Vehicle information imaging device

Abstract

To make it possible to reduce an influence of a vibration received by a camera.SOLUTION: A vehicle information imaging device 1 embedded under a road surface 11, which recognizes a license plate N arranged in a direction perpendicular to the road surface 11 of a vehicle traveling on the road surface 11, comprises: a transparent reinforced plate 2 having an upper surface 2a that is arranged in a flat state with respect to the road surface 11; a camera 3 installed below the transparent reinforced plate 2; and a free-form surface mirror 4 provided so that a focus of the camera 3 is uniformly aligned with the license plate N in a height direction of the license plate N.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a vehicle information imaging device. [Background technology]

[0002] On toll roads and the like, a method of photographing and recognizing the license plates of vehicles traveling on the roads involves burying a camera under the road surface (see, for example, Patent Document 1). Patent Document 1 discloses a number detection system in which a housing having a space capable of housing a camera is buried under the road surface, a transparent window member is disposed on the upper part of the housing so as to protrude obliquely above the road surface, and the license plates of traveling vehicles are photographed from the camera housed in the housing under the road surface through the window member protruding obliquely above the road surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-346281 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a method in which a camera is buried under the road surface and a window member is disposed protruding above the road surface, a moving vehicle will ride up on the part protruding above the road surface. Therefore, the camera is affected by vibrations that occur when a moving vehicle rides up on the housing, and the camera may not be able to focus on the subject to be photographed, or the camera itself may be prone to failure due to vibrations caused by the moving vehicle.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a vehicle information imaging device that can reduce the effects of vibrations on the camera. [Means for solving the problem]

[0006] In order to achieve the above-mentioned objective, a vehicle information imaging device according to one embodiment of the present disclosure is a vehicle information imaging device that is embedded in a road surface and is used to recognize an object to be photographed by a vehicle traveling on the road surface, and includes a transparent member having an upper surface that is positioned flat against the road surface, a camera installed below the transparent member, and a free-form surface mirror that is arranged so that the focus of the camera is uniformly aligned in the height direction with respect to the object to be photographed.

[0007] In addition, in the above-mentioned vehicle information imaging device, a folding mirror is provided that further reflects the image of the object to be photographed reflected in the free-form surface mirror toward the camera, and the camera may be positioned so that it can capture the image of the free-form surface mirror reflected in the folding mirror.

[0008] In the vehicle information imaging device, the camera may be housed in a housing that is provided with a buffer material in contact with the road surface.

[0009] In the vehicle information imaging device, the object to be photographed may be a license plate of the vehicle traveling in a lane, and the camera may be provided in the center of the lane in a width direction of the lane.

[0010] In the vehicle information imaging device, the object to be photographed may be a tire of the vehicle traveling along a lane, and the camera may be provided on a side of the lane in a lane width direction. Effect of the Invention

[0011] According to the vehicle information imaging device of the present invention, the influence of vibrations on the camera can be reduced. [Brief description of the drawings]

[0012] [Figure 1] 1 is a side view showing an overall configuration of a vehicle information imaging device according to a first embodiment. [Diagram 2] 1 is a vertical sectional view of a vehicle information imaging device according to a first embodiment. [Diagram 3]1 is a plan view of a vehicle information imaging device according to a first embodiment, viewed from above. [Figure 4] 1 is a first plan view showing an overall configuration in which a vehicle information imaging device according to a first embodiment is provided on a road surface, as viewed from above. [Diagram 5] FIG. 11 is a second plan view showing an overall configuration in which a vehicle information imaging device according to a second embodiment is provided on a road surface, as viewed from above. [Figure 6] FIG. 11 is a side view showing an overall outline of a vehicle information imaging device according to a second embodiment. [Figure 7] FIG. 11 is a diagram showing an example of an image obtained by photographing a mounted state of a tire according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, a vehicle information imaging device according to an embodiment of the present disclosure will be described with reference to the drawings. The embodiment shows one aspect of the present invention, and does not limit the present invention. The embodiment can be arbitrarily modified within the scope of the technical concept of the present invention.

[0014] <First embodiment> Hereinafter, the vehicle information imaging device according to the first embodiment will be described in detail with reference to FIGS.

