Transmission member

Abstract

The present invention improves abrasion resistance while allowing the transmission of light in a plurality of wavelength ranges. A transmission member (20) includes a base material (30) which transmits far infrared rays, and a first functional film (32) formed on the base material (30). The average transmittance of light having wavelengths of 8-12 μm is 50% or more, and the transmittance of light from a laser source that emits light having a wavelength in the range of 0.8-1.8 μm is 80% or more. The refractive index of the outermost layer (34) of the first functional film (32) with respect to light from the laser source is 1.7 or more.

Description

Transparent material

[0001] The present invention relates to a transparent member.

[0002] For example, with the increasing diversification of sensors mounted on vehicles, etc., there is a demand for components that can appropriately transmit light in multiple wavelength bands. For example, Patent Document 1 describes a multilayer antireflection coating that has an antireflection effect for both visible light in the wavelength band of 0.4 μm to 0.7 μm and far-infrared light in the wavelength band of 8 μm to 12 μm. Patent Document 1 describes a configuration in which a high refractive index film and a low refractive index film are laminated in this order from the substrate side.

[0003] JP-A-4-73601 JP-A-2009-86533 Correlation between Optical Properties and Hardness of Diamond-Like Carbon Films, M. Hiratsuka et al., JSME, 7, 2 (2013)

[0004] In a member that transmits light in multiple wavelength bands, it is required to improve scratch resistance. However, the multilayer antireflection coating of Patent Document 1 has a low refractive index film as the outermost layer. ZrO, which is known as a high-hardness film, is used. ２ , Si ３ N ４ Although scratch-resistant films such as diamond-like carbon (DLC) have a high refractive index of 1.8 or more, it is known that the film hardness of DLC has a positive correlation with the refractive index of the film (see, for example, Fig. 7 of Non-Patent Document 1), and the transparent member of Patent Document 1, which has a low refractive index film as its outermost layer, is easily scratched. On the other hand, the transparent member of Patent Document 2 has an outermost layer made of a high refractive index film and is excellent in scratch resistance, but cannot transmit light of multiple wavelength bands.

[0005] An object of the present invention is to provide a transmissive member that can transmit light in a plurality of wavelength bands while improving scratch resistance.

[0006] The transparent member according to the present disclosure includes a substrate that transmits far-infrared rays and a functional film formed on the substrate, and has an average transmittance of 50% or more for light with a wavelength of 8 μm to 12 μm, and a transmittance of 80% or more for light from a laser light source that emits light with a wavelength in the range of 0.8 μm to 1.8 μm, and the outermost layer of the functional film has a refractive index of 1.7 or more for light from the laser light source.

[0007] According to the present invention, it is possible to improve scratch resistance while transmitting light in a plurality of wavelength bands.

[0008] FIG. 1 is a schematic diagram showing a state in which a vehicle glass according to this embodiment is mounted on a vehicle. FIG. 2 is a schematic plan view of the vehicle glass according to this embodiment. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2. FIG. 4 is a cross-sectional view taken along line B-B in FIG. 2. FIG. 5 is a schematic cross-sectional view of a transmissive member according to this embodiment. FIG. 6 is a schematic cross-sectional view showing an example of an intermediate layer. FIG. 7 is a schematic cross-sectional view showing an example of an intermediate layer. FIG. 8 is a graph showing simulation results of visible and near-infrared transmission spectra for Examples 2 and 4. FIG. 9 is a graph showing simulation results of visible and near-infrared reflection spectra for Examples 2 and 4. FIG. 10 is a graph showing simulation results of far-infrared transmission spectra for Examples 2 and 4. FIG. 11 is a graph showing simulation results of far-infrared reflection spectra for Examples 2 and 4.

[0009] 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.

[0010] (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.

[0011] The vehicle glass 1, the far-infrared camera CA1, and the visible light camera CA2 constitute the 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, LiDAR or millimeter-wave radar. Here, far-infrared rays refer to, for example, electromagnetic waves with a wavelength of 8 μm to 13 μm, and visible light refers to, for example, electromagnetic waves with a wavelength of 360 nm to 830 nm. 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.

[0012] (Vehicle Glass) FIG. 2 is a schematic plan view of a vehicle glass according to this embodiment. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2. FIG. 4 is a cross-sectional view taken along cross section B-B in FIG. 2. As shown in FIG. 2, hereinafter, the upper edge of the vehicle glass 1 will be referred to as an upper edge portion 1a, the lower edge as a lower edge portion 1b, one side edge as a side edge portion 1c, and the other side edge as a 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 installed in 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 installed in a vehicle V. The side edge portion 1c is an edge portion located on one side when the vehicle glass 1 is installed in a vehicle V. The side edge portion 1d is an edge portion located on the other side when the vehicle glass 1 is installed in a vehicle V.

[0013] 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. However, if the surface of the vehicle glass 1 is curved, for example, the X direction and the Y direction 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.

[0014] 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.

[0015] 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.

[0016] 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 far-infrared transmitting region B and the visible light transmitting region C are surrounded by the light-shielding region A2a. 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 viewpoint of design because the wiring of the various sensors is not visible from outside the vehicle.

[0017] 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 interlayer film 16, and a light-shielding layer 18. The vehicle glass 1 has the glass substrate 12, the interlayer film 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 interlayer film 16.

[0018] The glass substrates 12, 14 may be made of, for example, soda lime glass, borosilicate glass, or aluminosilicate glass. The interlayer film 16 is an adhesive layer that bonds the glass substrates 12, 14 together. The interlayer film 16 may be made of, for example, a modified polyvinyl butyral (hereinafter also referred to as PVB) material, an ethylene-vinyl acetate copolymer (EVA)-based material, a urethane resin material, or a polyvinyl 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 interlayer film 16 and fixed (adhered) to the interlayer film 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 interlayer film 16 and fixed (adhered) to the interlayer film 16. As described above, 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 interlayer film 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.

[0019] 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.

[0020] 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.

[0021] (Light-shielding region) 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 interlayer 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 interlayer 16, and the glass base 14 are laminated, and the light-shielding layer 18 is not laminated.

[0022] (Far-infrared ray transmitting region) 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 transparent member 20 is provided within the opening 19. The region where the opening 19 is formed and the transparent member 20 is provided is the far-infrared ray transmitting region B. That is, the far-infrared ray transmitting region B is a region where the opening 19 and the transparent member 20 disposed within the opening 19 are provided. Because the light-shielding layer 18 does not transmit far-infrared rays, the light-shielding layer 18 is not provided in the far-infrared ray transmitting region B. That is, the glass base 12, the interlayer 16, the glass base 14, and the light-shielding layer 18 are not provided in the far-infrared ray transmitting region B, and the transparent member 20 is provided in the formed opening 19. The transparent member 20 will be described later.

[0023] 4, the visible light transmitting region C, like the light-transmitting region A1, is a region in the Z direction where the glass base 10 does not include the light-shielding layer 18. In other words, the visible light transmitting region C is a region where the glass base 12, the interlayer film 16, and the glass base 14 are laminated, but where the light-shielding layer 18 is not laminated.

