Imaging device

Abstract

Provided is an imaging device having good camera mountability, design, and ranging accuracy. An imaging device provided in a vehicle, the imaging device comprising: a first camera having a first lens; a second camera having a second lens; a third camera having a third lens; and a case which houses the first, second, and third cameras and is mounted on the vehicle. The second lens is disposed at a position farther from the vehicle side than the first and third lenses. A part of an imaging range of the first camera overlaps a part of an imaging range of the second camera, and a part of an imaging range of the second camera overlaps a part of an imaging range of the third camera.

Description

Imaging device

[0001] The present invention relates to an imaging device that is mounted on a vehicle and captures images of the surroundings of the vehicle.

[0002] In autonomous driving, it is necessary to sense the surroundings of the vehicle using a camera mounted on the vehicle and obtain highly accurate and dense distance information.

[0003] In this regard, Patent Document 1 proposes a configuration as follows, with the aim of providing an imaging device and an in-vehicle camera system that can simultaneously perform wide-angle and telephoto photography while having a simple configuration: "an imaging device comprising a camera having a telephoto lens, a wide-angle means, and at least one mirror that reflects light emitted from the wide-angle means and makes it incident on a part of the imaging surface of the camera."

[0004] JP 2017-181634 A

[0005] The imaging device of Patent Document 1 is a camera module in which an optical system is configured with lenses with different angles of view (fisheye and narrow angle) and reflecting surfaces (prisms), and images with different angles of view and optical axes are formed on a single imaging element. As a result, there are problems such as no common imaging area and the distance between the cameras is short, making it impossible to achieve stereoscopic vision, reducing resolution because multiple images are formed on a single imaging element, and using reflections from a prism, resulting in a complex optical structure and high manufacturing costs.

[0006] In contrast, autonomous driving systems require technology that can measure distances and recognize the entire perimeter of the vehicle with high precision using multiple cameras. In particular, cameras for the side areas of the vehicle are expected to be mounted outside the passenger compartment, so ease of installation and design are also important.

[0007] To summarize these issues more specifically, autonomous driving requires imaging devices that are easy to install, have good design, and have good distance measurement accuracy.

[0008] Among these, ease of installation is an important factor in improving distance measurement performance, and the use of multiple cameras to obtain stereo information for distance measurement makes installation unstable (variable), which in turn affects distance measurement / recognition performance, necessitating improvements in the performance of the imaging device. Furthermore, in relation to installation, when designing and manufacturing an imaging device, assuming that it will be installed in a variety of vehicle models, it is necessary to consider where to install the cameras and to aim for simplification of manufacturing when installing multiple cameras (simplification of manufacturing).

[0009] In terms of design, cameras for the side areas of the vehicle are expected to be mounted outside the vehicle cabin, so it is desirable that they contribute to ensuring safety from contact with pedestrians, vehicle performance such as aerodynamic characteristics, and distance measurement performance.

[0010] These requirements for ease of installation and design ultimately focus on good distance measurement accuracy, but to achieve good distance measurement accuracy, it is necessary to consider that variations in the mounting positions of multiple cameras can make distance measurement / recognition performance unstable, necessitating the need for improved accuracy. This means that it is necessary to achieve both ease of installation (mountability) of multiple cameras and improved recognition performance.

[0011] SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide an imaging device that is easy to mount, has good design, and has good distance measurement accuracy.

[0012] In the present invention, the imaging device is configured as follows: "An imaging device to be installed in a vehicle, comprising: a first camera having a first lens; a second camera having a second lens; a third camera having a third lens; and a case that houses the first camera, the second camera, and the third camera and is attached to the vehicle, wherein the second lens is positioned farther away from the vehicle than the first lens and the third lens, and wherein a portion of the imaging range of the first camera overlaps with a portion of the imaging range of the second camera, and a portion of the imaging range of the second camera overlaps with a portion of the imaging range of the third camera."

[0013] According to the present invention, it is possible to provide an imaging device that has good camera attachment properties, design, and distance measurement accuracy.