[0015] (Overall configuration of vehicle information imaging device) Fig. 1 is a side view showing the overall configuration of a vehicle information imaging device, Fig. 2 is a vertical cross-sectional view of the vehicle information imaging device, and Fig. 3 is a plan view of the vehicle information imaging device as viewed from above.

[0016] 1 is used as one component of a toll collection system that collects tolls from a traveling vehicle A at a toll gate of a toll road. The vehicle information according to the first embodiment is a license plate N (image capture target).

[0017] As shown in FIG. 1, a vehicle A using a toll road travels on a lane L at a toll gate. In the following description, the direction in which the lane L extends (±X direction) is also referred to as the "lane direction", and the direction (±Y direction) horizontally perpendicular to the lane direction (±X direction) is also referred to as the "lane width direction". The forward side (-X direction side) of the traveling direction of the vehicle A is also referred to as the "upstream side", and the rear side (+X direction side) of the traveling direction of the vehicle A is also referred to as the "downstream side". The +Y direction side in the lane width direction (±Y direction) is the "left side in the traveling direction" of the vehicle A, and the -Y direction side in the lane width direction (±Y direction) is the "right side in the traveling direction" of the vehicle A. The direction (±Z direction) perpendicular to the plane including the lane direction (±X direction) and the lane width direction (±Y direction) is also referred to as the "up-down direction" (+Z direction is up).

[0018] The vehicle information imaging device 1 is a device that recognizes license plates N (N1, N2) provided at the front and rear of a vehicle A traveling on a lane L. Here, the license plate provided at the front of the vehicle A is also referred to as "license plate N1," and the license plate provided at the rear of the vehicle A is also referred to as "license plate N2." Note that Figs. 1 and 2 show an example of a device that recognizes the license plate N2 provided at the rear of the vehicle A. Although not shown, the vehicle information imaging device 1 provided to recognize the license plate N1 provided at the front of the vehicle A has the same configuration and is disposed with the lane direction (±X direction) facing in the opposite direction. Therefore, a detailed description of the vehicle information imaging device that recognizes the front license plate N1 is omitted here.

[0019] The vehicle information imaging device 1 is embedded under (on the -Z direction side of) a road surface 11 of a lane L, and is intended to recognize a license plate N2 of a vehicle A traveling on the road surface 11. Here, the license plate N (N1, N2) is disposed such that the plate surface is perpendicular to the road surface 11.

[0020] As shown in Figures 1 and 2, the vehicle information imaging device 1 comprises a transparent reinforcing plate 2 (transparent member) having an upper surface 2a that is placed flat against the road surface 11, a camera 3 installed below the transparent reinforcing plate 2, a free-form surface mirror 4 arranged so that the focus of the camera 3 is uniformly aligned in the vertical direction (±Z direction) with respect to the license plate N, and a folding mirror 5 that further reflects the image of the license plate N reflected on the free-form surface mirror 4 toward the camera 3. 2, the vehicle information imaging device 1 is provided with a housing 6 that is provided against a road surface 11 via a buffer material 64. Inside the housing 6, a camera 3, a free-form surface mirror 4, and a folding mirror 5 are housed.

[0021] The transparent reinforcing plate 2 is a plate-like member made of a colorless and transparent material such as reinforced glass or polycarbonate, and has a strength and thickness sufficient to withstand the load of a vehicle A traveling on the upper surface 2a. The transparent reinforcing plate 2 is circular in top view as shown in Fig. 3. The upper surface 2a of the transparent reinforcing plate 2 is disposed so as to be flush with the road surface 11 as shown in Figs. 1 and 2. That is, the transparent reinforcing plate 2 is placed in a flat state with respect to the road surface 11 as described above. Here, the "flat state with respect to the road surface 11" characteristic of the transparent reinforcing plate 2 includes a case where the transparent reinforcing plate 2 has minute irregularities that do not impede the travel of the vehicle A even when the tires of the vehicle A run over the transparent reinforcing plate 2. For example, irregularities of the same size as road studs installed at intersections and the like are within a range that does not impede the travel of the vehicle A.