[0024] As shown in FIG. 2 , the visible light transmission region C is preferably located near the far-infrared transmission region B. Specifically, the center of the far-infrared transmission region B as viewed from the Z direction is defined as center point OB, and the center of the visible light transmission region C as viewed from the Z direction is defined as center point OC. If the shortest distance between the far-infrared transmission region B (opening 19) and the visible light transmission region C as viewed from the Z direction is defined as distance L, distance L is preferably greater than 0 mm and less than 100 mm, and more preferably greater than 10 mm and less than 80 mm. Positioning the visible light transmission region C within this range relative to the far-infrared transmission 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 transmission 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.

[0025] 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 ensured.

[0026] (Transmitting Member) The transmitting member 20 provided in the far-infrared transmitting region B will now be described in detail. FIG. 5 is a schematic cross-sectional view of the transmitting member according to this embodiment. As shown in FIG. 5, the transmitting member 20 includes a substrate 30, a first functional film 32 as a functional film formed on the substrate 30, and a second functional film 40 formed on the substrate 30. In this embodiment, the first functional film 32 is formed on one surface 30a of the substrate 30. The surface 30a faces the exterior side of the vehicle when the transmitting member 20 is mounted on the vehicle glass 1. The second functional film 40 is formed on the other surface 30b of the substrate 30. The surface 30b faces the interior side of the vehicle when the transmitting member 20 is mounted on the vehicle glass 1. However, the second functional film 40 is not an essential component, and no layer other than the substrate 30 may be provided on the surface 30b.

[0027] In this embodiment, the transparent member 20 is provided in the light-shielding area A2 of the vehicle glass 1, which is a window member of the vehicle V. However, this is not limited thereto, and the transparent member 20 may be provided in any exterior member of the vehicle V, such as an exterior member for a pillar of the vehicle V. Furthermore, a sensor for detecting light in a wavelength range of 0.8 μm to 1.8 μm may be provided on the vehicle glass 1 on the interior side of the vehicle V, and an opening may be formed in the vehicle glass 1 at a position facing the sensor, with the transparent member 20 provided in the opening. Hereinafter, light in the wavelength range of 0.8 μm to 1.8 μm will be referred to as near-infrared light, as appropriate. Examples of sensors that detect near-infrared light in the wavelength range of 0.8 μm to 1.8 μm include LiDAR using near-infrared light. Furthermore, an opening may be formed in the vehicle glass 1 at a position facing the visible light camera CA2, and the transparent member 20 may be provided in the opening. That is, the transparent member 20 may be provided in at least one of an opening provided in the vehicle glass 1 at a position facing a sensor (far-infrared camera CA1) that detects light with a wavelength in the range of 8 μm to 12 μm, an opening provided in a position facing a sensor that detects light with a wavelength of 0.8 μm to 1.8 μm, and an opening provided in a position facing a sensor that detects light with a wavelength of 360 nm to 830 nm (visible light camera CA2). Furthermore, the transparent member 20 is not limited to being provided in the vehicle V, and may be used for any purpose.

[0028] In the following description, light from a laser light source emitting light in the wavelength range of 0.8 μm to 1.8 μm will be referred to as single-wavelength light where appropriate. Single-wavelength light can be said to be light of a predetermined wavelength (single wavelength) within the wavelength range of 0.8 μm to 1.8 μm. Examples of wavelengths of single-wavelength light include 0.905 μm (905 nm), 1.35 μm (1350 nm), and 1.55 μm (1550 nm).

[0029] (Substrate) The substrate 30 is preferably a material capable of transmitting far-infrared rays. The substrate 30 preferably has an internal transmittance of 50% or more for light with a wavelength of 10 μm (far-infrared rays), more preferably 60% or more, and even more preferably 70% or more. Furthermore, the substrate 30 preferably has an average internal transmittance of 50% or more for light with a wavelength of 8 μm to 12 μm, more preferably 60% or more, and even more preferably 70% or more. When the internal transmittance at 10 μm and the average internal transmittance at 8 μm to 12 μm of the substrate 30 are within these numerical ranges, far-infrared rays are appropriately transmitted, enabling the performance of, for example, the far-infrared camera CA1 to be fully demonstrated. Note that the average internal transmittance here refers to the average value of the internal transmittance for light of each wavelength in that wavelength band (here, 8 μm to 12 μm). The internal transmittance can be appropriately adjusted by adjusting the material and thickness of the substrate 30.

[0030] The substrate 30 is preferably a material that can transmit near-infrared rays. The substrate 30 preferably has an internal transmittance of 80% or more for single-wavelength light, more preferably 90% or more, and even more preferably 95% or more. The internal transmittance can be appropriately adjusted by adjusting the material and thickness of the substrate 30.

[0031] The internal transmittance of the substrate 30 is the transmittance excluding the surface reflection loss on the incident side and the exit side, and is well known in the art, and may be measured by a commonly used method. The measurement is performed, for example, as follows.

[0032] A pair of flat samples (a first sample and a second sample) are prepared, each made of a substrate of the same composition but with a different thickness. Both surfaces of the flat samples are parallel to each other and optically polished. The external transmittance including surface reflection loss of the first sample is T1, the external transmittance including surface reflection loss of the second sample is T2, the thickness of the first sample is Td1 (mm), and the thickness of the second sample is Td2 (mm), where Td1 < Td2. The internal transmittance τ at a thickness Tdx (mm) can be calculated using the following formula (1):

[0033] τ = exp[-Tdx×(lnT1-lnT2) / ΔTd] ...(1)

[0034] The external transmittance of infrared light can be measured, for example, by a Fourier transform infrared spectrometer (manufactured by ThermoScientific, trade name: Nicolet iS10).

[0035] 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 this range 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.

[0036] The refractive index of the substrate 30 with respect to single wavelength light is preferably 1.8 to 4.2, more preferably 2.0 to 3.6, and even more preferably 2.1 to 3.6. When the refractive index of the substrate 30 is in this range, the substrate 30 can adequately transmit single wavelength light and fully exhibit the performance of a sensor that detects, for example, near-infrared rays.

[0037] The thickness D1 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 D1 is within this range, the substrate 30 can adequately transmit far-infrared rays and single-wavelength light while maintaining strength. The thickness D1 can also be considered as the length in the Z direction from the surface 30a to the surface 30b of the substrate 30.

[0038] 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 and single-wavelength light can be appropriately transmitted. A preferred composition of chalcogenide glass is, in atomic %, Ge+Ga: 7% to 25%, Sb: 0% to 35%, Bi: 0% to 20%, Zn: 0% to 20%, Sn: 0% to 20%, Si: 0% to 20%, La: 0% to 20%, S+Se+Te: 55% to 80%, Ti: 0.005% to 0.3%, Li+Na+K+Cs: 0% to 20%, and F+Cl+Br+I: 0% to 20%. This glass preferably has a glass transition temperature (Tg) of 140°C to 550°C.

[0039] It is more preferable to use Si or ZnS as the material for the substrate 30 .

