Light directing module

Abstract

The present application provides a light orientation module, which is arranged in an optical distance measuring device having linearly arranged light sources, and is used for reflecting linear light signals from the linearly arranged light sources and eccentrically incident, the light orientation module comprising: a light extinction body rotating along an axis, the light extinction body having a plurality of side portions arranged around the axis; a plurality of reflecting surfaces arranged on the side portions; a first light path modification portion arranged to correspond to the highest position light source and / or the lowest position light source in the linearly arranged light sources; and a light path interruption portion arranged between adjacent reflecting surfaces, wherein the first light path modification portion does not reflect the linear light signals from the highest position light source or the lowest position light source; and the light path interruption portion does not reflect the linear light signals from the linearly arranged light sources.

Description

Technical Field

[0001] This invention relates to an optical orientation module, and more particularly to an optical orientation module that improves optical distortion. Background Technology

[0002] LiDAR (Light Detection and Ranging) systems are optical ranging architectures that measure distances and depict three-dimensional objects by emitting a light beam and measuring its time of flight (TOF) – the time it takes for light to travel from emission to reception. This technology can accurately create three-dimensional images of the environment or objects and is widely used in vehicles; for example, LiDAR can be used in autonomous vehicles for environmental perception. Generally, to ensure that vehicles have sufficient reaction time to sudden situations at high speeds, optical ranging devices are required to observe objects at a distance of approximately 200 to 300 meters (or even further).

[0003] Figure 1 This is a schematic diagram of an optical rangefinder 100. (As shown...) Figure 1 As shown, the optical ranging device 100 includes a transmitting module 110, a detecting module 120, and a scanning module. The transmitting module 110 can be an array of light sources, such as multiple light sources 110A, 110B, 110C, and 110D arranged in an array. The detecting module 120 can be an array of detectors corresponding to the light sources, such as multiple detectors 120A, 120B, 120C, and 120D arranged in an array. The scanning module can be a rotating mirror 140 that rotates about a pivot 141, and it includes multiple reflectors, such as a first reflecting surface 1401, a second reflecting surface 1402, a third reflecting surface 1403, a fourth reflecting surface 1404, etc. Typically, each detector corresponds to a light source to form a detection channel. For example, the detection light LA1 emitted by light source 110A is collimated and shaped by the first mirror group 130, and then emitted from the optical ranging device 100 through the rotating mirror 140. The part of the light scattered by the detection light LA1 when it hits the object 2 forms the echo light RA1. After the echo light RA1 returns to the optical ranging device 100, it is filtered and shaped by the second mirror group (not shown) and then received by the detector 120A. Specifically, the optical ranging device 100 can calculate the distance between the object 2 and the optical ranging device 100 by using the flight time of the detection lights LA1, LA2, LA3, LA4 and the echo lights RA1, RA2, RA3, RA4, respectively. Figure 1 The optical rangefinder 100 utilizes the rotation of a rotating mirror 140 along a pivot 141 to scan the probe light LA ​​within the field of view (FOV), hence it is also called a scanning rangefinder. Figure 1For example, the highest-positioned probe light LA1 corresponds to the highest first reflection area 142 on the first reflecting mirror 1401, while the lowest-positioned probe light LA4 corresponds to the lowest second reflection area 143 on the first reflecting mirror 1401 (note that the first reflection area 142 and the second reflection area 143 are imaginary areas used only for illustrative purposes). The light reflected from the outermost reflection positions A and B on the first reflection area 142 by probe light LA1 will scan within an angular range on the same horizontal plane. The scanning angle can be determined by the characteristics of the first reflecting surface 1401 (e.g., the distance between reflection positions A and B, the rotation speed of the rotating mirror 140, the number of reflecting mirrors on the rotating mirror 140, etc.), and the first echo light RA1 on this horizontal plane is received by detector 120A. When the rotating mirror 140 rotates, the probe light LA1 starts to illuminate from reflection position A and gradually moves to reflection position B, thus constituting one field of view scan. Reflection positions A and C, and reflection positions B and D define the left and right scanning edges or scanning boundaries of the field of view.

[0004] However, due to the need for system miniaturization, the layout space for the aforementioned array-arranged light sources 110A, 110B, 110C, 110D and detectors 120A, 120B, 120C, 120D becomes very limited. Furthermore, the characteristics of the rotating mirror 140 (such as surface properties and angular errors) significantly affect the light. For example, when the rotating mirror 140 rotates, its effect on the probe lights LA1, LA2, LA3, and LA4 is dynamically changing. Figure 1 For example, when t0, the probe light LA1 illuminates the highest and outermost reflection position A on the left side of the first reflection area 142. As the rotating mirror 140 rotates clockwise, the illumination point of the probe light LA1 on the first reflecting surface 1401 gradually moves to the highest and outermost reflection position B on the right side of the first reflection area 142. Since the reflection positions A and B have different reflection angles for the probe light LA1, and since the probe light LA1 is not incident on the axis 141 of the rotating mirror 140 (i.e., eccentric incident as described later), the angle and distance of the probe light LA1 illuminating the reflection positions A and B are different, causing the optical characteristics of the probe light LA1 at the reflection positions A and B to differ. This can be collectively referred to as optical distortion, which in turn causes the problem of field distortion in subsequent interpretation.