[0022] The transparent reinforcing plate 2 is removably attached to the road surface 11 by a fixing jig 20. The fixing jig 20 is formed in a ring shape, and fixes the transparent reinforcing plate 2 by sandwiching the outer periphery 2b of the transparent reinforcing plate 2 from above and below on the inner periphery side of the ring. In this way, the transparent reinforcing plate 2 is fixed in the circular hole 11a of the road surface 11. The fixing jig 20 includes a ring body 21 extending in the circumferential direction, and a ring-shaped pressing plate 22 fixed from above the ring body 21 with screws 23.

[0023] The inner periphery of the ring body 21 has a mounting portion 211 that protrudes radially inward over the entire circumference, on which the outer periphery 2b of the transparent reinforcing plate 2 is mounted via a packing 24. The inner periphery 22a of the pressing plate 22 faces the mounting portion 211 of the ring body 21 in the vertical direction (±Z direction). The outer periphery 2b of the transparent reinforcing plate 2 is pressed and fixed from above by the inner periphery 22a of the pressing plate 22 fixed to the ring body 21 in a state where it is placed on the mounting portion 211 of the ring body 21. The lower surface 21b of the ring body 21 has a female thread 22b for fixing the housing 6 with a bolt 65. The upper surface 21a of the ring body 21 is flush with the road surface 11. The pressing plate 22 protrudes above the road surface 11. The pressing plate 22 is set to a plate thickness t within a range that does not interfere with the running of the vehicle A.

[0024] 2, the housing 6 has a cylindrical shape with a circular cross section and a bottom, and is fixed to the lower surface 21b of the ring body 21 of the fixing jig 20. The housing 6 has a cylindrical portion 61 whose cylindrical axis direction faces the up-down direction (±Z direction), a bottom portion 62 that closes the lower opening of the cylindrical portion 61, and a flange portion 63 that protrudes radially outward from the entire upper edge of the cylindrical portion 61. The flange portion 63 has a bolt hole 63a, and is fixed to the lower surface 21b of the ring body 21 from below via a buffer material 64. A bolt 65 is inserted into the bolt hole 63a of the flange portion 63 from below, and is fastened to the female thread 22b of the ring body 21.

[0025] The cushioning material 64 is made of an elastically deformable material such as rubber or foamed resin, which absorbs vibrations from the road surface 11 and is less likely to be transmitted to the housing 6. It is preferable that the cushioning material 64 also has water-stopping properties.

[0026] The housing 6 attached to the fixing jig 20 has an upper part of a cylindrical portion 61 covered by a transparent reinforcing plate 2. The cylindrical portion 61 has a through hole 61a. A power cable 31 and a communication cable of the camera 3 arranged inside the housing 6 are passed through the through hole 61a.

[0027] The camera 3 is disposed so as to be able to capture an image of the free curved surface mirror 4 reflected on the folding mirror 5. The camera 3 is disposed with the lens 3a facing upward (towards the +Z direction).

[0028] The free-form surface mirror 4 has a concave surface 4a set to a predetermined curvature, and is installed so as to reflect the upward (+Z direction) diagonally downstream side (+X direction side). The free-form surface mirror 4 is installed so that the camera 3 is uniformly focused in the height direction on the license plate N, which is the object to be photographed. Here, the plate surface (display surface) of the license plate N of the vehicle A traveling on the road surface is usually oriented along a plane (YZ plane) perpendicular to the lane direction (±X direction) (see Figs. 1 and 2). Therefore, normally, a camera arranged under the road surface looking up from below (-Z direction side) to above (+Z direction side) cannot capture the plate surface of the license plate N in the above-mentioned orientation. However, as in this embodiment, by interposing a free-form surface mirror 4 with an appropriately adjusted curvature between the camera 3 and the license plate N, a state is created in which the focus of the camera 3 is uniformly aligned in the up-down direction (±Z direction) of the plate surface of the license plate N. As a result, the image of the license plate N captured by the camera 3 is as if it were captured by a camera arranged horizontally on the road surface.

[0029] The folding mirror 5 is a plane mirror. The folding mirror 5 is arranged so that its mirror surface faces the free-form surface mirror 4 and the lens 3a so that the image of the license plate N reflected on the free-form surface mirror 4 can be guided to the lens 3a of the camera 3 arranged below it.

