Vehicle glass and method for manufacturing vehicle glass

Abstract

The present invention appropriately transmits far-infrared rays and ensures a design property. A far-infrared ray transmitting member (20) includes a base material (30) that transmits far-infrared rays, and a functional film (31) that is formed on the base material (30), wherein the reflectance dispersion at 1 nm intervals of light with wavelengths of 360-830 nm is 30 or less, the reflectance of visible light stipulated in JIS R 3106 is 25% or less, and the average transmittance of light with wavelengths of 8-12 μm is 50% or more.

Description

[Technical Field]

[0001] The present invention relates to a far-infrared ray transmitting member and a method for manufacturing the far-infrared ray transmitting member. [Background technology]

[0002] For example, when a far-infrared sensor is mounted on a vehicle, a far-infrared transmitting member having an anti-reflection film formed thereon is sometimes provided to suppress reflection of far-infrared rays and increase the amount of transmitted light so that far-infrared rays are appropriately incident on the far-infrared sensor. For example, Patent Document 1 describes the use of an infrared-transmitting film having an extinction coefficient of 0.4 or less in the far-infrared range in an on-vehicle imaging device. Furthermore, Non-Patent Documents 1 and 2 describe the formation of a NiO film as an infrared anti-reflection film on a Si substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-151408 [Non-Patent Document 1] Hyun Bin Shim et al., Controlling the infrared optical properties of rf-sputtered NiO films for application of infrared window, Infrared Physics and Technology 72(2015), 135-139 [Non-patent document 2] Hyun Bin Shim et al., Nickel oxide film as an AR coating of Si window for IRsensor packaging, Infrared Technology and Applications XXXIX, Proc.of SPIE Vol,8704 870420-1 Summary of the Invention [Problem to be solved by the invention]

[0004] From the viewpoint of design, it is preferable that such a far-infrared-transmitting member is inconspicuous, for example, when it is provided exposed to the outside. Therefore, there is a demand for a far-infrared-transmitting member that can adequately transmit far-infrared rays while ensuring design.

[0005] An object of the present invention is to provide a far-infrared transmitting member that appropriately transmits far-infrared rays and ensures designability, and a method for manufacturing a far-infrared transmitting member. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the far-infrared transparent member according to the present disclosure is a far-infrared transparent member including a substrate that transmits far-infrared rays and a functional film formed on the substrate, and has a dispersion of reflectance in 1 nm increments for light with wavelengths of 360 nm to 830 nm of 30 or less, a reflectance for visible light specified by JIS R3106 of 25% or less, and an average transmittance for light with wavelengths of 8 μm to 12 μm of 50% or more.

[0007] In order to solve the above-mentioned problems and achieve the object, the method for manufacturing a far-infrared transparent member according to the present disclosure comprises forming a functional film on a substrate that transmits far-infrared rays, and manufacturing a far-infrared transparent member having a dispersion of reflectance in 1-nm increments for light with wavelengths of 360 nm to 830 nm of 30 or less, a reflectance of visible light specified by JIS R3106 of 25% or less, and an average transmittance of light with wavelengths of 8 μm to 12 μm of 50% or more. [Effects of the Invention]

[0008] According to the present invention, far-infrared rays can be transmitted appropriately and design properties can be ensured. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a state in which a vehicle glass according to this embodiment is mounted on a vehicle. [Figure 2]FIG. 2 is a schematic plan view of the vehicle glass 1 according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along the line BB in FIG. [Figure 5] FIG. 5 is a schematic cross-sectional view of a far-infrared ray transmitting member according to this embodiment. [Figure 6] FIG. 6 is a schematic cross-sectional view of a far-infrared transmitting member according to another example of this embodiment. [Figure 7] FIG. 7 is a schematic cross-sectional view of a far-infrared transmitting member according to another example of this embodiment. [Figure 8] FIG. 8 is a graph showing the evaluation results of each example. [Figure 9] FIG. 9 is a graph showing the evaluation results of each example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that the present invention is not limited to these embodiments, and when there are multiple embodiments, the present invention also includes configurations that are made by combining the respective embodiments. Furthermore, numerical values include the range of rounding.

[0011] (vehicle) FIG. 1 is a schematic diagram showing a state in which a vehicle glass according to this embodiment is mounted on a vehicle. As shown in FIG. 1, the vehicle glass 1 according to this embodiment is mounted on a vehicle V. The vehicle glass 1 is a window member that is applied to the windshield of the vehicle V. That is, the vehicle glass 1 is used as the front window of the vehicle V, in other words, as a windshield. A far-infrared camera CA1 and a visible light camera CA2 are mounted inside (interior of) the vehicle V. Note that the inside (interior of) the vehicle V refers to, for example, the interior of the vehicle where the driver's seat is located.

[0012] The vehicle glass 1, the far-infrared camera CA1, and the visible light camera CA2 constitute a camera unit 100 according to this embodiment. The far-infrared camera CA1 is a camera that detects far-infrared rays and captures a thermal image of the exterior of the vehicle V by detecting far-infrared rays from outside the vehicle V. The visible light camera CA2 is a camera that detects visible light and captures an image of the exterior of the vehicle V by detecting visible light from outside the vehicle V. In addition to the far-infrared camera CA1 and the visible light camera CA2, the camera unit 100 may further include, for example, a LiDAR or a millimeter-wave radar. Here, far-infrared rays refer to, for example, electromagnetic waves with a wavelength in the 8 μm to 13 μm range, and visible light refers to, for example, electromagnetic waves with a wavelength in the 360 nm to 830 nm range. Here, 8 μm to 13 μm and 360 nm to 830 nm refer to 8 μm or more and 13 μm or less, and 360 nm or more and 830 nm or less, respectively, and the same applies hereinafter. The far infrared rays may be electromagnetic waves having a wavelength in the range of 8 μm to 12 μm.

[0013] (vehicle glass) FIG. 2 is a schematic plan view of a vehicle glass 1 according to the first embodiment. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. FIG. 4 is a cross-sectional view taken along cross section BB in FIG. 2. As shown in FIG. 2, hereinafter, the upper edge of the vehicle glass 1 will be referred to as upper edge portion 1a, the lower edge as lower edge portion 1b, one side edge as side edge portion 1c, and the other side edge as side edge portion 1d. The upper edge portion 1a is an edge portion located on the upper side in the vertical direction when the vehicle glass 1 is mounted on a vehicle V. The lower edge portion 1b is an edge portion located on the lower side in the vertical direction when the vehicle glass 1 is mounted on a vehicle V. The side edge portion 1c is an edge portion located on one side when the vehicle glass 1 is mounted on a vehicle V. The side edge portion 1d is an edge portion located on the other side when the vehicle glass 1 is mounted on a vehicle V.

[0014] Hereinafter, among directions parallel to the surface of the vehicle glass 1, the direction from the upper edge 1a to the lower edge 1b is referred to as the Y direction, and the direction from the side edge 1c to the side edge 1d is referred to as the X direction. In this embodiment, the X direction and the Y direction are perpendicular to each other. The direction perpendicular to the surface of the vehicle glass 1, i.e., the thickness direction of the vehicle glass 1, is referred to as the Z direction. For example, when the vehicle glass 1 is installed in a vehicle V, the Z direction is the direction from the exterior side to the interior side of the vehicle V. The X direction and the Y direction run along the surface of the vehicle glass 1, but if the surface of the vehicle glass 1 is curved, for example, they may be directions tangent to the surface of the vehicle glass 1 at the center point O of the vehicle glass 1. The center point O is the center position of the vehicle glass 1 when the vehicle glass 1 is viewed from the Z direction.

[0015] The vehicle glass 1 is formed with a light-transmitting region A1 and a light-shielding region A2. The light-transmitting region A1 is a region that occupies the central part of the vehicle glass 1 when viewed from the Z direction. The light-transmitting region A1 is a region that ensures the driver's field of vision. The light-transmitting region A1 is a region that transmits visible light. The light-shielding region A2 is a region that is formed around the light-transmitting region A1 when viewed from the Z direction. The light-shielding region A2 is a region that blocks visible light. Within the light-shielding region A2a, which is the portion of the light-shielding region A2 on the upper edge portion 1a side, a far-infrared light-transmitting region B and a visible light-transmitting region C are formed.

[0016] The far-infrared transmitting region B is a region that transmits far-infrared rays and is a region where the far-infrared camera CA1 is provided. That is, the far-infrared camera CA1 is provided at a position that overlaps with the far-infrared transmitting region B when viewed from the optical axis direction of the far-infrared camera CA1. The visible light transmitting region C is a region that transmits visible light and is a region where the visible light camera CA2 is provided. That is, the visible light camera CA2 is provided at a position that overlaps with the visible light transmitting region C when viewed from the optical axis direction of the visible light camera CA2.

[0017] In this way, the light-shielding region A2 has the far-infrared-transmitting region B and the visible-light-transmitting region C formed therein, so that the light-shielding region A2 blocks far-infrared rays except in the region where the far-infrared-transmitting region B is formed, and blocks visible light except in the region where the visible-light-transmitting region C is formed. The light-shielding region A2a is formed around the far-infrared-transmitting region B and the visible-light-transmitting region C. Providing the light-shielding region A2a around the periphery in this way is preferable because it protects the various sensors from sunlight. It is also preferable from the standpoint of design because the wiring of the various sensors is not visible from outside the vehicle.

[0018] As shown in Fig. 3, the vehicle glass 1 includes a glass substrate 12 (first glass substrate), a glass substrate 14 (second glass substrate), an intermediate layer 16, and a light-shielding layer 18. The vehicle glass 1 has the glass substrate 12, the intermediate layer 16, the glass substrate 14, and the light-shielding layer 18 laminated in this order in the Z direction. The glass substrate 12 and the glass substrate 14 are fixed (bonded) to each other via the intermediate layer 16.

[0019] The glass substrates 12, 14 may be made of, for example, soda-lime glass, borosilicate glass, or aluminosilicate glass. The intermediate layer 16 is an adhesive layer that bonds the glass substrates 12 and 14 together. The intermediate layer 16 may be made of, for example, a polyvinyl butyral (hereinafter also referred to as PVB) modified material, an ethylene-vinyl acetate copolymer (EVA)-based material, a urethane resin material, or a vinyl chloride resin material. More specifically, the glass substrate 12 includes one surface 12A and another surface 12B, and the other surface 12B is in contact with one surface 16A of the intermediate layer 16 and fixed (adhered) to the intermediate layer 16. The glass substrate 14 includes one surface 14A and another surface 14B, and the one surface 14A is in contact with the other surface 16B of the intermediate layer 16 and fixed (adhered) to the intermediate layer 16. In this way, the vehicle glass 1 is a laminated glass in which the glass substrate 12 and the glass substrate 14 are laminated together. However, the vehicle glass 1 is not limited to a laminated glass, and may be configured to include, for example, only one of the glass substrate 12 and the glass substrate 14. In this case, the intermediate layer 16 may not be provided. Hereinafter, when there is no need to distinguish between the glass substrates 12 and 14, they will be referred to as the glass substrate 10.

