Vehicular infrared sensor device and image processing method

Abstract

A vehicular infrared sensor device (200) comprises vehicular glass (1) having a light-blocking region (A2) provided with an infrared transmission region (B) in which an infrared transmission member (20) is disposed in an opening (19), and an image processing unit (8) for performing image processing on an image (2) captured by an infrared camera (CA1) disposed at a position facing the infrared transmission region (B). The infrared transmission member (20) has a base material layer (22), and a prism layer (24) having a plurality of prism parts (26) formed continuously in a direction (Y) on the obverse surface of the base material layer (22). Each of the prism parts (26) has an inclined surface (30) extending from the obverse surface of the base material layer (22), a connection surface (32) connecting to the inclined surface (30) and extending to the obverse-surface side of the base material layer (22), and a folded-back part (33) including a connection part (34) between the inclined surface (30) and the connection surface (32). The image processing unit (8) reduces noise that is included in the captured image (2) and generated by the folded-back part (33).

Description

Infrared sensor device for vehicle and image processing method

[0001] The present invention relates to an infrared sensor device for a vehicle and an image processing method.

[0002] To improve automobile safety, an infrared sensor device is installed in a vehicle. In this infrared sensor device, an infrared-transmitting area having an infrared-transmitting member is provided on the windshield of the vehicle, and infrared light that passes through this infrared-transmitting member is captured by an infrared camera installed inside the vehicle.

[0003] Infrared rays are classified according to their wavelength bands into near-infrared rays (for example, wavelengths of 0.7 μm to 2 μm), mid-infrared rays (for example, wavelengths of 3 μm to 5 μm), and far-infrared rays (for example, wavelengths of 8 μm to 13 μm). Infrared sensors that detect these infrared rays include touch sensors, near-infrared cameras, or LiDAR for near-infrared rays, gas analyzers or mid-infrared spectroscopic analyzers (functional group analysis) for mid-infrared rays, and far-infrared cameras for far-infrared rays. Specific examples of far-infrared cameras include night vision cameras and thermoviewers.

[0004] Because automobile window glass typically transmits very little far-infrared light with wavelengths of 8 μm to 13 μm, infrared cameras have traditionally been installed outside the vehicle cabin, more specifically, on the front grille, as in Patent Document 1, for example. However, installing an infrared camera outside the vehicle cabin requires a more complex structure to ensure robustness, water resistance, dust resistance, and the like, leading to higher costs. By installing an infrared camera inside the vehicle cabin, specifically in the wiper operating area, the infrared camera is protected by the window glass and dirt can be wiped away, solving these problems. However, as mentioned above, because window glass has the problem of transmitting very little far-infrared light, infrared cameras were not typically installed inside the vehicle cabin.

[0005] In order to meet the above demands, Patent Document 2 discloses a window member in which a through hole is formed in a part of the window glass and filled with an infrared-transmitting material.

[0006] US Patent Application Publication No. 2003 / 0169491 UK Patent Application Publication No. 2271139

[0007] An infrared camera placed on the inside of a vehicle with respect to the window glass detects infrared rays that pass through a far-infrared transmission area formed in the window glass and captures an image. However, the infrared rays that pass through the window glass may generate noise due to the influence of the far-infrared transmission area, and the noise may appear in the image. This noise may degrade the quality of the image.

[0008] The present invention has been made in view of the above, and has as its object to provide an infrared sensor device for a vehicle and an image processing method that can suppress deterioration in the quality of an image captured by passing through an infrared transmitting area.

[0009] The present invention has the following configuration: (1) A vehicle infrared sensor device comprising: a vehicle glass having a light-blocking area in which an infrared-transmitting area having an infrared-transmitting member disposed within an opening thereof; and an image processing unit that performs image processing on an image captured by an infrared camera disposed opposite the infrared-transmitting area, wherein the infrared-transmitting member has: a base layer; and a prism layer having a plurality of prism portions formed continuously in a first direction on a surface of the base layer, each prism portion having a first surface extending from the surface of the base layer and gradually inclining away from the base layer towards one side of the first direction, a second surface connected to the first surface and extending toward the surface of the base layer, and a folding portion including a connecting portion between the first surface and the second surface, and the image processing unit reduces noise generated in the folding portion and included in the captured image. (2) An image processing method, comprising: capturing an image using an infrared camera that detects infrared rays that pass through an infrared-transmitting area; the infrared-transmitting area being an infrared-transmitting member disposed in an opening provided in a light-shielding area of ​​a vehicle glass; the infrared-transmitting member being an infrared-transmitting member having a base layer and a prism layer having a plurality of prism portions formed continuously in a first direction on a surface of the base layer; the prism portions having a first surface extending from the surface of the base layer and gradually inclining in a direction away from the base layer towards one side of the first direction; a second surface connected to the first surface and extending towards the surface of the base layer; and a folding portion including a connecting portion between the first surface and the second surface; and reducing noise generated in the folding portion and included in the captured image.

[0010] According to the present invention, it is possible to suppress deterioration in the quality of an image captured by passing through an infrared transmitting area.

[0011] FIG. 1 is a schematic diagram showing a state in which a vehicle glass according to this embodiment is mounted on a vehicle. FIG. 2 is a schematic plan view of the vehicle glass according to this embodiment. FIG. 3 is a cross-sectional view taken along line Ca-Ca in FIG. 2. FIG. 4 is a cross-sectional view taken along line Cb-Cb in FIG. 2. FIG. 5 is a schematic diagram showing an example of a state in which the vehicle glass is mounted on a vehicle. FIG. 6 is a plan view of the infrared-transmitting member shown in FIG. 5. FIG. 7 is an enlarged view of a prism portion. FIG. 8 is a diagram showing a pixel matrix consisting of 3 rows and 3 columns for performing image restoration processing. FIG. 9 is a schematic diagram showing the arrangement of a defective region including a defective pixel in a state in which the connection portions and folding portions of the prism portion extend parallel to one of the pixel array directions of the infrared camera. FIG. 10 is a schematic diagram showing the arrangement of a defective region in a state in which the connection portions and folding portions extend in a specific direction that is not parallel to the pixel array direction but intersects with the pixel array direction. FIG. 11 is a diagram showing a modified example of the prism portion. FIG. 12 is a schematic diagram showing the relationship between the attitude and field of view of the infrared camera. Fig. 13 is a schematic diagram showing the relationship between the placement of an infrared camera and the field of view. Fig. 14 is a plan view showing another example of an infrared transparent member. Fig. 15 is a cross-sectional view taken along line Cc-Cc in Fig. 14. Fig. 16 is a schematic cross-sectional view of an infrared transparent member according to a modified example.

[0012] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that the present invention is not limited to these embodiments, and when there are multiple embodiments, the present invention also includes configurations that combine the various embodiments. Numerical values ​​include rounded-off ranges. Furthermore, the use of "to" to indicate a range of values ​​means that the numerical values ​​before and after the range are included as the lower and upper limits.

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

[0014] The vehicle glass 1, the infrared camera CA1, and the visible light camera CA2 constitute a camera unit 100 according to this embodiment. The infrared camera CA1 is a camera that detects infrared rays and captures a thermal image of the exterior of the vehicle V by detecting infrared rays from outside the vehicle V. The visible light camera CA2 is a camera that detects visible light and captures an image of the exterior of the vehicle V by detecting visible light from outside the vehicle V. Note that the camera unit 100 may include, for example, a LiDAR or a millimeter-wave radar in addition to or instead of either the infrared camera CA1 or the visible light camera CA2. Here, infrared rays refer to, for example, electromagnetic waves in a wavelength band of 905 nm to 13 μm, and visible light refers to, for example, electromagnetic waves in a wavelength band of 360 nm to 830 nm. The infrared rays may be electromagnetic waves in the near-infrared wavelength band with wavelengths of 0.905 μm (905 nm), 1.35 μm (1350 nm), or 1.55 μm (1550 nm), or the infrared rays may be electromagnetic waves in the far-infrared wavelength band with wavelengths of 8 μm to 12 μm.

