JP2018125743A - On-vehicle imaging apparatus and reflection suppression method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle imaging apparatus and a reflection suppression method capable of suppressing reflection.SOLUTION: An on-vehicle imaging apparatus 1 according to one embodiment of this invention comprises: a camera 10 for taking an image; and an optical member 20 arranged between a windshield 30 inclined so as to cover the camera 10 therewith and the camera 10 and comprising an incident surface 21 opposing the windshield 30 and an outgoing surface 22 opposing the camera 10. The camera 10 takes an image of the outside of a vehicle through the windshield 30 and the optical member 20. The incident surface 21 of the optical member 20 is in contact with the windshield 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an in-vehicle imaging device and a reflection suppression method, and for example, when an image outside a vehicle is captured through a windshield, the in-vehicle that suppresses reflection of light from the inside of the vehicle to the windshield and reflection in the image. The present invention relates to a photographing apparatus and a reflection suppression method.

  Drive recorders that are mounted on vehicles and record video are widely used. The drive recorder is attached, for example, via a bracket or the like above the windshield of the vehicle. Patent Document 1 discloses a drive recorder that is attached to a windshield of a vehicle using a mounting bracket.

JP 2011-109634 A

  Many drive recorders, such as the drive recorder of patent document 1, are installed close to the windshield of a vehicle, and image | photograph the exterior of a vehicle through a windshield. Many windshields are installed on the inside of the car. For this reason, in-vehicle equipment such as a dashboard may be reflected on the windshield and reflected on the drive recorder.

  Such a reflection becomes conspicuous when sunlight enters a car or when it is illuminated by a night street lamp. If reflection occurs during shooting with a drive recorder, the quality of the recorded video is degraded.

  An object of this invention is to provide the vehicle-mounted imaging device and the reflection suppression method which can suppress a reflection in view of the said problem.

  Accordingly, the present invention provides a camera that captures an image, a windshield that is inclined so as to cover the camera, and an optical member that is disposed between the camera, an incident surface that faces the windshield, and the camera And the optical member having an emission surface opposed to the camera, wherein the camera provides an in-vehicle imaging device that images the outside of the vehicle through the windshield and the optical member.

  According to the present invention, an in-vehicle photographing device and a reflection suppression method capable of suppressing reflection are provided.

It is the side view which illustrated the vehicle-mounted imaging device concerning Embodiment 1. FIG. 3 is a side view illustrating the path of light from a subject to be photographed in the in-vehicle photographing device according to the first embodiment. It is the side view which illustrated the reflection which occurs in a camera by reflection by a windshield in the in-vehicle photography device concerning a comparative example. FIG. 5 is a flowchart illustrating a reflection suppression method for suppressing reflection in the in-vehicle imaging device according to the first embodiment. FIG. 6 is a side view illustrating an in-vehicle imaging device according to a second embodiment. FIG. 6 is a side view illustrating an in-vehicle imaging device according to a third embodiment. It is the figure which illustrated reference data of a picture. It is the figure which illustrated the simulation result of the image image | photographed with the vehicle-mounted imaging device which concerns on Embodiment 3, and has shown the video data before a process part processes.

(Embodiment 1)
Hereinafter, the vehicle-mounted imaging device according to the first embodiment will be described with reference to the drawings. First, the configuration of the in-vehicle imaging device will be described.

<Configuration of in-vehicle imaging device>
FIG. 1 is a side view illustrating an in-vehicle imaging device 1 according to the first embodiment. As shown in FIG. 1, the in-vehicle imaging device 1 includes a camera 10 and an optical member 20. The in-vehicle photographing device 1 is a device that is disposed inside a vehicle such as an automobile and photographs the outside of the vehicle through the windshield 30. The in-vehicle photographing device 1 is used as a drive recorder, for example. The camera 10 and the optical member 20 may be separated from each other, or the optical member 20 may be attached on the optical axis 13 of the camera 10.

