Far infrared transmitting member and method for manufacturing far infrared transmitting member

Abstract

The present application suitably transmits far infrared rays and ensures design properties. A far infrared ray transmitting member (20) includes a far infrared ray transmitting base material (30) and a functional film (31) formed on the base material (30), and the far infrared ray transmitting member (20) has a variance of the reflectance in increments of 1 nm for light in the range of wavelengths of 360 nm to 830 nm of 30 or less, a visible light reflectance specified in JIS R3106 of 25% or less, and an average transmittance for light in the range of wavelengths of 8 μm to 12 μm of 50% or more.

Description

Technical Field

[0001] This invention relates to far-infrared transmission components and methods for manufacturing far-infrared transmission components. Background Technology

[0002] For example, when installing far-infrared sensors on vehicles, far-infrared transmission components are sometimes provided, which have anti-reflection films formed to suppress far-infrared reflection and increase the amount of transmitted light, so that far-infrared light is appropriately incident into the far-infrared sensor. For example, Patent Document 1 describes the use of an infrared transmission film with an extinction coefficient of 0.4 or less in the far-infrared region in an automotive imaging device. In addition, Non-Patent Documents 1 and 2 describe the formation of a NiO film on a Si substrate as an infrared anti-reflection film.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-151408

[0006] Non-patent document 1: Hyun Bin Shim et al., Controlling the infrared opticalproperties of rf-sputtered NiO films for application of infrared window, Infrared Physics and Technology 72(2015), 135-139

[0007] Non-Patent Literature 2: Hyun Bin Shim et al., Nickel oxide film as an AR coating of Si window for IR sensor packaging, Infrared Technology and applications XXXIX, Proc. of SPIE Vol. 8704 870420-1 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] Such far-infrared transmitting components, for example, when installed in a way that exposes them to the outside, are preferably inconspicuous from an aesthetic design point of view. Therefore, there is a need for a far-infrared transmitting component that appropriately transmits far-infrared rays while ensuring aesthetic design.

[0010] The purpose of this invention is to provide a far-infrared transmitting component that appropriately transmits far-infrared rays while ensuring aesthetic design, and a method for manufacturing the far-infrared transmitting component.

[0011] means for solving problems

[0012] To solve the above problems and achieve the objective, the far-infrared transmission component disclosed herein is a far-infrared transmission component comprising a substrate for transmitting far-infrared rays and a functional film formed on the substrate, wherein the far-infrared transmission component has a variance of reflectance in increments of 1 nm for light in the wavelength range of 360 nm to 830 nm of 30 or less, a visible light reflectance of 25% or less as specified in JIS R 3106, and an average transmittance of 50% or more for light in the wavelength range of 8 μm to 12 μm.

[0013] To solve the above problems and achieve the objective, in the method for manufacturing a far-infrared transmission component disclosed herein, a far-infrared transmission component is manufactured by forming a functional film on a far-infrared transmission substrate. The far-infrared transmission component has a variance of reflectance in increments of 1 nm for light in the wavelength range of 360 nm to 830 nm of 30 or less, a visible light reflectance of 25% or less as specified in JISR 3106, and an average transmittance of 50% or more for light in the wavelength range of 8 μm to 12 μm.

[0014] Invention Effects

[0015] According to the present invention, far-infrared rays can be appropriately transmitted while ensuring aesthetic design. Attached Figure Description

[0016] Figure 1 This is a schematic diagram showing the state in which the vehicle glass of this embodiment is mounted on a vehicle.

[0017] Figure 2 This is a plan view of the vehicle glass 1 according to the first embodiment.

[0018] Figure 3 For along Figure 2 A cross-sectional view along line AA.

[0019] Figure 4 For along Figure 2 A sectional view of section BB.

[0020] Figure 5 This is a cross-sectional schematic diagram of the far-infrared transmission component of this embodiment.

[0021] Figure 6 This is a cross-sectional schematic diagram of a far-infrared transmission component, which is another example of this embodiment.

[0022] Figure 7 This is a cross-sectional schematic diagram of a far-infrared transmission component, which is another example of this embodiment.

[0023] Figure 8 A graph showing the evaluation results for each example.

[0024] Figure 9 A graph showing the evaluation results for each example. Detailed Implementation

[0025] Hereinafter, suitable embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to these embodiments; furthermore, in the case of multiple embodiments, it also includes configurations by combining various embodiments. Additionally, numerical values ​​include rounding ranges.

[0026] (vehicle)

[0027] Figure 1 This is a schematic diagram illustrating the state in which the vehicle glass of this embodiment is mounted on a vehicle. For example... Figure 1 As shown, the vehicle glass 1 of this embodiment is mounted on a vehicle V. The vehicle glass 1 is a window component applied to the front windshield of the vehicle V. That is, the vehicle glass 1 is used as the front window of the vehicle V, in other words, it is used as a windshield. An infrared camera CA1 and a visible light camera CA2 are mounted inside the vehicle V (interior). It should be noted that the interior of the vehicle V (interior) refers to, for example, the driver's seat room where the driver is located.

[0028] The camera unit 100 of this embodiment comprises vehicle glass 1, a far-infrared camera CA1, and a visible light camera CA2. The far-infrared camera CA1 is a camera that detects far-infrared radiation and captures a thermal image of the exterior of the vehicle V by detecting far-infrared radiation 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. It should be noted that, in addition to the far-infrared camera CA1 and the visible light camera CA2, the camera unit 100 may also include, for example, LiDAR or millimeter-wave radar. Here, far-infrared radiation refers to electromagnetic waves in the wavelength range of, for example, 8μm to 13μm, and visible light refers to electromagnetic waves in the wavelength range of, for example, 360nm to 830nm. Furthermore, 8μm to 13μm here refers to 8μm or more and 13μm or less, and 360nm to 830nm refers to 360nm or more and 830nm or less, and the same applies thereafter. It should be noted that far-infrared radiation can be set to electromagnetic waves in the wavelength range of 8μm to 12μm.

[0029] (Vehicle glass)

[0030] Figure 2This is a plan view of the vehicle glass 1 according to the first embodiment. Figure 3 For along Figure 2 A cross-sectional view along line AA. Figure 4 For along Figure 2 A sectional view of section BB. (e.g.) Figure 2 As shown, the upper edge of the vehicle glass 1 is referred to as upper edge 1a, the lower edge of the vehicle glass 1 as lower edge 1b, one side edge of the vehicle glass 1 as side edge 1c, and the other side edge of the vehicle glass 1 as side edge 1d. Upper edge 1a is the edge portion located vertically upward when the vehicle glass 1 is mounted on the vehicle V. Lower edge 1b is the edge portion located vertically downward when the vehicle glass 1 is mounted on the vehicle V. Side edge 1c is the edge portion located on one side of the vehicle glass 1 when it is mounted on the vehicle V. Side edge 1d is the edge portion located on the other side of the vehicle glass 1 when it is mounted on the vehicle V.

[0031] Hereinafter, in the direction parallel to the surface of the vehicle glass 1, the direction from the upper edge 1a to the lower edge 1b is defined as the Y direction, and the direction from the side edge 1c to the side edge 1d is defined as the X direction. In this embodiment, the X direction is orthogonal to the Y direction. The direction orthogonal to the surface of the vehicle glass 1, i.e., the thickness direction of the vehicle glass 1, is defined as the Z direction. The Z direction is, for example, the direction from the outside of the vehicle V to the inside of the vehicle V when the vehicle glass 1 is mounted on the vehicle V. The X and Y directions are along the surface of the vehicle glass 1, but for example, if the surface of the vehicle glass 1 is curved, they can also 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 refers to the center position of the vehicle glass 1 when viewed from the Z direction.

[0032] A light-transmitting area A1 and a light-blocking area A2 are formed on the vehicle glass 1. The light-transmitting area A1 occupies the central portion of the vehicle glass 1 when viewed from the Z direction. The light-transmitting area A1 is used to ensure the driver's field of vision. The light-transmitting area A1 transmits visible light. The light-blocking area A2 is formed around the light-transmitting area A1 when viewed from the Z direction. The light-blocking area A2 blocks visible light. Within the light-blocking area A2a, which is part of the upper edge 1a, a far-infrared transmission area B and a visible light transmission area C are formed.

[0033] The far-infrared transmission region B is the area that transmits far-infrared light, and it is also the area where the far-infrared camera CA1 is installed. That is, the far-infrared camera CA1 is positioned where it overlaps with the far-infrared transmission region B when viewed from the optical axis of the far-infrared camera CA1. The visible light transmission region C is the area that transmits visible light, and it is also the area where the visible light camera CA2 is installed. That is, the visible light camera CA2 is positioned where it overlaps with the visible light transmission region C when viewed from the optical axis of the visible light camera CA2.

[0034] Because a far-infrared transmission area B and a visible light transmission area C are formed in the light-shielding area A2, the light-shielding area A2 blocks far-infrared rays in areas other than the area where the far-infrared transmission area B is formed, and blocks visible light in areas other than the area where the visible light transmission area C is formed. A light-shielding area A2a is formed around the far-infrared transmission area B and the visible light transmission area C. By setting the light-shielding area A2a around them in this way, various sensors can be protected from the influence of sunlight, which is therefore preferred. Since the wiring of various sensors is not visible from outside the vehicle, this is also preferred from an aesthetic design point of view.

[0035] like Figure 3 As shown, the vehicle glass 1 has a glass substrate 12 (first glass substrate), a glass substrate 14 (second glass substrate), an intermediate layer 16, and a light-shielding layer 18. In the vehicle glass 1, the glass substrate 12, the intermediate layer 16, the glass substrate 14, and the light-shielding layer 18 are sequentially stacked in the Z direction. The glass substrate 12 and the glass substrate 14 are fixed to each other (adhesive-bonded) by the intermediate layer 16.

[0036] As the glass substrates 12 and 14, for example, soda-lime glass, borosilicate glass, aluminosilicate glass, etc., can be used. The interlayer 16 is an adhesive layer that bonds the glass substrates 12 and 14 together. As the interlayer 16, for example, polyvinyl butyral (hereinafter also referred to as PVB) modified materials, ethylene-vinyl acetate copolymer (EVA) materials, polyurethane resin materials, vinyl chloride resin materials, etc., can be used. More specifically, the glass substrate 12 includes one surface 12A and another surface 12B, the other surface 12B being in contact with and fixed (adheded) to one surface 16A of the interlayer 16. The glass substrate 14 includes one surface 14A and another surface 14B, one surface 14A being in contact with and fixed (adheded) to the other surface 16B of the interlayer 16. In this way, the vehicle glass 1 is a laminated glass obtained by laminating the glass substrates 12 and 14. However, the vehicle glass 1 is not limited to laminated glass; for example, it may be a structure containing only one of the glass substrate 12 and the glass substrate 14. In this case, the intermediate layer 16 may not be provided. Hereinafter, without distinguishing between the glass substrates 12 and 14, it will be referred to as the glass substrate 10.