[0015] (Vehicle Glass) FIG. 2 is a schematic plan view of a vehicle glass 1 according to this embodiment. FIG. 3 is a cross-sectional view taken along line Ca-Ca in FIG. 2. FIG. 4 is a cross-sectional view taken along line Cb-Cb in FIG. 2. As shown in FIG. 2, hereinafter, the upper edge of the vehicle glass 1 will be referred to as an upper edge portion 1a, the lower edge as a lower edge portion 1b, one side edge as a side edge portion 1c, and the other side edge as a side edge portion 1d. The upper edge portion 1a is an edge portion located on the upper side in the vertical direction when the vehicle glass 1 is installed in a vehicle V. The lower edge portion 1b is an edge portion located on the lower side in the vertical direction when the vehicle glass 1 is installed in a vehicle V. The side edge portion 1c is an edge portion located on one side when the vehicle glass 1 is installed in a vehicle V. The side edge portion 1d is an edge portion located on the other side when the vehicle glass 1 is installed in a vehicle V.

[0016] Hereinafter, among directions parallel to the surface of the vehicle glass 1, the direction from the upper edge 1a to the lower edge 1b is referred to as the Y direction, and the direction from the side edge 1c to the side edge 1d is referred to as the X direction. In this embodiment, the X direction and the Y direction are perpendicular to each other. The direction perpendicular to the surface of the vehicle glass 1, i.e., the thickness direction of the vehicle glass 1, is referred to as the Z direction. For example, when the vehicle glass 1 is installed in a vehicle V, the Z direction is the direction from the exterior side to the interior side of the vehicle V. The X direction and the Y direction run along the surface of the vehicle glass 1. However, if the surface of the vehicle glass 1 is curved, for example, the X direction and the Y direction may be directions tangent to the surface of the vehicle glass 1 at the center point O of the vehicle glass 1. The center point O is the center position of the vehicle glass 1 when the vehicle glass 1 is viewed from the Z direction.

[0017] The vehicle glass 1 is formed with a light-transmitting region A1 and a light-shielding region A2. The light-transmitting region A1 is a region that occupies the central part of the vehicle glass 1 when viewed from the Z direction. The light-transmitting region A1 is a region that ensures the driver's field of vision. The light-transmitting region A1 is a region that transmits visible light. The light-shielding region A2 is a region that is formed around the light-transmitting region A1 when viewed from the Z direction. The light-shielding region A2 is a region that blocks visible light. Within the light-shielding region A2a, which is the portion of the light-shielding region A2 on the upper edge portion 1a side, an infrared-transmitting region B and a visible light-transmitting region C are formed.

[0018] The infrared-transmitting region B is an area that transmits infrared light and is an area where the infrared camera CA1 is provided. That is, the infrared camera CA1 is provided at a position that overlaps with the infrared-transmitting region B when viewed from the optical axis direction of the infrared camera CA1. The visible-light-transmitting region C is an area that transmits visible light and is an area where the visible-light camera CA2 is provided. That is, the visible-light camera CA2 is provided at a position that overlaps with the visible-light-transmitting region C when viewed from the optical axis direction of the visible-light camera CA2.

[0019] In this way, the light-shielding region A2 has the infrared-transmitting region B and the visible-light-transmitting region C formed therein, so that the light-shielding region A2 blocks infrared light except in the region where the infrared-transmitting region B is formed, and blocks visible light except in the region where the visible-light-transmitting region C is formed. The light-shielding region A2a is formed around the infrared-transmitting region B and the visible-light-transmitting region C. Providing the light-shielding region A2a around the periphery in this way is preferable because it protects the various sensors from sunlight. It is also preferable from the standpoint of design because the wiring of the various sensors is not visible from outside the vehicle.

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

[0021] The glass substrates 12, 14 may be made of, for example, soda-lime glass, borosilicate glass, or aluminosilicate glass. The intermediate layer 16 is an adhesive layer that bonds the glass substrates 12, 14 together. The intermediate layer 16 may be made of, for example, a modified polyvinyl butyral (hereinafter also referred to as PVB) material, an ethylene-vinyl acetate copolymer (EVA)-based material, a urethane resin material, or a polyvinyl chloride resin material. More specifically, the glass substrate 12 includes one surface 12A and another surface 12B, and the other surface 12B is in contact with one surface 16A of the intermediate layer 16 and fixed (adhered) to the intermediate layer 16. The glass substrate 14 includes one surface 14A and another surface 14B, and the one surface 14A is in contact with the other surface 16B of the intermediate layer 16 and fixed (adhered) to the intermediate layer 16. As described above, the vehicle glass 1 is a laminated glass in which the glass substrate 12 and the glass substrate 14 are laminated together. However, the vehicle glass 1 is not limited to a laminated glass, and may be configured to include, for example, only one of the glass substrate 12 and the glass substrate 14. In this case, the intermediate layer 16 may not be provided. Hereinafter, when there is no need to distinguish between the glass substrates 12 and 14, they will be referred to as the glass substrate 10.

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

[0023] In the present embodiment, the side of the vehicle glass 1 on which the light-shielding layer 18 is provided is the interior side of the vehicle V (inside of the vehicle), and the side on which the glass substrate 12 is provided is the exterior side of the vehicle V (outside of the vehicle), but this is not limiting, and the light-shielding layer 18 may be on the exterior side of the vehicle V. When the vehicle glass 1 is configured as a laminated glass of the glass substrates 12, 14, the light-shielding layer 18 may be formed between the glass substrate 12 and the glass substrate 14.

[0024] (Light-shielding region) The light-shielding region A2 is formed by providing the light-shielding layer 18 on the glass base 10. That is, the light-shielding region A2 is a region in which the glass base 10 is provided with the light-shielding layer 18. That is, the light-shielding region A2 is a region in which the glass base 12, the intermediate layer 16, the glass base 14, and the light-shielding layer 18 are laminated. On the other hand, the light-transmitting region A1 is a region in which the glass base 10 is not provided with the light-shielding layer 18. That is, the light-transmitting region A1 is a region in which the glass base 12, the intermediate layer 16, and the glass base 14 are laminated, and the light-shielding layer 18 is not laminated.

[0025] (Infrared-Transmitting Region) As shown in FIG. 3 , the vehicle glass 1 has an opening 19 formed therein, penetrating from one surface (here, surface 12A) to the other surface (here, surface 14B) in the Z direction. 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 a region where the opening 19 and the infrared-transmitting member 20 disposed within the opening 19 are provided. Because the light-shielding layer 18 does not transmit infrared rays, the infrared-transmitting region B is not provided with the light-shielding layer 18. That is, the infrared-transmitting region B does not have the glass base 12, intermediate layer 16, glass base 14, or light-shielding layer 18, and the infrared-transmitting member 20 is provided in the formed opening 19. The infrared-transmitting member 20 will be described later.

[0026] 4, the visible light transmitting region C is, similar to the light-transmitting region A1, a region in the Z direction where the glass base 10 does not include the light-shielding layer 18. In other words, the visible light transmitting region C is a region where the glass base 12, the intermediate layer 16, and the glass base 14 are laminated, and where the light-shielding layer 18 is not laminated.

