JP2021012055A - Distance measuring device - Google Patents

Abstract

To provide a distance measuring device that can achieve wide-range, high-accuracy distance measurement with a smaller scale configuration.SOLUTION: A distance measuring device 1 has an illumination optical system unit 10 and a light receiving optical system unit 30. The illumination optical system unit 10 has a first light source 12, a second light source 14, a plurality of lenses 16, and an optical path separation element 18. An illumination optical system 20 has a first optical system 22 through which only light from the first light source 12 passes, a second optical system 24 through which only light from the second light source 14 passes, and a third optical system 26 through which the light from the first light source 12 and the light from the second light source 14 pass. The light from the first light source 12 is incident on the third optical system 26 through the first optical system 22 and the optical path separation element 18, and the light from the second light source 14 is incident on the third optical system 26 through the second optical system 24 and the optical path separation element 18.SELECTED DRAWING: Figure 1

Description

The present invention relates to a ranging device.

As a technique for measuring a three-dimensional object or a scene, there is a distance measurement technique (stereo distance measurement technique) using a stereo image. In this stereo ranging technology, cameras are arranged at a plurality of different viewpoints, shooting is performed so that the shooting ranges overlap, and corresponding points are detected between the shot images. The distance from the camera to the corresponding point is measured based on the parallax corresponding to the corresponding point.

In the stereo ranging technology, in a system composed of a plurality of cameras with a normal angle of view, only the shooting range is the range that can measure the distance. Therefore, in order to enable a wider range of measurement, for example, Patent Document 1 provides a technique in which 12 stereo camera units are attached to each surface of a dodecahedron and color images and distance information in all directions can be acquired in real time. Has been described. Further, by using a plurality of omnidirectional cameras composed of two fisheye lenses arranged so that the incident surfaces are opposite to each other as in Patent Document 2 and Patent Document 3, the number of cameras can be reduced in all directions. A configuration that enables distance measurement is already known.

However, in the conventional technique, in order to improve the amount of light at the time of distance measurement, distance measurement is performed by using a large-scale device that combines a large-scale lighting mechanism with a photographing mechanism. Further, in the conventional technique, the distance measurement accuracy may be lowered due to the illumination parallax due to the illumination mechanism. Therefore, with the conventional technology, it has been difficult to expand the range of distance measurement and improve the accuracy with a small-scale configuration.

The present invention has been made in view of the above, and an object of the present invention is to enable wide-range and high-precision distance measurement to be performed in a smaller configuration.

In order to solve the above-mentioned problems and achieve the object, the present invention is a distance measuring device including an illumination optical system unit and a light receiving optical system unit, wherein the illumination optical system unit is a first light source. The illumination optical system includes an illumination optical system including a second light source, a plurality of lenses, and an optical path separation element, and the illumination optical system is a first optical system through which only light from the first light source passes. A second optical system through which only the light from the second light source passes, and a third optical system through which the light from the first light source and the light from the second light source pass. Then, the light from the first light source enters the third optical system via the first optical system and the optical path separation element, and the light from the second light source is the second light source. It is characterized in that it is incident on the third optical system via the optical system and the optical path separating element.

According to the present invention, wide range and high accuracy distance measurement can be performed in a smaller configuration.

FIG. 1 is an overall configuration diagram of a distance measuring device according to this embodiment. FIG. 2 is a schematic view of an example of the illumination optical system unit according to the present embodiment. FIG. 3 is a diagram showing an example of the relationship between the amount of light received by the light receiving optical system unit according to the present embodiment and the error of distance measurement. FIG. 4A is an explanatory diagram of the shape of the laser array element according to the present embodiment. FIG. 4B is an explanatory diagram of the shape of the laser array element according to the present embodiment. FIG. 5 is a diagram showing an example of the spectral distribution of the optical path separation element according to the present embodiment.

Hereinafter, embodiments of the ranging device according to the present invention will be described in detail with reference to the drawings. Further, the present invention is not limited by the following embodiments, and the components in the following embodiments include those easily conceived by those skilled in the art, substantially the same, and so-called equivalent ranges. Is included. Furthermore, various omissions, substitutions, changes and combinations of components can be made without departing from the gist of the following embodiments.