[0030] (Example of vehicle information imaging device placement) FIG. 4 is a first plan view of an overall configuration in which the vehicle information imaging device according to the first embodiment is provided on a road surface, as viewed from above. Next, an example in which the vehicle information imaging device 1 having the above-mentioned configuration is arranged on a road will be described with reference to FIG.

[0031] As shown in FIG. 4, the vehicle information imaging device 1 is provided in pairs in each of a plurality of lanes L (four lanes in FIG. 4), with a vehicle information imaging device 1A for photographing a front license plate N1 and a vehicle information imaging device 1B for photographing a rear license plate N2.

[0032] The vehicle information imaging devices 1A, 1B are embedded in the road surface 11 in the center of the lane in the lane width direction (±Y direction). The cameras 3 of the vehicle information imaging devices 1A, 1B capture images of the license plates N1, N2 of the vehicle A traveling in the lane L in which the pair of vehicle information imaging devices 1A, 1B are arranged in the lane direction (±X direction).

[0033] Vehicle information imaging device 1B, which captures an image of license plate N2 on the rear side of vehicle A, corresponds to the configuration shown in Figures 1 and 2. Vehicle information imaging device 1A, which captures an image of license plate N1 on the front side of vehicle A, is installed so that concave curved surface 4a of free-form surface mirror 4 reflects the upper diagonally upstream side. Here, the range (angle of view 3R) indicated by the two-dot chain line in Figure 4 indicates the angle of view of camera 3 in each of vehicle information imaging devices 1A, 1B.

[0034] A light (not shown) for illuminating the license plate N photographed by the camera 3 may be provided at a position adjacent to the vehicle information imaging device 1 in the lane width direction (±Y direction). In this case, the image of the license plate N becomes clearer by illuminating the license plate N with the light.

[0035] (Action and effect) According to the above-described vehicle information imaging device 1, the upper surface 2a of the transparent reinforcing plate 2 is placed flat and without irregularities against the road surface 11, and the camera 3 is installed below the transparent reinforcing plate 2. The free-form surface mirror 4 is provided so that the camera 3 is focused uniformly in the height direction on the license plate N, which is the object to be photographed. In this way, the vehicle information imaging device 1 according to this embodiment is equipped with the free-form surface mirror 4, and can clearly capture the license plate information displayed on the surface of the license plate N, which is oriented on the road surface and extends in the up-down direction (±Z direction), from the camera 3 arranged under the road surface. Since the vehicle information imaging device 1 captures the license plate information clearly and without distortion, the license plate recognition process in the downstream processing device (computer) is performed correctly. As described above, by using the vehicle information imaging device 1 according to this embodiment, the license plate information displayed on the license plate N can be correctly read from under the road surface, even without providing a window member protruding from the road surface 11.

[0036] As described above, since there is no window member protruding from the road surface, no large vibration occurs when vehicle A rides over a window member. This prevents the camera 3 from going out of focus, and prevents a decrease in the quality of the image captured by the camera 3. Also, it is possible to suppress breakdowns of the camera 3 due to vibrations caused by vehicle A.

[0037] Furthermore, the vehicle information imaging device 1 according to this embodiment is provided with a folding mirror 5 that guides the image of the license plate N reflected on the free curved surface mirror 4 to the camera 3 arranged below it. According to this configuration, the arrangement space for the camera 3 can be provided further below the free-form surface mirror 4. Then, since the arrangement space for the camera 3 is secured below the free-form surface mirror 4, the degree of freedom in the arrangement position of the free-form surface mirror 4 can be increased accordingly. This makes it possible to arrange the free-form surface mirror 4 closer to the transparent reinforcing plate 2 that is provided flat against the road surface 11, and allows the photographing object of the vehicle A, such as the license plate N or tires T, to be captured at a close distance. Therefore, the image captured by the camera 3 becomes clearer, and a highly accurate image can be captured.

[0038] Furthermore, according to the vehicle information imaging device 1 of this embodiment, the housing 6 that houses the camera 3 is fixed to the road surface 11 via the cushioning material 64, so that vibrations of the vehicle A traveling on the road surface 11 are absorbed by the cushioning material 64 and are less likely to be transmitted to the housing 6. Therefore, the influence of vibrations of the road surface 11 on the camera 3 and the free-form surface mirror 4 housed in the housing 6 can be kept small.