[0027] As shown in FIG. 2 , the visible light transmission region C is preferably located near the infrared transmission region B. Specifically, the center of the infrared transmission region B as viewed from the Z direction is defined as center point OB, and the center of the visible light transmission region C as viewed from the Z direction is defined as center point OC. If the shortest distance between the infrared transmission region B (opening 19) and the visible light transmission region C as viewed from the Z direction is defined as distance L, distance L is preferably greater than 0 mm and less than 100 mm, and more preferably greater than 10 mm and less than 80 mm. By positioning the visible light transmission region C within this range relative to the infrared transmission region B, it is possible to capture images at close positions with the infrared camera CA1 and the visible light camera CA2, while suppressing the amount of perspective distortion in the visible light transmission region C, allowing the visible light camera CA2 to capture appropriate images. Capturing images at close positions with the infrared camera CA1 and the visible light camera CA2 reduces the load when processing the data obtained from each camera and also optimizes the routing of power and signal cables. Furthermore, by using images from the infrared camera CA1 and the visible light camera CA2, whose optical axes are aligned in the horizontal direction, it is possible to calculate the distance to an object using the principle of a stereo camera. If the visible light camera CA2 is a compound eye stereo camera, the distance information obtained from the visible light camera CA2 can be reflected in the infrared camera CA1, thereby improving the accuracy of distance detection.

[0028] As shown in Fig. 2, the visible light transmitting region C and the infrared transmitting region B are preferably positioned side by side in the X direction. That is, the visible light transmitting region C is preferably not positioned on the Y direction side of the infrared transmitting region B, but is aligned with the infrared transmitting region B in the X direction. By arranging the visible light transmitting region C next to the infrared transmitting region B in the X direction, the visible light transmitting region C can be positioned near the upper edge portion 1a. Therefore, the driver's field of view in the light transmitting region A1 can be appropriately secured.

[0029] (Infrared-Transmitting Member) The infrared-transmitting member 20 provided in the infrared-transmitting region B will now be described in detail. The infrared-transmitting member 20 is a member that transmits infrared rays. As shown in FIG. 3 , the exterior surface of the infrared-transmitting member 20 is preferably formed flush (continuous) with the exterior surface of the light-shielding region A2. In other words, the exterior surface 20A of the infrared-transmitting member 20 is attached so as to be continuous with the surface 12A of the glass substrate 12. By making the surface 20A of the infrared-transmitting member 20 continuous with the surface 12A of the glass substrate 12 in this manner, the wiping effect of the wipers can be prevented from being impaired. Furthermore, the presence of a step can be prevented from impairing the design of the vehicle V, and the risk of sand and dust accumulating on the step can be reduced. Furthermore, the infrared-transmitting member 20 is preferably molded to fit the curved surface shape of the vehicle glass 1 to which it is applied. The molding method for the infrared-transmitting member 20 is not particularly limited, and press molding, polishing, molding, or the like can be selected depending on the curved surface shape and the member.

[0030] The shape of the infrared-transmitting member 20 is not particularly limited, but is preferably a plate-like shape that matches the shape of the opening 19. That is, for example, if the opening 19 is circular, the infrared-transmitting member 20 is preferably a disk-like (cylindrical) shape. The infrared-transmitting member 20 is not limited to a disk-like shape, but may also be elliptical or rectangular. From the standpoint of design, the surface shape of the infrared-transmitting member 20 on the vehicle exterior side may be processed to match the curvature of the outer surface shape of the glass substrate 12. Furthermore, the infrared-transmitting member 20 may be lenticular in order to achieve both a wider viewing angle of the infrared camera CA1 and improved mechanical properties. This configuration is preferable because it allows the infrared-transmitting member 20 to efficiently collect infrared light even if its area is small. In this case, the number of lens-shaped infrared-transmitting members 20 is preferably one to three, and typically two. Furthermore, it is particularly preferable that the lens-shaped infrared transmitting member 20 is pre-aligned and modularized, and is integrated with a housing or bracket that bonds the infrared camera CA1 to the vehicle glass 1.

[0031] In the vehicle glass 1 of this embodiment, as shown in FIG. 3 , when the vehicle glass 1 of this embodiment is a laminated glass including a glass substrate 12 (vehicle exterior side) and a glass substrate 14 (vehicle interior side), the opening 19 is formed by overlapping the opening of the glass substrate 12 and the opening of the glass substrate 14. In this case, the area of ​​the opening of the glass substrate 12 may be made larger than the area of ​​the opening of the glass substrate 14, and the infrared transparent member 20 may be disposed within the opening of the glass substrate 12. This configuration improves the resistance force when the infrared transparent member 20 is pressed from the vehicle exterior and the strength against impact. In another embodiment (not shown), the area of ​​the opening of the glass substrate 12 may be made smaller than the area of ​​the opening of the glass substrate 14, and the infrared transparent member 20 may be disposed within the opening of the glass substrate 12. This configuration allows the alignment processing precision of the opening 19 to be relaxed when the glass substrate 12 (vehicle exterior side) and the glass substrate 14 are laminated with the intermediate layer 16, improving processing yield. In yet another embodiment (not shown), the area of ​​the opening in the glass substrate 12 and the area of ​​the opening in the glass substrate 14 may be the same, and the infrared-transmitting member 20 may be disposed within the opening in the glass substrate 12. In such a configuration, the glass substrates 12 and 14 are laminated together in advance via the intermediate layer 16, and the opening 19 is formed in the laminated glass structure at one time. By forming the opening 19 in the laminated glass structure, the process load for aligning the openings is eliminated, further reducing the number of processing steps and lowering manufacturing costs, compared to when an opening is provided in each of the glass substrates 12 (exterior side of the vehicle) and 14 (interior side of the vehicle). The relationship between the size of the opening in the glass substrate 12 and the size of the opening in the glass substrate 14 may be appropriately selected taking into account the above-mentioned advantages.

[0032] As shown in FIG. 3 , in the infrared-transmitting member 20, the length d1 of the longest straight line connecting any two points on the vehicle exterior surface is preferably 80 mm or less. The length d1 is more preferably 70 mm or less, and even more preferably 65 mm or less. The length d1 is preferably 40 mm or more. The length d1 is more preferably 50 mm or more, and even more preferably 60 mm or more. As shown in FIG. 3 , in the opening 19 of the infrared-transmitting region B, the length d2 of the longest straight line connecting any two points on the vehicle exterior surface (here, any two points on the edge of the opening 19 on the surface 12A side) is preferably 80 mm or less. The length d2 is more preferably 70 mm or less, and even more preferably 65 mm or less. The length d2 is preferably 40 mm or more. The length d2 is more preferably 50 mm or more, and even more preferably 60 mm or more. The length d2 can also be considered the length of the longest straight line connecting any two points on the periphery of the opening 19 on the vehicle exterior surface (surface 12A) of the vehicle glass 1. By setting the length d1 of the infrared-transmitting member 20 and the length d2 of the opening 19 within this range, a decrease in the strength of the vehicle glass 1 can be suppressed, and the amount of perspective distortion around the opening 19 can also be suppressed. Note that, when the shape of the vehicle exterior surface of the infrared-transmitting member 20 is circular, the lengths d1 and d2 correspond to the diameter of the vehicle exterior surface. Furthermore, the lengths d1 and d2 refer to the length of the vehicle glass 1 when it is installed in the vehicle V. For example, if the glass is bent to have a shape to be installed in the vehicle V, the lengths d1 and d2 refer to the length of the vehicle glass 1 after the bending process. The same applies to the dimensions and positions other than the lengths d1 and d2 unless otherwise specified. The infrared-transmitting member 20 may be attached to the opening 19 via a frame member provided on its outer periphery.

[0033] Fig. 5 is a schematic diagram showing an example of a state in which the vehicle glass 1 is attached to a vehicle. Here, as shown in Fig. 5, if the downward vertical direction is defined as direction YV, the direction Y of the vehicle glass 1 attached to the vehicle V is inclined with respect to direction YV, and the vehicle exterior surface 20A of the infrared transparent member 20 is also inclined with respect to direction YV. Fig. 6 is a plan view of the infrared transparent member 20.