[0014] In particular, according to the embodiment of the present invention, the ease of mounting to a vehicle, the design, and the accuracy of the relative position of the camera mounting are improved. Furthermore, by performing stereoscopic vision in the overlapping area, distance measurement is possible, and the area in which stereoscopic vision is possible can be widened.

[0015] 1 is a top view showing an example of the arrangement of vehicle-mounted cameras that enable 360° ranging for an autonomously driven vehicle; FIG. 2 is a side view showing an example of the arrangement of vehicle-mounted cameras that enable 360° ranging for an autonomously driven vehicle; FIG. 3 is a diagram showing an imaging range indicating a stereo field of view area; FIG. 4 is a diagram showing an example of installation of an imaging device according to a first embodiment of the present invention; FIG. 5 is a diagram showing the relationship between the camera arrangement positions, the imaging range of each camera, and the overlapping area when viewed from above the vehicle; FIG. 6 is a diagram showing a case where all camera lenses are arranged on the same plane in the front-to-rear direction of the vehicle at the sides of the vehicle; FIG. 7 is a diagram showing the imaging range and overlapping area when the second camera is arranged farther from the vehicle than the first and third cameras; FIG. 8 is a diagram showing the relationship between the imaging range and overlapping area between the first and third cameras with a wide field of view; FIG. 9 is a diagram showing an imaging device as viewed from the front side of the vehicle; FIG. 10 is a diagram showing an imaging device as viewed from the rear side of the vehicle; FIG. 11 is a diagram showing an imaging device as viewed from the top side of the vehicle; FIG. 12 is a diagram showing an imaging device as viewed from the bottom side of the vehicle; FIG. 13 is a side view showing the positional relationship with the imaging device when the physical mirror is retracted; FIG. 14 is a top view showing the positional relationship with the imaging device when the physical mirror is retracted; and FIG. 15 is a front view showing the positional relationship with the imaging device when the physical mirror is retracted. A diagram showing the exterior of a vehicle when an electronic mirror system is used. A diagram of an electronic mirror system imaging device viewed from the front of the vehicle. A diagram of an electronic mirror system imaging device viewed from the rear of the vehicle. A diagram of an electronic mirror system imaging device viewed from above the vehicle. A diagram of an electronic mirror system imaging device viewed from below the vehicle. A diagram viewed from diagonally front when the case of the imaging device is equipped with a lighting function. A diagram viewed from diagonally rear when the case of the imaging device is equipped with a lighting function.

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0017] 1 and 2 are top and side views of an autonomous vehicle showing an example of the placement of on-board cameras that enable omnidirectional ranging (360-degree stereoscopic viewing area) in the vehicle, and Fig. 3 shows the imaging range in this example.

[0018] In the example arrangements shown in FIGS. 1 and 2 , four camera groups are installed on an autonomous vehicle 1 (hereinafter simply referred to as the vehicle) for measuring distances in four directions: forward, backward, left, and right. The first camera group is a front camera group. As shown in the top view of FIG. 1 , the front camera group is made up of three cameras for forward distance measurement: a first front camera 5 (e.g., an 8MP (megapixel) narrow-angle camera with a 60-degree visual field), a second front camera 6 (e.g., an 8MP wide-angle camera with a 120-degree visual field), and a third front camera 7 (e.g., a 3MP wide-angle camera with a 200-degree visual field). The overlapping field of view of these three cameras provides a distance measurement range of 200 meters in front of the vehicle and a distance measurement range of 100 meters to the front and side of the vehicle, as shown as imaging range 10 in FIG. 3 .

[0019] The second camera group is a rear camera group. As shown in the top view of Fig. 1, the rear camera group is made up of two cameras for rear ranging: a first rear camera 8 (e.g., an 8MP, 120-degree wide-angle camera) and a second rear camera 9 (e.g., a 3MP, 200-degree wide-angle camera). The overlapping viewing areas of these two cameras provide a ranging range of 50 meters behind the vehicle and 100 meters to the rear and sides, as shown in Fig. 3 as an imaging range 10.

