Imaging device and window glass equipped with imaging device

Abstract

Provided are an imaging device capable of capturing an image of the outdoor side without using a lens hood even when indoor illumination is on at night-time, and a window glass equipped with the imaging device.　This imaging device comprises: a housing having a surface configured to face a main surface on the indoor side of a window glass of a building; a lens provided in an opening of the surface of the housing and facing the main surface; and an imaging part provided in the housing and configured to be able to capture an image of the outdoor side of the window glass via the lens. The imaging lens has an angle of view of 40 degrees or more, and the distance in a direction parallel to the main surface between the lens and the building that is in contact with the window glass is 0-180 mm.

Description

Imaging device and window glass with imaging device

[0001] The present disclosure relates to an imaging device and a window glass equipped with an imaging device.

[0002] A conventional window camera includes an imaging unit that captures an outdoor image from the indoor surface of a window glass, a housing having a rectangular mounting surface facing the indoor surface and recessing the imaging unit into the mounting surface with the optical axis of the imaging unit aligned with the intersection of a pair of diagonal lines of the mounting surface, and a light-blocking member made of an elastic material, protruding from the mounting surface toward the indoor surface and formed in a rectangular frame shape that conforms to the outer shape of the mounting surface, and elastically deforming when pressed by the housing to close the gap between the indoor surface and the mounting surface. This window camera is fixed to the indoor surface of the window glass by a suction cup member of a suction cup suction mechanism of the housing. The suction cup member is made of an elastic material (see, for example, Patent Document 1 below).

[0003] Japanese Patent Application Laid-Open No. 2021-111812

[0004] However, when capturing an image of the outdoors from the indoor side of a window at night, the indoor image is reflected by the window glass, creating a reflected image that overlaps with the outdoor image, making it difficult to see the outdoor image. This phenomenon is particularly noticeable when the indoor lights are on or when a heat-reflecting film such as a Low-E (low emissivity) film is formed on the window glass.

[0005] One way to reduce this kind of reflection is to attach a lens hood to the window camera. However, because the lens hood protrudes toward the window glass and expands in the direction of increasing diameter, it becomes difficult to install the window camera close to structures such as a sash (window frame) or pillar. Furthermore, the presence of the lens hood makes the window camera larger when viewed from outside, making it more noticeable, making it unsuitable for use in security surveillance, for example.

[0006] Therefore, an object of the present invention is to provide an imaging device that can capture an image of the outdoor side even when indoor lighting is on at night without using a lens hood, and a window glass with an imaging device.

[0007] An imaging device according to an embodiment of the present disclosure includes a housing having a surface configured to face the indoor main surface of a window glass of a building, a lens provided in an opening in the surface of the housing and configured to face the main surface, and an imaging unit provided within the housing and configured to be able to image the outdoor side of the window glass through the lens, the imaging device having an angle of view of 40 degrees or more, and the distance between the lens and a structure in contact with the window glass in a direction parallel to the main surface being 0 mm or more and 180 mm or less.

[0008] To provide an imaging device capable of capturing an outdoor image even when indoor lighting is on at night without using a lens hood, and a window glass with an imaging device.

[0009] 5A to 5F are diagrams illustrating an example of the arrangement of an imaging device. 1A is an enlarged view illustrating an example of the configuration of the imaging device and its surroundings. 2B is a diagram illustrating an example of the configuration of an imaging device. 3A is a diagram illustrating an example of the configuration of an imaging device. 4A is a diagram illustrating an example of the configuration of an imaging device. 5B is a diagram illustrating an example of the configuration of a cross section taken along the IIC-IIC arrows in FIG. 2B. 6A is a diagram illustrating an example of the reason why a reflected image is included in an image captured by a comparative imaging device. 7A is a diagram illustrating an example of the reason why a reflected image is included in an image captured by a comparative imaging device. 8A is a diagram illustrating an example of the reason why an imaging device according to an embodiment can reduce the reflected image. 9A is a diagram illustrating an example of the reason why an imaging device according to an embodiment can reduce the reflected image. 10A to 12A are diagrams illustrating an example of the image obtained by capturing fixed-point images with a camera, with the horizontal angle of view θx set to 40 degrees, 50 degrees, 70 degrees, 80 degrees, 105 degrees, and 120 degrees. 11A to 12A are diagrams illustrating an example of the simulation results calculated for the reflection reduction rate Rx (%) relative to the distance Dx, with the horizontal angle of view θx set to 40 degrees to 100 degrees in 10-degree increments. Fig. 5C is a diagram illustrating an example of a calculation result when the horizontal angle of view θx shown in Fig. 5B is 40 degrees. Fig. 6 is a diagram illustrating an example of a glare reduction rate Rx with respect to a distance Dx in the imaging apparatus of the embodiment.

[0010] Hereinafter, embodiments of the imaging device and window glass with an imaging device according to the present disclosure will be described. In the following, the same elements will be denoted by the same reference numerals, and duplicated descriptions may be omitted.

[0011] In the following description, for ease of understanding, the scale of each component in the drawings may differ from the actual scale. In this embodiment, a three-dimensional Cartesian coordinate system with three axes (X-axis, Y-axis, and Z-axis) is used. For example, the width (horizontal) direction of the windowpane is the X-axis, the height (height) direction of the windowpane is the Y-axis, and the thickness (thickness) direction of the windowpane is the Z-axis. In the width direction of the windowpane, the direction toward the mounting position of the imaging device on the windowpane is the +X-axis, and the opposite direction is the -X-axis. In the width direction of the windowpane, the direction from bottom to top of the windowpane is the +Y-axis, and the opposite direction is the -Y-axis. In the following description, the +Z-axis direction may be referred to as "up" and the -Z-axis direction may be referred to as "down." Planar view refers to a view from the XY plane. For example, the X-axis and Z-axis directions are approximately parallel to a horizontal plane (horizontal direction), and the Y-axis direction is approximately parallel to a vertical direction perpendicular to the horizontal plane.

[0012] The X-axis, Y-axis, and Z-axis directions represent directions parallel to the X-axis, Y-axis, and Z-axis, respectively. The X-axis, Y-axis, and Z-axis directions are perpendicular to one another. The XY plane, YZ plane, and ZX plane represent imaginary planes parallel to the X-axis and Y-axis directions, imaginary planes parallel to the Y-axis and Z-axis directions, and imaginary planes parallel to the Z-axis and X-axis directions, respectively.

[0013] 1A is a diagram showing an example of the arrangement of an imaging device 100 according to the present disclosure as viewed from the outside of a building 1. Fig. 1B is an enlarged view of an example of the imaging device 100 and its surrounding configuration in Fig. 1A. Figs. 1A and 1B also show a window 10 provided in a wall 1W of the building 1. The building 1 is an example of a structure.

[0014] The window 10 has a window glass 11 and a window frame 12. The window frame 12 is an example of a structure that contacts the window glass 11. The window frame 12 may be in direct contact with the window glass 11, or indirect contact via a member or the like. The window glass 11 is, for example, a fixed window, but may also be a sliding window or the like. FIG. 1B shows a portion of the window glass 11 and the window frame 12. Below, as an example, a configuration in which the window frame 12 is made of a magnetic metal will be described.

[0015] The imaging device 100 is installed and used so as to face the indoor-side main surface 11B2 (see FIG. 1B ) of the window glass 11 provided in the window 10 of the building 1. As an example, the imaging device 100 is a box-shaped device that is triangular in plan view, and is placed at the corners on the +X-axis direction and +Y-axis direction sides of the window glass 11 and window frame 12.

[0016] Here, the window glass 11, the window frame 12, and the imaging device 100 constitute the window glass with imaging device 200 of the embodiment. However, the window glass with imaging device 200 may be configured to include the window glass 11 and the imaging device 100 but not include the window frame 12.

[0017] The imaging device 100 is a device that captures an outdoor image through a window glass 11, and is connected, for example, via a cable 101 (see FIG. 1B ) to a processing device that performs image processing, etc. The imaging device 100 transmits image data to the processing device via the cable 101. The imaging device 100 also receives, via the cable 101, a control signal from the processing device that switches the imaging unit 140 on / off, etc., and is supplied with power from the processing device.

[0018] The processing device is located inside the building 1, but is not shown in Figures 1A and 1B. For example, the processing device may be connected to an information processing device such as an outdoor server via a wireless communication device or cable provided inside the building 1. Furthermore, for example, the processing device may be connected to an information processing device such as a personal computer (PC) or server provided inside the building 1 via a cable or wireless communication device, and the PC or server may be connected to an outdoor higher-level server or the like via a cable or wireless communication device.

[0019] Here, a form in which the window glass 11 is attached to the building 1 will be described, but the window glass 11 may also be attached to a structure other than the building 1. The structure other than the building 1 may be, for example, a civil engineering structure such as a bridge pier, a bridge, or a dam, a historical structure, an artistic structure, or the like.

[0020] The window glass 11 is a glass plate used in a window of a structure such as the building 1. The window glass 11 may be a glass facade at the entrance of the building 1, for example. The window glass 11 is formed, for example, in a rectangular shape in a plan view, and has an outer surface of the building 1 and an inner surface of the building 1. The inner surface of the building 1 refers to the indoor side of the building 1. The thickness of the window glass 11 is set according to the specifications of the building 1. Note that the term "rectangular" means a rectangular or square shape, as well as a rectangular or square shape with chamfered corners. The shape of the window glass in a plan view is not limited to a rectangular shape, and may be another shape such as a circular shape.

[0021] For example, the window glass 11 is a single-pane glass having an outdoor main surface 11A1 and an indoor main surface 11B2. The window glass 11 is not limited to a single-pane glass, and may be laminated glass or double-glazed glass. The window glass 11 may also be Low-E (low emissivity) glass or light-control glass.

[0022] Examples of materials for the window glass 11 include soda lime silica glass, borosilicate glass, aluminosilicate glass, and alkali-free glass.

[0023] The thickness of the window glass 11 is preferably 1.0 to 20 mm. If the thickness of the window glass 11 is 1.0 mm or more, the window 10 has sufficient strength for attaching the imaging device 100. Furthermore, if the thickness of the window glass 11 is 20 mm or less, the window 10 has sufficient radio wave transmission performance for the wireless communication device to stably connect via wireless communication to an information processing device such as an outdoor server. The thickness of the window glass is more preferably 3.0 to 15 mm, and even more preferably 9.0 to 13 mm.

[0024] The window glass 11 has a visible light reflectance of 6% or more as specified in JIS R 3106:2019. The window glass 11 has a visible light transmittance (TV) of 30% to 96% as specified in JIS R 3106:2019. If the TV of the window glass 11 is 30% or more, sufficient image quality is achieved when the imaging device 100 captures an outdoor image through the window glass 11. If the TV of the window glass 11 is 98% or less, excellent solar radiation shielding is achieved. The TV of the window glass 11 is preferably 50% or more, more preferably 70% or more, even more preferably 75% or more, and particularly preferably 80% or more. The TV of the window glass 11 is preferably 95% or less, more preferably 92% or less, even more preferably 90% or less, and particularly preferably 85% or less.

[0025] The imaging device 100 is a device that is attached to the indoor side of a windowpane 11 of a building 1 and is capable of capturing moving and still images. The general configuration and functions of the imaging device 100 will be described with reference to Figures 1A and 1B, and the detailed configuration of the imaging device 100 will be described later using Figures 2A to 2C in addition to Figures 1A and 1B.

[0026] The imaging device 100 includes a lens 130 facing the indoor main surface 11B2 of the window glass 11, and captures an outdoor subject through the lens 130 and the window glass 11. The subject is, for example, the scenery seen through the window glass 11 (everything visible through the window glass 11), and the scenery may be, for example, a road, a sidewalk, a passageway, an intersection, an entrance / exit to a building 1, a ticket gate or entrance / exit to a station, etc., and may also include people, vehicles, etc. The imaging device 100 may also capture infrared images if it is capable of acquiring infrared images. Note that information captured by the imaging device 100 may be used for digital twin computing.

[0027] Such an imaging device 100 can be used for a variety of purposes, and the applications are not limited thereto. The imaging device 100 can be used for a variety of purposes to capture images of a subject outside the window glass 11 of the building 1. Here, as an example, a configuration in which the imaging device 100 is used as a security surveillance camera will be described. The imaging device 100 is disposed facing the indoor main surface 11B2 of the window glass 11, and is therefore difficult to see from the outside of the window glass 11 due to reflection. For this reason, use as a surveillance camera is an example of a suitable application of the imaging device 100.