FIG. 1 is an overall configuration diagram of a distance measuring device according to this embodiment.

The distance measuring device 1 takes a picture in a state where the shooting space including the subject is irradiated with light, measures the distance to one or more subjects (including an object, a building, etc.) included in the shooting space, and measures the distance. It is a device that obtains three-dimensional distance data.

The distance measuring device 1 includes an illumination optical system unit 10 and a light receiving optical system unit 30.

The light receiving optical system unit 30 photographs the photographing space irradiated with light by the illumination optical system unit 10 and obtains three-dimensional distance data of the photographing space. The three-dimensional distance data is used to derive the distance to a subject (object, building, etc.) included in the shooting space. The light receiving optical system unit 30 is, for example, a three-dimensional restoration camera using a ToF (Time of Flight) method. The details of the light receiving optical system unit 30 will be described later.

The illumination optical system unit 10 is a device that irradiates a photographing space with light at the time of photographing by the light receiving optical system unit 30. That is, the illumination optical system unit 10 is applied to a three-dimensional restoration camera or the like using the ToF method.

FIG. 2 is a schematic view of an example of the illumination optical system unit 10. The illumination optical system unit 10 has an illumination optical system 20. The illumination optical system 20 includes a first light source 12, a second light source 14, a plurality of lenses 16, and an optical path separation element 18.

The first light source 12 and the second light source 14 are light sources that emit light. In the present embodiment, the first light source 12 and the second light source 14 have an array configuration in which a plurality of laser elements are arranged along a two-dimensional plane. That is, the first light source 12 and the second light source 14 are surface-emitting light sources. The first light source 12 and the second light source 14 are, for example, a VCSEL (Vertical Cavity Surface Emitting Laser).

The optical path separation element 18 has a beam split structure that separates incident light into transmission and reflection according to the polarization direction.

The illumination optical system 20 is a wide-angle lens (so-called fisheye lens) corresponding to an angle of view exceeding 180 degrees. The illumination optical system 20 includes a first optical system 22, a second optical system 24, and a third optical system 26.

The first optical system 22 is an optical system through which only the light from the first light source 12 passes. The second optical system 24 is an optical system through which only the light from the second light source 14 passes. The third optical system 26 is an optical system through which both the light from the first light source 12 and the light from the second light source 14 pass.

The first optical system 22 and the second optical system 24 are optical systems having positive power as a whole. Further, the first optical system 22 and the second optical system 24 each constitute a straight optical system.

Specifically, the first optical system 22 has a plurality of lenses 16 arranged in a direction away from the side closer to the first light source 12. Specifically, in the first optical system 22, the lens 16A, the lens 16B, the lens 16C, the lens 16D, and the lens 16E are arranged in series in this order from the side closer to the first light source 12 toward the side away from the first light source 12. ing.

The lens 16A is a biconvex lens made of a glass material and having aspherical surfaces on both sides. The lens 16B is a biconcave lens made of a glass material and having spherical surfaces on both sides. The lens 16C is a biconvex lens made of a glass material and having spherical surfaces on both sides. The lens 16D is a biconvex lens made of a glass material and having aspherical surfaces on both sides. The lens 16E is a biconvex lens made of a glass material and having spherical surfaces on both sides. The lens 16D and the lens 16E form a bonded lens bonded on the lens surface.

The first light source 12 may be arranged on the image plane (imaging position) of the first optical system 22.

The second optical system 24 has a plurality of lenses 16 arranged in a direction away from the side closer to the second light source 14. Specifically, in the second optical system 24, the lens 16F, the lens 16G, the lens 16H, the lens 16I, and the lens 16J are arranged in series in this order from the side closer to the second light source 14 toward the side away from the second light source 14. ing.

The lens 16F is a biconvex lens made of a glass material and having aspherical surfaces on both sides. The lens 16G is a biconcave lens made of a glass material and having spherical surfaces on both sides. The lens 16H is a biconvex lens made of a glass material and having spherical surfaces on both sides. The lens 16I is a biconvex lens made of a glass material and having aspherical surfaces on both sides. The lens 16J is a biconvex lens made of a glass material and having spherical surfaces on both sides. The lens 16I and the lens 16J form a bonded lens bonded on the lens surface.

