JP6202364B2 - Stereo camera and moving object - Google Patents

Description

The present invention, the stereo camera polarization direction to obtain a stereoscopic image from the two polarized images obtained from use physician one object imaging equipment to acquire two polarized images an image of the polarization component each receiving mutually orthogonal And a moving body on which the stereo camera is mounted.

  2. Description of the Related Art Conventionally, driver assistance systems such as ACC (Adaptive Cruise Control) having an own vehicle speed adjusting function for measuring an inter-vehicle distance with a preceding vehicle ahead of the own vehicle and maintaining the inter-vehicle distance have been developed. As a technique for measuring the distance to the preceding vehicle, a stereo camera is known that calculates the amount of parallax between parallax images using two parallax images having parallax and measures the distance from the parallax amount to the subject. . As this stereo camera, the one described in Patent Document 1 is known. In the stereo camera of Patent Literature 1, two images obtained through the respective optical members of the left and right lens groups are incident on each polarization filter, thereby obtaining images of two polarization components whose polarization directions are orthogonal to each other. To do. Images of two polarization components from the same subject are respectively incident on polarizer regions arranged corresponding to the arrangement of the light receiving elements in the image sensor of the imaging unit. Each polarizer region is polarized to a light receiving element corresponding to the polarization direction of the incident image. A parallax image is generated from images of two polarization components received by each light receiving element, and the distance to the subject is measured based on the parallax image.

  In the stereo camera disclosed in Patent Document 1, in order to measure the distance to the subject with high accuracy based on the parallax between the left and right images, it is necessary that the corresponding left and right pixels are substantially matched with 0.1 pixel accuracy. For distance measurement, it is indispensable to shoot a chart or the like and calibrate the distortion including the lens individual difference and the positions of the left and right imaging units based on the chart image.

  However, since the stereo camera of Patent Document 1 uses the optical members of the left and right lens groups, the distortion of the left and right optical members differs from each other even if there is a temperature difference between the left and right optical members. As a result, a positional error of several pixels occurs in the corresponding pixels of the image sensor in the left and right imaging units. Further, metal is usually used for the fixture for fixing the position between the left and right imaging units, and the linear expansion coefficient of metal is generally much larger than that of glass. As a result, due to the environmental temperature change, the mounting position relationship between the left and right imaging units easily shifts, and a positional error of several pixels occurs in pixels corresponding to each other in the imaging elements in the left and right imaging units. The left and right images cannot be completely superimposed. As a result, when the distortion of the lens or the like changes due to the temperature, the corresponding pixels on the left and right sides are shifted. Since the error due to such environmental temperature changes is corrected, it is necessary to perform calibration including correction of distortion of the optical member and correction of the mounting positions of the left and right imaging units at any time. there were.

  In the stereo camera of the previous application (Japanese Patent Application No. 2012-214673) filed earlier by the present inventor, the left and right images from the subject are guided to the polarizing filter by the same optical path, and two images of the polarization components orthogonal to each other by the polarizing filter. To be polarized. The two images are superposed on one optical path, and the superposed image is formed on a region dividing filter through an optical member of one lens group. This area division filter is obtained by arranging the polarizer regions in correspondence with the vertical and horizontal arrangements of the light receiving elements in the image sensor. The image is separated into two images having parallax by a region dividing filter, and light is received by adjacent light receiving elements in the image sensor. For this reason, since two images having parallax are formed on the image sensor via the optical member of one lens group, even if the distortion of the optical member changes due to a temperature change, The imaging positions are shifted in the same way. The influence of the distortion of the optical member due to the temperature and the change in the mounting position of the imaging means on the distance measurement calculation for calculating the distance to the subject is small. Therefore, it is not necessary to perform calibration including correction of the distortion of the optical member accompanying the temperature change and correction of the mounting position shift of the imaging means, and the cost of the apparatus itself is suppressed.

  However, the stereo camera of the prior application has a problem in that the corresponding pixel values in the two images having the orthogonal polarization directions do not match each other. In this case, the accuracy in the matching process is lowered, and the ranging accuracy is lowered. Specifically, when the imaging means is mounted on a vehicle and the front of the host vehicle is imaged, what is shown is a vertical or horizontal surface such as a utility pole standing on the road surface or a forward vehicle. When there is a lot of reflected light from the surface in the vertical or horizontal direction, and the polarizer on the image sensor is also in the vertical and horizontal directions, it is greatly affected by the polarization dependence of the subject with many vertical or horizontal surfaces, The light receiving elements in the vertical and horizontal arrangement respectively receive the light and corresponding pixel values in the two images do not match each other.

The present invention has been made in view of the above problems, and the objects thereof are as follows. By suppressing the influence of the polarization difference caused by the reflected light from the vertical and horizontal surfaces of the subject, the luminance of the pixels at the corresponding position can be matched , and the accuracy of the distance measurement calculation can be improved. It is to provide a stereo camera and a moving body equipped with the stereo camera.

  In order to achieve the above object, the invention of claim 1 is directed to a polarization multiplexing unit that superimposes two polarization components having different polarization directions in a direction orthogonal to each other on one optical path, and two polarization components. In an imaging device including an imaging unit having an imaging element in which a plurality of light receiving elements each receiving light is arranged, each polarizer region is arranged with respect to the arrangement of the light receiving elements and each polarization component incident from one optical path A polarization splitting angle of the zone splitting filter, comprising a zone splitting filter that transmits light through each of the polarizer regions corresponding to the polarization component of the light, splits the light into two polarization components, and emits the light to the light receiving element; Is 45 degrees with respect to the arrangement direction of the pixels of the light receiving element.

  In the present invention, the polarization transmission angle of the area division filter is 45 degrees with respect to the arrangement direction of the light receiving elements of the image pickup unit. Therefore, when the stereo camera is used as an in-vehicle camera as described above, it is oblique to the road surface. By superimposing two images using the polarization of the directional plane, the polarization by the vertical and horizontal planes of the subject compared to the conventional case where the polarization transmission angle of the region dividing filter is approximately 0 degrees. Dependency can be reduced. Therefore, it is possible to substantially eliminate the difference in luminance between the two lights received by the light receiving element, and to obtain a unique effect that the luminance of the pixels at the corresponding positions can be substantially matched.