[0034] The infrared-transmitting member 20 includes a substrate layer 22 and a prism layer 24. The prism layer 24 is provided on a vehicle-interior-facing surface 22a of the substrate layer 22. The vehicle-interior-facing surface 22a of the substrate layer 22 is parallel to the vehicle-exterior-facing surface 20A of the infrared-transmitting member 20. The prism layer 24 includes a plurality of prism portions 26. These prism portions 26 protrude from the surface 22a of the substrate layer 22. When the direction Y of the vehicle glass 1 is defined as a first direction, these prism portions 26 are continuously formed on the surface 22a of the substrate layer 22 in the first direction, i.e., the direction Y (see FIG. 6 ). When the direction X orthogonal to the direction Y of the vehicle glass 1, i.e., the direction perpendicular to the plane of FIG. 5 , is defined as a second direction, each prism portion 26 extends along the second direction (see FIG. 6 ).

[0035] As shown in FIG. 5 , the prism portion 26 has a triangular cross section perpendicular to the direction X, and includes an inclined surface 30, which is a first surface, and a connecting surface 32, which is a second surface. The inclined surface 30 extends from the surface of the base layer 22 and is gradually inclined downward in the direction Y, which is a first direction, away from the base layer 22. The inclined surface 30 may also extend along the direction X, which is a second direction. Between adjacent prism portions 26, the connecting surface 32 connects the lower edge of the inclined surface 30 of the upper prism portion 26 and the upper edge of the inclined surface 30 of the lower prism portion 26. In other words, the connecting surface 32 connects to one inclined surface 30 and extends toward the surface of the base layer 22. In this embodiment, the connecting surface 32 is perpendicular or approximately perpendicular to the base layer 22, and the prism portion 26 has a right-angled triangular cross section. The connecting surface 32 may connect the adjacent inclined surfaces 30 so that the adjacent inclined surfaces 30 are arranged continuously when viewed from the direction of light incident on the exterior surface 20A of the infrared-transmitting member 20, for example, the direction ZV. Therefore, the connecting surface 32 does not have to be flat, and may be a surface inclined with respect to the base material layer 22.

[0036] In the prism layer 24, the average pitch P of the prism portions 26 is 1 μm or more and 25 mm or less. As shown in FIG. 5 , the pitch P of the prism portions 26 is the distance from the intersection (intersection line) between the surface 22 a and the inclined surface 30 to the intersection (intersection line) between the surface 22 a and the connecting surface 32, and corresponds to the length of the prism portions 26 in the direction Y. The inclined surface 30 of each prism portion 26 has an inclination angle θ with respect to the surface 22 a of the base layer 22, and the average inclination angle θave of the inclination angles θ of these prism portions 26 is 1 degree or more and 30 degrees or less. Furthermore, the maximum height H of each prism portion 26 from the surface 22 a of the base layer 22 is 0.01 μm or more and 4 mm or less. Note that the pitch P of the prism portions 26 does not have to be constant.

[0037] The infrared transparent member 20, which includes the base layer 22 and the prism layer 24, has a ratio Tmax / Tmin of the maximum value Tmax to the minimum value Tmin of the thickness T in a direction perpendicular to the vehicle exterior surface 20A, of 1.0 to 3.0. The infrared transparent member 20 also has an average transmittance of 50% or more for light with wavelengths of 8 μm to 12 μm. The infrared transmittance can be measured using, for example, a Fourier transform infrared spectrometer (manufactured by ThermoScientific, product name: Nicolet iS10).

[0038] As described above, the infrared transmitting member 20 including the base layer 22 and the prism layer 24 preferably contains one material selected from the group consisting of Si, ZnS, Ge, and chalcogenide glass. By using such a material for the infrared transmitting member 20, infrared rays can be transmitted appropriately.

[0039] A preferred composition of chalcogenide glass is, in atomic %, Ge + Ga; 7% to 25%, Sb; 0% to 35%, Bi; 0% to 20%, Zn; 0% to 20%, Sn; 0% to 20%, Si; 0% to 20%, La; 0% to 20%, S + Se + Te; 55% to 80%, Ti; 0.005% to 0.3%, Li + Na + K + Cs; 0% to 20%, and F + Cl + Br + I; This glass preferably has a glass transition temperature (Tg) of 140°C to 550°C. It is more preferable to use Si or ZnS as the material for the infrared-transmitting member 20.

[0040] When the material of the infrared transmitting member 20 is Si or Ge, it can be processed by grinding or cutting, and when the material of the infrared transmitting member 20 is ZnS, it can be processed by press molding using a mold. Furthermore, when the material of the infrared transmitting member 20 is chalcogenide glass, it can be processed by grinding, cutting, or press molding using a mold.

[0041] The infrared-transmitting member 20 may be formed by molding the prism layer 24 from a different material onto the base layer 22, which includes one material selected from the group consisting of Si, ZnS, Ge, and chalcogenide glass. For example, the prism layer 24 may include one or a combination of materials selected from the group consisting of Si, Ge, Si and high-density polyethylene, and Ge and high-density polyethylene. If the material for the prism layer 24 is Si and high-density polyethylene or Ge and high-density polyethylene, the prism layer 24 can be press-molded. In other words, even if the base layer 22 is made of Si or Ge, which are difficult to press-mold, the prism layer 24 can be easily processed by press molding.

[0042] 5 , the vehicle glass 1 having the infrared transmission region B having the infrared transmission member 20 and the image processing unit 8 constitute a vehicle infrared sensor device 200. Hereinafter, the vehicle infrared sensor device 200 will be simply referred to as the infrared sensor device 200.

[0043] The infrared camera CA1 installed on the vehicle interior side is disposed in a position facing the infrared transmission region B of the vehicle glass 1. As a result, the infrared camera CA1 is disposed in a position facing the prism layer 24 of the infrared transmission member 20 provided in the infrared transmission region B. The infrared sensor device 200 may or may not include the infrared camera CA1. The infrared camera CA1 may be attached to the vehicle glass 1 using an attachment or the like (not shown).

[0044] The image processing unit 8 performs image processing on an image (far-infrared image) captured by the infrared camera CA1 disposed opposite the infrared transmission area B. The image processing unit 8 detects infrared rays FA emitted from an object (subject 6) present outside the vehicle glass 1. The infrared camera CA1 captures the captured image 2 by detecting the infrared rays FA that pass through the infrared transmission area B from the outside to the inside of the vehicle glass 1.

[0045] Naturally, the infrared rays FA pass through the multiple prism portions 26 of the infrared-transmitting member 20. The infrared rays FA can take various optical paths with respect to the prism portions 26, but can also pass through the turning portions including the connection portions between the inclined surfaces 30 and the connection surfaces 32.

[0046] 7 shows an enlarged view of the prism portion 26. Infrared rays FA may take optical path P1, in which they enter the prism portion 26 from the surface 22a of the base layer 22, pass through the interior of the prism portion 26, and then directly exit from the inclined surface 30 to the outside of the infrared-transmitting member 20. However, they may also take optical path P2, which is different from optical path P1. In optical path P2, the infrared rays FA enter the prism portion 26 from the surface 22a of the base layer 22, exit from the inclined surface 30 to the outside of the infrared-transmitting member 20, then enter an adjacent prism portion 26 from its connecting surface 32 and exit from the inclined surface 30 of this prism portion 26. Here, the above-mentioned folded portion 33 is a portion of the prism portion 26 surrounded by a portion of the inclined surface 30 and a portion of the connecting surface 32, and includes a connecting portion 34 between the inclined surface 30 and the connecting surface 32. The folded portion 33 is included in part of the optical path P2, and is a portion where light incident from the connection surface 32 passes through the inside of the prism portion 26 and exits from the inclined surface 30. The connection portion 34 corresponds to one side of the triangular prism-shaped prism portion 26.