The second light source 14 may be arranged on the image plane (imaging position) of the second optical system 24.

The first optical system 22 and the second optical system 24 are in directions in which their respective optical axes (the optical axis A1 of the first optical system 22 and the optical axis A2 of the second optical system 24) are orthogonal to each other. It is arranged like this. Further, in the first optical system 22 and the second optical system 24, the intersection of each of these optical axes is on a prism arranged at an angle of 45 ° with respect to these optical axes in the optical path separation element 18. It is arranged so as to be.

In this embodiment, the polarizing plate 12A is provided on the light emitting surface of the first light source 12. Similarly, a polarizing plate 14A is provided on the light emitting surface of the second light source 14. The polarizing plate 12A and the polarizing plate 14A transmit light having different polarizing components. For example, the polarizing plate 12A and the polarizing plate 14A transmit P-polarized light or S-polarized light.

In the present embodiment, a case where the polarizing plate 12A P-polarizes the light from the first light source 12 and transmits it to the first optical system 22 will be described as an example. Further, in the present embodiment, the case where the polarizing plate 14A S-polarizes the light from the second light source 14 and transmits it to the second optical system 24 will be described as an example. The polarizing plate 12A may be S-polarized and the polarizing plate 14A may be P-polarized.

In the present embodiment, the optical path separating element 18 transmits the light that has reached the optical path separating element 18 from the first light source 12 via the polarizing plate 12A and the first optical system 22, and is polarized from the second light source 14. The light that reaches the optical path separation element 18 via the plate 14A and the second optical system 24 is reflected in the direction corresponding to the optical axis A0 of the third optical system 26.

The third optical system 26 is an optical system through which both the light from the first light source 12 and the light from the second light source 14 pass.

The third optical system 26 is an optical system having negative power as a whole. Specifically, in the third optical system 26, the lens 16L and the lens 16K are arranged in series in this order in a direction away from the first light source 12 side. The lens 16L is a negative meniscus lens made of a glass material and having aspherical surfaces on both sides. The lens 16K is a negative meniscus lens made of a glass material and having spherical surfaces on both sides.

In the present embodiment, the case where the optical axis A0 of the third optical system 26 coincides with the optical axis A1 of the first optical system 22 will be described as an example. Further, the optical axis A0 of the third optical system 26 will be described as intersecting the optical axis A2 of the second optical system 24 perpendicularly at the position of the optical path separation element 18.

A parallel flat plate PP is provided between the third optical system 26 and the optical path separation element 18. The parallel flat plate PP is an optical member having a plane perpendicular to the optical axis A0 and having a refractive index of a glass material.

In the illumination optical system unit 10 configured as described above, the light from the first light source 12 enters the third optical system 26 via the first optical system 22 and the optical path separation element 18, and the third The photographing space by the light receiving optical system unit 30 is irradiated through the optical system 26 of the above. On the other hand, the light from the second light source 14 enters the third optical system 26 via the second optical system 24 and the optical path separation element 18, and the light receiving optical system unit 30 passes through the third optical system 26. The shooting space is illuminated by.

Therefore, in the illumination optical system unit 10 of the present embodiment, the light emitted from two different light sources (the first light source 12 and the second light source 14) is placed in the photographing space in a state where the same optical axis A0 is set. Be irradiated.

By making the light from two different light sources (the first light source 12 and the second light source 14) the same optical axis A0, that is, coaxial, it is possible to irradiate the shooting space with highly accurate and large amount of light. .. Further, by making the light from two different light sources (the first light source 12 and the second light source 14) have the same optical axis A0, that is, coaxial, the light from the two light sources is irradiated with the same optical axis. It is possible to suppress the influence of illumination disparity.