[0005] For example, Figure 2 This is a schematic diagram of a field of view deformation. Figure 2 Matching Figure 1 It can be seen that the Z-axis is called the vertical direction, and the array of light sources 110A, 110B, 110C, and 110D are actually arranged along the Z-axis perpendicular to the ground. Figure 1The rotating mirror 140 shown is connected to a motor or other driving component and rotates continuously in a one-dimensional rotation on a horizontal plane (i.e., the plane formed by the X-axis and Y-axis, which is actually parallel to the ground).

[0006] When the rotating mirror 140 rotates to scan the probe light LA, for example, a 130° field of view can be generated in the horizontal direction. Theoretically, the field of view formed by the four light sources 110A, 110B, 110C, and 110D after the rotation of the first reflecting surface 1401 is a rectangular field of view FA. However, as mentioned above, when the light source is eccentrically incident on the rotating mirror 140, the rotation angle of the rotating mirror 140 and the distance between the light source and the reflecting surface of the rotating mirror 140 will cause a distortion of the field of view. Figure 2 The asymmetrical field of view (FB) shown will produce the following when light source 110A scans from reflection position A to reflection position B: Figure 2 The field of view FB1 extends from region A' to region B'. Figure 2 In the diagram, four light sources, 110A, 110B, 110C, and 110D, provide fields of view FB1, FB2, FB3, and FB4 from top to bottom, respectively. These four fields of view are stitched together to form a full field of view FB. The point cloud signal obtained by scanning the full field of view FB can be defined as a scanning frame. The full field of view FB has a horizontal field of view FOV(H) and a horizontal field of view FOV(V). The former can be simply referred to as the horizontal field of view or horizontal viewing angle, and the latter can be simply referred to as the vertical field of view or vertical viewing angle.

[0007] Figure 2 It can also be observed that fields of view FB1, FB2, FB3, and FB4 all exhibit varying degrees of distortion due to optical aberration. Taking field of view FB1 as an example, the difference in optical characteristics of the probe light LA1 at reflection positions A and B causes field of view distortion, such as different shapes and different heights on the left and right sides. Compared to the ideal rectangular field of view FA, field of view FB1 has a convex distorted area (such as the dark area A'). This is understandable. Figure 2 The dark area A' in the field of view FB1 represents the distorted scanning point or area caused by the probe light LA1 at the reflection position A, while Figure 2 In the field of view FB1, region B' corresponds to the distorted scanning point or area caused by the reflection position B of the probe light LA1. Correspondingly, compared to the ideal rectangular field of view FA, the field of view FB4 has a distorted region with a protruding portion (such as the dark region C'); understandably, Figure 2 The dark area C' in the field of view FB4 represents the distortion caused by the probe light LA4 at the reflection position C, while Figure 2 The region D' of the field of view FB4 corresponds to the scanning point or scanning area caused by the reflection position D of the probe light LA4. In other words, Figure 2 The field of view FB shown is Figure 1The field of view is formed by the rotation of the first reflecting surface 1401 through four light sources 110A, 110B, 110C, and 110D. However, due to optical distortion, the scanning field of view on the four different horizontal planes is deformed. Figure 2 The edges of the middle reflector will have more severe deformation problems than the middle of the reflector.

[0008] The aforementioned deformed field of view usually requires additional point cloud processing, which increases the computational burden on the LiDAR system or autonomous driving system and may raise concerns about driving safety (especially in autonomous driving scenarios).

[0009] Other, Figure 3 The diagram shows a top view of the rotating mirror 140. Connecting portions 144 are provided between adjacent reflecting surfaces. For example, high-reflectivity mirrors are used as the aforementioned reflecting surfaces, and the mirrors are directly spliced ​​together to form the rotating mirror 140. The connecting portions 144 between adjacent mirrors form a structure resembling a sharp angle. When the rotating mirror 140 rotates, each reflecting surface (such as the first reflecting surface 1401, the second reflecting surface 1402, the third reflecting surface 1403, and the fourth reflecting surface 1404) sequentially scans out a frame. In a typical design, the connecting portions 144 between adjacent mirrors are not specially treated; that is, they have the same or similar reflectivity as each reflecting surface. Therefore, the scanning frames obtained by each reflecting surface are connected to each other. In other words, when light shines on the connecting portions 144 between adjacent mirrors, it will also emit scanning light and form a point cloud. For example, when the rotating mirror 140 turns from the first reflecting surface 1401 to the second reflecting surface 1402, the part where the two mirrors meet (e.g., the corner where the reflecting surfaces meet) will also provide probe light to form a scanning point cloud, thus connecting the first scanning frame with the second scanning frame. That is, the connecting part 144 between the reflecting mirrors is a continuous reflecting surface, resulting in continuous scanning frames. Point cloud processing software / processing methods must be used to cut and separate each scanning frame. In addition, since the beam emitted by the transmitting module 110 is not actually a single point, but has a certain area, it is technically described as a light spot or light spot area; and the connecting part 144 between the aforementioned reflecting mirrors often has sharp corners, or irregular reflecting surfaces formed by assembly errors / tolerances. When the light spot illuminates the aforementioned sharp corners or other unexpected reflecting surfaces, stray light is easily generated. The stray light may be received by the detector, thus causing noise.