It is a figure which illustrates correspondence of the positional relationship of an optical filter and an image sensor. It is sectional drawing of the positional relationship of an optical filter and an image pick-up element. It is sectional drawing which shows the structure of an imaging part. It is the schematic explaining the operation | movement in an imaging device. It is a figure which shows Example 1 of an imaging device. It is a figure which shows the modification 1 of Example 1 of an imaging device. It is a figure which shows the modification 2 of Example 1 of an imaging device. It is a figure which shows the modification 3 of Example 1 of an imaging device. It is a figure which shows Example 2 of an imaging device. It is a figure which shows the modification 1 of Example 2 of an imaging device. It is a figure which shows the modification 2 of Example 2 of an imaging device. It is a figure which shows the modification 3 of Example 2 of an imaging device. It is a figure which shows Example 1 of the imaging device which concerns on one Embodiment of this invention. It is a figure which shows Example 2 of the imaging device which concerns on this embodiment. It is the schematic which shows the structure of Example 1 of the stereo camera which concerns on one Embodiment of this invention. It is a figure which shows Example 2 of the stereo camera which concerns on this embodiment. It is a figure which shows Example 2 of the stereo camera which concerns on this embodiment. It is the schematic which shows the mobile body carrying a stereo camera. It is a figure which shows the modification 1 of Example 2 of the stereo camera which concerns on this embodiment. It is a figure which shows the modification 2 of Example 2 of the stereo camera of this embodiment. It is a figure which shows Example 3 of the stereo camera of this embodiment. It is the schematic which shows Example 4 of the stereo camera of this embodiment. It is the schematic which shows Example 5 of the stereo camera of this embodiment. It is the schematic which shows the modification of Example 5 of the stereo camera of this embodiment.

The configuration of the embodiment according to the imaging apparatus of the present invention will be described below.
FIG. 1 is a diagram illustrating the correspondence of the positional relationship between the optical filter unit and the imaging unit. FIG. 2 is a cross-sectional view of FIG. As shown in both drawings, the imaging apparatus 1 includes an imaging unit 100 and an optical filter unit 200. The imaging unit 100 includes an imaging element 101 that includes a plurality of light receiving elements, and a substrate 102 that supports the imaging element 101. The image sensor 101 has a plurality of light receiving elements arranged two-dimensionally in the vertical and horizontal directions, and transmits S-polarized component light and P-polarized component light having polarization components in polarization directions orthogonal to each other transmitted through the optical filter unit 200. Light is received by each light receiving element. For example, a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), or the like can be used for the image sensor 101. Here, a monochrome sensor is assumed as the imaging device, but the image sensor is not limited to this. For example, a color sensor (for example, an RCCC (red, clear, clear, clear) array, Bayer (RGB (red, green, blue)) is used. )) Sequence etc.).

  The optical filter unit 200 includes a filter substrate 201, a polarizing filter layer 202, and a filling layer 203. The filter substrate 201 is a transparent substrate that transmits incident light incident on the optical filter unit 200 via an imaging lens (not shown). The filter substrate 201 can be made of a transparent material that can transmit light in a use band (for example, a visible light region and an infrared region). The transparent material is, for example, glass, sapphire or quartz, or quartz glass, Tempax glass, plastic, engineering plastic, or synthetic resin. A polarizing filter layer 202 is formed on the surface of the filter substrate 201 on the image sensor 101 side. A filling layer 203 is further formed so as to cover the polarizing filter layer 202. The filling layer 203 may be formed using an adhesive that has good translucency, glass adhesion, and precision. Of the light incident on the optical filter unit 200, the light transmitted through the polarizing filter layer 202 is incident on the pixel region of the image sensor 101. In the polarizing filter layer 202, a polarizer corresponding to the pixel size of the image sensor 101 is formed by dividing the region. The polarizing filter layer 202 polarizes the incident light into S-polarized component light and P-polarized component light. The S-polarization component transmission region and the P-polarization component transmission region may be strip-shaped patterns. In the region where the polarizing filter layer 202 is formed, images of the P-polarized component and S-polarized component regions are taken, and these are used for various information detection as a parallax image by forming a differential image as will be described later. .

  FIG. 3 is a cross-sectional view illustrating the configuration of the imaging unit. The imaging unit 100 shown in the figure includes an imaging element 101, a birefringent plate 103, and a region dividing filter 104 on a substrate (not shown). The birefringent plate 103 branches (branches) incident light into polarized light components having polarization directions orthogonal to each other, for example, S-polarized light components and P-polarized light components, with respect to X1, which is the deflection direction of the birefringent plate. . The region dividing filter 104 includes a first polarizer region that transmits only light of a polarization component in one direction among polarization directions orthogonal to each other, and a second polarizer region that transmits only light of a polarization component in the other direction. It is divided into and. For the birefringent plate 103, for example, a member such as quartz or calcite can be used. In the birefringent plate 103, the shift amount, which is the refraction direction and the branching distance, can be the refraction direction and the shift amount corresponding to the region division of the region division filter 104. The refraction direction and the shift amount of the birefringent plate 103 can be adjusted by appropriately changing the crystal axis and the thickness thereof. The region dividing filter 104 selectively transmits incident light, for example, an S polarizer region 104s that transmits only S-polarized component light and a P polarizer region 104p that transmits only P-polarized component light. It is divided.

  In the imaging unit 100 having such a configuration, incident light from the same position is branched into S-polarized component light and P-polarized component by the birefringent plate 103. Next, the S-polarized component light transmitted through the S-polarizer region 104s and the P-polarized component light transmitted through the P-polarizer region 104p are received by the corresponding polarizer regions of the image sensor. Thus, by calculating the luminance ratio between pixels corresponding to incident light from the same position, an accurate polarization ratio can be obtained not only at a flat portion of the subject but also at an edge portion or the like.

  FIG. 4 is a schematic diagram for explaining the operation of the imaging unit. As can be seen from the figure, S-polarized component pixels are extracted from the entire input image in units of pixels to form an S image in the output image. On the other hand, P-polarized component pixels are extracted from the entire input image to form a P image in the output image.

  FIG. 5 is a diagram illustrating the first embodiment of the imaging apparatus. The region dividing filter 104 shown in the figure is configured by arranging a plurality of S polarizer regions 104s and a plurality of P polarizer regions 104p corresponding to the lattice pattern of a plurality of light receiving elements (see FIG. 1). The area division filter 104 is formed of a plurality of polarizers corresponding to the pixel size of the image sensor 101 (the size of the light receiving element, pixels). In the area division filter 104, a plurality of S polarizer regions 104s and a plurality of P polarizer regions 104p are alternately arranged in a direction orthogonal to the optical axis. That is, the S polarizer region 104s and the P polarizer region 104p are arranged in a horizontal stripe pattern.

