JP2004325397A - Ranging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ranging device which can extract only a luminescent spot of laser beam while removing disturbance light even if a measuring object dynamically shifts. <P>SOLUTION: The ranging device is provided with a laser irradiation means 1 irradiating the measuring object 3 with a laser beam 2, a wavelength selection means 5 selectively extracting both a first wavelength band including the wavelength of the above laser beam and a second wavelength band not including wavelength of the above laser beam. It also contains imaging means 8, 12 with the same visual field which use the light of wavelength element for the first or the second wavelength band selected by the above wavelength selection means to image each luminescent spot generated on the measuring object surface through laser beam irradiation by the above laser irradiation means, respectively, and then synchronize to download these two images, and computing means 17, 19 computing a distance from an imaging position to the measuring object based on the operation of difference between the two images obtained by the above imaging means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention irradiates a laser beam onto a measurement target, captures an image of a luminescent spot generated on the surface of the measurement target, and determines the distance from the image forming position of the luminescent spot on the imaging element surface to the measurement target. The present invention relates to a distance measuring device based on a triangulation method for measuring.
[0002]
[Prior art]
In the conventional distance measuring device, the laser light to be irradiated is pulsed, and the laser is repeatedly turned on and off at each readout cycle of the light receiving element. , The effect of disturbance light is removed (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-4-328408
[Problems to be solved by the invention]
However, in such a distance measuring device, when the object to be measured and the distance measuring device are relatively moving, the object moves during lighting and non-lighting. An image formed on the imaging element surface at each timing when the light is not lit is different. Therefore, when the difference calculation of the output signal of the image sensor detected at both timings is performed, the change in luminance due to the movement of the image is reflected in the calculation result, and not only the laser spot to be originally extracted but also the luminance difference due to the image shift is calculated. And the effect of removing disturbance light is lost.
[0005]
The present invention has been made in view of the above points, and a distance measuring apparatus capable of removing disturbance light and extracting only a bright point of a laser beam even when a measurement target dynamically moves. The purpose is to obtain.
[0006]
[Means for Solving the Problems]
A distance measuring apparatus according to the present invention includes a laser irradiating unit that irradiates a laser beam onto an object to be measured, a first wavelength range including a wavelength of the laser light, and a second wavelength range not including a wavelength of the laser light. And a wavelength selecting means for selectively extracting the light source, the luminescent spot having the same field of view, and a luminescent spot generated on the surface of the measuring object by the irradiation of the laser light by the laser irradiating means is selected by the wavelength selecting means. An imaging unit that forms an image with light of wavelength components in the first wavelength region and the second wavelength region and captures two images in synchronization with each other; and forms an image based on a difference operation between the two images obtained by the imaging unit. Calculating means for calculating the distance from the image position to the object to be measured.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a layout diagram for explaining a distance measuring apparatus according to Embodiment 1 of the present invention. The distance measuring device shown in FIG. 1 irradiates a laser beam 2 from a laser irradiating means 1 onto a measurement target 3, and a bright spot 2-1 is generated on the measurement target 3 by the laser beam 2. The bright spot 2-1 generated above is picked up by the camera unit 4 as an image pickup means.
[0008]
As shown in FIG. 2, the camera unit 4 includes a dichroic mirror 5 provided on an optical path for separating a wavelength component of light contributing to imaging when imaging the bright spot 2-1. A wavelength filter 6 for selectively extracting only a predetermined wavelength range (detection wavelength) including the wavelength of the laser light from the transmitted light, an imaging lens 7 for forming an image of the bright spot 2-1 and an object to be measured 3, an image sensor 8 that forms an image of the bright spot 2-1 generated by the wavelength filter 6 with the light of the wavelength component selected by the wavelength filter 6, a mirror 9 that bends the optical path, and a wavelength that is separated via the dichroic mirror 5. Wavelength filter 10 for selectively transmitting a wavelength range (reference wavelength) in which the wavelength of laser light is excluded from the light in the range, and an imaging lens for forming an image with light having a wavelength component transmitted through the wavelength filter 10. 11, and an imaging element 12 for imaging a bright point 2-1 that occurred on the surface of the measuring object 3 with light having a wavelength component selected by the wavelength filter 10.