[0010] Again, please return to Figure 2 It can be seen that optical distortion also causes the field of view (FB) of each scan frame to be distorted left and right, for example... Figure 2As shown, blocks E1' and E2' are the deformed blocks of the field of view FB on the left and right sides. The left and right sides of the field of view FB of each scan frame are adjacent to the previous and next scan frames. With deformed blocks E1' and E2', it will also consume a lot of system computing resources to efficiently and accurately cut and separate each scan frame.

[0011] Therefore, the above issues need to be addressed when setting up a light-emitting device (Light Radiator) system or an autonomous driving system. Summary of the Invention

[0012] To effectively solve the above problems, this invention proposes a light-directing module, which is disposed in an optical ranging device with linearly arranged light sources. The light-directing module is used to reflect linear light signals from the linearly arranged light sources and incident off-center. The light-directing module includes: an extinction body that rotates along an axis, the extinction body having multiple sides arranged around the axis; multiple reflective surfaces disposed on the sides; a first optical path modification part disposed to correspond to the highest position light source and / or the lowest position light source in the linearly arranged light sources; and an optical path truncation part disposed between adjacent reflective surfaces, wherein the first optical path modification part does not reflect the linear light signals from the highest position light source or the lowest position light source; and the optical path truncation part does not reflect the linear light signals from the linearly arranged light sources.

[0013] Preferably, the first optical path modification portion is an upper chamfer and / or a lower chamfer of the reflective surface, the upper chamfer and / or the lower chamfer being located on a far-offset side; or the first optical path modification portion is an upper extinction region and / or a lower extinction region of the reflective surface, the upper chamfer and / or the lower chamfer being located on a far-offset side.

[0014] Preferably, the light orientation module further includes a second light path modification part, which is disposed on the near-eccentric side of the reflective surface to correspond to the first light path modification part.

[0015] Preferably, the width of the optical path cutoff portion is greater than the spot size output by the linearly arranged light source.

[0016] Preferably, the width of the optical path cutoff portion is between 1.5 and 5 times the size of the light spot output by the linearly arranged light source.

[0017] Preferably, the effective width of the first optical path modification portion and / or the second optical path modification portion is Where n is the number of pulses driving the linearly arranged light source, Pt is the time of each pulse, t is the time interval between adjacent pulses, and R is the rotational speed of the light-directing module.

[0018] Preferably, the first optical path modification portion and / or the second optical path modification portion and the optical path cutoff portion form a hollow structure to expose the matting body.

[0019] To effectively solve the above problems, this invention proposes a light-directing module, comprising: a body rotating along an axis, the body having a plurality of reflective surfaces arranged around the axis, wherein each reflective surface has a channel for linear light signal illumination, the channel being not aligned with the axis; an optical path modification section configured to correspond to the highest and / or lowest position optical signal in the linear light signal; and an optical path truncation section disposed between adjacent reflective surfaces, wherein when the light-directing module rotates and the optical path modification section is located in the channel, it does not reflect the highest or lowest position optical signal; and when the light-directing module rotates and the optical path truncation section is located in the channel, it does not reflect the linear light signal.

[0020] Preferably, the optical path modification portion is an upper chamfer and / or a lower chamfer provided on the side of the reflective surface; or the optical path modification portion is an upper extinction area and / or a lower extinction area provided on the side of the reflective surface.

[0021] Preferably, the area of ​​the optical path modification portion and the optical path cutoff portion is about 10% smaller than the area of ​​the reflective surfaces.

[0022] To effectively solve the above problems, the present invention proposes an optical ranging device, comprising: the aforementioned optical orientation module; and an array of light sources, including multiple light sources, to provide the linear optical signal.

[0023] To enable those skilled in the art to understand the purpose, features and effects of the present invention, the present invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of an optical rangefinder.

[0025] Figure 2 This is a schematic diagram of the asymmetric field of view (FOV) created by a rotating mirror;

[0026] Figure 3 The image shown is a top view of the rotating mirror;

[0027] Figure 4A This is an exploded view of the optical orientation module according to an embodiment of the present invention;

[0028] Figure 4B This is a schematic diagram of the assembly of a light-directing module according to an embodiment of the present invention;

[0029] Figure 5AThis is a schematic diagram of the reflective surface according to the first embodiment of the present invention;

[0030] Figure 5B This is a schematic diagram of a reflective surface according to a second embodiment of the present invention;

[0031] Figure 6 A schematic diagram of the structure of an optical ranging device according to an embodiment of the present invention; and

[0032] Figure 7 A schematic diagram of an optical ranging device according to another embodiment of the present invention.