  As shown in FIGS. 5A and 5B, when the incident light L from the same position is incident on the birefringent plate 103, the birefringent plate with respect to X1 which is the deflection direction of the birefringent plate. In 103, the S-polarized component light is transmitted as it is, and the P-polarized component light is refracted and transmitted in the refraction direction R which is the deflection direction. Using the S-polarizer region 104s and the P-polarizer region 104p of the region dividing filter 104, only the light of the S-polarized component or the light of the P-polarized component is selected and incident for each light receiving element of the image sensor. And as shown in FIG.5 (c), incident light in the area | region enclosed with a broken line in the figure for every light receiving element 101s and 101p of the image pick-up element 101, or the light of the S polarization component of the light L which injected from the same position, or It can be received only as light of the P-polarized component. Specifically, the light of the S-polarized component and the light of the P-polarized component of the light L incident from the same position are received by the light receiving elements having the coordinates at the arrowhead and the coordinates at the arrowhead in the refraction direction R in FIG. It can receive light. As a result, as described above, the imaging apparatus can obtain the polarization ratio and the like by calculating the luminance ratio of the light received by the light receiving element of the arrow origin coordinate and the arrow destination coordinate in the refraction direction R. .

  FIG. 6 is a diagram illustrating a first modification of the first embodiment of the imaging apparatus. The example in which the S polarizer region 104s and the P polarizer region 104p of the region dividing filter 104 shown in the same figure are arranged in a vertical stripe pattern is the same as the examples of FIGS. 5A, 5B, and 5C. Therefore, the description is omitted.

  FIG. 7 is a diagram illustrating a second modification of the first embodiment of the imaging apparatus. The area dividing filter 104 shown in the figure is configured by alternately arranging a plurality of S polarizer regions 104s and a plurality of P polarizer regions 104p corresponding to the lattice pattern of a plurality of light receiving elements (see FIG. 1). Yes. In the region dividing filter 104, a plurality of S polarizer regions 104s and a plurality of P polarizer regions 104p are alternately arranged in a direction orthogonal to the optical axis. That is, the S polarizer region 104s and the P polarizer region 104p are arranged in a checkered pattern.

  As shown in FIGS. 7A and 7B, first, when incident light L from the same position is incident on the birefringent plate 103, the birefringent plate with respect to X1 which is the deflection direction of the birefringent plate. The light of S polarization component is transmitted as it is through 103, and the light of P polarization component is refracted in the refraction direction R which is the deflection direction and transmitted. Using the S-polarizer region 104s and the P-polarizer region 104p of the region dividing filter 104, only the light of the S-polarized component or the light of the P-polarized component is selected and incident for each light receiving element of the image sensor. Then, as shown in FIG. 7C, for each of the light receiving elements 101 s and 101 p of the image sensor 101, the incident light in the region surrounded by the broken line in FIG. It can be received only as light of the P-polarized component. Specifically, the light of the S-polarization component and the P-polarization component of the light L incident from the same position are received by the light receiving elements having the coordinates of the arrowhead and the arrowhead in the refraction direction R in FIG. It can receive light.

  FIG. 8 is a diagram illustrating a third modification of the first embodiment of the imaging apparatus. An example in which the S polarizer region 104s and the P polarizer region 104p of the region dividing filter 104 shown in the figure are arranged in a checkered pattern is basically the same as the example of FIGS. 7A, 7B, and 7C. Explanation is omitted for the same reason.

  Next, a second embodiment of the image pickup apparatus using a color sensor as the image pickup element will be described. In this embodiment, an example of an RCCC (red / clear / clear / clear) arrangement will be described as a color sensor. Note that the color sensor that can be used for the image sensor is not limited to the RCCC array. That is, the color sensor may have an RGB (red / green / blue) arrangement, an RGBG (red / green / blue / green) arrangement, and an arrangement corresponding to a plurality of other colors. The clear pixel (clear light receiving element) is used for acquiring imaging data of a pixel to which no color filter is added in response to a decrease in sensitivity due to the color filter. Further, the RCCC array is obtained by adding only red pixels to a monochrome sensor in order to distinguish red of the tail lamp of a preceding vehicle when the imaging apparatus of the present embodiment is used for an in-vehicle camera, for example.

  FIG. 9 is a diagram illustrating a second embodiment of the imaging apparatus. In the region dividing filter 104 shown in the figure, the S polarizer region 104s and the P polarizer region 104p are arranged in a patch shape corresponding to the arrangement of the color sensors. Specifically, as shown in FIG. 9B, the area dividing filter 104 in this embodiment has a P polarizer area 104p (P / R in the figure) arranged in the R array of the color sensor. The area dividing filter 104 arranges the P polarizer region 104p (P / C in the figure) in two C arrays of the color sensor, and the S polarizer region 104s (S / C in the figure) in one C array. It is arranged.

  As shown in FIGS. 9A and 9B, when the incident light L from the same position is incident on the birefringent plate 103, the birefringent plate with respect to X1, which is the deflection direction of the birefringent plate. The light of S polarization component is transmitted as it is through 103, and the light of P polarization component is refracted in the refraction direction R which is the deflection direction and transmitted. Using the S-polarizer region 104s and the P-polarizer region 104p of the region dividing filter 104, only the light of the S-polarized component or the light of the P-polarized component is selected and incident for each light receiving element of the image sensor. Accordingly, as shown in FIG. 9C, only the light of the S-polarized component or the light of the P-polarized component of the light L incident from the same position is received for each of the light receiving elements 101s and 101p of the image sensor 101. Can do.

  First, when the incident light L from the same position is incident on the birefringent plate 103, the light of the S polarization component is transmitted as it is through the birefringent plate 103 with respect to X1, which is the deflection direction of the birefringent plate, and the P polarized light. The component light is refracted and transmitted in the refraction direction R which is the deflection direction. Using the S-polarizer region 104s and the P-polarizer region 104p of the region dividing filter 104, only the light of the S-polarized component or the light of the P-polarized component is selected and incident for each light receiving element of the image sensor. Accordingly, as shown in FIG. 9C, only the light of the S-polarized component or the light of the P-polarized component of the light L incident from the same position is received for each of the light receiving elements 101s and 101p of the image sensor 101. Can do. More specifically, the light of the S-polarization component and the P-polarization component of the light L incident from the same position are received by the light receiving elements at the coordinates of the arrows in the refraction direction R in FIG. It can receive light.

