JP2019080289A - On-vehicle imaging apparatus - Google Patents

Abstract

To provide an on-vehicle imaging apparatus capable of preferably picking up images around a vehicle using infra-red rays.SOLUTION: The on-vehicle imaging apparatus includes: an infrared light (10) for projecting infrared light toward surroundings of a vehicle (50); an infrared light camera (20) configured to receive the infrared light to pick up images surroundings of the vehicle; a first polarizing filter (15) disposed on the infrared light for polarizing the infrared light projected from the infrared light in a predetermined direction; and a second polarizing filter (25) disposed on the infrared light camera for allowing the infrared light camera to receive the infrared light polarized in the predetermined direction.SELECTED DRAWING: Figure 1

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to the technical field of an on-vehicle imaging device for imaging the periphery of a vehicle.

  In order to detect an object such as a pedestrian or another vehicle existing around a vehicle, a technique is known in which an on-vehicle camera captures an image of the periphery of the vehicle. In such an apparatus, for example, in order to enable imaging of the surroundings of the vehicle even at night, a technique has been proposed in which imaging is performed by projecting infrared light (see, for example, Patent Document 1).

Unexamined-Japanese-Patent No. 2017-039463

  In the technology described in Patent Document 1 described above, the infrared light reflected by the object enters the camera, whereby the object present around the vehicle is imaged. However, when another device (for example, an oncoming vehicle) is also equipped with a device that emits infrared light, the camera mounted on the own vehicle is not only the infrared light emitted by the own vehicle but also the other vehicle The infrared light projected from can also be incident. As described above, when an unintended infrared ray enters the camera, for example, there may be a problem such as overexposure of an image.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an on-vehicle imaging device capable of suitably imaging the surroundings of a vehicle by using infrared rays.

  An on-vehicle imaging device according to an aspect of the present invention includes an infrared light that projects infrared light toward the periphery of a vehicle, and an infrared camera that receives infrared light and captures an image of the periphery of the vehicle A first polarizing filter provided in the infrared light, which polarizes infrared light emitted from the infrared light in a predetermined direction, and provided in the infrared camera, And a second polarization filter for causing the infrared camera to receive infrared light polarized in a direction.

FIG. 1 is a block diagram showing an overall configuration of a vehicle-mounted imaging device according to an embodiment of the present invention. It is a conceptual diagram which shows the polarization direction of the polarizing filter provided in the infrared light and the infrared camera. It is a conceptual diagram which shows an example of the captured image of the infrared light camera at the time of normal driving | running | working. It is a conceptual diagram which shows an example of the captured image of the infrared light camera at the time of passing with an oncoming vehicle. It is a graph which shows the polarization direction of the infrared light which self-vehicles projected, the reflected light of the infrared light which self-vehicles projected, and the infrared light which an oncoming vehicle projects.

  Hereinafter, embodiments of the on-vehicle imaging device will be described with reference to the drawings.

<Device configuration>
First, the overall configuration of the on-vehicle imaging device according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the on-vehicle imaging device according to the present embodiment.

  As shown in FIG. 1, the on-vehicle imaging device according to the present embodiment includes an infrared light 10, an infrared camera 20, a first polarization filter 15, a second polarization filter 25, and a control unit 30. ing. Since the on-vehicle imaging device performs imaging using infrared light (for example, light of a near red wavelength of about 900 nm different from visible light), an object present in front of the vehicle (for example, at night) , Pedestrians, etc.) can be suitably detected.

  The infrared light 10 is a light capable of projecting infrared light. The infrared light 10 projects infrared light forward of the vehicle through the first polarizing filter 15. The infrared light 10 is configured such that the light emission state is controlled by the light control unit 310 of the control unit 30. The infrared light 10 may be capable of adjusting the intensity of infrared light to be emitted.

  The infrared light camera 20 is a camera capable of receiving infrared light and performing imaging. The infrared camera 20 receives the light incident through the second polarizing filter 25. An image captured by the infrared light camera 20 is input to the image processing unit 320 included in the control unit 30, and is appropriately output after performing various processing. The image data output from the image processing unit 320 is output to, for example, a display included in the vehicle and presented to a passenger of the vehicle. Alternatively, it may be used in a system or the like for detecting an obstacle in front of the vehicle.

