Lidar system

Abstract

Provided is a LiDAR system capable of measuring both a first field of view and a second field of view different from the first field of view while using laser light having wavelengths equal to or shorter than 1000nm that can be realized at low cost.SOLUTION: The LiDAR system 1 includes a silicon semiconductor-based light projecting module 2 that projects near infrared laser light having wavelengths equal to or shorter than 1000nm, a first optical scanning device 4 that reflects the laser light from the light projecting module 2 toward a second optical scanning device 5 while scanning the laser light in a first direction, and a second optical scanning device 5 that reflects the laser light from the first optical scanning device 4 to second field-of-view optical systems 6 and 7 for irradiating a first (near) field of view or a second (far) field of view different from the first field of view while scanning the laser light in a second direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a LiDAR (Light Detection And Ranging) system. [Background technology]

[0002] The following Patent Documents 1 and 2 disclose LiDAR systems. The principle of a LiDAR system is to measure the distance and direction to an object by measuring the time it takes for an irradiated laser beam to hit the object and bounce back. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6789926 [Patent Document 2] Patent No. 6697636 [Patent Document 3] Patent No. 7108789 [Patent Document 4] Patent No. 7200378 Summary of the Invention [Problem to be solved by the invention]

[0004] The laser light used in LiDAR systems is near-infrared (wavelength 700-2500 nm), but laser light with wavelengths of 905 nm or 1550 nm is commonly used. Silicon semiconductor lasers are generally used for 905 nm laser light, while compound semiconductor lasers are generally used for 1550 nm laser light. 905 nm laser light is more advantageous in terms of cost and power consumption, and the light-receiving device can also be manufactured from silicon semiconductors, which is cost-effective. On the other hand, 1550 nm laser light has the advantage of being less permeable to living organisms and less impactful on the retina, making it easier to increase the output.

[0005] The systems disclosed in Patent Documents 1, 3, and 4 above disclose using a 1550 nm laser beam to increase the signal-to-noise ratio by increasing the output, thereby enabling long-distance measurements. However, the 1550 nm laser beam projection device requires a fiber laser using a compound semiconductor, and the light-receiving device also requires a compound semiconductor, resulting in higher costs than using a 905 nm laser beam. Patent Documents 1, 2, and 3 also disclose the use of a 905 nm laser beam, but 905 nm laser beams are highly permeable to living organisms, making it difficult to increase the output considering their impact on the retina, making them unsuitable for long-distance measurements.

[0006] The object of the present disclosure is to provide a LiDAR system that can measure both a first field of view and a second field of view that is different from the first field of view, while utilizing laser light with a wavelength of 1000 nm or less, which can be realized at low cost. [Means for solving the problem]

[0007] The LiDAR system according to the present disclosure includes a silicon semiconductor-based light-projecting module that projects near-infrared laser light with a wavelength of 1000 nm or less; a first optical scanning element that directly or indirectly receives the laser light projected from the light-projecting module and scans it in a first direction while reflecting it toward a second optical scanning element; the second optical scanning element that scans the laser light reflected by the first optical scanning element in a second direction intersecting the first direction while selectively reflecting it toward a second field of view optical system for irradiation onto a first field of view or a second field of view different from the first field of view; an optical deflection element provided in the second field of view optical system that deflects the laser light reflected from the second optical scanning element toward the second field of view; and a light-receiving module that receives the laser light irradiated toward the first field of view by the second optical scanning element or the reflected laser light of the laser light irradiated from the second field of view optical system toward the second field of view.

[0008] The first optical scanning element may be a silicon semiconductor based single axis MEMS mirror.

[0009] The first field of view may be a near field of view with a wide field of view angle, and the second field of view may be a far field of view with a narrow field of view angle, and the second field of view optical system may further include a telephoto lens that passes the laser light deflected by the optical deflection element.

[0010] The second optical scanning element may be a rotating dihedral mirror that is rotated in one direction about a rotation axis perpendicular to the second direction. [Effects of the Invention]

[0011] The LiDAR system according to the present disclosure can measure both a first field of view and a second field of view that is different from the first field of view, while utilizing laser light with a wavelength of 1000 nm or less, which can be realized at low cost. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic side view of a LiDAR system according to an embodiment. [Figure 2] FIG. 2 is a schematic plan view of the LiDAR system. DETAILED DESCRIPTION OF THE INVENTION

[0013] A LiDAR system 1 according to an embodiment will be described below with reference to FIGS. 1 and 2. The LiDAR system 1 includes three sets of light-projecting and light-receiving modules 2 (2A to 2C) and a fixed mirror 3 (3A to 3C). As will be described in detail later, the LiDAR system 1 of this embodiment uses a MEMS mirror 4 for scanning the laser light in the second direction, i.e., the horizontal direction. The MEMS mirror 4 has the limitation that it cannot widen the scanning angle, so the LiDAR system 1 of this embodiment obtains a wide scanning angle by providing three sets of light-projecting and light-receiving modules 2 and a fixed mirror 3. How a wide scanning angle can be obtained will be described later with reference to FIG. 2 when explaining the MEMS mirror 4.