  The camera 10 captures an image. The camera 10 has a housing 11 and includes an optical system such as an imaging lens 12 and an imaging element. An imaging lens 12 is disposed at one end of the housing 11. The camera 10 has an optical axis 13 of an optical system including an imaging lens 12. The optical system such as the imaging lens 12 and the imaging element is arranged with the optical axis 13 as a reference. The camera 10 is inclined from the horizontal so that the imaging lens 12 side is upward. Therefore, the optical axis 13 of the camera 10 is inclined from the horizontal so that the imaging lens 12 side is upward. An optical member 20 and a windshield 30 are arranged in the direction in which the optical axis 13 of the camera 10 extends.

  The camera 10 may include a display unit and a recording unit. In the case where the camera 10 includes a display unit and a recording unit, the display unit and the recording unit may be separated from the housing 11 and arranged at different locations. Further, the display unit and the recording unit may be connected to the housing 11 by a signal line or wirelessly. The camera 10 is attached to a predetermined position of the vehicle by an attachment portion such as a bracket. For example, the camera 10 is attached above the windshield 30.

  The windshield 30 is, for example, a windshield of a vehicle, and is a transparent member that prevents wind from entering the vehicle from the outside of the vehicle. The inner surface of the windshield 30 is referred to as an inner surface 31, and the outer surface of the vehicle is referred to as an outer surface 32. The windshield 30 is disposed to be inclined toward the vehicle interior side. The windshield 30 is disposed so as to face the optical axis 13 of the camera 10 and is inclined so as to cover the camera 10. With this arrangement, the camera 10 can take an image of the outside of the vehicle through the windshield 30. For example, by attaching the camera 10 above the inner surface 31 of the windshield 30, the camera 10 captures an image outside the vehicle through the windshield 30.

  The optical member 20 is disposed between the windshield 30 and the camera 10. The optical member 20 is a transparent member having a refractive index different from that of air. Therefore, when light enters the optical member 20 from the air and when light exits from the optical member 20 into the air, the light is refracted or reflected at the interface of the optical member 20. The optical member 20 is a prism, for example. The optical member 20 includes, for example, glass, crystal or the like as a material. The optical member 20 may include the same material as that included in the windshield 30. Preferably, the optical member 20 may be formed of the same material as the windshield 30. In addition, the material of the optical member 20 is not restricted to these.

  The optical member 20 has a prismatic shape, for example, and has a plurality of surfaces constituting the outer shape. The optical member 20 disposed between the windshield 30 and the camera 10 has an incident surface 21 facing the windshield 30 and an exit surface 22 facing the camera 10. The optical member 20 has a lower surface 23 facing downward. Note that the optical member 20 may have a shape other than a prism, such as a cylinder.

  For example, the incident surface 21 is disposed with a space from the inner surface 31 of the windshield 30. The incident surface 21 is a flat surface, for example. In the inner surface 31 of the windshield 30, the local part which the entrance plane 21 of the optical member 20 opposes is a substantially plane. The incident surface 21 is a surface substantially parallel to the inner surface 31 of the windshield 30. If the camera 10 can capture images through the incident surface 21, the incident surface 21 may be inclined with respect to the inner surface 31 of the windshield 30.

  The exit surface 22 is inclined with respect to the entrance surface 21. The emission surface 22 is, for example, a flat surface. Light incident on the exit surface 22 from the direction of the camera 10 or the dashboard may be reflected into the angle of view 14 of the camera 10. At this time, the arrangement of the optical member 20 or the optical member 20 is adjusted so that the reflectance of the light reflected on the emission surface 22 and incident on the camera 10 is 10% or less over the entire field angle 14 of the camera 10. The inclination of the entrance surface 21 and the exit surface 22 is determined. As a result, the reflection on the light exit surface 22 of the light reflected from the light exit surface 22 of the optical member 20 from the rear or the dashboard direction of the camera 10 becomes 10% or less, thereby minimizing reflection. Limit. Specifically, for example, the optical axis 13 of the camera 10 is orthogonal to the emission surface 22. Thereby, the reflectance at the emission surface 22 can be 10% or less over the entire field angle 14 of the camera 10. Note that the method of setting the reflectance to 10% or less is not limited to this.

