the first glass plate 11 or the second glass plate 12, or the interlayer film 13, may have a wedge-shaped cross section.

[0088] Next, the fourth surface 11 of the first glass plate 11 ４ For example, the optical reflection layer 14 is formed on the fourth surface 11 of the first glass plate 11 by sputtering, CVD, or the like. ４ Alternatively, the optical reflection layer 14 may be formed on a large piece of glass, and then the glass may be cut to prepare the first glass plate 11 on which the optical reflection layer 14 is formed.

[0089] Next, the third surface 11 of the first glass plate 11 ３ When the first concealing layer 16 is a colored ceramic layer, for example, a ceramic color paste is applied to the third surface 11 of the first glass plate 11. ３ The coating can be formed by applying the coating by screen printing or the like to the substrate and then firing the coating.

[0090] Next, the second surface 12 of the second glass plate 12 ２ For example, when the heating function layer 15 is a conductive film, the heating function layer 15 is formed on the second surface 12 of the second glass plate 12 by using a physical vapor deposition (PVD) method such as a sputtering method, a vacuum deposition method, or an ion plating method. ２ The conductive film may be formed by chemical vapor deposition (CVD) or wet coating.

[0091] Next, after the step of forming the optical reflective layer 14 and the first concealing layer 16 and the step of forming the heating function layer 15, the first glass plate 11 and the second glass plate 12 are bent. For example, a press molding method can be used to bend the first glass plate 11 and the second glass plate 12. Specifically, a forming mold with concaves and convexes corresponding to the final shape of the laminated glass 10 is prepared, and the first glass plate 11 and the second glass plate 12 are heated to a predetermined temperature to soften them, and then pressed using this forming mold to bend the first glass plate 11 and the second glass plate 12. The first glass plate 11 and the second glass plate 12 may be bent using a gravity forming method, a roller forming method, or the like. When the optical reflective layer 14 is a film, the film may be laminated simultaneously with the first glass plate 11 and the second glass plate 12 in a step of sandwiching the interlayer 13 to form a laminate after bending the first glass plate 11 and the second glass plate 12, or may be attached to the glass surface after the laminated glass 10 is produced.

[0092] In the laminated glass 10, the difference in thickness between the first glass sheet 11 and the second glass sheet 12 is preferably 0.3 mm or less, and more preferably 0.2 mm or less. It is particularly preferable that the thicknesses of the first glass sheet 11 and the second glass sheet 12 are the same. The smaller the difference in thickness between the first glass sheet 11 and the second glass sheet 12, the more similar their behaviors during bending become, thereby reducing perspective distortion.

[0093] Next, the interlayer film 13 is stretched as necessary. Then, the third surface 11 of the first glass plate 11 is ３ and the second surface 12 of the second glass plate 12２ The intermediate film 13 is placed between the first glass plate 11 and the second glass plate 12 and pressure-bonded. For example, a laminate is formed by sandwiching the intermediate film 13 between the first glass plate 11 and the second glass plate 12 with the optical reflective layer 14 facing outward. Then, for example, this laminate is placed in a rubber bag, a rubber chamber, a resin bag, or the like, and bonded at a temperature controlled in the range of approximately 70°C to 110°C in a vacuum controlled at a gauge pressure in the range of -100 kPa to -65 kPa. The heating conditions, temperature conditions, and lamination method are selected as appropriate.

[0094] Furthermore, for example, by performing a heating and pressing process under controlled conditions of a temperature in the range of 100°C to 150°C and an absolute pressure in the range of 0.6 MPa to 1.5 MPa, a laminated glass 10 with even greater durability can be obtained. However, in some cases, this heating and pressing process may not be used in consideration of simplification of the process and the properties of the material to be sealed in the laminated glass 10. The laminated glass 10 is completed through the above processes.

[0095] Alternatively, a so-called cold bending method may be used in which the second glass sheet 12 is bent in advance, and the first glass sheet 11, which is in a flat state sandwiched between the interlayer film 13, is curved to match the shape of the second glass sheet 12 and bonded to produce the laminated glass 10.

[0096] In addition to the interlayer 13, films or devices having functions such as heating, infrared reflection, light emission, power generation, light control, touch panel, visible light reflection, scattering, decoration, and absorption may be provided between the first glass sheet 11 and the second glass sheet 12, as long as the effects of the present invention are not impaired. Furthermore, the surface of the laminated glass 10 may have a film having functions such as anti-fogging, water repellency, heat insulation, and low reflection. ３ and the second surface 11 of the second glass plate 12 ２ The insulating layer may have a film having a function of heat insulation, heat generation, etc.