[0014] In the light-projecting / light-receiving module 2 of this embodiment, both the light-projecting section and the light-receiving section use silicon semiconductors, and the light-projecting section projects near-infrared laser light with a wavelength of 1000 nm or less, more specifically, a wavelength of 905 nm in this embodiment. The light-receiving section of the light-projecting / light-receiving module 2 also uses silicon semiconductors and receives reflected laser light of laser light emitted from the LiDAR system 1. Note that this embodiment employs the light-projecting / light-receiving module 2 in which the light-projecting section and light-receiving section are integrated, but it is also possible to provide a light-receiving module and a light-receiving module that is separate from the light-receiving module.

[0015] In this embodiment, three light-projecting / light-receiving modules 2 are provided to obtain a wide scanning angle. However, if multiple light-receiving modules are provided to obtain a wide scanning angle, the reflected laser light may be received by a single light-receiving module. In this case, an auxiliary optical element may be provided to optically deflect the reflected laser light toward the single light-receiving module. The fixed mirror 3 reflects the laser light projected from the light-projecting / light-receiving module 2 toward the first optical scanning element 4, and its reflective surface is fixed. In this embodiment, three fixed mirrors 3 are used to obtain a wide scanning angle, but the laser light may be projected directly from the light-projecting module to the first optical scanning element 4.

[0016] The LiDAR system 1 includes the above-described first optical scanning element 4, which in this embodiment is a silicon semiconductor-based one-axis MEMS mirror 4. The first optical scanning element 4, i.e., the MEMS mirror 4, directly or indirectly receives the laser light projected from the light projecting and receiving module 2, and reflects it toward the second optical scanning element 5 while scanning it in a first direction, i.e., the horizontal direction in this embodiment. In this embodiment, the MEMS mirror 4 indirectly receives the laser light projected from the light projecting and receiving module 2 via the fixed mirror 3, and reflects it toward the second optical scanning element 5 while scanning it in the horizontal direction.

[0017] Here, we will explain general matters regarding MEMS mirrors. MEMS mirrors are mirrors manufactured using MEMS (Micro Electro Mechanical Systems) technology. In the LiDAR systems disclosed in the above-mentioned Patent Documents 1 and 2, horizontal and vertical scanning of laser light is performed using silicon semiconductor-based MEMS mirrors. MEMS technology is a technology that integrates mechanical structural elements such as mirrors and their support and drive mechanisms, as well as associated electronic circuits, on a substrate using semiconductor manufacturing technology. MEMS devices can be broadly divided into those based on silicon semiconductors and those based on compound semiconductors. In general, silicon semiconductor-based MEMS devices can be manufactured at lower cost.

[0018] Laser beam steering methods can be broadly divided into mechanical and solid-state methods. The beam steering using the MEMS mirror mentioned above is a type of solid-state beam steering. In mechanical methods, laser beams are beam-steered using a polygon mirror or galvanometer mirror. Since a drive mechanism equipped with a motor is required to drive the polygon mirror or galvanometer mirror, mechanical beam steering devices are difficult to make small and lightweight. For this reason, solid-state beam steering methods that utilize semiconductor technology are being widely studied.

[0019] However, it is difficult to obtain a wide scanning angle with MEMS mirrors that use semiconductor technology compared to mechanical beam steering. Also, due to the physical properties of semiconductor wafers, it is difficult to fabricate large-area MEMS mirrors, making it impossible to increase the light-receiving area, resulting in an inferior signal-to-noise ratio (SN ratio) compared to mechanical beam steering. Note that a MEMS mirror that has a single scanning direction, i.e., one scanning axis, is called a 1-axis MEMS mirror. For example, a MEMS mirror with two scanning axes that can perform scanning in both horizontal and vertical directions is called a 2-axis MEMS mirror.

