Vehicle glass

Abstract

The present invention prevents degradation of accuracy of detecting infrared light. A glass for a vehicle has a far infrared light transmitting region formed within a light shielding region, the far infrared light transmitting region having an opening, and a far infrared light transmitting member (20) disposed within the opening. The far infrared light transmitting member (20), when irradiated with far infrared light perpendicular to a vehicle exterior surface (20a), has a difference between an average transmittance of far infrared light with a wavelength of 8 μm to 13 μm at a first position (P1) and an average transmittance of far infrared light with a wavelength of 8 μm to 13 μm at a second position (P2) which is lower than the first position (P1) in a vertical direction when the glass for the vehicle is installed on the vehicle.

Description

Technical Field

[0001] The present invention relates to vehicle glass.

Background Art

[0002] In recent years, for the purpose of improving the safety of automobiles, various sensors may be attached. Examples of sensors attached to automobiles include cameras, LiDAR (Light Detecting and Ranging), millimeter-wave radars, and infrared sensors.

[0003] Infrared rays are classified into near-infrared (for example, wavelength 0.7 μm to 2 μm), mid-infrared (for example, wavelength 3 μm to 5 μm), and far-infrared (for example, wavelength 8 μm to 13 μm) depending on their wavelength bands. Examples of infrared sensors for detecting these infrared rays include touch sensors, near-infrared cameras and LiDAR for near-infrared, gas analysis and mid-infrared spectroscopic analysis (functional group analysis) for mid-infrared, and night vision and thermoviewers (hereinafter referred to as far-infrared cameras) for far-infrared.

[0004] Automobile window glass usually does not transmit far-infrared rays such as those with a wavelength of 8 μm to 13 μm. Therefore, far-infrared cameras have conventionally been installed outside the vehicle compartment, more specifically, in the front grille as in Patent Document 1 in many cases. However, when installing a far-infrared camera outside the vehicle compartment, the structure becomes more complicated and the cost becomes higher in order to ensure robustness, water resistance, dust resistance, etc. By installing the far-infrared camera inside the vehicle compartment and in the operating area of the wiper, the far-infrared camera is protected by the window glass, so that such problems can be solved. However, as described above, since the window glass has a problem of low far-infrared transmittance, usually, the far-infrared camera is not arranged inside the vehicle compartment.

[0005] In order to meet the above requirements, Patent Document 2 discloses a window member in which through holes are formed in a part of the window glass and infrared-transmissive members are filled in the through holes.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] Here, due to reasons such as the vehicle glass being installed inclined with respect to the vertical direction, the infrared transmittance at each position of the infrared transmitting member may become non-uniform. In this case, there is a risk that the detection accuracy by the infrared camera will decrease. Therefore, it is required to suppress the decrease in the detection accuracy of infrared rays.

[0008] The present invention has been made in view of the above problems, and an object thereof is to provide a vehicle glass capable of suppressing a decrease in the detection accuracy of infrared rays.

Means for Solving the Problems

[0009] In order to solve the above-described problems and achieve the object, a vehicle glass according to the present disclosure is a vehicle glass including a light-shielding region, and a far-infrared transmitting region in which an opening and a far-infrared transmitting member disposed in the opening are provided is formed in the light-shielding region. When the far-infrared transmitting member irradiates far-infrared rays in a direction perpendicular to the surface on the outside of the vehicle, the average transmittance of far-infrared rays having a wavelength of 8 μm to 13 μm at a first position is different from the average transmittance of far-infrared rays having a wavelength of 8 μm to 13 μm at a second position that is vertically below the first position when the vehicle glass is mounted on a vehicle.

Effects of the Invention

[0010] According to the present invention, a decrease in the detection accuracy of infrared rays can be suppressed.

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

[0012] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. Note that the present invention is not limited by this embodiment, and when there are a plurality of embodiments, those configured by combining each embodiment are also included. Also, numerical values include the range of rounding off.

[0013] (First Embodiment) (Vehicle) FIG. 1 is a schematic diagram showing a state in which the vehicle glass according to this embodiment is mounted on a vehicle. As shown in FIG. 1, the vehicle glass 1 according to this embodiment is mounted on a vehicle V. The vehicle glass 1 is a window member applied to the front glass of the vehicle V. That is, the vehicle glass 1 is used as the front window of the vehicle V, in other words, as a windshield. Inside the vehicle V (inside the vehicle), a far-infrared camera CA1 and a visible light camera CA2 are mounted. Note that the inside of the vehicle V (inside the vehicle) refers to, for example, the passenger compartment where the driver's driver's seat is provided.

[0014] The vehicle glass 1, the far-infrared camera CA1, and the visible light camera CA2 constitute a camera unit 100 according to this embodiment. The far-infrared camera CA1 is a camera that detects far-infrared rays, and by detecting far-infrared rays from the outside of the vehicle V, it captures a thermal image of the outside of the vehicle V. The visible light camera CA2 is a camera that detects visible light, and by detecting visible light from the outside of the vehicle V, it captures an image of the outside of the vehicle V. Note that the camera unit 100 may further include, for example, LiDAR or a millimeter-wave radar in addition to the far-infrared camera CA1 and the visible light camera CA2. Here, the far-infrared rays are, for example, electromagnetic waves in a wavelength band of 8 μm to 13 μm, and the visible light is, for example, electromagnetic waves in a wavelength band of 360 nm to 830 nm. Note that the far-infrared rays may be electromagnetic waves in a wavelength band of 8 μm to 12 μm. Also, the numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

[0015] (Vehicle Glass) Figure 2 is a schematic plan view of the vehicle glass according to the first embodiment. Figure 3 is a cross-sectional view taken along line A-A of Figure 2. Figure 4 is a cross-sectional view taken along the B-B cross-section of Figure 2. As shown in Figure 2, hereinafter, the upper edge of the vehicle glass 1 is referred to as the upper edge portion 1a, the lower edge as the lower edge portion 1b, one side edge as the side edge portion 1c, and the other side edge as the side edge portion 1d. The upper edge portion 1a is the edge portion located on the upper side in the vertical direction when the vehicle glass 1 is mounted on the vehicle V. The lower edge portion 1b is the edge portion located on the lower side in the vertical direction when the vehicle glass 1 is mounted on the vehicle V. The side edge portion 1c is the edge portion located on one side when the vehicle glass 1 is mounted on the vehicle V. The side edge portion 1d is the edge portion located on the other side when the vehicle glass 1 is mounted on the vehicle V.

[0016] Hereinafter, among the directions parallel to the surface of the vehicle glass 1, the direction from the upper edge portion 1a toward the lower edge portion 1b is defined as the Y direction, and the direction from the side edge portion 1c toward the side edge portion 1d is defined as the X direction. In the present embodiment, the X direction and the Y direction are orthogonal to each other. The direction orthogonal to the surface of the vehicle glass 1, that is, 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 toward the inside of the vehicle V when the vehicle glass 1 is mounted on the vehicle V. The X direction and the Y direction are along the surface of the vehicle glass 1. However, for example, when the surface of the vehicle glass 1 is a curved surface, they may be the directions tangent to the surface of the vehicle glass 1 at the center point O of the vehicle glass 1. The center point O is the center position of the vehicle glass 1 when viewed from the Z direction.

[0017] In the vehicle glass 1, a light-transmitting region A1 and a light-shielding region A2 are formed. The light-transmitting region A1 is a region occupying the central portion of the vehicle glass 1 when viewed from the Z direction. The light-transmitting region A1 is a region for securing the driver's field of view. The light-transmitting region A1 is a region that transmits visible light. The light-shielding region A2 is a region formed around the light-transmitting region A1 when viewed from the Z direction. The light-shielding region A2 is a region that shields visible light. In the light-shielding region A2, in the light-shielding region A2a which is the portion on the upper edge portion 1a side, a far-infrared transmitting region B and a visible light transmitting region C are formed.

[0018] The far-infrared transmission region B is a region that transmits far-infrared rays and is the region where the far-infrared camera CA1 is provided. That is, the far-infrared camera CA1 is provided at a position overlapping the far-infrared transmission region B when viewed from the optical axis direction of the far-infrared camera CA1. The visible light transmission region C is a region that transmits visible light and is the region where the visible light camera CA2 is provided. That is, the visible light camera CA2 is provided at a position overlapping the visible light transmission region C when viewed from the optical axis direction of the visible light camera CA2.

[0019] As described above, in the light-shielding region A2, since the far-infrared transmission region B and the visible light transmission region C are formed, the light-shielding region A2 shields far-infrared rays except in the region where the far-infrared transmission region B is formed, and shields visible light except in the region where the visible light transmission region C is formed. The far-infrared transmission region B and the visible light transmission region C are surrounded by a light-shielding region A2a. By providing the light-shielding region A2a around in this way, various sensors are protected from sunlight, which is preferable. Since the wiring of various sensors becomes invisible from outside the vehicle, it is also preferable from the viewpoint of design.

[0020] As shown in FIG. 3, the vehicle glass 1 includes a glass substrate 12 (first glass substrate), a glass substrate 14 (second glass substrate), an intermediate layer 16, and a light-shielding layer 18. In the vehicle glass 1, the glass substrate 12, the intermediate layer 16, the glass substrate 14, and the light-shielding layer 18 are laminated in this order in the Z direction. The glass substrate 12 and the glass substrate 14 are fixed (adhered) to each other via the intermediate layer 16.

[0021] As the glass substrates 12 and 14, for example, soda-lime glass, borosilicate glass, aluminosilicate glass, etc. can be used. The intermediate layer 16 is an adhesive layer that adheres the glass substrate 12 and the glass substrate 14. As the intermediate layer 16, for example, a polyvinyl butyral (hereinafter also referred to as PVB) modified material, an ethylene-vinyl acetate copolymer (EVA) based material, a urethane resin material, a vinyl chloride resin material, etc. can be used. More specifically, the glass substrate 12 includes one surface 12A and the other surface 12B, and the other surface 12B is in contact with one surface 16A of the intermediate layer 16 and is fixed (adhered) to the intermediate layer 16. The glass substrate 14 includes one surface 14A and the other surface 14B, and one surface 14A is in contact with the other surface 16B of the intermediate layer 16 and is fixed (adhered) to the intermediate layer 16. Thus, the vehicle glass 1 is a laminated glass in which the glass substrate 12 and the glass substrate 14 are laminated. However, the vehicle glass 1 is not limited to laminated glass, and for example, it may have a configuration including only one of the glass substrate 12 and the glass substrate 14. In this case, the intermediate layer 16 may not be provided either. Hereinafter, when the glass substrates 12 and 14 are not distinguished, they are described as the glass substrate 10.

[0022] The light-shielding layer 18 includes one surface 18A and the other surface 18B, and one surface 18A is in contact with and fixed to the other surface 14B of the glass substrate 14. The light-shielding layer 18 is a layer that shields visible light. As the light-shielding layer 18, for example, a ceramics light-shielding layer or a light-shielding film can be used. As the ceramics light-shielding layer, for example, a ceramics layer made of a conventionally known material such as a black ceramics layer can be used. As the light-shielding film, for example, a light-shielding polyethylene terephthalate (PET) film, a light-shielding polyethylene naphthalate (PEN) film, a light-shielding polymethyl methacrylate (PMMA) film, etc. can be used.