[0020] The third and fourth camera groups are left and right side camera groups of the vehicle. As shown in the top view of Figure 1, the left and right side camera groups are formed by three cameras for side ranging: a first side camera 2 (e.g., an 8MP, 120-degree wide-angle camera), a second side camera 3 (e.g., a 3MP, 200-degree fisheye camera), and a third side camera 4 (e.g., a 3MP, 120-degree wide-angle camera). The overlapping viewing areas of these three cameras provide a ranging range of 30 meters on the left and right sides of the vehicle 1, as shown as imaging range 10 in Figure 3.

[0021] 2 shows an example of the right side view of the vehicle, in which a first side camera 2 (e.g., an 8MP, 120° wide-angle camera), a second side camera 3 (e.g., a 3MP, 200° fisheye camera), and a third side camera 4 (e.g., a 3MP, 120° wide-angle camera) are arranged in this order from the rear of the vehicle.

[0022] 3 shows the imaging range 10 indicated by dotted lines, which indicates the stereo field of view obtained by combining the above camera arrangement, more specifically, the "front camera group and left and right side camera groups" and the "rear camera group and left and right side camera groups." This shows that appropriate distance measurement ranges are secured in each direction. This makes it possible to achieve all-around ranging (360-degree stereo field of view).

[0023] The imaging device according to the first embodiment of the present invention is particularly suitable for use with left and right side cameras, but this concept can also be applied to front and rear cameras. As will be described in detail below, the imaging device according to the first embodiment of the present invention aims to provide good camera installation and design, while minimizing the number of cameras. Regarding camera installation, cameras are concentrated on the side mirrors, installed in inconspicuous locations, and cameras for electronic mirrors are also used, thereby minimizing the number of cameras.

[0024] 4 is a diagram showing an example of installation of the image capturing device according to the first embodiment of the present invention. The image capturing device 13 is configured integrally with the physical mirror support parts 12 that attach the physical mirrors 11 on both sides of the vehicle 1 to the vehicle 1, or can be configured to be fixable to the physical mirror support parts 12. Furthermore, as will be described later in a third embodiment, in the case of a vehicle that does not have a physical mirror 11, the image capturing device 13 can be fixed directly to the door of the vehicle 1.

[0025] 4 shows an example in which the imaging device 13 is fixed to the physical mirror support part 12 by first, second, and third screw mounting parts 17, 18, and 19. By mounting the imaging device to the physical mirror support part 12, the modularized imaging device can be easily mounted to the vehicle. Furthermore, because the imaging device is fixed to the physical mirror support part 12 by the screw mounting parts 17, 18, and 19, rattle can be suppressed, and the effects of rattle on imaging and sensing can be suppressed.

[0026] However, regardless of how the imaging device 13 is fixed, the imaging device 13 is manufactured as a so-called unit configuration in which the first side camera 2, the second side camera 3, and the third side camera 4 are arranged in this order from the rear of the vehicle, and these cameras are integrally configured. In the following description, unless otherwise necessary, the first side camera 2, the second side camera 3, and the third side camera 4 may be referred to simply as cameras 2, 3, and 4. The surfaces of these cameras 2, 3, and 4 are covered by lenses (first lens 14, second lens 15, and third lens 16), respectively.

[0027] Three lenses 14, 15, and 16 are arranged on the surface of the imaging device 13, and three cameras 2, 3, and 4 are formed inside the imaging device 13 by an optical system that handles light from these lenses. These cameras are fixed at predetermined positions within the imaging device 3 while maintaining predetermined angles and predetermined dimensional differences, thereby ensuring predetermined imaging performance. In this way, the imaging device 13 is formed as a module with lenses on the surface of the case and cameras inside the case.