[0040] (First Functional Film) The first functional film 32 is formed on the vehicle exterior surface 30a of the substrate 30. The first functional film 32 is an anti-reflection film against far-infrared rays and single-wavelength light. The first functional film 32 includes an outermost layer 34, a contact layer 36, and an intermediate layer 38. The outermost layer 34 is the layer of the first functional film 32 that is located farthest from the substrate 30, i.e., in this embodiment, on the outermost side of the vehicle. In other words, the outermost layer 34 is the outermost layer of the transparent member 20 (in this embodiment, on the outermost side of the vehicle) and is exposed to the outside. The contact layer 36 is a layer of the first functional film 32 that is located closer to the substrate 30 than the outermost layer 34 (in this embodiment, closer to the vehicle interior than the outermost layer 34) and is in contact with the outermost layer 34 on the substrate 30 side of the outermost layer 34. That is, the contact layer 36 is a layer of the first functional membrane 32 that is provided at a position second farthest from the substrate 30 (in this embodiment, the second position counting from the vehicle exterior). The intermediate layer 38 is a layer of the first functional membrane 32 that is provided closer to the substrate 30 than the outermost layer 34 (in this embodiment, closer to the vehicle interior than the outermost layer 34). That is, the intermediate layer 38 is provided between the substrate 30 and the outermost layer 34. Furthermore, in this embodiment, the intermediate layer 38 is provided closer to the substrate 30 than the contact layer 36 in the first functional membrane 32, and can be said to be provided between the substrate 30 and the contact layer 36. However, the first functional membrane 32 does not have to include at least one of the contact layer 36 and the intermediate layer 38. That is, the first functional film 32 may include only the outermost layer 34, only the outermost layer 34 and the contact layer 36, or only the outermost layer 34 and the intermediate layer 38, out of the outermost layer 34, the contact layer 36, and the intermediate layer 38.

[0041] The average refractive index of the first functional film 32 for light with a wavelength of 10 μm is preferably close to the square root of the refractive index of the substrate 30 for light with a wavelength of 10 μm, more preferably 1.3 to 2.5, even more preferably 1.4 to 2.2, particularly preferably 1.45 to 2.00, and most preferably 1.53 to 1.90. Having the average refractive index of the first functional film 32 within this range allows for appropriate transmission of far-infrared rays. The average refractive index of the first functional film 32 can be calculated by {the sum of the optical thicknesses (= physical thickness × refractive index) of the layers constituting the first functional film 32} / {the total thickness (physical thickness) of each layer}.

[0042] (Outermost Layer) The refractive index of the outermost layer 34 with respect to single-wavelength light is 1.7 or more, preferably 1.7 to 4.2, more preferably 1.8 to 3.6, even more preferably 1.9 to 2.5, even more preferably 2.0 to 2.4, and particularly preferably 2.0 to less than 2.4. Having the refractive index of the outermost layer 34 within this range allows for appropriate transmission of single-wavelength light while improving the film density of the outermost layer 34 and appropriately improving scratch resistance. In this embodiment, the wavelength of the single-wavelength light is 905 nm, 1350 nm, or 1550 nm, so it is preferable that the refractive index of the outermost layer 34 with respect to at least one of 905 nm, 1350 nm, and 1550 nm be within the above range. Other characteristics with respect to single-wavelength light hereinafter may also refer to characteristics with respect to at least one of 905 nm, 1350 nm, and 1550 nm.

[0043] The outermost layer 34 is preferably capable of transmitting far-infrared rays. The outermost layer 34 preferably has an extinction coefficient for light with a wavelength of 10 μm of 0.10 or less, more preferably 0.05 or less, and even more preferably 0.04 or less. The extinction coefficient can be determined by fitting an optical model using, for example, polarization information obtained by an infrared spectroscopic ellipsometer (IR-VASE-UT, manufactured by J.A. Woollam Co.) and a spectral transmission spectrum obtained by a Fourier transform infrared spectrometer.

[0044] The outermost layer 34 is preferably capable of transmitting single wavelength light. The outermost layer 34 preferably has an extinction coefficient for single wavelength light of 0.10 or less, more preferably 0.05 or less, and even more preferably 0.04 or less.

[0045] The thickness D2 of the outermost layer 34 is preferably 20 nm or more, more preferably 30 nm or more and 500 nm or less, even more preferably 50 nm or more and 400 nm or less, and most preferably 100 nm or more and 350 nm or less. The thickness D2 can also be considered the length in the Z direction from the surface of the outermost layer 34 on the Z direction side to the surface opposite the Z direction. The ratio of the thickness D2 of the outermost layer 34 to the thickness D1 of the substrate 30 is preferably 0.0005% or more and 0.030% or less, more preferably 0.001% or more and 0.020% or less, and even more preferably 0.002% or more and 0.02% or less. The ratio of the thickness D2 of the outermost layer 34 to the thickness D4 of the first functional film 32 is preferably 1% or more and 30% or less, more preferably 3% or more and 25% or less, and most preferably 5% or more and 25% or less. The thickness D4 of the first functional film 32 can also be considered as the length in the Z direction from the surface on the Z direction side of the first functional film 32 to the surface opposite the Z direction. When the thickness D2 is in this range, it is possible to appropriately transmit far infrared rays and single-wavelength light and appropriately improve scratch resistance.

[0046] The surface of the outermost layer 34 opposite the substrate 30 is referred to as the surface 34a. The surface 34a is the surface exposed to the outside, and in this embodiment, it can be said to be the surface facing the vehicle exterior. In this case, the arithmetic mean roughness Ra (surface roughness) of the surface 34a of the outermost layer 34 is preferably 7.0 nm or less, more preferably 5.0 nm or less, even more preferably 4.0 nm or less, and most preferably 3.0 nm or less. By having the arithmetic mean roughness Ra of the surface 34a within this range, the dynamic friction coefficient and the change in surface roughness before and after abrasion can be reduced, and the abrasion resistance can be more appropriately improved. Note that the arithmetic mean roughness Ra refers to the arithmetic mean roughness Ra specified in JIS B 0601:2001.

[0047] The outermost layer 34 may be made of any material, for example, ZrO ２ or TiO ２ , NiO, Si ３ N ４ or DLC is preferably used as the main component, and ZrO ２ It is more preferable that the main component is the above-mentioned compound. Here, the main component may refer to a content of 50% by mass or more relative to the entire outermost layer 34. The content of the main component in the outermost layer 34 is 50% by mass or more and 100% by mass or less, preferably 70% by mass or more and 100% by mass or less, and more preferably 90% by mass or more and 100% by mass or less relative to the entire outermost layer 34. Furthermore, it is preferable that the content of the main component in the outermost layer 34 is 100% by mass, i.e., excluding unavoidable impurities. When the content of the main component in the outermost layer 34 is within this range, it is possible to appropriately transmit far infrared rays and single-wavelength light and improve scratch resistance.

[0048] The outermost layer 34 may contain a secondary component other than the main component. The secondary component is preferably an oxide that transmits far infrared rays and single wavelength light, such as NiO, Y ２ O ３ , HfO ２ , TiO ２ , ZnO, MgO, and Al ２ O ３ At least one of the following can be mentioned.