[0047] When infrared light FA passes through the folding section 33, as in the optical path P2, the infrared light FA travels in a specific direction due to the refraction of light, which may result in local variations in the density of the light beam. Furthermore, light may be concentrated at a specific pixel of the infrared camera CA1, resulting in information compression. Furthermore, if refraction or reflection occurs at the folding section 33, the light may not reach a specific pixel, resulting in information loss. Thus, the transmission of infrared light FA through the folding section 33 creates defective pixels, which are pixels in which the correct information (pixel value) contained in the light beam that would normally converge at a single pixel is partially lost, or which do not contain correct information. The portion containing these defective pixels appears as noise in the captured image 2, which may cause degradation of the captured image 2.

[0048] Therefore, the image processing unit 8 also performs processing to reduce noise that is generated in the folding unit 33 and is included in the captured image 2. As a result, the image processing unit 8 can reduce noise that is generated in the folding unit 33 of the prism unit 26 and is included in the captured image 2. The image processing unit 8 provides the captured image 2 with reduced noise to a computer (not shown), thereby reducing the possibility that the computer will mistakenly recognize that a non-existent object exists between the subject 6 and the vehicle glass 1, for example. "Noise reduction" may also mean "removal of noise from the captured image 2."

[0049] The image processing function of the image processing unit 8 is realized, for example, by a processor such as a CPU (Central Processing Unit) operating according to a program readably stored in a memory. The program that realizes the processing performed by the image processing unit 8 may be provided, for example, via a recording medium or a network.

[0050] The image processing unit 8 may be provided, for example, in an ECU (Electronic Control Unit) of the vehicle V, or in a computer outside the vehicle V. Therefore, the infrared sensor device 200 includes not only a case where the image processing unit 8 is integrated, but also a case where the image processing unit 8 is configured as a separate unit. Note that the data used for image processing may be stored in a server on a network, and the ECU of the vehicle V or a computer outside the vehicle V may perform image processing using the data in the server.

[0051] The method for reducing noise by the image processing unit 8 is not particularly limited. For example, under conditions in which the infrared sensor device 200 and the infrared camera CA1 are actually used, a target pattern is captured in advance, and an ideal image, which is an image captured without noise, is known. The captured image of the infrared FA is then acquired, and a noise pattern is obtained. The noise is generated by the refraction of the infrared FA traveling along the optical path P2 in FIG. 7 . When focusing on a specific pixel of the infrared camera CA1, the light corresponding to the noise can be divided into two types: 1) light that should have entered the specific pixel but has instead entered another pixel, and 2) light that should not have entered the specific pixel but has instead entered the specific pixel. The light in 1) above is called lost light, and the light in 2) above is called mixed light.

[0052] It is believed that lost light and mixed light occur between a specific pixel and a predetermined adjacent pixel. Therefore, by correcting for lost light and mixed light between the specific pixel and the adjacent pixel, it is possible to determine the ideal light with reduced noise that should be incident on the specific pixel, i.e., the correct pixel value.

[0053] FIG. 8 shows a matrix of pixels consisting of 3 rows and 3 columns for performing image restoration processing. ｉ，ｊ is a number that identifies a pixel and also indicates a pixel value (for example, a far-infrared luminance value) corresponding to the amount of light of the pixel. ２，２ In this case, the specific pixel I ２，２ is a predetermined mixture ratio a between each of the eight adjacent pixels. ｉ，ｊ It can be assumed that lost light and mixed light are exchanged under the

[0054] As an example of a noise reduction method, distortion map data can be used. The distortion map data is measured by acquiring photographed images of nine types of 3-row, 3-column tiling patterns in advance under conditions in which the infrared sensor device 200 and the infrared camera CA1 are actually used, and comparing them with an ideal image without noise to determine the mixing ratio a ｉ，ｊ Calculate the mixture ratio a i，j is also referred to as distortion data. ｉ，ｊ The specific pixel I ２，２The pixel value v (for example, far-infrared luminance value) of is expressed by the following equation (1).

[0055]

[0056] The pixel value v is originally a specific pixel I ２，２ The pixel value of the light beam converging on the specific pixel I is the sum of the results of the lost light and mixed light exchanged with each of the eight adjacent pixels. ２，２ By acquiring a photographed image of a tiling pattern in which only the pixel I has a brightness value of 100 and the other 8 pixels have a brightness value of 0, i，j to a specific pixel I ２，２ Mixing ratio of light to i，j For the other 8 pixels, the photographed images of the tiling pattern corresponding to the position of each pixel are acquired and processed in the same way, and each mixture ratio a ｉ，ｊ Measure the mixture ratio a ｉ，ｊ The distortion map data is correction mask data that includes the positions and mixing ratios of defective pixels.

[0057] The missing area of ​​the captured artifact image contains pixel values ​​of the above mixture ratio, and the distortion map data is used to calculate the pixel value of each pixel I ｉ，ｊ The original image can be restored by inversely calculating the ideal pixel values ​​for the image. The image of the subject captured by the infrared camera CA1 is an artifact image containing noise caused by the mixing of light rays at the folding section 33 of the prism section 26. The image processing section 8 performs processing on the artifact image to restore missing pixels using the distortion map data, thereby obtaining a corrected image with reduced noise. The corrected image is sent to a downstream computer and used for image recognition processing, etc.

[0058] In this example, a pixel matrix consisting of 3 rows and 3 columns is used, but the size of the matrix may be changed in consideration of the possibility that light may be exchanged with pixels over a wider range, etc. For example, if the size of the matrix is ​​changed to a pixel matrix consisting of 5 rows and 5 columns, a pixel matrix consisting of 7 rows and 7 columns, etc., the "3" in formula (1) will change according to the number of pixels in the matrix.

[0059] For example, when the vehicle V is shipped, the mixture ratio a ｉ，ｊ The image processing unit 8 may generate distortion map data, which is a collection of the above-mentioned distortions, and store the data in advance in a predetermined memory or the like inside or outside the vehicle V. When the vehicle V and the infrared sensor device 200 are in operation, the image processing unit 8 converts the captured image taken by the infrared camera CA1 into the distortion map data based on the mixture ratio a stored in the memory or the like. ｉ，ｊ By performing correction using distortion map data including the above, it is possible to reduce noise that may be contained in the captured image.

[0060] Whether or not noise contained in a captured image is noise generated in the folding portion 33 of the prism portion 26 can be determined from the shape of the generated noise. For example, in an artifact image, which is a captured image in which light rays pass through the prism portion 26 and noise generated by the folding portion 33 is mixed, streaky noise appears according to the arrangement direction and spacing of the prism portions 26. The position and size of the noise in the captured image are constant depending on the relative positional relationship between the infrared-transmitting member 20 and the infrared camera CA1 and the lens focal length of the infrared camera, and therefore this noise can be corrected using the distortion map data described above.

[0061] Next, let us consider the relationship between the direction in which the folded portions 33 or connecting portions 34 of the prism portion 26, which cause noise, are formed and the pixel array direction of the infrared camera CA1. Figure 9 is a schematic diagram showing the arrangement of a defective region including a defective pixel when the connecting portions 34 and folded portions 33 of the prism portion 26 extend parallel to one of the pixel array directions of the infrared camera CA1. The connecting portions 34 and folded portions 33 extend parallel to the horizontal direction, which is one of the pixel array directions in which the pixels are arranged.

[0062] In such a state, defective areas including defective pixels appear unevenly and continuously in the horizontal direction. In the example shown in FIG. 9, noise contained in the captured image can be reduced by restoring the defective pixels using the distortion map data described above. However, in the example of FIG. 9, since many defective pixels are included in the horizontal direction, the mixture ratio a ｉ，ｊ In the restoration process using the above, the restoration accuracy may be directionally dependent, that is, it may be difficult to perform correction using adjacent pixels in the horizontal direction.