[0037] The light-shielding layer 18 includes one surface 18A and another surface 18B, with one surface 18A 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 18. For example, a ceramic layer containing conventionally known materials, such as a black ceramic layer, can be used. For example, a light-shielding polyethylene terephthalate (PET) film, a light-shielding polyethylene naphthalate (PEN) film, or a light-shielding polymethyl methacrylate (PMMA) film can be used.

[0038] In this embodiment, the side of the vehicle glass 1 where the light-shielding layer 18 is provided is the inner side (interior side) of the vehicle V, and the side of the vehicle glass 1 where the glass substrate 12 is provided is the outer side (outer side) of the vehicle V. However, it is not limited to this, and the light-shielding layer 18 may also be the outer side of the vehicle V. When the glass is made of laminated glass composed of glass substrates 12 and 14, the light-shielding layer 18 may be formed between the glass substrate 12 and the glass substrate 14.

[0039] (Shaded area)

[0040] The light-shielding region A2 is formed by providing a light-shielding layer 18 on the glass substrate 10. That is, the light-shielding region A2 is the region of the glass substrate 10 where the light-shielding layer 18 is present. Specifically, the light-shielding region A2 is the region where the glass substrate 10 is stacked with the glass substrate 12, the intermediate layer 16, the glass substrate 14, and the light-shielding layer 18. On the other hand, the light-transmitting region A1 is the region of the glass substrate 10 where the light-shielding layer 18 is not present. Specifically, the light-transmitting region A1 is the region where the glass substrate 12, the intermediate layer 16, and the glass substrate 14 are stacked, but the light-shielding layer 18 is not stacked.

[0041] (Far-infrared transmission area)

[0042] like Figure 3 As shown, the vehicle glass 1 has an opening 19 extending from one surface (surface 12A) in the Z direction to another surface (surface 14B). A far-infrared transmitting member 20 is disposed within the opening 19. The area where the opening 19 is formed and the far-infrared transmitting member 20 is disposed is the far-infrared transmitting region B. That is, the far-infrared transmitting region B is the area where the opening 19 is provided and the far-infrared transmitting member 20 is disposed within the opening 19. Since the light-shielding layer 18 does not transmit far-infrared rays, the light-shielding layer 18 is not provided in the far-infrared transmitting region B. That is, in the far-infrared transmitting region B, the glass substrate 12, the intermediate layer 16, the glass substrate 14, and the light-shielding layer 18 are not provided; instead, the far-infrared transmitting member 20 is provided in the formed opening 19. The far-infrared transmitting member 20 will be described later.

[0043] (Visible light transmission region)

[0044] like Figure 4 As shown, similar to the light-transmitting region A1, the visible light transmission region C is the region in the Z direction where the glass substrate 10 does not have a light-shielding layer 18. That is, the visible light transmission region C is the region where the glass substrate 12, the intermediate layer 16, and the glass substrate 14 are stacked, but the light-shielding layer 18 is not stacked.

[0045] like Figure 2As shown, 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, viewed from the Z direction, is designated as the center point OB, and the center of the visible light transmission region C, viewed from the Z direction, is designated as the center point OC. When the shortest distance between the far-infrared transmission region B (opening 19) and the visible light transmission region C, 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 10 mm or more and 80 mm or less. By positioning the visible light transmission region C relative to the far-infrared transmission region B within this range, images of close proximity can be captured using the far-infrared camera CA1 and the visible light camera CA2, while perspective distortion in the visible light transmission region C can be suppressed, thereby enabling the visible light camera CA2 to capture images appropriately. By capturing images of close proximity using the far-infrared camera CA1 and the visible light camera CA2, the processing load on the data obtained from each camera can be reduced, and the wiring of power and signal cables becomes more appropriate.

[0046] like Figure 2 As shown, the visible light transmission region C and the far-infrared transmission region B are preferably arranged along the X direction. That is, the visible light transmission region C is preferably arranged along the X direction with the far-infrared transmission region B, and not located on the Y-direction side of the far-infrared transmission region B. By arranging the visible light transmission region C in a manner that aligns it with the far-infrared transmission region B along the X direction, the visible light transmission region C can be positioned near the upper edge 1a. Therefore, the driver's field of vision in the light-transmitting region A1 can be adequately ensured.

[0047] (Far-infrared transmission component)

[0048] The far-infrared transmission component 20, which is set in the far-infrared transmission area B, will be described in detail below. Figure 5 This is a cross-sectional schematic diagram of the far-infrared transmission component of this embodiment. Figure 5As shown, the far-infrared transmission member 20 has a substrate 30 and a functional film 31 formed on the substrate 30. In this embodiment, the far-infrared transmission member 20 has the functional film 31 formed on both one surface 30a and the other surface 30b of the substrate 30. Surface 30a is the inner side of the vehicle when mounted on the vehicle glass 1, and surface 30b is the outer side of the vehicle when mounted on the vehicle glass 1. However, the far-infrared transmission member 20 is not limited to having the functional film 31 formed on both surfaces 30a and 30b of the substrate 30; it may also have the functional film 31 formed on at least one of the surfaces 30a and 30b. The functional film 31 is preferably formed on at least the outer surface 30b of the surfaces 30a and 30b. That is, it can be said that no film may be formed on the surface 30a of the substrate 30, or a film other than the functional film 31 may be formed.

[0049] In this embodiment, the far-infrared transmission member 20 is provided in the light-shielding area A2 of the vehicle glass 1, which serves as a window member of the vehicle V. However, it is not limited to this and can also be provided on any exterior part of the vehicle V, such as the exterior trim piece for the pillars. Furthermore, the far-infrared transmission member 20 is not limited to being provided on the vehicle V and can be used for any purpose.

[0050] (Substrate)

[0051] The substrate 30 is a component capable of transmitting far-infrared light. The internal transmittance of the substrate 30 for light (far-infrared light) with a wavelength of 10 μm is preferably 50% or more, more preferably 60% or more, and even more preferably 70% or more. Furthermore, the average internal transmittance of the substrate 30 for light (far-infrared light) with wavelengths of 8 μm to 12 μm is preferably 50% or more, more preferably 60% or more, and even more preferably 70% or more. By ensuring that the internal transmittance of the substrate 30 for light with a wavelength of 10 μm and the average internal transmittance for light with wavelengths of 8 μm to 12 μm are within this range, far-infrared light can be appropriately transmitted, thereby, for example, fully utilizing the performance of the far-infrared camera CA1. It should be noted that the average internal transmittance here refers to the average internal transmittance of light at various wavelengths within this band (here, 8 μm to 12 μm).

[0052] The internal transmittance of the substrate 30, after deducting the surface reflection losses on the incident and emanating sides, is well known in the art and can be measured using conventional methods. The measurement is performed, for example, as follows.

[0053] Prepare a pair of flat specimens (first specimen and second specimen) with the same substrate composition but different thicknesses. The two sides of the flat specimens are parallel planes that have been optically polished. Let the external transmittance of the first specimen including surface reflection loss be T1, the external transmittance of the second specimen including surface reflection loss be T2, the thickness of the first specimen be Td1 (mm), and the thickness of the second specimen be Td2 (mm), where Td1 < Td2. Then, the internal transmittance τ at a thickness Tdx (mm) can be calculated by the following formula (1).

[0054] τ=exp[-Tdx×(lnT1-lnT2) / ΔTd]……(1)

[0055] It should be noted that the external transmittance of infrared radiation can be measured, for example, using a Fourier transform infrared spectrometer (manufactured by ThermoScientific, trade name: Nicolet iS10).

[0056] The refractive index of the substrate 30 for light with a wavelength of 10 μm is preferably 1.5 or higher and 4.0 or lower, more preferably 2.0 or higher and 4.0 or lower, and even more preferably 2.2 or higher and 3.5 or lower. Furthermore, the average refractive index of the substrate 30 for light with wavelengths from 8 μm to 12 μm is preferably 1.5 or higher and 4.0 or lower, more preferably 2.0 or higher and 4.0 or lower, and even more preferably 2.2 or higher and 3.5 or lower. With the refractive index and average refractive index of the substrate 30 within this range, far-infrared light can be appropriately transmitted, thereby, for example, fully utilizing the performance of the far-infrared camera CA1. It should be noted that the average refractive index here refers to the average value of the refractive index of light at various wavelengths in this 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 ellipsometer (manufactured by JAWoollam, IR-VASE-UT) and a spectroscopic transmission spectrum obtained from a Fourier transform infrared spectroscopy device.

[0057] The thickness d0 of the substrate 30 is preferably 0.5 mm or more and 5 mm or less, more preferably 1 mm or more and 4 mm or less, and even more preferably 1.5 mm or more and 3 mm or less. Within this thickness range, strength can be ensured while allowing appropriate transmission of far-infrared rays. It should be noted that the thickness d0 can also be described as the length in the Z direction from surface 30a to surface 30b of the substrate 30.

[0058] There are no particular limitations on the material of the substrate 30; examples include Si, Ge, ZnS, and chalcogenide glasses. It can be said that the substrate 30 preferably contains at least one material selected from the group consisting of Si, Ge, ZnS, and chalcogenide glasses. By using such a material in the substrate 30, far-infrared rays can be appropriately transmitted.

[0059] The preferred composition of chalcogenide glass is as follows:

[0060] Expressed in atomic percent, it contains:

[0061] Ge+Ga: 7%~25%,

[0062] Sb: 0%–35%

[0063] Bi: 0%–20%

[0064] Zn: 0%–20%

[0065] Sn: 0%–20%

[0066] Si: 0%–20%

[0067] La: 0%–20%

[0068] S+Se+Te: 55%~80%

[0069] Ti: 0.005%~0.3%

[0070] Li+Na+K+Cs: 0%~20%

[0071] F + Cl + Br + I: 0% to 20%. Furthermore, this glass preferably has a glass transition temperature (Tg) of 140°C to 550°C.

[0072] It should be noted that Si or ZnS is more preferably used as the material for the substrate 30.

[0073] (Functional membrane)

[0074] The functional film 31 is a film formed on the substrate 30 and used to suppress the reflection of visible light and far-infrared rays.