[0049] (Contact Layer) The refractive index of the contact layer 36 for single-wavelength light is preferably lower than the refractive index of the outermost layer 34 for single-wavelength light. Furthermore, the refractive index of the contact layer 36 for single-wavelength light is preferably equal to or less than the square root of the refractive index of the substrate 30 for single-wavelength light. In other words, the outermost layer 34 functions as a high-refractive index film, and the contact layer 36 functions as a low-refractive index film. The ratio of the refractive index of the contact layer 36 for single-wavelength light to the refractive index of the outermost layer 34 for single-wavelength light is preferably equal to or less than 1, more preferably 0.5 to 1, and even more preferably 0.6 to 0.8. The refractive index of the contact layer 36 for single-wavelength light is preferably 1.7 or less, more preferably 1.0 to 1.5, and even more preferably 1.1 to 1.4. Having the refractive index of the contact layer 36 within this range allows for appropriate transmission of single-wavelength light.

[0050] The contact layer 36 is preferably capable of transmitting far infrared rays. The contact layer 36 preferably has an extinction coefficient for light with a wavelength of 10 μm of 0.10 or less, more preferably 0.05 or less, and even more preferably 0.04 or less.

[0051] The contact layer 36 is preferably capable of transmitting single-wavelength light. The contact layer 36 preferably has an extinction coefficient for single-wavelength light of 0.10 or less, more preferably 0.05 or less, and even more preferably 0.04 or less.

[0052] The thickness D3 of the contact layer 36 is preferably 50 nm or more and 500 nm or less, more preferably 60 nm or more and 400 nm or less, and even more preferably 70 nm or more and 300 nm or less. The thickness D3 can also be considered as the length in the Z direction from the surface of the contact layer 36 on the Z direction side to the surface opposite the Z direction. The ratio of the thickness D3 of the contact layer 36 to the thickness D2 of the outermost layer 34 is preferably 0.5 to 10, more preferably 1 to 6, and even more preferably 1.2 to 3. Having the thickness D2 within this range allows for appropriate transmission of far-infrared rays and single-wavelength light.

[0053] The contact layer 36 may be made of any material, for example, MgF ２ , Y.F. ３ or YbF ３ is preferably the main component, and MgF ２ It is more preferable that the contact layer 36 contains the main component. The content of the main component in the contact layer 36 is 50% by mass or more and 100% by mass or less, preferably 70% by mass or more and 100% by mass or less, and more preferably 90% by mass or more and 100% by mass or less, based on the entire contact layer 36. Furthermore, it is preferable that the content of the main component alone, i.e., the main component excluding unavoidable impurities, is 100% by mass. When the content of the main component in the contact layer 36 is within this range, it can adequately transmit far infrared rays and single-wavelength light.

[0054] (Outermost Layer and Contact Layer) Conventionally, to provide sufficient anti-reflection function against single-wavelength light, it was necessary to stack a high-refractive index layer and a low-refractive index layer in this order on the outermost side. However, because the outermost layer was a low-refractive index layer, scratch resistance could not be improved. In response to this, the present inventors conducted extensive research and devised a way to broaden the refractive index range of the outermost layer 34 that is acceptable for providing sufficient anti-reflection function by relatively increasing the refractive index of the substrate 30 within the above-mentioned range. Specifically, they found that sufficient anti-reflection function against single-wavelength light can be provided even when a low-refractive index layer and a high-refractive index layer are stacked in this order on the outermost side and the outermost layer 34 is a high-refractive index layer. That is, the transparent member 20 according to this embodiment appropriately transmits single-wavelength light by stacking a low-refractive index layer and a high-refractive index layer in this order on the outermost side and making the outermost layer 34 a high-refractive index layer, while improving scratch resistance by making the outermost layer 34 a dense high-refractive index layer.

[0055] The thickness of each film of a two-layer antireflection coating made up of two transparent films having any refractive index can be calculated using equations (2) and (3).

[0056]

[0057] In formulas (2) and (3), n ０ is the refractive index of the medium, n ｓ is the refractive index of the substrate, n１ is the refractive index of the outer film, n ２ is the refractive index of the inner film, δ １ is the outer phase thickness, δ ２ is the inner phase film thickness. The inventors have arranged a high refractive index film on the outside, that is, n １ >n ２ When ３ <n １ ２ And n ２ ２ <n ３ It was found that this would result in an anti-reflection effect.

[0058] (Intermediate Layer) FIGS. 6 and 7 are schematic cross-sectional views showing an example of an intermediate layer. The intermediate layer 38 is capable of transmitting far-infrared light and single-wavelength light. As shown in FIG. 6 , the intermediate layer 38 has a high-refractive index layer 38A and a low-refractive index layer 38B. In the intermediate layer 38, the high-refractive index layer 38A and the low-refractive index layer 38B are alternately stacked. In the example of FIG. 6 , the intermediate layer 38 is stacked on the substrate 30 in the order of the high-refractive index layer 38A and the low-refractive index layer 38B, moving away from the substrate 30. That is, in the intermediate layer 38, the layer formed closest to the substrate 30 is the high-refractive index layer 38A, and the layer farthest from the substrate 30 is the low-refractive index layer 38B.

[0059] However, the layer structure of the intermediate layer 38 is not limited to that shown in Fig. 6, and may be formed by layering the low refractive index layer 38B and the high refractive index layer 38A in this order in the direction away from the substrate 30, as shown in Fig. 7. That is, in the intermediate layer 38, the layer formed closest to the substrate 30 may be the low refractive index layer 38B, and the layer farthest from the substrate 30 may be the high refractive index layer 38A.

[0060] 6 and 7 , the intermediate layer 38 is configured with one high-refractive index layer 38A and one low-refractive index layer 38B stacked together. However, the number of stacked high-refractive index layers 38A and low-refractive index layers 38B is not limited to one, and may be multiple. That is, if a pair of contacting high-refractive index layers 38A and low-refractive index layers 38B is considered a laminate, the number of laminated layers may be arbitrary. The total optical thickness of each layer constituting the first functional film 32 is preferably λ / 4 (λ = 10 μm), more preferably 2 μm or more and 3 μm or less. By selecting the number of stacked layers so that the total optical thickness of each layer of the first functional film 32 falls within this range, far-infrared rays can be transmitted appropriately.

[0061] The intermediate layer 38 is not limited to a configuration in which the high refractive index layer 38A and the low refractive index layer 38B are stacked, but may also have, for example, at least one low refractive index layer 38B. That is, the intermediate layer 38 may be a single-layer film made of one low refractive index layer 38B, but is preferably a multilayer film in which the high refractive index layer 38A and the low refractive index layer 38B are stacked.

[0062] (High Refractive Index Layer) The refractive index of the high refractive index layer 38A with respect to single wavelength light is preferably 1.5 or more, more preferably 1.5 to 4.2, even more preferably 1.6 to 3.6, and most preferably 1.7 to 2.5. When the refractive index of the high refractive index layer 38A is in this range, the single wavelength light can be appropriately transmitted.

[0063] The high refractive index layer 38A is preferably capable of transmitting far infrared rays. The high refractive index layer 38A has an extinction coefficient for light with a wavelength of 10 μm of preferably 0.10 or less, more preferably 0.05 or less, and even more preferably 0.04 or less.