  Next, the polarization directions of the first polarization filter 15 and the second polarization filter 25 described above will be specifically described with reference to FIG. FIG. 2 is a conceptual view showing polarization directions of infrared light and a polarization filter provided in the infrared camera.

  As shown in FIG. 2, the polarization direction of the first polarizing filter 15 for polarizing the infrared light emitted by the infrared light 10 is inclined 45 degrees upward to the right. For this reason, the infrared light projected from the infrared light 10 through the first polarizing filter 15 is polarized in the 45-degree direction obliquely upward to the right.

  On the other hand, the second polarization filter 25 that polarizes the infrared light received by the infrared camera 20 is inclined 45 degrees, with the polarization direction rising to the right. For this reason, the infrared light received by the infrared camera 20 through the second polarizing filter 25 is limited to the one that is polarized in the 45-degree direction obliquely upward to the right.

  As described above, the first polarization filter 15 and the second polarization filter 25 have the same polarization direction. The technical effects obtained by aligning the polarization directions of the two polarization filters in this manner will be described in detail later.

<Problems when using infrared light>
Next, problems that may occur when imaging using infrared light will be specifically described with reference to FIGS. 3 and 4. FIG. 3 is a conceptual diagram showing an example of a captured image of the infrared light camera during normal traveling. FIG. 4 is a conceptual diagram showing an example of a captured image of the infrared light camera when passing by an oncoming vehicle. Here, it is assumed that the on-vehicle imaging device does not include the first polarization filter 15 and the second polarization filter 25 described above.

  As shown in FIG. 3, it is assumed that a pedestrian 60 exists in front of the host vehicle 50. In this case, the infrared light projected from the infrared light 10 is irradiated to a zone in front of the host vehicle 50 including the pedestrian 60. Infrared light reflected from the pedestrian 60 or the like is received by the infrared light camera 20 of the vehicle 50. As a result, in the on-vehicle imaging device, a captured image as shown in the figure is captured. As described above, if infrared light is used, the presence of the pedestrian 60 can be suitably recognized even at night, for example.

  As shown in FIG. 4, it is assumed that there is an oncoming vehicle 70 that performs imaging in the same manner as in FIG. 3 using infrared light. In this case, the infrared light camera 20 of the host vehicle 50 is the infrared light reflected from the pedestrian 60 or the like (that is, the reflected light resulting from the infrared light projected from the infrared light 10 of the host vehicle 50) Not only) but also infrared light projected from the oncoming vehicle 70 will be received. As a result, in the on-vehicle imaging device, a captured image as shown in the figure is captured. That is, due to the presence of unintended infrared light (that is, the infrared light emitted by the oncoming vehicle 70), an inconvenience such as overexposure occurs in the image, and the presence of the pedestrian 60 is recognized. It will be difficult.

  In the on-vehicle imaging device according to the present embodiment, each of the infrared light 10 and the infrared camera 20 includes the first polarizing filter 15 and the second polarizing filter 25 in order to solve the above-mentioned problems. There is. The specific solution will be described in detail below.

<Technical effect>
The technical effects of the on-vehicle imaging device according to the present embodiment will be specifically described with reference to FIG. FIG. 5 is a chart showing the polarization directions of infrared light projected by the host vehicle, reflected light of infrared light projected by the host vehicle, and infrared light projected by the oncoming vehicle. In the following example, it is assumed that the on-vehicle imaging device according to the present embodiment is also mounted on the oncoming vehicle 70 in the same manner as the host vehicle 50.

  As shown in FIG. 5, the infrared light emitted from the infrared light 10 of the vehicle 50 is polarized by the first polarizing filter 15 in a direction inclined 45 degrees upward to the right. Further, the polarization direction of the projected infrared light does not change even when it is reflected by an object present in front of the host vehicle 50. For this reason, the reflected light of the infrared light which the own vehicle 50 light-projected also becomes what was polarized in the 45 degree direction diagonally upward as well as the infrared light which light-projected.

  On the other hand, although the infrared light projected from the infrared light 10 of the oncoming vehicle 70 is polarized by the first polarizing filter 15, the direction of the vehicle is opposite, so that it is viewed from the own vehicle 50 The polarization direction is completely reversed. Specifically, the infrared light projected from the oncoming vehicle 70 is polarized in a 45 ° upward slanting direction as shown in the figure.