FIG. 3 is a diagram showing an example of the relationship between the amount of light received by the light receiving optical system unit 30 and the distance measurement error. As described above, the illumination optical system unit 10 of the present embodiment is applied to a three-dimensional restoration camera or the like using the ToF method. The three-dimensional restoration camera is an example of the light receiving optical system unit 30. Depending on how the light from the illumination optical system unit 10 hits when the light receiving optical system unit 30 shoots, the shadow appearance, brightness, and the like of the subject in the shooting space change. Therefore, in the prior art, there is a case where an error occurs in the distance measurement by using the three-dimensional distance data obtained by shooting under such a changing situation for the distance measurement.

On the other hand, in the present embodiment, the illumination optical system unit 10 irradiates the photographing space with light from two different light sources (first light source 12, second light source 14) with the same optical axis A0.

Therefore, the illumination optical system unit 10 of the present embodiment can suppress the influence of the illumination parallax, and can irradiate the photographing space with highly accurate light in which the influence of the illumination parallax is suppressed.

Further, by irradiating light from the first light source 12 and the second light source 14 with the same timing, the amount of irradiation light to the photographing space is simply doubled. Therefore, the S / N ratio can be improved, and the distance can be derived with high accuracy from the three-dimensional distance data.

It is preferable that the laser array elements of the first light source 12 and the second light source 14 are arranged in a circular shape, respectively.

4A and 4B are explanatory views of the shapes of the laser array elements of the first light source 12 and the second light source 14.

FIG. 4A is a top view showing the positional relationship between the first optical system 22 and the second optical system 24 and the first light source 12 and the second light source 14. FIG. 4B is a plan view of the light emitting surfaces of the first light source 12 and the second light source 14.

As shown in FIGS. 4A and 4B, the laser array elements constituting each of the first light source 12 and the second light source 14 have a circular shape or a plurality of different radii along the two-dimensional plane of the light emitting surface. It is preferable that the ring is arranged concentrically.

As the number of laser array elements arranged increases, power and heat generation are accompanied. Therefore, it is not preferable to arrange the laser element in a region where light cannot be guided by the illumination optical system 20. Therefore, the first light source 12 and the second light source 14 have a configuration in which a plurality of rings having a circular shape or different radii are arranged concentrically according to the illumination optical system 20 which is a wide-angle lens or a fisheye lens. It is preferable to have.

Further, in this case, it is preferable that the laser array elements are distributed in a region equal to or higher than the effective image height of the optical system corresponding to each of the first light source 12 and the second light source 14. The optical system corresponding to the first light source 12 is an optical system through which the light from the first light source 12 passes, and is an optical system including the first optical system 22 and the third optical system 26 (FIG. 6). See also 2). The optical system corresponding to the second light source 14 is an optical system through which the light from the second light source 14 passes, and is an optical system including the second optical system 24 and the third optical system 26 (FIG. 6). See also 2).

A wide range of laser array elements of the first light source 12 and the second light source 14 are arranged in a circular shape or a plurality of circular rings concentrically according to the illumination optical system 20 which is a wide-angle lens or a fisheye lens. It is considered that the effective image height of the illumination optical system 20 capable of irradiating light is circular due to the influence of barrel distortion. Therefore, it is preferable that the laser array elements constituting each of the first light source 12 and the second light source 14 are distributed in a region equal to or higher than the effective image height of the illumination optical system 20.

Further, it is preferable that the emission angles of the first light source 12 and the second light source 14 are narrower as they move away from the optical axis of the corresponding optical system.

Specifically, it is assumed that the laser array elements constituting the first light source 12 and the second light source 14 have a configuration in which a plurality of rings having different radii are arranged concentrically. In this case, the laser array element forming the ring having a smaller radius (closer to the center) has a larger emission angle with respect to the center, and the laser array element forming the ring having a larger radius (outer). It may be arranged so that the emission angle is narrower with respect to the center. The center is the center of a plurality of concentric circles. For example, among the plurality of rings, the emission angle with respect to the center of the laser array element forming the ring having the smallest radius is set to about 30 deg, and the emission angle with respect to the center of the laser array element forming the ring having the largest radius is set to about 30 deg. It may be about 20 deg.