[0009]
The camera unit 4 is connected to a signal pre-processing unit 18 that performs a difference calculation of pixel data according to output signals from the two image pickup devices 8 and 12, and outputs the difference image data from the signal pre-processing unit 18. The distance to the bright spot 2-1 is calculated by the distance calculation processing unit 19 which receives the input. Here, the signal pre-processing unit 18 includes an A / D converter 13 that converts an output signal from the image sensor 8 into a digital signal, and two scan period data of the output signal from the image sensor 8 for two cycles. A video memory 14 for sequentially storing, an A / D converter 15 for digitally converting an output signal from the image sensor 12, and a video for sequentially storing data of one scanning cycle of the output signal from the image sensor 12 for two periods. The memory includes a memory 16 and a difference calculation unit 17 that calculates a difference between data of corresponding pixels in the video memories 14 and 16. Reference numeral 20 denotes a synchronizing signal generating circuit for synchronizing the image capturing of the two image sensors 8 and 12.
[0010]
FIG. 3 is a diagram showing the correlation between the detection wavelength, the reference wavelength, and the wavelength separation characteristics of the dichroic mirror 5. 3, the horizontal axis 30 indicates the wavelength axis, the vertical axis 31 indicates the intensity axis, 32 indicates the detection wavelength which is the laser wavelength to be irradiated, and 34 indicates the reference wavelength. As shown in FIG. 3, the characteristics of the wavelength filter 6 are determined so that the emission wavelength of the irradiation laser is included in the transmission wavelength range of the transmission wavelength characteristic 33 of the wavelength filter 6, and the transmittance wavelength distribution 35 of the wavelength filter 10 is determined. The transmittance distribution of the wavelength filter 10 is set so that the emission wavelength of the irradiation laser light is not included therein. Further, the wavelength separation characteristic 36 of the dichroic mirror 5 has a characteristic of transmitting, reflecting, and separating the detection wavelength 32 and the reference wavelength 34, respectively.
[0011]
FIG. 4 is a diagram illustrating an image obtained in each wavelength band (detection wavelength, reference wavelength) and a difference result between the two images. The image 37 (the image output from the imaging device 8; the detected image) 37 obtained in the detection wavelength range shown in FIG. 4A includes a bright spot in the image of the bright spot 2-1 generated by the irradiation of the laser light 2. 38, an outline 39 of a structure or the like in the field of view of the camera is shown, and an image (reference image) 40 obtained in the reference wavelength region shown in FIG. The difference image 42 between the detected image and the reference image shown in FIG. 4C shows a bright spot 43 by laser irradiation extracted as a result of the difference operation between the two images.
[0012]
The operation will be described below. The laser light 2 emitted from the laser irradiation means 1 generates a bright spot 2-1 on the measurement target 3. The camera unit 4 that images the measurement target 3 is deviated from the irradiation axis of the laser light 2 so that the imaging position on the imaging element surface changes by a predetermined change due to a change in the distance to the bright spot 2-1. It is installed in a position. The camera unit 4 transmits and reflects the light from the bright spot 2-1 using the dichroic mirror 5 according to the wavelength range. The dichroic mirror 5 has a wavelength separation characteristic 36 as shown in FIG. 3, and transmits light of a longer wavelength including the wavelength of the laser, and reflects light of a shorter wavelength. The light transmitted through the dichroic mirror 5 transmits a narrow band light including the wavelength of the laser light 2 by the wavelength filter 6, and the image of the measurement target 3 is formed on the image sensor 8 by the imaging lens 7. On the other hand, as for the light reflected by the dichroic mirror 5, only a narrow band light (light having a reference wavelength 34 shown in FIG. 3) not including the wavelength of the laser light 2 is transmitted by the wavelength filter 10 via the mirror 9, and the imaging lens By 11, an image of the measurement object 3 is formed on the surface of the imaging element 12.
[0013]
The signal from the imaging element 8 is output as an image 37 (see FIG. 4A), and together with the outline 39 of the structure of the measurement target 3 (see FIG. 4A), the brightness generated by the irradiation of the laser beam 2 The point 2-1 also appears as a bright point 38 (see FIG. 4A) in the image. On the other hand, the signal from the image sensor 12 forms an image 40 (see FIG. 4B), and only the contour 41 of the structure of the measurement object (see FIG. 4B) appears in the image. An imaging optical system is constructed so that these two images have the same field of view, and the acquisition timing is synchronized by the synchronizing signal generation circuit 20, so that the images have the same field of view and the same timing.