[0033] Explanation of icon numbers

[0034] 1: Optical ranging device

[0035] 2: Object

[0036] 10: Shell

[0037] 20: Windows

[0038] 30: Launch Module

[0039] 31A, 31B, 31C, 31D, ... 31N: Light source

[0040] 40: Rotating Mirror

[0041] 41: Axis

[0042] 50: Detection Module

[0043] 60: First Shot Group

[0044] 70: Reflector

[0045] 80: Second Shot Group

[0046] 100: Optical ranging device

[0047] 110: Transmission Module

[0048] 110A, 110B, 110C, 110D: Light source

[0049] 120: Detection Module

[0050] 120A, 120B, 120C, 120D: Detectors

[0051] 130: First Shot Group

[0052] 140: Rotating Mirror

[0053] 141: Shaft

[0054] 142: First Reflection Zone

[0055] 143: Second Reflection Zone

[0056] 200, 200A, 200B, 700: Reflective surface

[0057] 202A: Lower left chamfer

[0058] 202B: Upper left side chamfer

[0059] 204A: Lower right chamfer

[0060] 204B: Upper right side chamfer

[0061] 300: matte body

[0062] 302: Side

[0063] 400: First Optical Path Modification Department

[0064] 500: Optical path cutoff section

[0065] 600: Second optical path modification section

[0066] 701A: Upper reflector

[0067] 701B: Lower reflector

[0068] 1401: First reflecting mirror

[0069] 1402: Second reflecting mirror

[0070] 1403: Third reflecting mirror

[0071] 1404: Fourth reflecting mirror

[0072] A, B, C, D: Reflection positions

[0073] A', B', C', D': Regions

[0074] E1', E2': Deformation blocks

[0075] FA: Rectangular field of view

[0076] FB, FB1, FB2, FB3, FB4: Field of View

[0077] FOV(H): Vertical field of view

[0078] FOV(V): Horizontal field of view

[0079] L1, L2, L3, L4: Light spots

[0080] LA, LA1, LA2, LA3, LA4: Probe beams

[0081] M: Line

[0082] RA, RA1, RA2, RA3, RA4: Echoes

[0083] X, Y, Z: Direction Detailed Implementation

[0084] The embodiments of the present invention will be described in more detail below with reference to the accompanying drawings and component symbols, so that those skilled in the art can implement them after studying this specification.

[0085] Unless otherwise specified, the term "scanning" in this article refers to a LiDAR system emitting one or more beams of light in one or more directions (e.g., horizontal and / or vertical) to scan objects within its field of view (FOV). This article primarily addresses the optical challenges encountered by scanning LiDAR systems, not scanning-based systems such as flash LiDAR, which are not included in the solutions presented here.

[0086] Unless otherwise specified, the positions referred to in this article, such as the highest position and the lowest position, refer to the general perception of high and low. For example, with the horizontal plane as the reference, the farthest point above the horizontal plane is the highest position, and the closest point above the horizontal plane is the lowest position.

[0087] Figure 4A and Figure 4B This is an exploded view and assembly diagram of the optical orientation module 40 according to an embodiment of the present invention. Figure 4A , Figure 4B As shown, an embodiment of the present invention provides a light orientation module 40 for emitting a linear light signal from a first direction to scan in a field of view (FOV) in a second direction. The light orientation module 40 includes: an extinction body 300; a plurality of reflective surfaces 200; a first light path modification part 400; and a light path truncation part 500.

[0088] Specifically, the matte body 300 rotates along axis 41. The matte body 300 has a plurality of sides 302 arranged around said axis. It is understood that the matte body 300 is a columnar body, including but not limited to triangular prisms, quadrangular prisms, etc., and the matte body 300 can be connected to a rotary motor (such as a motor) to achieve rotation along axis 41. Therefore, this embodiment has four sides 302, but the number is not limited to this, for example, 2, 3, 5, or others. Furthermore, the matte body 300 can be formed from a matte material or by applying matte paint to other materials. The matte body 300 in this document can be formed using any known technology, which will not be elaborated further. The matte body 300 of this embodiment is molded from black plastic. It is worth noting that "matte" as used herein refers to a material having low reflectivity to a specific light source, such as that described in this document. Figure 6The optical ranging device 1, wherein the emitting module 30 can emit detection light with a center wavelength of 905nm, 940nm or 1550nm, and the extinction body 300 can have low reflectivity in a wide range of wavelengths, for example, the reflectivity in the 380nm to 1600nm band can be less than or equal to 7%, 5%, 2% or 1%; or the extinction body 300 can have reflectivity less than or equal to 7%, 5%, 2% or 1% in certain specific wavelength ranges, such as 905nm±10%, 940nm±10% or 1550nm±10%.