[0075] like Figure 5 As shown, the functional film 31 of this embodiment includes a visible light absorption layer 32, a high refractive index layer 36, and a low refractive index layer 38. Figure 5In this example, a high-refractive-index layer 36 and a low-refractive-index layer 38 are alternately stacked between the substrate 30 and the visible light absorbing layer 32. That is, within the functional film 31, the visible light absorbing layer 32 is formed on the outermost side (the side furthest from the substrate 30). However, the visible light absorbing layer 32 is not limited to being formed on the outermost side within the functional film 31; a high-refractive-index layer 36 or a low-refractive-index layer 38 may also be formed on the outer side of the visible light absorbing layer 32.

[0076] exist Figure 5 In the example, the functional film 31 has a high refractive index layer 36, a low refractive index layer 38, and a visible light absorbing layer 32 sequentially stacked on the substrate 30 in a direction away from the substrate 30. Hereinafter, the surface of the high refractive index layer 36 opposite to the substrate 30 is designated as surface 36a, the surface of the high refractive index layer 36 on the substrate 30 side is designated as surface 36b, the surface of the low refractive index layer 38 opposite to the substrate 30 is designated as surface 38a, the surface of the low refractive index layer 38 on the substrate 30 side is designated as surface 38b, the surface of the visible light absorbing layer 32 opposite to the substrate 30 is designated as surface 32a, and the surface of the visible light absorbing layer 32 on the substrate 30 side is designated as surface 32b. That is, in Figure 5 In the example, the surface 36b of the high refractive index layer 36 becomes the surface 31b on the substrate 30 side of the functional film 31, and the surface 32a of the visible light absorbing layer 32 becomes the surface 31a on the opposite side of the functional film 31 from the substrate 30. However, in a structure including the visible light absorbing layer 32, the high refractive index layer 36, and the low refractive index layer 38, the layer formed on the side closest to the substrate 30 is not limited to the high refractive index layer 36; for example, it can also be 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 can be sequentially stacked in a direction away from the substrate 30.

[0077] In addition, Figure 5In the example, the functional film 31 has a structure consisting of a high-refractive-index layer 36, a low-refractive-index layer 38, and a visible light absorbing layer 32, but it is not limited to this; it may also have at least one of multiple high-refractive-index layers 36 and low-refractive-index layers 38. For example, the far-infrared transmission member 20 may have multiple high-refractive-index layers 36 and multiple low-refractive-index layers 38 alternately stacked on the substrate 30 in a direction away from the substrate 30, with the visible light absorbing layer 32 on the outermost side (the side furthest from the substrate 30). That is, the substrate 30, high-refractive-index layer 36, low-refractive-index layer 38, high-refractive-index layer 36, ..., low-refractive-index layer 38, and visible light absorbing layer 32 may be stacked sequentially. Furthermore, the far-infrared transmission member 20 may have high-refractive-index layers 36 and low-refractive-index layers 38 alternately stacked on the substrate 30 in a direction away from the substrate 30, with the visible light absorbing layer 32 on the outermost side. 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 absorption layer 32 can be stacked sequentially.

[0078] Alternatively, the functional film 31 can be a layer structure comprising a visible light absorbing layer 32 and a high refractive index layer 36, but excluding a 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) with a refractive index lower than that of the high refractive index layer 36. The functional film 31 may have one high refractive index layer 36 and one visible light absorbing layer 32 sequentially stacked on the substrate 30 in a direction away from the substrate 30, or it may have one visible light absorbing layer 32 and one high refractive index layer 36 sequentially stacked. Furthermore, the functional film 31 may have at least one of multiple visible light absorbing layers 32 and high refractive index layers 36. In this case, for example, the functional film 31 is alternately stacked with a visible light absorbing layer 32 and a high refractive index layer 36, and the high refractive index layer 36, the visible light absorbing layer 32, the high refractive index layer 36, ... the visible light absorbing layer 32 can be stacked sequentially on the substrate 30 in the direction away from the substrate 30, or the visible light absorbing layer 32, the high refractive index layer 36, ... the visible light absorbing layer 32 can be stacked sequentially.

[0079] Alternatively, the functional film 31 can be a layer structure comprising a visible light absorbing layer 32 and a low refractive index layer 38, but excluding a 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) with a refractive index higher than that of the low refractive index layer 38. The functional film 31 may have one visible light absorbing layer 32 and one low refractive index layer 38 sequentially stacked on the substrate 30 in a direction away from the substrate 30, or it may have one low refractive index layer 38 and one visible light absorbing layer 32 sequentially stacked. Furthermore, the functional film 31 may have at least one of multiple visible light absorbing layers 32 and low refractive index layers 38. In this case, for example, the functional film 31 may be alternately stacked with a visible light absorbing layer 32 and a low refractive index layer 38, and the visible light absorbing layer 32, the low refractive index layer 38, the visible light absorbing layer 32, ..., the low refractive index layer 38 may be stacked sequentially on the substrate 30 in the direction away from the substrate 30, or the low refractive index layer 38, the visible light absorbing layer 32, ..., the low refractive index layer 38 may be stacked sequentially.

[0080] In the case of multilayer stacking as described above, considering the refractive index of the substrate and its adhesion to the substrate, the layer of the functional film 31 closest to the substrate 30 is either a visible light absorbing layer 32, a high refractive index layer 36, or a low refractive index layer 38. By stacking multiple visible light absorbing layers 32, high refractive index layers 36, and low refractive index layers 38 in this way, it is possible to suppress the reflectivity of light over a wider wavelength range.

[0081] Furthermore, the functional film 31 can be characterized by the fact that it may not include both the high-refractive-index layer 36 and the low-refractive-index layer 38, and it has at least one visible light absorbing layer 32. That is, the functional film 31 can be a single-layer film composed of a single visible light absorbing layer 32, or it can be a multilayer film obtained by laminating the visible light absorbing layer 32 with at least one of the high-refractive-index layer 36 and the low-refractive-index layer 38. By making the functional film 31 into a multilayer antireflection film, low reflectivity can be easily achieved over a wide wavelength range by utilizing the interface reflection light generated at each interface and the interference effect of light. In the multilayer functional film 31, the visible light absorbing layer 32 is preferably disposed on the outermost side of the substrate 30.

[0082] Furthermore, the functional film 31 formed on the inner side of the substrate 30 and the functional film 31 formed on the outer side of the substrate 30 can have different layer structures.

[0083] (Visible light absorption layer)

[0084] The refractive index of the visible light absorption layer 32 for light with a wavelength of 550 nm (visible light) is preferably 1.5 or higher and 4.0 or lower, more preferably 1.7 or higher and 3.5 or lower, and even more preferably 2.0 or higher and 2.5 or lower. Furthermore, the average refractive index of the visible light absorption layer 32 for light with wavelengths from 380 nm to 780 nm is preferably 1.5 or higher and 4.0 or lower, more preferably 1.7 or higher and 3.5 or lower, and even more preferably 2.0 or higher and 2.5 or lower. By ensuring that the refractive index and average refractive index of the visible light absorption layer 32 are within this range, the reflection of visible light can be suppressed, thereby making the far-infrared transmission member 20 inconspicuous. The refractive index for light with a wavelength of 550 nm can be determined, for example, by fitting an optical model using polarization information obtained from a spectral ellipsometer (manufactured by JAWoollam, M-2000) and spectral transmittance measured based on JIS R3106.

[0085] The extinction coefficient of the visible light absorbing layer 32 for light with a wavelength of 550 nm is preferably 0.04 or higher, more preferably 0.05 or higher, even more preferably 0.06 or higher, even more preferably 0.07 or higher, even more preferably 0.08 or higher, and even more preferably 0.10 or higher. Furthermore, the average extinction coefficient of the visible light absorbing layer 32 for light with wavelengths from 380 nm to 780 nm is preferably 0.04 or higher, more preferably 0.05 or higher, even more preferably 0.06 or higher, even more preferably 0.07 or higher, even more preferably 0.08 or higher, and even more preferably 0.10 or higher. By using extinction coefficients and average extinction coefficients within this range, the variance of visible light reflectance can be appropriately suppressed, and an appearance that ensures aesthetic design can be achieved. It should be noted that the average extinction coefficient refers to the average value of the extinction coefficients for each wavelength in this band (here, 380 nm to 780 nm). The extinction coefficient for light with a wavelength of 550 nm can be determined, for example, by fitting an optical model using polarization information obtained from a spectral ellipsometer and spectral transmittance measured based on JIS R3106.

[0086] The refractive index of the visible light absorption layer 32 for light with a wavelength of 10 μm (far-infrared) is preferably 1.5 or higher and 4.0 or lower, more preferably 1.7 or higher and 3.0 or lower, and even more preferably 2.0 or higher and 2.5 or lower. Furthermore, the average refractive index of the visible light absorption layer 32 for light with wavelengths of 8 μm to 12 μm is preferably 1.5 or higher and 4.0 or lower, more preferably 1.7 or higher and 3.0 or lower, and even more preferably 2.0 or higher and 2.5 or lower. By ensuring that the refractive index and average refractive index of the visible light absorption layer 32 for far-infrared light are within this range, the reflection of far-infrared light can be suppressed, thereby enabling appropriate transmission of far-infrared light. The refractive index for light with wavelengths of 8 μm to 12 μm can be determined, for example, by fitting an optical model using polarization information obtained from an infrared ellipsometer (manufactured by JA Woollam, IR-VASE-UT) and a spectroscopic transmission spectrum obtained from a Fourier transform infrared spectrometer (manufactured by Thermo Scientific, Nicolet iS10).

[0087] The visible light absorption layer 32 is capable of transmitting far-infrared radiation. The extinction coefficient of the visible light absorption layer 32 for light with a wavelength of 10 μm is preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0.02 or less. The average extinction coefficient of the visible light absorption layer 32 for light with wavelengths of 8 μm to 12 μm is preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0.02 or less. Within this range of extinction coefficient and average extinction coefficient, far-infrared radiation can be appropriately transmitted. The extinction coefficient for light with wavelengths of 8 μm to 12 μm can be determined, for example, by fitting an optical model using polarized light information obtained from an infrared ellipsometer and a spectroscopic transmission spectrum obtained from a Fourier transform infrared spectroscopy device.

[0088] Furthermore, 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. With a thickness d1 within this range, the reflection of far-infrared rays can be appropriately suppressed, while the reflection and scattering of visible light can also be appropriately suppressed. It should be noted that the thickness d1 can also be described as the length in the Z direction from the surface 32a of the visible light absorption layer 32 to the opposite surface 32b.

