JP6805854B2 - In-vehicle shooting device and reflection suppression method - Google Patents

Description

The present invention relates to an in-vehicle photographing device and a reflection suppressing method. For example, when an image of the outside of a vehicle is photographed through a windshield, the light from the inside of the vehicle is reflected by the windshield and is suppressed from being reflected in the image. The present invention relates to a photographing device and a reflection suppressing method.

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

Japanese Unexamined Patent Publication No. 2011-109634

Many drive recorders, such as the drive recorder of Patent Document 1, are installed close to the windshield of the vehicle and photograph the outside of the vehicle through the windshield. Most of the windshields are installed at an angle inside the car. For this reason, equipment in the vehicle such as a dashboard may be reflected on the windshield and reflected on the drive recorder.

Such reflections are noticeable when sunlight shines into the car or when illuminated by street lights at night. If glare occurs during shooting with a drive recorder, the quality of the recorded image will deteriorate.

In view of the above problems, an object of the present invention is to provide an in-vehicle photographing apparatus capable of suppressing reflection and a method for suppressing reflection.

Therefore, the present invention is an optical member arranged between a camera that captures an image, a windshield inclined so as to cover the camera, and the camera, and the incident surface facing the windshield and the camera. The camera comprises an optical member having an exit surface facing the windshield, and the camera provides an in-vehicle photographing device for photographing the outside of a vehicle through the windshield and the optical member.

INDUSTRIAL APPLICABILITY The present invention provides an in-vehicle photographing apparatus capable of suppressing reflection and a method for suppressing reflection.

It is a side view which illustrates the vehicle-mounted photographing apparatus which concerns on Embodiment 1. FIG. FIG. 5 is a side view illustrating the path of light from a photographing target in the vehicle-mounted photographing apparatus according to the first embodiment. It is a side view which illustrates the reflection generated in the camera by the reflection by a windshield in the vehicle-mounted photographing apparatus which concerns on a comparative example. It is a flowchart which illustrates the reflection suppression method which suppresses the reflection in the vehicle-mounted photographing apparatus which concerns on Embodiment 1. FIG. It is a side view which illustrates the vehicle-mounted photographing apparatus which concerns on Embodiment 2. FIG. It is a side view which illustrates the vehicle-mounted photographing apparatus which concerns on Embodiment 3. FIG. It is a figure which illustrated the reference data of a video. It is a figure exemplifying the simulation result of the image taken by the in-vehicle photographing apparatus which concerns on Embodiment 3, and shows the image data before processing by a processing unit.

(Embodiment 1)
Hereinafter, the in-vehicle photographing apparatus 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 the vehicle-mounted photographing apparatus 1 according to the first embodiment. As shown in FIG. 1, the in-vehicle photographing apparatus 1 includes a camera 10 and an optical member 20. The in-vehicle photographing device 1 is a device that is arranged inside a vehicle such as an automobile and photographs the outside of the vehicle through a windshield 30. The in-vehicle photographing device 1 is used as, for example, a drive recorder. The camera 10 and the optical member 20 may be separated from each other, or the optical member 20 may be mounted 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 image pickup lens 12 and an image pickup element inside. An imaging lens 12 is arranged at one end of the housing 11. The camera 10 has an optical axis 13 of an optical system including an image pickup lens 12. The optical system such as the image pickup lens 12 and the image pickup element is arranged with reference to the optical axis 13. The camera 10 is tilted from the horizontal so that the image pickup lens 12 side is upward. Therefore, the optical axis 13 of the camera 10 is tilted from the horizontal so that the image pickup lens 12 side is upward. The optical member 20 and the 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. When 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 another location. 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 mounted 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 the inner surface 31, and the outer surface of the windshield 30 is referred to as the outer surface 32. The windshield 30 is arranged so as to be inclined inside the vehicle. The windshield 30 is arranged so as to face the optical axis 13 of the camera 10 and is inclined so as to cover the camera 10. With such an arrangement, the camera 10 can photograph the outside of the vehicle through the windshield 30. For example, by mounting the camera 10 above the inner surface 31 of the windshield 30, the camera 10 captures an image of the outside of the vehicle through the windshield 30.