[0039] Furthermore, in the vehicle information imaging device 1 according to this embodiment, the camera 3 is disposed in the center of the lane width direction (±Y direction) to capture an image of the license plate N provided in front of and behind the vehicle A. The upper surface 2a of the transparent reinforcing plate 2 provided on the road surface 11 is disposed in a flat state with respect to the road surface 11. Therefore, even if the camera 3 is disposed in the center of the lane width direction (±Y direction), vibrations generated when the vehicle A travels on the transparent reinforcing plate 2 are reduced, and the influence of the vibrations of the road surface 11 on the camera 3 and the free curved surface mirror 4 can be kept small.

[0040] In the vehicle information imaging device 1 according to the present embodiment described above, the influence of vibrations on the camera 3 can be reduced.

[0041] <Second embodiment> Next, a vehicle information imaging device according to a second embodiment will be described with reference to Figures 5 to 7. Note that components having the same functions as those in the first embodiment described above are given the same reference numerals, and detailed descriptions of these components will be omitted to avoid duplication.

[0042] (Overall configuration of vehicle information imaging device) Fig. 5 is a second plan view of the overall configuration in which the vehicle information imaging device is provided on a road surface, as viewed from above. Fig. 6 is a side view showing an overall outline of the vehicle information imaging device. Fig. 7 is a diagram showing an example of an image captured of a tire installation state.

[0043] 5 and 6, the vehicle information imaging device 1 according to the second embodiment recognizes tires T of a vehicle A traveling on a lane L as an object to be photographed. The vehicle information imaging device 1 photographs the tires T of the vehicle A from the sides in the lane width direction (±Y direction) with a camera 3 and recognizes the tires T of the vehicle A. Then, the tires T are detected from the image photographed by the camera 3, making it possible to determine the number of axles of the vehicle A.

[0044] The vehicle information imaging device 1 is disposed on a boundary line La between each of the lanes L. Note that the boundary line La is, for example, a white or yellow line displayed on the road surface 11. In the present embodiment shown in FIG. 5, there are four lanes, and five boundary lines La are provided. The vehicle information imaging devices 1 are arranged at the same position in the lane direction (±X direction). At the three boundary lines La in the center of the lane width direction (±Y direction), a pair of vehicle information imaging devices 1 are provided, one of which faces one side (+Y direction) of the lane width direction (±Y direction) and the other of which faces the other side (-Y direction) of the lane width direction (±Y direction). According to this configuration, the tires T of the vehicle A traveling on each lane L are photographed by the cameras 3 from both sides (+Y direction and -Y direction) of the lane width direction (±Y direction).

[0045] 6, the vehicle information imaging device 1 has a configuration similar to that of the device for imaging the license plate N used in the first embodiment. That is, the vehicle information imaging device 1 includes a transparent reinforcing plate 2 (transparent member) having an upper surface 2a that is placed in a flat state with respect to a road surface 11, a camera 3 installed below the transparent reinforcing plate 2, a free-form surface mirror 4 that is provided so that the focal point of the camera 3 is uniformly aligned with the tire T in the height direction, and a folding mirror 5 that further reflects the image of the tire T reflected on the free-form surface mirror 4 toward the camera 3.

[0046] The vehicle information imaging device 1 performs imaging using the camera 3 in response to the ON / OFF of a vehicle detector (not shown) that detects the vehicle A entering and leaving a predetermined position in the lane direction. The vehicle detector is installed above each lane L, for example, via a gantry.

[0047] The vehicle information imaging device 1 captures an image D (see FIG. 7) including tires T of the vehicle A from the side of the vehicle A traveling on the lane L. The vehicle information imaging device 1 detects the tires T of the vehicle A by performing image processing on the captured image D of the tires T shown in FIG. 7, and counts the number of axles of the vehicle A from the number of detected tires T. In this case, for example, a processing device (computer) acquires the image D and performs processing to recognize the tires T from the acquired image D.