[0028] The height at which the imaging device 100 is attached to the window glass 11 is preferably higher than the average human height, from the viewpoint of providing a good view of the area to be monitored. For example, the height at which the imaging device 100 is attached to the window glass 11 is preferably 2 m or more, and the imaging device 100 may be attached to a window glass 11 on the second floor or higher of the building 1. If the imaging device 100 is attached to the window glass 11 at a height of 2 m or more, it is less likely to be seen by the person to be monitored.

[0029] The height at which the imaging device 100 is attached to the window glass 11 may be set to a height at which an appropriate image can be captured, taking into consideration the imageable range depending on the angle of view of the imaging device 100, the distance to the subject, etc. The upper limit of the height at which the imaging device 100 is attached to the window glass 11 is the height of the top edge of the highest window glass 11 in the building 1. The height of the imaging device 100 may be defined as the height from a reference plane parallel to the horizontal plane (for example, the ground, floor, or virtual plane). The height of the imaging device 100 may also be the height of the lens 130.

[0030] <Detailed Configuration of Image Capturing Device 100> The detailed configuration of the image capturing device 100 will be described using Figures 2A to 2C in addition to Figures 1A and 1B. Figures 2A and 2B are diagrams showing an example of the configuration of the image capturing device 100. Figure 2C is a diagram showing an example of the configuration of a cross section taken along the line IIC-IIC in Figure 2B.

[0031] The imaging device 100 includes a case 110 , a magnet unit 120 , a lens 130 , and an imaging unit 140 .

[0032] <Case 110> The case 110 is a housing for the imaging device 100, and is a box-shaped housing that is triangular in plan view. In other words, the case 110 is a housing that is triangular in plan view and has a triangular prism shape with a low height in the Z-axis direction.

[0033] The case 110 may be made of resin or metal, for example. The resin material may be, for example, a thermoplastic resin. Examples of the thermoplastic resin include PC (polycarbonate) / ASA (Acrylate Styrene Acrylonitrile), ASA, or AES (Acrylonitrile Ethylene Styrene). Examples of the metal material may include aluminum, iron, stainless steel, etc.

[0034] The case 110 has, as surfaces exposed to the outside, a first surface 111, a second surface 112 (see particularly FIG. 2C ), and a side surface 113. Furthermore, as shown in FIG. 2C , the case 110 has an outer case 110A, an inner case 110B, an inner case 110C, and a holder 110D.

[0035] Hereinafter, when describing the positional relationship between the first surface 111, the second surface 112, and the side surfaces 113 (113A, 113B, and 113C), it may be expressed, for example, that the first surface 111 and the side surface 113A are connected. In this case, for example, even if the boundary between the outer case 110A and the inner case 110C is between the first surface 111 and the side surface 113A, and the first surface 111 and the side surface 113A are not physically connected, the first surface 111 and the side surface 113A are connected as long as they are connected in terms of the appearance of the case 110. In this way, the meaning of two surfaces being connected is the same for two surfaces other than the first surface 111 and the side surface 113A among the first surface 111, the second surface 112, and the side surfaces 113 (113A, 113B, and 113C).

[0036] <First Surface 111> The first surface 111 is located on the -Z axis direction side and is a surface parallel to the XY plane. The first surface 111 is an outer surface of the case 110 that faces the indoor-side main surface 11B2 of the window glass 11. As an example, the case 110 is arranged so that the first surface 111 abuts the indoor-side main surface 11B2 of the window glass 11. This is to reduce reflections of the window glass 11 in images acquired by the imaging unit 140 via the lens 130. However, the first surface 111 may be spaced apart from the main surface 11B2.

[0037] As an example, the first surface 111 has a shape of a right-angled isosceles triangle in a plan view, and has a recess 111A recessed in the +Z axis direction in the center. The surface of the recess 111A is recessed in a mortar shape and has a circular ring shape in a plan view. Note that, as an example, a configuration in which the first surface 111 has a shape of a right-angled isosceles triangle in a plan view will be described here, but the first surface 111 may have a shape of a right triangle in which the two sides other than the hypotenuse have different lengths in a plan view, or may have a shape other than a right triangle. Furthermore, the recess 111A may be provided at a position offset from the center of the first surface 111 in a plan view.

[0038] The recess 111A has an opening 111A1 in the center in a plan view, for example. The opening 111A1 exposes a portion of the lens 130 and the holder 110D. As an example, the recess 111A has a depth recessed into the first surface 111 so that the lens 130 and the holder 110D do not protrude further toward the −Z axis direction than the first surface 111 in the Z axis direction. In other words, as an example, the recess 111A has a depth recessed into the first surface 111 so that the lens 130 and the holder 110D are recessed further toward the +Z axis direction (toward the second surface 112) than the first surface 111 in the Z axis direction. This is to prevent the lens 130 and the holder 110D from contacting the main surface 11B2 of the window glass 11 when the imaging device 100 is placed facing the main surface 11B2 of the window glass 11 so that the first surface 111 abuts against the main surface 11B2 of the window glass 11.

[0039] Furthermore, the recess 111A is tapered so that the opening diameter in a plan view increases with increasing distance from the opening 111A1 to prevent the recess 111A from falling within the range of the angle of view determined by the lens 130 and the imaging unit 140. This is to prevent the recess 111A from appearing in an image captured by the imaging device 100. The orientation of the lens 130 is also changeable with respect to the case 110. The recess 111A has a tapered shape that widens widely so that the recess 111A does not appear in an image even when the orientation of the lens 130 is changed so that the angle of the lens 130 with respect to the Z axis is maximized.

[0040] Note that, as one example, recess 111A may have a depth in the Z-axis direction that makes lens 130 and holder 110D flush with first surface 111, or may have a depth in the Z-axis direction that makes lens 130 and holder 110D protrude further toward the −Z-axis direction than first surface 111. For example, such a configuration may be used when imaging device 100 is disposed facing main surface 11B2 of window glass 11 so that first surface 111 is spaced apart from main surface 11B2 of window glass 11.

[0041] The opening 111A1 may be offset from the center of the recess 111A in plan view.

[0042] <Second Surface 112> As shown particularly in FIG. 2C , the second surface 112 is a surface located opposite the first surface 111. For example, the second surface 112 has the shape of an isosceles right triangle that is the same shape and size as the first surface 111. The second surface 112 is parallel to the XY plane. In a plan view, the second surface 112 is positioned such that two adjacent sides of the second surface 112 that form a right angle with the hypotenuse overlap with two adjacent sides of the first surface 111 that form a right angle with the hypotenuse. The two adjacent sides are the two sides of the right triangle that form a right angle with the hypotenuse, i.e., the two sides of the right triangle other than the hypotenuse. Hereinafter, the two adjacent sides of the right triangle refer to the two sides of the right triangle other than the hypotenuse. Note that although the second surface 112 is not visible in FIGS. 1B , 2A , and 2B , its position is indicated by a symbol.

[0043] <Side Surfaces 113> The side surfaces 113 are composed of three side surfaces 113A, 113B, and 113C. Hereinafter, when there is no need to distinguish between the three side surfaces 113A, 113B, and 113C, they will be simply referred to as side surfaces 113. The side surfaces 113A, 113B, and 113C connect the first surface 111 and the second surface 112 of the outer surfaces of the case 110.

[0044] <Side surface 113A> Side surface 113A is a surface parallel to the XZ plane that connects one of two adjacent sides of first surface 111 that extends along the X axis and one of two adjacent sides of second surface 112 that extends along the X axis. Side surface 113B is connected to the +X axis direction side of side surface 113A, and side surface 113C is connected to the −X axis direction side of side surface 113A.

[0045] The side surface 113A has an opening 113A1 in the center when viewed from the XZ plane, for example. One of the two magnet portions 120 is embedded in the side surface 113A, and the magnet portion 120 is exposed through the opening 113A1. The side surface 113A and the portion of the magnet portion 120 exposed through the opening 113A1 are, for example, flush with each other.

[0046] Here, embedding the magnet part 120 in the side surface 113A means that the magnet part 120 may be exposed from the opening 113A1 of the side surface 113A as shown in FIG. 2B, or the side surface 113A may not have the opening 113A1, and the magnet part 120 may be covered by the side surface 113A and positioned inside the case 110.

[0047] As an example, one magnet portion 120 is embedded in the center of the side surface 113A when viewed in the XZ plane, but the position of the magnet portion 120 may be offset from the center in either direction in the XZ plane.

[0048] Also, as an example, a notch 113A2 for passing cable 101 (see FIG. 1A) is provided at the end of side surface 113A on the −X axis direction side and the −Z axis direction side. Note that the position of notch 113A2 is not limited to the position shown in FIG. 2B. Also, side surface 113A does not necessarily have to have notch 113A2.

[0049] <Side surface 113B> Side surface 113B is a surface parallel to the YZ plane and is at an angle different by 90 degrees from side surface 113A. Side surface 113B connects one of two adjacent sides of first surface 111 that extends along the Y axis to one of two adjacent sides of second surface 112 that also extends along the Y axis. Side surface 113A is connected to the +Y axis direction side of side surface 113B, and side surface 113C is connected to the -Y axis direction side of side surface 113B.

[0050] The side surface 113B has an opening 113B1 in the center when viewed in the YZ plane, for example. The other of the two magnet portions 120 is embedded in the side surface 113B, and the magnet portion 120 is exposed through the opening 113B1. The side surface 113B and the portion of the magnet portion 120 that is exposed through the opening 113B1 are, for example, flush with each other.

[0051] Here, embedding the magnet part 120 in the side surface 113B means that the magnet part 120 may be exposed from an opening 113B1 in the side surface 113B as shown in FIG. 2B, or the side surface 113B may not have an opening 113B1, and the magnet part 120 may be covered by the side surface 113B and positioned inside the case 110.

[0052] As an example, one magnet portion 120 is embedded in the center of the side surface 113B when viewed in the YZ plane, but the position of the magnet portion 120 may be offset from the center in either direction in the YZ plane.

[0053] Also, as an example, a notch 113B2 for passing the cable 101 (see FIG. 1A) is provided at the end of the side surface 113B on the -Y axis direction side and the -Z axis direction side. Note that the position of the notch 113B2 is not limited to the position shown in FIG. 2B. Also, the side surface 113B does not have to have the notch 113B2.

[0054] The case 110 may have either one of the notches 113A2 and 113B2 when the imaging device 100 is connected to the processing device via the cable 101. However, if the case 110 has both the notches 113A2 and 113B2, the direction in which the cable 101 is routed can be selected depending on the location where the imaging device 100 is installed.

[0055] <Side surface 113C> Side surface 113C is a surface that connects the hypotenuse of first surface 111 and the hypotenuse of second surface 112. Side surface 113C is a surface that has an angle of 45 degrees with respect to the XZ plane and the YZ plane. Side surfaces 113A and 113B are connected to side surface 113C. In addition, notches 113A2 and 113B2 are located at the ends of side surface 113C that contact side surfaces 113A and 113B.

[0056] <Outer case 110A> The outer case 110A has a second surface 112, side surfaces 113A, 113B, and 113C, and an opening 110A1. The outer case 110A is a case formed of a thin wall extending along the second surface 112 and side surfaces 113A, 113B, and 113C of a triangular prism-shaped case 110 having a low height in the Z-axis direction. In other words, the outer case 110A is a triangular prism-shaped case having an opening 110A1 on one surface in the -Z-axis direction where the first surface 111 is located, and having an internal cavity. The inner case 110B, the inner case 110C, and the holder 110D are housed inside the outer case 110A.

[0057] <Inner case 110B> The inner case 110B is the case located at the innermost side of the outer case 110A when viewed from the opening 110A1. The inner case 110B is triangular in plan view and has a through-hole 110B1 that penetrates in the Z-axis direction at its center in plan view. An inner surface 110B2 surrounding the through-hole 110B1 has a shape that corresponds to the inner surface of the remaining portion of a hemispherical shell, excluding a portion of the apex.

[0058] <Inner case 110C> The inner case 110C is a case that is arranged inside the outer case 110A on the near side as seen from the opening 110A1. The inner case 110C is arranged inside the outer case 110A in a state where it is stacked on top of the inner case 110B. The surface of the inner case 110C on the -Z axis direction side is the first surface 111.

[0059] The inner case 110C has a triangular shape in plan view and has a through-hole 110C1 that penetrates in the Z-axis direction at its center in plan view. The through-hole 110C1 has an opening 111A1 midway in the Z-axis direction. The opening 111A1 is the portion of the through-hole 110C1 between both ends in the Z-axis direction where the opening diameter is smallest in plan view. In other words, the opening 111A1 is the portion of the through-hole 110C1 between both ends in the Z-axis direction that protrudes most inward. The opening 111A1 is the portion that appears as an opening that exposes the holder 110D when the imaging device 100 is viewed from the -Z-axis direction (front direction) side.