  Further, the light emitted from the emission surface 22 includes light within the angle of view 14 of the camera 10. Further, light within the angle of view 14 of the camera 10 that exits from the exit surface 22 is incident on the exit surface 22 from the entrance surface 21. The reflectance at the exit surface 22 when light within the angle of view 14 of the camera 10 enters the exit surface 22 from the entrance surface 21 is, for example, 10% or less. As a result, the amount of light reaching the camera 10 can be increased, and the quality of the captured video can be improved.

  A part of the light 42 incident on the windshield 30 from the horizontal direction in front of the vehicle and passing through the windshield 30 and entering the incident surface 21 of the optical member 20 is along the optical axis 13 of the camera 10 from the emission surface 22. To reach the camera 10. The light 42 passing through such an optical path is a photographing center taken by the camera 10.

  The lower surface 23 of the optical member 20 faces downward. The lower surface 23 is a flat surface, for example. The lower surface 23 may be black so as to shield light, or a light shielding film may be formed. The lower surface 23 is formed at a position that does not block light from a subject to be photographed outside the vehicle. On the other hand, the lower surface 23 is formed at a position where a part of light 46 from equipment such as a dashboard reflected by the windshield 30 is incident.

  Next, the operation of the in-vehicle imaging device 1 will be described. As an operation of the in-vehicle imaging device 1, first, the path of light from the imaging target will be described. Next, as a comparative example, the path of light that causes reflection in the camera 10 will be described. Thereafter, a method for suppressing reflection will be described in comparison with the comparative example. First, the path of light from the object to be imaged will be described.

<Light from the subject>
FIG. 2 is a side view illustrating the path of light from the imaging target in the in-vehicle imaging device 1 according to the first embodiment. As shown in FIG. 2, the camera 10 disposed in the vehicle photographs the outside of the vehicle through the windshield 30 and the optical member 20. An optical member 20 having an incident surface 21 facing the windshield 30 and an exit surface 22 facing the camera 10 is disposed between the windshield 30 and the camera 10.

  Light from a subject to be photographed outside the vehicle is incident on the outer surface 32 of the windshield 30. Here, a description will be given using light 41 as light from a subject to be photographed outside the vehicle, which is taken by the camera 10. The light 41 from the object to be photographed is incident at the incident angle θ11 on the outer surface 32 that is the interface between the air and the windshield 30 and reaches the inside of the windshield 30 at the refraction angle ψ11. In this case, according to Snell's law, the refractive index n11 is expressed by the following equation (1).

  n11 = (sin θ11) / (sinψ11) (1)

  Then, the light 41 that has reached the inside of the windshield 30 reaches the inner surface 31 of the windshield 30. On the inner surface 31 of the windshield 30, the light 41 from the subject is incident at an incident angle θ12 and enters the vehicle at a refraction angle ψ12. In this case, according to Snell's law, the refractive index n12 is expressed by the following equation (2).

  n12 = (sin θ12) / (sinφ12) (2)

  Here, for example, θ11 = ψ12 and ψ11 = θ12. Light 41 emitted from the inner surface 31 of the windshield 30 into the vehicle enters the incident surface 21 of the optical member 20. On the incident surface 21 of the optical member 20, the light 41 from the subject is incident at an incident angle θ13 and reaches the inside of the optical member 20 at a refraction angle ψ13. In this case, the refractive index n13 is expressed by the following equation (3).

  n13 = (sin θ13) / (sinφ13) (3)

  Then, the light 41 that has reached the inside of the optical member 20 reaches the emission surface 22 of the optical member 20. On the exit surface 22, the light 41 from the subject is incident at an incident angle θ <b> 14 and exits from the optical member 20 at a refraction angle ψ <b> 14. In this case, the refractive index n14 is expressed by the following equation (4) according to Snell's law.

  n14 = (sin θ14) / (sinφ14) (2)

  The light 41 emitted from the emission surface 22 of the optical member 20 enters the imaging lens 12 of the camera 10 and forms an image on the imaging element of the camera 10. Similarly, with respect to the other light within the angle of view 14 of the camera 10, the light from the subject is incident on the imaging lens 12 of the camera 10 through the windshield 30 and the optical member 20, and on the imaging element of the camera 10. To form an image. In this way, the in-vehicle photographing device 1 can photograph the outside of the vehicle with the camera through the windshield 30 and the optical member 20.