[0014]
These two images are subjected to a difference operation by the difference operation unit 17, and as a result, an image 42 (see FIG. 4C) is obtained in which the background light is removed and there is no contour of the structure of the object to be measured. Only 43 (see FIG. 4C) is extracted. The distance calculation unit 19 obtains the coordinates of the bright spot 43 in the image, and calculates the distance to the measurement target.
[0015]
Therefore, according to the first embodiment, an imaging optical system capable of simultaneously acquiring the same field of view by the two imaging elements 8 and 12 is configured, and one of the imaging elements forms an image with light of a wavelength component including the wavelength of the irradiation laser light. An optical system is formed on the other image sensor so as to form an image with light having the wavelength of the irradiation laser light deviated, and the difference processing between the detected image in both wavelength ranges and the reference image is performed, thereby reducing the time. Image difference without deviation is possible, and even if the object to be measured is a moving object, background light can be removed.As a result, only bright spots can be extracted by laser irradiation, and are not affected by disturbance light. Stable ranging is possible.
[0016]
Embodiment 2 FIG.
Further, in performing the difference calculation between the detected image and the reference image, the output signal from the image sensor may be directly processed by the H / W in analog signal processing as it is. As shown in FIG. 5, output signals from both the detection and reference imaging elements 8 and 12 are input to a difference calculator 53 via buffer circuits 51 and 52, respectively. The signal pre-processing unit 54 may be configured to perform a difference operation on the obtained imaging signal and output the result.
[0017]
Embodiment 3 FIG.
As a configuration of an optical system for generating a detection image and a reference image having the same field of view, as shown in FIG. 6, a dichroic mirror 61 is provided between an imaging lens 60 and imaging elements 62 and 63 as an optical element that separates an optical path by wavelength. Is provided, the optical path is separated according to the wavelength, and the wavelength filters 6 and 7 and the imaging devices 62 and 63 are installed for each separated optical path. With such a configuration, the size and weight of the imaging optical system can be reduced, and the size of the apparatus can be reduced.
[0018]
Next, the operation will be described. A dichroic mirror 61 is installed between the imaging lens 60 and the image forming position, and transmits light including the wavelength of the laser light as shown by the wavelength separation characteristic 36 (see FIG. 3), and transmits light not including the wavelength of the laser. Reflect. The light transmitted through the dichroic mirror 61 is transmitted by the wavelength filter 6 so that light in a narrow band including the wavelength of the laser light 2 indicated by the transmission wavelength characteristic 33 (see FIG. 3) is transmitted. An image is formed. On the other hand, the light reflected by the dichroic mirror 61 is transmitted by the wavelength filter 7 in a narrow band not including the wavelength of the laser light 2 as shown in the transmittance wavelength distribution 35 (see FIG. 3). An image of the measurement object is formed on the surface.
[0019]
In Embodiments 1 and 3, the routes are separated by using dichroic mirrors. However, even if a half mirror having no wavelength separation characteristics is used, the brightness of an image to be formed is reduced, but the same effect is obtained. can get.
[0020]
Embodiment 4 FIG.
FIG. 7 is a layout diagram for explaining a distance measuring apparatus according to Embodiment 4 of the present invention. In the distance measuring apparatus shown in FIG. 7, the laser light from the laser irradiating means 1 is polarized by a polarizing plate 70 for selecting a polarization direction, and a polarized laser light 72 is irradiated on a measurement object 73. Here, 71 indicates the direction of the selected polarized light, and here, the light indicates the direction perpendicular to the paper surface. A bright spot 72-1 is generated on the measurement target 73 by the laser light 72, and the bright spot 72-1 generated on the measurement target 73 is captured by a camera unit 74 as an imaging unit. .