[0020] The light-shielding layer 18 includes one surface 18A and the other surface 18B, and the one surface 18A is in contact with and fixed to the other surface 14B of the glass substrate 14. The light-shielding layer 18 is a layer that blocks visible light. For example, a ceramic light-shielding layer or a light-shielding film can be used as the light-shielding layer. For example, a ceramic layer made of a conventionally known material, such as a black ceramic layer, can be used as the ceramic light-shielding layer. For example, a light-shielding polyethylene terephthalate (PET) film, a light-shielding polyethylene naphthalate (PEN) film, a light-shielding polymethyl methacrylate (PMMA) film, etc. can be used as the light-shielding film.

[0021] In the present embodiment, the side of the vehicle glass 1 on which the light-shielding layer 18 is provided is the interior side of the vehicle V (inside of the vehicle), and the side on which the glass substrate 12 is provided is the exterior side of the vehicle V (outside of the vehicle), but this is not limiting, and the light-shielding layer 18 may be on the exterior side of the vehicle V. When the vehicle glass 1 is configured as a laminated glass of the glass substrates 12, 14, the light-shielding layer 18 may be formed between the glass substrate 12 and the glass substrate 14.

[0022] (shading area) The light-shielding region A2 is formed by providing the light-shielding layer 18 on the glass base 10. That is, the light-shielding region A2 is a region in which the glass base 10 is provided with the light-shielding layer 18. That is, the light-shielding region A2 is a region in which the glass base 12, the intermediate layer 16, the glass base 14, and the light-shielding layer 18 are laminated. On the other hand, the light-transmitting region A1 is a region in which the glass base 10 is not provided with the light-shielding layer 18. That is, the light-transmitting region A1 is a region in which the glass base 12, the intermediate layer 16, and the glass base 14 are laminated, and the light-shielding layer 18 is not laminated.

[0023] (far infrared transmission area) As shown in FIG. 3 , the vehicle glass 1 has an opening 19 formed therein, penetrating from one surface (here, surface 12A) to the other surface (here, surface 14B) in the Z direction. A far-infrared-transmitting member 20 is provided within the opening 19. The region where the opening 19 is formed and the far-infrared-transmitting member 20 is provided is the far-infrared-transmitting region B. That is, the far-infrared-transmitting region B is a region where the opening 19 and the far-infrared-transmitting member 20 disposed within the opening 19 are provided. Because the light-shielding layer 18 does not transmit far-infrared rays, the far-infrared-transmitting region B is not provided with the light-shielding layer 18. That is, the far-infrared-transmitting region B does not have the glass base 12, the intermediate layer 16, the glass base 14, and the light-shielding layer 18, and the far-infrared-transmitting member 20 is provided in the formed opening 19. The far-infrared-transmitting member 20 will be described later.

[0024] (Visible light range) 4, similar to the light-transmitting region A1, the visible light transmitting region C is a region in the Z direction where the glass base 10 does not include the light-shielding layer 18. That is, the visible light transmitting region C is a region where the glass base 12, the intermediate layer 16, and the glass base 14 are laminated, and where the light-shielding layer 18 is not laminated.

[0025] As shown in FIG. 2, the visible light transmitting region C is preferably located near the far-infrared light transmitting region B. Specifically, the center of the far-infrared light transmitting region B as viewed from the Z direction is defined as center point OB, and the center of the visible light transmitting region C as viewed from the Z direction is defined as center point OC. If the shortest distance between the far-infrared light transmitting region B (opening 19) and the visible light transmitting region C as viewed from the Z direction is defined as distance L, distance L is preferably greater than 0 mm and less than or equal to 100 mm, and more preferably greater than or equal to 10 mm and less than or equal to 80 mm. Positioning the visible light transmitting region C within this range relative to the far-infrared light transmitting region B enables the far-infrared camera CA1 and the visible light camera CA2 to capture images at nearby positions, while suppressing the amount of perspective distortion in the visible light transmitting region C, allowing the visible light camera CA2 to capture appropriate images. Capturing images at nearby positions with the far-infrared camera CA1 and the visible light camera CA2 reduces the load when processing data obtained from each camera and also optimizes the routing of power and signal cables.

[0026] As shown in Fig. 2, the visible light transmitting region C and the far-infrared transmitting region B are preferably positioned side by side in the X direction. That is, the visible light transmitting region C is preferably not positioned on the Y direction side of the far-infrared transmitting region B, but is preferably aligned with the far-infrared transmitting region B in the X direction. By arranging the visible light transmitting region C next to the far-infrared transmitting region B in the X direction, the visible light transmitting region C can be positioned near the upper edge portion 1a. Therefore, the driver's field of view in the light transmitting region A1 can be appropriately secured.

[0027] (Far-infrared transmitting material) The far-infrared transparent member 20 provided in the far-infrared transparent region B will be specifically described below. FIG. 5 is a schematic cross-sectional view of the far-infrared transparent member according to this embodiment. As shown in FIG. 5, the far-infrared transparent member 20 has a substrate 30 and a functional film 31 formed on the substrate 30. In this embodiment, the far-infrared transparent member 20 has the functional film 31 formed on both one surface 30a and the other surface 30b of the substrate 30. The surface 30a is the surface that faces the interior of the vehicle when mounted on the vehicle glass 1, and the surface 30b is the surface that faces the exterior of the vehicle when mounted on the vehicle glass 1. However, the far-infrared transparent member 20 is not limited to having the functional film 31 formed on both surfaces 30a and 30b of the substrate 30, and may have the functional film 31 formed on at least one of the surfaces 30a and 30b. Of the surfaces 30a and 30b, the functional film 31 is preferably formed on at least the exterior-facing surface 30b. That is, it can be said that the surface 30a of the base material 30 does not necessarily need to have a film formed thereon, or the functional film 31 or a film other than the functional film 31 may be formed thereon.

[0028] As described above, in this embodiment, the far-infrared ray transmitting member 20 is provided in the light-shielding area A2 of the vehicle glass 1, which is a window member of the vehicle V, but is not limited thereto and may be provided in any exterior member of the vehicle V, such as an exterior member for a pillar of the vehicle V. Moreover, the far-infrared ray transmitting member 20 is not limited to being provided in the vehicle V, and may be used for any purpose.

[0029] (base material) The base material 30 is a member that can transmit far-infrared rays. The base material 30 preferably has an internal transmittance of 50% or more, more preferably 60% or more, and even more preferably 70% or more with respect to light (far-infrared rays) having a wavelength of 10 μm. Further, the base material 30 preferably has an average internal transmittance of 50% or more, more preferably 60% or more, and even more preferably 70% or more with respect to light (far-infrared rays) having a wavelength of 8 μm to 12 μm. When the internal transmittance of the base material 30 at 10 μm and the average internal transmittance at 8 μm to 12 μm are within this numerical range, far-infrared rays can be appropriately transmitted, and for example, the performance of the far-infrared camera CA1 can be fully exhibited. Here, the average internal transmittance is the average value of the internal transmittances with respect to light of each wavelength in the wavelength band (here, from 8 μm to 12 μm).

[0030] The internal transmittance of the base material 30 is the transmittance excluding the surface reflection loss on the incident side and the exit side, which is well-known in the technical field, and its measurement may be performed by a commonly used method. The measurement is performed, for example, as follows.

[0031] Prepare a pair of flat samples (the first sample and the second sample) made of base materials having the same composition and different thicknesses. Both surfaces of the flat sample are planes parallel to each other and optically polished. Let the external transmittance including the surface reflection loss of the first sample be T1, the external transmittance including the surface reflection loss of the second sample be T2, the thickness of the first sample be Td1 (mm), and the thickness of the second sample be Td2 (mm), provided that Td1 < Td2. Then, the internal transmittance τ at a thickness Tdx (mm) can be calculated by the following formula (1).

[0032] τ = exp[-Tdx×(lnT1 - lnT2) / ΔTd] ···(1)

[0033] Note that the external transmittance of infrared rays can be measured, for example, by a Fourier transform infrared spectrometer (manufactured by Thermo Scientific, product name: Nicolet iS10).

[0034] The refractive index of the substrate 30 for light with a wavelength of 10 μm is preferably 1.5 to 4.0, more preferably 2.0 to 4.0, and even more preferably 2.2 to 3.5. Furthermore, the average refractive index of the substrate 30 for light with a wavelength of 8 μm to 12 μm is preferably 1.5 to 4.0, more preferably 2.0 to 4.0, and even more preferably 2.2 to 3.5. Having the refractive index and average refractive index of the substrate 30 within these numerical ranges allows for appropriate transmission of far-infrared light, enabling the performance of, for example, the far-infrared camera CA1 to be fully demonstrated. The average refractive index here refers to the average value of the refractive index for light of each wavelength in the wavelength band (here, 8 μm to 12 μm). The refractive index can be determined, for example, by fitting an optical model using polarization information obtained from an infrared spectroscopic ellipsometer (IR-VASE-UT, manufactured by J.A. Woollam) and a spectral transmission spectrum obtained from a Fourier transform infrared spectrometer.

[0035] The thickness d0 of the substrate 30 is preferably 0.5 mm to 5 mm, more preferably 1 mm to 4 mm, and even more preferably 1.5 mm to 3 mm. When the thickness d0 is within this range, the substrate 30 can adequately transmit far-infrared rays while maintaining strength. The thickness d0 can also be considered as the length in the Z direction from the surface 30a to the surface 30b of the substrate 30.

[0036] The material of the substrate 30 is not particularly limited, but examples thereof include Si, Ge, ZnS, and chalcogenide glass. It is preferable that the substrate 30 contains at least one material selected from the group consisting of Si, Ge, ZnS, and chalcogenide glass. By using such a material for the substrate 30, far infrared rays can be transmitted appropriately. A preferred composition of the chalcogenide glass is: In atomic % Ge+Ga;7%~25% Sb: 0%~35% Bi: 0%~20%, Zn: 0%~20%, Sn: 0%~20%, Si: 0% to 20%, La: 0%~20%, S+Se+Te; 55%~80% Ti: 0.005%~0.3%, Li+Na+K+Cs; 0%~20% The composition contains 0% to 20% of F+Cl+Br+I. This glass preferably has a glass transition point (Tg) of 140°C to 550°C.