[0020] In this embodiment, a silicon semiconductor-based uniaxial MEMS mirror 4 is used as the first optical scanning element 4, but other types of optical scanning elements, such as a polygon mirror, may also be used as the first optical scanning element 4. However, as described above, polygon mirrors require a drive mechanism such as a motor, making it difficult to reduce their size and weight. Using a MEMS mirror 4 as the first optical scanning element 4 as in this embodiment facilitates reducing the size and weight of the LiDAR system 1. On the other hand, as described above, using a MEMS mirror 4 as the first optical scanning element 4 makes it difficult to obtain a wide scanning angle. Therefore, in this embodiment, three sets of light-emitting / light-receiving modules 2 and fixed mirrors 3 are provided, as shown in FIG. 2 .

[0021] 2, the laser light emitted from the central light-emitting / receiving module 2A is reflected by the central fixed mirror 3A onto the MEMS mirror 4 and is horizontally scanned by the MEMS mirror 4. The laser light reflected by the MEMS mirror 4 passes through a second optical scanning element 5 (described later) and is then emitted from the LiDAR system 1, and the horizontal scanning range corresponding to the central light-emitting / receiving module 2A is the central range within the horizontal scanning range of the LiDAR system 1.

[0022] The laser light emitted from the light-emitting / receiving module 2B arranged at the top in FIG. 2 is reflected by the corresponding fixed mirror 3B onto the MEMS mirror 4 and is horizontally scanned by the MEMS mirror 4. The direction in which the laser light from the fixed mirror 3B is reflected by the MEMS mirror 4 is downward in FIG. 2. Therefore, the upper light-emitting / receiving module 2B scans the lower range in FIG. 2 relative to the central horizontal scanning range corresponding to the central light-emitting / receiving module 2A. Similarly, the laser light emitted from the light-emitting / receiving module 2C arranged at the bottom in FIG. 2 scans the upper range in FIG. 2. By performing horizontal scanning while switching between the three light-emitting / receiving modules 2A to 2C, a wide horizontal scanning angle can be ensured for the LiDAR system 1.

[0023] In this embodiment, the MEMS mirror 4 is used for horizontal scanning, which requires high-speed scanning due to the reciprocating scanning. Because the MEMS mirror 4 does not require mechanical elements such as bearings, the LiDAR system 1 can have a longer lifespan than mechanical beam steering technologies such as polygon mirrors or galvanometer mirrors.

[0024] The laser light scanned horizontally by the MEMS mirror 4 is reflected toward the second optical scanning element 5. That is, the LiDAR system 1 includes the second optical scanning element 5. The second optical scanning element 5 reflects the laser light while scanning it in a second direction, i.e., a vertical direction, which intersects the first horizontal direction. In this embodiment, the second optical scanning element 5 is a rotary dihedral mirror 5 that rotates in one direction. The rotation axis of the rotary dihedral mirror 5 extends perpendicular to the second direction, i.e., extends perpendicular to the vertical direction. In simpler terms, in this embodiment, the rotation axis of the rotary dihedral mirror 5 extends in the horizontal direction. Both ends of the rotation axis are rotatably supported via bearings. The laser light reflected by the rotary dihedral mirror 5 that rotates around the horizontal rotation axis is scanned vertically and selectively reflected to a second field of view optical system for irradiating a first field of view or a second field of view different from the first field of view.

[0025] In this embodiment, the first field of view is a near-distance field of view with a wide field angle to be measured, and the second field of view is a far-distance field of view with a narrow field angle to be controlled. The field angle of the near-distance field is wider than that of the far-distance field. The near-distance field refers to an object to be measured at a distance of less than 150 m, and the far-distance field refers to an object to be measured at a distance of 150 m or more. The laser light reflected by the rotating dihedral mirror 5 is vertically scanned and either directly irradiated onto the near-distance field, which is the first field of view, or irradiated onto the far-distance field, which is the second field of view, via the second field optical system described below. The laser light irradiated onto the near-distance field or the far-distance field of view passes through the MEMS mirror 4, which is the first optical scanning element 4, and is therefore also horizontally scanned. The second field optical system includes at least an optical deflection element 6, and in this embodiment, also includes a telephoto lens 7.

[0026] The optical deflection element 6 of the second field of view optical system deflects the laser light reflected by the rotating dihedral mirror 5 to the second field of view, which is the long-distance field of view. In this embodiment, the optical deflection element 6 is a concave mirror 6, more specifically, a parabolic mirror 6. Note that a prism or the like may be used as the optical deflection element 6 instead of a mirror. In this embodiment, a laser beam with a wavelength of 905 nm, which has high biological transmittance, is used, and it is difficult to increase the output due to the impact on the retina of living organisms. Considering the field of view angle for the long-distance field of view, i.e., the scanning angle, and this biological transmittance, the second field of view optical system of the LiDAR system 1 of this embodiment also requires a telephoto lens 7.