  As the distance between the exit surface 22 of the optical member 20 and the camera 10 increases, the area of the exit surface 22 included in the angle of view 14 of the camera 10 increases. Therefore, in that case, it is necessary to increase the size of the optical member 20. Therefore, the size of the optical member 20 can be reduced by reducing the distance between the emission surface 22 of the optical member 20 and the camera 10.

  If the inner surface 31 and the outer surface 32 of the windshield 30 are parallel and the light within the angle of view 14 of the camera 10 includes light 43 incident on the outer surface 32 of the windshield 30 at an incident angle of 0 °, the light 43 Advances from the outer surface 32 of the windshield 30 to the inside of the windshield 30 at an exit angle of 0 °, and enters the inner surface 31 of the windshield 30 at an incident angle of 0 °. Then, the light is emitted from the inner surface 31 of the windshield 30 at an emission angle of 0 °.

  When the optical axis 13 of the camera 10 is set so as to be orthogonal to the emission surface 22 of the optical member 20, the light 42 emitted from the emission surface 22 along the optical axis 13 and reaching the camera 10 is incident on the incident surface 21. To the light exit surface 22 perpendicularly. The tilt of the camera 10 is set so that the light 42 incident perpendicularly to the exit surface 22 from the incident surface 21 becomes the light 42 incident on the windshield 30 from the horizontal direction. Thereby, the horizontal direction outside the vehicle can be set as the imaging center.

  The reflectivity can be defined by the ratio of the amount (intensity) of the reflected light beam to the amount (intensity) of the incident light beam at the interface of the optical member 20. For example, the reflectance at the exit surface 22 when light having the maximum view angle within the view angle 14 of the camera 10 is incident on the exit surface 22 from the object to be reflected is 10% or less. Thereby, the reflection of light from the unintended direction on the emission surface 22 can be reduced, and the amount of reflected light from the rear of the dashboard or the camera 10 can be suppressed. For example, when the material of the optical member 20 is glass, the reflectance can be 10% or less by setting the incident angle to 50 ° or less. In consideration of the material of the optical member 20, the angle of view 14 of the camera 10 and the angle between the exit surface 22 and the optical axis 13 of the camera 10, the reflectance is set to 10% or less. Specifically, for example, the optical axis 13 of the camera 10 is orthogonal to the emission surface 22. Thereby, the reflectance at the emission surface 22 can be 10% or less over the entire area of the field angle 14 of the camera 10 including the maximum field angle. In addition, the method of making a reflectance into 10% or less is not restricted to this.

  The reflectance can be defined by the ratio of the amount (intensity) of the reflected light beam to the amount (intensity) of the incident light beam at the interface of the windshield 30 or the optical member 20. For example, the reflectance at the exit surface 22 when light having the maximum view angle within the view angle 14 of the camera 10 enters the exit surface 22 from the entrance surface 21 is 10% or less. As a result, the amount of light reaching the camera 10 can be increased, and the quality of the captured video can be improved. For example, when the material of the optical member 20 is glass, the reflectance can be 10% or less by setting the incident angle to 50 ° or less. In consideration of the material of the optical member 20, the angle of view 14 of the camera 10 and the angle between the exit surface 22 and the optical axis 13 of the camera 10, the reflectance is set to 10% or less.

<Light that causes reflection>
Next, as a comparative example, it will be described that light from the vehicle is reflected on the inner surface 31 of the inclined windshield 30 and reflected on the camera 10. FIG. 3 is a side view illustrating reflections that occur in the camera 10 due to reflection by the windshield 30 in the in-vehicle imaging device 100 according to the comparative example.