[0023] In this embodiment, the side where the light-shielding layer 18 is provided on the vehicle glass 1 is the inner side (inside the vehicle) of the vehicle V, and the side where the glass substrate 12 is provided is the outer side (outside the vehicle) of the vehicle V. However, it is not limited thereto, and the light-shielding layer 18 may be on the outer side of the vehicle V. When the laminated glass composed of the glass substrates 12 and 14 is used, the light-shielding layer 18 may be formed between the glass substrate 12 and the glass substrate 14.

[0024] (Light-shielding region) The light-shielding region A2 is formed by providing the light-shielding layer 18 on the glass substrate 10. That is, the light-shielding region A2 is a region where the glass substrate 10 includes the light-shielding layer 18. That is, the light-shielding region A2 is a region where the glass substrate 12, the intermediate layer 16, the glass substrate 14, and the light-shielding layer 18 are laminated. On the other hand, the light-transmitting region A1 is a region where the glass substrate 10 does not include the light-shielding layer 18. That is, the light-transmitting region A1 is a region where the glass substrate 12, the intermediate layer 16, and the glass substrate 14 are laminated and the light-shielding layer 18 is not laminated.

[0025] (Far-infrared transmission region) As shown in FIG. 3, the vehicle glass 1 has an opening 19 that penetrates from one surface (here, surface 12A) to the other surface (here, surface 14B) in the Z direction. An infrared transmitting member 20 is provided within the opening 19. The region where the opening 19 is formed and the infrared transmitting member 20 is provided is the infrared transmitting region B. That is, the infrared transmitting region B is the region where the opening 19 and the infrared transmitting member 20 disposed within the opening 19 are provided. Since the light shielding layer 18 does not transmit infrared rays, the light shielding layer 18 is not provided in the infrared transmitting region B. That is, in the 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, and the infrared transmitting member 20 is provided in the formed opening 19. The infrared transmitting member 20 will be described later. Note that the vehicle glass 1 can be said to include the glass substrate 10 and the infrared transmitting member 20 provided in the opening 19 of the glass substrate 10. The glass substrate 10 can also be called the part that constitutes the window glass among the vehicle glass 1. Here, for example, a configuration including the glass substrates 12, 14, the intermediate layer 16, and the light shielding layer 18 may be called the glass substrate 10. However, as described above, the glass substrate 10 may include only at least one of the glass substrate 12 and the glass substrate 14.

[0026] (Visible light region) As shown in FIG. 4, the visible light transmitting region C is, like the light transmitting region A1, in the Z direction, a region where the glass substrate 10 does not include the light shielding layer 18. That is, the visible light transmitting region C is a region where the glass substrate 12, the intermediate layer 16, and the glass substrate 14 are laminated and the light shielding layer 18 is not laminated.

[0027] As shown in FIG. 2, the visible light transmission region C is preferably provided in the vicinity of the far-infrared light transmission region B. Specifically, taking the center of the far-infrared light transmission region B viewed from the Z direction as the center point OB, and the center of the visible light transmission region C viewed from the Z direction as the center point OC. When the shortest distance between the far-infrared light transmission region B (opening 19) and the visible light transmission region C viewed from the Z direction is defined as the distance L, the distance L is preferably greater than 0 mm and equal to or less than 100 mm, and more preferably equal to or greater than 10 mm and equal to or less than 80 mm. By setting the visible light transmission region C at this position with respect to the far-infrared light transmission region B, it becomes possible to image images at a close position with the far-infrared camera CA1 and the visible light camera CA2, while suppressing the amount of perspective distortion in the visible light transmission region C, and appropriately imaging an image with the visible light camera CA2. By imaging images at a close position with the far-infrared camera CA1 and the visible light camera CA2, the load during arithmetic processing of data obtained from each camera is reduced, and the routing of power supplies and signal cables also becomes suitable.

[0028] As shown in FIG. 2, the visible light transmission region C and the far-infrared light transmission region B are preferably arranged side by side in the X direction. That is, the visible light transmission region C is not located on the Y-direction side of the far-infrared light transmission region B, and is preferably arranged side by side with the far-infrared light transmission region B in the X direction. By arranging the visible light transmission region C side by side with the far-infrared light transmission region B in the X direction, it becomes possible to minimize the parallax between the far-infrared camera and the visible light camera, improve the object recognition rate of the object, and arrange the visible light transmission region C in the vicinity of the upper edge portion 1a. Therefore, the driver's field of view in the light transmission region A1 can be appropriately ensured. Here, being arranged side by side in the X direction means being within a range of ±50 mm with respect to the Y direction.

[0029] (Infrared light transmission member) Hereinafter, the far-infrared ray transmitting member 20 provided in the far-infrared ray transmission region B will be specifically described. The far-infrared ray transmitting member 20 is a member that transmits far-infrared rays. As shown in FIG. 3, it is preferable that the outer surface of the far-infrared ray transmitting member 20 on the vehicle exterior side is formed flush (continuously) with the outer surface of the light-shielding region A2 on the vehicle exterior side. In other words, the outer surface 20a of the far-infrared ray transmitting member 20 on the vehicle exterior side is attached so as to be continuous with the surface 12A of the glass substrate 12. By making the surface 20A of the far-infrared ray transmitting member 20 continuous with the surface 12A of the glass substrate 12 in this way, it is possible to suppress the wiping effect of the wiper from being impaired. Further, it is possible to suppress the possibility that the design property of the vehicle V is impaired due to the presence of a step, or that dust or the like accumulates on the step. Furthermore, the far-infrared ray transmitting member 20 is preferably formed in accordance with the curved surface shape of the vehicle glass 1 to which it is applied. The molding method of the far-infrared ray transmitting member 20 is not particularly limited, but polishing or mold molding is selected according to the curved surface shape and the member.

[0030] The shape of the far-infrared ray transmitting member 20 is not particularly limited, but it is preferably a plate shape that matches the shape of the opening 19. That is, for example, when the opening 19 is circular, the far-infrared ray transmitting member 20 is preferably disk-shaped (cylindrical). Further, from the viewpoint of design, the surface shape of the far-infrared ray transmitting member 20 on the vehicle exterior side may be processed to match the curvature of the outer surface shape of the glass substrate 12. Furthermore, for reasons such as achieving both a wider viewing angle of the far-infrared camera CA1 and an improvement in mechanical characteristics, the far-infrared ray transmitting member 20 may be formed in a lens shape. With such a configuration, it is preferable because far-infrared light can be efficiently condensed even if the area of the far-infrared ray transmitting member 20 is small. In this case, the number of the lens-shaped far-infrared ray transmitting members 20 is preferably 1 to 3, and typically 2 is preferable. Furthermore, it is particularly preferable that the lens-shaped far-infrared ray transmitting member 20 is pre-aligned and modularized and integrated with a housing or a bracket for adhering the far-infrared camera CA1 to the vehicle glass 1.

[0031] In the vehicle glass 1 of the present embodiment, the area of the opening 19 on the inner side of the vehicle is configured to be smaller than the area of the opening 19 on the outer side of the vehicle, and it is preferable that the shape of the far-infrared transmitting member 20 is also adjusted so that the area on the inner side of the vehicle is smaller than the area on the outer side of the vehicle. By adopting such a configuration, the strength against impacts from the outside of the vehicle is improved. Further, when the vehicle glass 1 of the present embodiment is a laminated glass including 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 may be made larger than the area of the opening 14a of the glass substrate 14, and the far-infrared transmitting member 20 having a size corresponding to the size of the opening 12a of the glass substrate 12 may be disposed within the opening 12a of the glass substrate 12.

[0032] Also, as shown in FIG. 3, in the far-infrared transmission member 20, it is preferable that the length D1 of the longest straight line among the straight lines connecting any two points in the plane on the vehicle outer side is 80 mm or less. The length D1 is more preferably 70 mm or less, and still more preferably 65 mm or less. Also, the length D1 is preferably 40 mm or more. The length D1 is more preferably 50 mm or more, and still more preferably 60 mm or more. Further, as shown in FIG. 3, for the opening 19 of the far-infrared transmission region B, it is preferable that the length D2 of the longest straight line among the straight lines connecting any two points (here, any two points on the edge of the portion opening to the surface 12A side of the opening 19) in the plane on the vehicle outer side is 80 mm or less. The length D2 is more preferably 70 mm or less, and still more preferably 65 mm or less. Also, the length D2 is preferably 40 mm or more. The length D2 is more preferably 50 mm or more, and still more preferably 60 mm or more. The length D2 can also be said to be the length of the longest straight line among the straight lines connecting any two points on the outer periphery of the opening 19 on the vehicle outer side surface (surface 12A) of the vehicle glass 1. By setting the length D1 of the far-infrared transmission member 20 and the length D2 of the opening 19 within this range, a decrease in the strength of the vehicle glass 1 can be suppressed, and the amount of perspective distortion around the opening 19 can also be suppressed. Note that the lengths D1 and D2 are the lengths corresponding to the diameter of the outer surface on the vehicle outer side when the shape of the outer surface on the vehicle outer side of the far-infrared transmission member 20 is circular. Also, the lengths D1 and D2 here refer to the lengths in the state where the vehicle glass 1 is mounted on the vehicle V. For example, when the glass is bent and processed into a shape for mounting on the vehicle V, the lengths D1 and D2 are the lengths in the state after the bending process. The same applies to the description of dimensions and positions other than the lengths D1 and D2, unless otherwise specified.

[0033] Further, a frame member may be provided on the outer peripheral edge of the far-infrared transmission member 20, and the far-infrared transmission member 20 may be attached to the opening 19 via the frame member.

[0034] (Transmittance of the far-infrared transmission member) FIG. 5 is a schematic diagram showing an example of a state in which a vehicle glass is attached to a vehicle. Here, as shown in FIG. 5, the vehicle glass 1 is often attached to the vehicle V so as to be inclined with respect to the vertical direction. Therefore, assuming that the direction along the downward direction in the vertical direction is the direction YV, the direction Y of the vehicle glass 1 in the state of being attached to the vehicle V is inclined with respect to the direction YV, and the outer surface 20a of the far-infrared transmitting member 20 on the vehicle exterior side is also inclined with respect to the direction YV. Further, assuming that the horizontal direction and the direction from the front to the rear of the vehicle V is the direction ZV, the direction Z of the vehicle glass 1 in the state of being attached to the vehicle V is inclined with respect to the direction ZV, and the perpendicular AX orthogonal to the surface 20a of the far-infrared transmitting member 20 is also inclined with respect to the direction ZV. Furthermore, the perpendicular AX of the far-infrared transmitting member 20 is inclined with respect to the optical axis AXR of the far-infrared camera CA1.