[0028] By configuring the imaging device 13 as a module of multiple cameras 2, 3, and 4, or by further fixing the imaging device 13 to the vehicle 1 via the physical mirror support part 12, the problem of unstable ranging / recognition performance due to variations in the positions at which multiple cameras are mounted and the need for improved accuracy is eliminated.

[0029] According to the camera arrangement in Figure 4, two wide-field cameras, a first camera 2 and a third camera 4 (wide-angle cameras), are arranged at the ends in the front-to-rear direction, and a fisheye-field second camera 3 (fisheye camera) is arranged sequentially between these wide-field cameras.

[0030] Furthermore, in the imaging device 13 according to Example 1 of the present invention, when the physical mirror support part 12 including the imaging device 13 is fixed to the vehicle 1, the distance between the vehicle 1 and the lens 15 of the second camera 3 is greater than the distance between the vehicle 1 and the lens 14 of the first camera 2 or the distance between the vehicle 1 and the lens 16 of the third camera 4.

[0031] In the installation example of Example 1 of the present invention, the position of lens 15 of second camera 3 may be about 1 cm higher from the side of vehicle 1 than the position of lens 14 of first camera 2, and this device is effective in improving distance measurement accuracy. How such an effect can be obtained will be explained below with reference to Figures 5, 6A, and 6B.

[0032] 5 is a diagram showing the camera arrangement, the imaging range of each camera, and the relationship between the overlapping areas when viewed from above the vehicle. As shown in this figure, the lens 15 at the tip of the second camera 3 is positioned farther from the vehicle 1 than the lenses 14, 16 at the tips of the first camera 2 and the third camera 4. In other words, the distance from the vehicle to the tip of the second camera 3 is greater than the distance from the vehicle to the tips of the first camera and the third camera.

[0033] In this figure, 20, 21, and 22 indicate the imaging ranges of the first camera 2, the second camera 3, and the third camera 4, respectively, 23 indicates the overlapping area between the first camera imaging range 20 and the second camera imaging range 21, and 24 indicates the overlapping area between the second camera imaging range 21 and the third camera imaging range 22.

[0034] With the imaging range and overlap area defined as above, Figure 6A shows a case where the lenses of all cameras 2, 3, and 4 are arranged on the same plane in the longitudinal direction of the vehicle, on the side of vehicle 1. In this figure, 25 indicates the baseline direction when the lenses of second camera 3 and third camera 4 are arranged on the same plane (same height from the side of vehicle 1). Also in this figure, 26 indicates the normal direction when the lenses of second camera 3 and third camera 4 are arranged on the same plane. Note that baseline direction 25 also shows the case where first camera 2 is arranged on the same plane, but because they are bilaterally symmetrical, the imaging ranges and overlap areas of second camera 3 and third camera 4 will be described here as representative examples.

[0035] In this figure, reference numeral 27 denotes a non-stereo viewing area, and 28 denotes a stereo viewing area when the lenses of the second camera 3 and the third camera 4 are arranged on the same plane. In the following explanation using Figure 6A, we will explain that when all cameras 2, 3, and 4 are arranged on the same plane, non-stereo viewing area 27 is formed.

[0036] Below, we will explain the operating principles of the imaging device, but first, when measuring the distance to an object using the stereo camera principle, the process of transforming the input images so that the objects in the two images are aligned on the same line is called rectification. Rectification requires image distortion correction, image rotation, projective transformation, etc. The stereo camera principle involves determining where the same object is captured in the left and right images, and estimating a 3D point cloud from the parallax.

[0037] When measuring a 3D point cloud based on parallax, there is a problem that the 3D point cloud cannot be estimated in the vicinity of the baseline direction 25 connecting the cameras. In reality, the cameras are occluded from each other, so the baseline direction 25 is not included in the calculation of the 3D point cloud, but the calculation accuracy of the 3D point cloud deteriorates in the vicinity of the baseline (the dashed region 27a in FIG. 6A ).