[0063] 10 is a schematic diagram showing the arrangement of the defective region in a state where the connection portion 34 and the folded portion 33 extend in a specific direction that is not parallel to the pixel array direction but intersects with the pixel array direction. That is, in the example shown in FIG. 10, the infrared transparent member 20 is configured in a state where the prism portion 26 is tilted so that the pixel array direction and the array direction of the prism portion 26 do not coincide with each other. In this state, unlike FIG. 9, the defective pixels are not concentrated in a specific direction such as the horizontal direction. Therefore, the mixture ratio a for the specific pixel ｉ，ｊ In the restoration process using the above, adjacent pixels in the vertical direction of a specific pixel can also be used, so that the directional dependency of restoration accuracy can be improved, and the image processing unit 8 can accurately reduce noise.

[0064] 10, the connecting portion 34 and the folded portion 33 may extend at an angle of 45 degrees with respect to the pixel array direction. Since the defective region is not concentrated in pixels in a specific direction, the directional dependency of the restoration accuracy can be improved.

[0065] 10, the connection portion 34 and the folded portion 33 may extend in the diagonal direction of the pixel array area of ​​the infrared camera CA1. Since the missing area is not concentrated on pixels in a specific direction, the directional dependency of the restoration accuracy can be improved.

[0066] The image processing unit 8 can restore missing pixels included in the captured image using the distortion map data described above. This allows the missing pixels to be restored appropriately because distortion map data indicating the light mixing ratio for multiple pixels adjacent to a specific pixel is used.

[0067] As described above, the prism portions 26 extend along the direction X (second direction) perpendicular to the direction Y (first direction), and the average pitch of the prism portions 26 is 1 μm or more and 25 mm or less, thereby enabling infrared detection with a sufficient field of view without unnecessarily expanding the infrared transmission area while maintaining good contrast.

[0068] 11 shows a modified example of the prism unit 26. The inclination angle θ of the inclined surface 30 of the prism unit 26 may be configured to decrease as it approaches the reference position SP corresponding to the center of the optical axis of the infrared camera CA1. This reduces the frequency with which the infrared FA takes the optical path P2 shown in FIG. 7, reduces the presence of the folding unit 33 itself, and reduces noise.

[0069] The prism portion 26 is not limited to the configuration of this embodiment, but may be formed by a so-called Fresnel convex lens or the like, and depending on the structure, the direction X (second direction) and the direction Y (first direction) are not necessarily perpendicular to each other.

[0070] As shown in Fig. 5, the infrared camera CA1 is installed with its optical axis AX tilted upward relative to the horizontal ZV direction toward the vehicle glass 1. That is, the infrared camera CA1 is installed so that the optical axis AX faces upward at a flap angle φ relative to the horizontal direction. The flap angle φ of the optical axis AX of this infrared camera CA1 with respect to the vehicle glass 1 is set to 1 degree or more. In this way, in the infrared sensor device 200, by installing the infrared camera CA1 so that the optical axis AX faces upward relative to the horizontal direction toward the vehicle glass 1 at a flap angle φ of 1 degree or more, the field of view of the infrared camera CA1 through the infrared transmission region B can be increased.

[0071] Fig. 12 is a schematic diagram showing the relationship between the orientation and field of view of the infrared camera CA1, and Fig. 13 is a schematic diagram showing the relationship between the placement and field of view of the infrared camera CA1. As shown in Fig. 12, when the infrared camera CA1 is installed horizontally with respect to the vehicle glass 1 tilted toward the rear of the vehicle (see orientation Pa on the right side of Fig. 12), the vertical field of view of the infrared camera CA1 through the infrared transmission region B is narrowed (see field of view Fa shown by the dotted line on the left side of Fig. 12). In contrast, when the infrared camera CA1 is installed tilted upward at a flap angle φ with respect to the vehicle glass 1 tilted toward the rear of the vehicle (see orientation Pb on the right side of Fig. 12), the vertical field of view of the infrared camera CA1 through the infrared transmission region B can be enlarged (see field of view Fb shown by the solid line on the left side of Fig. 12). Furthermore, by tilting the infrared camera CA1 upward, the distance between the camera lens and the infrared transmission region B can be reduced, as shown in Fig. 13. When the distance between the camera lens and the infrared-transmitting region B is reduced (see position Pc on the right side of Figure 13), the field of view of the infrared camera CA1 through the infrared-transmitting region B can be enlarged not only in the vertical direction but also overall (see field of view Fc on the left side of Figure 13).

[0072] If the infrared-transmitting member 20 is flat, it will be difficult for the infrared camera CA1 tilted upward relative to the vehicle glass 1 to capture infrared rays from the front of the vehicle. In this case, if the infrared-transmitting member 20 has a prism shape in which the overall thickness decreases toward the top of the vehicle, the direction of the infrared rays from the front of the vehicle that pass through the infrared-transmitting member 20 can be guided to the infrared camera CA1. However, a large difference in optical path occurs between the upper and lower positions of the infrared-transmitting member 20, and a decrease in contrast due to the difference in absorption loss is unavoidable.

[0073] In the infrared sensor device 200 configured as described above, the infrared transparent member 20 is provided on the interior surface 22a of the base material layer 22 with a prism layer 24 having a plurality of prism portions 26 with an average pitch of 1 μm or more and 25 mm or less. The inclined surfaces 30 of these plurality of prism portions 26 change the optical paths of the respective prism portions 26. This reduces the difference in the optical paths of the infrared rays transmitted between the upper and lower positions of the infrared transparent member 20, thereby suppressing a decrease in contrast due to differences in absorption loss. In other words, the infrared sensor device 200 can detect infrared rays with a sufficient field of view while maintaining good contrast and without unnecessarily expanding the infrared transparent region B.

[0074] 5, the infrared camera CA1 is installed so that the distance D between the outermost position S centered on the optical axis AX and the infrared transparent member 20 is 1 mm or more and 30 mm or less. This allows the field of view of the infrared camera CA1 to be expanded overall, i.e., in the left-right direction as well as the up-down direction, as described above. Furthermore, the infrared transparent member 20 has an outer diameter that is larger than the outer diameter of the lens of the infrared camera CA1 by 1 mm or more and 30 mm or less. This allows the infrared camera CA1 to secure a larger field of view while minimizing the size of the infrared transparent region B.

[0075] In the prism layer 24 of the infrared transparent member 20, the inclination angle θ of the inclined surface 30 of each prism portion 26 is not limited to being constant and may be different from one another. For example, the inclination angle θ of the inclined surface 30 of the prism portion 26 may be varied so as to gradually increase or decrease downward in the first direction (direction Y). Furthermore, the inclination angle θ of the inclined surface 30 of the prism portion 26 may be varied so as to gradually increase from the center toward the outside (vertical direction) in the first direction (direction Y). In this way, the optical path of infrared light passing through the infrared transparent member 20 can be adjusted according to position. Furthermore, as another example of the prism layer 24 of the infrared transparent member 20, as shown in FIGS. 14 and 15 , the inclined surface 30 of the prism portion 26 may be inclined in the first direction (direction Y) so as to move away from the base layer 22 as it moves from the center toward the vertical direction. This allows for a wider field of view.

[0076] 16 is a schematic cross-sectional view of a modified infrared ray transmitting member 20. In the modified example shown in Fig. 16, the infrared ray transmitting member 20 has an anti-reflection layer 36 on the vehicle interior side. The anti-reflection layer 36 is provided on the inclined surface 30 of each prism portion 26 constituting the prism layer 24 of the infrared ray transmitting member 20.

[0077] The anti-reflection layer 36 is made of ZrO ２ , NiO ｘ , ZnS, Ge, Si, MgO, ZnO, and Bi ２ O ３ It is preferable that the anti-reflection layer 36 contains one or more selected from the group consisting of ZrO ２ , NiO ｘ It is more preferable to use at least one of MgO and MgO.