[0035] When the vehicle glass 1 is mounted in such an inclined manner, the far-infrared ray La that passes through the upper portion of the far-infrared ray transmitting member 20 in the vertical direction and enters the far-infrared camera CA, and the far-infrared ray Lb that passes through the lower portion of the far-infrared ray transmitting member 20 in the vertical direction and enters the far-infrared camera CA will have different incident angles and optical path lengths to the far-infrared ray transmitting member 20. As a result, the intensity of the far-infrared rays transmitted through the upper and lower portions of the far-infrared ray transmitting member 20 in the vertical direction will be different. This may reduce the detection accuracy of the far-infrared rays of the far-infrared camera CA1. Specifically, for example, the incident angle of the far-infrared rays to the lower portion of the far-infrared ray transmitting member 20 in the vertical direction becomes shallow, or the optical path length of the far-infrared rays passing through the lower portion of the far-infrared ray transmitting member 20 in the vertical direction becomes long. Therefore, the intensity of the far-infrared rays transmitted through the lower portion of the far-infrared ray transmitting member 20 in the vertical direction decreases, and there is a risk that the detection accuracy in the lower field of view in the vertical direction of the far-infrared camera CA1 will decrease. Furthermore, since there is an inevitable transmission loss in the constituent material of the far-infrared ray transmitting member 20, the increase in the optical path length of the far-infrared rays passing through the lower portion of the far-infrared ray transmitting member 20 in the vertical direction increases the transmission loss of the far-infrared rays transmitted through the lower portion of the far-infrared ray transmitting member 20 in the vertical direction, and there is also a risk that the accuracy of the thermal image obtained in the lower field of view in the vertical direction of the far-infrared camera CA1 will decrease. In contrast, in the present embodiment, by making the transmittance of the far-infrared rays incident perpendicularly to the incident surface (surface 20a) of the far-infrared ray transmitting member 20 different between the upper and lower portions in the vertical direction, the decrease in the detection accuracy of the far-infrared rays of the far-infrared camera CA1 is suppressed. This will be specifically described below.

[0036] FIG. 6 is a schematic cross-sectional view of the far-infrared transmission member according to the first embodiment. Here, as shown in FIG. 6, when the far-infrared ray L1 is irradiated in a direction perpendicular to the surface 20a, which is the outer surface of the vehicle of the far-infrared transmission member 20, the average transmittance of the far-infrared ray L1 having a wavelength of 8 μm to 13 μm at the first position P1 of the far-infrared transmission member 20 is defined as the average transmittance TR1. That is, the average transmittance TR1 refers to the average transmittance of the far-infrared ray having a wavelength of 8 μm to 13 μm when the far-infrared ray having a wavelength of 8 μm to 13 μm traveling in a direction perpendicular to the surface 20a is irradiated to a location overlapping the first position P1 on the surface 20a of the far-infrared transmission member 20. Further, when the far-infrared ray L1 is irradiated in a direction perpendicular to the surface 20a of the far-infrared transmission member 20, the average transmittance of the far-infrared ray L1 having a wavelength of 8 μm to 13 μm at the second position P2 of the far-infrared transmission member 20 is defined as the average transmittance TR2. That is, the average transmittance TR2 refers to the average transmittance of the far-infrared ray having a wavelength of 8 μm to 13 μm when the far-infrared ray having a wavelength of 8 μm to 13 μm traveling in a direction perpendicular to the surface 20a is irradiated to a location overlapping the second position P2 on the surface 20a of the far-infrared transmission member 20. Here, the average transmittance refers to the average value of the transmittances of the light of each wavelength in the wavelength band (here, from 8 μm to 13 μm), and the transmittance here refers to the ratio of the intensity of the far-infrared ray L2 emitted from the surface 20b (the inner surface of the vehicle of the far-infrared transmission member 20) on the side opposite to the surface 20a to the intensity of the far-infrared ray L1 incident on the surface 20a. The transmittance can be measured, for example, using a Fourier transform infrared spectrometer (manufactured by Thermo Scientific, trade name: Nicolet iS10).

[0037] As shown in FIGS. 5 and 6, in the far-infrared transmission member 20, the average transmittance TR1 at the first position P1 is different from the average transmittance TR2 at the second position P2. By having the average transmittance TR1 and the average transmittance TR2 be different, a decrease in the detection accuracy of far-infrared rays can be suppressed. Here, the second position P2 refers to a position on the Y-direction side relative to the first position P1. Therefore, it can be said that when the vehicle glass 1 is mounted on the vehicle V, the second position P2 is a position vertically below the first position P1. Further, in the present embodiment, the first position P1 is a position on the side opposite to the Y direction from the central position of the far-infrared transmission member 20 in the Y direction. For example, it may be a position separated by a distance H1 in the Y direction from the end face 20S1 on the side opposite to the Y direction (the upper end face in the vertical direction when mounted on the vehicle) of the far-infrared transmission member 20. The distance H1 is, for example, 25% of the total length of the far-infrared transmission member 20 in the Y direction. Also, in the present embodiment, the second position P2 is a position on the Y-direction side from the central position of the far-infrared transmission member 20 in the Y direction. For example, it may be a position separated by a distance H2 in the direction opposite to the Y direction from the end face 20S2 on the Y-direction side (the lower end face in the vertical direction when mounted on the vehicle) of the far-infrared transmission member 20. The distance H2 is, for example, 10 % of the length. Note that the first position P1 and the second position P2 may be the same position in the X direction. In other words, when the vehicle glass 1 is mounted on the vehicle V, they may be the same position in the horizontal direction.

[0038] In this embodiment, it is preferable that the average transmittance TR2 at the second position P2 of the far-infrared transmission member 20 is higher than the average transmittance TR1 at the first position P1. By making the average transmittance TR2 higher than the average transmittance TR1, even when the vehicle glass 1 is inclined and installed, the intensity of the far-infrared rays transmitted through the first position P1 and incident on the far-infrared camera CA1 can be made closer to the intensity of the far-infrared rays transmitted through the second position P2 and incident on the far-infrared camera CA1, and a decrease in the detection accuracy of the far-infrared rays can be suppressed. For example, the average transmittance TR2 is preferably 102% or more and 140% or less, more preferably 105% or more and 135% or less, and even more preferably 110% or more and 130% or less with respect to the average transmittance TR1. By making the ratio of the average transmittances within this range, a decrease in the detection accuracy of the far-infrared rays can be appropriately suppressed.

[0039] Furthermore, in this embodiment, it is preferable that the average transmittance of the far-infrared rays with a wavelength of 8 μm to 13 μm when the far-infrared transmission member 20 is irradiated with the far-infrared rays L1 in a direction perpendicular to the surface 20a increases as it goes in the Y direction (as it goes vertically downward when mounted on the vehicle). Therefore, it can be said that it is preferable that the average transmittance of the far-infrared rays with a wavelength of 8 μm to 13 μm when the far-infrared transmission member 20 is irradiated with the far-infrared rays L1 in a direction perpendicular to the surface 20a increases as it goes from the first position P1 to the second position P2. For example, the average transmittance when irradiating the far-infrared rays with a wavelength of 8 μm to 13 μm that travel in a direction perpendicular to the surface 20a at a position between the first position P1 and the second position P2 in the Y direction is higher than the average transmittance TR1 at the first position P1 and lower than the average transmittance TR2 at the second position P2. By increasing the average transmittance in this way as it goes toward the second position P2, even when the vehicle glass 1 is inclined and installed, the intensity of the far-infrared rays transmitted through the far-infrared transmission member 20 and incident on the far-infrared camera CA1 can be made closer to being uniform, and a decrease in the detection accuracy of the far-infrared rays can be suppressed.

[0040] In the above description, as shown in FIG. 5, the reason is that the vehicle glass 1 is attached in an inclined manner in the vertical direction, and the case where the intensity of the far-infrared ray Lb transmitted through the lower portion (second position PA2) in the vertical direction of the far-infrared ray transmitting member 20 and incident on the far-infrared camera CA becomes low has been described. However, it is not limited to this, and due to various reasons, it is also conceivable that the intensity of the far-infrared ray incident on the far-infrared camera CA differs between the upper portion (first position PA1) and the lower portion (second position PA2) in the vertical direction of the far-infrared ray transmitting member 20. For example, a case where the transmittance of the lower portion in the vertical direction of the far-infrared ray transmitting member 20 is higher is also assumed. The far-infrared ray transmitting member 20 according to the present embodiment may vary the transmittance of the far-infrared ray perpendicularly incident on the incident surface (surface 20a) of the far-infrared ray transmitting member 20 between the upper portion (first position PA1) and the lower portion (second position PA2) in the vertical direction in accordance with such a case.

[0041] (Thickness of far-infrared ray transmitting member) As one mode in which the average transmittance of the far-infrared ray having a wavelength of 8 μm to 13 μm differs as it goes in the Y direction, the thickness DA1 at the first position P1 and the thickness DA2 at the second position P2 of the far-infrared ray transmitting member 20 may be different. The thickness DA1 refers to the length along the Z direction from the surface 20a to the surface 20b at the first position P1, and the thickness DA2 refers to the length along the Z direction from the surface 20a to the surface 20b at the second position P2. By making the thickness DA1 and the thickness DA2 different, the average transmittance TR1 and the average transmittance TR2 can be made different, and a decrease in the detection accuracy of the far-infrared ray can be suppressed.

[0042] When controlling the transmittance according to the thickness of the far-infrared transmission member 20, it is preferable that the thickness DA2 at the second position P2 is smaller than the thickness DA1 at the first position P1. By making the thickness DA2 smaller than the thickness DA1, the average transmittance TR2 can be made higher than the average transmittance TR1, thereby suppressing a decrease in the detection accuracy of far-infrared rays. For example, the thickness DA2 is preferably 60% or more and 98% or less, more preferably 65% or more and 95% or less, and still more preferably 70% or more and 90% or less with respect to the thickness DA1. By setting the ratio of the thicknesses within this range, a decrease in the detection accuracy of far-infrared rays can be appropriately suppressed.

[0043] Furthermore, in the present embodiment, it is preferable that the thickness of the far-infrared transmission member 20 decreases as it goes in the Y direction (as it goes downward in the vertical direction when mounted on a vehicle). Therefore, it can also be said that the thickness of the far-infrared transmission member 20 preferably decreases as it goes from the first position P1 to the second position P2. By making the thickness decrease as it goes toward the second position P2, the average transmittance can be increased as it goes toward the second position P2, thereby suppressing a decrease in the detection accuracy of far-infrared rays.

[0044] Also, for example, it is preferable that the thickness of the far-infrared transmission member 20 is set such that the optical path length from the surface 20a to the surface 20b of each far-infrared ray that enters each position of the surface 20a, exits from the surface 20b, and enters the far-infrared camera CA1 is uniform. In other words, it is preferable that the thickness of the far-infrared transmission member 20 is set such that the difference between the longest optical path length and the shortest optical path length among the optical path lengths from the surface 20a to the surface 20b of each far-infrared ray that enters the surface 20a, exits from the surface 20b, and enters the far-infrared camera CA1 is equal to or less than a predetermined value. Note that the optical path length is a value obtained by multiplying the refractive index of the medium by the distance, and when the far-infrared ray passes through a plurality of layers, it is the total value of the products of the refractive index and distance of each layer.