[0038] 6A, the baseline direction 25 of the second camera 3 and the third camera 4 is as shown in the figure, and the angle of view at the time of projection transformation is oriented in the lateral direction of the vehicle. In other words, in the area close to the baseline direction 25 (the area in front of the vehicle), the baseline length with respect to the projection surface is short, making it difficult to obtain parallax, and therefore the area does not become a substantial stereoscopic viewing area.

[0039] In contrast, in the stereoscopic viewing area 28 when the lenses of the second camera 3 and the third camera 4 are positioned on the same plane, the angle of view during projection transformation becomes a substantial stereoscopic viewing area, thereby improving distance measurement performance.

[0040] With respect to the normal direction 26 when the lenses of the second camera 3 and the third camera 4 are arranged on the same plane, the image of the second camera and the image of the third camera are projected and transformed in the normal direction 26 relative to the base line direction 25 of the second camera 3 and the third camera 4. This projection maximizes the parallax between the two cameras, which has the effect of improving distance measurement accuracy.

[0041] 6B shows the imaging range and overlap area when the lens of the second camera 3 is positioned farther from the vehicle 1 than the lenses of the first camera 2 and the third camera 4. Reference numeral 29 denotes the baseline direction of the first camera 2 and the second camera 3 when the second camera 3 is positioned farther from the vehicle side, and reference numeral 30 denotes the baseline direction of the second camera 3 and the third camera 4 when the second camera 3 is positioned farther from the vehicle side. The normals at this time are a first normal 31 to the baseline 29 and a second normal 32 to the baseline 30. As a result, a first stereo viewing area 33 and a second stereo viewing area 34 are obtained as stereo viewing areas.

[0042] 6B is clear from comparing it with FIG. 6A, no non-stereo viewing area 27 is formed according to the first embodiment of the present invention. Furthermore, for the stereo viewing area 34 (or 33), by positioning the lens of the second camera 3 outside the lens of the third camera 4, the baseline direction of the second camera 3 and the third camera 4 becomes as shown in 30 (or 29) in the figure, and the angle of view during projection transformation faces forward of the vehicle, thereby making it possible to ensure a wide effective stereo viewing area.

[0043] In this case, with respect to normal direction 32 (or 31), the image from second camera 3 and the image from third camera 4 are projected and transformed in the normal direction relative to the baseline direction of second camera 3 and third camera 4. This projection maximizes the parallax between the two cameras, which has the effect of improving distance measurement accuracy.

[0044] Above, using Figures 6A and 6B, we have explained the effect of placing the second camera 3 in the center farther from the vehicle 1 than the first and third cameras 2 and 4 at both ends (more precisely, the position of the lens on the front of the camera).

[0045] In Figures 6A and 6B, we have explained that the overlapping area between the first camera 2 and third camera 4 with a wide field of view and the second camera 3 with a fisheye field of view is the stereoscopic viewing area, but the overlapping area between the first camera 3 and third camera 4 with a wide field of view can also be the stereoscopic viewing area.

[0046] 7 is a diagram showing the relationship between the imaging range and the overlapping area in this case, and an overlapping area 35 can be obtained as the overlapping area between the imaging range 20 of the first camera 2 and the imaging range 22 of the third camera 4. The fact that overlapping area 35 can be obtained means that it can be treated as a stereo image area in subsequent signal processing and can be used as distance measurement information.

[0047] Returning to Figure 4, the first camera 2 and the third camera 4 at both ends of this imaging device 13 have their lenses 14, 16 facing almost horizontally, while the lens 15 of the second camera 3 in the center is not only positioned at a height away from the vehicle 1 but also facing slightly downward (toward the ground). This allows for capturing images of the lower side of the vehicle. In addition, the range of stereo vision can be widened, making it possible to apply stereo vision to both the rear and front.

[0048] In addition, in Figure 4, the third camera 4, the second camera 3, and the first camera 2 are arranged in this order from the front of the vehicle in the direction of travel, with the central axis of the third lens 16 facing forward in the direction of travel relative to the vehicle, and the central axis of the first lens 14 facing backward in the direction of travel relative to the vehicle 1. By specifying the position of each camera in this way, 3D sensing of the side of the vehicle is possible.