When the emission angles of the first light source 12 and the second light source 14 are narrow enough to be far from the optical axis of the corresponding optical system, the decrease in the amount of light in the peripheral portion of the photographing space is suppressed and the distance measurement is performed. It is possible to suppress a decrease in the possible region and suppress an error.

In the above description, the first light source 12 and the second light source 14 are described as an example in which the polarizing plate 12A and the polarizing plate 14A irradiate light having different polarization components from each other. However, the first light source 12 and the second light source 14 may emit light having different wavelengths from each other.

For example, it is assumed that the optical path separation element 18 is used as the optical path separation element 18 that transmits light having a specific wavelength or higher and reflects light having a wavelength lower than the specific wavelength. In this case, the first light source 12 that emits light of a specific wavelength or higher is used as the first light source 12, and the second light source 14 that emits light of a specific wavelength or less is used as the second light source 14. Just do it. A first light source 12 that emits light of a specific wavelength or less may be used, and a second light source 14 that emits light of a specific wavelength or more may be used.

Specifically, for example, it is assumed that an infrared reflection coat (IRC) is used as the optical path separation element 18. FIG. 5 is a diagram showing an example of the spectral distribution of the optical path separation element 18 in this case. In this case, for example, a first light source 12 that emits visible light and a second light source 14 that emits infrared light may be used.

In this way, by using the first light source 12 and the second light source 14 as light sources that emit light of different wavelengths, the light receiving optical system unit 30 is a photographing space irradiated with light of two different wavelengths. Can be photographed.

Return to FIG. 2 and continue the explanation. The first light source 12 and the second light source 14 may emit light at the same timing, or may emit light at different timings.

Specifically, the first light source 12 and the second light source 14 may be driven simultaneously or separately. By driving the first light source 12 and the second light source 14 at the same time and emitting light at the same timing, the amount of light emitted to the photographing space can be increased. On the other hand, since the first light source 12 and the second light source 14 are driven separately and emit light at different timings, the distance measuring device 1 having a configuration in which the power supply capacity is minimized can be obtained.

Further, the first light source 12 and the second light source 14 may be light sources that emit light having different wavelengths from each other, and the first light source 12 and the second light source 14 may emit light at different timings. .. In this case, the light receiving optical system unit 30 can perform different processes such as taking an image when irradiating visible light and performing distance measurement when irradiating infrared light.

The explanation will be continued by returning to FIG. As described above, the light receiving optical system unit 30 may be a three-dimensional restoration camera using the ToF method. The light receiving optical system unit 30 preferably has the same configuration as the illumination optical system unit 10.

Specifically, the light receiving optical system unit 30 has a light receiving optical system 40. The light receiving optical system 40 includes a first light receiving element 32, a second light receiving element 34, a plurality of lenses 36, and a second optical path separating element 38.

The first light receiving element 32 and the second light receiving element 34 are image sensors. The first light receiving element 32 and the second light receiving element 34 take an image of the subject and generate an image by converting the light incident on the light receiving optical system unit 30 into an electric signal. The first light receiving element 32 and the second light receiving element 34 are realized by a solid-state image sensor such as a CCD (Charge-Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor, for example.

The second optical path separation element 38 has a beam split structure that transmits a part of the incident light and reflects a part of the incident light.

The light receiving optical system 40 is a wide-angle lens (so-called fisheye lens) corresponding to an angle of view exceeding 180 degrees. The light receiving optical system 40 includes a fourth optical system 42, a fifth optical system 44, and a sixth optical system 46.

The fourth optical system 42 is an optical system through which only the light reaching the first light receiving element 32 passes. The fifth optical system 44 is an optical system through which only the light reaching the second light receiving element 34 passes. The sixth optical system 46 is an optical system through which light reaching both the first light receiving element 32 and the second light receiving element 34 passes. That is, the light incident on the sixth optical system 46 is divided by the second optical path separation element 38, reaches the first light receiving element 32 via the fourth optical system 42, and is the fifth optical device. It reaches the second light receiving element 34 via the system 44.

The fourth optical system 42 and the fifth optical system 44 are optical systems having positive power as a whole. Further, the fourth optical system 42 and the fifth optical system 44 each constitute a straight optical system.