[0045] (Layer configuration of the far-infrared transmission member) Hereinafter, the layer structure of the far-infrared transmission member 20 will be specifically described. As shown in FIG. 6, the far-infrared transmission member 20 has a base material 30 and a functional film 32 formed on the base material 30. In the example of FIG. 6, the functional film 32 is formed on the surface 30b of the base material 30. The surface 30b is the surface that becomes the inside of the vehicle when mounted on the vehicle glass 1. In the example of FIG. 6, the surface 30a on the opposite side of the surface 30b of the base material 30 is the outer surface 20a of the far-infrared transmission member 20, and the inner surface 32b of the functional film 32 is the inner surface 20b of the far-infrared transmission member 20.

[0046] (Base material) The base material 30 is a member capable of transmitting far-infrared rays. The base material 30 preferably has an average internal transmittance of 50% or more, more preferably 60% or more, and even more preferably 70% or more with respect to light (far-infrared rays) having a wavelength of 8 μm to 13 μm. When the average internal transmittance of the base material 30 at 8 μm to 13 μm falls within this numerical range, far-infrared rays can be appropriately transmitted, and for example, the performance of the far-infrared camera CA1 can be fully exhibited. Here, the average internal transmittance is the average value of the internal transmittances with respect to the light of each wavelength in the wavelength band (here, from 8 μm to 12 μm).

[0047] The internal transmittance of the base material 30 is the transmittance excluding the surface reflection loss at the incident side and the exit side, which is well known in the art, and the measurement may be performed by a method commonly used. The measurement is performed, for example, as follows.

[0048] Prepare a pair of flat samples (the first sample and the second sample) made of the base material having the same composition but different thicknesses. Both surfaces of the flat sample are planes that are parallel to each other and optically polished. Let the external transmittance including the surface reflection loss of the first sample be T1, the external transmittance including the surface reflection loss of the second sample be T2, the thickness of the first sample be Td1 (mm), the thickness of the second sample be Td2 (mm), and assuming Td1 < Td2, the internal transmittance τ at the thickness Tdx (mm) can be calculated by the following formula (1).

[0049] τ = exp[-Tdx×(lnT1 - lnT2) / ΔTd] ···(1)

[0050] Note that the external transmittance of infrared rays can be measured, for example, by a Fourier transform infrared spectrometer (manufactured by Thermo Scientific, product name: Nicolet iS10).

[0051] The substrate 30 preferably has a refractive index of 1.5 or more and 4.0 or less, more preferably 2.0 or more and 4.0 or less, and even more preferably 2.2 or more and 3.5 or less with respect to light having a wavelength of 10 μm. When the refractive index of the substrate 30 is within this numerical range, far-infrared rays can be appropriately transmitted, and for example, the performance of the far-infrared camera CA1 can be fully exhibited. The refractive index can be determined by fitting an optical model using, for example, polarization information obtained by an infrared spectroscopic ellipsometer (manufactured by J.A. Woollam Co., Ltd., IR-VASE-UT) and a spectroscopic transmission spectrum obtained by a Fourier transform infrared spectrometer.

[0052] The thickness D0 of the substrate 30 is preferably 1.5 mm or more and 5 mm or less, more preferably 1.7 mm or more and 4 mm or less, and even more preferably 1.8 mm or more and 3 mm or less. When the thickness D0 is within this range, far-infrared rays can be appropriately transmitted while ensuring strength. Note that the thickness D0 can also be said to be the length in the Z direction from the surface 30a to the surface 30b of the substrate 30. In the example of FIG. 6, the substrate 30 is preferably in a flat plate shape and has a uniform thickness at each position in the Y direction. The thickness being uniform here is not limited to being exactly the same, and also includes deviations within the range of general tolerances. However, the substrate 30 may have different thicknesses at each position in the Y direction. The total thickness of the substrate 30 and the functional film 32, that is, the thickness of the far-infrared ray transmission member 20 (corresponding to the thickness DA1 in FIG. 6), is preferably 1.5 mm or more and 5.5 mm or less, more preferably 1.7 mm or more and 4.5 mm or less, and even more preferably 1.8 mm or more and 3 mm or less.

[0053] The material of the substrate 30 is not particularly limited, and examples thereof include Si, Ge, ZnS, and chalcogenide glass. 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 glass. By using such a material for the substrate 30, far-infrared rays can be appropriately transmitted. A preferable composition of the chalcogenide glass is in atomic percentage, Ge + Ga: 7% to 25%, Sb: 0% to 35%, Bi: 0% to 20%, Zn: 0% to 20%, Sn: 0% to 20%, Si: 0% to 20%, La: 0% to 20%, S + Se + Te: 55% to 80%, Ti: 0.005% to 0.3%, Li + Na + K + Cs: 0% to 20%, and a composition containing F + Cl + Br + I: 0% to 20%. And this glass preferably has a glass transition point (Tg) of 140°C to 550°C.

[0054] Note that as the material of the substrate 30, it is more preferable to use Si or ZnS.

[0055] (Functional film) The functional film 32 is formed on the substrate 30 and is a film for suppressing the reflection of far-infrared rays and adjusting the transmittance of far-infrared rays.

[0056] In the example of FIG. 6, the functional film 32 includes an antireflection film (AR film) 34 and a far-infrared absorption layer 36. The functional film 32 is laminated in the order of the antireflection film 34 and the far-infrared absorption layer 36 in a direction away from the base material 30. That is, in the example of FIG. 6, they are laminated in the order of the base material 30, the antireflection film 34, and the far-infrared absorption layer 36 toward the inside of the vehicle, and the surface 36b of the far-infrared absorption layer 36 is the surface 20b on the vehicle interior side of the far-infrared transmission member 20 (the surface 32b on the vehicle interior side of the functional film 32). However, the lamination order of the base material 30, the antireflection film 34, and the far-infrared absorption layer 36 is not limited to this and is arbitrary. For example, they may be laminated in the order of the base material 30, the far-infrared absorption layer 36, and the antireflection film 34 toward the inside of the vehicle. Further, in the configuration of FIG. 6, the antireflection film 34 is not an essential component, and the functional film 32 may include the far-infrared absorption layer 36 without including the antireflection film 34.

[0057] (Antireflection film) The antireflection film 34 is a film that suppresses the reflection of far-infrared rays. In the example of FIG. 6, it is preferable that the thickness of the antireflection film 34 is uniform at each position in the Y direction. However, Anti-reflection film 34 the thickness may be different at each position in the Y direction.

[0058] In the example of FIG. 6, the antireflection film 34 includes a high refractive index layer 34A and a low refractive index layer 34B. In the example of FIG. 6, the high refractive index layer 34A and the low refractive index layer 34B are alternately laminated between the base material 30 and the far-infrared absorption layer 36. In the example of FIG. 6, the antireflection film 34 is laminated on the base material 30 in the order of the high refractive index layer 34A and the low refractive index layer 34B in a direction away from the base material 30. However, among the antireflection film 34, the layer formed closest to the base material 30 is not limited to the high refractive index layer 34A, and may be, for example, the low refractive index layer 34B. For example, they may be laminated in the order of the low refractive index layer 34B and the high refractive index layer 34A in a direction away from the base material 30.

[0059] Also, in the example of FIG. 6, the antireflection film 34 has a structure in which a high refractive index layer 34A and a low refractive index layer 34B are laminated one by one, but it is not limited thereto, and at least one of the high refractive index layer 34A and the low refractive index layer 34B may be laminated in multiple layers. For example, the antireflection film 34 may have a plurality of high refractive index layers 34A and low refractive index layers 34B laminated alternately in a direction away from the substrate 30 from the substrate 30. That is, the antireflection film 34 may be laminated in the order of the substrate 30, the high refractive index layer 34A, the low refractive index layer 34B, the high refractive index layer 34A,... the low refractive index layer 34B. Further, the antireflection film 34 may have a low refractive index layer 34B and a high refractive index layer 34A laminated alternately in a direction away from the substrate 30 from the substrate 30. That is, it may be laminated in the order of the substrate 30, the low refractive index layer 34B, the high refractive index layer 34A,... the low refractive index layer 34B.

[0060] Thus, the antireflection film 34 has a configuration including a high refractive index layer 34A and a low refractive index layer 34B, but is not limited thereto, and may be a film having any configuration that suppresses reflection of far-infrared rays.

[0061] (High refractive index layer) The high refractive index layer 34A is a film that is laminated with the low refractive index layer 34B to suppress reflection of far-infrared rays. The high refractive index layer 34A is a film having a high refractive index with respect to far-infrared rays, and the refractive index with respect to light having a wavelength of 10 μm is preferably 2.5 or more and 4.5 or less, more preferably 3.0 or more and 4.5 or less, and still more preferably 3.3 or more and 4.3 or less. Further, the high refractive index layer 34A preferably has an average refractive index with respect to light having a wavelength of 8 μm to 13 μm of 2.5 or more and 4.5 or less, more preferably 3.0 or more and 4.5 or less, and still more preferably 3.3 or more and 4.3 or less. By the refractive index and average refractive index of the high refractive index layer 34A falling within this numerical range, it can function appropriately as a high refractive index layer and can appropriately suppress reflection of far-infrared rays.

[0062] The high refractive index layer 34A is capable of transmitting far-infrared rays. The high refractive index layer 34A preferably has an average attenuation coefficient for light with a wavelength of 8 μm to 13 μm of 0.05 or less, more preferably 0.02 or less, and still more preferably 0.01 or less. By having the attenuation coefficient and the average attenuation coefficient within this range, far-infrared rays can be appropriately transmitted. The average attenuation coefficient is the average value of the attenuation coefficients of light at each wavelength in the wavelength band (here, from 8 μm to 13 μm). The attenuation coefficient can be determined, for example, by performing fitting of an optical model using polarization information obtained by a spectroscopic ellipsometer and spectroscopic transmittance measured based on JIS R3106.

[0063] Also, the thickness of the high refractive index layer 34A 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 still more preferably 0.3 μm or more and 1.2 μm or less. By having the thickness within this range, reflection of far-infrared rays can be appropriately suppressed.

[0064] The material of the high refractive index layer 34A can be arbitrary, and examples include those mainly composed of at least one material selected from the group of Si and Ge, diamond-like carbon (DLC), ZnSe, As2S3, As2Se3, and the like.

[0065] (Low refractive index layer) The low refractive index layer 34B is a film laminated with the high refractive index layer 34A to suppress reflection of far-infrared rays. The low refractive index layer 34B is a film with a low refractive index for far-infrared rays, and preferably has a refractive index for light with a wavelength of 10 μm of 0.8 or more and 2.0 or less, more preferably 1.0 or more and 1.7 or less, and still more preferably 1.0 or more and 1.5 or less. By having the refractive index of the low refractive index layer 34B within this numerical range, it can function appropriately as a low refractive index layer and can appropriately suppress reflection of far-infrared rays.