  FIG. 10 is a diagram illustrating a first modification of the second embodiment of the imaging device. The example of the region dividing filter 104 shown in the figure is basically the same as the example of FIGS. 9A, 9B, and 9C except for the direction of deflection of the birefringent plate 103, and the description thereof is omitted. .

  FIG. 11 is a diagram illustrating a second modification of the second embodiment of the imaging device. The imaging unit 100 according to this modification includes birefringent plates 105 and 106 as optical low-pass filters on the incident side of the birefringent plate 103. The birefringent plates 105 and 106 are used to remove the aliasing noise of the image. As shown in FIG. 11A, first, when the incident light L is incident on the birefringent plates 105 and 106 from the same position, the birefringent plates 105 and 106 cause the light L incident from the same position to be incident on the respective birefringent plates 105 and 106. The light is branched twice according to the deflection directions X2 and X3 of the refracting plate. In other words, the birefringent plate 105 branches the light L incident in the polarization direction X2 (the refraction direction Ra in FIG. 11B) corresponding to the birefringence axis shifted by 45 degrees into a double image. Next, the birefringent plate 106 further branches into a double image in the polarization direction X3 (refractive direction Rb in FIG. 11B) corresponding to the birefringence axis of 135 degrees. Thereby, the incident light L is branched into four points to realize an optical low-pass filter. Then, using the birefringent plate 103, the S-polarized component light is transmitted as it is, and the P-polarized component light is refracted and transmitted in the polarization direction X1 (refractive direction R in FIG. 11B). Using the S-polarizer region 104s and the P-polarizer region 104p of the region dividing filter 104, only the light of the S-polarized component or the light of the P-polarized component is selected and incident for each light receiving element of the image sensor. As a result, as shown in FIG. 11C, only the light of the S-polarized component or the light of the P-polarized component of the light L incident from the same position is received for each of the light receiving elements 101s and 101p of the image sensor 101. be able to.

  FIG. 12 is a diagram illustrating a third modification of the second embodiment of the imaging device. The example of the region division filter 104 shown in the figure is basically the same as the example of FIGS. 11A, 11B, and 11C except for the deflection direction of the birefringent plate 103, and the description thereof is omitted. .

FIG. 13 is a diagram illustrating Example 1 of the imaging device according to the embodiment of the present invention. The imaging unit 100 of the present embodiment uses an RGB (red, green, blue) array (Bayer array) as a color sensor. Further, the imaging unit 100 of the present embodiment uses the birefringent plate 103 to polarize light in a direction of 45 degrees with respect to the arrangement of the light receiving elements of the imaging element. In the imaging unit 100 according to the present exemplary embodiment, the S-polarizer region 104s and the P-polarizer region 104p of the region dividing filter are arranged in a patch shape corresponding to the arrangement of the color sensors. As shown in FIG. 13A, the imaging unit 100 of the present embodiment includes birefringent plates 105 and 106 as optical low-pass filters on the incident side of the birefringent plate 103. As shown in FIG. 13B, the region dividing filter 104 has a P polarizer region 104p (P (C) / R in the figure) arranged in an R array of the image sensor 101 as a color sensor. The area dividing filter 104 arranges P polarizer regions 104p (P (C) / C in the figure) in two C arrays of the image sensor 101 as a color sensor, and S polarizer regions 104s (in one C array). S (C) / C) in the figure is arranged.

  As shown in FIG. 13A, in the imaging unit 100 of this embodiment, first, when the incident light L is incident on the birefringent plates 105 and 106 from the same position, the light L incident from the same position is The birefringent plates 105 and 106 are branched twice according to the deflection directions X2 and X3 of the birefringent plates. That is, the birefringent plate 105 branches the light L incident in the polarization direction X2 (the refraction direction Ra in FIG. 13B) corresponding to the birefringence axis into a double image. Next, the birefringent plate 106 further branches into a double image in the polarization direction X3 (the refraction direction Rb in FIG. 13B) corresponding to the birefringence axis. Thereby, the incident light L is branched into four points to realize an optical low-pass filter. Then, using the birefringent plate 103, the light of the S-polarized component is transmitted as it is, and the light of the P-polarized component is refracted and transmitted in the polarization direction (the refraction direction R. The S-polarizer region 104s of the region dividing filter 104 and Using the P polarizer region 104p, only S-polarized component light or P-polarized component light is selected and incident on each light-receiving element of the image sensor, whereby the refraction direction R in FIG. As shown in (), each of the light receiving elements 101s and 101p of the image sensor 101 can receive only the light of the S-polarized component or the light of the P-polarized component of the light L incident from the same position.

  As described above, when the polarization direction X1 of the birefringent plate 103 is set to a direction of 45 degrees with respect to the arrangement of the light receiving elements of the image sensor, they are adjacent to each other as shown in the refraction direction R of FIG. Light can be dispersed into four pixels, and an ideal optical low-pass filter can be realized. Further, the imaging apparatus of the present embodiment is a light receiving element (pixel) having the coordinates of the arrow in the refraction direction Ra and the coordinates of the arrow in the refraction direction Ra in FIG. The light of the S polarization component and the light of the P polarization component can be received. Therefore, the imaging apparatus can obtain the polarization ratio and the like by calculating the luminance ratio of the light received by the light receiving element having the coordinates of the arrow in the refraction direction Ra and the coordinates of the arrow in the direction of refraction R.

  FIG. 14 is a diagram illustrating Example 2 of the imaging device according to the present embodiment. An imaging apparatus using a color sensor as an imaging element will be described with reference to FIG. In this embodiment, an example of an RGB (red / green / blue) array (Bayer array) will be described as a color sensor. Further, the imaging unit 100 of the present embodiment uses the birefringent plate 103 to polarize light in a direction of 45 degrees with respect to the arrangement of the light receiving elements of the imaging element. As shown in FIG. 14B, in the imaging apparatus of the present embodiment, the S-polarizer region 104s and the P-polarizer region 104p of the area dividing filter are arranged in a patch shape corresponding to the arrangement of the color sensors. As shown in FIG. 14A, the imaging apparatus of the present embodiment includes birefringent plates 105 and 106 as optical low-pass filters on the incident side of the birefringent plate 103. The area dividing filter 104 has a P polarizer area 104p (P (C) / R in the figure) arranged in an R array of the color sensor. The area dividing filter 104 arranges a P polarizer region 104p (P (C) / G in the figure) and an S polarizer region 104s (S (C) / G in the figure) in two G arrays of the color sensor. ing. In the area dividing filter 104, the P polarizer area 104p (P (C) / B in the figure) is arranged in the B array of the color sensor.