[0064] The high-refractive index layer 38A is preferably capable of transmitting single-wavelength light. The high-refractive index layer 38A has an extinction coefficient for single-wavelength light of preferably 0.10 or less, more preferably 0.05 or less, and even more preferably 0.04 or less.

[0065] The thickness D5 of the high-refractive-index layer 38A is preferably 50 nm or more and 400 nm or less, more preferably 70 nm or more and 300 nm or less, and even more preferably 70 nm or more and 250 nm or less. The thickness D5 can also be considered as the length in the Z direction from the surface of the high-refractive-index layer 38A on the Z-direction side to the surface on the opposite side of the Z-direction. In addition, in a configuration in which the high-refractive-index layer 38A and the low-refractive-index layer 38B are laminated in this order as shown in FIG. 6 , the ratio of the thickness D5 of the high-refractive-index layer 38A to the thickness D6 of the low-refractive-index layer 38B is preferably 10% or more and 150% or less, more preferably 10% or more and 100% or less, and even more preferably 20% or more and 70% or less. 7, in the case where the low refractive index layer 38B and the high refractive index layer 38A are laminated in this order, the ratio of the thickness D5 of the high refractive index layer 38A to the thickness D6 of the low refractive index layer 38B is preferably 5% to 100%, more preferably 10% to 70%, and even more preferably 15% to 50%. When the thickness D5 is in this range, far infrared rays and single-wavelength light can be appropriately transmitted.

[0066] The high refractive index layer 38A may be made of any material, for example, Ge, Si, ZnS, Y ２ O ３ , HfO ２ , TiO ２ , ZnO, MgO, Al ２ O ３ , Si ３ N ４ Preferably, the high-refractive-index layer 38A has a main component 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 more preferably 90% by mass or more and 100% by mass or less, based on the entire high-refractive-index layer 38A. Furthermore, the high-refractive-index layer 38A preferably contains the main component alone, i.e., the main component content excluding unavoidable impurities, is 100% by mass. By having the main component content within this range, the high-refractive-index layer 38A can adequately transmit far-infrared rays and single-wavelength light.

[0067] The high refractive index layer 38A may contain a secondary component other than the main component. The secondary component is preferably an oxide that transmits far infrared rays and single wavelength light, such as NiO, Y ２ O ３ , HfO ２ , TiO ２ , ZnO, MgO, and Al ２ O ３ At least one of the following can be mentioned.

[0068] (Low Refractive Index Layer) The refractive index of the low refractive index layer 38B for single-wavelength light is lower than the refractive index of the high refractive index layer 38A for single-wavelength light. The ratio of the refractive index of the low refractive index layer 38B for single-wavelength light to the refractive index of the high refractive index layer 38A for single-wavelength light is preferably 30% or more and 100% or less, more preferably 50% or more and 90% or less, and even more preferably 60% or more and 80% or less. The refractive index of the low refractive index layer 38B for single-wavelength light is preferably 1.3 or more, more preferably 1.3 or more and 1.6 or less, even more preferably 1.3 or more and 1.5 or less, and most preferably 1.3 or more and 1.45 or less. When the refractive index of the low refractive index layer 38B is within this numerical range, it can appropriately transmit single-wavelength light.

[0069] The low refractive index layer 38B is preferably capable of transmitting far infrared rays. The low refractive index layer 38B has an extinction coefficient for light with a wavelength of 10 μm of preferably 0.10 or less, more preferably 0.05 or less, and even more preferably 0.04 or less.

[0070] The low refractive index layer 38B is preferably capable of transmitting single wavelength light. The low refractive index layer 38B has an extinction coefficient for single wavelength light of preferably 0.10 or less, more preferably 0.05 or less, and even more preferably 0.04 or less.

[0071] The thickness D6 of the low refractive index layer 38B is preferably 50 nm or more and 500 nm or less, more preferably 80 nm or more and 450 nm or less, and even more preferably 100 nm or more and 400 nm or less. The thickness D6 can also be considered as the length in the Z direction from the surface of the low refractive index layer 38B on the Z direction side to the surface opposite the Z direction. When the thickness D6 is in this range, far infrared rays can be appropriately transmitted.

[0072] The low refractive index layer 38B may be made of any material, for example, MgF ２ , Y.F. ３ , or YbF ３ is preferably the main component, and MgF ２ It is more preferable that the low refractive index layer 38B has a content of the main component of 50% by mass or more and 100% by mass or less, preferably 70% by mass or more and 100% by mass or less, and more preferably 90% by mass or more and 100% by mass or less, based on the entire low refractive index layer 38B. Furthermore, it is preferable that the low refractive index layer 38B contains the main component alone, i.e., the content of the main component excluding unavoidable impurities, is 100% by mass. When the content of the main component is within this range, the low refractive index layer 38B can appropriately transmit far infrared rays and single-wavelength light.

[0073] The low refractive index layer 38B may contain a secondary component other than the main component, which is preferably an oxide that transmits far infrared rays and single wavelength light, such as MgO.

[0074] (Second Functional Film) The second functional film 40 provided on the interior surface 30b of the base material 30 is a layer that transmits far infrared rays and single-wavelength light. The second functional film 40 may have the same configuration as the intermediate layer 38.

[0075] (Adhesion Layer) An adhesion layer (not shown) may be formed between the intermediate layer 38 and the substrate 30. The adhesion film is a film that adheres the substrate 30 and the intermediate layer 38 together, in other words, a film that improves the adhesive strength between the substrate 30 and the intermediate layer 38.

[0076] The refractive index of the adhesive layer with respect to single wavelength light is preferably 1.4 or more, more preferably 1.4 to 3.6, and even more preferably 2.0 to 2.4. The refractive index of the adhesive layer with respect to light with a wavelength of 10 μm is preferably 1.4 or more, more preferably 1.4 to 3.6, and even more preferably 1.6 to 2.2. When the refractive index of the adhesive layer is in this numerical range, far infrared rays and single wavelength light can be appropriately transmitted.

[0077] The adhesive layer is preferably capable of transmitting far-infrared rays. The adhesive layer preferably has an extinction coefficient of 0.10 or less, more preferably 0.05 or less, and even more preferably 0.04 or less, with respect to light having a wavelength of 10 μm. The adhesive layer is preferably capable of transmitting single-wavelength light. The adhesive layer is preferably capable of transmitting single-wavelength light. The adhesive layer is preferably capable of transmitting single-wavelength light. The extinction coefficient of 0.10 or less, more preferably 0.05 or less, and even more preferably 0.04 or less.

[0078] The thickness of the adhesion film 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 of the adhesion film within this range allows for appropriate adhesion between the substrate 30 and the intermediate layer 38 while appropriately suppressing reflection of single-wavelength light and far-infrared rays. The thickness of the adhesion film can also be considered as the length in the Z direction from the surface of the adhesion film on the Z direction side to the surface opposite the Z direction. The thickness of the adhesion film is preferably thinner than the thicknesses of the intermediate layer 38, the contact layer 36, and the outermost layer 34. Having the thickness of the adhesion film thinner than these layers reduces the impact on optical performance.