[0060] The portion of through-hole 110C1 on the -Z-axis direction side of opening 111A1 is the internal space of recess 111A. Inner surface 110C2, which surrounds the portion of through-hole 110C1 on the +Z-axis direction side of opening 111A1, has a shape corresponding to the inner surface of the remaining portion of the hemispherical shell, excluding a portion on the apex side. Opening 111A1 is located on the apex side of this hemispherical shell. Inner surface 110C2 is in communication with inner surface 110B2 of inner case 110B, and has a shape corresponding to the inner surface of the remaining portion of the spherical shell, excluding the portions on the two apexes located on the Z-axis.

[0061] A magnet portion 120 is embedded in the side surfaces 113A and 113B of the case 110. FIG. 2C shows the magnet portion 120 embedded in the opening 113B1 of the side surface 113B of the outer case 110A. In practice, the magnet portion 120 is embedded in the outer case 110A and the inner cases 110B and 110C, as an example. Therefore, the inner cases 110B and 110C have openings that communicate with the opening 113B1 of the outer case 110A. The magnet portion 120 is embedded in the opening 113B1 of the outer case 110A and the openings of the inner cases 110B and 110C. This configuration is similar to that of the opening 113A1 of the side surface 113A of the outer case 110A, and the inner cases 110B and 110C also have openings that communicate with the opening 113A1.

[0062] <Holder 110D> The holder 110D is a hemispherical member and is disposed in a space defined by the inner surface 110C2 of the inner case 110C and the inner surface 110B2 of the inner case 110B. A recess 110D1 for accommodating the lens 130 is provided on the −Z axis direction side of the holder 110D. An opening is formed in the recess 110D1 at a portion that overlaps with the lens 130. The recess 110D1 is tapered so that the opening diameter in a plan view increases with increasing distance from the lens 130, so that the recess 110D1 does not fall within the range of the angle of view determined by the lens 130 and the imaging unit 140. This is to prevent the recess 110D1 from appearing in images captured by the imaging device 100.

[0063] Furthermore, a portion of holder 110D surrounding recess 110D1 is exposed to recess 111A through opening 111A1. Holder 110D also has a recessed accommodation portion 110D2 that accommodates imaging unit 140 on the back side (the +Z axis direction side in FIG. 2C ) of lens 130. Accommodation portion 110D2 communicates with recess 110D1 through the opening of recess 110D1.

[0064] Such holder 110D is configured to be rotatable relative to inner cases 110B and 110C along inner surfaces 110B2 and 110C2, thereby changing the orientation of lens 130. Note that case 110 does not necessarily have to have a configuration that allows the orientation of lens 130 to be changed in this way, and the orientation of lens 130 may be fixed.

[0065] <Magnet section 120> The magnet section 120 is, for example, a component in which a permanent magnet is covered with a magnetic metal, resin, or the like. The permanent magnet is preferably a magnet with a strong magnetic attraction force, such as a neodymium magnet. Examples of the magnetic metal that forms the portion covering the permanent magnet include iron and nickel, and examples of the resin material that forms the portion covering the permanent magnet include thermoplastic resins such as PC (polycarbonate) / ASA (Acrylate Styrene Acrylonitrile), ASA, or AES (Acrylonitrile Ethylene Styrene).

[0066] As an example, the imaging device 100 includes two magnet units 120. As shown in FIG. 2B , one magnet unit 120 is embedded in the center of the side surface 113A, and the other magnet unit 120 is embedded in the side surface 113B. As an example, the imaging device 100 is fixed to the window frame 12 by being magnetically attracted to the window frame 12 by the magnet units 120 (see FIG. 2B ) as shown in FIG. 1B . Note that if the window frame 12 is not made of a magnetic metal, as an example, the imaging device 100 may be fixed to the window frame 12 by attaching a magnetic metal sheet to the window frame 12 and magnetically attracting the magnet units 120.

[0067] Also, as an example, a configuration will be described in which the imaging device 100 includes the magnet portion 120 and is magnetically attracted to the window frame 12 made of magnetic metal. However, for example, the case 110 may be made of magnetic metal, a sheet-like magnet portion 120 may be attached to the window frame 12, and the case 110 may be magnetically attracted to the sheet-like magnet portion 120 attached to the window frame 12, thereby fixing the imaging device 100 to the window frame 12.

[0068] Furthermore, the imaging device 100 may be attached to the window frame 12 using an adhesive such as double-sided tape instead of the magnet unit 120. In this case, the adhesive such as double-sided tape can be attached to a portion that is not directly exposed to ultraviolet light between the side surface 113A or 113B of the case 110 of the imaging device 100 and the window frame 12. This is because even if the imaging device 100 is attached to the window frame 12 using an adhesive such as double-sided tape, deterioration due to ultraviolet light can be suppressed as long as the imaging device 100 is not directly exposed to ultraviolet light, and the imaging device 100 can be stably fixed to the window frame 12.

[0069] Additionally, while a form in which the imaging device 100 is fixed to the window frame 12 is described here as an example, the imaging device 100 may be fixed to a structure around the window glass 11 other than the window frame 12, such as the ceiling or wall around the window glass 11. If the ceiling or wall is not made of a magnetic metal, the imaging device 100 may be fixed to the ceiling or wall by attaching a magnetic metal sheet to the ceiling or wall. Alternatively, the case 110 may be made of a magnetic metal, and the imaging device 100 may be fixed to the ceiling or wall by attaching a sheet-like magnet portion 120 to the ceiling or wall. Alternatively, the imaging device 100 may be fixed to the ceiling or wall by attaching an adhesive such as double-sided tape to a portion between the ceiling or wall and the case 110 that is not directly irradiated with ultraviolet rays.

[0070] The imaging device 100 may also be fixed to the window frame 12 with a gap between them. For example, the imaging device 100 may be fixed to the window frame 12 with a box-shaped resin member that is transparent to visible light disposed between the imaging device 100 and the window frame 12. "Transparent" to visible light means that the visual transmittance is at least 40% or more, preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more. The imaging device 100 may also be fixed to the window frame 12 with a gap between them via a rod-shaped stay or other member.

[0071] The imaging device 100 may also be suspended from the ceiling via a member such as a stay. The imaging device 100 may also be adhered to the indoor main surface 11B2 of the window glass 11 with an adhesive or the like, or attached with double-sided tape. In these cases, the imaging device 100 may be fixed to the window frame 12 with a gap therebetween.

[0072] <Lens 130> The lens 130 is provided in the opening of the recess 110D1 of the holder 110D of the case 110. The opening of the recess 110D1 is connected to the storage section 110D2 on the back side of the recess 110D1, so the imaging section 140 provided in the storage section 110D2 can capture an image of the outdoor side of the window glass 11 through the opening of the recess 110D1 and the lens 130. Note that the lens 130 may also be provided on the second surface 112 so as to be able to capture an image of the indoor side as well as the outdoor side. Alternatively, the lens 130 may be provided only on the second surface 112 so as to be able to capture an image of only the indoor side.

[0073] <Image capture unit 140> The image capture unit 140 is a camera body capable of capturing moving and still digital images, and includes, for example, an image sensor that uses a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device) as an imaging element. The camera body is the portion of the camera excluding the lens 130. In other words, the image capture unit 140 and the lens 130 constitute a digital camera.

[0074] The imaging unit 140 is fixed inside the accommodation portion 110D2 of the holder 110D. This is for capturing an image of a subject outside the window glass 11 through the lens 130. The imaging unit 140 may or may not have a telephoto function. If the imaging unit 140 does not have a telephoto function, an inexpensive imaging unit 140 will suffice, allowing the imaging device 100 to be manufactured at low cost. The imaging unit 140 is connected to the processing device via a cable 101 (see FIG. 1B ).

[0075] 1B , a method of attaching the imaging device 100 to the window frame 12 will be described. As an example, at a corner portion on the +X-axis direction side and the +Y-axis direction side of the window frame 12, a frame portion 12X extending in the X-axis direction above the window glass 11 of the window frame 12 and a frame portion 12Y extending in the Y-axis direction on the +X-axis direction side of the window glass 11 form an angle of 90 degrees.

[0076] 1B , as an example, the imaging device 100 is placed in the upper corner of the window glass 11 and window frame 12. This is because the upper corner of the window frame 12 is unlikely to be visible to an unspecified number of people when viewed from the outside, and is therefore unlikely to be noticeable. Also, the imaging device 100 can be mounted at a certain height so that it can capture a wider range. However, the mounting position of the imaging device 100 is not limited to the upper corner of the window frame 12.

[0077] The main surface 11B2 of the window glass 11 has a side 11AX extending in the X-axis direction at its upper end and a side 11AY extending in the Y-axis direction on the +X-axis direction side. The sides 11AX and 11AY are connected to each other at a corner on the +X-axis direction and +Y-axis direction sides of the main surface 11B2, and the angle between the sides 11AX and 11AY is 90 degrees. In other words, the sides 11AX and 11AY are adjacent sides. Because the sides 11AX and 11AY are connected perpendicularly, the angle between the sides 11AX and 11AY and the frame portions 12X and 12Y of the window frame 12 that holds the window glass 11 is 90 degrees.

[0078] The imaging device 100 is fixed to the upper corner of the window frame 12 by abutting the side surfaces 113A and 113B (see FIG. 2B ) of the case 110 against the upper corner of the window frame 12 and magnetically attracting the magnet portion 120 to the window frame 12. The side surfaces 113A and 113B extend along the sides 11AX and 11AY, respectively. That is, the side surface 113A extends in the X-axis direction along the side 11AX, and the side surface 113B extends in the Y-axis direction along the side 11AY.

[0079] The angle between side surfaces 113A and 113B of case 110 of imaging device 100 is 90 degrees, allowing side surfaces 113A and 113B to abut against the inner corners of frame portions 12X and 12Y of window frame 12. Therefore, simply by pressing side surfaces 113A and 113B of imaging device 100 against the inner corners of frame portions 12X and 12Y of window frame 12, two magnet portions 120 of side surfaces 113A and 113B are magnetically attracted to frame portions 12X and 12Y. In this way, imaging device 100 can be easily attached to window frame 12.

[0080] Furthermore, the imaging device 100 has a triangular shape in a plan view and fits snugly into the inner corners of the frame portions 12X and 12Y of the window frame 12, so that the imaging device 100 appears to blend in with the window frame 12, resulting in good design.

[0081] <Surface Color of Recesses 110D1 and 111A of Case 110> Because the surfaces of the recesses 110D1 and 111A are located around the lens 130, it is preferable that they have low light reflectance. The surface color of the recesses 110D1 and 111A is preferably black, which absorbs light best, but may be a color other than black. As an example, the surfaces of the recesses 110D1 and 111A may be colored an appropriate color by applying paint. As an example, a paint that suppresses deterioration due to ultraviolet rays, such as a radical control paint, is preferable.

[0082] For example, the color of the surfaces of the recesses 110D1 and 111A may be any color with a brightness of not more than 5. The brightness represents the brightness defined by, for example, JIS Z8721-1993.

[0083] Because reflectance and brightness are correlated, a brightness of 5 or less corresponds to a visible light reflectance of 20% or less. If the visible light reflectance of the surfaces of the recesses 110D1 and 111A is 20% or less, it is possible to prevent strong incident light, such as sunlight, from being unnecessarily reflected by the recesses 110D1 and 111A and entering the lens 130, thereby preventing deterioration in the quality of the captured image.

[0084] For this reason, use as a surveillance camera is one example of a suitable use of the imaging device 100. When imaging outdoors as a surveillance camera, the imaging device 100 may be in a position where the sun is backlighting it depending on the time of day and the installation location. Even in such cases, it is easy to obtain high-quality images that include the subject when capturing images of the outdoors being monitored.

[0085] There are no particular restrictions on the hue and saturation of the color of the surfaces of the recesses 110D1 and 111A, and any color may be used as long as its brightness is equal to or less than 5. Examples of colors with a brightness of equal to or less than 5 include dark gray, in addition to black.

[0086] In this way, the reflectance of the surfaces of recesses 110D1 and 111A is sufficiently low, so that even without using a member that suppresses reflection, such as a so-called lens hood, a sufficiently clear image can be obtained with image capture device 100. Furthermore, because lens hoods are often made of a material that is susceptible to deterioration due to ultraviolet rays, such as silicone rubber, image capture device 100 does not include a lens hood, which is advantageous in terms of preventing deterioration due to ultraviolet rays.