  As shown in FIG. 3, the in-vehicle imaging device 100 according to the comparative example has a configuration excluding the optical member 20. The camera 10 of the in-vehicle imaging device 100 captures an image outside the vehicle through the windshield 30. Light from a subject to be photographed outside the vehicle is incident on the outer surface 32 of the windshield 30. Here, a description will be given using light 44 as light from a subject to be photographed outside the vehicle and within the angle of view 14 of the camera 10. The light 44 from the subject is incident on the outer surface 32 of the windshield 30 at an incident angle θ21 and reaches the inside of the windshield 30 at a refraction angle ψ21. In this case, according to Snell's law, the refractive index n21 is expressed by the following equation (5).

  n21 = (sin θ21) / (sinφ21) (5)

  Then, the light 44 that has reached the inside of the windshield 30 reaches the inner surface 31 of the windshield 30. On the inner surface 31 of the windshield 30, the light 44 from the subject is incident at an incident angle θ22 and enters the vehicle at a refraction angle ψ22. In this case, the refractive index n22 is expressed by the following equation (6) from Snell's law.

  n22 = (sin θ22) / (sinφ22) (6)

  Here, for example, θ21 = ψ22 and ψ21 = θ22. Light 44 emitted from the inner surface 31 of the windshield 30 into the vehicle enters the imaging lens 12 of the camera 10 and forms an image on the imaging element of the camera 10. Similarly, with respect to the other light within the angle of view 14 of the camera 10, the light from the subject is incident on the imaging lens 12 of the camera 10 through the windshield 30 and is imaged on the imaging element of the camera 10. . In this way, the in-vehicle imaging device 100 can capture an image outside the vehicle through the windshield 30 with the camera.

  Since the optical member 20 is not provided, the light 45 from the horizontal direction outside the vehicle travels in the horizontal direction even after passing through the windshield 30. Therefore, by setting the optical axis 13 of the camera 10 in the horizontal direction, the horizontal direction outside the vehicle can be set as the photographing center.

  In the in-vehicle imaging device 100 according to the comparative example, the reflection that the light from the interior equipment such as the dashboard is reflected on the windshield 30 and reflected on the camera 10 occurs. As shown in FIG. 3, the light 46 from the vehicle is reflected by the windshield 30 and reflected on the camera 10. Specifically, the light 46 from the vehicle reaches the inner surface 31 of the windshield 30. On the inner surface 31 of the windshield 30, the light 46 from the vehicle enters at an incident angle θ31 and reflects at a reflection angle φ31. Here, for example, θ31 = φ31. The light 46 reflected by the inner surface 31 of the windshield 30 enters the imaging lens 12 of the camera 10 and is reflected on the camera 10.

  Light reflected from the camera 10 is reflected by the region 33 included in the angle of view 14 of the camera 10 on the inner surface 31 of the windshield 30 from the inside of the vehicle. In the drawing, the region 33 is indicated by a one-dot chain line. In the comparative example, since there is nothing that blocks the reflected light reflected by the area 33 between the area 33 and the camera 10, the light 46 is reflected by the area 33 and reflected on the camera 10.

  Further, the optical axis 13 of the camera 10 is set to the horizontal direction in order to set the horizontal direction outside the vehicle as the imaging center. Then, since the incident angle from the dashboard or the like to the inner surface 31 of the windshield 30 is large at the lower end of the image of the camera 10, the amount of light reflected greatly increases. Note that the amount of light reflected on the camera 10 may increase when the angle of view of the camera 10 is large, when the reflectance of the region 33 is high, or when the incident angle at the region 33 is large.

  Thus, in the vehicle-mounted imaging device 100 according to the comparative example, it is possible to suppress the reflection of light reflected from the vehicle interior and reflected on the camera 10 onto the windshield 30 that is inclined so as to cover the camera 10. Can not.

<Reflection suppression method>
Next, a reflection suppression method using the vehicle-mounted imaging device 1 according to the first embodiment will be described while comparing with a comparative example. FIG. 4 is a flowchart illustrating a reflection suppression method for suppressing reflection in the in-vehicle imaging device 1 according to the first embodiment.

  First, as shown in step S <b> 11 of FIG. 4 and FIG. 1, the optical member 20 having the entrance surface 21 and the exit surface 22 is arranged such that the entrance surface 21 faces the windshield 30 and the exit surface 22 faces the camera 10. Next, it is arranged between the windshield 30 and the camera 10.