[0021]
As shown in FIG. 8, the camera unit 74 transmits a polarized light component in the same direction as the laser light 72 in order to separate a polarized light component of light contributing to imaging when imaging the bright spot 72-1. A polarizing beam splitter 75 provided on the optical path and having a function of reflecting a polarized light component in a direction orthogonal to 72, a polarizing beam splitter 75 as a polarization selecting means, an imaging lens 7 for forming an image of a luminescent spot 72-1; An imaging element 8 in which a luminescent spot 72-1 generated on the surface of the object 73 is imaged with light having a polarization component in the same direction as the laser beam 72 selected by the polarization beam splitter 75, and a mirror 9 for bending the optical path; An imaging lens 11 for forming an image with light having a polarization component orthogonal to the laser beam 72 reflected and separated by the polarization beam splitter 75, and a luminescent spot 72− generated on the surface of the measurement object 73. There is provided an imaging device 12 to be imaged by the optical polarization component perpendicular to the laser beam 72 reflected separated by the polarizing beam splitter 75. In FIG. 8, the other signal preprocessing unit 18, distance calculation processing unit 19, and synchronization signal generation circuit 20 are the same as those in the first embodiment shown in FIG.
[0022]
FIG. 9 is a diagram showing the relationship between the polarization characteristics of the irradiated laser light and the polarization characteristics of the scattered light generated from the measurement object. In FIG. 9, as a measurement object, a surface having a small roughness such as metal or resin and a smooth structure object 73-1 such as a metal or a resin, and an object 73-2 having a rough surface and a large roughness such as a tree or the ground are used as measurement objects. Scattered lights 80 and 81 are generated by the laser light 72 irradiated on the object 73-1 and scattered lights 82 and 83 are generated when the laser light 72 is irradiated on the object 73-2. I have. The arrows pointing in opposite two directions indicate that the polarized light component is generated in the horizontal direction on the paper surface, and the black circles indicate that the polarized light component is generated in the vertical direction with respect to the paper surface.
[0023]
FIG. 10 is a diagram showing the relationship between the images obtained by the respective image sensors 8 and 12 and their difference images. An image (image obtained by the imaging device 8; detected image) 84 obtained by light having a polarization component in the same direction as the irradiation laser light 72 shown in FIG. 10A includes an image of the object 73-1 serving as a measurement target. 10B, the outline 85 of the image 73, the luminescent spot 86 in the image generated by the irradiation of the object 73-1 with the laser beam 72, and the image 87 of the object 73-2 in the camera field of view are shown. An image (reference image) 88 obtained by light having a polarization component orthogonal to the irradiation laser light 72 includes an image contour 89 of the object 73-1 existing in the image visual field and an object 73-2 existing in the image visual field. An outline 90 of the image is shown, and a difference image 91 obtained as a result of the difference between the image 84 and the image 88 shown in FIG. 10C includes a bright point 92 due to laser irradiation extracted as a result of the difference operation between the two images. It is shown.
[0024]
FIG. 11 is a diagram showing the relationship between the images obtained by the respective image sensors 8 and 12 and the difference images when the laser light 72 irradiates the object 73-2. An image (image obtained by the imaging device 8; detected image) 84 obtained by light having a polarization component in the same direction as the irradiation laser light 72 shown in FIG. 11A shows an object 73-2 serving as a measurement target. An image outline 85, an image outline 87 of the object 73-2 in the field of view of the camera, and a bright spot 93 in the image of a bright spot generated by irradiating the object 73-2 with the laser beam 72 are shown in FIG. The image (reference image) 88 obtained by the polarized light component orthogonal to the irradiation laser beam 72 shown in b) includes the contour 89 of the object 73-1 existing in the image visual field and the object 73- The image 90 of FIG. 11 shows the outline 90 of the image 2, and the bright spot 94 in the image of the bright spot generated by irradiating the object 73-2 with the laser beam 72. The image 91 shown in FIG. The difference image obtained as a result of the 88 differences is shown. That.
[0025]
The operation will be described below. The laser beam 72 radiated from the laser radiating unit 1 and having its polarization direction selected is radiated on the measurement object 73 to generate a bright spot. The camera unit 74 that captures an image of the measurement target is installed at a position deviated from the laser irradiation axis so that the imaging position on the imaging element surface changes by a predetermined distance due to a change in the distance to the bright spot. . The camera unit 74 has a characteristic of transmitting light from a bright spot using a polarization beam splitter 75 if the polarization direction is the same as that of the laser light 72 and reflecting the light if the polarization direction is orthogonal. The transmitted light forms an image of the measurement object on the image sensor 8 by the image pickup lens 7. On the other hand, the reflected light causes the imaging lens 11 to form an image of the measurement target on the imaging element 12.