[0097] <Modification> Fig. 3 is a cross-sectional view illustrating a laminated glass according to Modification 1 of the first embodiment. The laminated glass 10A shown in Fig. 3 differs from the laminated glass 10 in that the first concealing layer 16 is replaced with a first concealing layer 26.

[0098] In the laminated glass 10A shown in FIG. 3 , the first concealing layer 26 is a colored interlayer film with light-blocking properties. The colored interlayer film can be produced by coloring the materials exemplified in the description of the interlayer film in the first embodiment. Specifically, the colored interlayer film can be obtained by adding a colorant to a composition containing mainly a thermoplastic resin. The colored interlayer film may contain a plasticizer to adjust the glass transition point. The colored interlayer film may be laminated on the interlayer film 13 as a thin film having a thickness of 20 μm to 70 μm.

[0099] The colorant is not particularly limited as long as it reduces the visible light transmittance, and examples thereof include dyes, inorganic pigments, organic pigments, etc. Among these, inorganic pigments or organic pigments are preferred because they are less likely to fade over long-term use, and inorganic pigments are preferred because they have excellent light resistance.

[0100] Examples of organic pigments include black pigments such as aniline black and red pigments such as alizarin lake. Examples of inorganic pigments include carbon-based pigments and metal oxide-based pigments. Examples include black pigments such as carbon black, ivory black, mars black, peach black, lamp black, and magnetite triiron tetroxide; brown pigments such as umber, Burton umber, Yellow Walker, Van Dyke Brown, sienna, and Burton sienna; red pigments such as red iron oxide, molybdenum red, and cadmium red; orange pigments such as red chrome yellow and chrome vermilion; blue pigments such as ultramarine, Prussian blue, cobalt blue, and cerulean blue; green pigments such as chromium oxide, pyridian, emerald green, and cobalt green; yellow pigments such as chrome yellow, cadmium yellow, yellow iron oxide, and titanium yellow; and purple pigments such as manganese violet and mineral violet. These colorants may be used alone or in combination.

[0101] The colored interlayer film may further contain one or more of various additives, such as an infrared absorber, an ultraviolet absorber, a fluorescent agent, an adhesion modifier, a coupling agent, a surfactant, an antioxidant, a heat stabilizer, a light stabilizer, a dehydrating agent, an antifoaming agent, an antistatic agent, and a flame retardant.

[0102] The method for forming the colored interlayer film is not particularly limited, but for example, an uncolored thermoplastic resin composition that will become the interlayer film 13 and a colored thermoplastic resin composition that will become the first concealing layer 26 are each prepared in advance. Then, the uncolored thermoplastic resin composition and the colored thermoplastic resin composition are joined together, for example, in a sheet molding die, and the two resin compositions are molded into a sheet while being bonded together. This results in the interlayer film 13 and the first concealing layer 26.

[0103] Alternatively, an incision may be made in a portion of the interlayer film 13 formed from the uncolored thermoplastic resin composition, and a colored thermoplastic resin composition may be co-extruded into the incision to form the first concealing layer 26. Furthermore, the interlayer film 13 and the first concealing layer 26 can also be obtained by molding each of the uncolored thermoplastic resin composition and the colored thermoplastic resin composition into sheets of a predetermined size and shape and laminating them together in the plane direction.

[0104] The colored interlayer film may be prepared by forming a dark-colored printed layer on the surface of an uncolored thermoplastic resin composition. A typical printing method using a colored material on a resin substrate can be used to form the dark-colored printed layer. Examples of the colored material include organic pigments and inorganic pigments similar to the colorants described above. In this case, the printed layer does not require durability at temperatures near the softening point of glass, as is the case with a ceramic concealing layer, and therefore, for example, organic pigments containing carbon black can be used.

[0105] As described above, the first concealing layer is not limited to the colored ceramic layer exemplified in the first embodiment, and may be a colored interlayer. Furthermore, the first concealing layer may be a colored film with light-blocking properties, a combination of two or more types of materials, such as a colored film, a colored interlayer, and a colored ceramic layer, or a layer with a dimming function. Examples of substrates for the colored film include polyethylene terephthalate, polycarbonate, and acrylic. Furthermore, the colored film may be integrated with an infrared reflective film or the like. Even when a colored interlayer or the like is used as the first concealing layer, the visibility of the HUD image can be improved, as in the first embodiment.