[0089] The material of the visible light absorbing layer 32 is arbitrary, but it is preferably a metal oxide as the main component. Here, "main component" can refer to a content of 50% by mass or more relative to the total visible light absorbing layer 32. Nickel oxide (NiO) is preferably used as the metal oxide for the visible light absorbing layer 32. x ), copper oxide (CuO) x ) and manganese oxide (MnO)x At least one of the following. The visible light absorbing layer 32 is preferably selected from NiO. x CuO x and MnO x At least one material from the group is used as the main component. It can be said that the visible light absorbing layer 32 is preferably made of NiO. x As a main component or selected from CuO x and MnO x This refers to any case where at least one material from the group is the main component. It should be noted that nickel oxide, copper oxide, and manganese oxide are known to have various compositions depending on the valence of nickel, copper, and manganese, and x can take any value within the range of 0.5 to 2. Furthermore, the valence may not be singular, but may be a mixture of two or more valences. In this embodiment, NiO is used as... x NiO is preferred as a substitute for CuO. x CuO is preferred as a substitute for MnO. x MnO is preferred. However, the material of the visible light absorbing layer 32 is not limited to this and can be arbitrary, such as diamond-like carbon.

[0090] (High refractive index layer)

[0091] The high refractive index layer 36 is a film that suppresses far-infrared radiation reflection by being stacked with the visible light absorbing layer 32 and the low refractive index layer 38. In this embodiment, the high refractive index layer 36 is stacked on the side closer to the substrate 30 than the visible light absorbing layer 32. Figure 5 In the example, the high refractive index layer 36 is disposed between the substrate 30 and the low refractive index layer 38. In the absence of a low refractive index layer 38, the high refractive index layer 36 is disposed between the substrate 30 and the visible light absorbing layer 32.

[0092] The high refractive index layer 36 is a film with a high refractive index for far-infrared light. The refractive index of the high refractive index layer 36 for light with a wavelength of 10 μm is higher than that of the visible light absorption layer 32. Preferably, the refractive index of the high refractive index layer 36 for light with a wavelength of 10 μm is 2.5 or higher and 4.5 or lower, more preferably 3.0 or higher and 4.5 or lower, and even more preferably 3.3 or higher and 4.3 or lower. Furthermore, the average refractive index of the high refractive index layer 36 for light with a wavelength of 8 μm to 12 μm is higher than that of the visible light absorption layer 32. Preferably, the average refractive index of the high refractive index layer 36 for light with a wavelength of 8 μm to 12 μm is 2.5 or higher and 4.5 or lower, more preferably 3.0 or higher and 4.5 or lower, and even more preferably 3.3 or higher and 4.3 or lower. With the refractive index and average refractive index of the high refractive index layer 36 within this range, it can function appropriately as a high refractive index film, thereby appropriately suppressing the reflection of far-infrared light.

[0093] The high refractive index layer 36 is capable of transmitting far-infrared radiation. The extinction coefficient of the high refractive index layer 36 for light with a wavelength of 10 μm is preferably 0.05 or less, more preferably 0.02 or less, and even more preferably 0.01 or less. The average extinction coefficient of the high refractive index layer 36 for light with wavelengths of 8 μm to 12 μm is preferably 0.05 or less, more preferably 0.02 or less, and even more preferably 0.01 or less. With the extinction coefficient and average extinction coefficient within this range, far-infrared radiation can be appropriately transmitted.

[0094] 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. With a thickness d2 within this range, the reflection of far-infrared rays can be appropriately suppressed. It should be noted that the thickness d2 can also be described as the length in the Z direction from the surface 36a of the high refractive index layer 36 to the opposite surface 36b.

[0095] The material of the high refractive index layer 36 can be arbitrary, but it is preferred to use at least one material selected from the group consisting of Si and Ge as the main component.

[0096] (Low-refractive-index layer)

[0097] The low-refractive-index layer 38 is a film that suppresses far-infrared radiation reflection by being stacked with the visible light absorbing layer 32 and the high-refractive-index layer 36. In this embodiment, the low-refractive-index layer 38 is stacked on the side closer to the substrate 30 than the visible light absorbing layer 32. Figure 5 In the example, the low refractive index layer 38 is disposed between the high refractive index layer 36 and the visible light absorbing layer 32. In the absence of a high refractive index layer 36, the low refractive index layer 38 is disposed between the substrate 30 and the visible light absorbing layer 32.

[0098] The low-refractive-index layer 38 is a film with a low refractive index for far-infrared light. The refractive index of the low-refractive-index layer 38 for light with a wavelength of 10 μm is lower than that of the visible light absorption layer 32. Preferably, the refractive index of the low-refractive-index layer 38 for light with a wavelength of 10 μm is 0.8 or higher and 2.0 or lower, more preferably 1.0 or higher and 1.7 or lower, and even more preferably 1.0 or higher and 1.5 or lower. Furthermore, the average refractive index of the low-refractive-index layer 38 for light with a wavelength of 8 μm to 12 μm is lower than that of the visible light absorption layer 32. Preferably, the average refractive index of the low-refractive-index layer 38 for light with a wavelength of 8 μm to 12 μm is 0.8 or higher and 2.0 or lower, more preferably 1.0 or higher and 1.7 or lower, and even more preferably 1.0 or higher and 1.5 or lower. With the refractive index and average refractive index of the low-refractive-index layer 38 within this range, it can function appropriately as a low-refractive-index film, thereby appropriately suppressing the reflection of far-infrared light.

[0099] The low-refractive-index layer 38 is capable of transmitting far-infrared radiation. The extinction coefficient of the low-refractive-index layer 38 for light with a wavelength of 10 μm is preferably 0.05 or less, more preferably 0.02 or less, and even more preferably 0.01 or less. The average extinction coefficient of the low-refractive-index layer 38 for light with wavelengths of 8 μm to 12 μm is preferably 0.05 or less, more preferably 0.02 or less, and even more preferably 0.01 or less. With the extinction coefficient and average extinction coefficient within this range, far-infrared radiation can be appropriately transmitted.

[0100] Furthermore, 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. With a thickness d3 within this range, the reflection of far-infrared rays can be appropriately suppressed. It should be noted that the thickness d3 can also be described as the length in the Z direction from the surface 38a of the low refractive index layer 38 to the opposite surface 38b.

[0101] The low refractive index layer 38 is preferably a film with oxide as its main component. More specifically, the low refractive index layer 38 is preferably MgO, which is an oxide, as its main component. The content of MgO in the low refractive index layer 38 is preferably 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. With the MgO content within this range, the low refractive index layer 38 can appropriately transmit far-infrared rays and, having a low refractive index for far-infrared rays, can appropriately suppress the reflection of far-infrared rays.

[0102] The low-refractive-index layer 38 may contain minor components, which are components other than the oxide (in this case, MgO) that is the main component. Preferred minor components are oxides that transmit infrared radiation, such as NiO. x CuO x , ZnO, ZrO2, Bi2O3, Y2O3.

[0103] (Characteristics of far-infrared transmission components)

[0104] As described above, the far-infrared transmission component 20 has a functional film 31 having at least one visible light absorption layer 32 formed on the surface of the substrate 30. By forming the functional film 31 with the visible light absorption layer 32 on the surface of the substrate 30, the far-infrared transmission component 20 appropriately transmits far-infrared rays while suppressing the reflectivity and reflectivity variance of visible light, thereby ensuring aesthetic design.

[0105] The transmittance of the far-infrared transmission member 20 for light with a wavelength of 10 μm is preferably 50% or more, more preferably 65% ​​or more, and even more preferably 70% or more. Furthermore, the average transmittance of the far-infrared transmission member 20 for light with wavelengths of 8 μm to 12 μm is preferably 50% or more, more preferably 65% ​​or more, and even more preferably 70% or more. By having transmittance and average transmittance within this range, it is possible to appropriately perform the function of a far-infrared transmission member.

[0106] The far-infrared transmission 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 average reflectance of the far-infrared transmission member 20 for light with wavelengths of 8 μm to 12 μm is preferably 15% or less, more preferably 10% or less, and even more preferably 5% or less. With reflectance and average reflectance within this range, it is possible to appropriately perform the function of a far-infrared transmission member. It should be noted that average reflectance refers to the average value of the reflectance of light at various wavelengths within this wavelength range (here, 8 μm to 12 μm). Reflectance can be measured, for example, using a Fourier transform infrared spectrometer (manufactured by Thermo Scientific, Nicolet iS10).

[0107] The visible light reflectance of the far-infrared transmission component 20, as specified in JIS R3106, is 25% or less, preferably 20% or less, and more preferably 18% or less. With a visible light reflectance within this range, the far-infrared transmission component 20 can suppress glare, thereby ensuring aesthetic design.

[0108] The variance D of the far-infrared transmission member 20 for light in the wavelength range of 360nm to 830nm in increments of 1nm is 30 or less, more preferably 25 or less, more preferably 20 or less, more preferably 15 or less, more preferably 10 or less, and more preferably 5 or less. In other words, the variance D refers to the variance of the far-infrared transmission member 20 for light whose wavelengths differ by 1nm each time in the wavelength range of 360nm to 830nm (i.e., light with wavelengths of 360nm, 361nm, 362nm, ... 830nm). That is, when the reflectivity of the far-infrared transmission member 20 for each light is set as x, the average reflectivity of the far-infrared transmission member 20 for each light whose wavelengths differ by 1nm each time in the wavelength range of 360nm to 830nm is set as μ, and the total number of light in the wavelength range of 360nm to 830nm in increments of 1nm is set as n, the variance D is expressed by the following formula (2). It should be noted that the reflectivity of light in the wavelength range of 360nm to 830nm in increments of 1nm can be determined according to JIS R3106.

[0109]

[0110] By reducing the difference in reflectivity of visible light of different wavelengths within the aforementioned range of variance D, interference colors of the far-infrared transmission component 20 can be suppressed, thereby ensuring the aesthetic design.

[0111] In addition, preferred options include Figure 3 The outer surface of the far-infrared transmission member 20 shown is formed flush (continuously) with the outer surface of the light-shielding area A2. In other words, it is installed so that the outer surface 20A of the far-infrared transmission member 20 is continuous with the surface 12A of the glass substrate 12. By making the surface 20A of the far-infrared transmission member 20 continuous with the surface 12A of the glass substrate 12 in this way, it is possible to suppress damage to the wiping effect of the wipers. In addition, it is possible to suppress the possibility of compromising the design of the vehicle V due to height differences, and the accumulation of sand and dust at height differences. Furthermore, the far-infrared transmission member 20 is preferably formed in accordance with the curved shape of the vehicle glass 1 to which it is applied. There are no particular limitations on the forming method of the far-infrared transmission member 20, and grinding or die forming can be selected depending on the curved shape and the component.