[0037] It is more preferable to use Si or ZnS as the material for the base material 30.

[0038] (functional membrane) The functional film 31 is formed on the substrate 30 and is a film for suppressing reflection of visible light and far infrared rays.

[0039] 5, the functional film 31 according to this embodiment includes a visible light absorbing layer 32, a high refractive index layer 36, and a low refractive index layer 38. In the example of FIG. 5, the high refractive index layer 36 and the low refractive index layer 38 are alternately stacked between the substrate 30 and the visible light absorbing layer 32. That is, in the functional film 31, the visible light absorbing layer 32 is formed on the outermost side (the side farthest from the substrate 30). However, the visible light absorbing layer 32 does not necessarily have to be formed on the outermost side in the functional film 31, and the high refractive index layer 36 and the low refractive index layer 38 may be formed outside the visible light absorbing layer 32.

[0040] In the example of FIG. 5 , the functional film 31 is formed by stacking a high-refractive index layer 36, a low-refractive index layer 38, and a visible-light absorbing layer 32 on the substrate 30 in this order, facing away from the substrate 30. Hereinafter, the surface of the high-refractive index layer 36 facing away from the substrate 30 will be referred to as surface 36a, the surface of the high-refractive index layer 36 facing the substrate 30 will be referred to as surface 36b, the surface of the low-refractive index layer 38 facing away from the substrate 30 will be referred to as surface 38a, the surface of the low-refractive index layer 38 facing the substrate 30 will be referred to as surface 38b, the surface of the visible-light absorbing layer 32 facing away from the substrate 30 will be referred to as surface 32a, and the surface of the visible-light absorbing layer 32 facing the substrate 30 will be referred to as surface 32b. That is, in the example of FIG. 5 , surface 36b of the high-refractive index layer 36 is surface 31b of the functional film 31 facing the substrate 30, and surface 32a of the visible-light absorbing layer 32 is surface 31b of the functional film 31 facing the substrate 30. However, in a configuration including the visible light absorbing layer 32, the high refractive index layer 36, and the low refractive index layer 38, the layer formed closest to the substrate 30 is not limited to the high refractive index layer 36, and may be, for example, the low refractive index layer 38. For example, the low refractive index layer 38, the high refractive index layer 36, and the visible light absorbing layer 32 may be laminated in this order in the direction away from the substrate 30.

[0041] 5, the functional film 31 has a configuration in which one high-refractive index layer 36, one low-refractive index layer 38, and one visible-light absorbing layer 32 are laminated. However, the present invention is not limited to this configuration, and at least one of the high-refractive index layer 36 and the low-refractive index layer 38 may be laminated in multiple layers. For example, the far-infrared transmitting member 20 may have a configuration in which multiple high-refractive index layers 36 and multiple low-refractive index layers 38 are alternately laminated from the substrate 30 toward a direction away from the substrate 30, with the visible-light absorbing layer 32 being the outermost layer (the side farthest from the substrate 30). That is, the layers may be laminated in the order of the substrate 30, the high-refractive index layer 36, the low-refractive index layer 38, the high-refractive index layer 36, the low-refractive index layer 38, and the visible-light absorbing layer 32. The far-infrared transmitting member 20 may have a configuration in which multiple high-refractive index layers 36 and multiple low-refractive index layers 38 are alternately laminated from the substrate 30 toward a direction away from the substrate 30, with the visible-light absorbing layer 32 being the outermost layer. That is, the substrate 30, the low refractive index layer 38, the high refractive index layer 36, the low refractive index layer 38, and the visible light absorbing layer 32 may be laminated in this order.

[0042] Alternatively, the functional film 31 may have a layer configuration including the visible light absorbing layer 32 and the high refractive index layer 36 but not the low refractive index layer 38. In this case, the visible light absorbing layer 32 functions as an intermediate refractive index layer (low refractive index layer) having a refractive index lower than that of the high refractive index layer 36. The functional film 31 may be formed on the substrate 30 with the high refractive index layer 36 and the visible light absorbing layer 32 stacked one layer at a time in the direction away from the substrate 30, or with the visible light absorbing layer 32 and the high refractive index layer 36 stacked one layer at a time. Alternatively, the functional film 31 may be formed with at least one of the visible light absorbing layer 32 and the high refractive index layer 36 stacked in multiple layers. In this case, for example, the functional film 31 may be formed by alternately stacking visible light absorbing layers 32 and high refractive index layers 36, and may be stacked on the substrate 30 in the order of high refractive index layer 36, visible light absorbing layer 32, high refractive index layer 36, ..., visible light absorbing layer 32, in the direction away from the substrate 30, or may be stacked in the order of visible light absorbing layer 32, high refractive index layer 36, ..., visible light absorbing layer 32.

[0043] Alternatively, the functional film 31 may have a layer configuration including the visible light absorbing layer 32 and the low refractive index layer 38 but not the high refractive index layer 36. In this case, the visible light absorbing layer 32 functions as an intermediate refractive index layer (high refractive index layer) having a refractive index higher than that of the low refractive index layer 38. The functional film 31 may be formed on the substrate 30 with the visible light absorbing layer 32 and the low refractive index layer 38 stacked one layer at a time in the direction away from the substrate 30, or with the low refractive index layer 38 and the visible light absorbing layer 32 stacked one layer at a time. Alternatively, the functional film 31 may be formed with at least one of the visible light absorbing layer 32 and the low refractive index layer 38 stacked multiple times. In this case, for example, the functional film 31 may be formed by alternately stacking visible light absorbing layers 32 and low refractive index layers 38, and may be stacked on the substrate 30 in the order of visible light absorbing layer 32, low refractive index layer 38, visible light absorbing layer 32, ..., low refractive index layer 38, in the direction away from the substrate 30, or may be stacked in the order of low refractive index layer 38, visible light absorbing layer 32, ..., low refractive index layer 38.

[0044] When multiple layers are laminated as described above, the layer of the functional film 31 closest to the substrate 30 is the visible light absorbing layer 32, the high refractive index layer 36, or the low refractive index layer 38, taking into consideration the refractive index of the substrate and adhesion to the substrate. By laminating multiple visible light absorbing layers 32, high refractive index layers 36, and low refractive index layers 38 in this manner, it is possible to suppress the reflectance of light in a wider wavelength band.

[0045] Furthermore, the functional film 31 does not necessarily have to include both the high-refractive index layer 36 and the low-refractive index layer 38, and can be characterized as having at least one visible light-absorbing layer 32. That is, the functional film 31 may be a single-layer film consisting of a single visible light-absorbing layer 32, or it may be a multilayer film laminated with at least one of the high-refractive index layer 36 and the low-refractive index layer 38. By using the functional film 31 as an anti-reflection film with a multilayer structure, it becomes easy to achieve low reflectance over a wide wavelength range by utilizing the light interference effect caused by interfacial reflection at each interface. In the multilayer functional film 31, the visible light-absorbing layer 32 is preferably positioned outermost from the substrate 30.

[0046] Furthermore, the functional film 31 formed on the vehicle interior side of the substrate 30 may have a different layer structure from the functional film 31 formed on the vehicle exterior side.

[0047] (visible light absorbing layer) The refractive index of the visible light absorbing layer 32 for light with a wavelength of 550 nm (visible light) is preferably 1.5 to 4.0, more preferably 1.7 to 3.5, and even more preferably 2.0 to 2.5. The average refractive index of the visible light absorbing layer 32 for light with a wavelength of 380 nm to 780 nm is preferably 1.5 to 4.0, more preferably 1.7 to 3.5, and even more preferably 2.0 to 2.5. Having the refractive index and average refractive index for visible light of the visible light absorbing layer 32 within these numerical ranges suppresses reflection of visible light, making the far-infrared transmitting member 20 less noticeable. The refractive index for light with a wavelength of 550 nm can be determined by fitting an optical model using, for example, polarization information obtained by a spectroscopic ellipsometer (JA Woollam M-2000) and spectral transmittance measured in accordance with JIS R3106.

[0048] The visible light absorbing layer 32 preferably has an extinction coefficient for light with a wavelength of 550 nm of 0.04 or more, more preferably 0.05 or more, even more preferably 0.06 or more, even more preferably 0.07 or more, even more preferably 0.08 or more, and even more preferably 0.10 or more. The visible light absorbing layer 32 also preferably has an average extinction coefficient for light with a wavelength of 380 nm to 780 nm of 0.04 or more, more preferably 0.05 or more, even more preferably 0.06 or more, even more preferably 0.07 or more, even more preferably 0.08 or more, and even more preferably 0.10 or more. Having the extinction coefficient and average extinction coefficient within these ranges appropriately suppresses reflectance dispersion of visible light, resulting in an appearance that ensures aesthetic design. The average extinction coefficient is the average value of the extinction coefficients for light of each wavelength in the wavelength band (here, 380 nm to 780 nm). The extinction coefficient of light with a wavelength of 550 nm can be determined by fitting an optical model using, for example, polarization information obtained by a spectroscopic ellipsometer and spectral transmittance measured in accordance with JIS R3106.

[0049] The refractive index of the visible light absorbing layer 32 for light with a wavelength of 10 μm (far-infrared radiation) is preferably 1.5 to 4.0, more preferably 1.7 to 3.0, and even more preferably 2.0 to 2.5. The average refractive index of the visible light absorbing layer 32 for light with a wavelength of 8 μm to 12 μm is preferably 1.5 to 4.0, more preferably 1.7 to 3.0, and even more preferably 2.0 to 2.5. Having the refractive index and average refractive index for far-infrared radiation within these numerical ranges of the visible light absorbing layer 32 suppresses reflection of far-infrared radiation and allows appropriate transmission of far-infrared radiation. The refractive index for light with a wavelength of 8 μm to 12 μm can be determined by fitting an optical model using, for example, polarization information obtained from an infrared spectroscopic ellipsometer (IR-VASE-UT, manufactured by J.A. Woollam) and a spectral transmission spectrum obtained from a Fourier transform infrared spectrometer (Nicolet iS10, manufactured by ThermoScientific).