  As shown in FIG. 14A, in the imaging apparatus of the present embodiment, first, when incident light L is incident on the birefringent plates 105 and 106 from the same position, the light L incident from the same position is birefringent. The plates 105 and 106 are branched twice according to the deflection directions X2 and X3 of the birefringent plates. That is, the birefringent plate 105 branches the light L incident in the polarization direction X2 (the refraction direction Ra in FIG. 14B) corresponding to the birefringence axis into a double image. Next, the birefringent plate 106 further branches into a double image in the polarization direction X3 (the refraction direction Rb in FIG. 14B) corresponding to the birefringence axis. As a result, as shown in FIG. 14C, only the light of the S-polarized component or the light of the P-polarized component of the light L incident from the same position is received for each of the light receiving elements 101s and 101p of the imaging device 101. be able to.

  As described above, in the imaging apparatus of this embodiment, the polarization direction of the birefringent plate is set to a direction of 45 degrees with respect to the arrangement of the light receiving elements of the imaging element. As a result, as shown in the refraction direction R in FIG. 14B, light can be dispersed to four adjacent pixels, and an ideal optical low-pass filter can be realized. Further, the imaging device is a light receiving element (pixel) having the coordinates of the arrow in the refraction direction Ra and the coordinates of the arrow in the refraction direction R in FIG. 14B, and the S polarization component of the light incident from the same optical path. The light and the light of the P-polarized component can be received. Therefore, the imaging apparatus can obtain the polarization ratio and the like by calculating the luminance ratio of the light received by the light receiving element having the coordinates of the arrow in the refraction direction Ra and the coordinates of the arrow in the direction of refraction R.

The configuration of the embodiment according to the stereo camera of the present invention will be described below.
FIG. 15 is a schematic diagram illustrating a configuration of the stereo camera according to the first embodiment of the present invention. A stereo camera 300 shown in FIGS. 15A and 15B includes a polarization superimposing module 301, a lens 302, a filter 303, and an image sensor 304. The polarization superimposing module 301 includes a polarizing beam splitter 301-1, a polarizing filter 301-2, and a mirror 301-3. A stereo camera 300 shown in FIG. 15 combines two optical paths having parallax using a polarizing beam splitter 301-1 and a polarizing filter 301-2, and captures an image with one imaging element 304 via one lens 302. That is, the two optical paths are completely combined in front of the lens 302 and only one lens passes. For this reason, even if the lens characteristics shift with temperature, the lens position shifts, or the sensor position shifts, both the images are shifted in the same way, so the influence can be completely canceled. As a result, it is possible to realize a stereo camera with extremely high environmental resistance. In addition, it is inexpensive because only one lens and sensor are required. Further, even when the positional relationship between the image sensor and the lens is deviated, since the left and right images are similarly deviated, the influence can be canceled in principle. A filter 303 in FIG. 15 is a filter having a polarizer for each pixel. However, in the configuration of FIG. 15, there is an optical path length difference between the left and right optical paths. For example, a process for compensating for the optical path length difference generated by the pixel matching process in the parallax between two images is necessary. Absent.

  16 and 17 are diagrams showing a configuration of the stereo camera according to the second embodiment of the present embodiment. As shown in FIG. 17, in the stereo camera 400, an image sensor 402 is mounted on a substrate 401, and an optical filter 403 is disposed in close contact with the image sensor 402. Subject information is photographed through the imaging lens 404. In front of the imaging lens 404, a polarization selection type cross prism 405 that constitutes a polarization multiplexing unit is disposed. Further, triangular prisms 408 and 409 are provided in the vicinity of the side surfaces 406 and 407 of the polarization selective cross prism 405.

  The stereo camera 400 has a region-dividing polarization filter that can extract P-polarization information and S-polarization information in units of pixels as the optical filter 403. In addition, a polarization-selective cross prism 405 is disposed in front of the imaging lens 404, and two prisms 408 and 409 are disposed adjacent to the cross prism 405. The prisms 408 and 409 have total reflection surfaces that reflect and reflect light from the + Z direction in the Y-axis direction. The polarization-selective cross prism 405 polarization-reflects the S-polarized component light incident on the side surface 406 from the −Y direction and the P-polarized component light incident on the side surface 407 from the + Y direction in the direction of the side surface 410. As a result, it is possible to extract an S-polarized image in the −Y direction and a P-polarized image in the + Y direction.

  Unlike the stereo camera 300 of FIG. 15, the stereo camera 400 of FIGS. 16 and 17 can simultaneously capture a P-polarized image and an S-polarized image in the + Z direction. Further, as apparent from FIG. 17, since there is a certain distance between the effective ray ranges of the left and right prisms 408 and 409, a parallax image can be formed from the P-polarized image and the S-polarized image. As described above, the stereo camera of the present embodiment is configured as a stereo camera capable of photographing distance information to the subject. Compared to a conventional stereo camera in which a single image sensor and two single lenses are arranged in parallel, the cost can be reduced because only one image lens and image sensor are required. Further, in the conventional stereo image pickup apparatus, a distance measurement error due to a change in the baseline length due to thermal expansion of a housing supporting between the lenses occurs. However, in this imaging apparatus, there is only one imaging lens, and the prism itself corresponding to the support member itself has a small coefficient of thermal expansion relative to metal, so it is possible to suppress the influence of the change in baseline length on distance measurement. It is.

  The stereo camera according to the present embodiment can be used, for example, for confirming the front of a vehicle 500 as a moving body as shown in FIG. The vehicle front confirmation device includes a stereo camera 501 installed near the rearview mirror inside the windshield of the automobile 500, and a signal processing device for warning the driver and controlling the vehicle based on information from the stereo camera 501. 502. As a warning method to the driver, the obstacle information is warned by voice or the like using a speaker. As vehicle control, if there is an obstacle, the vehicle is decelerated. If the stereo camera of this embodiment is used, it is possible to acquire not only image information in front of the vehicle but also distance information to the preceding vehicle or pedestrian in front of the vehicle, and if there is an obstacle, an early warning is given to the driver. Thus, driving safety can be ensured.