[0049] The first embodiment of the present invention described above is a camera device comprising: "an imaging device 13 provided on a vehicle 1, the imaging device comprising: a first camera 2 having a first lens 14; a second camera 3 having a second lens 15; a third camera 4 having a third lens 16; and a case 12 that houses the first camera 2, the second camera 3, and the third camera 4 and is attached to the vehicle 1; the second lens 3 is positioned further away from the vehicle than the first lens 14 and the third lens 16; and a camera device in which a portion of the imaging range of the first camera 2 overlaps with a portion of the imaging range of the second camera 3, and a portion of the imaging range of the second camera 3 overlaps with a portion of the imaging range of the third camera 4."

[0050] By adopting this configuration, the cameras are stored in a single case and the second camera 3 (fisheye) is positioned away from the vehicle, which increases the distance between the "baselines" of the first camera 2 (rear side) / third camera 4 (front side) and the second camera 3 (fisheye). This makes it possible to achieve both ease of installation (mountability) of multiple cameras and improved recognition performance (expansion of the parallax generation range).

[0051] In the second embodiment, a configuration example of the imaging device 13 fixed to the physical mirror 11 will be described.

[0052] First, the external configuration of the imaging device 13 fixed to the physical mirror 11 is as shown in Fig. 4. Figs. 8 to 11 show examples of the configuration when the external configuration of Fig. 4 is viewed from the front, back, top and bottom.

[0053] First, Fig. 8 shows the imaging device 13 as seen from the front side of the vehicle, and illustrates the configuration of the imaging device 13 as seen from the left side of Fig. 4. Fig. 9 shows the imaging device 13 as seen from the rear side of the vehicle, and illustrates the configuration of the imaging device 13 as seen from the right side of Fig. 4. Fig. 10 shows the imaging device 13 as seen from above the vehicle, and illustrates the configuration of the imaging device 13 as seen from the upper side of Fig. 4. Fig. 11 shows the imaging device 13 as seen from the lower side of the vehicle, and illustrates the configuration of the imaging device 13 as seen from the lower side of Fig. 4.

[0054] 8 , which shows the image capture device 13 viewed from the front of the vehicle, the third lens 16 of the third camera 4 is in the foreground, and the lens 15 of the second camera 3 is visible through the cover portion 39. On the opposite side of the cover portion 39, the image capture device 13 and the physical mirror support portion 12 are in contact with each other via a plurality of contact surfaces 36, 37. The cover portion 39 covers the protruding second camera 3.

[0055] 9 , which shows the image capture device 13 viewed from the rear of the vehicle, the first lens 16 of the first camera 2 is in the foreground, and the lens 15 of the second camera 3 is visible through the cover portion 39. On the opposite side of the cover portion 39, the image capture device 13 and the physical mirror support portion 12 are in contact with each other via a contact surface 38.

[0056] 10 , which shows the image capture device 13 viewed from above the vehicle, there is a physical mirror (here, physical mirror support portion 12) at the top, and below that, arranged in this order from the rear of the vehicle, are the third camera 4, the second camera 3, and the first camera 2. Here, when the case of the image capture device 13 is viewed from above in the vertical direction of the vehicle 1, the second camera 3 is positioned so as to overlap with the support portion 12 of the physical mirror.

[0057] 11, which shows the imaging device 13 viewed from the underside of the vehicle, there is a physical mirror (here, the physical mirror support part 12) at the bottom, and above that, arranged in this order from the rear of the vehicle, are the third camera 4, the second camera 3, and the first camera 2. In particular, Figure 11 shows that the second camera, which is a fisheye lens, is installed protruding (installed away from the vehicle).

[0058] 4, the image capturing device 13 is fixed to the physical mirror 11 via the physical mirror support part 12, and these integrated components are fixed to the vehicle 1 for use. For this reason, the physical mirror 11 is always disposed above the image capturing device 13. The physical mirror 11 is in an open state during normal driving, and is in a folded state (stored state) when the vehicle is stopped, etc. In either case, the distance between the tip of the physical mirror 11 and the vehicle is set to be greater than the distance between the tip of the image capturing device 13 and the vehicle.