[0112] There are no particular limitations on the shape of the far-infrared transmission member 20, but a plate-like shape that matches the shape of the opening 19 is preferred. That is, for example, if the opening 19 is circular, the far-infrared transmission member 20 is preferably cylindrical. Furthermore, from an aesthetic design perspective, the surface shape of the far-infrared transmission member 20 on the outer side of the vehicle can be machined to match the curvature of the outer surface of the glass substrate 12. Moreover, for reasons such as balancing a wide-angle view of the far-infrared camera CA1 and improved mechanical properties, the far-infrared transmission member 20 can be made into a lens shape. When such a structure is made, even with a small area, far-infrared light can be effectively focused, which is therefore preferable. In this case, the number of lens-shaped far-infrared transmission members 20 is preferably 1 to 3, typically 2. Furthermore, the lens-shaped far-infrared transmission member 20 is particularly preferably pre-aligned and modularized, and integrated with the housing or bracket that adhesively bonds the far-infrared camera CA1 to the vehicle glass 1.

[0113] In the vehicle glass 1 of this embodiment, it is preferable to have a structure in which the area of ​​the opening 19 on the inner side of the vehicle is smaller than the area of ​​the opening 19 on the outer side of the vehicle, and the shape of the far-infrared transmission member 20 is also such that the area on the inner side of the vehicle is smaller than the area on the outer side of the vehicle. By making such a structure, the strength against impacts from the outside of the vehicle is improved. Furthermore, in the case where the vehicle glass 1 of this embodiment is a laminated glass having a glass substrate 12 (outer side of the vehicle) and a glass substrate 14 (inner side of the vehicle), 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 can be larger than the area of ​​the opening 14a of the glass substrate 14, and the far-infrared transmission member 20, which has the same size as the opening 12a of the glass substrate 12, is disposed in the opening 12a of the glass substrate 12.

[0114] In addition, such as Figure 3 As shown, in the far-infrared transmission member 20, the length D1 of the longest straight line connecting any two points on the outer surface of the vehicle is preferably 80 mm or less. More preferably, the length D1 is 70 mm or less, and even more preferably 65 mm or less. Furthermore, the length D1 is preferably 60 mm or more. Additionally, as... Figure 3 As shown, in the opening 19 of the far-infrared transmission region B, the length D2 of the longest straight line connecting any two points on the outer surface of the vehicle is preferably 80 mm or less. More preferably, the length D2 is 70 mm or less, and even more preferably 65 mm or less. Furthermore, the length D2 is preferably 60 mm or more. The length D2 can also be described as the length of the longest straight line connecting any two points on the outer periphery of the opening 19 on the outer surface (surface 12A) of the vehicle glass 1. With the length D1 of the far-infrared transmission member 20 and the length D2 of the opening 19 within this range, the reduction in the strength of the vehicle glass 1 can be suppressed, and the perspective distortion around the opening 19 can also be suppressed. It should be noted that when the shape of the outer surface of the far-infrared transmission member 20 is circular, the lengths D1 and D2 are lengths equivalent to the diameter of the outer surface of the vehicle. Furthermore, the lengths D1 and D2 here refer to the lengths when the vehicle glass 1 is mounted on the vehicle V. For example, if the glass is bent to form a shape that is mounted on the vehicle V, then the lengths D1 and D2 are the lengths in the state after the bending process. The same applies to the descriptions of dimensions and positions other than lengths D1 and D2 unless otherwise specified.

[0115] (Manufacturing method of infrared transmission component)

[0116] Next, the manufacturing method of the far-infrared transmission member 20 will be described. In manufacturing the far-infrared transmission member 20, a substrate 30 is prepared, and a functional film 31 is formed on the surface of the substrate 30. In this embodiment, the functional film 31 is formed on the surface of the substrate 30 by sputtering. Thus, the far-infrared transmission member 20 is manufactured. By using sputtering to form the functional film 31, the adhesion of the film can be improved. Furthermore, in this manufacturing method, the visible light absorbing layer 32 of the functional film 31 is NiO. x In this case, a functional film 31 is formed on the surface of the substrate 30 while heating at a temperature above 100°C and below 300°C. This adjusts the extinction coefficient of the visible light absorbing layer 32 in the functional film 31 to an appropriate value, while also improving the far-infrared transmittance, thereby achieving a proper balance between visible light absorption and far-infrared transmittance. However, the manufacturing method of the far-infrared transmittance member 20 is not limited to this. For example, the functional film 31 is not limited to being formed by sputtering; it can also be formed by vapor deposition. Since the functional film 31 is mainly composed of oxides, the formation method is not limited to vapor deposition, and various methods can be used, which is therefore preferred. In particular, forming the functional film 31 by sputtering improves productivity and film adhesion. Alternatively, annealing can be performed at a temperature above 100°C and below 300°C in an atmospheric atmosphere.

[0117] The visible light absorbing layer 32 of the functional film 31 is CuO. x In this case, after forming the functional film 31 on the surface of the substrate 30, it is preferable to perform annealing in an atmospheric atmosphere at a temperature of 100°C or higher and 600°C or lower for 0.5 hours to 2 hours. This adjusts the extinction coefficient of the visible light absorbing layer 32 in the functional film 31 to an appropriate value, while also improving the far-infrared transmittance, thereby achieving a proper balance between visible light absorption and far-infrared transmittance.

[0118] (Another example of this implementation)

[0119] In this embodiment, the far-infrared transmission member 20 has a structure in which only the functional film 31 is formed on the substrate 30, but it is not limited to this. Hereinafter, another example of the far-infrared transmission member 20 will be described.

[0120] Figure 6 This is a cross-sectional schematic diagram of another example of a far-infrared transmission component in this embodiment. Figure 6As shown, a protective film 34 can be formed on the surface 31a of the functional film 31 opposite to the substrate 30. The protective film 34 is formed on the outer surface of the far-infrared transmission member 20, i.e., the outermost surface exposed to the outside, and protects the functional film 31 from damage caused by wipers, dust, etc. 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 transmission member 20 on the outer side of the vehicle, and not on the inner side. However, the protective film 34 can 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 transmission member 20 on the inner side of the vehicle. It should be noted that... Figure 6 In the example, for ease of explanation, the functional membrane 31 is shown as a single layer, but the functional membrane 31 is not limited to a single layer and can also adopt any of the above-mentioned layer structures.

[0121] (Protective film)

[0122] The protective film 34 is preferably a film that is harder than the functional film 31. Specifically, the nanoindentation hardness of the protective film 34 is preferably higher than that of the functional film 31. By forming such a hard protective film 34 on the surface, the functional film 31 can be adequately protected from damage caused by wipers, dust, etc. The nanoindentation hardness can be measured, for example, using a nanoindentation instrument (manufactured by Toyo Technica Co., Ltd., iMicro nanoindentation instrument).

[0123] The refractive index of the protective film 34 for light with a wavelength of 550 nm (visible light) is preferably 2.5 or less, more preferably 1.5 or more and 2.5 or less, and even more preferably 1.7 or more and 2.4 or less. Furthermore, the average refractive index of the protective film 34 for light with wavelengths from 380 nm to 780 nm is preferably 2.5 or less, more preferably 1.5 or more and 2.5 or less, and even more preferably 1.7 or more and 2.4 or less. By ensuring that the refractive index and average refractive index of the protective film 34 for visible light are within this range, the reflection of visible light can be suppressed by combining it with the visible light absorption layer 32, thereby making the far-infrared transmission member 20 inconspicuous. It should be noted that the refractive index of the protective film 34 for light with a wavelength of 550 nm is preferably less than or equal to the refractive index of the visible light absorption layer 32 for light with a wavelength of 550 nm, and the average refractive index of the protective film 34 for light with wavelengths from 380 nm to 780 nm is preferably less than or equal to the average refractive index of the visible light absorption layer 32 for light with wavelengths from 380 nm to 780 nm.

[0124] The refractive index of the protective film 34 for light (far-infrared rays) with a wavelength of 10 μm is preferably 0.5 or higher and 3.5 or lower, more preferably 0.7 or higher and 2.5 or lower, and even more preferably 1.0 or higher and 2.5 or lower. Furthermore, the average refractive index of the protective film 34 for light with wavelengths of 8 μm to 12 μm is preferably 0.5 or higher and 3.5 or lower, more preferably 0.7 or higher and 2.5 or lower, and even more preferably 1.0 or higher and 2.5 or lower. By ensuring that the refractive index and average refractive index of the protective film 34 are within this range, the reflection of far-infrared rays can be suppressed, thereby appropriately transmitting far-infrared rays.

[0125] The protective film 34 is capable of transmitting far-infrared rays. The extinction coefficient of the protective film 34 for light with a wavelength of 10 μm is preferably 0.4 or less, more preferably 0.2 or less, and even more preferably 0.1 or less. The average extinction coefficient of the protective film 34 for light with wavelengths of 8 μm to 12 μm is preferably 0.4 or less, more preferably 0.2 or less, and even more preferably 0.1 or less. With the extinction coefficient and average extinction coefficient within this range, far-infrared rays can be appropriately transmitted.

[0126] 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. With a thickness d4 within this range, the reflection of far-infrared and visible light can be appropriately suppressed. It should be noted that the thickness d4 can also be described as the length in the Z direction from surface 34a of the protective film 34 to the opposite surface 34b.

[0127] The material of the protective film 34 is arbitrary, but preferably includes at least one material selected from the group consisting of ZrO2, Al2O3, TiO2, Si3N4, AlN, and diamond-like carbon. By using such a material, the protective film 34 can adequately protect the functional film 31.

[0128] To protect the functional membrane 31 from water, the protective membrane 34 preferably has water-resistant properties. That is, to maintain the appearance of the functional membrane 31 in the visible light region, the protective membrane 34 preferably protects the functional membrane 31 from water. The water-resistant properties of the protective membrane 34 vary depending on the material, crystal structure, and membrane thickness. Furthermore, from the viewpoint of water resistance, the protective membrane 34 is preferably an amorphous structure.

[0129] It should be noted that, like the functional film 31, the protective film 34 can also be formed by sputtering, but is not limited to this; for example, it can also be formed by vapor deposition.