[0026]
If the object to be measured is a metal, glass, resin, or other surface with small surface roughness and a smooth surface with a curvature like a sphere or cylindrical object, and the laser is irradiated, the imaging system receives specularly reflected light. The reflected lights 80 and 81 reflected and received from the measurement object preserve the polarization of the irradiation laser light. On the other hand, when an object whose surface roughness is large and rough is irradiated with laser light, the reflected lights 82 and 83 from the surface lose the polarization of the irradiated laser light, and are reflected in the same direction and the orthogonal direction as the laser light. The light is a mixture of polarized light. In addition, the reflected light from the object due to the irradiation of sunlight usually becomes a light in which the polarization property is broken and polarized lights in various directions are mixed.
[0027]
For this reason, a signal from the imaging element 8 in which the polarization direction of light contributing to imaging is the same as that of the irradiation laser light is output as an image 84 (see FIG. 10A), and the contour 85 of the measurement object is output. At the same time, the bright spot 86 generated by the irradiation of the laser light 2 and the surrounding structures also appear during the imaging of the image 87 by the sun irradiation. On the other hand, a signal from the imaging device 12 in which the polarization direction of light contributing to imaging is orthogonal to the irradiation laser forms an image 88 (see FIG. 10B), and the object 89 as a measurement target and other general structures Only 90 appears in the image. An imaging optical system is constructed so that these two images have the same field of view, and the acquisition timing is synchronized by the synchronizing signal generation circuit 20, so that the images have the same field of view and the same timing.
[0028]
These two images are subjected to a difference operation by the difference operation unit 17, and as a result, an image 91 is obtained in which the background light is removed and there is no outline of the structure of the object to be measured, and only the bright spot 92 by the laser is extracted. The distance calculation unit 19 calculates the coordinates of the bright spot 92 in the image, and calculates the distance to the measurement target.
[0029]
As described above, when the surface of the object to be measured is smooth or the surface has a curvature, and the reflected light from the surface is an object that retains the polarization characteristics of the irradiation laser light, the same field of view can be acquired simultaneously by the two imaging devices. An imaging optical system is formed, and one of the imaging devices forms an image with light having the same polarization component of the irradiation laser light, and the other imaging device forms an image with light having a polarization component in a direction orthogonal to the irradiation laser light. By configuring the optical system as described above and performing the difference processing between the detection image and the reference image based on the light in both polarization directions, it is possible to extract only the bright spot by laser irradiation even if the measurement target is a moving object. In addition, stable distance measurement that is not affected by disturbance light can be performed.
[0030]
Embodiment 5 FIG.
As a configuration of an optical system for generating a detection image and a reference image having the same field of view, as shown in FIG. 12, a polarization beam splitter is provided between an imaging lens 60 and imaging elements 101 and 102 as an optical element for separating an optical path by polarized light. By providing 100, light is separated according to the polarization direction, and the imaging devices 101 and 102 are installed for each separated optical path. By adopting such a configuration, it is possible to form an image on each of the imaging element surfaces, and it is possible to reduce the size and weight of the imaging optical system, thereby realizing a reduction in the size of the apparatus.
[0031]
In the fourth and fifth embodiments, a polarization beam splitter that transmits and reflects light according to the polarization direction is used to separate the optical path. However, the same effect can be obtained by using a half mirror and an analyzer. In addition, the polarization component was selected using a polarizer for the light emitted from the light source, but it is clear that equivalent effects can be obtained without the polarizer if the light source itself has linear polarization characteristics. .
[0032]
Next, the operation will be described. The polarization beam splitter 100 is installed between the imaging lens 60 and the image forming position, transmits polarized light in the same direction as the laser light, and reflects polarized light orthogonal to the laser light. The light transmitted through the polarization beam splitter 100 forms an image on the image sensor 101. On the other hand, the light reflected by the polarization beam splitter 100 forms an image of the measurement object on the surface of the element 102.
[0033]
With such a configuration, the size and weight of the imaging optical system can be reduced.
[0034]
【The invention's effect】
As described above, according to the present invention, it is possible to remove the disturbance light and extract only the bright spot of the laser light even when the measurement target moves dynamically.
[Brief description of the drawings]
FIG. 1 is a layout diagram for explaining a distance measuring apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a connection diagram of an internal configuration of the camera unit 4 shown in FIG. 1 and a signal preprocessing unit 18, a distance calculation processing unit 19, and a distance calculation processing unit 20.