  In addition, the stereo camera of the present embodiment combines a television that displays a three-dimensional image to a human and a display device such as a movie projector by projecting different images to the left and right eyes. As a result, a three-dimensional image acquisition / display system that acquires and displays a three-dimensional image can be configured. The human eye is sensitive to left and right image rotation, size, vertical shift, and differences in image quality. For this reason, a conventional stereo camera having two lenses requires a complicated operation technique so that the left and right lenses are interlocked to change the optical axis, image size, and focus when changing the zoom / focus. It was said. On the other hand, in the configuration of the present invention, since an image having two parallaxes is incident on a single eye, if the zoom and focus of a single lens are changed, the same change is reflected in the binocular image. Is done. As a result, it is possible to obtain a natural stereoscopic image that can suppress the optical axis, the image size, and the focus shift caused by having two different optical characteristics for the right eye and the left eye. Note that when the optical system such as zoom is made variable, it is very difficult to strictly correct the characteristics of the two lenses, so the configuration of the present invention is particularly useful.

  Further, since the phenomenon that the angle of incident light becomes shallow due to the refractive index of the prism becomes unusable, the optical layout becomes slightly larger, but the prisms 408 and 409 in the configuration of FIG. 17 are replaced with mirrors 411 and 412 as shown in FIG. The configuration of the embodiment may be used. Further, as shown in FIG. 20, the center cross prism is not a prism shape but a combination of simple cross-shaped polarizing plates 450-1 and 450-2 (in FIG. 20, a polarization selective cross plate 450). good. In that case, the phenomenon that the angle of incident light becomes shallow due to the refractive index of the prism becomes unusable, and the optical layout becomes slightly larger, but less glass material is used, so the cost can be reduced. The left and right prisms may be configured, and the central portion may be a polarization selective cross plate.

Next, a stereo camera according to a third embodiment will be described.
FIG. 21 is a schematic diagram illustrating a third embodiment of the stereo camera. The stereo camera 400 shown in FIG. 21 is provided with sensor units above and below the polarization-selective cross prism 405. For example, the image sensor 414 is color, and the image sensor 402 is monochrome. Alternatively, the imaging element 414 is a high resolution monochrome, and the imaging element 402 is a low resolution color. In general, assuming that color information does not require higher spatial resolution than luminance information and distance information, high-sensitivity, high-resolution monochrome sensors that can ensure high ranging performance, and color sensors that are less sensitive than monochrome Use in a set called low resolution. As a result, high ranging performance and color information can be obtained simultaneously from a bright scene to a dark scene. Also in this case, calibration is easy because the optical axes coincide on the left and right.

Next, a fourth embodiment of the stereo camera will be described.
FIG. 22 is a schematic diagram illustrating the configuration of a stereo camera according to the fourth embodiment. A stereo camera 400 shown in FIG. 22 has a raindrop detection function. The LED infrared light source 420 is projected onto the windshield 421, and the raindrops adhering to the windshield 421 are observed by viewing the reflected light through the optical filter 423 that passes only the light of the projection wavelength added to the upper surface of the sensor. It is possible to detect. And since the whole surface of a windshield can be utilized as a detection area, raindrop detection with higher sensitivity is attained. Raindrops adhering to the windshield 421 by projecting the LED infrared light from the light source 420 onto the windshield 421 and seeing the reflected light through the optical filter 423 that passes only the light of the projection wavelength added to the upper surface of the sensor. Can be detected. In order to improve the accuracy, it is important that the detection area is large, but by using the upper part of FIG. 22, it is possible to detect the entire screen without interfering with the stereo camera. In addition, as the detection, it is only necessary to see the sum of the amount of reflected light on the entire screen, so that it is not always necessary to use an imaging device for detection, and the resolution of the lens for raindrop detection is not necessary. For this reason, there is no problem even in a configuration using one PD 422 and a simple lens (for example, a single lens) 424.

Here, fixing of the stereo camera will be described.
The cross prism 405 and the prisms 408 and 409 may be fixed with an adhesive. When it is necessary to adjust the angle of the prism in order to match the rays of the left and right images, there may be a slight gap between the cross prism 405 and the prisms 408 and 409. In that case, the cross prism 405 and the prisms 408 and 409 are preferably fixed with a holding member (not shown) that holds the gap. When the holding member is a metal, the metal has a very large coefficient of thermal expansion as compared with the glass mainly constituting the prisms 408 and 409. Therefore, it is preferable that the metal holding member is as small as possible so as to fill the gap so that the metal holding member can be as short as possible. Further, if possible, if the holding member is made of glass having a low coefficient of thermal expansion, the environmental resistance to temperature characteristics is improved.

Next, a fifth embodiment of the stereo camera will be described.
FIG. 23 is a schematic diagram showing a fifth embodiment of the stereo camera. This embodiment uses a PBS (polarization beam splitter) film and a mirror surface (reflection surface) without using the polarization-selective cross prism or the polarization-selective polarizing plate used in the first and second embodiments. Yes. And it is the structure which can solve the subject that the optical path length difference has arisen in the right and left optical path in Example 1. FIG. In the configuration of the present embodiment, the left and right optical path lengths are substantially the same. For this reason, as with a normal stereo camera, parallax can be obtained simply by searching only the pixels in the horizontal direction at the time of parallax calculation. Further, in this configuration, unlike the case of using a cross prism, since one PBS film and a mirror are used, there is no defect (gap) at the center of the screen, and processing for filling the gap described later is not necessary. One light R is reflected by the mirror surface (reflection surface) 433, and P-polarized light of the light R is reflected by the PBS film 431. The other light L is reflected by the mirror surfaces 432 and 434, and the S-polarized light of the light L passes through the PBS film 431. Then, P-polarized light and S-polarized light are combined and incident on the imaging lens 404 to form an image on the imaging element 402. The lights L and R have the same optical path length difference. Here, the PBS film 431 may be a multilayer film or a wire grid polarizer, but a wire grid polarizer having stable performance with respect to a wide range of incident angles and wavelengths. It is desirable to use