[0089] Specifically, the reflective surface 200 is preferably disposed on each side portion 302, but is not limited thereto. The reflective surface 200 of this embodiment of the invention can have a reflectivity of 95% or 98% or higher for light sources of specific wavelengths (e.g., 905nm, 940nm, or 1550nm wavelength light sources). The material of the reflective surface 200 is not limited to glass, aluminum plates, etc., with high-reflectivity coatings (e.g., chromium or nickel films with a thickness of 500-1000nm), and is fixed to the side portion 302 by suitable methods such as bonding, welding, screwing, riveting, etc. The reflective surface 200 has a first optical path modification portion 400, corresponding to the highest / lowest position of the light source in the light source outputting the linear optical signal, to modify the obtained scanning frame, thereby eliminating or reducing the distortion area of ​​the field of view. Specifically, the first optical path modification portion 400 can be achieved by cutting a portion of each reflective surface 200 or by coating each reflective surface 200 with a matte varnish. The chamfered reflective surface 200 exposes the side portion 302 of the underlying matte body 300, preventing the chamfered portion from reflecting the probe light, thus achieving the effect of modifying the optical path. Understandably, in another embodiment, a first optical path modification portion 400 is formed on the reflective surface 200 with matte paint. The portion of the reflective surface 200 coated with matte paint will not reflect the probe light, thereby achieving the effect of modifying the optical path.

[0090] Therefore, the optical distortion caused by the difference in optical path / angle resulting from the linear optical signal illuminating the reflecting surface 200 in a direction deviating from the axis 41 can be mitigated by the first optical path modification part 400 to achieve symmetry of the field of view as much as possible. Specifically, due to the provision of the first optical path modification part 400, the reflecting surface 200 is used to improve the asymmetry of the field of view, thereby reducing optical distortion. That is, improving... Figure 2 The wider FOV protrusion shown makes the FOV with optical distortion closer to the ideal FOV, thereby reducing additional processing and further reducing the computational burden on the LiDAR system or autonomous driving system.

[0091] Figure 5A The diagram below is a schematic representation of a single reflective surface 200A according to a first embodiment of the present invention. The following description can be applied to each reflective surface 200 of the present invention. Figure 5A In the diagram, the M-line along the Z-direction represents... Figure 6Four light sources, arranged linearly from top to bottom along the Z-axis, are incident on the reflective surface 200A, corresponding to four light spots / signals L1, L2, L3, and L4. The M-line can be defined as the channel through which the four linearly arranged light signals are irradiated. The aforementioned eccentric incidence also means that the channel defined by the M-line is not aligned with the axis 41. The reflective surface 200A includes a lower left chamfer 202A and an upper left chamfer 202B. The term "chamfer" is used only to illustrate the specific embodiment of the optical path modification part and is not intended to limit the invention.

[0092] It is understandable that the lower left chamfer 202A and the upper left chamfer 202B are the aforementioned first optical path modification part 400. The following combinations... Figure 2 The drawn distorted field of view (FB) is used for explanation, corresponding to Figure 2 In the deformed region A', the upper left chamfer 202B of the reflective surface 200A exposes the underlying extinction body 300, so that the chamfered portion prevents the probe light from scanning in the FOV, thus modifying the optical path and reducing or eliminating light. Figure 2 The deformed region A'; similarly, the lower left chamfer 202A of the reflective surface 200A exposes the underlying extinction body 300, so that the chamfered portion prevents the probe light from scanning in the FOV, thus modifying the optical path and reducing or eliminating light. Figure 2 The deformation region C'. In other words, the present invention creates a first optical path modification portion 400 on the reflecting surface 200A along the arrangement direction of the linear optical signal (i.e., the Z direction as defined herein), which includes a lower left chamfer 202A and an upper left chamfer 202B corresponding to the highest light source (or the highest position optical signal L1) and the lowest light source (or the lowest position optical signal L4). More specifically, the first optical path modification portion 400 of the reflecting surface 200A is preferably located on the far-offset side of the incident linear optical signal on the reflecting surface 200A (i.e., the side where the linear optical signal is incident). Figure 5A (The left side of the drawn axis 41). It is worth noting that linear light signal incident aligned with axis 41 means that the illumination channel of the linear light signal on the reflecting surface 200A is aligned with axis 41 (i.e., non-eccentric); conversely, linear light signal eccentric incident means that the illumination channel (M line) of the linear light signal on the reflecting surface 200A is not aligned with axis 41, but is biased to one side. Figure 5A In this case, when the reflecting surface 200A rotates, the illumination path of the linear light signal on the reflecting surface 200A is biased to the right. In summary, the reflecting surface 200A of the first embodiment of the present invention has chamfered angles 202A and 202B (i.e., the first optical path modification part 400) on the side away from the eccentric incident position, corresponding to the positions of the highest and lowest light sources. Therefore, when the leftmost edge of the reflecting surface 200A rotates to the reflection path defined by the M-line, the light spot / light signal L1 of the highest position light source 31A will be absorbed (i.e., no reflected light is generated) due to the modification effect of the chamfered angle 202B, thus reducing or eliminating... Figure 2 The deformed region A'; the light spot L4 of the lowest position light source 31D will be absorbed due to the modification effect of the chamfer 202A (i.e., no reflected light is produced), thus reducing or eliminating Figure 2 The deformation region C'.

[0093] Alternatively, the same effect can be achieved by applying a matte varnish to the reflective surface 200A to form a non-reflective first optical path modification part 400.