[0130] Figure 7 This is a cross-sectional schematic diagram of another example of a far-infrared transmission component in this embodiment. Figure 7As shown, an adhesive film 40 can be formed between the functional film 31 and the substrate 30 in the far-infrared transmission member 20. Additionally, in Figure 7 In some examples, an image can also be formed on the outer surface. Figure 6 The same protective film as example 34. It should be noted that, in Figure 7 In the example, the functional membrane 31 is shown as a single layer, but the functional membrane 31 is not limited to a single layer and can also adopt any of the layer structures mentioned above.

[0131] (Adhesive film)

[0132] The adhesive film 40 is a film that enables the substrate 30 to adhere to the functional film 31; in other words, the adhesive film 40 is a film that enhances the adhesive strength between the substrate 30 and the functional film 31. The adhesive film 40 is disposed between the substrate 30 and the functional film 31.

[0133] The refractive index of the adhesive film 40 for light (far-infrared rays) with a wavelength of 10 μm is preferably 1.0 or higher and 4.3 or lower, more preferably 1.5 or higher and 4.3 or lower, and even more preferably 1.5 or higher and 3.8 or lower. Furthermore, the average refractive index of the adhesive film 40 for light with wavelengths of 8 μm to 12 μm is preferably 1.0 or higher and 4.3 or lower, more preferably 1.5 or higher and 4.3 or lower, and even more preferably 1.5 or higher and 3.8 or lower. By ensuring that the refractive index and average refractive index of the adhesive film 40 for far-infrared rays are within this range, the reflection of far-infrared rays can be suppressed, thereby appropriately transmitting far-infrared rays.

[0134] The adhesive film 40 is capable of transmitting far-infrared rays. The extinction coefficient of the adhesive film 40 for light with a wavelength of 10 μm is preferably 0.4 or less, more preferably 0.2 or less, and even more preferably 0.1 or less. The average extinction coefficient of the adhesive film 40 for light with wavelengths of 8 μm to 12 μm is preferably 0.4 or less, more preferably 0.2 or less, and even more preferably 0.1 or less. With the extinction coefficient and average extinction coefficient within this range, far-infrared rays can be appropriately transmitted.

[0135] 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. With a thickness d5 within this range, the reflection of far-infrared and visible light can be appropriately suppressed. It should be noted that the thickness d5 can also be described as the length in the Z direction from surface 40a to the opposite surface 40b of the adhesive film 40. Additionally, the thickness d5 of the adhesive film 40 is preferably less than the thickness d1 of the visible light absorbing layer 32, the thickness d2 of the high refractive index layer 36, and the thickness d3 of the low refractive index layer 38. By having the thickness d5 of the adhesive film 40 less than the thicknesses of these layers, the impact on optical performance can be reduced.

[0136] The material of the adhesion film 40 is arbitrary, but preferably contains materials selected from Si, Ge, MgO, and NiO. x CuO x The adhesive film 40 is made of at least one material selected from the group consisting of ZnS, Al2O3, ZrO2, SiO2, TiO2, ZnO, and Bi2O3. By using such a material, the substrate 30 can be suitably adhered to the functional film 31.

[0137] It should be noted that, like the functional film 31, the adhesion film 40 can also be formed by sputtering, but is not limited to this; for example, it can also be formed by vapor deposition.

[0138] (Effect)

[0139] As explained above, the far-infrared transmission member 20 of this embodiment includes a far-infrared transmission substrate 30 and a functional film 31 formed on the substrate 30. The far-infrared transmission member 20 has a variance D of reflectance in increments of 1 nm for light in the wavelength range of 360 nm to 830 nm of 300 nm or less, a visible light reflectance of 25% or less as specified in JIS R3106, and an average transmittance of 50% or more for light in the wavelength range of 8 μm to 12 μm. Here, it is required that the far-infrared transmission member appropriately transmits far-infrared rays. Furthermore, for far-infrared transmission members, for example, when installed in a manner exposed to the outside, it is sometimes required from an aesthetic design point of view that they are not easily noticeable. To meet this requirement, the far-infrared transmission member 20 of this embodiment has an average transmittance of 50% or more for light in the wavelength range of 8 μm to 12 μm, enabling it to appropriately transmit far-infrared rays. In addition, the far-infrared transmission member 20 has a visible light reflectance of 25% or less, which can suppress the intensity of reflected visible light. Furthermore, the far-infrared transmission member 20, with a variance D of 30 or less, reduces the difference in reflectivity for visible light of different wavelengths, thus suppressing the observation of interference colors. Therefore, the far-infrared transmission member 20 is not easily observed and is less likely to attract attention. In particular, the far-infrared transmission member 20 is sometimes disposed within a light-shielding area A2 formed of black ceramic or the like, which preferably improves its aesthetic compatibility with the light-shielding area A2. As described above, the far-infrared transmission member 20 has low visible light reflectivity and a small variance D, thus exhibiting high aesthetic compatibility with the light-shielding area A2 and ensuring a pleasing design.

[0140] The far-infrared transmission member 20 preferably has an average transmittance of 65% or more for light in the wavelength range of 8μm to 12μm. The far-infrared transmission member 20, with an average transmittance of 65% or more for light in the wavelength range of 8μm to 12μm, is capable of appropriately transmitting far-infrared rays.

[0141] The functional film 31 preferably has one or more visible light absorbing layers 32 with metal oxide as the main component. Since the main component of the visible light absorbing layer 32 is metal oxide, it can appropriately transmit far-infrared rays, while appropriately reducing visible light reflectivity and variance D, and appropriately ensuring the appearance design of the far-infrared transmission component 20.

[0142] Visible light absorbing layer 32 is preferably selected from NiO x CuO x and MnO x At least one material from the group is used as the main component. By setting the material of the visible light absorbing layer 32 in this way, it is possible to appropriately transmit far-infrared rays, while appropriately reducing the visible light reflectivity and variance D, and appropriately ensuring the appearance design of the far-infrared transmission component 20.

[0143] The functional film 31 preferably has one or more high refractive index layers 36, wherein the refractive index of the high refractive index layer 36 for light with a wavelength of 10 μm is higher than that of the visible light absorption layer 32. By providing a high refractive index layer 36 in addition to the visible light absorption layer 32, it can function appropriately as an anti-reflection film for far-infrared rays.

[0144] The functional film 31 preferably has one or more low-refractive-index layers 38, wherein the refractive index of the low-refractive-index layer 38 for light with a wavelength of 10 μm is lower than that of the visible light absorption layer 32. By providing a low-refractive-index layer 38 in addition to the visible light absorption layer 32, it can function appropriately as an anti-reflection film for far-infrared rays.

[0145] The functional film 31 preferably has one or more high-refractive-index layers 36 and one or more low-refractive-index layers 38. The high-refractive-index layer 36 has a higher refractive index for light with a wavelength of 10 μm than the visible light absorption layer 32, and the low-refractive-index layer 38 has a lower refractive index for light with a wavelength of 10 μm than the visible light absorption layer 32. The high-refractive-index layer 36 and the low-refractive-index layer 38 are alternately stacked between the substrate 30 and the visible light absorption layer 32. By alternately stacking the high-refractive-index layer 36 and the low-refractive-index layer 38 in this way, while providing the visible light absorption layer 32 on its outer side, reflection can be prevented over a wide wavelength range, while ensuring the aesthetic design of the far-infrared transmission component 20.

[0146] The high refractive index layer 36 is preferably composed of at least one material selected from the group consisting of Si and Ge. By setting the high refractive index layer 36 to such a material, it can function appropriately as an anti-reflective coating for far-infrared radiation.

[0147] The low-refractive-index layer 38 is preferably composed mainly of MgO. By setting the low-refractive-index layer 38 to such a material, it can function appropriately as an anti-reflective coating for far-infrared radiation.

[0148] The substrate 30 preferably comprises at least one material selected from the group consisting of Si, Ge, ZnS, and chalcogenide glasses. By setting the material of the substrate 30 in this way, far-infrared rays can be appropriately transmitted.

[0149] The far-infrared transmission member 20 preferably further includes a protective film 34 formed on its 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 transmission member 20 can appropriately protect the functional film 31 while ensuring the aesthetic design of the far-infrared transmission member 20.

[0150] The protective film 34 preferably comprises at least one material selected from the group consisting of ZrO2, Al2O3, TiO2, Si3N4, AlN, and diamond-like carbon. By setting the material of the protective film 34 in this way, the functional film 31 can be properly protected while ensuring the aesthetic design of the far-infrared transmission component 20.

[0151] The far-infrared transmission component 20 is preferably mounted on a vehicle. Because the far-infrared transmission component 20 can appropriately transmit far-infrared rays while ensuring aesthetic design, it can be appropriately mounted on a vehicle.

[0152] The far-infrared transmission component 20 can be mounted on the window component of a vehicle. Because the far-infrared transmission component 20 can appropriately transmit far-infrared rays while ensuring aesthetic design, it can be appropriately mounted on the window component of a vehicle.

[0153] The far-infrared transmission component 20 can be mounted on the exterior trim of the vehicle's pillars. Because the far-infrared transmission component 20 can appropriately transmit far-infrared rays while ensuring aesthetic design, it can be appropriately mounted on the exterior trim of the vehicle's pillars.

[0154] The far-infrared transmitting member 20 can be disposed within the light-shielding area A2 of the vehicle's exterior trim. Since the far-infrared transmitting member 20 can appropriately transmit far-infrared rays while ensuring aesthetic design, it can be appropriately mounted within the light-shielding area A2. Furthermore, the far-infrared transmitting member 20 is preferred due to its high compatibility with the appearance of the light-shielding area A2.

[0155] In the manufacturing method of the far-infrared transmission member 20 of this embodiment, the far-infrared transmission member 20 is manufactured by forming a functional film 31 on a far-infrared transmission substrate 30. The far-infrared transmission member 20 has a variance of reflectance in increments of 1 nm for light in the wavelength range of 360 nm to 830 nm of 30 or less, a visible light reflectance of 25% or less as specified in JIS R3106, and an average transmittance of 50% or more for light in the wavelength range of 8 μm to 12 μm. According to this manufacturing method, a far-infrared transmission member 20 that appropriately transmits far-infrared rays and ensures aesthetic design can be manufactured.

[0156] In the manufacturing method of the far-infrared transmission member 20 of this embodiment, the functional film 31 is preferably formed by sputtering. By forming the functional film 31 by sputtering, the adhesion of the film can be improved.

[0157] (Example)

[0158] The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Tables 1 to 3 show the examples. In Tables 1 to 3, the upper side of the membrane structure column represents the outer side of the vehicle, and the lower side represents the inner side of the vehicle.