[0027] In this embodiment, the rotating dihedral mirror 5 rotates at a constant rotational speed. Horizontal scanning by the MEMS mirror 4, which is the first optical scanning element 4, and vertical scanning by the rotating dihedral mirror 5, which is the second optical scanning element 5, are performed synchronously. The near field of view and the far field of view are scanned once each during a half rotation of the rotating dihedral mirror 5, i.e., a 180-degree rotation. Both sides of the rotating dihedral mirror 5 are flat mirrors, and scanning of the next near field of view and the next far field of view is performed during the next 180-degree rotation. Here, scanning of each field of view with respect to the rotation angle may be performed one-to-one, or a wider rotation angle may be assigned to one of the fields of view with emphasis placed on the other.

[0028] Furthermore, by controlling the projection of the laser light from the light projecting / receiving module 2, it is possible to focus scanning on one of the fields of view. For example, the LiDAR system 1 of this embodiment can focus scanning only on the near field of view by projecting all possible laser light in a single scan within the rotation angle range in which the laser light is irradiated from the rotating dihedral mirror 5 to the near field of view. In this embodiment, the rotating dihedral mirror 5 is rotated at a constant rotational speed. In this way, there is no fluctuation in rotational acceleration, making it easy to control the rotation of the rotating dihedral mirror 5, and it is possible to continuously rotate the rotating dihedral mirror 5 using a small motor. However, the rotational speed of the rotating dihedral mirror 5 may also be variably controlled.

[0029] A brushless motor with a rotation angle detection function is used as the motor that rotates the rotating dihedral mirror 5, making it easy to detect vertical scanning using the rotating dihedral mirror 5. Note that vertical scanning is unidirectional rather than reciprocating, and therefore does not require as high a scanning speed as horizontal scanning. In this embodiment, by using the rotating dihedral mirror 5, which rotates in one direction, for vertical scanning, which does not require as high a scanning speed as horizontal scanning, it is possible to prevent uneven wear on the bearings that support the rotation axis, thereby achieving a longer life for the LiDAR system 1. For example, while polygon mirrors used for reciprocating scanning are prone to uneven wear on the bearings that support their rotation axis, the rotating dihedral mirror 5 of this embodiment can solve this problem.

[0030] As described above, a brushless motor with a rotation angle detection function is used as the motor that rotates the rotating dihedral mirror 5, and vertical scanning by the rotating dihedral mirror 5 can be easily detected. On the other hand, a separate detection mechanism is required to detect horizontal scanning by the MEMS mirror 4. Therefore, in this embodiment, an angle sensor 8 for the MEMS mirror 4 is also provided.

[0031] The angle sensor 8 has a projector 8A that projects a visible laser beam as detection light onto the reflecting surface of the MEMS mirror 4, and a camera 8B equipped with an imaging element such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device) that captures the visible laser beam reflected by the MEMS mirror 4. The path of the visible laser beam from the angle sensor 8 is set so as not to interfere with the laser beam emitted from the light-projecting / light-receiving module 2. Horizontal scanning of the MEMS mirror 4 can be detected based on the position of the light spot of the visible laser beam in the image captured by the camera 8B. Note that the light projected by the projector 8A is not limited to visible light and does not have to be laser light. Furthermore, a line scanner or the like may be used instead of the camera 8B that uses the imaging element described above.

[0032] Although it is technically possible to incorporate an angle sensor as a MEMS device into the MEMS mirror 4 itself, this would require extremely high costs. The system disclosed in Patent Document 2 performs accurate beam steering control by adding a capacitance-type angle sensor as a MEMS device to a silicon semiconductor-based MEMS mirror and feeding back angle information. However, silicon semiconductor-based MEMS mirrors with a capacitance-type angle sensor as a MEMS device are not currently available on the market, and their production would require extremely high costs. Therefore, in this embodiment, the angle sensor 8 described above is provided separately, rather than as a MEMS device.