[0087] <Color of Case 110> Of the surfaces of case 110, the portions other than recesses 110D1 and 111A of first surface 111 are visible from outside through window glass 11, and therefore preferably have a color that is less noticeable, similar to recesses 110D1 and 111A. For example, when imaging device 100 is used as a surveillance camera, it is less likely to attract attention if first surface 111 located in front of imaging device 100 is not visible from outside window glass 11.

[0088] Furthermore, since side surface 113C of case 110 is exposed when imaging device 100 is fixed to window frame 12, painting the case 110 the same color as or a color close to the color of window frame 12 makes the case 110 less noticeable, which is effective particularly when imaging device 100 is used as a surveillance camera. Note that side surfaces 113A and 113B are not visible when imaging device 100 is fixed to window frame 12. For this reason, the color of side surfaces 113A and 113B is not particularly important, but painting them the same color as side surface 113C improves the design of imaging device 100 when viewed alone and also simplifies the painting work of side surfaces 113A to 113C.

[0089] <Reducing Reflection Using Window Frame 12> In order to enable imaging device 100 to capture an image of the outdoors even when indoor lights are on at night without using a lens hood, imaging device 100 reduces reflection by using window frame 12. This will be described below with reference to Figures 3A, 3B, 4A, and 4B.

[0090] 3A and 3B are diagrams illustrating an example of why a reflected image is included in an image captured by a comparative imaging device 50, not an embodiment. The comparative imaging device 50 has the same camera configuration as the imaging device 100 of the embodiment shown in FIGS. 2A to 2C , but differs from the imaging device 100 of the embodiment in that there are no specifications for dimensions between the window frame 12 and the heat ray reflecting film 11C, which will be described later. The comparative imaging device 50 will be described as including a lens 130 and an imaging unit 140, just like the imaging device 100 of the embodiment.

[0091] As an example, Figure 3A shows an example of an XZ cross section of a portion in the X direction of a window glass 11 made of double-glazed glass, viewed from the +Y direction side. Figure 3A also shows a simplified image capture device 50. The optical axis of the lens 130 is C, and the horizontal angle of view of the image capture device 50 is θx. The Y-direction position of the XZ cross section shown in Figure 3A is a position that passes through the optical axis C of the lens 130. For ease of explanation, the image capture device 50 is assumed to be rectangular when viewed in the XZ plane and to have a shape that is symmetrical with respect to the optical axis C of the lens 130.

[0092] Here, using Figure 3A, we will explain the structure of the window glass 11, which is made of double-glazed glass, which makes it more difficult to reduce the reflection of reflected images compared to single-glazed glass, and then explain why the reflection of reflected images reflected by the window glass 11 is captured by the imaging device 50.

[0093] <Configuration of Window Glass 11 Consisting of Double Glazing> The window glass 11 made of double glazing has a glass plate 11A, a glass plate 11B, and a heat ray reflecting film 11C. The glass plate 11A is an example of a first glass plate on the outdoor side, and the glass plate 11B is an example of a second glass plate on the indoor side.

[0094] The heat ray reflective film 11C is a metal film that is transparent to visible light. "Transparent" to visible light means that the luminous transmittance is at least 40% or more, preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more.

[0095] The glass plate 11A has an outdoor-side main surface 11A1 and an indoor-side main surface 11A2. The glass plate 11B has an outdoor-side main surface 11B1 and an indoor-side main surface 11B2. The main surface 11A1 is an example of a first main surface, and the main surface 11A2 is an example of a second main surface. The main surface 11B1 is an example of a third main surface, and the main surface 11B2 is an example of a fourth main surface.

[0096] The main surface 11A1 is located closer to the outdoors than the main surface 11A2, and the main surface 11A2 is located closer to the indoor side than the main surface 11A1. The outdoor-side main surface 11A1 means that it is located closer to the outdoors than the main surface 11A2, and the indoor-side main surface 11A2 means that it is located closer to the indoor side than the main surface 11A1. The same applies to the main surfaces 11B1 and 11B2.

[0097] The glass plates 11A and 11B are spaced apart in the Z direction by spacers (not shown). The glass plates 11A and 11B have a uniform thickness and are parallel to the XY plane. The heat ray reflecting film 11C is formed on the main surface 11A2, as an example. In FIGS. 3A, 3B, 4A, and 4B, the Z direction thickness of the heat ray reflecting film 11C is exaggerated relative to the Z direction thicknesses of the glass plates 11A and 11B. Here, as an example, the heat ray reflecting film 11C is provided on the indoor-facing main surface 11A2 of the outdoor-facing glass plate 11A. However, the heat ray reflecting film 11C may also be provided on the outdoor-facing main surface 11B1 of the indoor-facing glass plate 11B. The spacers are made of, for example, metal or resin. The metal used for the spacers is, for example, aluminum or stainless steel.

[0098] The heat ray reflective film has a conductive film to reflect heat rays. The heat ray reflective film may also have layers other than the conductive film as long as the effects of the present disclosure are achieved. Hereinafter, layers other than the conductive film in the heat ray reflective film may be referred to as "other layers."

[0099] In this specification, the term "conductive film" refers to a film having an electrical resistivity of 100 [Ω·cm] or less at 20° C. The components of the conductive film are not particularly limited, but examples thereof include metals such as silver, aluminum, and stainless steel, which have excellent heat ray reflectivity, indium tin oxide (ITO), and tin oxide (SnO) doped with at least one of fluorine and antimony. ２ Preferably, the conductive film has as its main component an element selected from the group consisting of conductive film component group A, i.e., titanium nitride, niobium nitride, chromium nitride, zirconium nitride, and hafnium nitride (hereinafter also referred to as "conductive film component group A"). In this specification, the term "main component" refers to a component whose content relative to all constituent components is 50 atomic % or more. That is, the conductive film of this embodiment contains at least one component selected from the group consisting of conductive film component group A, and the conductive film of this embodiment preferably has a total content of conductive film component group A of 50 atomic % or more.

[0100] In order for the heat ray reflective film to exhibit excellent heat ray reflectivity, it is preferable that the conductive film contains at least one of silver and aluminum as a main component, and it is more preferable that the conductive film contains silver as a main component (i.e., contains 50 atomic % or more), and even more preferable that the conductive film contains 95 atomic % or more of silver.

[0101] Furthermore, the conductive film mainly composed of silver may contain one or more additive elements such as gold, palladium, copper, bismuth, neodymium, platinum, etc. By adding such additive elements to the conductive film mainly composed of silver, the diffusion of silver can be suppressed and moisture resistance can be improved. Note that the additive elements are not limited to those exemplified above, and any element can be added as long as the effects of the present disclosure are achieved.

[0102] From the viewpoint of durability, the heat ray reflective film preferably has a layer structure in which the conductive film is sandwiched between the other layers such as metal oxide layers and metal nitride layers. Examples of the metal oxide layer include metal oxide layers containing aluminum oxide, zinc oxide, indium oxide, titanium oxide, niobium oxide, tin oxide, bismuth oxide, tantalum oxide, tungsten oxide, zirconium oxide, silicon oxide, etc. as the main component. Among these, it is preferable that the metal oxide layer contains zinc oxide as the main component, since it is compatible with silver, which is a preferred component of the conductive film, and can increase the durability of the conductive film. Examples of the metal nitride layer include silicon nitride (Si ３ N ４ , aluminum nitride (AlN), titanium nitride, or the like.

[0103] <Why is it more difficult to reduce reflected images with double-glazed glass than with single-glazed glass> In a window glass 11 made of double-glazed glass, the distance between the lens 130 and the main surfaces 11A1 and 11A2 of the glass plate 11A located on the outdoor side is longer by the thickness of the spacer and the thickness of the glass plate 11, making it easier to capture reflected images. Furthermore, in double-glazed glass, the reflected image is further emphasized by providing a highly reflective heat-reflecting film 11C on the indoor-side main surface 11A2 of the outdoor-side glass plate 11A or on the outdoor-side main surface 11B1 of the indoor-side glass plate 11B. For these reasons, it is more difficult to reduce reflected images with double-glazed glass than with single-glazed glass.

[0104] <Reason why a reflected image is captured by the imaging device 50> Unless otherwise specified, the following will describe a case where the imaging device 50 captures an image of the outdoor side through the window glass 11 from the indoor side with the lights on at night. Nighttime refers to the period from sunset to sunrise, for example. When the lights are on at night, the outdoor side is dark, while the indoor side is bright.

[0105] If the reflectivity of the heat ray reflecting film 11C is higher than that of the glass plates 11A and 11B, when the window glass 11 is viewed from the indoor side, the reflection of the heat ray reflecting film 11C is more visible to the human eye than the reflection of the glass plates 11A and 11B. Therefore, the reflection of the heat ray reflecting film 11C will be more dominant than the reflection of the glass plates 11A and 11B in the image captured by the imaging device 50. For this reason, the reflection of the heat ray reflecting film 11C will be described here.

[0106] In Figure 3A, the thick arrow indicates the optical path of light that arrives from the +Z direction toward the -Z direction of the imaging device 50 and is reflected toward the +Z direction by the heat ray reflecting film 11C. Also in Figure 3A, the horizontal angle of view θx is divided into region (1) and region (2). Region (1) is a region where light heading toward the window glass 11 on the indoor side does not reach the heat ray reflecting film 11C. Region (2) is a region where light heading toward the window glass 11 on the indoor side reaches the heat ray reflecting film 11C.

[0107] 3A, the range of the horizontal angle of view θx and the boundaries between regions (1) and (2) are indicated by four dashed lines. The four dashed lines are folded back toward the lens 130 on the surface of the heat ray reflecting film 11C on the +Z direction side to indicate the boundaries of the regions through which light that arrives from the +Z direction side toward the −Z direction side of the image capturing device 50 and is reflected by the heat ray reflecting film 11C toward the +Z direction side passes.

[0108] Also, to make it easier to see the range of the horizontal angle of view θx and the regions (1) and (2), Figure 3B is used here. In Figure 3A, incident light arriving at the heat ray reflecting film 11C on the indoor side is shown in Figure 3B as light arriving at the window glass 11 from the -Z direction by being reflected back toward the -Z direction side of the heat ray reflecting film 11C. Therefore, in Figure 3B, the four dashed dotted lines representing the range of the horizontal angle of view θx and the regions (1) and (2) are shown as straight lines, and the optical path of the reflected light indicated by the thick arrow is shown as a straight line as the optical path of light arriving at the window glass 11 from the -Z direction side, passing through the heat ray reflecting film 11C, and reaching the lens 130.

[0109] 3B also shows an imaging device mirror image 50R, which is a mirror image of the imaging device 50 with respect to the heat ray reflecting film 11C, and a lens mirror image 130R, which is a mirror image of the lens 130. When the heat ray reflecting film 11C is viewed as a plane, the imaging device mirror image 50R and the lens mirror image 130R have shapes that are symmetrical to those of the imaging device 50 and the lens 130 with respect to the heat ray reflecting film 11C.

[0110] The XYZ coordinates shown in FIG. 3B are coordinates for the actual window glass 11 and imaging device 50, and are not used for the imaging device mirror image 50R, the lens mirror image 130R, or the optical path.

[0111] Region (1) at the center of the horizontal angle of view θx is a region that is in the shadow of the image capture device 50 and does not cause light reflection by the heat ray reflecting film 11C. Region (1) is a region located between two dashed dotted lines that pass through the center of the lens 130 and two corners of the housing of the image capture device 50 on the window glass 11 side. The optical path of light within region (1) will be described below with reference to Figures 3A and 3B.

[0112] In FIG. 3A , light (arrow 1A) traveling through area (1) on the indoor side toward the heat ray reflecting film 11C is blocked by the imaging device 50 and does not reach the heat ray reflecting film 11C, and is not reflected by the heat ray reflecting film 11C. Therefore, the light within area (1) does not enter the lens 130 and is not imaged by the imaging unit 140. This is explained below with reference to FIG. 3B . In FIG. 3B , light (arrow 1A) traveling through area (1) toward the heat ray reflecting film 11C is blocked by the imaging device mirror image 50R and does not reach the heat ray reflecting film 11C. Therefore, the light within area (1) (arrow 1A) does not enter the lens 130 and is not imaged by the imaging unit 140.

[0113] Region (2) within the horizontal angle of view θx is a region where light is reflected by the heat ray reflecting film 11C without being shaded by the imaging device 50. Region (2) consists of two regions located on both sides (the -X direction side and the +X direction side) of region (1). Region (2) consists of two regions obtained by excluding the central region (1) from the region included in the horizontal angle of view θx when viewed from the XZ plane. The optical path of light within region (2) will be described below using Figures 3A and 3B.