  Next, as shown in step S <b> 12 of FIG. 4 and FIG. 1, an image outside the vehicle is taken by the camera 10 through the windshield 30 and the optical member 20. With such a configuration, the light 41 to 43 to be imaged enters from the outer surface 32 of the windshield 30, passes through the inside of the windshield 30, and exits from the inner surface 31 of the windshield 30. Lights 41 to 43 within the angle of view 14 of the camera 10 emitted from the inner surface 31 of the windshield 30 reach the imaging lens 12 of the camera. Thereby, it is possible to shoot a video to be shot.

  On the other hand, light 46 reflected from the region 33 included in the angle of view 14 of the camera 10 on the inner surface 31 of the windshield 30 out of the light emitted from the interior of the vehicle, such as the dashboard in the vehicle, is the lower surface 23 of the optical member 20. Is incident on. The light 46 incident on the lower surface 23 of the optical member 20 is refracted by the lower surface 23 of the optical member 20 and travels in a direction different from that of the camera 10. Alternatively, the light is blocked by the light blocking function formed on the lower surface 23.

  Thus, in the present embodiment, the optical member 20 is disposed between the windshield 30 and the camera 10. Therefore, the light reflected by the area 33 included in the angle of view 14 of the camera 10 on the inner surface 31 of the windshield 30 can be prevented from reaching the camera 10, and reflection can be suppressed.

  The outside of the vehicle is photographed through an optical member 20 such as a prism that refracts light. Therefore, the optical axis 13 of the camera 10 can be installed perpendicular to the emission surface 22 of the optical member 20 in order to set the horizontal direction as the imaging center. Thereby, the reflectance of reflection can be reduced. Therefore, the amount of light that causes reflection can be reduced, and reflection can be suppressed.

  In order to reduce the reflection of the light 46 from inside the vehicle such as a dashboard, the inclination of the windshield 30 can be changed so that the axis of symmetry between the dashboard and the camera 10 is not perpendicular to the inner surface 31 of the windshield 30. However, the inclination of the windshield 30 cannot be changed. Therefore, by passing the optical member 20 such as a prism, the horizontal direction can be set as the photographing center while the optical axis 13 of the camera 10 is directed upward.

Next, the effect of this embodiment will be described.
In the present embodiment, the optical member 20 is disposed between the windshield 30 and the camera 10. Thereby, it can suppress that the light 46 from the inside of the vehicle reflected by the windshield 30 is reflected on the camera 10 while photographing the outside of the vehicle.

  Further, the optical axis 13 of the camera 10 can be installed perpendicularly to the emission surface 22 of the optical member 20 in order to photograph the outside of the vehicle through the optical member 20 where light is refracted. Thereby, the reflectance which the light 46 from the vehicle used as a reflection reflects can be reduced, and a reflection can be suppressed.

  The incident surface 21 of the optical member 20 is substantially parallel to the windshield 30, and the exit surface 22 is orthogonal to the optical axis of the camera 10. This facilitates the setting with the horizontal direction as the imaging center.

  The reflectance at the exit surface 22 of light that is reflected by the exit surface 22 and enters the angle of view 14 of the camera 10 to cause reflection is 10% or less. Thereby, the reflection by the light from the back of the camera 10, a dashboard, etc. can be suppressed. Further, by setting the reflectance at the exit surface 22 of the optical member 20 at the maximum angle of view within the angle of view 14 of the camera 10 to 10% or less, the amount of light can be increased and the image quality can be improved. Moreover, even if the inclination of the windshield 30 changes slightly depending on the vehicle type, the reflectance remains within 10%, so that various types of vehicles can be supported.

(Embodiment 2)
<Attaching optical members>
Next, the vehicle-mounted imaging device 2 according to the second embodiment will be described. In the in-vehicle imaging device 2 of the present embodiment, the incident surface 21 of the optical member 20 is attached to the inner surface 31 of the windshield 30. FIG. 5 is a side view illustrating the vehicle-mounted imaging device 2 according to the second embodiment.