Specifically, the fourth optical system 42 has a plurality of lenses 36 arranged in a direction away from the side closer to the first light receiving element 32. Specifically, in the fourth optical system 42, the lens 36A, the lens 36B, the lens 36C, the lens 36D, and the lens 36E are arranged in series in this order from the side closer to the first light receiving element 32 toward the side away from the first light receiving element 32. Has been done.

The lens 36A is a biconvex lens made of a glass material and having aspherical surfaces on both sides. The lens 36B is a biconcave lens made of a glass material and having spherical surfaces on both sides. The lens 36C is a biconvex lens made of a glass material and having spherical surfaces on both sides. The lens 36D is a biconvex lens made of a glass material and having aspherical surfaces on both sides. The lens 36E is a biconvex lens made of a glass material and having spherical surfaces on both sides. The lens 36D and the lens 36E form a bonded lens bonded on the lens surface.

The first light receiving element 32 may be arranged on the imaging surface (imaging position) of the fourth optical system 42.

The fifth optical system 44 is formed by arranging a plurality of lenses 36 in a direction away from the side closer to the second light receiving element 34. Specifically, in the fifth optical system 44, the lens 36F, the lens 36G, the lens 36H, the lens 36I, and the lens 36J are arranged in series in this order from the side closer to the second light receiving element 34 toward the side away from the second light receiving element 34. Has been done.

The lens 36F is a biconvex lens made of a glass material and having aspherical surfaces on both sides. The lens 36G is a biconcave lens made of a glass material and having spherical surfaces on both sides. The lens 36H is a biconvex lens made of a glass material and having spherical surfaces on both sides. The lens 36I is a biconvex lens made of a glass material and having aspherical surfaces on both sides. The lens 36J is a biconvex lens made of a glass material and having spherical surfaces on both sides. The lens 36I and the lens 36J form a bonded lens bonded on the lens surface.

The second light receiving element 34 may be arranged on the imaging surface (imaging position) of the fifth optical system 44.

The fourth optical system 42 and the fifth optical system 44 are arranged so that their optical axes are orthogonal to each other. Further, in the fourth optical system 42 and the fifth optical system 44, the intersections of their respective optical axes are arranged at an angle of 45 ° with respect to these optical axes in the second optical path separation element 38. It is arranged so as to be on the prism.

In the present embodiment, the second optical path separation element 38 separates the light incident on the sixth optical system 46 into two, guides one light to the fifth optical system 44, and guides the other light to the fourth optical system 44. It leads to the optical system 42 of.

The sixth optical system 46 is an optical system through which both the light to the first light receiving element 32 and the light to the second light receiving element 34 pass.

The sixth optical system 46 is an optical system having negative power as a whole. Specifically, in the sixth optical system 46, the lens 36L and the lens 36K are arranged in series in this order in a direction away from the first light receiving element 32 side. The lens 36L is a negative meniscus lens made of a glass material and having aspherical surfaces on both sides. The lens 36K is a negative meniscus lens made of a glass material and having spherical surfaces on both sides.

In the present embodiment, the case where the optical axis of the sixth optical system 46 coincides with the optical axis of the fourth optical system 42 will be described as an example. Further, the optical axis of the sixth optical system 46 will be described as intersecting the optical axis of the fifth optical system 44 at the position of the second optical path separating element 38.

A parallel flat plate PP is provided between the sixth optical system 46 and the second optical path separation element 38. The parallel flat plate PP is an optical member having a plane perpendicular to the optical axis of the sixth optical system 46 and having a refractive index of a glass material.

In the light receiving optical system unit 30 configured as described above, the light to the first light receiving element 32 passes through the sixth optical system 46, the second optical path separation element 38, and the fourth optical system 42. It is incident on the first light receiving element 32. On the other hand, the light to the second light receiving element 34 enters the second light receiving element 34 via the sixth optical system 46, the second optical path separating element 38, and the fifth optical system 44.

By forming the light receiving optical system unit 30 in the same configuration as the illumination optical system unit 10 in this way, it is possible to use common parts in the light receiving optical system unit 30 and the illumination optical system unit 10. Therefore, it is possible to simplify the manufacturing process of the distance measuring device 1 and reduce the cost.