The optical member 20 is arranged 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 is emitted 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, for example, a prism. The optical member 20 includes, for example, glass, crystal, or the like as a material. Further, the optical member 20 may contain the same material as that contained in the windshield 30. Preferably, the optical member 20 may be formed of the same material as the windshield 30. The material of the optical member 20 is not limited to these.

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

The incident surface 21 is arranged at intervals with respect to the inner surface 31 of the windshield 30, for example. The incident surface 21 is, for example, a flat surface. On the inner surface 31 of the windshield 30, the local portion of the optical member 20 facing the incident surface 21 is a substantially flat surface. The incident surface 21 is a surface substantially parallel to the inner surface 31 of the windshield 30. If the camera 10 can take a picture through the incident surface 21, the incident surface 21 may be arranged so as to be inclined to the inner surface 31 of the windshield 30.

The exit surface 22 is inclined with respect to the incident surface 21. The exit 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 within the angle of view 14 of the camera 10. At this time, the optical member 20 is arranged or the optical member 20 is arranged so that the reflectance of the light reflected on the emitting surface 22 and incident on the camera 10 is 10% or less over the entire angle of view 14 of the camera 10. The inclination of the entrance surface 21 and the exit surface 22 is determined. As a result, the reflectance of the light reflected on the emitting surface 22 of the optical member 20 from the rear of the camera 10 or the direction of the dashboard and incident on the camera 10 on the emitting surface 22 becomes 10% or less, thereby minimizing the reflection. Can be limited. Specifically, for example, the optical axis 13 of the camera 10 is orthogonal to the exit surface 22. As a result, the reflectance on the exit surface 22 can be set to 10% or less over the entire angle of view 14 of the camera 10. The method of setting the reflectance to 10% or less is not limited to this.

Further, the light emitted from the exit surface 22 includes the light within the angle of view 14 of the camera 10. Further, the light emitted from the exit surface 22 in the angle of view 14 of the camera 10 is incident on the exit surface 22 from the incident surface 21. When the light in the angle of view 14 of the camera 10 is incident on the exit surface 22 from the incident surface 21, the reflectance on the exit surface 22 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 image can be improved.

A part of the light 42 that is incident on the windshield 30 from the horizontal direction in front of the vehicle, passes through the windshield 30, and is incident on the incident surface 21 of the optical member 20 is along the optical axis 13 of the camera 10 from the exit surface 22. And exits to reach the camera 10. The light 42 that has passed through such an optical path is the center of photography taken by the camera 10.

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

Next, the operation of the in-vehicle photographing 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 on the camera 10 will be described. After that, a method of suppressing reflection will be described in comparison with a comparative example. First, the path of light from the subject to be photographed will be described.

<Light from the subject>
FIG. 2 is a side view illustrating the path of light from the imaging target in the vehicle-mounted imaging device 1 according to the first embodiment. As shown in FIG. 2, the camera 10 arranged inside 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 emitting surface 22 facing the camera 10 is arranged between the windshield 30 and the camera 10.

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

n11 = (sinθ11) / (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 imaging target 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 given by the following equation (2).

n12 = (sinθ12) / (sinψ12) (2)

Here, for example, θ11 = ψ12 and ψ11 = θ12. The light 41 emitted from the inner surface 31 of the windshield 30 into the vehicle is incident on the incident surface 21 of the optical member 20. On the incident surface 21 of the optical member 20, the light 41 from the imaging target 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 given by the following equation (3).

n13 = (sinθ13) / (sinψ13) (3)

Then, the light 41 that has reached the inside of the optical member 20 reaches the exit surface 22 of the optical member 20. On the exit surface 22, the light 41 from the imaging target is incident at an incident angle θ14 and is emitted from the optical member 20 at a refraction angle ψ14. In this case, the refractive index n14 is given by the following equation (4) according to Snell's law.

n14 = (sinθ14) / (sinψ14) (2)