[0114] In FIG. 3A , light (arrow 2A) traveling through area (2) on the indoor side toward the heat ray reflecting film 11C is not blocked by the imaging device 50, and therefore reaches and is reflected by the heat ray reflecting film 11C. The light reflected by the heat ray reflecting film 11C passes through the lens 130 and is imaged by the imaging unit 140. In contrast, in FIG. 3B , light (arrow 2A) traveling through area (2) toward the heat ray reflecting film 11C is not blocked by the imaging device mirror image 50R, and therefore reaches and is reflected by the heat ray reflecting film 11C. In FIG. 3B , the light reflected by the heat ray reflecting film 11C is represented as light that passes through the heat ray reflecting film 11C and travels straight. The light reflected by the heat ray reflecting film 11C passes through the lens 130 and is imaged by the imaging unit 140. Therefore, the image captured by the imaging device 50 includes a reflection of the light (arrow 2A) that passed through area (2).

[0115] 4A and 4B are diagrams illustrating an example of why the imaging device 100 according to the embodiment can reduce the glare of a reflected image. First, a description will be given using FIG. 4A.

[0116] Similar to FIG. 3B , FIG. 4A shows an example of an XZ cross section of a portion in the X direction of a window glass 11 made of double-glazed glass, viewed from the +Y direction side. The Y direction position of the XZ cross section shown in FIG. 4A is a position passing through the optical axis C of the lens 130. FIG. 4A also shows a simplified version of the imaging device 100. The optical axis of the lens 130 is C. For ease of explanation, the imaging device 100 is assumed to be rectangular in the XZ plane view and symmetrical with respect to the optical axis C of the lens 130. The horizontal angle of view of the imaging device 100 is assumed to be θx.

[0117] Similar to Fig. 3B, Fig. 4A shows an imaging device mirror image 100R and a lens mirror image 130R, which are mirror images of the imaging device 100 and the lens 130. Fig. 4A also shows a window frame 12 and a window frame mirror image 12R, which is a mirror image of the window frame 12. More specifically, the window frame 12 shown in Fig. 4A is a frame portion 12Y that extends in the Y-axis direction on the +X-axis direction side of the window glass 11 of the window frame 12, and therefore is denoted by the reference symbol 12Y in parentheses, but will be described as the window frame 12 unless otherwise specified.

[0118] When the heat ray reflecting film 11C is viewed as a plane, the image capturing device mirror image 100R, the lens mirror image 130R, and the window frame mirror image 12R have shapes symmetrical to the image capturing device 100, the lens 130, and the window frame 12, respectively, with respect to the heat ray reflecting film 11C.

[0119] Note that the XYZ coordinates shown in Figure 4A are coordinates for the actual window glass 11 and imaging device 100, and unless otherwise specified, are not used for the imaging device mirror image 100R, lens mirror image 130R, window frame mirror image 12R, or optical path.

[0120] In FIG. 4A, as indicated by five dashed dotted lines, the horizontal angle of view θx is divided into an area (1), two areas (2), and one area (3).

[0121] The region (1) at the center of the horizontal angle of view θx is the same as the region (1) shown in Fig. 3B. Light passing through the region (1) on the indoor side toward the heat ray reflecting film 11C is blocked by the imaging device 100 and is not reflected by the heat ray reflecting film 11C. Therefore, the light does not enter the lens 130 and is not captured by the imaging unit 140.

[0122] Region (3) is the outer portion of region (2) on the +X direction side shown in Figure 3B in terms of the horizontal angle of view θx, and is the region where light is blocked by window frame mirror image 12R. Region (3) is the region between two dashed dotted lines: the dashed dotted line connecting the end on the +X direction side of the horizontal angle of view θx to the center of lens 130, and the dashed dotted line connecting the corner on the -X direction side of the -Z direction of window frame mirror image 12R to the center of lens 130.

[0123] Light passing through area (3) on the indoor side toward heat ray reflecting film 11C is blocked by window frame mirror image 12R and is not reflected by heat ray reflecting film 11C, and therefore does not enter lens 130 and is not imaged by imaging unit 140. Therefore, imaging device 100 can eliminate the glare of a reflected image that occurs when light passing through the outer portion of area (2) on the +X direction side shown in Figure 3B at the horizontal angle of view θx is reflected.

[0124] Note that the area (2) on the −X direction side is the same as the area (2) on the −X direction side shown in FIG. 3B, and therefore the image captured by the imaging device 100 includes a reflection of light (arrow 2A) that has passed through the area (2) on the −X direction side.

[0125] In Fig. 4A, region (2) exists between region (1) and region (3), but it is significantly narrower than region (2) on the +X direction side shown in Fig. 3B. The imaging device 100 uses the window frame 12 to reduce the glare of a reflected image that occurs when light incident from the window frame 12 side of the optical axis C of the lens 130 is reflected by the heat ray reflecting film 11C. On the +X direction side of the optical axis C of the lens 130, the window frame 12 is used instead of a lens hood.

[0126] 4B also shows a state in which the imaging device 100 is in contact with the indoor main surface 11B2 of the window glass 11. By placing the imaging device 100 closer to the window glass 11 than the imaging device 100 in FIG. 4A in this way, the area (2) between areas (1) and (3) can be narrowed or eliminated compared to the area (2) on the +X direction side shown in FIG. 4A. By installing the imaging device 100 as shown in FIG. 4B, it is possible to eliminate the glare of a reflected image caused by reflected light of light incident from the window frame 12 side relative to the optical axis C, and compared to the imaging device 100 shown in FIG. 4A, it is possible to reduce the glare of a reflected image caused by reflection by the heat ray reflective film 11C.

[0127] In this way, in order to reduce the glare of the reflected image caused by reflection on the heat ray reflective film 11C by utilizing a structure such as the window frame 12 that is in contact with the window glass 11, as an example, the position of the imaging device 100 relative to the window frame 12 (structure) and the window glass 11 can be set as follows using the horizontal angle of view θx, the distance Dx, and the distance Dz.

[0128] <Horizontal angle of view θx, distance Dx, distance Dz> In order to reduce the glare of a reflected image caused by light reflection on the heat ray reflecting film 11C, the imaging device 100 defines the horizontal angle of view θx shown in FIG. 4A , the distance Dx in the X direction between the lens 130 and the window frame 12, and the distance Dz between the lens 130 and the heat ray reflecting film 11C. Note that here, the horizontal angle of view θx and the distance Dx are defined in relation to the frame portion 12Y of the window frame 12, but in relation to the frame portion 12X of the window frame 12, it is sufficient to define the vertical angle of view θy of the lens 130 and the distance Dy in the Y direction between the lens 130 and the frame portion 12X. The distance Dz is common. The horizontal angle of view θx and the vertical angle of view θy are examples of the angle of view of the imaging device 100.

[0129] <Horizontal angle of view θx> The horizontal angle of view θx of the imaging device 100 is, for example, 40 degrees or more, and more preferably 70 degrees or more and 100 degrees or less. Since the imaging device 100 is intended to be used, for example, as a security surveillance camera, a certain degree of wide field of view is required.

[0130] 5AA to 5AF are used to explain the horizontal angle of view θx, which are diagrams showing examples of images captured by a camera at fixed points with the horizontal angle of view θx set to 40 degrees, 50 degrees, 70 degrees, 80 degrees, 105 degrees, and 120 degrees.

[0131] As shown in Figures 5AA to 5AF, in an image with a horizontal angle of view θx of 40 degrees (Figure 5AA at the top left), a building is visible on the left side, but the entire building is not included. The building is, for example, a 10-story building. In an image with a horizontal angle of view θx of 50 degrees (Figure 5AB at the top center), the entire building is visible on the left side, but the captured area is not very wide. In an image with a horizontal angle of view θx of 70 degrees (Figure 5AC at the top right), the entire building and its surroundings are included. In an image with a horizontal angle of view θx of 80 degrees (Figure 5AD at the bottom left), the entire building and its surroundings are included, covering an even wider area than the 70-degree image. In an image with a horizontal angle of view θx of 105 degrees (Figure 5AE at the bottom center), the entire building and its surroundings are included, but the image is distorted. In an image with a horizontal angle of view θx of 120 degrees (Figure 5AF at the bottom right), the image is even more distorted than the 105-degree image.

[0132] When imaging was performed with the horizontal angle of view θx set to values ​​less than 40 degrees and greater than 120 degrees, it was found that the field of view was too narrow when the horizontal angle of view θx was around 30 degrees, and the camera was difficult to use when it was less than 40 degrees. For these reasons, it is preferable that the horizontal angle of view θx be 40 degrees or greater.

[0133] 5AA to 5AF, it is more preferable that the horizontal angle of view θx is 70 degrees or more or 100 degrees or less. This is because a horizontal angle of view θx of 70 degrees or more can capture an image of a 10-story building and a wide area around it, and a horizontal angle of view θx of 100 degrees or less causes almost no distortion in the image.

[0134] From the above, it is preferable that the horizontal angle of view θx is equal to or greater than 40 degrees, and more preferably equal to or greater than 70 degrees or equal to or less than 100 degrees. The same applies to the vertical angle of view θy.

[0135] <Distance Dx in the X Direction Between the Lens 130 and the Window Frame 12> As shown in Figure 4A, the distance Dx in the X direction between the lens 130 and the window frame 12 is the distance in the X direction between the center of the lens 130 and the wall portion on the -X direction side of the window frame 12. Here, the X direction is a direction parallel to the main surface 11B2 of the window glass 11.

[0136] The distance Dx is preferably 0 mm or more and 180 mm or less. The reason for this will be explained using Figures 5B and 5C. Figure 5B is a diagram showing an example of a simulation result in which the glare reduction rate Rx (%) relative to the distance Dx is calculated by setting the horizontal angle of view θx from 40 degrees to 100 degrees in 10-degree increments. Figure 5C is a diagram showing an example of a calculation result when the horizontal angle of view θx shown in Figure 5B is 40 degrees.

[0137] Here, the glare reduction rate Rx (%) is the value (X3 / Xt) obtained by dividing the length X3 (see FIG. 4A ) in the X direction of the portion of the surface of the heat ray reflecting film 11C on the +Z direction side that is included in the horizontal angle of view θx by the length Xt of the portion of the surface of the heat ray reflecting film 11C on the +Z direction side that is included in region (3), where X3 is the length Xt. The glare reduction rate Rx (%) represents the ratio by which reflected light is reduced in the portion of the surface of the heat ray reflecting film 11C on the +Z direction side that is included in the horizontal angle of view θx.

[0138] The calculations were performed with the distance Dz set to 1 mm. The calculations were also performed with the length of the window frame 12 in the Z direction set to 500 mm, assuming that the Z-direction positions of the outdoor-side main surface 11A1 of the window glass 11 and the outer surface of the window frame 12, which is parallel to the XY plane in the -Z direction, are aligned. Generally, in buildings such as buildings, there are window frames 12 that have a sufficient Z-direction length extending indoors beyond the outdoor-side main surface 11A1 of the window glass 11. Furthermore, even if the Z-direction length of the window frame 12 itself is shorter than 500 mm, it is likely that there is a structure, such as an interior wall, that extends continuously from the window frame 12 in the +Z direction. Therefore, the Z-direction length of the window frame 12 was set to 500 mm.

[0139] As shown in Figure 5B, the glare reduction rate R reached a substantially equal peak value at a distance Dx of approximately 5 mm for all horizontal angles of view θx. Furthermore, at all horizontal angles of view θx, the glare reduction rate R tended to decrease substantially linearly as the distance Dx increased. Among the seven horizontal angles of view θx ranging from 40 degrees to 100 degrees, the glare reduction rate R was lowest at the narrowest angle of view θx of 40 degrees, and the glare reduction rate R tended to increase as the horizontal angle of view θx increased. This is thought to be because, as the horizontal angle of view θx increases, the area occupied by the window frame 12 within the horizontal angle of view θx increases, increasing the amount of light blocked by the window frame 12 and reducing the glare of a reflected image due to reflected light.

[0140] Furthermore, when the horizontal angle of view θx is 40 degrees, which is the narrowest, the glare reduction rate R was 1% when the distance Dx was 180 mm, but became 0% when the distance Dx exceeded 180 mm and increased to 190 mm.

[0141] From the above, it has been found that, in order to reduce the glare of a reflected image caused by reflection by the heat ray reflective film 11C using a structure such as the window frame 12 that is in contact with the window glass 11, the position of the imaging device 100 relative to the window frame 12 (structure) and the window glass 11 may be set so that the horizontal angle of view θx is 40 degrees or greater and the distance Dx is 0 mm or greater and 180 mm or less. The glare reduction rate Rx (%) is preferably greater than 0% and less than 50%. If Rx is greater than 0% and less than 50%, it is easy to capture an outdoor image at night even when indoor lighting is on without using a lens hood. Rx is more preferably greater than 10%, even more preferably greater than 20%, and particularly preferably greater than 30%. Rx may also be less than 45%, less than 40%, or less than 35%.