[0059] 8 to 11 mainly show the connection relationship between the image capture device 13 and the physical mirror support part 12, but in reality, the physical mirror 11 itself is installed on top of the physical mirror support part 12. FIGS. 12 to 14 are side views, top views, and front views showing the positional relationship between the image capture device 13 and the physical mirror 11 when the physical mirror 11 is in the stored state. According to these positional and dimensional relationships, when the physical mirror 11 is in the stored state and the case of the image capture device 13 is viewed from above in the vertical direction of the vehicle, the case is positioned closer to the vehicle body than the position of the physical mirror farthest from the vehicle body, thereby protecting the electronic mirror (image capture device 13) from physical impact even if the vehicle 1 scrapes against a wall or the like.

[0060] 4 and 8 to 11, the case of the imaging device 13 is integrally molded with the support portion 12 of the physical mirror 11, and the integrally molded case of the imaging device 13 is fixed to face multiple surfaces (first abutment surface 36, second abutment surface 37, third abutment surface 38) at different angles relative to the vehicle body 1 and the support portion 12 of the physical mirror 11. Generally, misalignment of the camera directly affects detection accuracy, but in this case, because the camera is fixed on multiple surfaces, misalignment is less likely to occur, resulting in the effect of higher detection accuracy.

[0061] 10, the second fisheye camera 3 in the middle is positioned so as to overlap with the physical mirror support part 12. As a result, even if one or both of the two wide-angle cameras 2 and 4 are hit by a collision strong enough to destroy them, the second fisheye camera 3 is likely to be protected from the physical impact. As a result, image detection from the second fisheye camera 3 can continue.

[0062] 11, the second fisheye camera 4 is covered by a cover 39, which itself protrudes. This protrusion acts like a rain gutter to avoid water droplets bouncing off the vehicle body and to prevent water droplets from moving toward the lens.

[0063] In the first and second embodiments, it is assumed that the imaging device 13 is installed below the physical mirror 11 and fixed to the vehicle 1 .

[0064] In contrast, in Example 3, a physical mirror 11 is not installed, and only an imaging device 13 is installed outside the vehicle 1, and the stereo image obtained from the imaging device 13 is used to display on a display device inside the vehicle, thereby providing an electronic mirror system.

[0065] 15 is a diagram showing the appearance of a vehicle when an electronic mirror system is used, as seen from above. In this case, the physical mirror 11 is not installed in the door area, and only the image capture device 13 is installed near the installation position of the physical mirror.

[0066] The external configuration of the imaging device 13 when viewed from the side of the vehicle is shown in the lower part of Fig. 15, with the first camera 2, second camera 3, and third camera 4 arranged in this order from the rear of the vehicle. Fig. 16 to Fig. 19 show examples of the configuration when the external appearance of Fig. 15 is viewed from the front, back, top, and bottom.

[0067] First, Fig. 16 shows the imaging device 13 as seen from the front side of the vehicle, and illustrates the configuration as seen from arrow A in Fig. 4. Fig. 16 shows the imaging device 13 (electronic mirror) as seen from the rear side of the vehicle, Fig. 17 shows the imaging device 13 (electronic mirror) as seen from the rear side of the vehicle, Fig. 18 shows the imaging device 13 as seen from above the vehicle, and Fig. 19 shows the imaging device 13 as seen from below the vehicle.

[0068] One of the features of the configuration of this electronic mirror 13 is that, as shown in particular in Figure 18, the angle of the first camera 14 relative to the side of the vehicle is smaller than the angle of the third camera 4 relative to the side of the vehicle (part of the vehicle body is included in the angle of view), and the first camera 2 can also be used as a camera for the electronic side mirror.