[0050] The visible light absorbing layer 32 is capable of transmitting far-infrared rays. The visible light absorbing layer 32 preferably has an extinction coefficient of 0.1 or less, preferably 0.05 or less, and more preferably 0.02 or less, for light with a wavelength of 10 μm. The visible light absorbing layer 32 preferably has an average extinction coefficient of 0.1 or less, preferably 0.05 or less, and more preferably 0.02 or less, for light with a wavelength of 8 μm to 12 μm. When the extinction coefficient and average extinction coefficient are within these ranges, far-infrared rays can be appropriately transmitted. The extinction coefficient for light with a wavelength of 8 μm to 12 μm can be determined by fitting an optical model using, for example, polarization information obtained by an infrared spectroscopic ellipsometer and a spectral transmission spectrum obtained by a Fourier transform infrared spectrometer.

[0051] The thickness d1 of the visible light absorption layer 32 is preferably 0.1 μm or more and 2.0 μm or less, more preferably 0.5 μm or more and 1.5 μm or less, and even more preferably 0.8 μm or more and 1.4 μm or less. Having the thickness d1 within this range makes it possible to appropriately suppress reflection of far-infrared rays while also appropriately suppressing reflection and dispersion of visible light. The thickness d1 can also be considered as the length in the Z direction from the surface 32a of the visible light absorption layer 32 to the opposite surface 32b.

[0052] The visible light absorbing layer 32 may be made of any material, but preferably contains a metal oxide as its main component. Here, the term "main component" may mean that the content of the metal oxide in the entire visible light absorbing layer 32 is 50 mass % or more. Examples of metal oxides used in the visible light absorbing layer 32 include nickel oxide (NiO x ), copper oxide (CuO x ), and manganese oxide (MnO x The visible light absorbing layer 32 is preferably made of NiO. x , CuO x , and MnO x The visible light absorbing layer 32 preferably contains at least one material selected from the group consisting of NiO x The main component is CuO x and MnO x It is preferable that the main component is at least one material selected from the group consisting of: Nickel oxide, copper oxide, and manganese oxide. Nickel oxide, copper oxide, and manganese oxide are known to have a variety of compositions depending on the valence of nickel, copper, and manganese, and x can take any value between 0.5 and 2. The valence does not have to be single, and two or more valences may be mixed. In this embodiment, NiO x It is preferable to use NiO as the x It is preferable to use CuO as the x However, the material of the visible light absorption layer 32 is not limited to these and may be any material, such as diamond-like carbon.

[0053] (high refractive index layer) The high refractive index layer 36 is a film that is laminated with the visible light absorbing layer 32 and the low refractive index layer 38 and suppresses reflection of far infrared rays. In this embodiment, the high refractive index layer 36 is laminated closer to the substrate 30 than the visible light absorbing layer 32, and in the example of Fig. 5, it is provided between the substrate 30 and the low refractive index layer 38. If the low refractive index layer 38 is not formed, the high refractive index layer 36 will be provided between the substrate 30 and the visible light absorbing layer 32.

[0054] The high refractive index layer 36 is a film with a high refractive index for far-infrared rays, and its refractive index for light with a wavelength of 10 μm is higher than that of the visible light absorption layer 32, preferably from 2.5 to 4.5, more preferably from 3.0 to 4.5, and even more preferably from 3.3 to 4.3. The high refractive index layer 36 also has an average refractive index for light with a wavelength of 8 μm to 12 μm higher than that of the visible light absorption layer 32, preferably from 2.5 to 4.5, more preferably from 3.0 to 4.5, and even more preferably from 3.3 to 4.3. When the refractive index and average refractive index of the high refractive index layer 36 are within these numerical ranges, the high refractive index layer 36 functions appropriately as a high refractive index film, and can appropriately suppress reflection of far-infrared rays.

[0055] The high refractive index layer 36 is capable of transmitting far infrared rays. The high refractive index layer 36 preferably has an extinction coefficient of 0.05 or less, more preferably 0.02 or less, and more preferably 0.01 or less, for light with a wavelength of 10 μm. The high refractive index layer 36 preferably has an average extinction coefficient of 0.05 or less, more preferably 0.02 or less, and more preferably 0.01 or less, for light with a wavelength of 8 μm to 12 μm. When the extinction coefficient and average extinction coefficient are within these ranges, far infrared rays can be transmitted appropriately.

[0056] Furthermore, the thickness d2 of the high refractive index layer 36 is preferably 0.1 μm or more and 2.0 μm or less, more preferably 0.2 μm or more and 1.5 μm or less, and even more preferably 0.3 μm or more and 1.2 μm or less. When the thickness d2 is within this range, reflection of far infrared rays can be appropriately suppressed. Note that the thickness d2 can also be considered as the length in the Z direction from the surface 36a of the high refractive index layer 36 to the opposite surface 36b.

[0057] The high refractive index layer 36 may be made of any material, but preferably contains at least one material selected from the group consisting of Si and Ge as its main component.

[0058] (low refractive index layer) The low refractive index layer 38 is a film laminated with the visible light absorbing layer 32 and the high refractive index layer 36, and suppresses reflection of far infrared rays. In this embodiment, the low refractive index layer 38 is laminated closer to the substrate 30 than the visible light absorbing layer 32, and in the example of Fig. 5, it is provided between the high refractive index layer 36 and the visible light absorbing layer 32. If the high refractive index layer 36 is not formed, the low refractive index layer 38 will be provided between the substrate 30 and the visible light absorbing layer 32.

[0059] The low-refractive index layer 38 is a film with a low refractive index for far-infrared rays, and its refractive index for light with a wavelength of 10 μm is lower than that of the visible light absorption layer 32, preferably from 0.8 to 2.0, more preferably from 1.0 to 1.7, and even more preferably from 1.0 to 1.5. The low-refractive index layer 38 also has an average refractive index for light with a wavelength of 8 μm to 12 μm lower than that of the visible light absorption layer 32, preferably from 0.8 to 2.0, more preferably from 1.0 to 1.7, and even more preferably from 1.0 to 1.5. When the refractive index and average refractive index of the low-refractive index layer 38 are within these numerical ranges, the low-refractive index layer 38 functions appropriately as a low-refractive index film, and can appropriately suppress reflection of far-infrared rays.

[0060] The low refractive index layer 38 is capable of transmitting far infrared rays. The low refractive index layer 38 preferably has an extinction coefficient of 0.05 or less, more preferably 0.02 or less, and more preferably 0.01 or less, for light with a wavelength of 10 μm. The low refractive index layer 38 preferably has an average extinction coefficient of 0.05 or less, more preferably 0.02 or less, and more preferably 0.01 or less, for light with a wavelength of 8 μm to 12 μm. When the extinction coefficient and average extinction coefficient are within these ranges, far infrared rays can be transmitted appropriately.

[0061] The thickness d3 of the low refractive index layer 38 is preferably 0.1 μm or more and 2.0 μm or less, more preferably 0.2 μm or more and 1.7 μm or less, and even more preferably 0.3 μm or more and 1.5 μm or less. Having the thickness d3 within this range allows for appropriate suppression of reflection of far infrared rays. The thickness d3 can also be considered as the length in the Z direction from the surface 38a of the low refractive index layer 38 to the opposite surface 38b.

[0062] The low refractive index layer 38 is preferably a film containing an oxide as a main component. More specifically, the low refractive index layer 38 preferably contains MgO as a main component of the oxide. The low refractive index layer 38 preferably has an MgO content of 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, and even more preferably 85% by mass or more and 100% by mass or less, based on the entire low refractive index layer 38. When the MgO content of the low refractive index layer 38 is within this range, the low refractive index layer 38 can appropriately transmit far infrared rays, have a low refractive index for far infrared rays, and appropriately suppress reflection of far infrared rays.

[0063] The low refractive index layer 38 may contain a secondary component other than the oxide (here, MgO) that is the main component. The secondary component is preferably an oxide that transmits infrared rays, such as NiO. x , CuO x , ZnO, ZrO2, Bi2O3, and Y2O3.

[0064] (Characteristics of far-infrared transmitting materials) As described above, the far-infrared-transmitting member 20 is formed by forming the functional film 31 having at least one visible light absorbing layer 32 on the surface of the base material 30. By forming the functional film 31 having the visible light absorbing layer 32 on the surface of the base material 30, the far-infrared-transmitting member 20 appropriately transmits far-infrared rays while suppressing the reflectance and reflectance dispersion of visible light, thereby ensuring designability.

[0065] The far-infrared transmitting member 20 preferably has a transmittance of 50% or more, more preferably 65% or more, and even more preferably 70% or more for light with a wavelength of 10 μm. The far-infrared transmitting member 20 also preferably has an average transmittance of 50% or more, more preferably 65% or more, and even more preferably 70% or more for light with a wavelength of 8 μm to 12 μm. When the transmittance and average transmittance are within these ranges, the function as an infrared transmitting member can be properly exhibited.

[0066] The far-infrared transmitting member 20 preferably has a reflectance of 15% or less for light with a wavelength of 10 μm, more preferably 10% or less, and even more preferably 5% or less. Furthermore, the far-infrared transmitting member 20 preferably has an average reflectance of 15% or less for light with a wavelength of 8 μm to 12 μm, more preferably 10% or less, and even more preferably 5% or less. Having the reflectance and average reflectance within these ranges allows the member to properly function as an infrared transmitting member. The average reflectance is the average value of the reflectance for light of each wavelength in the wavelength band (here, 8 μm to 12 μm). The reflectance can be measured, for example, using a Fourier transform infrared spectrometer (Nicolet iS10, manufactured by ThermoScientific).

[0067] The far-infrared transmitting member 20 has a visible light reflectance of 25% or less, preferably 20% or less, and more preferably 18% or less, as specified in JIS R3106. When the visible light reflectance of the far-infrared transmitting member 20 is in this range, glare is suppressed and designability is ensured.

[0068] The far-infrared transparent member 20 has a dispersion D of the reflectance of light having a wavelength of 360 nm to 830 nm in 1 nm increments of 30 or less, more preferably 25 or less, even more preferably 20 or less, even more preferably 15 or less, even more preferably 10 or less, and even more preferably 5 or less. In other words, the dispersion D refers to the dispersion of the reflectance of the far-infrared transparent member 20 for each of light having a wavelength that differs by 1 nm in the wavelength range of 360 nm to 830 nm (i.e., light having wavelengths of 360 nm, 361 nm, 362 nm, ..., 830 nm). In other words, when the reflectance of the far-infrared transparent member 20 for each of the light beams is denoted by x, the average value of the reflectance of the far-infrared transparent member 20 for each of the light beams having a wavelength that differs by 1 nm increments in the wavelength range of 360 nm to 830 nm is denoted by μ, and the total number of light beams having a wavelength of 360 nm to 830 nm in 1 nm increments is denoted by n, the dispersion D is expressed by the following formula (2): The reflectance of light with wavelengths of 360 nm to 830 nm in 1 nm increments may be measured in accordance with JIS R3106.