[0106] Fig. 4 is a cross-sectional view illustrating a laminated glass according to Modification 2 of the first embodiment. The laminated glass 10B shown in Fig. 4 differs from the laminated glass 10 in that a second concealing layer 17 is added.

[0107] The second concealing layer 17 can be disposed closer to the second glass plate 12 than the heating function layer 15 in a cross-sectional view. In the example of FIG. 4 , the second concealing layer 17 is disposed on the second surface 12 of the second glass plate 12. ２ The second concealing layer 17 overlaps the heating function layer 15 in a plan view. The second concealing layer 17 is an opaque layer. The second concealing layer 17 may be the same layer as the first concealing layer 16. That is, the second concealing layer 17 is, for example, a colored ceramic layer, a colored interlayer, a colored film, or a combination of two or more of these. The visible light transmittance of the second concealing layer is preferably 1% or less, and more preferably 0.5% or less.

[0108] The laminated glass 10B can improve the visibility of the HUD image, as in the first embodiment. Furthermore, in the laminated glass 10B, the second concealing layer 17 is disposed closer to the second glass plate 12 than the heating function layer 15 in a cross-sectional view, making the heating function layer 15 less visible from outside the vehicle, thereby improving the appearance from outside the vehicle. Furthermore, the heating function layer 15 is less likely to be irradiated with ultraviolet light from outside the vehicle, thereby suppressing deterioration of the heating function layer 15.

[0109] 5A and 5B are diagrams (part 1) illustrating a laminated glass according to Modification 3 of the first embodiment, in which Fig. 5A is a schematic diagram illustrating the laminated glass as viewed from inside the vehicle to outside the vehicle, and Fig. 5B is a partial cross-sectional view taken along line VB-VB in Fig. 5A . However, for convenience, Fig. 5A illustrates only the second glass plate 12, the second concealing layer 17, and the heating function layer 25.

[0110] The laminated glass 10C shown in Figures 5A and 5B differs from the laminated glass 10B in that the heating function layer 15 is replaced with a heating function layer 25. The heating function layer 25 is a conductive wire. Examples of materials for the conductive wire include gold, silver, copper, aluminum, tungsten, platinum, palladium, nickel, cobalt, titanium, iridium, zinc, magnesium, and tin. These metals may be plated, alloyed, or composites with resin. The conductive wire may be formed by an etching method such as photolithography, or by a printing method such as screen printing, inkjet printing, offset printing, flexographic printing, or gravure printing.

[0111] The line width of the conductive wires in the portion overlapping with the optical reflection layer 14 in a planar view is preferably 150 μm or less, and more preferably 120 μm or less. This increases the resistance value of the conductive wires and sufficiently increases the heat generation amount. Furthermore, when the width of the conductive wires is 150 μm or less, the density of the conductive wires can be increased, allowing the object to be heated uniformly. The line widths of the conductive wires may be the same, or at least some of the conductive wires may have different line widths. In the example of Figures 5A and 5B, at least some of the conductive wires constituting the heating function layer 25 have different line widths, with the center being narrower than the outer sides in the direction perpendicular to the direction in which the conductive wires extend.

[0112] The laminated glass 10C can improve the visibility of the HUD image, as in the first embodiment. Furthermore, the laminated glass 10C uses conductive wires as the heating function layer 25, and at least some of the conductive wires constituting the heating function layer 25 have different line widths, with the central line width being narrower than the outer lines in a direction perpendicular to the direction in which the conductive wires extend. This allows the amount of heat generated at the central side to be greater than the outer lines. Therefore, the central side is less likely to fogging, and any fogging at the central side clears quickly, thereby improving the visibility of the HUD image projected toward the central side of the optical reflection layer 14. Furthermore, since the amount of heat generated can be increased only in the necessary areas, this contributes to energy conservation of the vehicle battery. The position where the line width is narrowed is not limited to the central side, and may be any position where anti-fogging is desired as a priority.