[0066] The low refractive index layer 34B can transmit far-infrared rays. The low refractive index layer 34B preferably has an average attenuation coefficient for light with a wavelength of 8 μm to 13 μm of 0.05 or less, more preferably 0.02 or less, and even more preferably 0.01 or less. By having the attenuation coefficient and the average attenuation coefficient within this range, far-infrared rays can be appropriately transmitted.

[0067] Also, the thickness of the low refractive index layer 34B 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. By having the thickness within this range, reflection of far-infrared rays can be appropriately suppressed.

[0068] The low refractive index layer 34B can be made of any material, such as ZnS, metal oxides (e.g., SiO x , Al2O3, NiO x , CuO x , ZnO, ZrO2, Bi2O3, Y2O3, CeO2, HfO2, MgO, TiO x , etc.), metal fluorides (e.g., MgF2, CaF2, SrF2, BaF2, PbF2, LaF3, YF3, etc.), and the like.

[0069] (Far-infrared absorption layer) The far-infrared absorption layer 36 is a layer that absorbs far-infrared rays. The far-infrared absorption layer 36 absorbs a part of the incident far-infrared rays and transmits the other part. The far-infrared absorption layer 36 preferably has an average attenuation coefficient for light with a wavelength of 8 μm to 13 μm of 0.002 or more and 1.0 or less, more preferably 0.01 or more and 0.5 or less, and even more preferably 0.05 or more and 0.2 or less. By having the average attenuation coefficient within this range, while appropriately transmitting far-infrared rays, the far-infrared transmittance can be appropriately controlled according to the film thickness of the transmittance adjustment layer.

[0070] The material of the far-infrared absorption layer 36 can be arbitrary, for example, diamond-like carbon (DLC), SiO x , Al2O3, NiO x , CuO x, ZnO, ZrO2, Bi2O3, Y2O3, CeO2, HfO2, MgO, TiO x , TiN, AlN, Si3N4, etc. can be mentioned.

[0071] It is preferable that the thickness DB1 at the first position P1 and the thickness DB2 at the second position P2 of the far-infrared absorption layer 36 are different. The thickness DB1 refers to the length along the Z direction from one surface 36a to the other surface 36b of the far-infrared absorption layer 36 at the first position P1, and the thickness DB2 refers to the length along the Z direction from the surface 36a to the surface 36b at the second position P2. By making the thickness DB1 and the thickness DB2 different, the average transmittance TR1 and the average transmittance TR2 can be made different, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0072] It is preferable that the thickness DB2 at the second position P2 of the far-infrared absorption layer 36 is smaller than the thickness DB1 at the first position P1. By making the thickness DB2 smaller than the thickness DB1, the average transmittance TR2 can be made higher than the average transmittance TR1, and a decrease in the detection accuracy of far-infrared rays can be suppressed. For example, the thickness DB2 is preferably 0% or more and 98% or less, more preferably 5% or more and 90% or less, and even more preferably 10% or more and 85% or less with respect to the thickness DB1. By making the ratio of the thicknesses within this range, a decrease in the detection accuracy of far-infrared rays can be appropriately suppressed.

[0073] Furthermore, in this embodiment, it is preferable that the thickness of the far-infrared absorption layer 36 decreases as it goes in the Y direction (as it goes vertically downward when mounted on a vehicle). Therefore, it can be said that the thickness of the far-infrared absorption layer 36 preferably decreases as it goes from the first position P1 to the second position P2. By making the thickness decrease as it goes toward the second position P2, the average transmittance can be increased as it goes toward the second position P2, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0074] In addition, the far-infrared absorption layer 36 preferably has a thickness at the thinnest part of 5 nm or more and 1000 nm or less, preferably 10 nm or more and 500 nm or less, and preferably 20 nm or more and 300 nm or less. By having the thickness at the thinnest part within this range, the far-infrared rays can be appropriately absorbed, and a decrease in the detection accuracy of the far-infrared rays can be suppressed.

[0075] The far-infrared ray transmitting member 20 according to the first embodiment has the above-described configuration. The far-infrared ray transmitting member 20 according to the first embodiment reduces the thickness of the far-infrared absorption layer 36 as it goes in the Y direction, thereby making the transmittance of the far-infrared rays incident on the far-infrared camera CA1 through the far-infrared ray transmitting member 20 closer to uniform and suppressing a decrease in the detection accuracy of the far-infrared rays.

[0076] (Another example) FIG. 7 is a schematic cross-sectional view of a far-infrared ray transmitting member according to another example of the first embodiment. In the example of FIG. 6, the functional film 32 was formed on the vehicle interior side of the base material 30, but it is not limited thereto. As shown in FIG. 7, the functional film 32 may be formed on the vehicle Outside side. In this case, as shown in FIG. 7, the far-infrared ray transmitting member 20 is laminated in the order of the far-infrared absorption layer 36, the antireflection film 34, and the base material 30 toward the vehicle interior side. The surface 36a of the far-infrared absorption layer 36 becomes the outer surface 20a of the far-infrared ray transmitting member 20 on the vehicle exterior side, and the surface 30b of the base material 30 becomes the inner surface 20b of the far-infrared ray transmitting member 20 on the vehicle interior side. However, the lamination order of the base material 30, the antireflection film 34, and the far-infrared absorption layer 36 is not limited to this and is arbitrary. For example, it may be laminated in the order of the antireflection film 34, the far-infrared absorption layer 36, and the base material 30 toward the vehicle interior side. Also, in the configuration of FIG. 7, the antireflection film 34 is not an essential component, and the functional film 32 may not include the antireflection film 34 and may include the far-infrared absorption layer 36.

[0077] In addition, the functional film 32 For example For example, the functional film 32 of FIG. 7 may be further formed on the far-infrared ray transmitting member 20 of FIG. 6. That is, the functional film 32 may be provided on at least one of the vehicle interior side and the vehicle exterior side of the base material 30.

[0078] FIG. 8 is a schematic cross-sectional view of a far-infrared transmission member according to another example of the first embodiment. In the above description, the far-infrared transmission member 20 has a structure in which a base material 30, an antireflection film 34, and a far-infrared absorption layer 36 are laminated, but other layers may also be laminated. For example, in the example of FIG. 8, a visible light absorption layer 38 is formed on the far-infrared transmission member 20 as another layer. The visible light absorption layer 38 is preferably formed on the outer side of the vehicle than the base material 30 and the functional film 32 as shown in FIG. 8, but the position where the visible light absorption layer 38 is provided may be arbitrary.

[0079] The visible light absorption layer 38 is a layer that absorbs visible light. The visible light absorption layer 38 preferably has a refractive index with respect to light (visible light) having a wavelength of 550 nm of 1.5 or more and 4.0 or less, more preferably 1.7 or more and 3.5 or less, and even more preferably 2.0 or more and 2.5 or less. Further, the visible light absorption layer 38 preferably has an average refractive index with respect to light having a wavelength of 380 nm to 780 nm of 1.5 or more and 4.0 or less, more preferably 1.7 or more and 3.5 or less, and even more preferably 2.0 or more and 2.5 or less. By the refractive index and average refractive index of the visible light absorption layer 38 with respect to visible light falling within this numerical range, it is possible to suppress the reflection of visible light and make the far-infrared transmission member 20 less conspicuous.

[0080] The visible light absorption layer 38 preferably has an attenuation coefficient of light having a wavelength of 550 nm of 0.04 or more, more preferably 0.05 or more, even more preferably 0.06 or more, even more preferably 0.07 or more, even more preferably 0.08 or more, and even more preferably 0.10 or more. Further, the visible light absorption layer 38 preferably has an average attenuation coefficient with respect to light having a wavelength of 380 nm to 780 nm of 0.04 or more, more preferably 0.05 or more, even more preferably 0.06 or more, even more preferably 0.07 or more, even more preferably 0.08 or more, and even more preferably 0.10 or more. By the attenuation coefficient and average attenuation coefficient falling within this range, it is possible to appropriately suppress the reflectance dispersion of visible light and obtain an appearance with ensured design quality.

[0081] The visible light absorption layer 38 preferably has a refractive index with respect to light having a wavelength of 10 μm (far-infrared light) of 1.5 or more and 4.0 or less, more preferably 1.7 or more and 3.0 or less, and still more preferably 2.0 or more and 2.5 or less. Further, the visible light absorption layer 38 preferably has an average refractive index with respect to light having a wavelength of 8 μm to 13 μm of 1.5 or more and 4.0 or less, more preferably 1.7 or more and 3.0 or less, and still more preferably 2.0 or more and 2.5 or less. By setting the refractive index and the average refractive index of the visible light absorption layer 38 with respect to far-infrared light within this numerical range, reflection of far-infrared light can be suppressed and far-infrared light can be appropriately transmitted.

[0082] The visible light absorption layer 38 can transmit far-infrared light. The visible light absorption layer 38 preferably has an average attenuation coefficient with respect to light having a wavelength of 8 μm to 13 μm of 0.1 or less, more preferably 0.05 or less, and still more preferably 0.02 or less. By setting the attenuation coefficient and the average attenuation coefficient within this range, far-infrared light can be appropriately transmitted.

[0083] Further, the thickness of the visible light absorption layer 38 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 still more preferably 0.8 μm or more and 1.4 μm or less. By setting the thickness within this range, reflection and dispersion of visible light can be appropriately suppressed while appropriately suppressing reflection of far-infrared light.

[0084] The material of the visible light absorption layer 38 is arbitrary, but it is preferably mainly composed of a metal oxide. Here, the main component may refer to a content of 50% by mass or more with respect to the entire visible light absorption layer 38. As the metal oxide used for the visible light absorption layer 38, nickel oxide (NiO x ), copper oxide (CuO x ), and manganese oxide (MnO x ) are preferably at least any one of them. The visible light absorption layer 38 is NiO x , CuO x , and MnO xIt is preferable to use at least one material selected from the group as the main component. The visible light absorption layer 38 is mainly composed of NiOx, or CuO x and MnO x It can be said that either of them is preferably mainly composed of at least one material selected from the group. Note that nickel oxide, copper oxide, and manganese oxide are known to have multiple compositions depending on the valences of nickel, copper, and manganese, and x can take any value from 0.5 to 2. Also, the valence may not be single, and two or more valences may be mixed. In this embodiment, as NiO x it is preferable to use NiO, and as CuO x it is preferable to use CuO, and as MnO x it is preferable to use MnO. However, the material of the visible light absorption layer 38 is not limited to these and can be arbitrary. For example, it may be diamond-like carbon.

[0085] In the above description, the visible light absorption layer 38 has been described as a layer other than the base material 30, the antireflection film 34, and the far-infrared absorption layer 36. However, a layer different from the visible light absorption layer 38 may be laminated, or another layer may be laminated in addition to the visible light absorption layer 38. Examples of another layer include a protective film formed on the outermost surface of the far-infrared transmission member 20 facing the outside of the vehicle. As the protective film, for example, it preferably contains at least one material selected from the group of ZrO2, Al2O3, TiO2, Si3N 4、 AlN, and diamond-like carbon. By forming the protective film, the far-infrared transmission member 20 can be appropriately protected.