As described above, the distance measuring device 1 of the present embodiment includes an illumination optical system unit 10 and a light receiving optical system unit 30. The illumination optical system unit 10 includes a first light source 12, a second light source 14, a plurality of lenses 16, and an optical path separation element 18. The illumination optical system 20 includes a first optical system 22 through which only the light from the first light source 12 passes, a second optical system 24 through which only the light from the second light source 14 passes, and a first light source. It has a third optical system 26 through which the light from 12 and the light of the second light source 14 pass. The light from the first light source 12 enters the third optical system 26 via the first optical system 22 and the optical path separation element 18, and the light from the second light source 14 is the second optical system 24. And, it is incident on the third optical system 26 via the optical path separation element 18.

Therefore, in the distance measuring device 1 of the present embodiment, light from two different light sources (first light source 12 and second light source 14) can be applied to the photographing space with the same optical axis, and the illumination parallax can be obtained. The influence of can be suppressed. Further, in the distance measuring device 1, it is possible to suppress the scale-up of the distance measuring device 1 by irradiating the light from two different light sources (the first light source 12 and the second light source 14) coaxially. ..

Therefore, the distance measuring device 1 of the present embodiment can realize a wide range and highly accurate distance measurement with a smaller configuration.

1 Distance measuring device 10 Illumination optical system unit 12 First light source 14 Second light source 16 Lens 18 Optical path separation element 20 Illumination optical system 22 First optical system 24 Second optical system 26 Third optical system 30 Light receiving optics System unit 32 First light receiving element 34 Second light receiving element 36 Lens 38 Second optical path separation element 40 Light receiving optical system 42 Fourth optical system 44 Fifth optical system 46 Sixth optical system

Japanese Patent No. 3827912 Japanese Patent No. 5483027 Japanese Patent No. 501528

Claims (8)

A distance measuring device having an illumination optical system unit and a light receiving optical system unit.
The illumination optical system unit is
It has an illumination optical system having a first light source, a second light source, a plurality of lenses, and an optical path separating element.
The illumination optical system is
The first optical system through which only the light from the first light source passes, and
A second optical system through which only light from the second light source passes, and
It has a third optical system through which the light from the first light source and the light from the second light source pass.
The light from the first light source enters the third optical system via the first optical system and the optical path separation element, and then enters the third optical system.
The light from the second light source enters the third optical system via the second optical system and the optical path separating element.
A distance measuring device characterized by this. The first light source and the second light source are laser array elements.
The laser array elements are distributed in a region equal to or higher than the effective image height of the optical system corresponding to each of the first light source and the second light source.
The distance measuring device according to claim 1. Each of the first light source and the second light source has a configuration in which the laser array element is arranged in a circle or a plurality of rings having different radii are arranged concentrically.
2. The distance measuring device according to claim 2. The emission angles of the first light source and the second light source are narrower as they move away from the optical axis of the corresponding optical system, respectively.
The distance measuring device according to any one of claims 1 to 3, wherein the distance measuring device is characterized by the above. The first light source and the second light source emit light having different wavelengths from each other.
The distance measuring device according to any one of claims 1 to 4. The first light source and the second light source emit light at the same timing.
The distance measuring device according to any one of claims 1 to 5. The first light source and the second light source emit light at different timings.
The distance measuring device according to any one of claims 1 to 5. The light receiving optical system unit is
It has a light receiving optical system having a first light receiving element, a second light receiving element, a plurality of lenses, and a second optical path separating element.
The light receiving optical system is
A fourth optical system through which only light passes through the first light receiving element, and
A fifth optical system through which only light passes through the second light receiving element, and
It has a sixth optical system through which both the light to the first light receiving element and the light to the second light receiving element pass.
The light to the first light receiving element is incident on the first light receiving element via the sixth optical system, the second optical path separation element, and the fourth optical system.
The light to the second light receiving element is incident on the second light receiving element via the sixth optical system, the second optical path separation element, and the fifth optical system.
The distance measuring device according to any one of claims 1 to 7.

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