[0142] Additionally, the glare reduction rate Rx (%) has been described above, which represents the ratio of the reduction in reflected light in the portion of the surface of the heat ray reflecting film 11C on the +Z direction side that is included in the horizontal angle of view θx. However, because the frame portion 12X of the window frame 12 is located on the +Y direction side of the imaging device 100, the glare reduction rate Ry (%) can be calculated similarly for the vertical angle of view θy. The glare reduction rate Ry (%) represents the ratio of the reduction in the glare of the reflected image due to the reflected light by the frame portion 12X in the portion of the surface of the heat ray reflecting film 11C on the +Z direction side that is included in the vertical angle of view θy. The degree to which the imaging device 100 can reduce the glare of the reflected image by using the window frame 12 is calculated by subtracting the value of the overlapping portion of the glare reduction rates Rx and Ry from the sum of the glare reduction rates Rx and Ry. The glare reduction rate Ry (%) is preferably greater than 0% and less than or equal to 50%. If Ry is greater than 0% and less than or equal to 50%, it is easy to capture an outdoor image without using a lens hood, even when indoor lighting is on at night. Ry is more preferably 10% or more, even more preferably 20% or more, and particularly preferably 30% or more. Ry may also be 45% or less, 40% or less, or 35% or less.

[0143] <Distance Dz Between Lens 130 and Heat Ray Reflecting Film 11C> The distance Dz between the lens 130 and the heat ray reflecting film 11C is the distance in the Z direction between the apex of the lens 130, which is a convex lens that protrudes in the -Z direction, and the surface (reflecting surface) on the +Z direction side of the heat ray reflecting film 11C. If the window glass 11 is double-glazed, the distance Dz varies depending on the thickness of the spacer between the glass sheets 11A and 11B.

[0144] Lens 130 is provided at the opening of recess 110D1 of holder 110D of case 110, and it is preferable that the apex of lens 130 on the -Z direction side is set back in the +Z direction from first surface 111 of case 110, but the apex of lens 130 on the -Z direction side may be flush with first surface 111. Also, although heat ray reflective film 11C is provided on indoor-side main surface 11A2 of outdoor-side glass plate 11A in Figures 4A and 4B, it may also be provided on outdoor-side main surface 11B1 of indoor-side glass plate 11B.

[0145] Furthermore, when the imaging device 100 is positioned away from the window glass 11 in the +Z direction, the distance in the Z direction between the window glass 11 and the lens 130 increases, widening the area (2) between areas (1) and (3) shown in Fig. 4A (increasing the angle of area (2) when viewed from the XZ plane), increasing the glare of the reflected image based on the reflected light of light incident from the window frame 12 side rather than the optical axis C. From this perspective, simulations have shown that it is preferable for the distance Dz to be 100 mm or less.

[0146] From the above, when the reflectance of the heat ray reflecting film 11C is higher than the reflectance of the window glass 11, it is preferable that the distance Dz between the lens 130 and the heat ray reflecting film 11C be 0 mm or more and 100 mm or less in order to effectively reduce reflections caused by the heat ray reflecting film 11C.

[0147] Furthermore, even if the window glass 11 is double-glazed and has a heat ray reflective film 11C, if the reflectivity of the heat ray reflective film 11C is lower than the reflectivity of the window glass 11, reflections from the window glass 11 will be dominant. In this case, the distance in the Z direction between the focal point of the lens 130 and the outdoor main surface 11A1 of the outdoor-side glass plate 11A of the window glass 11 made of double-glazed glass is treated as the above-mentioned distance Dz, and reflections from the window glass 11 can be effectively reduced by setting the distance Dz between the focal point of the lens 130 and the outdoor main surface 11A1 of the outdoor-side glass plate 11A of the window glass 11 made of double-glazed glass.

[0148] 3A to 4B have been used to describe the case where the window glass 11 is double-glazed, but as mentioned above, the window glass 11 may also be single-glazed. If the window glass 11 is single-glazed and has a heat ray reflective film on its outdoor-facing main surface 11A1 (see FIG. 1B) or its indoor-facing main surface 11B2 (see FIG. 1B), and the reflectance of the heat ray reflective film is higher than the reflectance of the window glass 11, the distance Dz is the distance in the Z direction between the focal point of the lens 130 and the heat ray reflective film, just as in the case where the window glass 11 is double-glazed.

[0149] Furthermore, if the window glass 11 is a single-pane glass and does not have the heat ray reflecting film 11C, reflections will occur on the window glass 11. Therefore, if the window glass 11 is a single-pane glass and does not have the heat ray reflecting film 11C, the distance in the Z direction between the focal point of the lens 130 and the outdoor-side main surface 11A1 (see FIG. 1B ) of the window glass 11 made of single-pane glass is treated as the above-mentioned distance Dz, and reflections on the window glass 11 can be effectively reduced by setting the distance Dz between the focal point of the lens 130 and the outdoor-side main surface 11A1 of the window glass 11 made of single-pane glass.

[0150] Furthermore, even if the window glass 11 is a single-pane glass and has a heat ray reflective film 11C, if the reflectivity of the heat ray reflective film 11C is lower than the reflectivity of the window glass 11, reflections due to the window glass 11 will be dominant. In this case, the distance in the Z direction between the focal point of the lens 130 and the outdoor-side main surface 11A1 (see FIG. 1B ) of the window glass 11 made of single-pane glass is treated as the above-mentioned distance Dz, and reflections due to the window glass 11 can be effectively reduced by setting the distance Dz between the focal point of the lens 130 and the outdoor-side main surface 11A1 of the window glass 11 made of single-pane glass.

[0151] In window glass 11 made of single-pane glass without heat ray reflective film 11C, light arriving from the indoor side is reflected toward the indoor side by indoor main surface 11B2 (see FIG. 1B) and outdoor main surface 11A1 (see FIG. 1B). Reflection by outdoor main surface 11A1 occurs when light that has transmitted through indoor main surface 11B2 is reflected by the interior surface of window glass 11, i.e., outdoor main surface 11A1. Since window glass 11 has a visible light reflectance of approximately 4% each on main surface 11B2 and main surface 11A1, the total visible light reflectance is approximately 8%.

[0152] In this way, even if the window glass 11 is single-pane glass and does not have a heat-reflecting film 11C, the glare of the reflected image can be reduced by setting the position of the imaging device 100 so that the horizontal angle of view θx, the distance Dx, and the distance Dx satisfy the above-mentioned conditions, just as in the case described above where the window glass 11 is double-pane glass and has a heat-reflecting film 11C.

[0153] <Glare Reduction Rate Rx (%) with Respect to Distance Dx> FIG. 6 is a diagram illustrating an example of the glare reduction rate Rx (%) with respect to the distance Dx in the imaging device 100 according to the embodiment.

[0154] Similar to FIG. 4A , FIG. 6 shows an example of an XZ cross section of a portion in the X direction of a window glass 11 made of double-glazed glass, viewed from the +Y direction. The Y direction position of the XZ cross section shown in FIG. 6 is a position passing through the optical axis C of the lens 130. FIG. 6 also shows a simplified version of the imaging device 100. The optical axis of the lens 130 is C. For ease of explanation, the imaging device 100 is assumed to have a rectangular shape when viewed in the XZ plane and a shape symmetrical with respect to the optical axis C of the lens 130. The horizontal angle of view θx of the imaging device 100 is larger than the horizontal angle of view θx in FIG. 4A .

[0155] 6, like Fig. 4A, shows an imaging device mirror image 100R and a lens mirror image 130R, which are mirror images of the imaging device 100 and the lens 130. Fig. 6 also shows a window frame 12 and a window frame mirror image 12R, which is a mirror image of the window frame 12. More specifically, the window frame 12 shown in Fig. 6 is a frame portion 12Y that extends in the Y-axis direction on the +X-axis direction side of the window glass 11 of the window frame 12, and is therefore denoted by the reference symbol 12Y in parentheses, but will be described as the window frame 12 unless otherwise specified.

[0156] 6, in addition to the window frame 12, an outdoor-side window frame 12A is provided. The window frame 12A protrudes toward the outdoor side (-Z direction) beyond the outdoor-side main surface 11A of the glass plate 11A. As an example, the width of the window frame 12A in the X direction is equal to the width of the window frame 12 in the X direction. The length of the window frame 12A in the Z direction is shorter than the length of the window frame 12 in the Z direction, and the end of the window frame 12A on the -Z direction side is located closer to the +Z direction than the end of the window frame mirror image 12R on the -Z direction side. Therefore, the position of the end of the window frame mirror image 12R on the -Z direction side is equal to the position of the end of the window frame mirror image 12R on the -Z direction side shown in FIG. 4A.

[0157] When the heat ray reflecting film 11C is viewed as a plane, the image capturing device mirror image 100R, the lens mirror image 130R, and the window frame mirror image 12R have shapes symmetrical to the image capturing device 100, the lens 130, and the window frame 12, respectively, with respect to the heat ray reflecting film 11C.

[0158] The XYZ coordinates shown in FIG. 6 are coordinates for the actual window glass 11 and imaging device 100, and are not used for the imaging device mirror image 100R, lens mirror image 130R, window frame mirror image 12R, or optical path unless otherwise specified.

[0159] 6 mainly shows the portion on the +X side of the optical axis C, and omits part of the portion on the −X side of the optical axis C. In addition to regions (1) to (3), regions (4) and (5) are also shown on the +X side of the optical axis C in FIG. 6. In FIG. 6, regions (1) to (5) are all within the range of the horizontal angle of view θx. Regions (1) and (2) are the same as regions (1) and (2) shown in FIG. 4A.

[0160] 6, region (3) is an area outside region (2) on the +X direction side shown in Fig. 6 in terms of horizontal angle of view θx, where light is blocked by window frame mirror image 12R but not by window frame 12A as a real image. Region (3) is an area between two dashed dotted lines: a dashed dotted line connecting the corner on the -X direction side of window frame mirror image 12R and the center of lens 130 on the -Z direction side, and a dashed dotted line connecting the corner on the -X direction side of window frame 12A and the center of lens 130 on the -Z direction side.

[0161] Region (4) is a portion outside region (3) in the horizontal angle of view θx, and is a region between two dashed lines: a dashed line connecting the corner of the window frame 12A on the −Z direction side on the −X direction side to the center of the lens 130, and a dashed line connecting the edge of the heat ray reflecting film 11C on the +Z direction side on the +X direction side to the center of the lens 130. Region (4) is a region where light is blocked by the window frame 12A as a real image.

[0162] Region (5) is the outer portion of region (4) in terms of the horizontal angle of view θx, and is the region between two dashed lines: a dashed line connecting the +X-direction end of the +Z-direction surface of heat ray reflecting film 11C to the center of lens 130, and a dashed line connecting the +X-direction end of the horizontal angle of view θx to the center of lens 130.

[0163] Light 3A traveling through area (3) on the indoor side toward heat ray reflecting film 11C is blocked by window frame mirror image 12R and is not reflected by heat ray reflecting film 11C, so it does not enter lens 130 and is not captured by imaging unit 140. This makes it possible to eliminate the glare of a reflected image that occurs when light 3A passing through area (3) shown in Figure 6 is reflected.

[0164] It should be noted that light 4A and 5A passing through areas (4) and (5) is not reflected by the heat ray reflecting film 11C and does not enter the lens 130, just like light 3A in area (3). However, since the window frame 12A exists as a real image in areas (4) and (5), light 4A and 5A do not contribute to reducing the glare of the reflected image.

[0165] Even when the imaging device 100 has the window frame 12A, the window frame 12 can be used to reduce the glare of a reflected image that occurs when light that enters the lens 130 from the window frame 12 side relative to the optical axis C of the lens 130 is reflected by the heat ray reflecting film 11C. On the +X direction side of the optical axis C of the lens 130, the window frame 12 is used instead of a lens hood.

[0166] In order to reduce the glare of a reflected image caused by light reflection on the heat ray reflecting film 11C, the imaging device 100 defines distances d, e, f, and g shown in FIG. 6 in addition to the horizontal angle of view θx, the distance Dx in the X direction between the lens 130 and the window frame 12, and the distance Dz between the lens 130 and the heat ray reflecting film 11C shown in FIG. 6.