[0113] 6A and 6B are diagrams (part 2) illustrating a laminated glass according to Modification 3 of the first embodiment, and are plan views corresponding to FIG. 5A. In the example of FIG. 6A, at least some of the conductive wires constituting the heating function layer 25 have different spacings. Specifically, the spacing between the conductive wires is narrower at the center than at either side in a direction perpendicular to the direction in which the conductive wires constituting the heating function layer 25 extend.

[0114] This allows the amount of heat generated at the center to be greater than at either outer side. Therefore, as described above, the visibility of the HUD image irradiated at the center of the optical reflective layer 14 can be improved. In addition, since the amount of heat generated can be increased only in the necessary areas, this contributes to energy conservation of the vehicle battery. Note that the position where the gap is narrowed is not limited to the center, and may be any position where anti-fogging is desired as a priority.

[0115] As shown in Figure 6B, at least some of the conductive wires constituting the heating function layer 25 may be arranged with different densities. In the example of Figure 6B, the density of conductive wires is higher on the side in front of the driver's seat when the heating function layer 25 is installed in a vehicle than on the side in front of the passenger seat. This allows the amount of heat generated on the side in front of the driver's seat to be greater than on the side in front of the passenger seat. Therefore, as described above, the visibility of the HUD image irradiated onto the optical reflection layer 14 located in front of the driver's seat can be improved.

[0116] 5A, 6A, and 6B, the patterns formed by the conductive lines are not limited to straight lines, and may be wavy lines (e.g., sine waves, triangular waves, rectangular waves, etc.), or combinations of wavy lines and straight lines. The conductive lines may also intersect with each other. For example, the conductive lines may be in a mesh pattern. The heating function layer 25 may be provided over the entire area between the left and right sides of the laminated glass, or only in necessary areas. In addition, in FIGS. 5A, 6A, and 6B, the second concealing layer 17 is not provided, and the conductive lines are provided on the second surface 12 of the second glass plate 12. ２ It may also be provided directly on

[0117] In this way, by using a conductive wire as the heating function layer, the resistance becomes higher than when the heating function layer is a film, and the amount of heat generated can be increased. Furthermore, when the heating function layer is a conductive wire, the heating function layer is more easily visible from the inside of the vehicle than when the heating function layer is a film, so it is more effective to provide the first concealing layer closer to the inside of the vehicle than the heating function layer. Note that in both the first embodiment and the modified example, a conductive wire, a heat-generating film, or a conductive film can be used as the heating function layer.

[0118] Fig. 7 is a diagram illustrating a laminated glass according to Modification 4 of the first embodiment. The laminated glass 10D shown in Fig. 7 differs from the laminated glass 10C in the position of the first concealing layer 16.

[0119] In the laminated glass 10D, the first concealing layer 16, the heating function layer 25, and the second concealing layer 17 are laminated in contact with each other. ２ The second concealing layer 17 is disposed on the first glass plate 11, the heating function layer 25 is laminated directly on the surface of the second concealing layer 17 facing the first glass plate 11, and the first concealing layer 16 is laminated directly on the surface of the heating function layer 25 facing the first glass plate 11. In this way, the first concealing layer 16 does not need to be in contact with the first glass plate 11.

[0120] The laminated glass 10D can improve the visibility of HUD images, as in the first embodiment. Furthermore, in the laminated glass 10D, the first concealing layer 16, the heating function layer 25, and the second concealing layer 17 are laminated in contact with each other, and the heating function layer 25 is completely covered by the first concealing layer 16 and the second concealing layer 17. This structure prevents ultraviolet light from outside the vehicle from irradiating the heating function layer 25, thereby suppressing deterioration of the heating function layer 25. Furthermore, when the first concealing layer 16 and the second concealing layer 17 are colored ceramic layers, the heating function layer 25 does not come into contact with the plasticizer-containing resin that constitutes the interlayer film 13, and is therefore not affected by the plasticizer.

[0121] 8A and 8B are diagrams illustrating a laminated glass according to Modification 5 of the first embodiment. Fig. 8A is a partial plan view schematically illustrating the laminated glass as viewed from inside the vehicle to outside the vehicle, and Fig. 8B is a partial cross-sectional view taken along line VIIIB-VIIIB in Fig. 8A. The laminated glass 10E shown in Figs. 8A and 8B differs from the laminated glass 10B in that the first concealing layer 16 is replaced with a first concealing layer 36.