[0069] One of the features of the configuration of this electronic mirror 13, as shown particularly in Figures 18 and 19, is that the case of the imaging device 13 has an outer surface with multiple curvatures, and the curvature of the outer surface of the case on which the first camera 2 and the third camera 4 are located is greater than the curvature of the outer surface of the case on which the second camera 3 is located, which reduces air resistance and may also have another effect of reducing lethality in the event of a collision.

[0070] In the fourth embodiment, the imaging device is provided with a lighting function.

[0071] Fig. 20 is a view from the diagonal front when the case of the imaging device is provided with a lighting function, and Fig. 21 is a view from the diagonal rear when the case of the imaging device is provided with a lighting function. A first lighting unit 41 and a third lighting unit 43 are provided on the side of the case of the imaging device, and a second lighting unit 42 is provided on the front of the case of the imaging device.

[0072] In this way, the case has lighting units 41, 42, and 43 that illuminate the area near the case, thereby improving image quality in dark places through illumination. In addition, the lighting units can also be used as turn signals, and the lighting light from the lighting units can be near-infrared, thereby improving sensing accuracy.

[0073] 1: Autonomous driving vehicle, 2: First side camera (first camera), 3: Second side camera (second camera), 4: Third side camera (third camera), 5: First front camera, 6: Second front camera, 7: Third front camera, 8: First rear camera, 9: Second rear camera, 10: Imaging range, 11: Physical mirror, 12: Physical mirror support part, 13: Imaging device, 14: First lens, 15: Second lens, 16: Third lens, 17, 18, 19: Mounting part, 36: First contact surface, 37: Second contact surface, 38: Third contact surface, 41: First lighting part, 42: Second lighting part, 43: Third lighting part

Claims

1. An imaging device installed in a vehicle, comprising: a first camera having a first lens; a second camera having a second lens; a third camera having a third lens; and a case that houses the first camera, the second camera, and the third camera and is attached to the vehicle, wherein the second lens is positioned farther away from the vehicle than the first lens and the third lens; and wherein a portion of the imaging range of the first camera overlaps with a portion of the imaging range of the second camera, and a portion of the imaging range of the second camera overlaps with a portion of the imaging range of the third camera.

2. The imaging device according to claim 1, wherein a portion of the imaging range of the first camera and a portion of the imaging range of the third camera overlap.

3. The imaging device according to claim 1, wherein the third camera, the second camera, and the first camera are arranged in this order from the front of the vehicle in the direction of travel, and the central axis of the third lens faces the front side of the vehicle in the direction of travel, and the central axis of the first lens faces the rear side of the vehicle in the direction of travel.

4. The imaging device according to claim 3, wherein the angle of the first camera relative to the side of the vehicle is smaller than the angle of the third camera relative to the side of the vehicle.

5. The imaging device of claim 1, wherein the case has an outer surface with a shape having multiple curvatures, and the curvature of the outer surface of the case on which the first camera and the third camera are arranged is greater than the curvature of the outer surface of the case on which the third camera is arranged.

6. The imaging device according to claim 1, wherein the case has a lighting unit that illuminates the vicinity of the case.

7. The imaging device according to claim 1, wherein the case has a mounting portion for mounting to a support portion of a physical mirror provided on the vehicle.

8. The imaging device according to claim 7, wherein the mounting portion has a first screw portion, a second screw portion, and a third screw portion.

9. The imaging device according to claim 7, wherein the case is fixed to face a plurality of surfaces at different angles relative to the support portion of the physical mirror.

10. The imaging device according to claim 7, wherein the second camera is positioned so as to overlap a support portion of the physical mirror when the case is viewed from above in the vertical direction of the vehicle.

11. The imaging device according to claim 1, wherein the cover portion of the case that covers the second camera protrudes further than the cover portions that cover the first camera and the third camera.

12. An imaging device as described in claim 10, wherein when the physical mirror is in a stored state, the case is positioned closer to the vehicle body than the farthest position from the vehicle body of the physical mirror when viewed from above in the vertical direction of the vehicle.

Images