[0094] In another embodiment, since the light from the lowest position light source 31D is mainly used to scan obstacles on the road surface that are closer to the vehicle, under close-range conditions, Figure 2 The degree of deformation in the deformation region C' is relatively small, so the reflective surface 200A does not need to be chamfered 202A, that is, only the far-offset side is retained, and the chamfer 202B corresponding to the highest light source is retained; in other words, the first optical path modification part 400 only contains one chamfer 202B.

[0095] Figure 5B This is a schematic diagram of the reflective surface 200B according to a second embodiment of the present invention. Figure 5B In the middle, the reflective surface 200B includes a right upper side chamfer 204B, a left upper side chamfer 202B, a right lower side chamfer 204A, and a left lower side chamfer 202A.

[0096] The difference between the reflective surfaces of the first and second embodiments of the present invention is that the reflective surface 200B of the second embodiment of the present invention further includes a reflective surface located on the near-eccentric side (i.e. Figure 5B The lower right chamfer 204A and the upper right chamfer 204B (right side of axis 41).

[0097] Here, the lower right chamfer 204A and the upper right chamfer 204B constitute the second optical path modification section 600, which is configured to correspond to the first optical path modification section 400. Since the optical orientation module 40 rotates at high speed, for example, above 3000 rpm, it is preferable to provide the second optical path modification section 600 corresponding to the first optical path modification section 400 near the eccentric side. This makes the rotation more balanced and easier to control the rotation speed, thereby achieving scanning precision. In one embodiment, the first optical path modification section 400 only includes the upper left chamfer 202B, and the second optical path modification section 600 also correspondingly includes only the upper right chamfer 204B.

[0098] Please return Figure 4B The optical path interruption portion 500 is disposed adjacent to adjacent reflective surfaces 200 to create a gap that does not reflect the linear optical signal. Specifically, the optical path interruption portion 500 forms a gap between adjacent reflective surfaces 200, the gap width of which is preferably greater than the diameter of the light spot; or a matte varnish is applied to the joint or connection of adjacent reflective surfaces 200, and the width of the matte varnish application is preferably greater than the diameter of the light spot.

[0099] Therefore, the optical path interruption section 500 can form a non-reflective region between adjacent reflective surfaces 200, that is, it can create a breakpoint in the scanning signal using the hardware structure. Thus, a discontinuity is naturally formed between each scanning frame. Therefore, during continuous scanning, there is no need to cut the scanning frame separately, thereby reducing additional processing and further reducing the computational burden of the LiDAR system or autonomous system. The optical path interruption section 500 can also eliminate or reduce Figure 2 The deformable blocks E1' and E2' shown can also reduce the computational burden of the LiDAR system or the autonomous driving system.

[0100] Furthermore, the gap structure or extinction layer structure of the optical path cutoff section 500 can eliminate the sharp corners or unintended reflection structures of the assembly, that is, it can reduce or eliminate the reflection caused by the light spot in the above-mentioned area, thus reducing stray light.

[0101] In this embodiment, the effective width of the optical path cutoff portion 500 is approximately greater than the width of the light source passing through the first mirror group 60 (in conjunction with...). Figure 6 The adjusted spot size is used to create a break in the optical signal. Preferably, the effective width of the optical path cutoff portion 500 is approximately 1.5 to 5 times the aforementioned spot size. A 1.5 times width optical path cutoff portion 500 ensures that the light emitted by the light source is cut off as much as possible. However, the optical path cutoff portion 500 should not be too large, because the width of the reflective surface is related to the scannable horizontal field of view. The larger the reflective surface width, the larger the horizontal field of view can theoretically be obtained, and the larger the range of obstacles that can be detected. Therefore, the present invention preferably uses 5 times the spot size as the width of the optical path cutoff portion 500. In one embodiment, the dimensions of the optical path cutoff portion 500 in the Z-axis direction are approximately the same.

[0102] In this embodiment, the width of the optical path modification section 400 is related to the duration of light emission from the light source. For example, the light source is driven to emit light by a detection pulse signal emitted by the controller; each emission is called a scan. Figure 1 The first detection pulse signal is generated when the probe light LA1 illuminates point A. Then, the second, third, fourth…Nth probe light is emitted according to the excitation sequence of the detection pulses. The Nth probe light will illuminate… Figure 1 Position B in the diagram. Assuming a single detection process includes 400 scans (i.e., 400 pulse signals, N=400), and the pulse time interval is t, the total time to complete one detection is... Where Pt is the duration of each output pulse, typically on the order of hundreds of picoseconds (ps), and Therefore, assuming that the first 5 probe pulse signals in the timing sequence are to prevent the generation of a scanning signal, the effective width of the optical path modification section 400 is then... Where R is the rotational speed of the light-directing module 40, the calculated effective width can be either length (i.e., the rotational speed R is a linear velocity) or angle (the rotational speed R is an angular velocity), and the two can be interchanged through mathematical operations, which will not be elaborated on here. It is worth noting that the effective width refers to the actual width that affects the light (i.e., the width without reflection). This invention does not limit the specific structure or shape of the light path modification part 400, and the required effective width can be achieved by coordinating the processing of the reflector or the parameters of the matte varnish coating. The size and shape of the second light path modification part 600 are preferably substantially the same as those of the first light path modification part 400.