  Here, in particular, the light received by the infrared light camera 20 is limited by the second polarizing filter 25 to the one that is polarized in the 45-degree direction obliquely upward to the right. In other words, infrared light other than 45 degrees with the polarization direction rising to the right is cut. Therefore, the reflected light whose polarization direction is 45 degrees upward with respect to the right is not cut by the second polarizing filter 25 but is received by the infrared camera 20. On the other hand, infrared light of different polarization directions such as light projected from the oncoming vehicle 70 is cut by the second polarizing filter 25 and not received by the infrared camera 20.

  As described above, in the on-vehicle imaging device according to the present embodiment, only the infrared light projected from the infrared light 10 of the vehicle 50 is received by the infrared camera 20. Therefore, it is possible to preferably avoid the problem such as overexposure due to unintended infrared light being received. Therefore, it becomes possible to preferably recognize the presence of the pedestrian 60 or the like present in front of the host vehicle 50.

  In the example described above, since the oncoming vehicle 70 includes the on-vehicle imaging device similar to the vehicle 50 (that is, the polarization direction of infrared light to be emitted is the same), the vehicle 50 emits light. The polarization direction of the infrared light and the infrared light emitted by the oncoming vehicle 70 are reversed (specifically, the direction shifted by 90 degrees), and as a result, the efficiency of the infrared light emitted by the oncoming vehicle 70 is increased. It is possible to cut Therefore, it is preferable that the polarization directions of infrared light emitted from the on-vehicle imaging device be unified.

  However, even if the oncoming vehicle 70 is not equipped with the on-vehicle imaging device similar to the host vehicle 50 (for example, the projected infrared light is not polarized by the polarizing filter), the second polarizing filter 25 Because infrared light other than in the polarization direction is cut, most of the infrared light emitted from the other vehicle 70 is not received by the infrared light camera 20. Therefore, even when the oncoming vehicle 70 does not include the on-vehicle imaging device similar to the host vehicle 50, the above-described effects can be obtained accordingly.

<Supplementary Note>
Various aspects of the invention derived from the embodiments described above are described below.

(Supplementary Note 1)
The vehicle-mounted imaging device according to appendix 1 includes an infrared light which projects infrared light toward the periphery of a vehicle, an infrared camera which receives infrared light and captures an image of the periphery of the vehicle, Provided in the infrared light, and provided in the infrared camera and a first polarizing filter that polarizes the infrared light projected from the infrared light in a predetermined direction, in the predetermined direction And a second polarization filter for causing the infrared camera to receive polarized infrared light.

  According to the on-vehicle imaging device described in the supplementary note 1, the infrared light emitted from the infrared light is polarized in a predetermined direction by the first polarizing filter. On the other hand, the infrared light received by the infrared camera is limited to the one polarized in a predetermined direction by the second polarizing filter. With this configuration, infrared light emitted from the infrared light can be efficiently received by the infrared camera, while infrared light (for example, light emitted from other than the infrared light) Infrared light emitted from other vehicles is hardly received by the infrared camera. Therefore, when infrared light which is not intended to the infrared light camera (that is, infrared light other than the infrared light emitted by the infrared light of the own vehicle) is incident, for example, overexposure etc. in the captured image It is possible to prevent the occurrence of inconveniences.

  The present invention is not limited to the embodiment described above, and can be suitably modified without departing from the scope and spirit of the invention as can be read from the claims and the specification as a whole. Moreover, it is contained in the technical scope of this invention.

10 infrared light 15 first polarizing filter 20 infrared camera 25 second polarizing filter 30 control unit 310 light control unit 320 image processing unit 50 own vehicle 60 pedestrian 70 oncoming vehicle

Claims (1)

Infrared light which projects infrared light towards the surroundings of the vehicle;
An infrared light camera for receiving infrared light and imaging the surroundings of the vehicle;
A first polarizing filter provided in the infrared light, which polarizes infrared light emitted from the infrared light in a predetermined direction;
A second polarization filter provided in the infrared light camera to cause the infrared light camera to receive infrared light polarized in the predetermined direction;
An on-vehicle imaging apparatus comprising:

Images