[0079] The material of the adhesive film is arbitrary, but examples thereof include Si, Ge, MgO, and NiO. ｘ , CuO ｘ , ZnS, Al ２ O ３ , ZrO ２ , SiO ２ , TiO ２ , ZnO, and Bi ２ O ３Preferably, the material contains at least one material selected from the group consisting of ZrO ２ By using such a material for the adhesive film, the substrate 30 and the intermediate layer 38 can be properly adhered to each other.

[0080] (Characteristics of the Transparent Member) As described above, the transparent member 20 is formed by forming the first functional film 32 having the outermost layer 34 on the surface 30a of the base material 30. By forming the outermost layer 34, the transparent member 20 can appropriately transmit single-wavelength light and far-infrared rays while appropriately improving scratch resistance.

[0081] The transmittance of the transparent member 20 to 10 μm light is preferably 50% or more, more preferably 65% ​​or more, and even more preferably 70% or more. The average transmittance of the transparent member 20 to light with wavelengths of 8 μm to 12 μm is 50% or more, more preferably 65% ​​or more, and even more preferably 70% or more. When the transmittance and average transmittance are within this range, far infrared rays can be transmitted appropriately.

[0082] The transmittance of the transparent member 20 to single wavelength light is 80% or more, more preferably 85% or more, even more preferably 90% or more, and most preferably 95% or more. When the transmittance is in this range, the single wavelength light can be appropriately transmitted.

[0083] The reflectance of the transparent member 20 for 10 μm light is preferably 20% or less, more preferably 10% or less, and even more preferably 5% or less. Furthermore, the average reflectance of the transparent member 20 for light with wavelengths of 8 μm to 12 μm is preferably 20% or less, more preferably 10% or less, and even more preferably 5% or less. Having the reflectance and average reflectance within these ranges allows for appropriate transmission of far-infrared rays. Note that 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). Reflectance can be measured, for example, using a Fourier transform infrared spectrometer (Nicolet iS10, manufactured by ThermoScientific).

[0084] The reflectance of the transmitting member 20 for single wavelength light is preferably 10% or less, more preferably 5% or less, even more preferably 2% or less, and most preferably 1% or less. When the reflectance is in this range, the single wavelength light can be appropriately transmitted.

[0085] The indentation hardness of the surface 20A (i.e., the surface 34a of the outermost layer 34) on the vehicle exterior side of the transparent member 20 at an indentation depth of 90 to 110 nm is preferably 9.0 GPa or more, more preferably 10.0 GPa or more, more preferably 11.0 GPa or more, even more preferably 12.0 GPa or more, and most preferably 13.0 GPa or more. Having the indentation hardness of the surface 20A within this range allows for appropriate improvement in scratch resistance. The indentation hardness of the surface 20A refers to the indentation hardness (indentation hardness) measured by a nanoindenter using a nanoindenter at an indentation depth of 90 to 110 nm. More specifically, the indentation hardness is a value determined from the displacement-load curve from loading to unloading of the measuring indenter, and is specified in ISO 14577. The indentation hardness can be measured as follows. Specifically, a KLA iMicro nanoindenter is used to continuously measure the indentation depth h (nm) corresponding to the indentation load P (mN) throughout the entire process from the start of loading to unloading at the measurement point, and a P-h curve is created. Then, the indentation hardness H (GPa) is calculated from the created P-h curve using the following equation (4):

[0086] H=P / A...(4)

[0087] In equation (4), P is the indentation load (mN), and A is the projected area of ​​the indenter (μm ２ In this embodiment, the indentation hardness H in the indentation depth range of 90 nm to 110 nm is defined as the indentation hardness of the surface 20A. That is, in this embodiment, it is preferable that the indentation hardness H satisfies the above range in the entire indentation depth range of 90 nm to 110 nm.

[0088] As shown in FIG. 3 , the exterior surface 20A of the transparent member 20 is preferably formed flush (continuous) with the exterior surface of the light-shielding region A2. In other words, the exterior surface 20A of the transparent member 20 is attached so as to be continuous with the surface 12A of the glass substrate 12. By making the surface 20A of the transparent member 20 continuous with the surface 12A of the glass substrate 12 in this manner, the wiping effect of the wiper can be prevented from being impaired. Furthermore, the presence of a step can be prevented from impairing the design of the vehicle V, and the risk of sand and dust accumulating on the step can be reduced. Furthermore, the transparent member 20 is preferably molded to fit the curved surface shape of the vehicle glass 1 to which it is applied. The method for molding the transparent member 20 is not particularly limited, but polishing or molding can be selected depending on the curved surface shape and the member.

[0089] The shape of the transparent 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 transparent member 20 is preferably disc-shaped (cylindrical). From the standpoint of design, the surface shape of the transparent 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 transparent member 20 may be lenticular. This configuration is preferable because it allows the far-infrared light to be efficiently focused even if the area of ​​the transparent member 20 is small. In this case, the number of lens-shaped transparent members 20 is preferably one to three, and typically two. Furthermore, it is particularly preferable that the lens-shaped transparent member 20 is pre-aligned and modularized, and is integrated with a housing or bracket that adheres the far-infrared camera CA1 to the vehicle glass 1.

[0090] 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 shape of the transparent member 20 is also preferably smaller on the vehicle interior surface than 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 (on the vehicle exterior side) and a glass substrate 14 (on the 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 transparent 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.

[0091] As shown in FIG. 3 , the length d1 of the longest straight line connecting any two points on the exterior surface of the transparent member 20 is preferably 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 length d2 of the longest straight line connecting any two points on the exterior surface of the opening 19 in the far-infrared transmitting region B is preferably 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 the length of the longest straight line connecting any two points on the outer periphery of the opening 19 on the exterior surface (surface 12A) of the vehicle glass 1. By setting the length d1 of the transparent member 20 and the length d2 of the opening 19 within this range, 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. Note that, when the shape of the vehicle exterior surface of the transparent 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 in a state in which 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 in a state after bending. The same applies to the descriptions of dimensions and positions other than the lengths d1 and d2 unless otherwise specified.

[0092] (Effects) As described above, the transparent member 20 according to this embodiment includes a substrate 30 that transmits far-infrared rays and a first functional film 32 formed on the substrate 30, and has an average transmittance of 50% or more for light with wavelengths of 8 μm to 12 μm and a transmittance of 80% or more for light from a laser light source emitting light with a wavelength in the range of 0.8 μm to 1.8 μm (single-wavelength light). The outermost layer 34 of the first functional film 32 has a refractive index of 1.7 or more for light from the laser light source (single-wavelength light). Because the 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 and a transmittance of 80% or more for single-wavelength light, it can appropriately transmit light with wavelengths of 8 μm to 12 μm and single-wavelength light with wavelengths of 0.8 μm to 1.8 μm, i.e., light in multiple wavelength bands. Furthermore, the outermost layer 34 of the transparent member 20 has a refractive index of 1.7 or more for single-wavelength light, which is a high refractive index for single-wavelength light, and therefore forms a dense film that appropriately transmits single-wavelength light while improving scratch resistance.