FIG. 3 is a diagram showing a correlation between a detection wavelength, a reference wavelength, and a wavelength separation characteristic of a dichroic mirror 5;
FIG. 4 is a diagram showing an image obtained in each wavelength band (detection wavelength, reference wavelength) and a difference result between the two images.
FIG. 5 is a configuration diagram of a signal preprocessing unit according to a second embodiment of the present invention.
FIG. 6 is a configuration diagram of an optical system for generating a detection image and a reference image having the same field of view according to Embodiment 3 of the present invention.
FIG. 7 is a layout diagram for explaining a distance measuring apparatus according to Embodiment 4 of the present invention.
8 is a connection diagram of the internal configuration of the camera unit 74 shown in FIG. 7 and the signal preprocessing unit 18, the distance calculation processing unit 19, and the distance calculation processing unit 20.
FIG. 9 is a diagram showing a relationship between a polarization characteristic of a laser beam to be irradiated and a polarization characteristic of scattered light generated from an object to be measured.
FIG. 10 is a diagram showing a relationship between an image obtained by each of the imaging elements 8 and 12 and a difference image thereof.
FIG. 11 is a diagram showing a relationship between images obtained by the respective image sensors 8 and 12 and a difference image thereof when a laser beam 72 irradiates an object 73-2.
FIG. 12 is a configuration diagram of an optical system for generating a detection image and a reference image having the same field of view according to Embodiment 5 of the present invention.
[Explanation of symbols]
Reference Signs List 1 laser irradiation means, 2 laser light, 2-1 luminescent spot, 3 measurement object, 4 camera unit, 5 dichroic mirror, 6 wavelength filter, 7 imaging lens, 8 imaging device, 9 mirror, 10 wavelength filter, 11 imaging lens , 12 image sensor, 18 signal preprocessing unit, 19 distance operation processing unit, 13 A / D conversion unit, 14 video memory, 15 A / D conversion unit, 16 video memory, 17 difference operation unit, 20 synchronization signal generation circuit, 51, 52 buffer circuit, 53 difference operation unit, 54 signal preprocessing unit, 60 imaging lens, 61 dichroic mirror, 62, 63 imaging device, 70 polarizing plate, 72 laser light, 72-1 luminescent spot, 73 measurement object, 74 camera unit, 75 polarizing beam splitter, 100 polarizing beam splitter, 101, 102 imaging device.

Claims (4)

Laser irradiation means for irradiating a laser beam onto the object to be measured,
Wavelength selection means for selectively extracting a first wavelength range including the wavelength of the laser light and a second wavelength range not including the wavelength of the laser light,
A luminescent spot having the same field of view and generated on the surface of the object to be measured by the irradiation of the laser light by the laser irradiating means is selected from the wavelengths of the first wavelength range and the second wavelength range selected by the wavelength selecting means. Imaging means for forming two images in synchronization with the light of the components,
Calculating means for calculating the distance from the image forming position to the object to be measured based on the difference calculation between the two images obtained by the imaging means. The distance measuring device according to claim 1,
The wavelength selecting means includes an optical element that separates an optical path according to a wavelength,
The imaging means includes two imaging elements,
A distance measuring apparatus, wherein the two image sensors are installed at image forming positions of respective optical paths separated via the optical element. A polarizing plate for selecting a polarization direction,
Laser irradiating means for irradiating a laser beam in a selected polarization direction on the measurement object via the polarizing plate,
Polarization selecting means for selecting a first polarization component in the same direction as the irradiation laser light and a second polarization component orthogonal to the irradiation laser light,
A first polarized light component and a second polarized light component, which have the same field of view and have a bright spot generated on the surface of the object to be measured by laser light irradiation by the laser irradiation means, selected by the polarization selection means; Imaging means for forming two images in synchronization with each other,
Calculating means for calculating the distance from the image forming position to the object to be measured based on the difference calculation between the two images obtained by the imaging means. The distance measuring device according to claim 3,
The wavelength selecting means includes an optical element that separates an optical path by polarized light,
The imaging means includes two imaging elements,
A distance measuring apparatus, wherein the two image sensors are installed at image forming positions of respective optical paths separated via the optical element.

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