[0033] The LiDAR system 1 of this embodiment has a three-layer structure from the bottom. In the lower layer, in addition to a light-emitting / light-receiving module 2 and a fixed mirror 3, a MEMS mirror 4 for horizontal scanning is arranged. In the middle layer, a rotating dihedral mirror 5 for vertical scanning is arranged. This middle layer also has an aperture for emitting laser light into a near-distance field of view. In the upper layer, a second field of view optical system including a concave mirror 6 and a telephoto lens 7 is arranged. This upper layer also has an aperture for emitting laser light into a far-distance field of view. In this way, the components can be efficiently arranged in layers, making it easy to miniaturize the LiDAR system 1.

[0034] The LiDAR system 1 according to the embodiment includes a light projecting module 2, a first optical scanning element 4, a second optical scanning element 5, an optical deflection element 6, and a light receiving module 2. The light projecting module 2 is a silicon semiconductor-based module that projects near-infrared laser light with a wavelength of 1000 nm or less. The first optical scanning element 4 directly or indirectly receives the laser light projected from the light projecting module 2 and scans it in a first direction while reflecting it toward the second optical scanning element 5. The second optical scanning element 5 scans the laser light reflected by the first optical scanning element 4 in a second direction intersecting the first direction. The second optical scanning element 5 scans the laser light in the second direction while selectively reflecting it toward a second field of view optical system for irradiation of the first field of view or a second field of view different from the first field of view. The optical deflection element 6 is provided in the second field of view optical system and deflects the laser light reflected by the second optical scanning element 5 toward the second field of view. The light receiving module 2 receives the laser light irradiated by the second optical scanning element 5 toward the first field of view, or the reflected laser light of the laser light irradiated from the second field optical system toward the second field of view.

[0035] Because the light-projecting module 2 is a silicon semiconductor-based module that projects laser light with a wavelength of 1000 nm or less, the LiDAR system 1 can be manufactured at lower costs than a compound semiconductor-based light-projecting module that projects laser light with a wavelength of 1550 nm. Because measurements are performed using near-infrared laser light with a wavelength of 1000 nm or less, silicon semiconductor-based modules can be used for both the light-projecting module 2 and the light-receiving module 2, which also contributes to manufacturing costs at lower costs. Furthermore, while utilizing cost-effective laser light with a wavelength of 1000 nm or less, the first optical scanning element 4 and the second optical scanning element 5 can scan the laser light in both the first and second directions, enabling measurement of both the first and second fields of view. The first and second fields of view can be freely set, but, for example, as in the above embodiment, measurement of both the near-distance field of view and the far-distance field of view can be simultaneously achieved.

[0036] In particular, in the LiDAR system 1 according to the above embodiment, the first optical scanning element 4 is a silicon semiconductor-based uniaxial MEMS mirror 4. By using the MEMS mirror 4, the LiDAR system 1 can be made smaller and lighter than if a polygon mirror and a motor as its drive source were used. Furthermore, because the MEMS mirror 4 is silicon semiconductor-based rather than compound semiconductor-based, the LiDAR system 1 can be manufactured at low cost. Furthermore, because the MEMS mirror 4 as the first optical scanning element 4 only performs scanning in the first direction, a uniaxial mirror can be used, which also allows the LiDAR system 1 to be manufactured at low cost.

[0037] In particular, in the LiDAR system 1 according to the above embodiment, the first field of view is a near-distance field of view with a wide viewing angle, and the second field of view is a far-distance field of view with a narrow viewing angle. Here, the LiDAR system 1 performs measurements using near-infrared laser light with a wavelength of 1000 nm or less. However, the output of near-infrared laser light with a wavelength of 1000 nm or less cannot be increased due to factors such as its impact on the retina of living organisms, making it difficult to measure the far-distance field of view as is. Therefore, in the LiDAR system 1 according to the above embodiment, the second field of view optical system is provided with a telephoto lens 7 that transmits the laser light deflected by the optical deflection element 6, thereby enabling measurement of the far-distance field of view without increasing the output of the laser light itself. Providing the telephoto lens 7 in the second field of view optical system does not impede the ability to measure both the near and far-distance fields of view, and minimizes cost increases.

[0038] Additionally, in the LiDAR system 1 according to the above embodiment, the second optical scanning element 5 is a rotating dihedral mirror 5 that rotates in one direction around a rotation axis perpendicular to the second direction. Therefore, scanning in the second direction requires only rotating the rotating dihedral mirror 5 in one direction, allowing the LiDAR system 1 to be constructed with a simple and inexpensive configuration. Furthermore, the rotating dihedral mirror 5 can ensure a wide scan angle in the second direction, twice the scan angle of a two-axis MEMS mirror or a four-faceted polygon mirror. Furthermore, the second optical scanning element 5 also has the function of guiding the laser light reflected by the first optical scanning element 4 to the first field of view or second field of view optical system, and this function can also be achieved with a simple mechanism, namely, the rotating dihedral mirror 5. This simple mechanism also contributes to the operational stability of the LiDAR system 1.