[0103] In summary, the effective width of the optical path truncating portion 500 is between 1.5 and 5 times the spot size, preferably 1.5 to 3 times. The effective width of the optical path modifying portion 400 can be expressed by the following formula: Where Pt is the duration of each output pulse, t is the interval between adjacent pulses, R is the rotational speed of the optical orientation module 40, and n is the number of pulses that do not generate a scanning signal.

[0104] In this embodiment, as Figure 4B As shown, the optical path modification parts 400 and 600 form chamfers by utilizing the highest and lowest positions of the side edges of the reflective surfaces, while the optical path cutoff part 500 forms a gap structure between adjacent reflective surfaces. Due to the manufacturing process of the reflectors, the two are structurally connected, forming a dumbbell-shaped (wide on both sides and narrow in the middle) hollow structure between adjacent reflective surfaces. The hollow structure means that the light emitted by the light source will not be reflected here. More specifically, the hollow structure exposes the extinction body 300 inside the reflective surface, so that the light emitted by the light source is absorbed or dissipated, and only a very small percentage of the light is reflected. This can be achieved, for example, by the low reflectivity of the extinction body 300. In one variant embodiment, the first optical path modification portion 400 includes only the upper left chamfer 202B, and the second optical path modification portion 600 correspondingly includes only the upper right chamfer 204B. The upper left chamfer 202B and the upper right chamfer 204B are connected to the optical path cutoff portion 500 to form a Y-shape, such as a hollow structure with a wider head on one side and a narrower body in the middle, to expose the light-absorbing body 300 within the reflective surface. In another variant embodiment, the optical path modification portions 400 and 600 are not connected to the optical path cutoff portion 500.

[0105] In a variation embodiment, the effective width of the optical path modification portions 400 and 600 is less than or equal to the effective width of the optical path truncation portion 500.

[0106] Since the optical path modification portions 400 and 600 and the optical path cutoff portion 500 refer to areas where reflection does not occur, for the optical orientation module 40, in order to maintain effective scanning, it is recommended to have sufficient reflective area. That is, in this embodiment, the area ratio occupied by the optical path modification portion 400 and the optical path cutoff portion 500 should be less than 10%, 5%, 3%, and 1% of the total reflective area, respectively, but cannot be zero. Figure 4A , Figure 4B For example, first measure the area of ​​the four reflective surfaces, then measure the area of ​​the assembled optical path modification parts 400, 600 and the optical path cutoff part 500. The ratio between the two can then be calculated. After calculation, Figure 4A , Figure 4B The non-reflective area of ​​the illustrated embodiment is approximately 9% of the reflective area.

[0107] Figure 6 A schematic diagram of the optical ranging device 1 according to an embodiment of the present invention. Figure 6 As shown, this embodiment of the invention provides an optical ranging device 1, including a housing 10, a window 20, a transmitting module 30, a light-directing module 40, a detection module 50, a first mirror group 60, a reflecting mirror 70, and a second mirror group 80. The housing 10 and the window 20 are assembled to form a space accommodating the aforementioned modules. It is worth noting that... Figure 6 The position of the emission module 30 at the offset incident point of the light-directing module 40 is different from that in the previous embodiment. Therefore, the positions of the first and second optical path modification parts 400 and 600 are also adjusted accordingly. Figures 4A-5B A schematic diagram.

[0108] The optical ranging device 1 of this embodiment can be, for example, a forward-facing lidar, as shown in the figure. The window 20 faces forward (e.g., the direction of vehicle travel), and the detection light LA ​​is guided outward from the window 20 for scanning and detection. The transmitting module 30 includes an array of light sources, such as multiple light sources arranged in an array. An exemplary light source array may be... Wait, to simplify the attached diagram, Figure 6 Only four light sources, 31A, 31B, 31C, and 31D, are drawn. In this embodiment, the array arrangement means that light sources 31A, 31B, 31C, and 31D are arranged substantially along the direction Z (also known as the vertical direction or Z-axis) perpendicular to the ground. That is, the number "1" in the aforementioned array formula represents that the light sources are set in a row in the direction Z to become linear light sources. Figure 6 When light sources 31A, 31B, 31C, and 31D emit a single linear light signal, the object can be scanned in the Z direction. It is worth noting that light sources 31A, 31B, 31C, and 31D do not need to be perfectly aligned; they can be slightly offset, as long as they can be considered as linear light signals in signal processing, they fall within the scope of this invention.

[0109] The detection module 50 includes an array of detectors (not shown in the figure), which are configured in a manner corresponding to an array of light sources, such as the arrangement of the detectors, the adjacent distance, the sensing angle, etc. The configuration of the detection module 50 in this paper can be deployed using any known technology, and will not be described in detail here.