[0069]

number

[0070] When the dispersion D falls within the above range, the difference in reflectance for visible light of different wavelengths becomes small, the interference color of the far-infrared transmitting member 20 is suppressed, and the design is ensured.

[0071] 3, the far-infrared transmitting member 20 preferably has an exterior surface formed flush with (continuous with) the exterior surface of the light-shielding region A2. In other words, the exterior surface 20A of the far-infrared transmitting member 20 is attached so as to be continuous with the surface 12A of the glass substrate 12. By having the surface 20A of the far-infrared transmitting member 20 continuous with the surface 12A of the glass substrate 12 in this manner, it is possible to prevent the wiping effect of the wiper from being impaired. It is also possible to prevent steps from impairing the design of the vehicle V and from causing sand and dust to accumulate on the steps. Furthermore, it is preferable that the far-infrared transmitting member 20 is molded to fit the curved surface shape of the vehicle glass 1 to which it is applied. There are no particular limitations on the method for molding the far-infrared transmitting member 20, but polishing or molding can be selected depending on the curved surface shape and the member.

[0072] The shape of the far-infrared transmitting member 20 is not particularly limited, but it is preferably a plate-like shape that matches the shape of the opening 19. That is, for example, if the opening 19 is circular, the far-infrared transmitting member 20 is preferably a disk-like (cylindrical) shape. From the viewpoint of design, the surface shape of the far-infrared transmitting member 20 on the vehicle exterior side may be processed to match the curvature of the outer surface shape of the glass substrate 12. Furthermore, for reasons such as achieving both a wider viewing angle of the far-infrared camera CA1 and improved mechanical properties, the far-infrared transmitting member 20 may be lenticular. This configuration is preferable because far-infrared light can be efficiently collected even if the area of the far-infrared transmitting member 20 is small. In this case, the number of lens-shaped far-infrared transmitting members 20 is preferably one to three, and typically two. Furthermore, it is particularly preferable that the lens-shaped far-infrared transmitting member 20 is pre-aligned and modularized, and is integrated with a housing or bracket that bonds the far-infrared camera CA1 to the vehicle glass 1.

[0073] In the vehicle glass 1 of this embodiment, the area of the opening 19 on the vehicle interior surface is preferably smaller than the area of the opening 19 on the vehicle exterior surface, and the far-infrared transmitting member 20 is also preferably shaped so that the area on the vehicle interior surface is smaller than the area on the vehicle exterior surface accordingly. This configuration improves strength against impacts from the outside of the vehicle. Furthermore, when the vehicle glass 1 of this embodiment is a laminated glass including a glass substrate 12 (vehicle exterior side) and a glass substrate 14 (vehicle interior side), the opening 19 is formed by overlapping the opening 12a of the glass substrate 12 and the opening 14a of the glass substrate 14. In this case, the area of the opening 12a of the glass substrate 12 is made larger than the area of the opening 14a of the glass substrate 14, and a far-infrared transmitting member 20 matching the size of the opening 12a of the glass substrate 12 is disposed within the opening 12a of the glass substrate 12.

[0074] As shown in FIG. 3 , the far-infrared transmitting member 20 preferably has a length D1 of the longest straight line connecting any two points on the vehicle exterior surface, which is 80 mm or less. The length D1 is more preferably 70 mm or less, and even more preferably 65 mm or less. The length D1 is preferably 60 mm or more. As shown in FIG. 3 , the opening 19 in the far-infrared transmitting region B preferably has a length D2 of the longest straight line connecting any two points on the vehicle exterior surface, which is 80 mm or less. The length D2 is more preferably 70 mm or less, and even more preferably 65 mm or less. The length D2 is preferably 60 mm or more. The length D2 can also be considered as the length of the longest straight line connecting any two points on the outer periphery of the opening 19 on the vehicle exterior surface (surface 12A) of the vehicle glass 1. By setting the length D1 of the far-infrared transmitting member 20 and the length D2 of the opening 19 within these ranges, a decrease in the strength of the vehicle glass 1 can be suppressed, and the amount of perspective distortion around the opening 19 can also be suppressed. When the shape of the vehicle exterior surface of the far-infrared transmitting member 20 is circular, the lengths D1 and D2 are lengths corresponding to the diameter of the vehicle exterior surface. Furthermore, the lengths D1 and D2 here refer to the lengths of the vehicle glass 1 when it is mounted on the vehicle V. For example, when the glass is bent into a shape to be mounted on the vehicle V, the lengths D1 and D2 are the lengths after bending. The same applies to the descriptions of dimensions and positions other than the lengths D1 and D2 unless otherwise specified.

[0075] (Method of manufacturing infrared-transmitting member) Next, a method for manufacturing the far-infrared ray transmitting member 20 will be described. When manufacturing the far-infrared ray transmitting member 20, a base material 30 is prepared, and a functional film 31 is formed on the surface of the base material 30. In this embodiment, the functional film 31 is formed on the surface of the base material 30 by sputtering. In this manner, the far-infrared ray transmitting member 20 is manufactured. By forming the functional film 31 by sputtering, it is possible to improve the adhesion of the film. Furthermore, in this manufacturing method, the visible light absorbing layer 32 of the functional film 31 is made of NiO xIn this case, the functional film 31 is formed on the surface of the substrate 30 while heating at 100°C or higher and 300°C or lower. This allows the visible light absorbing layer 32 in the functional film 31 to have an appropriate extinction coefficient for visible light while also improving far-infrared transmittance, thereby achieving an appropriate balance between visible light absorption and far-infrared transmittance. However, the manufacturing method of the far-infrared transmitting member 20 is not limited to this. For example, the functional film 31 may be formed by deposition, rather than by sputtering. Since the functional film 31 is primarily composed of an oxide, the formation method is not limited to deposition, and various methods for formation are possible, making it preferable. In particular, forming the functional film by sputtering can improve productivity and film adhesion. Annealing at 100°C or higher and 300°C or lower may be performed in an air atmosphere.

[0076] The visible light absorbing layer 32 of the functional film 31 is CuO x In this case, once the functional film 31 has been formed on the surface of the substrate 30, it is preferable to perform annealing in an air atmosphere at a temperature of 100°C to 600°C for 0.5 hours to 2 hours. This allows the visible light absorption layer 32 in the functional film 31 to have an appropriate extinction coefficient for visible light while also improving the transmittance of far-infrared rays, thereby achieving an appropriate balance between the absorption of visible light and the transmittance of far-infrared rays.

[0077] (Another example of this embodiment) In this embodiment, the far-infrared ray transmitting member 20 has a configuration in which only the functional film 31 is formed on the base material 30, but is not limited to this. Other examples of the far-infrared ray transmitting member 20 will be described below.

[0078] FIG. 6 is a schematic cross-sectional view of a far-infrared transparent member according to another example of this embodiment. As shown in FIG. 6, the far-infrared transparent member 20 may have a protective film 34 formed on a surface 31a of the functional film 31 opposite the substrate 30. The protective film 34 is formed on the outer surface of the far-infrared transparent member 20, i.e., on the outermost surface exposed to the outside, and protects the functional film 31 from scratches caused by wiping with a wiper or sand and dust. In this embodiment, the protective film 34 is provided on the functional film 31 on the outer side of the vehicle, i.e., on the outer surface of the far-infrared transparent member 20 on the outer side of the vehicle, but not on the inner side. However, the protective film 34 may also be provided on the functional film 31 on the inner side of the vehicle, i.e., on the outer surface of the far-infrared transparent member 20 on the inner side of the vehicle. Note that, for convenience of explanation, the functional film 31 is illustrated as a single layer in the example of FIG. 6, but the functional film 31 is not limited to being a single layer and may have any of the layer configurations described above.

[0079] (protective film) The protective film 34 is preferably a film harder than the functional film 31. Specifically, the protective film 34 preferably has a higher nanoindentation hardness than the functional film 31. By forming such a hard protective film 34 on the surface, the functional film 31 can be appropriately protected from scratches caused by wiping with a wiper or sand and dust. The nanoindentation hardness can be measured, for example, using a nanoindenter (Nanoindenter iMicro, manufactured by Toyo Corporation).

[0080] The protective film 34 preferably has a refractive index of 2.5 or less for light with a wavelength of 550 nm (visible light), more preferably 1.5 to 2.5, and even more preferably 1.7 to 2.4. The protective film 34 also preferably has an average refractive index of 2.5 or less for light with a wavelength of 380 nm to 780 nm, more preferably 1.5 to 2.5, and even more preferably 1.7 to 2.4. When the refractive index and average refractive index of the protective film 34 for visible light fall within these numerical ranges, the combination with the visible light absorbing layer 32 can suppress reflection of visible light, thereby making the far-infrared transmitting member 20 less noticeable. The refractive index of the protective film 34 for light with a wavelength of 550 nm is preferably equal to or less than the refractive index of the visible light absorbing layer 32 for light with a wavelength of 550 nm, and the average refractive index of the protective film 34 for light with a wavelength of 380 nm to 780 nm is preferably equal to or less than the average refractive index of the visible light absorbing layer 32 for light with a wavelength of 380 nm to 780 nm.

[0081] The refractive index of the protective film 34 with respect to light having a wavelength of 10 μm (far-infrared rays) is preferably 0.5 or more and 3.5 or less, more preferably 0.7 or more and 2.5 or less, and even more preferably 1.0 or more and 2.5 or less. The average refractive index of the protective film 34 with respect to light having a wavelength of 8 μm to 12 μm is preferably 0.5 or more and 3.5 or less, more preferably 0.7 or more and 2.5 or less, and even more preferably 1.0 or more and 2.5 or less. When the refractive index and average refractive index of the protective film 34 with respect to far-infrared rays are within these numerical ranges, reflection of far-infrared rays is suppressed and the far-infrared rays can be appropriately transmitted.

[0082] The protective film 34 is capable of transmitting far infrared rays. The protective film 34 preferably has an extinction coefficient of 0.4 or less for light with a wavelength of 10 μm, preferably 0.2 or less, and more preferably 0.1 or less. The protective film 34 preferably has an average extinction coefficient of 0.4 or less for light with a wavelength of 8 μm to 12 μm, preferably 0.2 or less, and more preferably 0.1 or less. When the extinction coefficient and average extinction coefficient are within these ranges, far infrared rays can be transmitted appropriately.