[0122] The first concealing layer 36 is, for example, a colored ceramic layer. The first concealing layer 36 has a band-shaped region 361 and a dotted region 362. The band-shaped region 361 is a region in which the concealing layer is continuously formed without gaps. The dotted region 362 is a region in which, in a plan view, a plurality of dots are scattered along the edge of the inner edge of the band-shaped region 361. The inner edge side of the band-shaped region 361 is the side opposite the bottom edge of the laminated glass 10E, i.e., the upper edge direction in the case of a vehicle windshield.

[0123] For example, in a plan view, the band-shaped region 361 is disposed along the peripheral edge of the bottom edge of the laminated glass 10E, and the dotted region 362 is disposed along the entire inner edge of the band-shaped region 361. Alternatively, the dotted region 362 may be disposed along a portion of the inner edge of the band-shaped region 361. In the dotted region 362, the visible light transmittance gradually increases in the direction away from the peripheral edge of the bottom edge of the laminated glass 10E, i.e., in the case of a vehicle windshield, toward the top edge.

[0124] The laminated glass 10E can improve the visibility of the HUD image, as in the first embodiment. Furthermore, in the laminated glass 10E, the dot density in the dot region 362 is adjusted so that it is denser near the band region 361 and becomes sparser as it moves away from the band region 361, forming a gradation pattern. In the example of Figures 8A and 8B, the gradation pattern is formed by making the dots smaller in diameter in the rows farther from the band region 361. This makes it possible to make the inner edge side of the first concealing layer 36 less noticeable.

[0125] Furthermore, even if misalignment occurs at the end of the inner edge of a layer that is located closer to the exterior of the vehicle than the first concealing layer 36, the gradation pattern can conceal it. Furthermore, the difference in heat absorption between the area where the first concealing layer 36 is formed and the area where it is not formed can be made gentler, which is effective in reducing perspective distortion.

[0126] In the laminated glass 10E, the second concealing layer 17 is not provided, and the heating function layer 15 is provided on the second surface 12 of the second glass plate 12. ２ Alternatively, when the laminated glass 10E has the second concealing layer 17, the second concealing layer 17 may have a region in which the visible light transmittance gradually increases on the side opposite the peripheral edge of the bottom edge of the laminated glass 10E, i.e., toward the top edge of the vehicle windshield. Alternatively, the first concealing layer 16 may not have a region in which the visible light transmittance gradually increases, and only the second concealing layer 17 may have a region in which the visible light transmittance gradually increases.

[0127] Fig. 9 is a diagram illustrating a laminated glass according to Modification 6 of the first embodiment. The laminated glass 10F shown in Fig. 9 differs from the laminated glass 10A in that the first concealing layer 26 is replaced with a first concealing layer 46.

[0128] The laminated glass 10F can improve the visibility of HUD images, similar to the first embodiment. Furthermore, in the laminated glass 10F, the first concealing layer 46 is a colored interlayer film, but its tip portion gradually tapers in cross-sectional view. The tip portion of the first concealing layer 46 is located on the opposite side of the bottom edge of the laminated glass 10F, and is a region in which the visible light transmittance gradually increases with increasing distance from the bottom edge of the laminated glass 10F, i.e., toward the top edge of the vehicle windshield. That is, the tip portion of the first concealing layer 46 forms a gradation pattern. This makes the inner edge of the first concealing layer 46 less noticeable. Furthermore, even if misalignment occurs at the inner edge of a layer located closer to the vehicle exterior than the first concealing layer 46, the gradation pattern can conceal it.

[0129] In the laminated glass 10F, the second concealing layer 17 is not provided, and the heating function layer 15 is provided on the second surface 12 of the second glass plate 12. ２Alternatively, when the laminated glass 10F has the second concealing layer 17, the second concealing layer 17 may have a region in which the visible light transmittance gradually increases on the side opposite the peripheral edge of the bottom edge of the laminated glass 10F, i.e., toward the top edge of the vehicle windshield. Alternatively, the first concealing layer 46 may not have a region in which the visible light transmittance gradually increases, and only the second concealing layer 17 may have a region in which the visible light transmittance gradually increases.

[0130] 10 is a diagram illustrating a laminated glass according to Modification 7 of the first embodiment. The laminated glass 10G shown in FIG. 10 differs from the laminated glass 10 in the position of the heating function layer 15.