[0039] Furthermore, the rotating dihedral mirror 5 can generate airflow inside the LiDAR system 1 through its rotation, thereby facilitating cooling of the LiDAR system 1. Here, a common method for cooling electronic devices such as the LiDAR system 1 is to increase the area of ​​the ground pattern on the electronic board to promote heat conduction and connect the ground pattern to a metal housing to promote heat dissipation. However, this method electrically connects the ground of the circuit on the electronic board to the metal housing. For example, if the LiDAR system 1 is mounted on a vehicle, there is a possibility that the LiDAR system 1 will be affected by a lightning strike via the vehicle body. By enabling cooling of the LiDAR system 1 using the rotating dihedral mirror 5, the electrical circuit of the LiDAR system 1 can be electrically isolated from the outside, thereby improving the electromagnetic compatibility (EMC) performance of the LiDAR system 1, such as lightning surge resistance.

[0040] As described above, the LiDAR system 1 according to the above embodiment can be manufactured at low cost. However, the LiDAR system unit is more expensive than a typical electronic device unit. Therefore, repair costs in the event of a breakdown due to a lightning strike or other cause are higher than those for a typical electronic device unit. Therefore, improving surge resistance to reduce or eliminate repair costs is a major advantage not only for manufacturers but also for users.

[0041] Although several embodiments have been described, modifications or variations of the embodiments can be made based on the above disclosure. All components of the above embodiments and all features described in the claims may be individually extracted and combined as long as they are not mutually inconsistent. For example, in the above embodiment, the first field of view is a near field of view, and the second field of view is a far field of view. Therefore, the second field of view optical system also includes a telephoto lens 7. However, the first field of view may be an ultra-near field of view with a wide field of view angle, and the second field of view may be a normal near field of view with a narrower field of view angle than the first field of view. Alternatively, the first field of view may be a forward field of view, and the second field of view may be a rearward field of view. In this case, the optical deflection element 6 of the second field of view optical system deflects the laser light backward.

[0042] Furthermore, this disclosure makes it possible to realize a LiDAR system that can measure two different fields of view simultaneously, using a low-cost laser light with a wavelength of 1000 nm or less. Therefore, for example, this can contribute to Goal 9 of the Sustainable Development Goals (SDGs) led by the United Nations, which is to "Build resilient infrastructure, promote inclusive and sustainable industrialization, and foster technological innovation." [Explanation of symbols]

[0043] 1. LiDAR system 2 (2A~2C) Light-emitting and light-receiving modules 3(3A~3C) Fixed mirror 4 MEMS mirror (first optical scanning element) 5 Rotating dihedral mirror (second optical scanning element) 6. Concave mirror (optical bias element: second field of view optical system) 7. Telescope Lenses (Second Field of View Optics Department)

Claims

1. 1. A LiDAR system comprising: a silicon semiconductor-based light-emitting module that emits near-infrared laser light having a wavelength of 1000 nm or less; a first optical scanning element that directly or indirectly receives the laser light projected from the light projecting module, scans the laser light in a first direction, and reflects the laser light toward a second optical scanning element; a second optical scanning element that selectively reflects the laser light reflected by the first optical scanning element to a second field of view optical system for irradiating a first field of view or a second field of view different from the first field of view while scanning the laser light reflected by the first optical scanning element in a second direction intersecting the first direction; an optical deflection element provided in the second field optical system, which deflects the laser light reflected by the second optical scanning element to the second field; A LiDAR system comprising: an optical receiving module that receives the laser light irradiated toward the first field of view by the second optical scanning element or reflected laser light of the laser light irradiated toward the second field of view from the second field of view optical system.

2. 10. The LiDAR system of claim 1, A LiDAR system, wherein the first optical scanning element is a silicon semiconductor-based one-axis MEMS mirror.

3. 3. The LiDAR system according to claim 1 or 2, the first field of view is a near field of view with a wide viewing angle; the second field of view is a long-distance field of view with a narrow field of view, The LiDAR system, wherein the second field of view optical system further includes a telephoto lens that passes the laser light deflected by the optical deflection element.

4. 3. The LiDAR system according to claim 1 or 2, A LiDAR system, wherein the second optical scanning element is a rotating dihedral mirror that is rotated in one direction about a rotation axis perpendicular to the second direction.

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