[0093] The transmitting member 20 preferably has an average reflectance of 20% or less for light with wavelengths of 8 μm to 12 μm and a reflectance of 10% or less for single-wavelength light, and is therefore able to appropriately transmit light with wavelengths of 8 μm to 12 μm and single-wavelength light.

[0094] The outermost layer 34 preferably has an extinction coefficient of 0.10 or less for light with a wavelength of 10 μm and an extinction coefficient of 0.10 or less for single wavelength light, thereby allowing appropriate transmission of light with wavelengths of 8 μm to 12 μm and single wavelength light.

[0095] The thickness D2 of the outermost layer 34 is preferably 20 nm or more. By setting the thickness of the outermost layer 34 within this range, it is possible to improve scratch resistance while appropriately transmitting light with a wavelength of 8 μm to 12 μm and single-wavelength light.

[0096] The outermost layer 34 is ZrO ２ It is preferable that the layer contains ZrO as the main component. ２ By using a layer containing this as the main component as the outermost layer 34, it is possible to improve scratch resistance while appropriately transmitting light with wavelengths of 8 μm to 12 μm and single wavelength light.

[0097] The first functional film 32 preferably includes an outermost layer 34 and a contact layer 36 located closer to the substrate 30 than the outermost layer 34 and in contact with the outermost layer 34. The refractive index of the outermost layer 34 for single-wavelength light is preferably higher than the refractive index of the contact layer 36 for single-wavelength light. That is, in the first functional film 32, the low-refractive-index contact layer 36 and the high-refractive-index outermost layer 34 are stacked in this order from the substrate 30 side at the outermost part. Therefore, the first functional film 32 functions appropriately as an anti-reflection film for single-wavelength light, appropriately transmitting the single-wavelength light, while the outermost layer 34 is made into a dense film, thereby improving scratch resistance. In this embodiment, stacking the low-refractive-index layer and the high-refractive-index layer in this order at the outermost part provides sufficient anti-reflection function for single-wavelength light, while the outermost layer 34 is made into a dense high-refractive-index layer, thereby improving scratch resistance.

[0098] The refractive index of the contact layer 36 for single wavelength light is preferably equal to or less than the square root of the refractive index for single wavelength light of the substrate 30. By setting the refractive index of the contact layer 36, which is a low refractive index layer, in this range, sufficient anti-reflection function for single wavelength light can be imparted.

[0099] The refractive index of the substrate 30 with respect to single wavelength light is preferably 1.8 or more and 4.2 or less. By setting the refractive index of the substrate 30 within this range, the single wavelength light can be appropriately transmitted.

[0100] The first functional film 32 preferably includes an outermost layer 34 and an intermediate layer 38 located closer to the substrate 30 than the outermost layer 34. The intermediate layer 38 is a laminate in which a high-refractive index layer 38A and a low-refractive index layer 38B are laminated in this order from the substrate 30 side, and the refractive index of the high-refractive index layer 38A for single-wavelength light is preferably higher than the refractive index of the low-refractive index layer 38B for single-wavelength light. By making the intermediate layer 38 a laminate in which the high-refractive index layer 38A and the low-refractive index layer 38B are laminated in this order, light with a wavelength of 8 μm to 12 μm and single-wavelength light can be appropriately transmitted.

[0101] Intermediate layer 38 is a laminate in which low refractive index layer 38B and high refractive index layer 38A are laminated in this order from the substrate 30 side, and the refractive index of high refractive index layer 38A for single wavelength light is preferably higher than the refractive index of low refractive index layer 38B for single wavelength light. By making intermediate layer 38 a laminate in which low refractive index layer 38B and high refractive index layer 38A are laminated in this order, light with a wavelength of 8 μm to 12 μm and single wavelength light can be appropriately transmitted.

[0102] EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Table 1 shows the layered structure of the transparent member of each example, and Table 2 shows the evaluation results of the transparent member of each example. In the examples, an optical simulation of the transparent member was carried out. The optical simulation was carried out using simulation software (TFCalc, manufactured by Hulinks Co., Ltd.). In this example, the wavelength dispersion of the refractive index was not taken into consideration, and the optical simulation was carried out assuming that the extinction coefficient k of each layer was 0. However, adjustments may be made taking into consideration the wavelength dispersion of the refractive index and the extinction coefficient.

[0103]

[0104] (Example 1) In Example 1, a model of a transparent member having functional films formed on both sides of a substrate was used. In Example 1, the target single wavelength light was set to 1550 nm, and the substrate was set to have a refractive index of 2.16 for light with a wavelength of 10 μm and a refractive index of 2.26 for light with a wavelength of 1550 nm, and a thickness of 2 mm, so that the substrate would reproduce ZnS (multispectral grade). Patent Document 1 was used as a reference for the functional film, and a high refractive index layer (MgO), a low refractive index layer (MgF ２ A total of six layers were provided in this order: a high refractive index layer, a low refractive index layer, and a low refractive index layer. The refractive indices and thicknesses of the high refractive index layer, the low refractive index layer, and the substrate were as shown in Table 1.

[0105] (Example 2) In Example 2, the refractive index of the substrate for light with a wavelength of 10 μm was set to 3.97, the refractive index for light with a wavelength of 1550 nm was set to 4.04, and the thickness was set to 5 mm so that the substrate would reproduce Ge. ３), high refractive index layer (ZnSe), high refractive index layer (Ge), high refractive index layer (ZnSe), low refractive index layer (YbF ３ Example 2 differs from Example 1 in that a total of six layers were provided in this order, with the high refractive index layer (ZnSe) as the outermost layer. The refractive indices and thicknesses of the high refractive index layer, low refractive index layer, and substrate in Example 2 were as shown in Table 1.

[0106] (Example 3) In Example 3, a total of five layers were provided in the order of a high refractive index layer, a low refractive index layer, a high refractive index layer, and so on from the substrate side, and the outermost layer was a high refractive index layer (ZrO ２ The refractive indexes and thicknesses of the high refractive index layer, the low refractive index layer and the substrate in Example 3 are shown in Table 1.

[0107] (Example 4) In Example 4, a total of seven layers were provided in the order of a high refractive index layer, a low refractive index layer, a high refractive index layer, and so on from the substrate side, and the outermost layer was a high refractive index layer (ZrO ２ The refractive indexes and thicknesses of the high refractive index layer, the low refractive index layer and the substrate in Example 4 are shown in Table 1.

[0108] (Example 5) In Example 5, the high refractive index layer was made of ZrO ２ Example 5 differs from Example 1 in that a total of eight layers were provided in the order of a low refractive index layer, a high refractive index layer, a low refractive index layer, and so on from the substrate side, with the outermost layer being a high refractive index layer. The refractive indices and thicknesses of the high refractive index layer, low refractive index layer, and substrate in Example 5 are shown in Table 1.

[0109] Example 6 differs from Example 1 in that a total of five layers were provided in the order of a low refractive index layer, a high refractive index layer, a low refractive index layer, and so on from the substrate side, with the outermost layer being a high refractive index layer (DLC). The refractive indices and thicknesses of the high refractive index layer, low refractive index layer, and substrate in Example 6 were as shown in Table 1.