[0131] In the laminated glass 10G, a heating function layer 15 is laminated on the second glass plate 12 side of the first concealing layer 16. The surface of the heating function layer 15 facing the first glass plate 11 is in contact with the first concealing layer 16, and the surface of the heating function layer 15 facing the second glass plate 12 is in contact with the interlayer 13.

[0132] In this way, the heating function layer 15 may be laminated on the first concealing layer 16. In the laminated glass 10G, the visibility of the HUD image can be improved as in the first embodiment. ３ By being located closer to the fourth surface 11 of the first glass plate 11, ４ This allows heat to be transferred more efficiently.

[0133] In the laminated glass 10G, the second surface 12 ２ Alternatively, a second concealing layer 17 may be provided on the surface of the heating functional layer 15 facing the second glass plate 12 .

[0134] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0135] For example, in the above-described embodiment and modified examples, the optical reflection layer 14 is formed on the fourth surface 11 of the first glass plate 11. ４However, the optical reflective layer 14 may be located at any position where it can reflect light from the light source of the HUD system. For example, the optical reflective layer 14 may be located at the third surface 11 of the first glass plate 11. ３ Alternatively, the optical reflective layer 14 may be provided on the inner surface of the first concealing layer 16 in FIG. 7. ４ This is advantageous in that it can reduce double images.

[0136] In addition to the above embodiments, the following supplementary notes are further disclosed. (Supplementary Note 1) A laminated glass including a first glass plate, a second glass plate, and an interlayer film positioned between the first glass plate and the second glass plate and bonding the first glass plate to the second glass plate, the laminated glass having: an optical reflective layer that reflects light incident from the first glass plate; a heating function layer that is positioned closer to the second glass plate than the optical reflective layer in a cross-sectional view and at least a portion of which overlaps with the optical reflective layer in a planar view; and a first concealing layer that is positioned between the optical reflective layer and the heating function layer in a cross-sectional view and overlaps with the heating function layer in a planar view. (Supplementary Note 2) The laminated glass according to Supplementary Note 1, wherein the first concealing layer is provided on a part or all of a peripheral portion of a lower edge of the laminated glass in a planar view. (Supplementary Note 3) The laminated glass according to Supplementary Note 1 or 2, wherein the heating function layer is a conductive wire, a heat-generating film, or a conductive film. (Appendix 4) The laminated glass according to Appendix 3, wherein the heating function layer is a conductive line, and at least some of the conductive lines have different line widths. (Appendix 5) The laminated glass according to Appendix 3 or 4, wherein the heating function layer is a conductive line, and at least some of the conductive lines have different intervals. (Appendix 6) The laminated glass according to any one of Appendix 3 to 5, wherein the heating function layer is a conductive line, and the line width of a portion that overlaps with the optical reflective layer in a plan view is 150 μm or less. (Appendix 7) The laminated glass according to any one of Appendix 1 to 6, wherein the first concealing layer is a colored ceramic layer. (Appendix 8) The laminated glass according to any one of Appendix 1 to 7, wherein the first concealing layer is a colored interlayer film. (Appendix 9) The laminated glass according to any one of Appendix 1 to 8, wherein the first concealing layer is a colored film. (Appendix 10) The laminated glass according to any one of Appendices 1 to 6, wherein the first concealing layer is a layer having a light control function. (Appendix 11) The laminated glass according to any one of Appendices 1 to 9, wherein the first concealing layer has a region in which the visible light transmittance gradually increases on the side opposite to the peripheral edge of the laminated glass. (Appendix 12) The laminated glass according to any one of Appendices 1 to 10, further comprising a second concealing layer that is arranged closer to the second glass plate than the heating function layer in a cross-sectional view and overlaps with the heating function layer in a plan view.(Appendix 13) The laminated glass according to Appendix 12, wherein the first concealing layer, the heating function layer, and the second concealing layer are laminated in contact with each other. (Appendix 14) The laminated glass according to Appendix 12 or 13, wherein the second concealing layer is a colored ceramic layer, a colored interlayer, or a colored film. (Appendix 15) The laminated glass according to any one of Appendixes 12 to 14, wherein the second concealing layer has a region where the visible light transmittance gradually increases on the side opposite to the peripheral edge of the laminated glass. (Appendix 16) The laminated glass according to any one of Appendixes 1 to 15, wherein the optical reflective layer has a visible light reflectance of 10% or more when P-polarized visible light is incident at an incident angle of 55 degrees or more and 75 degrees or less. (Supplementary Note 17) The laminated glass according to any one of Supplementary Notes 1 to 15, wherein the optical reflective layer has a visible light reflectance of 18% or more when S-polarized visible light is incident at an incident angle of 55 degrees or more and 75 degrees or less. (Supplementary Note 18) The laminated glass according to any one of Supplementary Notes 1 to 17, wherein the optical reflective layer is disposed on the surface of the first glass plate opposite to the interlayer film. The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2023-115748, filed on July 14, 2023, are hereby incorporated by reference as if fully set forth in the specification of the present invention.