[0078] The anti-reflection layer 36 is made of NiO. ｘ When the antireflection layer 36 contains NiO as a main component, the term "main component" here may mean that the content of NiO in the entire antireflection layer 36 is 50 mass % or more. ｘ The content of NiO in the entire antireflection layer 36 is 50% by mass or more and 100% by mass or less, preferably 70% by mass or more and 100% by mass or less, and more preferably 90% by mass or more and 100% by mass or less. ｘ Elemental, i.e., excluding unavoidable impurities, NiO ｘ The anti-reflection layer 36 preferably contains NiO. ｘ When the content falls within this range, reflection of infrared rays can be suppressed and infrared rays can be transmitted appropriately.

[0079] It is known that nickel oxide can take on a variety of compositions depending on the valence of nickel, and x can take any value from 0.5 to 2. The valence does not have to be single, and two or more types of valences may be mixed.

[0080] The thickness of the antireflection layer 36 is preferably 1000 nm or more and 2000 nm or less, more preferably 1000 nm or more and 1500 nm or less, and even more preferably 1100 nm or more and 1300 nm or less. When the thickness of the antireflection layer 36 is within this range, reflection of infrared rays is suppressed and infrared rays can be appropriately transmitted. The thickness of the antireflection layer 36 can also be said to be the length in the Z direction from the surface of the antireflection layer 36 on the Z direction side to the surface opposite the Z direction.

[0081] The antireflection layer 36 is capable of transmitting infrared rays. The antireflection layer 36 preferably has an extinction coefficient for light with a wavelength of 10 μm of 0.05 or less, more preferably 0.03 or less, even more preferably 0.02 or less, and most preferably 0.01 or less. An extinction coefficient within this range allows appropriate transmission of infrared rays.

[0082] The anti-reflection layer 36 preferably has an extinction coefficient for light with a wavelength of 550 nm (visible light) of 0.04 or more, more preferably 0.06 or more, even more preferably 0.08 or more, and most preferably 0.10 or more. When the extinction coefficient for visible light of the anti-reflection layer 36 falls within this numerical range, the reflectance dispersion of visible light can be appropriately suppressed, and an appearance that ensures designability can be achieved.

[0083] The anti-reflection layer 36 may be provided on the connecting surface 32 in addition to the inclined surface 30 of each prism portion 26. The anti-reflection layer 36 may be provided not only on the interior side of the infrared-transmitting member 20 but also on the exterior side surface 20A, or may be provided on both the interior and exterior sides of the infrared-transmitting member 20.

[0084] Furthermore, when the base material layer 22 and the prism layer 24 are formed from different materials, the anti-reflection layer 36 may be provided on the surface 22a, which is the connecting surface between the base material layer 22 and the prism layer 24. Furthermore, the anti-reflection layer 36 is not limited to being provided on the surface 22a, but may also be provided on the inclined surface 30, which is the surface on the vehicle interior side of the infrared transparent member 20, or on the surface 20A on the vehicle exterior side, or may also be provided on the surface 22a, the surface on the vehicle interior side (inclined surface 30) of the infrared transparent member 20, and the surface 20A on the vehicle exterior side.

[0085] An outermost layer may be provided on at least one of the inside and outside surfaces of the infrared-transmitting member 20. This outermost layer may be made of, for example, ZrO ２ , and DLC (diamond-like carbon), and the thickness is preferably 50 nm or more and 500 nm or less. The thickness of the outermost layer is preferably 80 nm or more, and more preferably 100 nm or more. Furthermore, as an optical property of the outermost layer, the extinction coefficient k at a wavelength of 10 μm is preferably 0.2 or less. By providing the outermost layer, the infrared transparent member 20 can be protected from scratches caused by wiping with a wiper or dust, corrosion caused by oil or chemicals, etc.

[0086] When the anti-reflection layer 36 is provided, an intermediate layer may be provided between the anti-reflection layer 36 and the infrared-transmitting member 20 as an adhesive layer for adhering the anti-reflection layer 36 to the infrared-transmitting member 20. The intermediate layer may be, for example, ZrO ｘ , TiO ｘ , SiN ｘ , ZnO ｘ , TaO ｘ , NbO ｘ , SnO ｘ , AlO ｘ The thickness of the intermediate layer is preferably 5 nm to 30 nm. As for optical properties of the intermediate layer, the extinction coefficient k at a wavelength of 10 μm is preferably 0.3 or less.

[0087] When a laminate consisting of the anti-reflection layer 36, the outermost layer, and the intermediate layer is provided, the thickness of this laminate is preferably 1000 nm or more and less than 5000 nm. Furthermore, as an optical characteristic of the laminate, it is preferable that the average transmittance at a wavelength of 8 μm to 12 μm is 50% or more.

[0088] As such, the present invention is not limited to the above-described embodiments, and the present invention also contemplates the mutual combination of the various components of the embodiments, as well as modifications and applications by those skilled in the art based on the description in the specification and well-known techniques, and these modifications and applications are included in the scope of protection sought.

[0089] As described above, this specification discloses the following: (1) A vehicle infrared sensor device (infrared sensor device 200) including: a vehicle glass (1) having a light-shielding area (A2) provided with an infrared-transmitting area (B) in which an infrared-transmitting member (20) is arranged within an opening (19); and an image processing unit (8) that performs image processing on an image (2) captured by an infrared camera (CA1) that is arranged opposite the infrared-transmitting area, wherein the infrared-transmitting member has: a base layer (22); and a prism layer (24) having a plurality of prism portions (26) formed continuously in a first direction (direction Y) on a surface of the base layer, the prism portions having a first surface (inclined surface 30) extending from a surface (22a) of the base layer and gradually inclining in a direction away from the base layer toward one side of the first direction, and a second surface (connecting surface 32) connected to the first surface and extending toward the surface of the base layer, and a second surface of the prism portion of the infrared sensor device for a vehicle, the ...

[0090] (2) The vehicle infrared sensor device according to (1), wherein the folding portion extends in a specific direction intersecting with a pixel array direction of the infrared camera, and the image processing unit reduces the noise by restoring a defective pixel included in the captured image using information on pixels adjacent to the defective pixel. With this vehicle infrared sensor device, the defective area is not biased in a specific direction, thereby improving the directional dependency of restoration accuracy.

[0091] (3) The vehicle infrared sensor device according to (2), wherein the folded portion extends so as to be inclined at 45 degrees with respect to the pixel array direction. With this vehicle infrared sensor device, the defective region is not biased in a specific direction, so that the directional dependency of the restoration accuracy can be improved.

[0092] (4) The vehicle infrared sensor device according to (2), wherein the folded portion extends in a diagonal direction of a pixel array area of ​​the infrared camera. With this vehicle infrared sensor device, the missing area is not biased in a specific direction, thereby improving the directional dependency of restoration accuracy.

[0093] (5) The vehicle infrared sensor device according to any one of (1) to (4), wherein the image processing unit restores missing pixels included in the captured image by using distortion map data. This vehicle infrared sensor device can appropriately restore missing pixels by using calibration data that indicates a mixing ratio of light to a plurality of pixels adjacent to a specific pixel.

[0094] (6) The vehicle infrared sensor device according to any one of (1) to (5), wherein the prism portions extend along a second direction (X direction) perpendicular to the first direction, and an average pitch of the prism portions is 1 μm or more and 25 mm or less. This vehicle infrared sensor device can detect infrared rays with a sufficient field of view while maintaining good contrast and without unnecessarily expanding the infrared transmission area.

[0095] (7) The vehicle infrared sensor device according to any one of (1) to (6), wherein the inclination angle of the first surface of the prism portion decreases as the prism portion approaches a reference position corresponding to the center of the optical axis of the infrared camera. With this vehicle infrared sensor device, the presence of the folded portion itself can be reduced, thereby reducing noise.