[0083] Furthermore, the thickness d4 of the protective film 34 is preferably 0.01 μm or more and 1 μm or less, more preferably 0.02 μm or more and 0.5 μm or less, and even more preferably 0.05 μm or more and 0.3 μm or less. When the thickness d2 is within this range, reflection of far infrared rays and visible light can be appropriately suppressed. Note that the thickness d2 can also be considered as the length in the Z direction from the surface 34a of the protective film 34 to the opposite surface 34b.

[0084] The material of the protective film 34 is arbitrary, but examples thereof include ZrO2, Al2O3, TiO2, and Si3N. 4、 The protective film 34 preferably contains at least one material selected from the group consisting of AlN and diamond-like carbon. By using such a material, the functional film 31 can be protected appropriately.

[0085] The protective film 34 preferably has water barrier properties to protect the functional film 31 from water. That is, the protective film 34 preferably protects the functional film 31 from water to maintain the appearance of the functional film 31 in the visible light range. The water barrier performance of the protective film 34 varies depending on the material, crystalline structure, and film thickness. Furthermore, from the viewpoint of water barrier properties, the protective film 34 preferably has an amorphous structure.

[0086] The protective film 34 may also be formed by sputtering, similar to the functional film 31, but is not limited to this and may also be formed by vapor deposition, for example.

[0087] Fig. 7 is a schematic cross-sectional view of a far-infrared ray transmitting member according to another example of this embodiment. As shown in Fig. 7, the far-infrared ray transmitting member 20 may have an adhesive film 40 formed between the functional film 31 and the substrate 30. Also in the example of Fig. 7, a protective film 34 as in the example of Fig. 6 may be formed on the outer surface. Note that, although the functional film 31 is illustrated as a single layer in the example of Fig. 7, the functional film 31 is not limited to being a single layer and may have any of the layer configurations described above.

[0088] (adhesive film) The adhesion film 40 is a film that adheres the substrate 30 and the functional film 31 to each other, in other words, a film that improves the adhesive strength between the substrate 30 and the functional film 31. The adhesion film 40 is provided between the substrate 30 and the functional film 31.

[0089] The refractive index of the adhesive film 40 for light with a wavelength of 10 μm (far infrared rays) is preferably 1.0 or more and 4.3 or less, more preferably 1.5 or more and 4.3 or less, and even more preferably 1.5 or more and 3.8 or less. Furthermore, the average refractive index of the adhesive film 40 for light with a wavelength of 8 μm to 12 μm is preferably 1.0 or more and 4.3 or less, more preferably 1.5 or more and 4.3 or less, and even more preferably 1.5 or more and 3.8 or less. When the refractive index and average refractive index of the adhesive film 40 for far infrared rays are within these numerical ranges, reflection of far infrared rays is suppressed and the far infrared rays can be transmitted appropriately.

[0090] The adhesive film 40 is capable of transmitting far-infrared rays. The adhesive film 40 preferably has an extinction coefficient of 0.4 or less for light with a wavelength of 10 μm, more preferably 0.2 or less, and even more preferably 0.1 or less. The adhesive film 40 preferably has an average extinction coefficient of 0.4 or less for light with a wavelength of 8 μm to 12 μm, preferably 0.2 or less, and even more preferably 0.1 or less. When the extinction coefficient and average extinction coefficient are within these ranges, far-infrared rays can be transmitted appropriately.

[0091] Furthermore, the thickness d5 of the adhesive film 40 is preferably 0.05 μm or more and 0.5 μm or less, more preferably 0.05 μm or more and 0.3 μm or less, and even more preferably 0.05 μm or more and 0.1 μm or less. Having the thickness d5 within this range allows for appropriate suppression of reflection of far-infrared rays and visible light. The thickness d5 can also be considered as the length in the Z direction from the surface 40a of the adhesive film 40 to the opposite surface 40b. The thickness d5 of the adhesive film 40 is preferably thinner than the thickness d1 of the visible light absorption layer 32, the thickness d2 of the high refractive index layer 36, and the thickness d3 of the low refractive index layer 38. Having the thickness d5 of the adhesive film 40 thinner than the thicknesses of these layers reduces the impact on optical performance.

[0092] The material of the adhesive film 40 is arbitrary, but examples thereof include Si, Ge, MgO, and NiO. x , CuO x Preferably, the adhesive film 40 contains at least one material selected from the group consisting of ZnS, Al2O3, ZrO2, SiO2, TiO2, ZnO, and Bi2O3. By using such a material, the adhesive film 40 can properly adhere the substrate 30 and the functional film 31 to each other.

[0093] The adhesive film 40 may be formed by sputtering, similar to the functional film 31, but is not limited to this and may be formed by vapor deposition, for example.

[0094] (effect) As described above, the far-infrared transparent member 20 according to this embodiment includes a substrate 30 that transmits far-infrared rays and a functional film 31 formed on the substrate 30. The far-infrared transparent member 20 has a reflectance dispersion D of 30 or less in 1-nm increments for light with wavelengths of 360 nm to 830 nm, a visible light reflectance of 25% or less as defined by JIS R3106, and an average transmittance of 50% or more for light with wavelengths of 8 μm to 12 μm. Here, the far-infrared transparent member is required to appropriately transmit far-infrared rays. Furthermore, when the far-infrared transparent member is installed exposed to the outside, it may be required to be less noticeable from the perspective of design. In contrast, the far-infrared transparent member 20 according to this embodiment has an average transmittance of 50% or more for light with wavelengths of 8 μm to 12 μm, thereby enabling appropriate transmission of far-infrared rays. Furthermore, the far-infrared transparent member 20 has a visible light reflectance of 25% or less, thereby enabling suppression of the intensity of reflected visible light. Furthermore, since the far-infrared transparent member 20 has a dispersion D of 30 or less, the difference in reflectance for visible light of different wavelengths is small, and the visibility of interference colors is suppressed. Therefore, the far-infrared transparent member 20 is less visible to people and less noticeable. In particular, the far-infrared transparent member 20 may be placed within the light-shielding area A2 formed of black ceramics or the like, and it is preferable that the far-infrared transparent member 20 has a high affinity for the light-shielding area A2 in appearance. As described above, the far-infrared transparent member 20 has a low reflectance for visible light and a small dispersion D, and therefore has a high affinity for the light-shielding area A2 in appearance, ensuring designability.

[0095] The far-infrared ray transmitting member 20 preferably has an average transmittance of 65% or more for light with a wavelength of 8 μm to 12 μm. When the far-infrared ray transmitting member 20 has an average transmittance of 65% or more for light with a wavelength of 8 μm to 12 μm, it becomes possible for far-infrared rays to be transmitted appropriately.

[0096] The functional film 31 preferably has one or more visible light absorbing layers 32 mainly composed of a metal oxide. By using a metal oxide as the main component of the visible light absorbing layer 32, it is possible to appropriately reduce the reflectance and dispersion D of visible light while appropriately transmitting far infrared rays, thereby appropriately ensuring the designability of the far-infrared transmitting member 20.

[0097] The visible light absorbing layer 32 is made of NiO x , CuO x , and MnO x It is preferable that the visible light absorbing layer 32 contains, as a main component, at least one material selected from the group consisting of: By using such a material for the visible light absorbing layer 32, it is possible to appropriately reduce the reflectance and dispersion D of visible light while appropriately transmitting far infrared rays, and it is possible to appropriately ensure the design properties of the far-infrared transmitting member 20.

[0098] The functional film 31 preferably has one or more high refractive index layers 36 whose refractive index for light with a wavelength of 10 μm is higher than that of the visible light absorbing layer 32. By providing the high refractive index layer 36 in addition to the visible light absorbing layer 32, the functional film 31 can function appropriately as an anti-reflection film for far infrared rays.

[0099] The functional film 31 preferably has one or more low refractive index layers 38 whose refractive index for light with a wavelength of 10 μm is lower than that of the visible light absorbing layer 32. By providing the low refractive index layer 38 in addition to the visible light absorbing layer 32, the functional film 31 can function appropriately as an anti-reflection film for far infrared rays.

[0100] The functional film 31 preferably has one or more high-refractive index layers 36 having a higher refractive index for light with a wavelength of 10 μm than the visible light absorbing layer 32 and one or more low-refractive index layers 38 having a lower refractive index for light with a wavelength of 10 μm than the visible light absorbing layer 32, and the high-refractive index layers 36 and the low-refractive index layers 38 are alternately stacked between the substrate 30 and the visible light absorbing layer 32. In this way, by alternately stacking the high-refractive index layers 36 and the low-refractive index layers 38 and providing the visible light absorbing layer 32 on the outer side, it is possible to prevent reflection over a wide wavelength range while ensuring the appropriate design of the far-infrared transmitting member 20.

[0101] The high refractive index layer 36 preferably contains at least one material selected from the group consisting of Si and Ge as a main component, and by using such a material for the high refractive index layer 36, it can function appropriately as an anti-reflection film for far infrared rays.

[0102] The low refractive index layer 38 preferably contains MgO as a main component, and by using such a material for the low refractive index layer 38, it can function appropriately as an anti-reflection film for far infrared rays.

[0103] The base material 30 preferably contains at least one material selected from the group consisting of Si, Ge, ZnS, and chalcogenide glass, which allows the base material 30 to adequately transmit far infrared rays.

[0104] It is preferable that the far-infrared-transmitting member 20 further includes a protective film 34 formed on the outer surface and having a refractive index of 2.5 or less for light with a wavelength of 550 nm. By including such a protective film, the far-infrared-transmitting member 20 can appropriately protect the functional film 31 while ensuring the designability of the far-infrared-transmitting member 20.

[0105] The protective film 34 is made of ZrO2, Al2O3, TiO2, and Si3N. 4、 It is preferable that the protective film 34 contains at least one material selected from the group consisting of AlN and diamond-like carbon. By using such a material for the protective film 34, the functional film 31 can be appropriately protected while ensuring the design of the far-infrared transmitting member 20.

[0106] The far-infrared ray transmitting member 20 is preferably mounted on a vehicle. The far-infrared ray transmitting member 20 can appropriately transmit far-infrared rays while ensuring design, and therefore can be appropriately mounted on a vehicle.

[0107] The far-infrared ray transmitting member 20 may be disposed in a window member of a vehicle. The far-infrared ray transmitting member 20 can appropriately transmit far-infrared rays while ensuring design, and therefore can be appropriately mounted on a window member of a vehicle.