  As shown in FIG. 5, the in-vehicle imaging device 2 has the incident surface 21 of the optical member 20 attached to the inner surface 31 of the windshield 30, and the incident surface 21 of the optical member 20 is in contact with the windshield 30. Yes. Thereby, it can suppress that the light used as a reflection enters between between the windshield 30 and the entrance plane 21.

  When the incident surface 21 of the optical member 20 is attached to the inner surface 31 of the windshield 30, the inner surface 31 of the windshield 30 can be regarded as a substantially flat surface at a local portion where the incident surface 21 contacts. Therefore, contact can be made even when the incident surface 21 is a flat surface.

  Note that because of the curved shape of the inner surface 31 of the windshield 30, only the peripheral portion of the incident surface 21 having a planar shape is in contact with the inner surface 31 of the windshield 30, and there is a slight gap in the central portion of the incident surface 21. However, the effect on the reflection is small and it is sufficiently effective. Therefore, only the peripheral part may be contacted.

  Further, for example, when the inner surface 31 of the windshield 30 is curved, the shape of the incident surface 21 may be adjusted to fit the inner surface 31 of the windshield 30 and attached and contacted.

  The optical member 20 preferably includes the same material as that included in the windshield 30. The refractive index of the optical member 20 is preferably set to the same value as the refractive index of the windshield 30. When the windshield 30 and the optical member 20 are made of the same material, they are not refracted at the contact interface. Accordingly, the windshield 30 and the optical member 20 can be integrated to transmit light.

  For example, light 47 from the horizontal direction outside the vehicle is incident on the outer surface 32 of the windshield 30 at an incident angle θ41 and travels from the outer surface 32 at a refraction angle ψ41. Then, it passes through the optical member 20 and reaches the emission surface 22. Then, the light exits from the exit surface 22 and reaches the imaging lens 12 along the optical axis 13 of the camera 10.

  In the present embodiment, since the windshield 30 and the incident surface 21 are in contact with each other, the number of times of refraction can be reduced, and the optical path of light can be simplified. For example, the light 47 from the horizontal direction outside the vehicle can be easily aligned with the optical axis 13 of the camera 10 by setting the angle formed by the incident surface 21 and the exit surface 22 to the same angle as the refraction angle ψ41. That is, by making the optical axis 13 of the camera 10 orthogonal to the exit surface 22, the horizontal direction outside the vehicle can be set as the imaging center.

Next, the effect of this embodiment will be described.
In the in-vehicle imaging device 2 of the present embodiment, the incident surface 21 of the optical member 20 is in contact with the windshield 30, so that light that is reflected is incident between the windshield 30 and the incident surface 21. Can be suppressed.

  Further, the number of times of refraction can be reduced, and the optical path of light can be simplified. In particular, when the optical member 20 includes the same material as that included in the windshield 30, it is not refracted at the boundary surface. Therefore, the windshield 30 and the optical member 20 can be integrated to transmit light, and the optical axis 13 of the camera 10 can be easily aligned.

  Furthermore, since the windshield 30 and the optical member 20 can be integrated, the amount of reflection at the incident surface 21 can be reduced. Therefore, the amount of light can be increased and the quality of the video can be improved. Other configurations and effects are the same as those of the first embodiment.

(Embodiment 3)
<Distortion correction method>
A vehicle-mounted imaging device 3 according to Embodiment 3 will be described. The in-vehicle imaging device 3 includes a processing unit 50 that processes video data. FIG. 6 is a side view illustrating the in-vehicle imaging device 3 according to the third embodiment.

  As shown in FIG. 6, the in-vehicle imaging device 3 includes a processing unit 50 that processes video data captured by the camera 10. The processing unit 50 processes the distortion of the data of the video imaged by the camera 10 based on the video image acquired by the camera 10 by photographing the outside of the vehicle in advance through the optical member 20 or the distortion data calculated by the optical design software. .