[0086] (Effect) As described above, the vehicle glass 1 according to the first embodiment includes a light-shielding region A2, and a far-infrared transmission region B is formed in the light-shielding region A2, in which an opening 19 and a far-infrared transmission member 20 disposed in the opening 19 are provided. When the far-infrared transmission member 20 is irradiated with far-infrared rays in a direction perpendicular to the outer surface 20a of the vehicle exterior, the average transmittance TR1 of far-infrared rays with a wavelength of 8 μm to 13 μm at the first position P1 is different from the average transmittance TR2 of far-infrared rays with a wavelength of 8 μm to 13 μm at the second position P2, which is vertically below the first position P1 when the vehicle glass 1 is mounted on the vehicle V. The vehicle glass 1 according to the first embodiment can suppress a decrease in the detection accuracy of far-infrared rays because the average transmittance TR1 and the average transmittance TR2 of the far-infrared transmission member 20 are different.

[0087] Further, it is preferable that the average transmittance TR2 of far-infrared rays with a wavelength of 8 μm to 13 μm at the second position P2 is higher than the average transmittance TR1 of far-infrared rays with a wavelength of 8 μm to 13 μm at the first position P1 when the far-infrared transmission member 20 is irradiated with far-infrared rays in a direction perpendicular to the outer surface 20a of the vehicle exterior. Thereby, even when the vehicle glass 1 is mounted obliquely, the intensity of far-infrared rays transmitted through the first position P1 and incident on the far-infrared camera CA1 can be made close to the intensity of far-infrared rays transmitted through the second position P2 and incident on the far-infrared camera CA1, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0088] Further, it is preferable that the average transmittance of far-infrared rays with a wavelength of 8 μm to 13 μm when the far-infrared transmission member 20 is irradiated with far-infrared rays in a direction perpendicular to the outer surface 20a of the vehicle exterior increases from the first position P1 to the second position P2. Thereby, even when the vehicle glass 1 is mounted obliquely, the intensity of far-infrared rays transmitted through the far-infrared transmission member 20 and incident on the far-infrared camera CA1 can be made uniformly close, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0089] Further, it is preferable that the far-infrared transmission member 20 includes a base material 30 that transmits far-infrared rays and a functional film 32 formed on the base material 30. Thereby, the vehicle glass 1 can appropriately transmit far-infrared rays.

[0090] Further, the functional film 32 preferably includes a far-infrared absorption layer 36. The far-infrared absorption layer 36 absorbs far-infrared rays and has a thickness that decreases from the first position P1 toward the second position P2. Thereby, the vehicle glass 1 can make the intensity of the far-infrared rays transmitted through the far-infrared transmission member 20 and incident on the far-infrared camera CA1 approach uniformity, and can suppress a decrease in the detection accuracy of the far-infrared rays.

[0091] Further, the base material 30 preferably contains at least one material selected from the group consisting of Si, Ge, ZnS, and chalcogenide glass. By making the base material 30 such a material, the vehicle glass 1 can appropriately transmit far-infrared rays.

[0092] Further, the far-infrared transmission member 20 preferably includes a base material 30 that transmits far-infrared rays and a visible light absorption layer 38 formed on the base material 30 and mainly composed of a metal oxide. By including the visible light absorption layer 38, the far-infrared transmission member 20 becomes difficult to be visually recognized by people and less conspicuous. In particular, the far-infrared transmission member 20 may be disposed within a light-shielding region A2 formed of black ceramics or the like, and it is preferable to enhance the appearance affinity with the light-shielding region A2. By including the visible light absorption layer 38, the far-infrared transmission member 20 has a high appearance affinity with the light-shielding region A2, and the design property is ensured.

[0093] Further, the visible light absorption layer 38 is NiO x 、CuO x and MnO x and preferably contains at least one material selected from the group as the main component. By making the material of the visible light absorption layer 38 like this, the visible light can be appropriately absorbed, and the design property of the far-infrared transmission member 20 can be appropriately ensured.

[0094] (First Modified Example) Next, a first modification of the first embodiment will be described. In the first embodiment, by changing the thickness of the far-infrared absorption layer 36, the average transmittance TR1 at the first position PA1 and the average transmittance TR2 at the second position PA2 were made different. However, the method of making the average transmittance TR1 and the average transmittance TR2 different is not limited to this. For example, as described in the first modification, the average transmittance TR1 and the average transmittance TR2 may be made different by changing the thickness of the antireflection film. Parts of the configuration that are common to the first embodiment in the first modification will be omitted from the description. Note that the first modification is also applicable to the first embodiment. That is, while changing the thickness of the far-infrared absorption layer 36 as in the first embodiment, the thickness of the antireflection film may be changed as in the first modification.

[0095] FIG. 9 is a schematic cross-sectional view of the far-infrared transmitting member according to the first modification. As shown in FIG. 9, the far-infrared transmitting member 20 of the first modification includes a functional film 32 including an antireflection film 34S but does not include a far-infrared absorption layer 36. However, in the first modification, the far-infrared absorption layer 36 may be included.

[0096] The antireflection film 34S of the first modification suppresses the reflection of far-infrared rays and absorbs a part of the incident far-infrared rays. That is, the antireflection film 34S has the functions of an AR film and a far-infrared absorption layer. The antireflection film 34S preferably has an average attenuation coefficient with respect to light having a wavelength of 8 μm to 13 μm of 0.01 or more and 0.1 or less, and more preferably 0.02 or more and 0.05 or less. By setting the attenuation coefficient and the average attenuation coefficient within this range, a part of the far-infrared rays can be appropriately absorbed.

[0097] The antireflection film 34S preferably has a different thickness DC1 at the first position P1 and a different thickness DC2 at the second position P2. By making the thickness DC1 and the thickness DC2 different, the average transmittance TR1 and the average transmittance TR2 can be made different, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0098] The antireflection film 34S preferably has a thickness DC2 at the second position P2 that is smaller than the thickness DC1 at the first position P1. By making the thickness DC2 smaller than the thickness DC1, the average transmittance TR2 can be made higher than the average transmittance TR1, suppressing a decrease in the detection accuracy of far-infrared rays.

[0099] Furthermore, in the first modification, the antireflection film 34S preferably has a thickness that decreases as it goes in the Y direction (as it goes vertically downward when mounted on a vehicle). Therefore, it can be said that the antireflection film 34S preferably has a decreasing thickness as it goes from the first position P1 to the second position P2. By making the thickness decrease as it goes toward the second position P2, the average transmittance can be increased as it goes toward the second position P2, suppressing a decrease in the detection accuracy of far-infrared rays.

[0100] The antireflection film 34S includes a high refractive index layer 34A and a low refractive index layer 34B. The laminated structure of the high refractive index layer 34A and the low refractive index layer 34B is the same as that of the first embodiment, so the description is omitted. Note that the antireflection film 34S is not limited to the configuration including the high refractive index layer 34A and the low refractive index layer 34B.

[0101] The high refractive index layer 34A of the first modification preferably has different thicknesses at the first position P1 and the second position P2. Also, the high refractive index layer 34A of the first modification preferably has a smaller thickness at the second position P2 than at the first position P1. Also, the high refractive index layer 34A of the first modification preferably has a thickness that decreases as it goes in the Y direction (as it goes vertically downward when mounted on a vehicle). Therefore, it can be said that the high refractive index layer 34A of the first modification preferably has a decreasing thickness as it goes from the first position P1 to the second position P2.

[0102] The high refractive index layer 34A of the first modification may be the same as that of the first embodiment except that the thickness is different for each position as described above.

[0103] The low refractive index layer 34B of the first modified example preferably has different thicknesses at the first position P1 and the second position P2. Further, in the low refractive index layer 34B of the first modified example, it is preferable that the thickness at the second position P2 is smaller than the thickness at the first position P1. Further, it is preferable that the thickness of the low refractive index layer 34B of the first modified example decreases as it goes in the Y direction (as it goes downward in the vertical direction when mounted on a vehicle). Therefore, it can be said that the thickness of the low refractive index layer 34B of the first modified example preferably decreases as it goes from the first position P1 to the second position P2.

[0104] The low refractive index layer 34B of the first modified example may be the same as that of the first embodiment except that the thickness is different for each position as described above.

[0105] As described above, in the first modified example, by changing the thickness for each position of the high refractive index layer 34A and the low refractive index layer 34B, the thickness for each position of the antireflection film 34S which is a laminate is changed. However, the method of changing the thickness for each position of the antireflection film 34S is not limited thereto. For example, for at least one of the high refractive index layer 34A and the low refractive index layer 34B, the thickness for each position may be changed as described above.

[0106] Also, for example, without changing the thickness for each position of the high refractive index layer 34A and the low refractive index layer 34B, by changing the number of laminations of the high refractive index layer 34A and the low refractive index layer 34B for each position, the thickness for each position of the antireflection film 34S may be changed. In this case, it is preferable that the number of laminations of the antireflection film 34S at the first position P1 and the number of laminations at the second position P2 are different. Further, it is preferable that the number of laminations of the antireflection film 34S at the second position P2 is smaller than the number of laminations at the first position P1. Further, it is preferable that the number of laminations of the antireflection film 34S decreases as it goes in the Y direction (as it goes downward in the vertical direction when mounted on a vehicle). Therefore, it can be said that the number of laminations of the antireflection film 34S preferably decreases as it goes from the first position P1 to the second position P2.

[0107] FIG. 10 is a schematic cross-sectional view of a far-infrared transmission member according to another example of the first modification. In the example of FIG. 9, the functional film 32 was formed on the vehicle interior side of the base material 30. However, the present invention is not limited thereto, and as shown in FIG. 10, the functional film 32 may be formed on the vehicle exterior side of the base material 30. Further, the functional film 32 may be provided on both the vehicle interior side and the vehicle exterior side of the base material 30. For example, the functional film 32 of FIG. 10 may be further formed on the far-infrared transmission member 20 of FIG. 9. That is, the functional film 32 may be provided on at least one of the vehicle interior side and the vehicle exterior side of the base material 30. Also in the first modification, as in the first embodiment, other layers such as the visible light absorption layer 38 may be laminated.

[0108] As described above, in the first modification, the functional film 32 includes an antireflection film 34S that absorbs far-infrared rays and suppresses reflection of far-infrared rays, and whose thickness decreases from the first position P1 to the second position P2. Thereby, the vehicle glass 1 can make the intensity of the far-infrared rays transmitted through the far-infrared transmission member 20 and incident on the far-infrared camera CA1 approach uniformity, and can suppress a decrease in the detection accuracy of far-infrared rays.

[0109] (Second Modification) Next, a second modification of the first embodiment will be described. The second modification makes the average transmittance TR1 and the average transmittance TR2 different by changing the thickness of the base material. Parts of the configuration of the second modification that are common to the first embodiment will be omitted from the description. Note that the second modification is also applicable to the first embodiment and the first modification. That is, while changing the thicknesses of the far-infrared absorption layer and the antireflection film as in the first embodiment and the first modification, the thickness of the base material may be changed as in the second modification.