[0110] (Example 7) In Example 7, the refractive index of the substrate for light with a wavelength of 10 μm was set to 3.40, the refractive index for light with a wavelength of 1550 nm was set to 3.46, and the thickness was set to 2 mm so that the substrate would reproduce Si (FZ grade). ２Example 7 differs from Example 1 in that a total of seven layers were provided in the order of a high refractive index layer, a low refractive index layer, a high refractive index layer, and so on from the substrate side, with the outermost layer being a high refractive index layer. The refractive indices and thicknesses of the high refractive index layer, low refractive index layer, and substrate in Example 7 are shown in Table 1.

[0111] (Example 8) In Example 8, the target single wavelength light was 905 nm, and a total of seven layers were provided in the order of a high refractive index layer, a low refractive index layer, a high refractive index layer, and so on from the substrate side, with the outermost layer being a high refractive index layer (ZrO ２ The refractive indexes and thicknesses of the high refractive index layer, the low refractive index layer and the substrate in Example 8 are shown in Table 1.

[0112] (Example 9) In Example 9, the target single wavelength light was 1350 nm, and a total of seven layers were provided in the order of a high refractive index layer, a low refractive index layer, a high refractive index layer, and so on from the substrate side, with the outermost layer being a high refractive index layer (ZrO ２ The refractive indexes and thicknesses of the high refractive index layer and the low refractive index layer in Example 9 are shown in Table 1.

[0113] (Example 10) In Example 10, the target single wavelength light was set to 1550 nm, and a high refractive index layer (Si), a high refractive index layer (ZrO ２ ), high refractive index layer (Si), high refractive index layer (ZrO ２ ) ... in this order, a total of six layers are provided, with the outermost layer being a high refractive index layer (ZrO ２ The refractive index and thickness of the high refractive index layer in Example 10 are shown in Table 1.

[0114] For each example of the transparent member, the scratch resistance of the outermost layer, the transmittance and reflectance of the transparent member for light of 1550 nm, 905 nm, or 1350 nm, and the average transmittance and average reflectance of the transparent member for light of 8 μm to 12 μm were calculated by simulation. The reflectance and transmittance of the transparent member for light of each wavelength were calculated using simulation software (TFCalc, manufactured by Hulinks Co., Ltd.). Figure 8 is a graph showing the simulation results of the visible and near-infrared transmission spectra of Examples 2 and 4. Figure 9 is a graph showing the simulation results of the visible and near-infrared reflection spectra of Examples 2 and 4. Figure 10 is a graph showing the simulation results of the far-infrared transmission spectra of Examples 2 and 4. Figure 11 is a graph showing the simulation results of the far-infrared reflection spectra of Examples 2 and 4. 8 to 11, lines LA2, LB2, LC2, and LD2 represent the results of Example 2, and lines LA4, LB4, LC4, and LD4 represent the results of Example 4.

[0115] Table 2 shows, for each example, the substrate material simulated in the simulation, the material of the outermost layer simulated in the simulation, the refractive index of the outermost layer for single-wavelength light, the film thickness of the outermost layer, the average refractive index of the functional film (corresponding to the average refractive index of the first functional film 32 described in this embodiment), the transmittance and reflectance for the target single-wavelength light, and the average transmittance and average reflectance for light of 8 μm to 12 μm. As shown in Table 2, Example 1, which is a comparative example, has a refractive index of less than 1.7, which is presumed to have low scratch resistance. In Example 2, which is a comparative example, the refractive index of the outermost layer is 1.7 or higher, but it can be seen that the transmittance for light of 1550 nm is low. On the other hand, in Examples 3 to 10, which are working examples, the refractive index of the outermost layer is 1.7 or more, the transmittance for light of 1550 nm, 905 nm, or 1350 nm is 80% or more, and the average transmittance for light of 8 μm to 12 μm is 50% or more. Therefore, it is clear that a highly durable film that can transmit light in multiple wavelength bands and has high scratch resistance can be applied.

[0116] 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.

[0117] REFERENCE SIGNS LIST 1 Vehicle glass 10, 12, 14 Glass base 20 Transmitting member 30 Base material 32 First functional film (functional film) 34 Outermost layer 36 Contact layer 38 Intermediate layer 38A High refractive index layer 38B Low refractive index layer

Claims

1. The present invention includes a substrate that transmits far-infrared rays and a functional film formed on the substrate, The average transmittance of light having a wavelength of 8 μm to 12 μm is 50% or more, The transmittance of light from a laser light source emitting light in the wavelength range of 0.8 μm to 1.8 μm is 80% or more; the outermost layer of the functional film has a refractive index of 1.7 or more with respect to the light from the laser light source and is a layer containing ZrO 2 as a main component; Transparent material.

2. 2. The transparent member according to claim 1, wherein the average reflectance of light having a wavelength of 8 μm to 12 μm is 20% or less, and the reflectance of light from the laser light source is 10% or less.

3. 3. The transparent member according to claim 1, wherein the outermost layer has an extinction coefficient of 0.10 or less for light with a wavelength of 10 μm and an extinction coefficient of 0.10 or less for light from the laser light source.

4. The transmission member according to claim 1 or 2, wherein the outermost layer has a thickness of 20 nm or more.

5. the functional film includes the outermost layer and a contact layer located closer to the substrate than the outermost layer and in contact with the outermost layer, 3. The transparent member according to claim 1, wherein a refractive index of the outermost layer for the light from the laser light source is higher than a refractive index of the contact layer for the light from the laser light source.

6. the functional film includes the outermost layer and a contact layer located closer to the substrate than the outermost layer and in contact with the outermost layer, 3. The transparent member according to claim 1, wherein a refractive index of the contact layer for the light from the laser light source is equal to or less than a square root of a refractive index of the base material for the light from the laser light source.

7. The transparent member according to claim 1 or 2, wherein the refractive index of the base material with respect to the light from the laser light source is 1.8 or more and 4.2 or less.

8. the functional film includes the outermost layer and an intermediate layer located closer to the substrate than the outermost layer, 3. The transparent member according to claim 1, wherein the intermediate layer is a laminate in which a high refractive index layer and a low refractive index layer are laminated in this order from the base material side, and a refractive index of the high refractive index layer with respect to the light from the laser light source is higher than a refractive index of the low refractive index layer with respect to the light from the laser light source.

9. the functional film includes the outermost layer and an intermediate layer located closer to the substrate than the outermost layer, 3. The transparent member according to claim 1, wherein the intermediate layer is a laminate in which a low refractive index layer and a high refractive index layer are laminated in this order from the substrate side, and a refractive index of the high refractive index layer with respect to the light from the laser light source is higher than a refractive index of the low refractive index layer with respect to the light from the laser light source.

10. 3. The transparent member according to claim 1, wherein the functional film has an average refractive index of 1.3 or more and 2.5 or less for light having a wavelength of 10 μm.

11. The transparent member according to claim 1 or 2, which is mounted on a vehicle.

12. The transparent member according to claim 11 , which is disposed in a window member of a vehicle.

13. The transparent member according to claim 11 , which is disposed in an exterior member for a pillar of a vehicle.

14. The transparent member according to claim 11 , which is disposed in a light-shielding area of ​​a vehicle exterior member.