[0108] The far-infrared ray transmitting member 20 may be disposed on an exterior member for a vehicle pillar. The far-infrared ray transmitting member 20 can appropriately transmit far-infrared rays while ensuring design, and therefore can be appropriately mounted on an exterior member for a vehicle pillar.

[0109] The far-infrared-transmitting member 20 may be disposed within the light-shielding area A2 of the vehicle exterior member. The far-infrared-transmitting member 20 can appropriately transmit far-infrared rays while ensuring design, and therefore can be appropriately installed within the light-shielding area A2. Furthermore, the far-infrared-transmitting member 20 is preferable because it has a high external affinity with the light-shielding area A2.

[0110] The method for manufacturing a far-infrared transparent member 20 according to this embodiment involves forming a functional film 31 on a substrate 30 that transmits far-infrared rays, and manufacturing a far-infrared transparent member 20 that has a dispersion of reflectance in 1-nm increments of 30 or less for light with wavelengths of 360 nm to 830 nm, a reflectance of 25% or less for visible light as defined by JIS R3106, and an average transmittance of 50% or more for light with wavelengths of 8 μm to 12 μm. This manufacturing method makes it possible to manufacture a far-infrared transparent member 20 that appropriately transmits far-infrared rays and ensures designability.

[0111] In the method for manufacturing the far-infrared transmitting member 20 according to this embodiment, it is preferable to form the functional film 31 by sputtering. By forming the functional film 31 by sputtering, the adhesion of the film can be improved.

[0112] (Example) The present invention will be specifically described below using examples, but the present invention is not limited thereto. Tables 1 to 3 show examples. In Tables 1 to 3, the upper side in the membrane configuration column corresponds to the vehicle exterior side, and the lower side corresponds to the vehicle interior side.

[0113] [Table 1] [Table 2] [Table 3]

[0114] (Example 1) In Example 1, the substrate itself was used as the far-infrared transmitting member. That is, in Example 1, only the substrate was prepared, and no film was formed on the substrate. In Example 1, Si (FZ grade) was used as the substrate. The thickness of the substrate was 2 mm ± 0.1 mm. The thickness was measured with a digital caliper (CD-15CX, manufactured by Mitutoyo Corporation).

[0115] (Example 2) In Example 2, a functional film was formed on each side of the substrate by magnetron sputtering to obtain a far-infrared transmitting member. In Example 2, the substrate was the same Si as in Example 1, and the functional film was a CuO x In Example 2, the thickness of the substrate was the same as in Example 1, and the thickness of the functional film was 1.13 μm.

[0116] In Example 2, first, a Cu target, which is a film-forming raw material, and a substrate were placed facing each other in a magnetron sputtering device. Next, the entire device was evacuated to a vacuum. Then, when the pressure inside the device reached 5 × 10E-4 Pa, Ar gas and oxygen gas were flowed at a total rate of 20 SCCM (standard cc / min, 1 atm (25 °C)). The exhaust speed was adjusted so that the pressure inside the device was 0.2 Pa. Thereafter, a 200 W DC pulse current (150 kHz) was applied to the target surface, and while the substrate was rotated in front of the target, CuO was deposited on the surface of the substrate. x A film was formed.

[0117] Then, the obtained CuO x The film was baked at 400°C for 1 hour in an air atmosphere to obtain a far-infrared transmitting member.

[0118] (Example 3) In Example 3, a functional film was formed on each side of the substrate by magnetron sputtering to produce a far-infrared transmitting member. In Example 3, the substrate was the same Si as in Example 1, and the functional film was a NiO x In Example 3, the thickness of the substrate was the same as in Example 1, and the thickness of the functional film was 1.14 μm.

[0119] In Example 3, first, NiO, a film-forming material, was placed in a magnetron sputtering device. x The target and the substrate were placed facing each other. Next, the entire inside of the apparatus was evacuated to a vacuum. Then, the pressure inside the apparatus was reduced to 5×10 -4 When the pressure reached 0.5 Pa, a total of 80 SCCM of Ar gas and oxygen gas was flowed. The exhaust speed was adjusted so that the pressure inside the device was 0.5 Pa. After that, while the substrate temperature was heated to 150°C, a 400 W DC pulse current (20 kHz) was applied to the target surface, and NiO was deposited on the surface of the substrate. x A film was formed.

[0120] (Example 4) In Example 4, a black ceramic film is formed on the surface of the substrate facing the exterior of the vehicle, and a NiO x In Example 4, the black ceramic was formed using a black paste (Black ink N9-104, manufactured by Ferro Corporation) and a screen printer. In Example 4, the thickness of the black ceramic film was 10 μm, and NiO x In Example 4, a far-infrared transmitting member was produced in the same manner as in Example 3 except for the above.

[0121] (Example 5) In Example 5, a ZrO2 film was formed on each of both sides of the substrate by magnetron sputtering to form a far-infrared transmitting member. In Example 5, the ZrO2 film was formed by sputtering using a Zr target. In Example 5, the thickness of the ZrO2 film was set to 1.3 μm. In Example 5, the far-infrared transmitting member was manufactured by the same method as in Example 4 except for this.

[0122] (Example 6) In Example 6, functional films were formed on both sides of the substrate by magnetron sputtering to form a far-infrared transmitting component. In Example 6, from the substrate side, a Ge film as a high refractive index layer and a NiO film as a visible light absorbing layer were formed. xIn Example 6, the Ge film was formed by sputtering using a Ge target. In Example 6, the Ge film was formed to a thickness of 1.15 μm, and the NiO x In Example 6, a far-infrared transmitting member was produced in the same manner as in Example 5 except for the thickness of the film, which was 1.14 μm.

[0123] (Example 7) In Example 7, functional films were formed on both sides of the substrate by magnetron sputtering to form a far-infrared transmitting component. In Example 7, a Ge film was formed as a high refractive index layer, an MgO film as a low refractive index layer, and a NiO film as a visible light absorbing layer, in that order from the substrate side. x In Example 7, the MgO film was formed by sputtering using a Mg target. In Example 7, the Ge film had a thickness of 1.2 μm, the MgO film had a thickness of 0.3 μm, and the NiO x In Example 7, a far-infrared transmitting member was produced in the same manner as in Example 6 except for the thickness of the film, which was 0.9 μm.

[0124] (Example 8) In Example 8, functional films were formed on both sides of the substrate by magnetron sputtering, to produce a far-infrared transmitting component. In Example 8, five layers of low-refractive-index MgO films and high-refractive-index Ge films were alternately stacked in this order from the substrate side, and a visible light absorbing layer of NiO x In Example 8, from the substrate side, the thickness of the MgO film was 0.13 μm, the thickness of the Ge film was 0.34 μm, the thickness of the MgO film was 0.27 μm, the thickness of the Ge film was 1.45 μm, the thickness of the MgO film was 0.23 μm, and the thickness of the NiO film was 1.45 μm. x In Example 8, a far-infrared transmitting member was produced in the same manner as in Example 7 except for the thickness of the film, which was 0.9 μm.

[0125] (Example 9) In Example 9, a functional film and a protective film were formed on both sides of the substrate by magnetron sputtering, respectively, to produce a far-infrared transmitting member. xIn Example 9, the NiO x The thickness of the film was 1 μm, and the thickness of the ZrO 2 film was 0.3 μm. In Example 9, a far-infrared transmitting member was produced in the same manner as in Example 8 except for this.

[0126] (Example 10) In Example 10, a functional film and a protective film were formed on both sides of the substrate by magnetron sputtering, respectively, to produce a far-infrared transmitting member. x In Example 10, the NiO x The thickness of the Al2O3 film was 1.14 μm, and the thickness of the Al2O3 film was 0.08 μm. In Example 10, a far-infrared transmitting member was produced in the same manner as in Example 9 except for these points.

[0127] (Example 11) In Example 11, an adhesive film and a functional film were formed on both sides of the substrate by magnetron sputtering, respectively, to produce a far-infrared transmitting member. In Example 11, the adhesive film was a Si film, and the functional film was a NiO film, which was a visible light absorbing layer. x In Example 11, the thickness of the Si film was 0.1 μm, and the NiO x In Example 11, a far-infrared transmitting member was produced in the same manner as in Example 10 except for the above.

[0128] (Example 12) In Example 12, a diamond-like carbon (DLC) film was formed as a visible light absorbing layer on the surface of the substrate facing the exterior side of the vehicle, and a high-refractive index Ge film and a low-refractive index ZnS film were laminated in this order as functional films on the surface of the substrate facing the interior side of the vehicle to form a far-infrared transmitting member. In Example 12, the thickness of the substrate was the same as in Example 1, the diamond-like carbon (DLC) film was formed by plasma CVD, and the Ge film and ZnS film were formed by vapor deposition. In Example 12, the thickness of the diamond-like carbon film was 1 μm, the thickness of the Ge film was 0.1 μm, and the thickness of the ZnS film was 1.2 μm. In Example 12, the far-infrared transmitting member was manufactured using the same method as in Example 11 except for the above.

[0129] (Example 13) In Example 13, a Ge film and a ZnS film were laminated in this order on both sides of a substrate to form a far-infrared transmitting member. In Example 13, the thickness of the Ge film was set to 0.1 μm, and the thickness of the ZnS film was set to 1.2 μm. In Example 13, the far-infrared transmitting member was manufactured in the same manner as in Example 12 except for this.

[0130] (Example 14) In Example 14, the substrate itself was used as the far-infrared transmitting member. That is, in Example 14, only the substrate was prepared, and no film was formed on the substrate. In Example 14, ZnS (MS grade) was used as the substrate. The thickness of the substrate was 2 mm ± 0.1 mm.

[0131] (Example 15) In Example 15, a functional film was formed on each side of the substrate by magnetron sputtering to produce a far-infrared transmitting member. In Example 15, the same ZnS as in Example 14 was used as the substrate, and a Ge film as a high refractive index layer and a NiO film as a visible light absorbing layer were formed in this order from the substrate side. x In Example 15, the Ge film was formed by sputtering using a Ge target. In Example 15, the Ge film was formed to a thickness of 1.15 μm, and the NiO xIn Example 15, a far-infrared transmitting member was produced in the same manner as in Example 6 except for the thickness of the film, which was 1.14 μm.