  FIG. 7 is a diagram illustrating video reference data. As shown in FIG. 7, the reference data of the video is obtained by, for example, previously capturing reference lines 51 arranged at equal intervals in the vertical direction and the horizontal direction. In the state where the distortion is negligible, when the X mark 52 arranged at equal intervals in the vertical direction and the horizontal direction is photographed, an image in which the intersection of the reference line 51 and the X mark 52 are overlapped is obtained.

  FIG. 8 is a diagram illustrating a simulation result of a video shot by the in-vehicle shooting device 3 according to the third embodiment, and shows video data before the processing unit 50 processes. As shown in FIG. 8, when the X mark 52 arranged at equal intervals in the vertical direction and the horizontal direction is photographed by the in-vehicle photographing device 3, if the image is distorted, a part of the X mark 52 is displayed. The video does not overlap with the intersection of the reference lines 51. For example, as shown in FIG. 8, when an image is taken through an optical member 20 such as a prism, a difference in optical path length occurs between the upper part and the lower part, and the intersection of the X mark 52 and the reference line 51 in the peripheral part of the image. There is a large gap. The processing unit 50 of the in-vehicle imaging device 3 processes the distortion of the video data captured by the camera 10 based on the distortion data of the video obtained by the simulation acquired in advance as shown in FIG. Specifically, the distortion data in FIG. 8 is held as a table, and the distortion is corrected so as to return to the state in FIG. 7 based on the distortion data for the actually captured video.

Next, the effect of this embodiment will be described.
According to the in-vehicle photographing apparatus 3 according to the present embodiment, even if distortion is generated in an image obtained by photographing the outside of the vehicle through the optical member 20, the processing unit 50 processes the distortion, thereby suppressing deterioration in the image quality. can do. Other configurations and effects are the same as those of the first and second embodiments.

  As mentioned above, although Embodiment 1-3 was demonstrated, the structure which combined the structure of Embodiment 1-3 mutually is also contained in the scope of the technical idea demonstrated by this specification.

1, 2, 3, 100 In-vehicle imaging device 10 Camera 11 Housing 12 Imaging lens 13 Optical axis 14 Angle of view 20 Optical member 21 Incident surface 22 Emission surface 23 Lower surface 30 Windshield 31 Inner surface 32 Outer surface 33 Regions 41, 42, 43, 44, 45, 46, 47 Light 50 Processing unit 51 Reference line 52 X mark

Claims (9)

A camera for taking pictures,
An optical member disposed between the windshield inclined to cover the camera and the camera, the optical member having an entrance surface facing the windshield and an exit surface facing the camera;
With
The camera photographs the outside of the vehicle through the windshield and the optical member.
In-vehicle imaging device. The incident surface of the optical member is in contact with the windshield,
The in-vehicle imaging device according to claim 1. The optical member includes the same material as that included in the windshield,
The in-vehicle imaging device according to claim 1 or 2. The incident surface is substantially parallel to the vehicle inner surface of the windshield,
The exit surface is orthogonal to the optical axis of the camera;
The in-vehicle imaging device according to any one of claims 1 to 3. A processing unit for processing the video data;
The processing unit processes distortion of the data based on the distortion data of the video acquired in advance.
The vehicle-mounted imaging device according to any one of claims 1 to 4. The reflectance at the exit surface when light within the angle of view of the camera enters the exit surface from the entrance surface is 10% or less,
The in-vehicle imaging device according to any one of claims 1 to 5. The reflectance at the exit surface of the light that is reflected at the exit surface and enters the angle of view of the camera to cause reflection is 10% or less.
The in-vehicle photographing device according to any one of claims 1 to 6. A part of the light incident on the windshield from the horizontal direction outside the vehicle and incident on the incident surface through the windshield exits from the exit surface along the optical axis of the camera, and the camera To reach the
The in-vehicle imaging device according to any one of claims 1 to 7. A reflection control method that suppresses reflection of light from the interior of the windshield that is inclined so as to cover a camera that shoots an image, and reflected on the camera,
An optical member having an entrance surface and an exit surface is disposed between the windshield and the camera such that the entrance surface faces the windshield and the exit surface faces the camera,
The outside of the vehicle is photographed with the camera through the windshield and the optical member,
Reflection suppression method.

Images