[0159]

[0160]

[0161]

[0162] (Example 1)

[0163] In Example 1, the substrate itself was used as the far-infrared transmission component. 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 set to 2 mm ± 0.1 mm. It should be noted that the thickness was measured using a digital vernier caliper (manufactured by Mitutoyo Corporation, CD-15CX).

[0164] (Example 2)

[0165] In Example 2, a far-infrared transmission component was fabricated by forming functional films on both sides of a substrate using magnetron sputtering. In Example 2, the same Si substrate as in Example 1 was used, and the functional film was set as CuO serving as a visible light absorption layer. x Membrane. In Example 2, the thickness of the substrate was the same as in Example 1, and the thickness of the functional membrane was set to 1.13 μm.

[0166] In Example 2, firstly, a Cu target and a substrate, serving as film-forming materials, are positioned opposite each other in a magnetron sputtering apparatus. Next, the entire apparatus is evacuated to a vacuum. Then, when the pressure inside the apparatus reaches 5 × 10⁻⁴ Pa, a total of 20 SCCM (standard cubic centimeters / minute, 1 atmosphere (25°C)) of argon and oxygen is circulated. The evacuation rate is adjusted to maintain a pressure of 0.2 Pa inside the apparatus at this point. Then, a 200 W DC pulsed current (150 kHz) is applied to the target surface, and CuO is formed on the surface of the substrate while it rotates in front of the target. x membrane.

[0167] Then, the obtained CuO x The membrane was calcined in an atmospheric atmosphere at 400°C for 1 hour to obtain a far-infrared transmission component.

[0168] (Example 3)

[0169] In Example 3, a far-infrared transmission component was fabricated by forming functional films on both sides of a substrate using magnetron sputtering. In Example 3, the same Si substrate as in Example 1 was used, and the functional film was set as NiO serving as a visible light absorption layer. x Membrane. In Example 3, the thickness of the substrate was the same as in Example 1, and the thickness of the functional membrane was set to 1.14 μm.

[0170] In Example 3, firstly, NiO, as a film-forming material, is relatively positioned in a magnetron sputtering apparatus. x Target and substrate. Next, the entire apparatus is evacuated to a vacuum. Then, the pressure inside the apparatus reaches 5 × 10⁻⁶. -4 At a pressure of 0.5 Pa, a total of 80 SCCM of argon and oxygen was circulated. The exhaust rate was adjusted to maintain a pressure of 0.5 Pa within the apparatus at this point. Then, while heating the substrate to 150°C, a 400 W DC pulsed current (20 kHz) was applied to the target surface to form NiO on the substrate surface. x membrane.

[0171] (Example 4)

[0172] In Example 4, a black ceramic film is formed on the surface of the substrate that becomes the outer side of the vehicle, and a NiO film is formed on the surface of the substrate that becomes the inner side of the vehicle. x A film is formed to create a far-infrared transmitting component. In Example 4, the black ceramic film was formed using black ink (manufactured by Ferro, Black ink N9-104) and a screen printing machine. In Example 4, the thickness of the black ceramic film was set to 10 μm, and NiO was used... x The thickness of the film was set to 1.14 μm. In Example 4, the far-infrared transmission component was manufactured using the same method as in Example 3, except that...

[0173] (Example 5)

[0174] In Example 5, a far-infrared transmission component was fabricated by forming ZrO2 films on both sides of a substrate using magnetron sputtering. In Example 5, a 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 transmission component was fabricated using the same method as in Example 4, except for this.

[0175] (Example 6)

[0176] In Example 6, a far-infrared transmission component was fabricated by forming functional films on both sides of a substrate using magnetron sputtering. In Example 6, a Ge film as a high-refractive-index layer and a NiO film as a visible-light-absorbing layer were sequentially stacked from the substrate side. x Functional membrane. In Example 6, a Ge film was formed by sputtering using a Ge target. In Example 6, the thickness of the Ge film was set to 1.15 μm, and NiO was... x The thickness of the film was set to 1.14 μm. In Example 6, the far-infrared transmission component was manufactured using the same method as in Example 5, except that...

[0177] (Example 7)

[0178] In Example 7, a far-infrared transmission component was fabricated by forming functional films on both sides of a substrate using magnetron sputtering. In Example 7, a Ge film as a high-refractive-index layer, an MgO film as a low-refractive-index layer, and a NiO film as a visible light absorption layer were sequentially stacked from the substrate side. x Functional membrane. In Example 7, an MgO film was formed by sputtering using a Mg target. In Example 7, the thickness of the Ge film was set to 1.2 μm, the thickness of the MgO film was set to 0.3 μm, and the thickness of the NiO film was set to... x The thickness of the film was set to 0.9 μm. In Example 7, the far-infrared transmission component was manufactured using the same method as in Example 6, except that...

[0179] (Example 8)

[0180] In Example 8, a far-infrared transmission component was fabricated by forming functional films on both sides of a substrate using magnetron sputtering. In Example 8, five layers of MgO (low refractive index) and Ge (high refractive index) films were alternately stacked sequentially from the substrate side, followed by a NiO film as a visible light absorption layer. xThe functional film obtained by the film. In Example 8, starting from the substrate side, the thickness of the MgO film was sequentially set to 0.13 μm, the thickness of the Ge film was set to 0.34 μm, the thickness of the MgO film was set to 0.27 μm, the thickness of the Ge film was set to 1.45 μm, the thickness of the MgO film was set to 0.23 μm, and the thickness of the NiO film was set to... x The thickness of the film was set to 0.9 μm. In Example 8, the far-infrared transmission component was manufactured using the same method as in Example 7, except that...

[0181] (Example 9)

[0182] In Example 9, a far-infrared transmitting component was fabricated by forming a functional film and a protective film on both sides of a substrate using magnetron sputtering. In Example 9, the functional film was set as NiO, serving as a visible light absorbing layer. x The protective film is set as a ZrO2 layer. In Example 9, NiO is used. x The thickness of the membrane was set to 1 μm, and the thickness of the ZrO2 membrane was set to 0.3 μm. In Example 9, the far-infrared transmission component was manufactured using the same method as in Example 8, except that...

[0183] (Example 10)

[0184] In Example 10, a far-infrared transmission component was fabricated by forming a functional film and a protective film on both sides of a substrate using magnetron sputtering. In Example 10, the functional film was set as NiO, which served as a visible light absorption layer. x The protective film is set as an Al2O3 layer. In Example 10, NiO is used. x The thickness of the film was set to 1.14 μm, and the thickness of the Al2O3 film was set to 0.08 μm. In Example 10, the far-infrared transmission component was manufactured using the same method as in Example 9, except that...

[0185] (Example 11)

[0186] In Example 11, an adhesion film and a functional film were formed on both sides of a substrate by magnetron sputtering, thereby fabricating a far-infrared transmission component. In Example 11, the adhesion film was set as a Si film, and the functional film was set as NiO as a visible light absorption layer. x Film. In Example 11, the thickness of the Si film was set to 0.1 μm, and the NiO film was... x The thickness of the film was set to 1.14 μm. In Example 11, the far-infrared transmission component was manufactured using the same method as in Example 10, except that...

[0187] (Example 12)

[0188] In Example 12, a diamond-like carbon (DLC) film was formed as a visible light absorbing layer on the outer surface of the substrate, and a Ge film as a high-refractive-index layer and a ZnS film as a low-refractive-index layer were sequentially stacked on the inner surface of the substrate to form a functional film, thereby fabricating a far-infrared transmission component. In Example 12, the substrate thickness was the same as in Example 1. The DLC film was formed by plasma CVD, and the Ge and ZnS films were formed by vapor deposition. In Example 12, the thickness of the DLC film was set to 1 μm, 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 12, except for these other aspects, a far-infrared transmission component was manufactured using the same method as in Example 11.

[0189] (Example 13)

[0190] In Example 13, a Ge film and a ZnS film were sequentially laminated on both sides of a substrate to fabricate a far-infrared transmission component. 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 transmission component was fabricated using the same method as in Example 12, except for these other properties.

[0191] (Example 14)

[0192] In Example 14, the substrate itself is used as the far-infrared transmission component. That is, in Example 14, only the substrate is prepared, and no film is formed on the substrate. In Example 14, ZnS (MS grade) is used as the substrate. The thickness of the substrate is set to 2 mm ± 0.1 mm.

[0193] (Example 15)

[0194] In Example 15, a far-infrared transmission component was fabricated by forming functional films on both sides of a substrate using magnetron sputtering. In Example 15, the same ZnS substrate as in Example 14 was used, and a Ge film as a high-refractive-index layer and a NiO film as a visible light absorption layer were sequentially stacked from the substrate side. x Functional film. In Example 15, a Ge film was formed by sputtering using a Ge target. In Example 15, the thickness of the Ge film was set to 1.15 μm, and NiO was... x The thickness of the film was set to 1.14 μm. In Example 15, the far-infrared transmission component was manufactured using the same method as in Example 6, except that...

[0195] (Example 16)

[0196] In Example 16, the visible light reflectance and visible light reflectance variance of the optimal mode structure in Non-Patent Document 2 were calculated using optical simulation. The substrate was set to a 0.525 mm thick P-type Si substrate (Matsusaki Manufacturing Co., Ltd.) as described in Non-Patent Document 2, and NiO obtained using the method described in Non-Patent Document 2 was disposed on both sides of the substrate. x The membrane serves as a functional layer. NiO is used as the functional layer. x The film thickness was set to 1.2 μm, and NiO was obtained using the method described in Non-Patent Document 2. x The optical constants of the film were calculated using optical simulations to determine the visible light reflectance and its variance. The optical simulations were performed using simulation software (TFCalc, manufactured by Hulinks). The average far-infrared transmittance is cited from non-patent literature 2.

[0197] (Example 16)

[0198] In Example 16, the substrate was set to a P-type Si substrate (Matsusaki 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 disposed on both sides of the substrate. x The film serves as a functional layer. First, a Ni target and a substrate, serving as film-forming materials, are positioned relative to each other in a magnetron sputtering apparatus. Next, the entire apparatus is evacuated to a vacuum. Then, when the pressure inside the apparatus reaches 5 × 10⁻⁴ Pa, a total of 20 SCCM (standard cubic centimeters / minute, 1 atmosphere (25°C)) of argon and oxygen is circulated. The evacuation rate is adjusted to maintain a pressure of 3.5 mTorr within the apparatus at this point. Then, a high-frequency current of 400 W is applied to the target surface to form NiO on the surface of the substrate. x Membrane. Then, the obtained NiO... x The film was annealed at 600°C in an atmospheric atmosphere for 1 hour to produce the product. NiO was then used to anneal the film. x The film thickness was set to 1.2 μm.