[0110] FIG. 11 is a schematic cross-sectional view of a far-infrared transmission member according to the second modification. As shown in FIG. 11, the far-infrared transmission member 20 of the second modification includes an antireflection film 34 in the functional film 32, but does not include a far-infrared absorption layer 36. However, in the second modification, the far-infrared absorption layer 36 may be included.

[0111] The base material 30A of the second modification example absorbs a part of the incident far-infrared rays and transmits the other part. That is, the base material 30A has the function of a member that transmits far-infrared rays and the function of a far-infrared absorption layer. The base material 30A preferably has an average attenuation coefficient with respect to light having a wavelength of 8 μm to 13 μm of 0.00001 or more and 0.0005 or less, and more preferably 0.00002 or more and 0.0002 or less. By making the attenuation coefficient and the average attenuation coefficient fall within this range, a part of the far-infrared rays can be appropriately absorbed.

[0112] It is preferable that the thickness DD1 at the first position P1 and the thickness DD2 at the second position P2 of the base material 30A are different. By making the thickness DD1 and the thickness DD2 different, the average transmittance TR1 and the average transmittance TR2 can be made different, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0113] It is preferable that the thickness DD2 at the second position P2 of the base material 30A is smaller than the thickness DD1 at the first position P1. By making the thickness DD2 smaller than the thickness DD1, the average transmittance TR2 can be made higher than the average transmittance TR1, and a decrease in the detection accuracy of far-infrared rays can be suppressed. For example, the thickness DD2 is preferably 25% or more and 90% or less, more preferably 30% or more and 80% or less, and still more preferably 40% or more and 70% or less with respect to the thickness DD1. By making the ratio of the thicknesses fall within this range, a decrease in the detection accuracy of far-infrared rays can be appropriately suppressed.

[0114] Furthermore, in the second modification example, it is preferable that the thickness of the base material 30A decreases as it goes in the Y direction (as it goes vertically downward when mounted on a vehicle). Therefore, it can be said that it is preferable that the thickness of the base material 30A decreases as it goes from the first position P1 to the second position P2. By making the thickness decrease as it goes toward the second position P2, the average transmittance can be increased as it goes toward the second position P2, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0115] Further, the base material 30A preferably has a thickness of the thinnest part of 1.5 mm or more and 4.5 mm or less, preferably 1.6 mm or more and 4.0 mm or less, and preferably 1.8 mm or more and 3.0 mm or less. By setting the thickness of the thinnest part within this range, while maintaining the strength of the far-infrared ray transmitting member, the far-infrared rays can be appropriately absorbed, and a decrease in the detection accuracy of the far-infrared rays can be suppressed.

[0116] FIG. 12 is a schematic cross-sectional view of a far-infrared ray transmitting member according to another example of the second modification. In the example of FIG. 11, the functional film 32 was formed on the vehicle interior side of the base material 30A. However, the present invention is not limited thereto, and as shown in FIG. 12, the functional film 32 may be formed on the vehicle exterior side of the base material 30A. Further, the functional film 32 may be provided on both the vehicle interior side and the vehicle exterior side of the base material 30. For example, the functional film 32 of FIG. 12 may be further formed on the far-infrared ray transmitting member 20 of FIG. 11. That is, the functional film 32 may be provided on at least one of the vehicle interior side and the vehicle exterior side of the base material 30A. Also in the second modification, similar to the first embodiment, other layers such as the visible light absorption layer 38 may be laminated.

[0117] As described above, in the second modification, the far-infrared ray transmitting member 20 includes a base material 30A that absorbs a part of the incident far-infrared rays and transmits a part thereof, and whose thickness becomes thinner as it goes from the first position P1 to the second position P2. Thereby, the vehicle glass 1 can make the intensity of the far-infrared rays transmitted through the far-infrared ray transmitting member 20 and incident on the far-infrared camera CA1 closer to uniform, and a decrease in the detection accuracy of the far-infrared rays can be suppressed.

[0118] (Second Embodiment) Next, the second embodiment will be described. In the first embodiment and each modification, as the thickness decreases toward the second position P2 and the absorption rate of far-infrared rays decreases toward the second position P2, the transmittance of far-infrared rays increases toward the second position P2. However, the method of increasing the transmittance of far-infrared rays toward the second position P2 is not limited to this. For example, as described in the second embodiment, the transmittance of far-infrared rays may be increased toward the second position P2 by decreasing the reflectance of far-infrared rays toward the second position P2. In the second embodiment, the description of the parts having the same configuration as those in the first embodiment will be omitted. Note that the second embodiment is also applicable to the first embodiment and the second modification.

[0119] FIG. 13 is a schematic cross-sectional view of a far-infrared ray transmitting member according to the second embodiment. As shown in FIG. 13, the far-infrared ray transmitting member 20 of the second embodiment includes an antireflection film 34T in a functional film 32. The antireflection film 34T according to the second embodiment is set such that the reflectance of far-infrared rays increases as the thickness increases. In the second embodiment, the functional film 32 does not include a far-infrared ray absorption layer 36. However, the far-infrared ray absorption layer 36 may also be included in the second embodiment.

[0120] (Thickness of far-infrared ray transmitting member) It is preferable that the far-infrared ray transmitting member 20 of the second embodiment has different thicknesses DTA1 at the first position P1 and DTA2 at the second position P2. By making the thickness DTA1 and the thickness DTA2 different, the average transmittance TR1 and the average transmittance TR2 can be made different, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0121] It is preferable that the thickness DTA2 of the far-infrared ray transmitting member 20 of the second embodiment is larger than the thickness DTA1 at the first position P1. By making the thickness DTA2 larger than the thickness DTA1, the average transmittance TR2 can be made higher than the average transmittance TR1, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0122] Furthermore, in the second embodiment, it is preferable that the far-infrared transmission member 20 increases in thickness as it goes in the Y direction (as it goes downward in the vertical direction when mounted on a vehicle). Therefore, it can also be said that it is preferable that the far-infrared transmission member 20 increases in thickness as it goes from the first position P1 to the second position P2. By increasing the thickness as it goes toward the second position P2, the average transmittance can be increased as it goes toward the second position P2, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0123] (Thickness of the antireflection film) It is preferable that the thickness DTB1 of the antireflection film 34T at the first position P1 is different from the thickness DTB2 at the second position P2. By making the thickness DTB1 different from the thickness DTB2, the average transmittance TR1 and the average transmittance TR2 can be made different, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0124] It is preferable that the thickness DTB2 of the antireflection film 34T at the second position P2 is larger than the thickness DTB1 at the first position P1. By making the thickness DTB2 larger than the thickness DTB1, the average transmittance TR2 can be made higher than the average transmittance TR1, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0125] Furthermore, it is preferable that the antireflection film 34T increases in thickness as it goes in the Y direction (as it goes downward in the vertical direction when mounted on a vehicle). Therefore, it can be said that it is preferable that the antireflection film 34T increases in thickness as it goes from the first position P1 to the second position P2. By increasing the thickness as it goes toward the second position P2, the average transmittance can be increased as it goes toward the second position P2, and a decrease in the detection accuracy of far-infrared rays can be suppressed.

[0126] The antireflection film 34T includes a high refractive index layer 34A and a low refractive index layer 34B. Since the laminated structure of the high refractive index layer 34A and the low refractive index layer 34B is the same as that of the first embodiment, the description thereof is omitted. Note that the antireflection film 34T is not limited to the configuration including the high refractive index layer 34A and the low refractive index layer 34B.

[0127] In the second embodiment, it is preferable that the thickness of the high refractive index layer 34A at the first position P1 is different from the thickness at the second position P2. Also, in the second embodiment, it is preferable that the thickness of the high refractive index layer 34A at the second position P2 is larger than the thickness at the first position P1. Further, in the second embodiment, it is preferable that the thickness of the high refractive index layer 34A increases as it goes in the Y direction (as it goes downward in the vertical direction when mounted on a vehicle). Therefore, it can be said that in the second embodiment, it is preferable that the thickness of the high refractive index layer 34A increases as it goes from the first position P1 to the second position P2.

[0128] The high refractive index layer 34A of the second embodiment may be the same as that of the first embodiment except that the thickness is different for each position as described above.

[0129] In the second embodiment, it is preferable that the thickness of the low refractive index layer 34B at the first position P1 is different from the thickness at the second position P2. Also, in the second embodiment, it is preferable that the thickness of the low refractive index layer 34B at the second position P2 is larger than the thickness at the first position P1. Further, in the second embodiment, it is preferable that the thickness of the low refractive index layer 34B increases as it goes in the Y direction (as it goes downward in the vertical direction when mounted on a vehicle). Therefore, it can be said that in the second embodiment, it is preferable that the thickness of the low refractive index layer 34B increases as it goes from the first position P1 to the second position P2.

[0130] The low refractive index layer 34B of the second embodiment may be the same as that of the first embodiment except that the thickness is different for each position as described above.

[0131] Thus, in the second embodiment, by changing the thickness for each position of the high refractive index layer 34A and the low refractive index layer 34B, the thickness for each position of the antireflection film 34T which is a laminate is changed. However, the method of changing the thickness for each position of the antireflection film 34T is not limited thereto. For example, for at least one of the high refractive index layer 34A and the low refractive index layer 34B, the thickness for each position may be changed as described above.

[0132] For example, without changing the thickness for each position of the high refractive index layer 34A and the low refractive index layer 34B, the thickness for each position of the antireflection film 34T may be changed by changing the number of stacked layers of the high refractive index layer 34A and the low refractive index layer 34B for each position. In this case, it is preferable that the number of stacked layers at the first position P1 is different from the number of stacked layers at the second position P2 for the antireflection film 34T. Further, it is preferable that the number of stacked layers at the second position P2 is larger than the number of stacked layers at the first position P1 for the antireflection film 34T. Further, it is preferable that the number of stacked layers of the antireflection film 34T increases as it goes in the Y direction (as it goes downward in the vertical direction when mounted on a vehicle). Therefore, it can be said that it is preferable that the number of stacked layers of the antireflection film 34T increases as it goes from the first position P1 to the second position P2.

[0133] FIG. 14 is a schematic cross-sectional view of a far-infrared transmitting member according to another example of the second embodiment. In the example of FIG. 13, the functional film 32T was formed on the vehicle interior side of the base material 30, but it is not limited thereto, and as shown in FIG. 14, the functional film 32T may be formed on the vehicle exterior side of the base material 30. Further, the functional film 32T may be provided on both the vehicle interior side and the vehicle exterior side of the base material 30. For example, the functional film 32T of FIG. 14 may be further formed on the far-infrared transmitting member 20 of FIG. 13. That is, the functional film 32T may be provided on at least one of the vehicle interior side and the vehicle exterior side of the base material 30. Also in the second embodiment, as in the first embodiment, other layers such as the visible light absorption layer 38 may be laminated.

[0134] As described above, in the second embodiment, it is preferable that the functional film 32 includes an antireflection film 34T that suppresses reflection of far-infrared rays and whose thickness increases from the first position P1 to the second position P2. Thereby, the vehicle glass 1 can reduce the reflectance of far-infrared rays as it goes toward the second position P2, and make the intensity of the far-infrared rays transmitted through the far-infrared transmitting member 20 and incident on the far-infrared camera CA1 approach uniformity, and suppress a decrease in the detection accuracy of far-infrared rays.