[0132] (Example 16) In Example 16, the visible light reflectance and visible light reflectance dispersion values of the best mode configuration of Non-Patent Document 2 were calculated using optical simulation. The substrate was a P-type Si substrate (Matsuzaki Manufacturing Co., Ltd.) with a thickness of 0.525 mm as described in Non-Patent Document 2, and NiO obtained by the method described in Non-Patent Document 2 was used as a functional layer on both sides of the substrate. x The NiO film was placed x The film thickness was set to 1.2 μm, and NiO obtained by the method described in Non-Patent Document 2 x The visible light reflectance and visible light reflectance dispersion were calculated by optical simulation using the optical constants of the film. The optical simulation was performed using simulation software (TFCalc, manufactured by Hulinks Co., Ltd.). The far-infrared average transmittance was cited from Non-Patent Document 2.

[0133] (Example 16) In Example 16, the substrate was a P-type Si substrate (Matsuzaki Manufacturing Co., Ltd.) with a thickness of 0.525 mm as described in Non-Patent Document 2, and NiO obtained by the method described in Non-Patent Document 2 was used as a functional layer on both sides of the substrate. x First, a Ni target, which is the raw material for film formation, and a substrate were placed facing each other in a magnetron sputtering device. Next, the entire device was evacuated to a vacuum. Then, when the pressure inside the device reached 5 × 10E-4 Pa, Ar gas and oxygen gas were flowed at a total rate of 20 SCCM (standard cc / min, 1 atm (25 °C)). The pumping speed was adjusted so that the pressure inside the device at this time was 3.5 mTorr. After that, a 400 W high-frequency current was applied to the target surface, and NiO was deposited on the surface of the substrate. x Then, the obtained NiO x The film was fabricated by annealing it in air at 600°C for 1 hour. x The film thickness was set to 1.2 μm.

[0134] In addition, in Examples 2, 3, 6, 7, 8, 9, 10, 11, 12, and 15, a visible light absorbing layer having an extinction coefficient of 0.04 or more for light with a wavelength of 550 nm is provided, and in Example 16, a NiO x The extinction coefficient of light with a wavelength of 550 nm is 0.02, which is unsuitable for a visible light absorption layer. The extinction coefficient of light with a wavelength of 550 nm was determined by fitting an optical model using polarization information obtained by a spectroscopic ellipsometer and spectral transmittance measured in accordance with JIS R3106.

[0135] (evaluation) The samples of Examples 1 to 15 were evaluated for visible light performance and far-infrared transmission performance. For the visible light performance, the reflectance of the vehicle exterior surface of each sample to visible light and the dispersion of the reflectance to visible light were measured. The reflectance to visible light was measured using the method specified in JIS R3106. The dispersion for each reflectance at 1 nm increments for light with wavelengths of 360 nm to 830 nm, measured using the method specified in JIS R3106, was calculated as the dispersion of the reflectance to visible light. A reflectance to visible light of 15% or less was indicated by a double circle, a circle for more than 15% and less than 20%, a triangle for more than 20% and less than 25%, and a cross for less than 15%. A triangle, circle, or double circle was considered acceptable. A dispersion of 5 or less was indicated by a double circle, a circle for more than 5 and less than 10, a triangle for more than 10 and less than 30, and a cross for 30 or more. A triangle, circle, or double circle was considered acceptable.

[0136] The far-infrared transmission performance was evaluated by evaluating the average transmittance of the sample. The average transmittance here is the average value of the transmittance of light at each wavelength from 8 μm to 12 μm. In this example, the transmittance of light at each wavelength from 8 μm to 12 μm was measured using a Fourier transform infrared spectrometer (manufactured by ThermoScientific, product name: Nicolet iS10), and the average transmittance was calculated from the measured transmittance. In evaluating the far-infrared transmission performance, an average transmittance of 70% or more was marked with a double circle, a value of 65% or more but less than 70% was marked with a circle, a value of 50% or more but less than 65% was marked with a triangle, and a value of less than 50% was marked with an X. A triangle, circle, or double circle was considered to be pass.

[0137] (Evaluation of Example 16) In Example 16, the values of visible light reflectance and visible light reflectance dispersion of the best mode configuration of Non-Patent Document 2 were calculated using optical simulation. x The visible light reflectance and visible light reflectance dispersion were calculated by optical simulation using the optical constants of the film. The optical simulation was performed using simulation software (TFCalc, manufactured by Hulinks Co., Ltd.). The far-infrared average transmittance was cited from Non-Patent Document 2.

[0138] (Evaluation results) The evaluation results of each sample are shown in Tables 1 to 3. As shown in Tables 1 to 3, it can be seen that all of the visible light reflectance, dispersion, and average far-infrared transmittance are satisfied in Examples 2, 3, 6, 7, 8, 9, 10, 11, 12, and 15, which are working examples. On the other hand, it can be seen that at least one of the visible light reflectance, dispersion, and average far-infrared transmittance is not satisfied in Comparative Examples 1, 4, 5, 13, and 14.

[0139] 8 and 9 are graphs showing the evaluation results of each example. FIG. 8 is a graph showing the reflectance for each wavelength in the visible light wavelength band for Examples 5 and 13. Line segment L5 in FIG. 8 shows the results for Example 5, and line segment L13 shows the results for Example 13. As shown in FIG. 8, it can be seen that the difference in reflectance for each wavelength (i.e., dispersion) is large in Examples 5 and 13. When the difference in reflectance for each wavelength (i.e., dispersion) is large, rainbow-colored optical interference colors resulting from the difference in intensity of reflected light for each wavelength occur within the plane of the infrared-transmitting substrate and become noticeable.

[0140] FIG. 9 is a graph showing the reflectance for each wavelength in the visible light wavelength band for Examples 1, 3, 4, 8, 10, 12, and 15. Line L1 in FIG. 8 represents the results for Example 1, line L3 represents the results for Example 3, line L4 represents the results for Example 4, line L8 represents the results for Example 8, line L10 represents the results for Example 10, line L12 represents the results for Example 12, and line L15 represents the results for Example 15. As shown in FIG. 9, it can be seen that the difference in reflectance for each wavelength (i.e., dispersion) shown in FIG. 9 is small in Examples 1, 3, 4, 8, 12, and 15. When the difference in reflectance for each wavelength (i.e., dispersion) is 30 or less, rainbow-colored optical interference colors are not generated within the plane of the infrared-transmitting substrate, and a blackish appearance that is highly compatible with the light-blocking region is obtained. In Example 1, in addition to large dispersion for visible light, the visible light reflectance is high at over 25%, resulting in a glaring appearance that stands out. In Example 4, the dispersion for visible light is very small and the visible light reflectance is sufficiently low, but the far-infrared transmission performance is poor. In Examples 3, 8, 12, and 15, both the reflectance dispersion and visible light reflectance are sufficiently small, resulting in a blackish, inconspicuous appearance without glare.

[0141] Although the embodiments of the present invention have been described above, the embodiments are not limited to the contents of these embodiments. Furthermore, the above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the scope of what is called equivalents. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the above-described embodiments. [Explanation of symbols]

[0142] 1. Vehicle glass 10, 12, 14 Glass substrate 16 Middle class 18 Light blocking layer 20 Far-infrared transmitting material 30 Base material 31 Functional membrane 32 Visible light absorption layer

Claims

1. A glass substrate having an opening formed therethrough from one surface to the other surface in the thickness direction; a far-infrared-transmitting member disposed in the opening and including a substrate that transmits far-infrared rays and a functional film formed on the substrate; and The far-infrared transmitting member has a dispersion of reflectance in 1 nm increments for light with wavelengths of 360 nm to 830 nm of 30 or less, a reflectance of visible light specified in JIS R3106 of 25% or less, and an average transmittance of light with wavelengths of 8 μm to 12 μm of 50% or more. Vehicle glass.

2. 2. The vehicle glass according to claim 1, wherein the average transmittance of light having a wavelength of 8 μm to 12 μm is 65% or more.

3. 3. The vehicle glass according to claim 1, wherein the functional film has one or more visible light absorbing layers containing a metal oxide as a main component.

4. The visible light absorbing layer is made of NiO ｘ The vehicle glass according to claim 3, which is mainly composed of

5. The visible light absorbing layer is made of CuO ｘ and MnO ｘ 4. The vehicle glass according to claim 3, which is mainly composed of at least one material selected from the group consisting of:

6. 5. The vehicle glass according to claim 4, wherein the visible light absorbing layer has an extinction coefficient of 0.04 or more for light with a wavelength of 550 nm.

7. 4. The vehicle glass according to claim 3, wherein the functional film has at least one high refractive index layer having a refractive index for light having a wavelength of 10 μm higher than that of the visible light absorbing layer.

8. 4. The vehicle glass according to claim 3, wherein the functional film has at least one low refractive index layer having a refractive index for light with a wavelength of 10 μm lower than that of the visible light absorbing layer.

9. the functional film has one or more high-refractive index layers having a refractive index for light with a wavelength of 10 μm higher than that of the visible light absorbing layer, and one or more low-refractive index layers having a refractive index for light with a wavelength of 10 μm lower than that of the visible light absorbing layer; The vehicle glass according to claim 3 , wherein the high refractive index layers and the low refractive index layers are alternately laminated between the substrate and the visible light absorbing layer.

10. The vehicle glass according to claim 7 , wherein the high refractive index layer contains at least one material selected from the group consisting of Si and Ge as a main component.

11. The vehicle glass according to claim 8 , wherein the low refractive index layer contains MgO as a main component.

12. 3. The vehicle glass according to claim 1, further comprising a protective film formed on an outer surface thereof and having a refractive index of 2.5 or less for light having a wavelength of 550 nm.

13. The protective film is made of ZrO ２ , Al ２ O ３ , TiO ２ , Si ３ N ４、 13. The vehicle glass according to claim 12, comprising at least one material selected from the group consisting of AlN and diamond-like carbon.

14. 3. The vehicle glass according to claim 1, wherein the substrate contains at least one material selected from the group consisting of Si, Ge, ZnS, and chalcogenide glass.

15. forming a functional film on a substrate that transmits far-infrared rays, and producing a far-infrared transmitting member having a dispersion of reflectance in 1 nm increments of 30 or less for light with wavelengths of 360 nm to 830 nm, a reflectance of visible light specified in JIS R3106 of 25% or less, and an average transmittance of 50% or more for light with wavelengths of 8 μm to 12 μm; a glass substrate having an opening formed therein, the opening extending from one surface to the other surface in a thickness direction, and the far-infrared transmitting member disposed in the opening, thereby manufacturing a glass for a vehicle; Including, A method for manufacturing vehicle glass.

16. The method for manufacturing a glass for a vehicle according to claim 15, wherein the functional film is formed by sputtering.

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