[0199] It should be noted that in Examples 2, 3, 6, 7, 8, 9, 10, 11, 12, and 15, a visible light absorbing layer has an extinction coefficient of 0.04 or higher for light with a wavelength of 550 nm. In Example 16, NiO... x The film has an extinction coefficient of 0.02 for light with a wavelength of 550 nm, making it unsuitable as a visible light absorption layer. The extinction coefficient for light with a wavelength of 550 nm was determined by fitting an optical model using polarization information obtained from a spectral ellipsometer and spectral transmittance measured based on JIS R3106.

[0200] (evaluate)

[0201] The visible light and far-infrared transmission performance of samples 1 to 15 were evaluated. For visible light performance, the reflectance and variance of the visible light reflectance of the outer surface of the samples were measured. The visible light reflectance was measured using the method specified in JIS R3106. Furthermore, the variance of the reflectance of each light source in increments of 1 nm within the wavelength range of 360 nm to 830 nm, measured using the method specified in JIS R3106, was calculated as the variance of the visible light reflectance. A visible light reflectance of 15% or less was denoted as ◎, a visible light reflectance greater than 15% and less than or equal to 20% was denoted as 〇, a visible light reflectance greater than 20% and less than or equal to 25% was denoted as △, and a visible light reflectance greater than 25% was denoted as ×. △, 〇, and ◎ were set as acceptable. In addition, variances below 5 are represented by ◎, variances greater than 5 and less than or equal to 10 are represented by 〇, variances greater than 10 and less than or equal to 30 are represented by △, and variances greater than 30 are represented by ×. △, 〇 and ◎ are set as qualified.

[0202] In the evaluation of far-infrared transmission performance, the average transmittance of the sample was evaluated. Here, the average transmittance is the average transmittance of light at various wavelengths within the range of 8 μm to 12 μm. In this embodiment, a Fourier transform infrared spectrometer (manufactured by Thermo Scientific, trade name: Nicolet iS10) was used to measure the transmittance of light at various wavelengths within the range of 8 μm to 12 μm, and the average transmittance was calculated based on the measured transmittance. In the evaluation of far-infrared transmission performance, an average transmittance of 70% or higher is represented by ◎, an average transmittance greater than or equal to 65% but less than 70% is represented by 〇, an average transmittance greater than or equal to 50% but less than 65% is represented by △, and an average transmittance less than 50% is represented by ×. △, 〇, and ◎ are set as acceptable.

[0203] (Evaluation of Example 16)

[0204] In Example 16, the visible light reflectance and visible light reflectance variance of the optimal mode structure in Non-Patent Document 2 were calculated using optical simulation. Furthermore, NiO obtained using the method described in Non-Patent Document 2 was... x The optical constants of the film were calculated using optical simulations to determine the visible light reflectance and its variance. The optical simulations were performed using simulation software (TFCalc, manufactured by Hulinks). The average far-infrared transmittance is cited from non-patent literature 2.

[0205] (Evaluation Results)

[0206] The evaluation results for each sample are shown in Tables 1 to 3. As shown in Tables 1 to 3, it can be seen that in Examples 2, 3, 6, 7, 8, 9, 10, 11, 12, and 15, which are examples, all the visible light reflectance, variance, and far-infrared average transmittance are satisfied. On the other hand, it can be seen that in Examples 1, 4, 5, 13, and 14, which are comparative examples, at least one of the visible light reflectance, variance, and far-infrared average transmittance is not satisfied.

[0207] Figure 8 and Figure 9 A graph showing the evaluation results for each example. Figure 8 A graph showing the reflectance at each wavelength in the visible light band for Examples 5 and 13. Figure 8 For example, the result for line segment L5 is 5, and the result for line segment L13 is 13. Figure 8 As shown, in Examples 5 and 13, the difference (i.e., variance) of reflectivity at each wavelength increases. When the difference (i.e., variance) of reflectivity at each wavelength increases, iridescent optical interference colors are generated within the infrared transmission substrate surface due to the intensity difference of reflected light at each wavelength, thus becoming more prominent.

[0208] Figure 9 A graph showing the reflectance at each wavelength in the visible light band for Examples 1, 3, 4, 8, 10, 12, and 15. Figure 9 For example, the result for line segment L1 is 1; the result for line segment L3 is 3; the result for line segment L4 is 4; the result for line segment L8 is 8; the result for line segment L10 is 10; the result for line segment L12 is 12; and the result for line segment L15 is 15. Figure 9 As shown, it can be seen that in Example 1, Example 3, Example 4, Example 8, Example 12, and Example 15, Figure 9 The difference (i.e., variance) of reflectance at each wavelength decreases. When the difference (i.e., variance) of reflectance at each wavelength is less than 30, no iridescent optical interference colors are produced within the infrared transmission substrate surface, resulting in a blackish appearance with high affinity to the light-shielding area. Regarding Example 1, in addition to a large variance in reflectance for visible light, the visible light reflectance is as high as 25% or more, making it conspicuous due to its shimmering appearance. Regarding Example 4, the variance in reflectance for visible light is very small, and the visible light reflectance is also very low, but the far-infrared transmission performance deteriorates. Regarding Examples 3, 8, 12, and 15, since the variance in reflectance and the visible light reflectance are both sufficiently small, they result in a non-shimmering, blackish, and inconspicuous appearance.

[0209] The embodiments of the present invention have been described above, but the embodiments are not limited to the content of these embodiments. Furthermore, the above-described constituent elements include elements readily conceived by those skilled in the art, substantially the same elements, and elements of so-called equivalent scope. In addition, the above-described constituent elements can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the constituent elements can be made without departing from the spirit of the above-described embodiments.

[0210] Label Explanation

[0211] 1. Vehicle glass

[0212] 10, 12, 14 Glass substrate

[0213] 16 Intermediate Layers

[0214] 18. Light-shielding layer

[0215] 20 Far-infrared transmission components

[0216] 30 Substrate

[0217] 31 Functional Membranes

[0218] 32 Visible light absorption layer

Claims

1. A far-infrared transmitting component, the far-infrared transmitting component comprising: Substrate that transmits far-infrared rays, and A functional film formed on the substrate, wherein, The far-infrared transmission component The variance of reflectance for light in the wavelength range of 360nm to 830nm, in increments of 1nm, is less than 30. The visible light reflectance specified in JIS R3106 is 25% or less, and The average transmittance for light in the wavelength range of 8μm to 12μm is over 50%. The functional film is a multilayer film obtained by stacking a visible light absorbing layer with at least one of a high refractive index layer and a low refractive index layer, wherein the extinction coefficient of the visible light absorbing layer for light with a wavelength of 550 nm is greater than 0.

04. The visible light absorbing layer has an average refractive index of 1.5 or higher and 4.0 or lower for light with wavelengths of 380nm to 780nm, and an average extinction coefficient of 0.04 or higher for light with wavelengths of 380nm to 780nm.

2. The far-infrared transmission component as described in claim 1, wherein, The functional membrane has one or more visible light absorbing layers with metal oxides as the main component.

3. The far-infrared transmission component as described in claim 1, wherein, The visible light absorbing layer is made of NiO. x As a main component.

4. The far-infrared transmission component according to any one of claims 1 to 3, wherein, The functional film has one or more high refractive index layers, and the refractive index of the high refractive index layer for light with a wavelength of 10 μm is higher than that of the visible light absorption layer for light with a wavelength of 10 μm.

5. The far-infrared transmission component according to any one of claims 1 to 3, wherein, The functional film has one or more low-refractive-index layers, and the refractive index of the low-refractive-index layer for light with a wavelength of 10 μm is lower than the refractive index of the visible light absorption layer for light with a wavelength of 10 μm.

6. The far-infrared transmission component according to any one of claims 1 to 3, wherein, The functional film has one or more high-refractive-index layers and one or more low-refractive-index layers. The refractive index of the high-refractive-index layer for light with a wavelength of 10 μm is higher than that of the visible light absorption layer for light with a wavelength of 10 μm, and the refractive index of the low-refractive-index layer for light with a wavelength of 10 μm is lower than that of the visible light absorption layer for light with a wavelength of 10 μm. The high refractive index layer and the low refractive index layer are alternately stacked between the substrate and the visible light absorbing layer.

7. The far-infrared transmission component as described in claim 4, wherein, The high refractive index layer uses at least one material selected from the group consisting of Si and Ge as its main component.

8. The far-infrared transmission component as described in claim 5, wherein, The low-refractive-index layer uses MgO as its main component.

9. The far-infrared transmission component according to any one of claims 1 to 3, wherein, The far-infrared transmission component also includes a protective film formed on the outer surface of the far-infrared transmission component and having a refractive index of less than 2.5 for light with a wavelength of 550 nm.

10. The far-infrared transmission component as described in claim 9, wherein, The protective film comprises at least one material selected from the group consisting of ZrO2, Al2O3, TiO2, Si3N4, AlN, and diamond-like carbon.

11. The far-infrared transmission component according to any one of claims 1 to 3, wherein, The substrate comprises at least one material selected from the group consisting of Si, Ge, ZnS and chalcogenide glasses.

12. The far-infrared transmission component according to any one of claims 1 to 3, wherein, The far-infrared transmission component will be mounted on the vehicle.

13. The far-infrared transmission component as described in claim 12, wherein, The far-infrared transmission component will be positioned within the light-shielding area of ​​the vehicle's exterior trim.

14. A method for manufacturing a far-infrared transmission component, wherein, Far-infrared transmission components are manufactured by forming a functional film on a substrate that transmits far-infrared rays. The far-infrared transmission component The variance of reflectance for light in the wavelength range of 360nm to 830nm, in increments of 1nm, is less than 30. The visible light reflectance specified in JIS R3106 is 25% or less, and The average transmittance for light in the wavelength range of 8μm to 12μm is over 50%. The functional film is a multilayer film obtained by stacking a visible light absorbing layer with at least one of a high refractive index layer and a low refractive index layer, wherein the extinction coefficient of the visible light absorbing layer for light with a wavelength of 550 nm is greater than 0.

04. The visible light absorbing layer has an average refractive index of 1.5 or higher and 4.0 or lower for light with wavelengths of 380nm to 780nm, and an average extinction coefficient of 0.04 or higher for light with wavelengths of 380nm to 780nm.

Images