The light 41 emitted from the exit surface 22 of the optical member 20 is incident on the image pickup lens 12 of the camera 10 and is imaged on the image pickup element of the camera 10. Similarly, for the other light in the angle of view 14 of the camera 10, the light from the photographing target enters the image pickup lens 12 of the camera 10 through the windshield 30 and the optical member 20, and is on the image pickup element of the camera 10. Image is formed with. 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 exit 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 to each other and the light in the angle of view 14 of the camera 10 includes the light 43 incident on the outer surface 32 of the windshield 30 at an incident angle of 0 °, the light 43 Proceeds from the outer surface 32 of the windshield 30 to the inside of the windshield 30 at an exit angle of 0 °, and also incidents on the inner surface 31 of the windshield 30 at an incident angle of 0 °. Then, it 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 perpendicular to the exit surface 22 of the optical member 20, the light 42 emitted from the exit surface 22 along the optical axis 13 and reaches the camera 10 is the incident surface 21. It is incident perpendicularly to the exit surface 22. The inclination 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. As a result, the shooting center can be set in the horizontal direction outside the vehicle.

At the interface of the optical member 20, the reflectance can be defined by the ratio of the amount (intensity) of the reflected light flux to the amount (intensity) of the incident light flux. For example, the reflectance on the exit surface 22 when the light having the maximum angle of view within the angle of view 14 of the camera 10 is incident on the exit surface 22 from the reflected object is set to 10% or less. As a result, it is possible to reduce the reflection of light from an unintended direction on the exit surface 22 and suppress the amount of reflected light from the dashboard or the rear of the camera 10. For example, when the material of the optical member 20 is glass, the reflectance can be set to 10% or less by setting the incident angle to 50 ° or less. The reflectance is set to 10% 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. Specifically, for example, the optical axis 13 of the camera 10 is orthogonal to the exit surface 22. As a result, the reflectance on the exit surface 22 can be set to 10% or less over the entire angle of view 14 of the camera 10, including the maximum angle of view. The method of reducing the reflectance to 10% or less is not limited to this.

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

<Light that causes reflection>
Next, as a comparative example, it will be described that the light from the inside of 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 the reflection generated in the camera 10 due to the reflection by the windshield 30 in the vehicle-mounted photographing apparatus 100 according to the comparative example.

As shown in FIG. 3, the in-vehicle photographing apparatus 100 according to the comparative example has a configuration excluding the optical member 20. The camera 10 of the in-vehicle photographing device 100 captures an image of the outside of the vehicle through the windshield 30. Light from an object to be photographed outside the vehicle is incident on the outer surface 32 of the windshield 30. Here, the light 44 is used as the light from the photographing target outside the vehicle and within the angle of view 14 of the camera 10. The light 44 from the imaging target 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 given by the following equation (5).

n21 = (sinθ21) / (sinψ21) (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 imaging target is incident at an incident angle θ22 and enters the vehicle at a refraction angle ψ22. In this case, according to Snell's law, the refractive index n22 is given by the following equation (6).

n22 = (sinθ22) / (sinψ22) (6)

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

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 shooting center.

In the in-vehicle photographing apparatus 100 according to the comparative example, the light from the equipment in the vehicle such as the dashboard is reflected by the windshield 30 and reflected on the camera 10. As shown in FIG. 3, the light 46 from the inside of the vehicle is reflected by the windshield 30 and reflected on the camera 10. Specifically, the light 46 from the inside of 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 inside of the vehicle is incident at an incident angle θ31 and reflected 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 image pickup lens 12 of the camera 10 and is reflected in the camera 10.

The light reflected on the camera 10 is reflected by the light 46 from the inside of the vehicle by the region 33 included in the angle of view 14 of the camera 10 on the inner surface 31 of the windshield 30. In the figure, the region 33 is indicated by a alternate long and short dash line. In the comparative example, since there is nothing between the region 33 and the camera 10 that blocks the reflected light reflected in the region 33, the light 46 is reflected in the region 33 and reflected in the camera 10.

Further, the optical axis 13 of the camera 10 is set to the horizontal direction in order to set the shooting center in the horizontal direction outside the vehicle. Then, at the lower end of the image of the camera 10, since the incident angle from the dashboard or the like to the inner surface 31 of the windshield 30 is large, the reflectance is also large and a large amount of light is reflected. It is conceivable that the light reflected on the camera 10 becomes large when the angle of view of the camera 10 is large, the reflectance of the region 33 is high, or the incident angle in the region 33 is large.