[0135] Further, the antireflection film 34T is composed of a plurality of layers stacked, and the number of stacked layers may increase as it goes from the first position P1 to the second position P2. Thereby, the vehicle glass 1 can reduce the reflectance of far-infrared rays as it goes toward the second position P2, and make the intensity of the far-infrared rays transmitted through the far-infrared ray transmission member 20 and incident on the far-infrared camera CA1 approach uniformity, and it becomes possible to suppress a decrease in the detection accuracy of far-infrared rays.

[0136] Further, the antireflection film 34T is composed of a plurality of layers stacked, and the thickness of at least one layer may increase as it goes from the first position P1 to the second position P2. Thereby, the vehicle glass 1 can reduce the reflectance of far-infrared rays as it goes toward the second position P2, and make the intensity of the far-infrared rays transmitted through the far-infrared ray transmission member 20 and incident on the far-infrared camera CA1 approach uniformity, and it becomes possible to suppress a decrease in the detection accuracy of far-infrared rays.

[0137] Next, examples will be described. <Fabrication of Far-Infrared Ray Transmission Member> First, as a substrate, Si (FZ grade) with a diameter of 50 mm and a thickness of 2.0 ± 0.05 mm was prepared. The thicknesses of the substrate and the functional film were measured with a digital caliper (manufactured by Mitutoyo Corporation, CD-15CX). (Example 1) On the surface of the above substrate on the outside of the vehicle, a diamond-like carbon (DLC) film with a thickness of 1000 nm was formed by plasma CVD as a protective film. Then, while tilting the substrate, a Ge film and then a ZnS film were formed by evaporation on the surface of the substrate on the inside of the vehicle as an antireflection film. When the obtained far-infrared ray transmission member was mounted on a vehicle with the upper end in the Y direction as the origin, and the position of P1 was 5 mm and the position of P2 was 45 mm, the film thicknesses of the respective layers at P1 and P2 were as shown in Table 1. (Example 2) While tilting the above substrate, an NiO x film was formed on the surface of the substrate on the outside of the vehicle by magnetron sputtering as an antireflection film. The film thicknesses of the respective layers at P1 and P2 were as shown in Table 1. (Example 3) After depositing a 150 nm Ge film on the surface of the above base material facing the inside of the vehicle by vapor deposition, while tilting the base material, NiO was deposited by magnetron sputtering x to form a film, which was used as an antireflection film. The film thicknesses of each layer at P1 and P2 were as shown in Table 1. (Example 4) On the surface of the above base material facing the outside of the vehicle, a 1200 nm NiO x film was deposited by magnetron sputtering to form an antireflection film. Then, while tilting the base material, an Al2O3 film was deposited on the surface of the base material facing the inside of the vehicle in the same manner by magnetron sputtering to form a far-infrared absorption layer. The film thicknesses of each layer at P1 and P2 were as shown in Table 1. (Example 5) A far-infrared transmission member was fabricated in the same manner as in Example 1, except that the antireflection film was deposited without tilting the base material. The film thicknesses of each layer at P1 and P2 were as shown in Table 1. (Example 6) On the surface of the above base material facing the outside of the vehicle, a 1000 nm NiO x film, a 25 nm ZrO2 film, a 15 nm NiO x film, and a 200 nm ZrO2 film were deposited in this order in the direction away from the base material by magnetron sputtering to form an antireflection film. Then, while tilting the base material, an NiO x film was deposited on the surface of the base material facing the inside of the vehicle in the same manner by magnetron sputtering to form a far-infrared absorption layer. The film thicknesses of each layer at P1 and P2 were as shown in Table 1.

[0138] <Average Transmittance Evaluation of P1 and P2 of the Far-Infrared Transmission Member> The infrared transmission spectra of the far-infrared transmission members obtained in Examples 1 to 6 were measured at the positions of P1 and P2 respectively using a Fourier transform infrared spectrometer (manufactured by Thermo Scientific, product name: Nicolet iS10), and the average transmittance in the wavelength range of 8 μm to 13 μm was obtained from the obtained infrared transmission spectra. <Fabrication and Installation of the Far-Infrared Transmission Window> First, a laminated glass was prepared by placing PVB with a thickness of 0.76 mm between soda-lime glasses with a size of 300 mm × 300 mm and a thickness of 2.0 mm. Next, a through-hole with a diameter of φ53.5 mm was formed at the center of the laminated glass, and the infrared transmission members obtained in Examples 1 to 5 were attached to the through-hole through the attachment of the resin molding to form a far-infrared transmission window. <Actual measurement evaluation of thermal image of far-infrared transmission window> For the evaluation, a plane blackbody furnace (manufactured by A.R. System Co., Ltd., DBB-LC50) and a far-infrared camera (manufactured by FLIR, Boson640, HFOV: 18°) were used. The mounting angle (tilt angle with respect to the vertical direction) of the far-infrared transmission window was set to 30°, and the position of the far-infrared camera was adjusted while observing the thermal image so that the field of view angle of the far-infrared camera was not blocked by the far-infrared transmission window, and the far-infrared transmission window was fixed. Next, through the far-infrared transmission window, a plane blackbody furnace was arranged so that the focus of the far-infrared camera was adjusted, the temperature of the plane blackbody furnace was set to 50°C, and after waiting until the temperature became constant, a thermal image evaluation was performed. For the evaluation of the thermal image, after saving the thermal image in grayscale, using image processing software, the luminance distribution was analyzed in the Y direction (vertical direction of the vehicle), and the luminance difference at the positions of P1 and P2 at the center in the X direction was evaluated as P2 / P1 (%). <Simulation evaluation of thermal image of far-infrared transmission window> In addition, using optical simulation software (Ocean manufactured by Eclat Digital Research), similar to the actual measurement, an infrared radiation object, a far-infrared transmission window, and a far-infrared camera that simulated a blackbody furnace at 50°C (323K) were arranged to evaluate the radiant luminance. From the obtained evaluated luminance distribution, the luminance difference at the positions of P1 and P2 was evaluated as P2 / P1 sim (%). Note that assuming that the heat release from the infrared radiation object can be approximated by Lambertian, the calculation was performed from the transmittance at the mounting angle of each far-infrared transmission member. (Example 7: Reference example) The thermal image was evaluated in the same manner as in Example 1 except that the mounting angle of the far-infrared transmission window in Example 1 was set to 90°. The results are shown in Table 1.

[0139]

Table 1

[0140] In Examples 1, 5, and 7, actual measurement evaluation and simulation evaluation of the thermal image were performed, and in Examples 2 to 4 and 6, only simulation evaluation was performed. From Examples 1, 5, and 7, the luminance difference P2 / P1 in the actual measurement results and the luminance difference P2 / P1 in the simulation evaluation sim show a good agreement. As shown in Table 1, in Example 5, which is a comparative example, since the antireflection film was formed without tilting the substrate, when irradiating far-infrared rays in a direction perpendicular to the surface on the outside of the vehicle, the average transmittance of far-infrared rays at position P1 and the average transmittance of far-infrared rays at position P2 are the same. In Example 5, it can be seen that the luminance difference P2 / P1 is 80% and the luminance variation within the field of view of the far-infrared camera is large, and there is a risk of deterioration in the detection accuracy of infrared rays. On the other hand, as shown in Table 1, in Examples 1 to 4 and 6, which are this embodiment, since the antireflection film was formed while tilting the substrate, when irradiating far-infrared rays in a direction perpendicular to the surface on the outside of the vehicle, the average transmittance of far-infrared rays at position P1 and the average transmittance of far-infrared rays at position P2 are different. In Examples 1 to 4 and 6, which are this embodiment, the luminance difference P2 / P1, or P2 / P1 sim is within 90 to 110%, and it can be said that the deterioration in the detection accuracy of infrared rays is suppressed.

[0141] As described above, the embodiments of the present invention have been described, but the embodiments are not limited by the content of this embodiment. Further, the above-described components include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or changes of the components can be made without departing from the gist of the above-described embodiments.

Explanation of Signs

[0142] 1 Vehicle glass 10, 12, 14 Glass substrate 16 Intermediate layer 18 Light-shielding layer 19 Opening 20 Far-infrared transmission member 30 Base material 32 Functional film 34 Anti-reflection film 36 Far-infrared absorption layer P1 First position P2 Second position V Vehicle

Claims

1. A vehicle glass having a light-shielding region, wherein a far-infrared transmission region is formed in the light-shielding region, the far-infrared transmission region including an opening and a far-infrared transmission member disposed in the opening; when the far-infrared transmission member is irradiated with far-infrared rays in a direction perpendicular to the outer surface of the vehicle, the average transmittance of far-infrared rays having a wavelength of 8 μm to 13 μm at a second position is higher than the average transmittance of far-infrared rays having a wavelength of 8 μm to 13 μm at a first position that is vertically above the second position when the vehicle glass is mounted on a vehicle; the length of the longest straight line among the straight lines connecting any two points in the plane of the outer surface of the vehicle of the far-infrared transmission member is 80 mm or less; a vehicle glass.

2. The vehicle glass according to claim 1, wherein when the far-infrared transmission member is irradiated with far-infrared rays in a direction perpendicular to the outer surface of the vehicle, the average transmittance of far-infrared rays having a wavelength of 8 μm to 13 μm increases from the first position toward the second position.

3. The vehicle glass according to claim 1 or claim 2, wherein the far-infrared transmission member includes a base material that transmits far-infrared rays and a functional film formed on the base material.

4. The vehicle glass according to claim 3, wherein the functional film includes a far-infrared absorption layer that absorbs far-infrared rays and has a thickness that decreases from the first position toward the second position.

5. The vehicle glass according to claim 3, wherein the functional film includes an antireflection film that absorbs far-infrared rays and suppresses reflection of far-infrared rays and has a thickness that decreases from the first position toward the second position.

6. The vehicle glass according to claim 1 or claim 2, wherein the far-infrared transmission member includes a base material that absorbs part of the incident far-infrared rays and transmits part of the incident far-infrared rays and has a thickness that decreases from the first position toward the second position.

7. The vehicle glass according to claim 3, wherein the functional film includes an antireflection film that suppresses reflection of far-infrared rays and has a thickness that increases from the first position toward the second position.

8. The vehicle glass according to claim 7, wherein the antireflection film is formed by laminating a plurality of layers, and the number of laminated layers increases from the first position toward the second position.

9. The vehicle glass according to claim 7, wherein the antireflection film is formed by laminating a plurality of layers, and the thickness of at least one layer increases from the first position toward the second position.

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

11. The vehicle glass according to claim 1 or claim 2, wherein, among the straight lines connecting any two points in the plane on the outer side of the vehicle, the length of the longest straight line is 40 mm or more.

12. The vehicle glass according to claim 1 or claim 2, wherein the thickness of the far-infrared transmission member is 1.5 mm or more and 5.5 mm or less.

Images