  Further, in order to make the optical system small in the fifth embodiment, the angle α formed by the PBS film and the mirror surface with the light beam at the center of the angle of view is set to be larger than 45 degrees. FIG. 23A shows a case where the angle α formed by the mirror surface on which the light reflected or transmitted by the PBS film enters is set to 52 degrees. FIG. 23B shows a case where α is set to 45 degrees. In the case where α in FIG. 23B is 45 degrees, the light beam at the angle of view of the imaging lens 404 is larger in the left-right direction in the figure than in the case where α is 52 degrees in FIG. Jumping out. In order to cover the light beam that has jumped out, the size of the prism is increased. That is, the prism size can be reduced by setting the angle formed by the PBS film and the mirror surface to the light beam at the center of the angle of view to be larger than 45 degrees. The upper limit value of α is 90 degrees. However, when the upper limit value of α is 90 degrees, the prism size is larger than when the angle is 45 degrees, and the optimum value depends on the angle of view of the lens. Furthermore, as shown in FIG. 23A, the optical diaphragm 435 is arranged closer to the prism side, whereas the optical diaphragm 435 is arranged inside the imaging lens 404 as shown in FIG. In the arrangement of the optical aperture 435 in FIG. 23, the light beam already has a spread according to the angle of view with respect to the prism, and the size of the prism is larger than that of the prism in the case of the arrangement of the optical aperture 435 in FIG. It is getting bigger. The position of the optical aperture of the imaging lens is preferably the position of the front aperture located in front of the imaging lens closer to the prism side.

  As shown in FIG. 24C, the area dividing filter in the imaging apparatus of the present embodiment has a polarization transmission angle of 45 degrees with respect to the horizontal and vertical pixel arrangement. In this case, in such a configuration in which the left and right images are combined using the superimposing element, the axial direction of the polarization multiplexing element that combines the left and right images such as the PBS film 431 used for multiplexing is also captured. It is necessary to turn 45 degrees from the pixel arrangement of the element. In a stereo camera, the values of the corresponding pixels on the left and right need to match, but if the polarizer is arranged in the horizontal and vertical directions with respect to the pixel array, the incident light has a polarization ratio of S-polarized light and P-polarized light. If it is not 1, the pixel value at the corresponding position is shifted due to the influence of the polarization ratio. This shift lowers the accuracy in the stereo matching process and causes a decrease in distance measurement accuracy. Therefore, it is desirable that the polarization ratio of light from the subject is small. As a factor for the generation of the polarization ratio, a vertical plane and a horizontal plane with respect to the camera are generated largely as can be seen from the Fresnel reflection formula. On the other hand, there is little impact on things standing diagonally. In an actual environment, especially when an in-vehicle camera is taken into consideration, what is shown is basically a vertical or horizontal surface such as a utility pole standing on the road surface or a vehicle ahead. Therefore, the polarization ratio is small in the oblique direction with respect to the road surface. Basically, stereo cameras are installed parallel to the road surface. Therefore, as in the configuration of the present embodiment, providing the region division filter with a polarization transmission angle in the direction of 45 degrees with respect to the horizontal and vertical pixel arrangement eliminates differences other than the parallax between the left and right images. The present invention is also very effective in improving the ranging accuracy of the stereo camera.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect 1)
Each polarizer region is arranged with respect to the arrangement of the light receiving elements, and light of each polarization component incident from one optical path is transmitted through each polarizer region corresponding to the polarization component of the light, and light of two polarization components. The region dividing filter 104 is branched into the light receiving element and emitted to the light receiving element. The region dividing filter 104 has a polarization transmission angle of 45 degrees with respect to the arrangement direction of the pixels of the light receiving element. According to this, as described in the above embodiment, the polarization transmission angle of the region dividing filter is 45 degrees with respect to the arrangement direction of the light receiving elements of the imaging unit. As described above, when a stereo camera is used as an in-vehicle camera, two images are superimposed using polarized light in a plane oblique to the road surface. As a result, the polarization dependency due to the vertical and horizontal planes of the subject can be reduced as compared with the conventional case where the polarization transmission angle of the region division filter is approximately 0 degrees. Therefore, the difference in luminance between the two lights received by the light receiving element can be substantially eliminated, and the luminance of the pixels at the corresponding positions can be substantially matched.
(Aspect 2)
In (Aspect 1), a birefringent plate that branches into light of two polarization components incident from one optical path is provided on the incident side of the region dividing filter, and the refraction direction of the birefringent plate is the polarization transmission direction of the region dividing filter. Determine according to According to this, as described in the above embodiment, the birefringent plate branches light incident from the same optical path. Therefore, the incident light can be branched into two polarized light components orthogonal to each other.
(Aspect 3)
In (Aspect 2 ), an optical low-pass filter is provided in front of the birefringent plate. According to this, as described in the above embodiment, the light incident from the same optical path is branched a plurality of times. Thereby, it is separable into a double image.
(Aspect 4)
In (Aspect 3), the optical low-pass filter includes a birefringent plate and a birefringent plate having a refraction direction of 45 degrees with respect to the refraction direction of the birefringent plate and different from the birefringent plate. Composed. According to this, as described in the above embodiment, the light incident from the same optical path is branched four times. Thereby, it can isolate | separate into a double image by each birefringent plate, respectively. Therefore, the incident light can be branched into four points.
(Aspect 5)
In any one of (Aspect 2 ) to (Aspect 4), the material of the birefringent plate is quartz. According to this, as described in the above embodiment, the refraction direction and the shift amount can be easily adjusted by appropriately changing the thickness and the crystal axis.
(Aspect 6)
In (Aspect 2 ), the birefringent plate is a combination of two birefringent layers whose refraction directions differ from each other by 90 degrees. According to this, as described in the above embodiment, the incident position can be shifted by one pixel in the vertical direction and the horizontal direction by two birefringent plates having different 90-degree axes. For this reason, the pixels acquire the same light position, and the polarization ratio can be obtained by calculating the luminance ratio between the pixels.
(Aspect 7)
In (Aspect 1), a polarization filter that transmits and emits light of two polarization components having different polarization directions in directions orthogonal to each other with respect to the light receiving element corresponding to green is provided. According to this, as described in the above embodiment,
(Aspect 8)
Polarization combining means for superimposing two optical paths of two images having parallaxes having different polarization directions in directions orthogonal to each other, and receiving light of polarization components of at least two polarization directions by using the imaging device, An imaging unit that acquires the light of the polarization component as a parallax image, an optical member that forms the superimposed image on the imaging unit, and a region where the superimposed image is branched into two images. Split polarization means. According to this, as described in the above embodiment, the reflected light from the surface in the oblique direction can be polarized by the imaging unit at 45 degrees from the incident position and received by the light receiving element. As a result, it is possible to receive light of two polarization components having different polarization directions in directions orthogonal to each other of light incident from the same optical path. As a result, the difference in luminance between the two lights received by the light receiving element can be substantially eliminated, and the difference in polarization between the two polarization components that are different from each other in the direction in which the incident light is orthogonal to each other substantially disappears, and the reflected light from the surface in the oblique direction. It becomes difficult to receive the influence of the polarization difference caused by.
(Aspect 9)
In (Aspect 8), two images having parallax are formed by branching the image for each polarization direction from the image captured by the imaging unit, and the distance to the subject is calculated by the parallax between the two formed images. Distance calculation means is provided. According to this, as described in the above embodiment, when a stereo camera is used as an in-vehicle camera, reflected light from a surface oblique to the road surface is polarized at 45 degrees from the incident position on the imaging unit. The light receiving element can receive light. As a result, it is possible to receive light of two polarization components having different polarization directions in directions orthogonal to each other of light incident from the same optical path. As a result, the difference in luminance between the two lights received by the light receiving element can be substantially eliminated, and the difference in polarization between the two polarization components that are different from each other in the direction in which the incident light is orthogonal to each other substantially disappears, and the reflected light from the surface in the oblique direction. It becomes difficult to receive the influence of the polarization difference caused by. Therefore, the accuracy of the corresponding pixel search can be improved by the matching process in the stereo camera, and the accuracy of the distance calculation by the distance calculation means can be increased.
(Aspect 10)
In (Aspect 8), the polarization multiplexing means includes a polarization beam splitter and a mirror. According to this, as described in the above embodiment, the left and right optical path lengths can be made substantially the same with a simple configuration, and parallax can be obtained in the same manner as in a normal stereo camera.
(Aspect 11)
In (Aspect 8), the polarization multiplexing means makes the optical path lengths in the optical paths of the two images substantially the same. According to this, as described in the above embodiment, the parallax can be obtained by simply searching only the pixels in the horizontal direction at the time of the parallax calculation, as in the case of a normal stereo camera.
(Aspect 12)
The moving body includes the stereo camera according to any one of (Aspect 8) to (Aspect 11). According to this, as described in the above embodiment, not only image information in front of the vehicle but also distance information to the preceding vehicle and pedestrian in front of the vehicle can be acquired. It is possible to ensure driving safety, such as giving an early warning.