[0137] 1 HUD system 10, 10A, 10B, 10C, 10D, 10E, 10F, 10G Laminated glass 11 First glass plate 11 ３ 3rd page 11 ４ Fourth surface 12 Second glass plate 12 １ 1st page 12 ２ Second surface 13 Intermediate film 14 Optical reflection layer 15, 25 Heating function layer 16, 26, 36, 46 First concealing layer 17 Second concealing layer 19 Information transmitting / receiving area 50 Light source 60 First optical system 70 Image display element 80 Second optical system 90 Concave mirror 361 Strip area 362 Dot area

Claims

1. A laminated glass comprising a first glass plate, a second glass plate, and an intermediate film located between the first glass plate and the second glass plate and bonding the first glass plate to the second glass plate, the laminated glass having: an optical reflective layer that reflects light incident from the first glass plate; a heating function layer that is located closer to the second glass plate than the optical reflective layer in a cross-sectional view and at least a portion of which overlaps with the optical reflective layer in a planar view; and a first concealing layer that is located between the optical reflective layer and the heating function layer in a cross-sectional view and overlaps with the heating function layer in a planar view.

2. The laminated glass according to claim 1, wherein the first concealing layer is provided on all or part of the lower peripheral edge of the laminated glass in a plan view.

3. The laminated glass according to claim 1, wherein the heating functional layer is a conductive wire, a heat generating film, or a conductive film.

4. The laminated glass according to claim 3, wherein the heating functional layer is a conductive line, and at least some of the conductive lines have different line widths.

5. The laminated glass according to claim 3, wherein the heating functional layer is a conductive line, and at least some of the conductive lines have different intervals from each other.

6. The laminated glass according to claim 3, wherein the heating functional layer is a conductive line, and the line width of the portion overlapping with the optical reflection layer in a plan view is 150 μm or less.

7. The laminated glass according to any one of claims 1 to 6, wherein the first concealing layer is a colored ceramic layer.

8. The laminated glass according to any one of claims 1 to 6, wherein the first concealing layer is a colored interlayer.

9. The laminated glass according to any one of claims 1 to 6, wherein the first concealing layer is a colored film.

10. The laminated glass according to any one of claims 1 to 6, wherein the first concealing layer is a layer having a light control function.

11. The laminated glass according to any one of claims 1 to 6, wherein the first concealing layer has a region in which the visible light transmittance gradually increases on the side opposite the peripheral edge of the laminated glass.

12. The laminated glass according to any one of claims 1 to 6, further comprising a second concealing layer that is arranged on the second glass plate side of the heating function layer in a cross-sectional view and overlaps with the heating function layer in a planar view.

13. The laminated glass according to claim 12, wherein the first concealing layer, the heating function layer, and the second concealing layer are laminated in contact with each other.

14. The laminated glass according to claim 12, wherein the second concealing layer is a colored ceramic layer, a colored interlayer, or a colored film.

15. The laminated glass according to claim 12, wherein the second concealing layer has a region in which the visible light transmittance gradually increases on the side opposite the peripheral edge of the laminated glass.

16. The laminated glass according to any one of claims 1 to 6, wherein the optical reflective layer has a visible light reflectance of 10% or more when P-polarized visible light is incident at an incident angle of 55 degrees or more and 75 degrees or less.

17. The laminated glass according to any one of claims 1 to 6, wherein the optical reflective layer has a visible light reflectance of 18% or more when S-polarized visible light is incident at an incident angle of 55 degrees or more and 75 degrees or less.

18. The laminated glass according to any one of claims 1 to 6, wherein the optically reflective layer is disposed on a surface of the first glass sheet opposite to the intermediate film.

Images