[0167] Distance d is the distance in the Z direction between the end of the window frame 12 on the +Z side and the heat ray reflecting film 11C, and is equal to the distance in the Z direction between the end of the window frame mirror image 12R on the -Z side and the heat ray reflecting film 11C. Distance e is the distance between the heat ray reflecting film 11C and the end of the window frame 12A on the -Z side. Distance f is the length between the lens 130 and the end of the window frame 12A on the -Z side, and f = Dz + e. Distance g is the length between the lens 130 and the end of the window frame mirror image 12R on the -Z side, and g = Dz + d.

[0168] Here, the horizontal angle of view θx, distance Dx, distance d, distance e, distance f, and distance g in the XZ plane are defined in relation to frame portion 12Y of window frame 12, but in relation to frame portion 12X of window frame 12, it is sufficient to define the vertical angle of view θy of lens 130, the distance Dy in the Y direction between lens 130 and frame portion 12X, and the distances d, e, f, and g in the XZ plane. The distance Dz is common. The horizontal angle of view θx and the vertical angle of view θy are examples of the angle of view of imaging device 100.

[0169] 6, the optical axis C of the lens 130 is parallel to the longitudinal direction in the Z direction, but to explain a more general state, the angle that the optical axis C makes with the Z direction is defined as θc. When viewed from the +Y direction, θc takes a positive value when tilted clockwise from the −Z direction toward the +X direction, and a negative value when tilted counterclockwise from the −Z direction toward the −X direction.

[0170] Whether the end of the window frame 12A on the -X direction side as a real image is reflected or not reflected when viewed from the lens 130 depends on whether f×tan(θx / 2+θc)>Dx is true. If f×tan(θx / 2+θc) is greater than Dx, the window frame 12A is reflected when viewed from the lens 130. If f×tan(θx / 2+θc) is equal to or less than Dx, the window frame 12A is not reflected when viewed from the lens 130. When the window frame 12A is not reflected when viewed from the lens 130, this means that the window frame 12A does not fall within the horizontal angle of view θx. When the window frame 12A is reflected when viewed from the lens 130, this means that the window frame 12A falls within the horizontal angle of view θx.

[0171] <When the window frame 12A is reflected when viewed from the lens 130> When the window frame 12A is reflected when viewed from the lens 130, the length X12 on the reflective surface of the heat ray reflective film 11C is expressed by the following formula (1) using the ratio of the length Dz to the distance f. Note that the length X12 is the sum of the length of the portion of the region (1) on the reflective surface of the heat ray reflective film 11C on the +X direction side of a line that passes through the center of the lens 130 and is parallel to the normal to the window glass 11, and the length of the region (2) on the +X direction side on the reflective surface of the heat ray reflective film 11C. X12 = Dx × Dz / g = Dx × Dz / (Dz + d) (1)

[0172] When the window frame 12A is reflected when viewed from the lens 130, the length X4 in the X direction of the region (4) on the reflective surface of the heat ray reflective film 11C is expressed by the following equation (2) using the ratio of the distance f to the distance e: X4 = Dx × e / f = Dx × e / (Dz + e) ​​(2)

[0173] When the window frame 12A is reflected when viewed from the lens 130, the length X5 in the X direction of the area (5) on the reflective surface of the heat ray reflective film 11C is expressed by the following equation (3): X5=Dz×tan(θx / 2+θc)−Dx (3)

[0174] Here, if the length in the X direction included in the horizontal angle of view θx on the reflective surface of the heat ray reflective film 11C is Xt, the length Xt is expressed by the following equation (4): Xt=Dz×{tan(θx / 2−θc)+tan(θx / 2+θc)} (4)

[0175] When the window frame 12A is reflected when viewed from the lens 130, the length X3 in the X direction of the region (3) on the reflective surface of the heat ray reflective film 11C is obtained by subtracting the lengths X12, X4, and X5 from the length Dz × tan(θx / 2 + θc), and is therefore expressed by the following equation (5): The length Dz × tan(θx / 2 + θc) is a length that takes into account the angle θc between the optical axis C of the lens 130 and the Z direction for the length Xt / 2, which is half the length Xt. X3=Dz×tan(θx / 2+θc)-X12-X4-X5=Dz×tan(θx / 2+θc)-Dx×Dz / (Dz+d)- Dx×e / (Dz+e)-(Dz×tan(θx / 2+θc)-Dx)=Dz×Dx×{1 / (Dz+e)-1 / (Dz+d)} (5)

[0176] From the above, the reflection reduction rate Rx (%) for the distance Dx when the window frame 12A is reflected when viewed from the lens 130 can be expressed by the following equation (6) using the lengths X3 and Xt: Rx = X3 / Xt x 100 = [Dz x Dx x {1 / (Dz + e) ​​- 1 / (Dz + d)}] / [Dz x {tan(θx / 2 - θc) + tan(θx / 2 + θc)}] x 100 = Dx x {1 / (Dz + e) ​​- 1 / (Dz + d)} / {tan(θx / 2 - θc) + tan(θx / 2 + θc)} x 100 (%) (6)

[0177] Here, the horizontal angle of view θx, distance Dx, distance d, distance e, distance f, and distance g when viewed in the XZ plane are specified in relation to the frame portion 12Y of the window frame 12, but in relation to the frame portion 12X of the window frame 12, it is sufficient to specify the vertical angle of view θy of the lens 130, the distance Dy in the Y direction between the lens 130 and the frame portion 12X, and the distances d, e, f, and g when viewed in the XZ plane.

[0178] The glare reduction rate Rx (%) relative to the distance Dx expressed by formula (6) is preferably greater than 0% and less than or equal to 50%. If Rx is greater than 0% and less than or equal to 50%, it is easy to capture an outdoor image without using a lens hood, even when indoor lighting is on at night. Rx is more preferably greater than or equal to 10%, even more preferably greater than or equal to 20%, and particularly preferably greater than or equal to 30%. Furthermore, Rx may be less than or equal to 45%, less than or equal to 40%, or less than or equal to 35%.

[0179] The glare reduction rate Ry (%) for the distance Dy when the window frame 12A is reflected when viewed from the lens 130 can be expressed by the following equation (7) using the lengths X3 and Xt: Ry=X3 / Xt×100=[Dz×Dy×{1 / (Dz+e)−1 / (Dz+d)}] / [Dz×{tan(θy / 2−θc)+tan(θy / 2+θc)}]×100=Dy×{1 / (Dz+e)−1 / (Dz+d)} / {tan(θy / 2−θc)+tan(θy / 2+θc)}×100(%) (7)

[0180] The glare reduction rate Ry (%) relative to the distance Dy expressed by formula (7) is preferably greater than 0% and less than or equal to 50%. If Ry is greater than 0% and less than or equal to 50%, it is easy to capture an outdoor image without using a lens hood, even when indoor lighting is on at night. Ry is more preferably greater than or equal to 10%, even more preferably greater than or equal to 20%, and particularly preferably greater than or equal to 30%. Furthermore, Ry may be less than or equal to 45%, less than or equal to 40%, or less than or equal to 35%.

[0181] <When the window frame 12A is not reflected when viewed from the lens 130> When the window frame 12A is not reflected when viewed from the lens 130, regions (4) and (5) do not exist in Fig. 6. Regions (4) and (5) do not exist, for example, when the horizontal angle of view θx is narrow and the window frame 12A is not reflected, or when the window frame 12A does not exist as in Fig. 4A.

[0182] In this case, the terms of length X4 and length X5 can be deleted from equation (5) within the XZ plane, and length X3 can be expressed by the following equation (8): X3=Dz×tan(θx / 2+θc)−X12=Dz×tan(θx / 2+θc)−Dx×Dz / (Dz+d) (8)

[0183] From the above, the reflection reduction rate Rx (%) for the distance Dx when the window frame 12A is not reflected when viewed from the lens 130 can be expressed by the following equation (9) using the lengths X3 and Xt in equation (8): Rx = X3 / Xt × 100 = Dz × tan(θx / 2 + θc) - Dx × Dz / (Dz + d) / [Dz × {tan(θx / 2 - θc) + tan(θx / 2 + θc)}] × 100 = {tan(θx / 2 + θc) - Dx / (Dz + d)} / {tan(θx / 2 - θc) + tan(θx / 2 + θc)} × 100(%) (9)

[0184] In relation to the frame portion 12X of the window frame 12, the reflection reduction rate Ry (%) for the distance Dy when the window frame 12A is reflected as viewed from the lens 130 can be calculated using the vertical angle of view θy of the lens 130, the distance Dy in the Y direction between the lens 130 and the frame portion 12X, and the distances d, e, f, and g in the XZ plane.

[0185] The glare reduction rate Rx (%) relative to the distance Dx expressed by formula (9) is preferably greater than 0% and less than or equal to 50%. If Rx is greater than 0% and less than or equal to 50%, it is easy to capture an outdoor image without using a lens hood, even when indoor lighting is on at night. Rx is more preferably greater than or equal to 10%, even more preferably greater than or equal to 20%, and particularly preferably greater than or equal to 30%. Furthermore, Rx may be less than or equal to 45%, less than or equal to 40%, or less than or equal to 35%.

[0186] The reduction rate Ry (%) can be expressed by the following formula (10) using the lengths X3 and Xt: Ry = X3 / Xt x 100 = Dz x tan(θy / 2 + θc) - Dy x Dz / (Dz + d) / [Dz x {tan(θy / 2 - θc) + tan(θy / 2 + θc)}] x 100 = {tan(θy / 2 + θc) - Dy / (Dz + d)} / {tan(θy / 2 - θc) + tan(θy / 2 + θc)} x 100 (%) (10)

[0187] The glare reduction rate Ry (%) with respect to the distance Dy expressed by formula (10) is preferably greater than 0% and less than or equal to 50%. If Ry is greater than 0% and less than or equal to 50%, it is easy to capture an outdoor image without using a lens hood, even when indoor lighting is on at night. Ry is more preferably greater than or equal to 10%, even more preferably greater than or equal to 20%, and particularly preferably greater than or equal to 30%. Furthermore, Ry may be less than or equal to 45%, less than or equal to 40%, or less than or equal to 35%.

[0188] <Effects> The imaging device 100 includes a case 110 (housing) having a surface (first surface 111) facing the indoor-side main surface 11B2 of a window glass 11 of a building, a lens 130 provided in an opening on the surface (first surface 111) of the case 110 and facing the main surface 11B2, and an imaging unit 140 provided within the case 110 and capable of capturing an image of the outdoor side of the window glass 11 via the lens 130, the imaging unit 140 having an angle of view of 40 degrees or more, and a distance Dx in a direction parallel to the main surface 11B2 between the lens 130 and a window frame 12 (structure) that contacts the window glass 11 being 0 mm or more and 180 mm or less. By positioning the imaging device 100 in this manner so that the distance Dx is within an appropriate range, the window frame 12 (structure) can be used to suppress incidence of light from the window frame 12 (structure) side relative to the optical axis C of the lens 130 onto the window glass 11, thereby reducing the glare of a reflected image due to the reflected light. Reflected images are particularly noticeable at night when indoor lights are on. From the standpoint of making it easier to move the imaging device 100 closer to structures such as window frames 12 and making it less noticeable, it is desirable to reduce reflected images without using a lens hood.

[0189] Therefore, it is possible to provide an imaging device 100 that can capture outdoor images even when indoor lighting is on at night without using a lens hood. Furthermore, because a lens hood is not used, it is easy to bring the lens 130 close to the window glass 11, and it is possible to realize a configuration that is not noticeable even when viewed from the outdoor side of the window glass 11.

[0190] Furthermore, the distance Dz between the lens 130 and the outdoor-facing principal surface 11A1 may be 0 mm or more and 100 mm or less. By positioning the imaging device 100 so that the distance Dz is within an appropriate range, it is possible to effectively reduce the glare of a reflected image. In particular, when the window glass 11 does not have a heat ray reflecting film 11C, or when the window glass 11 has a heat ray reflecting film 11C but the reflectance of the heat ray reflecting film 11C is lower than the reflectance of the window glass 11, it is preferable to position the imaging device 100 so that the distance Dz falls within this range.

[0191] The window glass 11 may also have a heat ray reflective film 11C, and the distance Dz between the lens 130 and the heat ray reflective film 11C may be 0 mm or more and 100 mm or less. By positioning the imaging device 100 so that the distance Dz is within an appropriate range, it is possible to effectively reduce the glare of a reflected image. If the window glass 11 has a heat ray reflective film 11C and the reflectance of the heat ray reflective film 11C is higher than the reflectance of the window glass 11, reflection from the heat ray reflective film 11C will be dominant, so it is preferable to position the imaging device 100 so that the distance Dz falls within this range.