DESCRIPTION OF SYMBOLS 1 Image pick-up device 100 Image pick-up part 101 Image pick-up element 102 Substrate 103 Birefringent plate 104 Area division filter 105 Birefringent plate 106 Birefringent plate 107 Birefringent plate 200 Optical filter part 201 Filter substrate 202 Polarizing filter layer 203 Filling layer 300 Stereo camera 301 Polarization Superimposing module 301-1 Polarizing beam splitter 301-2 Polarizing filter 301-3 Mirror 302 Lens 303 Filter 304 Imaging device 400 Stereo camera 401 Substrate 402 Imaging device 403 Optical filter 404 Imaging lens 405 Cross prism 406 Side surface 407 Side surface 408 Triangular prism 409 Triangular prism 410 Side 411 Mirror 412 Mirror 413 Substrate 414 Imaging element 415 Optical filter 416 Imaging lens 420 Light source 421 Windshield 422 D
423 Optical filter 424 Lens 431 Polarizing beam splitter film 432 Mirror surface 433 Mirror surface 434 Mirror surface 435 Optical diaphragm 450 Polarizing plate 450-1 Polarizing plate 450-2 Polarizing plate 500 Car 501 Stereo camera 502 Signal processing device

JP 2010-243463 A

Claims (11)

A polarization multiplexing unit that superimposes optical paths of two images having parallaxes having different polarization directions in directions orthogonal to each other, and an imaging device in which a plurality of light receiving elements that respectively receive light of two polarization components are arranged. An imaging unit having an optical member that forms an image superimposed on the imaging unit by the polarization multiplexing unit, and an area division that branches the superimposed image into two images in the two imaging regions of the imaging unit In a stereo camera comprising polarization means ,
The region dividing polarization unit arranges each polarizer region with respect to the arrangement of the light receiving elements , and transmits light of each polarization component incident from one optical path in each polarizer region corresponding to the polarization component of the light. A region dividing filter that transmits and splits into two polarized light components and emits the light to the light receiving element;
A stereo camera characterized in that a polarization transmission angle of the area dividing filter is 45 degrees with respect to an arrangement direction of pixels of the light receiving elements corresponding to horizontal and vertical . The stereo camera according to claim 1,
A birefringent plate is provided on the incident side of the region dividing filter to split light of two polarization components incident from one optical path, and the refraction direction of the birefringent plate is determined according to the polarization transmission direction of the region dividing filter. A stereo camera characterized by that. The stereo camera according to claim 2,
A stereo camera characterized in that an optical low-pass filter is provided in front of the birefringent plate. The stereo camera according to claim 3,
The optical low-pass filter includes the birefringent plate and a birefringent plate having a refractive direction of 45 degrees with respect to the refractive direction of the birefringent plate and different from the birefringent plate. Stereo camera characterized by The stereo camera according to any one of claims 2 to 4,
A stereo camera , wherein the material of the birefringent plate is quartz. The stereo camera according to any one of claims 2 to 5 ,
2. The stereo camera according to claim 1, wherein the birefringent plate is a combination of two birefringent layers whose refraction directions are different from each other by 90 degrees. The stereo camera according to any one of claims 1 to 6 ,
A stereo camera comprising a polarization filter that transmits and emits light of two polarization components having different polarization directions in directions orthogonal to each other with respect to a light receiving element corresponding to green . In the stereo camera according to any one of 請 Motomeko 1-7,
A distance calculation unit is provided that forms two images having a parallax by branching the image for each polarization direction from the image captured by the imaging unit, and calculates a distance to the subject based on the parallax between the two formed images. A stereo camera characterized by that. The stereo camera according to any one of claims 1 to 8 ,
The stereo camera includes a polarization beam splitter and a mirror. The stereo camera according to any one of claims 1 to 9 ,
A stereo camera characterized in that in the polarization multiplexing means, the optical path lengths in the optical paths of the two images are substantially the same. Moving body, characterized in that for mounting the stereo camera according to any one of claims 1 to 10.

Images