As described above, in the in-vehicle photographing apparatus 100 according to the comparative example, it is possible to suppress the reflection of the light from the inside of the vehicle reflected on the camera 10 by the windshield 30 inclined so as to cover the camera 10. Can not.

<Method of suppressing reflection>
Next, a reflection suppression method using the in-vehicle photographing apparatus 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 vehicle-mounted photographing apparatus 1 according to the first embodiment.

First, as shown in steps S11 and FIG. 1 of FIG. 4, the optical member 20 having the incident surface 21 and the exit surface 22 is such that the incident surface 21 faces the windshield 30 and the exit surface 22 faces the camera 10. It is arranged between the windshield 30 and the camera 10.

Next, as shown in step S12 and FIG. 1 of FIG. 4, the camera 10 captures an image of the outside of the vehicle through the windshield 30 and the optical member 20. With such a configuration, the light 41 to 43 to be photographed 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. The light 41 to 43 in the angle of view 14 of the camera 10 emitted from the inner surface 31 of the windshield 30 reaches the image pickup lens 12 of the camera. As a result, it is possible to shoot the image to be shot.

On the other hand, among the light emitted from the equipment inside the vehicle such as the dashboard inside the vehicle, the light 46 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 is the lower surface 23 of the optical member 20. Incident in. 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, it is blocked by a light-shielding function formed on the lower surface 23.

As described above, in the present embodiment, the optical member 20 is arranged between the windshield 30 and the camera 10. Therefore, the light 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 can be prevented from reaching the camera 10, and the reflection can be suppressed.

In addition, 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 perpendicularly to the exit surface 22 of the optical member 20 so that the shooting center is in the horizontal direction. As a result, the reflectance of the 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 light 46 from the inside of a vehicle such as a dash boat, the inclination of the windshield 30 can be changed so that the axis of symmetry between the dashboard and the camera 10 is not orthogonal 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 optical axis 13 of the camera 10 can be directed upward and the horizontal direction can be the center of photography.

Next, the effect of this embodiment will be described.
In the present embodiment, the optical member 20 is arranged between the windshield 30 and the camera 10. As a result, it is possible to suppress the light 46 from the inside of the vehicle reflected by the windshield 30 from being 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 exit surface 22 of the optical member 20 in order to photograph the outside of the vehicle through the optical member 20 that refracts light. As a result, the reflectance of the light 46 reflected from the inside of the vehicle, which causes reflection, can be reduced, and 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 makes it possible to easily set the shooting center in the horizontal direction.

The reflectance of the light reflected by the emitting surface 22 and incident on the angle of view 14 of the camera 10 to generate reflection is 10% or less on the emitting surface 22. This makes it possible to suppress reflection due to light from the rear of the camera 10 or from the dashboard or the like. Further, by setting the reflectance on 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 quality of the image can be improved. Further, even if the inclination of the windshield 30 changes slightly depending on the vehicle type, the reflectance remains within 10%, so that it can be applied to various vehicles.

(Embodiment 2)
<Attachment of optical members>
Next, the in-vehicle photographing apparatus 2 according to the second embodiment will be described. In the vehicle-mounted photographing apparatus 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 photographing apparatus 2 according to the second embodiment.

As shown in FIG. 5, the vehicle-mounted photographing apparatus 2 has an 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. There is. As a result, it is possible to prevent the reflected light from being incident from between the windshield 30 and the incident surface 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 in a local portion where the incident surface 21 contacts. Therefore, even if the incident surface 21 is flat, they can be brought into contact with each other.

Due to 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 contacts 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 portion may be brought into contact.

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 match the inner surface 31 of the windshield 30 and attached and brought into contact with each other.

The optical member 20 preferably contains the same material as that contained in the windshield 30. Then, it is preferable that the refractive index of the optical member 20 is 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 do not refract at the contacted interface. Therefore, the windshield 30 and the optical member 20 can be integrated to transmit light.

For example, the 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 exit surface 22. Then, it emits light from the exit surface 22 and reaches the image pickup 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 refractions can be reduced and the optical path of light can be simplified. For example, by setting the angle formed by the incident surface 21 and the exit surface 22 to be the same as the refraction angle ψ41, the light 47 from the horizontal direction outside the vehicle can be easily aligned with the optical axis 13 of the camera 10. 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 centered on the photographing.