[0192] Furthermore, the window glass 11 may be a double-glazed glass having an outdoor-side glass plate 11A (first glass plate) and an indoor-side glass plate 11B (second glass plate), and the heat ray reflective film 11C may be provided on the indoor-side main surface 11A2 of the glass plate 11A or the outdoor-side main surface 11B1 of the glass plate 11B. If the heat ray reflective film 11C is provided on the main surface 11A1 or 11A2, the distance Dz becomes longer, making it easier for a reflected image to appear. Therefore, by positioning the imaging device 100 so that the distance Dz is 0 mm or more and 100 mm or less, the reflected image can be effectively reduced.

[0193] Furthermore, the lens 130 may be positioned further away from the window glass 11 than the surface (first surface 111) of the case 110. By recessing the lens 130 in the +Z direction than the first surface 111, the amount of light incident on the lens 130 can be reduced, and the glare of reflected images can be effectively reduced.

[0194] The angle of view may be greater than or equal to 70 degrees and less than or equal to 100 degrees. Setting a more appropriate angle of view makes it possible to more effectively utilize the window frame 12 (structure) and suppress the incidence of light from the window frame 12 (structure) side of the optical axis C of the lens 130 onto the window glass 11, thereby further reducing the glare of reflected images.

[0195] Furthermore, in the case where a structure in contact with the window glass 11 is reflected when viewed from the lens 130, the horizontal distance between the lens 130 and the structure in contact with the window glass 11 is Dx, the distance between the lens 130 and the heat ray reflective film 11C is Dz, the horizontal angle of view is θx, the angle that the optical axis C of the lens 130 makes with the normal direction of the window glass 11 in a horizontal plane passing through the center of the lens 130 is θc, the normal distance between the outdoor side end of the structure in contact with the window glass 11 and the heat ray reflective film 11C is d, and the distance between the heat ray reflective film 11C and the outdoor side end of the structure in contact with the window glass 11 is e, the reflection reduction rate Rx (%) for the distance Dx expressed by the following formula (11) may be greater than 0% and less than 50%. Rx=Dx×{1 / (Dz+e)-1 / (Dz+d)} / {tan(θx / 2-θc)+tan(θx / 2+θc)}×100(%) (11)

[0196] In the case where a structure in contact with the window glass 11 is reflected when viewed from the lens 130 in the horizontal direction, the reflection reduction rate Rx (%) for the distance Dx can be calculated using formula (11), and if Rx is greater than 0% and less than or equal to 50%, it is easy to capture an image of the outdoors without using a lens hood, even when the indoor lights are on at night.

[0197] Furthermore, in the case where a structure in contact with the window glass 11 is reflected when viewed from the lens 130, the vertical distance between the lens 130 and the structure in contact with the window glass 11 is Dy, the distance between the lens 130 and the heat ray reflective film 11C is Dz, the vertical angle of view is θy, the angle that the optical axis C of the lens 130 makes with the normal direction of the window glass 11 in a vertical plane passing through the center of the lens 130 is θc, the normal distance between the outdoor side end of the structure in contact with the window glass 11 and the heat ray reflective film 11C is d, and the distance between the heat ray reflective film 11C and the outdoor side end of the structure in contact with the window glass 11 is e, the reflection reduction rate Ry (%) for the distance Dy, expressed by the following formula (12), may be greater than 0% and less than 50%. Ry=Dy×{1 / (Dz+e)-1 / (Dz+d)} / {tan(θy / 2-θc)+tan(θy / 2+θc)}×100(%) (12)

[0198] In the case where a structure in contact with the window glass 11 is reflected when viewed from the lens 130 in the vertical direction, the reflection reduction rate Ry (%) for the distance Dy can be calculated using formula (12), and if Ry is greater than 0% and less than or equal to 50%, it is easy to capture an image of the outdoors without using a lens hood, even when the indoor lights are on at night.

[0199] Furthermore, in a case where a structure in contact with the window glass 11 is not reflected when viewed from the lens 130, the horizontal distance between the lens 130 and the structure in contact with the window glass 11 is Dx, the distance between the lens 130 and the heat ray reflecting film 11C is Dz, the horizontal angle of view is θx, the angle that the optical axis C of the lens 130 makes with the normal direction of the window glass 11 in a horizontal plane passing through the center of the lens 130 is θc, and the normal direction distance between the outdoor side edge of the structure in contact with the window glass 11 and the heat ray reflecting film 11C is d, the reflection reduction rate Rx (%) with respect to the distance Dx expressed by the following formula (13) may be greater than 0% and less than or equal to 50%. Rx = {tan(θx / 2 + θc) - Dx / (Dz + d)} / {tan(θx / 2 - θc) + tan(θx / 2 + θc)} × 100(%) (13)

[0200] In the case where structures in contact with the window glass 11 are not reflected when viewed from the lens 130 in the horizontal direction, the reflection reduction rate Rx (%) for the distance Dx can be calculated using formula (13), and if Rx is greater than 0% and less than or equal to 50%, it is easy to capture an image of the outdoors without using a lens hood, even when the indoor lights are on at night.

[0201] In a case where a structure in contact with the window glass 11 is not reflected when viewed from the lens 130, the vertical distance between the lens 130 and the structure in contact with the window glass 11 is Dy, the distance between the lens 130 and the heat ray reflecting film 11C is Dz, the vertical angle of view is θy, the angle that the optical axis C of the lens 130 makes with the normal direction of the window glass 11 in a vertical plane passing through the center of the lens 130 is θc, and the normal direction distance between the outdoor side edge of the structure in contact with the window glass 11 and the heat ray reflecting film 11C is d, the reflection reduction rate Ry (%) with respect to the distance Dy expressed by the following formula (14) may be greater than 0% and less than or equal to 50%. Ry = {tan(θy / 2 + θc) - Dy / (Dz + d)} / {tan(θy / 2 - θc) + tan(θy / 2 + θc)} × 100(%) (14)

[0202] In the case where structures in contact with the window glass 11 are not reflected when viewed from the lens 130 in the vertical direction, the reflection reduction rate Ry (%) for the distance Dy can be calculated using formula (14), and if Ry is greater than 0% and less than or equal to 50%, it is easy to capture an image of the outdoors without using a lens hood, even when the indoor lights are on at night.

[0203] The window glass 200 with an imaging device includes the imaging device 100 described above and a window glass 11. By positioning the imaging device 100 so that the distance Dx falls within an appropriate range, the window frame 12 (structure) can be used to suppress the incidence of light from the window frame 12 (structure) side of the optical axis C of the lens 130 onto the window glass 11, thereby reducing the appearance of a reflected image due to reflected light. Reflected images are particularly noticeable when indoor lights are on at night. Furthermore, from the perspective of making it easier to move the imaging device 100 closer to structures such as the window frame 12 and making it less noticeable, it is desirable to reduce the appearance of a reflected image without using a lens hood.

[0204] Therefore, it is possible to provide a window glass 200 with an imaging device that can capture an image of the outdoors even when indoor lighting is on at night, without using a lens hood.

[0205] Although exemplary imaging devices and window glass with imaging devices according to the present disclosure have been described above, the present disclosure is not limited to the specifically disclosed embodiments, and various modifications and variations are possible without departing from the scope of the claims.

[0206] DESCRIPTION OF SYMBOLS 11 Window glass 11A Glass plate (an example of a first glass plate) 11B Glass plate (an example of a second glass plate) 11A1 Main surface (an example of a main surface on the outdoor side of the first glass plate) 11A2 Main surface (an example of a main surface on the indoor side of the first glass plate) 11B1 Main surface 11B2 Main surface (an example of a main surface on the indoor side) 11C Heat ray reflective film 12 Window frame (an example of a structure in contact with the window glass) 100 Imaging device 100R Mirror image of imaging device 110 Case (an example of a housing) 111 First surface (an example of a surface of a housing) 130 Lens 130R Mirror image of lens 140 Imaging unit The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2023-182227, filed on October 24, 2023, are hereby cited and incorporated as the disclosure of the specification of the present invention.

Claims

1. An imaging device comprising: a housing having a surface configured to face the indoor main surface of a window glass of a building; a lens provided in an opening on the surface of the housing and configured to face the main surface; and an imaging unit provided within the housing and configured to be able to image the outdoor side of the window glass through the lens, wherein the imaging device has an angle of view of 40 degrees or more, and the distance between the lens and a structure in contact with the window glass in a direction parallel to the main surface is configured to be 0 mm or more and 180 mm or less.

2. The imaging device according to claim 1, wherein the distance between the lens and the outdoor main surface of the window glass is configured to be equal to or greater than 0 mm and equal to or less than 100 mm.

3. The imaging device according to claim 1, wherein the window glass has a heat ray reflecting film, and the distance between the lens and the heat ray reflecting film is 0 mm or more and 100 mm or less.

4. The imaging device according to claim 3, wherein the window glass is a double-glazed glass having a first glass plate on the outdoor side and a second glass plate on the indoor side, and the heat ray reflective film is provided on the indoor side of the first glass plate or on the outdoor side of the second glass plate.

5. An imaging device according to any one of claims 1 to 4, wherein the lens is positioned on a side away from the window glass relative to the surface of the housing.

6. The imaging device according to any one of claims 1 to 5, wherein the angle of view is equal to or greater than 70 degrees and equal to or less than 100 degrees.

7. The imaging device according to any one of claims 1 to 6, wherein, in a case where a structure in contact with the window glass is reflected as viewed from the lens, the horizontal distance between the lens and the structure in contact with the window glass is Dx, the distance between the lens and the heat ray reflecting film is Dz, the horizontal angle of view is θx, the angle between the optical axis of the lens and the normal direction of the window glass in a horizontal plane passing through the center of the lens is θc, the distance in the normal direction between an outdoor side end of the structure in contact with the window glass and the heat ray reflecting film is d, and the distance between the heat ray reflecting film and the outdoor side end of the structure in contact with the window glass is e, a reflection reduction rate Rx (%) for the distance Dx expressed by the following formula (1) is more than 0% and 50% or less. Rx = Dx x {1 / (Dz + e) ​​- 1 / (Dz + d)} / {tan(θx / 2 - θc) + tan(θx / 2 + θc)} x 100 (%) (1) 8. The imaging device according to any one of claims 1 to 6, wherein, in a case where a structure in contact with the window glass is reflected as viewed from the lens, the vertical distance between the lens and the structure in contact with the window glass is Dy, the distance between the lens and the heat ray reflecting film is Dz, the vertical angle of view is θy, the angle between the optical axis of the lens and the normal direction of the window glass in a vertical plane passing through the center of the lens is θc, the distance in the normal direction between an outdoor side end of the structure in contact with the window glass and the heat ray reflecting film is d, and the distance between the heat ray reflecting film and the outdoor side end of the structure in contact with the window glass is e, a reflection reduction rate Ry (%) with respect to the distance Dy expressed by the following formula (2) is more than 0% and 50% or less. Ry = Dy x {1 / (Dz + e) ​​- 1 / (Dz + d)} / {tan(θy / 2 - θc) + tan(θy / 2 + θc)} x 100 (%) (2) 9. The imaging device according to any one of claims 1 to 6, wherein, in a case where a structure in contact with the window glass is not reflected as viewed from the lens, the horizontal distance between the lens and the structure in contact with the window glass is Dx, the distance between the lens and the heat ray reflecting film is Dz, the horizontal angle of view is θx, the angle that the optical axis of the lens makes with the normal direction of the window glass in a horizontal plane passing through the center of the lens is θc, and the distance in the normal direction between the outdoor side edge of the structure in contact with the window glass and the heat ray reflecting film is d, a reflection reduction rate Rx (%) with respect to the distance Dx expressed by the following formula (3) is more than 0% and 50% or less. Rx = {tan (θx / 2 + θc) - Dx / (Dz + d)} / {tan (θx / 2 - θc) + tan (θx / 2 + θc)} × 100 (%) (3) 10. The imaging device according to any one of claims 1 to 6, wherein, in a case where a structure in contact with the window glass is not reflected as viewed from the lens, the vertical distance between the lens and the structure in contact with the window glass is Dy, the distance between the lens and the heat ray reflecting film is Dz, the vertical angle of view is θy, the angle that the optical axis of the lens makes with the normal direction of the window glass in a vertical plane passing through the center of the lens is θc, and the distance in the normal direction between the outdoor side edge of the structure in contact with the window glass and the heat ray reflecting film is d, a reflection reduction rate Ry (%) with respect to the distance Dy expressed by the following formula (4) is more than 0% and 50% or less. Ry = {tan (θy / 2 + θc) - Dy / (Dz + d)} / {tan (θy / 2 - θc) + tan (θy / 2 + θc)} × 100 (%) (4) 11. A window glass with an imaging device, comprising: an imaging device according to any one of claims 1 to 10; and the window glass.

Images