[0096] (8) The vehicle infrared sensor device according to any one of (1) to (7), wherein the average inclination angle of the first surface of the prism portion is 1 degree or more and 30 degrees or less, and the maximum height of the prism portion is 0.01 μm or more and 4 mm or less. With this vehicle infrared sensor device, it is possible to suppress a decrease in contrast caused by a transmittance difference.

[0097] (9) The vehicle infrared sensor device according to any one of (1) to (8), wherein the infrared transmitting member includes one material selected from the group consisting of Si, ZnS, Ge, and chalcogenide glass. According to this vehicle infrared sensor device, an infrared transmitting member with good transmittance can be formed by various processing methods.

[0098] (10) The vehicle infrared sensor device according to any one of (1) to (9), wherein the infrared transparent member has an average transmittance of 50% or more for light having a wavelength of 8 μm to 12 μm. This vehicle infrared sensor device can appropriately function as an infrared transparent member.

[0099] (11) The vehicle infrared sensor device according to any one of (1) to (10), wherein the infrared transparent member has a ratio Tmax / Tmin of a maximum value Tmax to a minimum value Tmin of a thickness T in a direction perpendicular to the surface of the infrared transparent member, which is 1.0 to 3.0. This vehicle infrared sensor device can appropriately exhibit the function of the infrared transparent member.

[0100] (12) The infrared transmitting member has an anti-reflection layer, and the anti-reflection layer is made of ZrO ２ , NiO ｘ , ZnS, Ge, Si, MgO, ZnO, and Bi ２ O ３ The vehicle infrared sensor device according to any one of (1) to (11), comprising one or more selected from the group consisting of: This vehicle infrared sensor device can improve scratch resistance while allowing infrared rays to pass through appropriately.

[0101] (13) The vehicle infrared sensor device according to any one of (1) to (12), wherein the prism layer has a plurality of the prism portions each having a different inclination angle of the first surface. With this vehicle infrared sensor device, the optical path of the transmitted infrared light can be adjusted depending on the position.

[0102] (14) The vehicle infrared sensor device according to any one of (1) to (13), wherein the prism portion has a cross section along the first direction that is a right-angled triangle. With this vehicle infrared sensor device, the infrared transmitting member can be easily manufactured.

[0103] (15) An image processing method comprising: capturing an image using an infrared camera that detects infrared rays passing through an infrared transmitting region; the infrared transmitting region being an infrared transmitting member disposed in an opening provided in a light-shielding region of a vehicle glass; the infrared transmitting member having a base layer and a prism layer having a plurality of prism portions continuously formed in a first direction on a surface of the base layer; the prism portions having a first surface extending from the surface of the base layer and gradually inclining away from the base layer toward one side of the first direction; a second surface connected to the first surface and extending toward the surface of the base layer; and a folding portion including a connecting portion between the first surface and the second surface; and reducing noise generated at the folding portion and included in the captured image. This image processing method reduces noise generated at the folding portion of the prism portion and included in the captured image through the infrared transmitting region, thereby suppressing deterioration in quality of the captured image.

[0104] This application is based on a Japanese patent application filed on September 13, 2023 (Patent Application No. 2023-148446) and a Japanese patent application filed on November 22, 2023 (Patent Application No. 2023-198272), the contents of which are incorporated by reference into this application.

[0105] REFERENCE SIGNS LIST 1 Vehicle glass 2 Captured image 8 Image processing unit 19 Opening 20 Infrared-transmitting member 22 Base material layer 22a Surface 24 Prism layer 26 Prism portion 30 Inclined surface (first surface) 32 Connection surface (second surface) 33 Turned portion 34 Connection portion 36 Anti-reflection layer 200 Vehicle infrared sensor device A2 Light-shielding area AX Optical axis B Infrared-transmitting area CA1 Infrared camera P Pitch θ Tilt angle φ Swing angle

Claims

1. A vehicle infrared sensor device comprising: a vehicle glass having a light-shielding area in which an infrared-transmitting area is provided with an infrared-transmitting material disposed within an opening; and an image processing unit that performs image processing on an image captured by an infrared camera disposed opposite the infrared-transmitting area, wherein the infrared-transmitting material has: a base layer; and a prism layer having a plurality of prism portions formed continuously in a first direction on a surface of the base layer, each prism portion having a first surface extending from the surface of the base layer and gradually inclining away from the base layer towards one side of the first direction, a second surface connected to the first surface and extending towards the surface side of the base layer, and a folded portion including a connection portion between the first surface and the second surface, and the image processing unit reduces noise generated at the folded portion and included in the captured image.

2. The vehicle infrared sensor device of claim 1, wherein the folding portion extends in a specific direction intersecting with the pixel array direction of the infrared camera, and the image processing portion reduces the noise by restoring defective pixels included in the captured image using information on pixels adjacent to the defective pixels.

3. The vehicle infrared sensor device according to claim 2, wherein the folded portion extends so as to be inclined at 45 degrees with respect to the pixel array direction.

4. The vehicle infrared sensor device according to claim 2, wherein the folded portion extends in a diagonal direction of a pixel array area of ​​the infrared camera.

5. The vehicle infrared sensor device according to claim 1, wherein the image processing unit uses distortion map data to restore defective pixels contained in the captured image.

6. The vehicle infrared sensor device according to claim 1, wherein the prism portions extend along a second direction perpendicular to the first direction, and an average pitch of the prism portions is not less than 1 μm and not more than 25 mm.

7. The vehicle infrared sensor device according to claim 1, wherein the inclination angle of the first surface of the prism portion decreases as the inclination angle approaches a reference position corresponding to the center of the optical axis of the infrared camera.

8. The vehicle infrared sensor device according to claim 1, wherein an average inclination angle of the first surface of the prism portion is equal to or greater than 1 degree and equal to or less than 30 degrees, and a maximum height of the prism portion is equal to or greater than 0.01 μm and equal to or less than 4 mm.

9. The vehicle infrared sensor device according to claim 1, wherein the infrared transmitting member contains one material selected from the group consisting of Si, ZnS, Ge, and chalcogenide glass.

10. The vehicle infrared sensor device according to claim 1, wherein the infrared transparent member has an average transmittance of 50% or more for light with a wavelength of 8 μm to 12 μm.

11. The vehicle infrared sensor device according to claim 1, wherein the infrared transparent member has a thickness T in a direction perpendicular to the surface, the ratio Tmax / Tmin of the maximum value Tmax to the minimum value Tmin being 1.0 to 3.

0.

12. The infrared ray transmitting member has an anti-reflection layer, and the anti-reflection layer is made of ZrO ２ , NiO ｘ , ZnS, Ge, Si, MgO, ZnO, and Bi ２ O ３ The vehicle infrared sensor device according to claim 1 , comprising at least one selected from the group consisting of:

13. The vehicle infrared sensor device according to claim 1, wherein the prism layer has a plurality of the prism portions, the first surfaces of which have different inclination angles.

14. The vehicle infrared sensor device according to any one of claims 1 to 13, wherein a cross section of the prism portion along the first direction is in the shape of a right triangle.

15. An image processing method comprising: capturing an image using an infrared camera that detects infrared rays passing through an infrared-transmitting area; the infrared-transmitting area being an infrared-transmitting member disposed in an opening provided in a light-shielding area of ​​vehicle glass; the infrared-transmitting member having a base layer and a prism layer having a plurality of prism portions formed continuously in a first direction on a surface of the base layer; the prism portions having a first surface extending from the surface of the base layer and gradually inclining away from the base layer towards one side of the first direction; a second surface connected to the first surface and extending towards the surface side of the base layer; and a folded portion including a connection portion between the first surface and the second surface; and reducing noise generated in the folded portion and included in the captured image.

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