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

In addition, the number of refractions can be reduced, and the optical path of light can be simplified. In particular, when the optical member 20 contains the same material as the material contained in the windshield 30, it does not refract 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.

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

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

As shown in FIG. 6, the in-vehicle photographing device 3 includes a processing unit 50 that processes data of an image captured by the camera 10. The processing unit 50 processes the distortion of the image data captured by the camera 10 based on the image acquired by the camera 10 taking a picture of 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 reference data of video. As shown in FIG. 7, the reference data of the video is, for example, a photograph of reference lines 51 arranged at equal intervals in the vertical direction and the horizontal direction in advance. When the X marks 52 arranged at equal intervals in the vertical direction and the horizontal direction are photographed in a state where the distortion can be ignored, the intersection of the reference lines 51 and the X mark 52 overlap each other.

FIG. 8 is a diagram illustrating a simulation result of an image taken by the in-vehicle photographing apparatus 3 according to the third embodiment, and shows image data before processing by the processing unit 50. As shown in FIG. 8, when the X marks 52 arranged at equal intervals in the vertical and horizontal directions are photographed by the in-vehicle photographing device 3, if the image is distorted, a part of the X marks 52 The image 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 portion and the lower portion, and the intersection of the X mark 52 and the reference line 51 occurs at the peripheral portion of the image. The gap with is getting bigger. The processing unit 50 of the in-vehicle photographing device 3 processes the distortion of the image data captured by the camera 10 based on the image distortion data obtained in advance by the simulation as shown in FIG. Specifically, the distortion data of FIG. 8 is held as a table, and the distortion of the actually captured image is corrected so as to return to the state of FIG. 7 based on the distortion data.

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

Although the first to third embodiments have been described above, the configuration in which the configurations of the first to third embodiments are combined with each other is also included in the scope of the technical idea described in the present 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 Exit surface 23 Bottom surface 30 Windshield 31 Inner surface 32 Outer surface 33 Region 41, 42, 43, 44, 45, 46, 47 Optical 50 Processing unit 51 Reference line 52 X mark

Claims (9)

A camera that shoots images and
An optical member arranged between a windshield inclined so as to cover the camera and the camera, the optical member having an incident surface facing the windshield and an exit surface facing the camera.
With
The camera is installed so that the optical axis is tilted above the horizontal, and through the windshield and the optical member, the outside of the vehicle is photographed with the horizontal direction as the imaging center .
In-vehicle photography device. The incident surface of the optical member is in contact with the windshield.
The vehicle-mounted photographing device according to claim 1. The optical member contains the same material as that contained in the windshield.
The vehicle-mounted photographing apparatus according to claim 1 or 2. The incident surface is substantially parallel to the vehicle interior surface of the windshield.
The exit surface is orthogonal to the optical axis of the camera.
The vehicle-mounted photographing apparatus according to any one of claims 1 to 3. Further provided with a processing unit for processing the video data,
The processing unit processes the distortion of the data based on the distortion data of the video acquired in advance.
The vehicle-mounted photographing apparatus according to any one of claims 1 to 4. When light within the angle of view of the camera is incident on the exit surface from the incident surface, the reflectance on the exit surface is 10% or less.
The vehicle-mounted photographing apparatus according to any one of claims 1 to 5. The reflectance of the light reflected on the emitting surface and incident on the angle of view of the camera to generate reflection is 10% or less on the emitting surface.
The vehicle-mounted photographing apparatus 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 is emitted from the exit surface along the optical axis of the camera, and the camera. To reach,
The vehicle-mounted photographing apparatus according to any one of claims 1 to 7. This is a reflection suppression method that suppresses the reflection of light from the inside of the vehicle on the windshield that is tilted so as to cover the camera that captures the image.
An optical member having an incident surface and an exit surface is arranged between the windshield and the camera so that the incident surface faces the windshield and the exit surface faces the camera.
Through the windshield and the optical member , the outside of the vehicle centered on the horizontal direction is photographed by the camera installed so that the optical axis is tilted above the horizontal .
Reflection suppression method.

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