[0048] Furthermore, according to the vehicle information imaging device 1 of this embodiment, the side of the vehicle A can be photographed at close range, so that it is possible to determine whether the tire T is on the ground (lift axle) from the photographed image D. Note that FIG. 7 shows a state in which one tire T1 (the +X direction side) is on the ground and the other tire T2 (the -X direction side) is lifted from the road surface 11. Here, when photographing the side of the vehicle using a normal roadside camera and trying to determine the number of axles, it is difficult to accurately determine whether each tire is on the ground (whether to count as the number of axles) from the side image because the distance between the roadside camera and the vehicle is far. In contrast, according to the vehicle information imaging device 1 of this embodiment, it is possible to accurately determine whether each tire is on the ground and correctly count the number of axles.

[0049] (Action and effect) As described above, in the vehicle information imaging device 1 according to the second embodiment, the camera 3 is disposed on the side of the lane, and the tire T of the vehicle A can be photographed from the side. The upper surface 2a of the transparent reinforcing plate 2 provided on the road surface 11 is disposed in a flat state with respect to the road surface 11. Therefore, even if the camera 3 is disposed on the side of the lane, the vibration generated when the vehicle A runs on the transparent reinforcing plate 2 is reduced, and the influence of the vibration of the road surface 11 on the camera 3 and the free-form surface mirror 4 can be suppressed to a small extent. In addition, since the side of the running vehicle can be photographed at close range, it is possible to obtain a clear image that can determine whether the lift axle function is enabled (i.e., whether the tire T is on the ground).

[0050] Although each embodiment of the vehicle information imaging device has been described above, the present disclosure is not limited to the above-described embodiments and can be modified as appropriate without departing from the spirit of the present disclosure.

[0051] For example, although the present embodiment is configured with the folding mirror 5, it is also possible to omit the folding mirror 5. In this case, for example, a camera 3 facing diagonally downward is installed at a position diagonally above the free-form surface mirror 4, and the image reflected by the free-form surface mirror 4 is directly captured.

[0052] In addition, in the above-described embodiment, one vehicle information imaging device 1 is configured to have one camera 3 and one free-form surface mirror 4 corresponding to the camera 3, but there may be a plurality of cameras 3 and free-form surface mirrors 4. For example, two cameras 3 and two free-form surface mirrors 4 with different shooting directions may be provided on the housing 6.

[0053] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described embodiments may be combined as appropriate.

[0054] <Additional Notes> The vehicle information imaging device according to the above-described embodiment can be understood, for example, as follows.

[0055] (1) According to the first aspect, the vehicle information imaging device 1 is a vehicle information imaging device that is embedded in a road surface 11 and is used to recognize an object to be photographed (number plate N, tires T) of a vehicle A traveling on the road surface 11, and is equipped with a transparent reinforcing plate 2 having an upper surface 2a that is placed flat against the road surface 11, a camera 3 installed below the transparent reinforcing plate 2, and a free-form surface mirror 4 that is arranged so that the focus of the camera 3 is uniformly aligned in the height direction with respect to the object to be photographed.

[0056] In this way, the upper surface 2a of the transparent reinforcing plate 2 is arranged flat and without irregularities with respect to the road surface 11, and the camera 3 is installed below the transparent reinforcing plate 2. The free-form surface mirror 4 is provided so that the camera 3 is uniformly focused in the height direction on, for example, the license plate N, which is the object to be photographed. With this configuration, the camera 3 is not directly stepped on by the traveling vehicle A, and the influence of vibrations on the camera 3 can be reduced. Furthermore, since there is no window member protruding from the road surface, there is no large vibration caused when the vehicle A runs over the window member. Therefore, it is possible to prevent the focus of the camera 3 from being shifted and prevent a decrease in the quality of the image captured by the camera 3, and to suppress a breakdown of the camera 3 due to vibrations caused by the vehicle A.

[0057] (2) According to the second aspect, a folding mirror 5 is provided which reflects the image of the object to be photographed (license plate N, tire T) reflected on the free-form surface mirror 4 toward the camera 3, and the camera 3 is positioned so as to be able to photograph the image of the free-form surface mirror 4 reflected on the folding mirror 5.

[0058] In this way, the folding mirror 5 is positioned opposite the free-form surface mirror 4, and is therefore disposed above (in the +Z direction) the free-form surface mirror 4. That is, the camera 3 is disposed below (in the -Z direction) the folding mirror 5. This allows the camera 3 to be disposed below the free-form surface mirror 4, and therefore the free-form surface mirror 4 can be disposed without considering the space required for disposing the camera 3. That is, the free-form surface mirror 4 can be disposed close to the transparent reinforcing plate 2 that is provided flat against the road surface 11, and can capture the subject of the vehicle A, such as the license plate N or tires T, at a close distance. Therefore, the image captured by the camera 3 becomes clear, and a highly accurate image can be captured.

[0059] (3) According to the third aspect, the camera 3 is housed in a housing 6 that is provided against the road surface 11 via a buffer material 64 .

[0060] In this way, the housing 6 that houses the camera 3 is fixed to the road surface 11 via the cushioning material 64, so that the vibrations of the vehicle A traveling on the road surface 11 are absorbed by the cushioning material 64 and are not easily transmitted to the housing 6. Therefore, the influence of the vibrations of the road surface 11 on the camera 3 and the free-form surface mirror 4 housed in the housing 6 can be kept small.

[0061] (4) According to the fourth aspect, the object to be photographed is the license plate N of a vehicle A traveling on a lane L, and the camera 3 is provided in the center of the lane L in the lane width direction (±Y direction).

[0062] In this way, the camera 3 can be placed in the center of the lane to capture images of the license plates N provided in front of and behind the vehicle A. The upper surface 2a of the transparent reinforcing plate 2 provided on the road surface 11 is placed in a flat state with respect to the road surface 11. Therefore, even if the camera 3 is placed in the center of the lane, vibrations that occur when the vehicle A runs on the transparent reinforcing plate 2 are reduced, and the effects of vibrations of the road surface 11 on the camera 3 and the free-form surface mirror 4 can be kept small.

[0063] (5) According to the fifth aspect, the object to be photographed is a tire T of a vehicle A traveling on a lane L, and the camera 3 is provided on the side of the lane L in the lane width direction (±Y direction).

[0064] In this way, the camera 3 can be disposed laterally in the lane width direction (±Y direction) to capture an image of the tire T of the vehicle A from the side. The upper surface 2a of the transparent reinforcing plate 2 provided on the road surface 11 is disposed in a flat state with respect to the road surface 11. Therefore, even if the camera 3 is disposed laterally in the lane width direction (±Y direction), vibrations that occur when the vehicle A travels on the transparent reinforcing plate 2 are reduced, and the influence of vibrations of the road surface 11 on the camera 3 and the free-form surface mirror 4 can be kept small. In this case, the side of the vehicle A can be photographed at close range, and the photographed image D can be used to determine whether the tire T is on the ground (lift axle). [Explanation of symbols]

[0065] 1 Vehicle information imaging device 2 Transparent reinforced plate (transparent material) 2a Top side 3. Camera 4 Freeform mirror 4a Concave surface 5. Folding mirror 6. Chassis 20 Fixture N License plate (subject of photography) T Tire (subject of photography)

Claims

1. A vehicle information imaging device that is embedded in a road surface and is used to recognize an object to be photographed by a vehicle traveling on the road surface, A transparent member having an upper surface that is placed flat against the road surface; A camera installed below the transparent member; a free-form surface mirror provided so that the focal point of the camera is uniformly aligned in a height direction with respect to the object to be photographed; A vehicle information imaging device comprising:

2. a folding mirror is provided to reflect the image of the object to be photographed reflected on the free-form surface mirror toward the camera; The vehicle information imaging device according to claim 1 , wherein the camera is disposed so as to be able to capture an image of the free-form surface mirror reflected in the folding mirror.

3. 3. The vehicle information imaging device according to claim 1, wherein the camera is accommodated in a housing that is provided with a buffer material in contact with the road surface.

4. the photographed object is a license plate of the vehicle traveling in a lane, The vehicle information imaging device according to claim 1 , wherein the camera is provided at a center of the lane in a width direction of the lane.

5. the photographed object is a tire of the vehicle traveling on a lane, The vehicle information imaging device according to claim 1 , wherein the camera is provided on a side of the lane in a width direction of the lane.

Images