[0110] like Figure 6 As shown, light sources 31A, 31B, 31C, and 31D output linear light signals. After adjustment (e.g., shaping or collimation) by the first mirror group 60, the signals are then emitted through the window 20 towards the outside of the optical ranging device 1 via the light-directing module 40, forming the probe light LA. In this embodiment, the light-directing module 40, which has three reflective surfaces, is connected to a driving component such as a motor and rotates continuously. Figure 6 The image is drawn as a one-dimensional rotation on a horizontal plane (i.e., the plane formed by the X and Y axes, which is essentially parallel to the ground). Figure 6 The mid-light orientation module 40 also schematically rotates clockwise along axis 41 as indicated by the arrow, thereby enabling the probe light LA ​​to scan the XY plane to detect objects in the horizontal field of view (relative to the vertical field of view). It is understood that... Figure 6 The LiDAR system on display uses a linear array of light emitting modules 30 arranged in the column (Z-axis) to achieve vertical field-of-view scanning, and then uses a one-dimensional rotation of the light orientation module 40 in the lateral direction to achieve horizontal field-of-view scanning, so as to achieve scanning of the space in front of the vehicle. By scanning and detecting each time the probe light LA ​​scans in the vertical and horizontal directions, a detection result can be obtained, such as a point cloud map of one frame. This point cloud map can cover the total field of view of a horizontal field of view and a vertical field of view. The present invention mainly focuses on the optical distortion of the vertical field of view.

[0111] It should be understood here that the chamfer 202B of the first optical path modification section 400 is configured to correspond to the highest position light source among the light sources 31A, 31B, 31C, and 31D that output the linear optical signal, for example, light source 31A. The highest position light source is used to generate the uppermost part of the vertical field of view (see reference). Figure 2 The field of view FB1), that is, the position of the chamfer 202B is on the far-offset side of the reflecting surface (i.e., the ...). Figure 6 (The right side of each reflector) and located at the highest position on the right side of that reflector; preferably, Figure 6 The position of the chamfer 202A of the first optical path modification part 400 is also drawn to correspond to the lowest position light source, that is, light source 31D. The lowest position light source is used to generate the lowermost part of the vertical field of view (see reference). Figure 2 The field of view FB4), that is, the position of the chamfer 202A is on the far-offset side of the reflecting surface (i.e., Figure 6 (The right side of each reflector) and located at the lowest position on the right side of that reflector. Preferably, Figure 6 Draw a second optical path modification part 600 corresponding to the first optical path modification part 400, such as chamfers 204A and 204B. The position of chamfer 204B is on the near-eccentric side of the reflecting surface (i.e., Figure 6 The left side of each reflector) and located at the highest point on the left side of that reflector, with the chamfer 204A positioned on the near-eccentric side of the reflecting surface (i.e., Figure 6 (The left side of each of the reflectors) and located at the lowest position on the left side of that reflector.

[0112] exist Figure 6 In the process, the probe light LA ​​is reflected and diffused by an object (not shown) to form an echo light RA. The echo light RA enters the optical ranging device 1 through the window 20, and after passing through the light orientation module 40, the reflector 70, and the second mirror group 80 (e.g., shaping or focusing), it is received by the probe module 50.

[0113] In some embodiments, the number of light sources 31A, 31B, 31C, 31D and detectors forming the detection channel is not limited. Preferably, light sources 31A, 31B, 31C, 31D and their corresponding number of detectors can form a detection channel. When light sources and detectors belonging to the same detection channel are activated and operated respectively, the detection channel is in operation, thereby enabling the detection of objects.

[0114] In some embodiments, the emitting module 30 can be a vertical cavity surface emitting laser (VCSEL) or an edge emitting laser (EEL). The laser source is driven to emit probe light LA ​​by applying a driving current to the emitting module 30. In this embodiment, a VCSEL is used, and after adjustment by the first mirror group 60, the light spot diameter is approximately 250 μm; in another embodiment, the spot diameter can be less than 100 μm or less than 50 μm. The optical path cutoff portion 500 is preferably larger than the aforementioned spot size; or, the effective width of the optical path cutoff portion 500 is between 1.5 and 3 times, 1.5 and 5 times, 1.5 and 10 times, or 1.2 and 1.5 times the aforementioned spot size. Alternatively, the effective width of the optical path cutoff section 500 is approximately equal to the aforementioned spot size, because the energy distribution of the spot will be concentrated in the center of the spot, with only a small amount of energy remaining around it. Even if this low-energy light shines on an obstacle and forms an echo, it will not be received by the detection module 50 to form an optical signal due to energy attenuation.

[0115] In some embodiments, the detection module 50 may be an avalanche photodiode (APD) or a silicon photomultiplier (SiPM). The detection module 50 is activated to detect the echo light RA by applying a bias voltage (Vbias) to the detector of the avalanche photodiode or silicon photomultiplier.

[0116] Figure 7 A schematic diagram of the structure of an optical ranging device 1 according to another embodiment of the present invention. (See attached diagram.) Figure 7 As shown, this embodiment of the invention provides an optical ranging device 1, which mainly includes a transmitting module 30, an optical orientation module 40, and a detection module 50. It is worth noting that... Figure 7 The optical rangefinder 1 shown may also include modules or components not depicted. Figure 6 The differences include at least that the light-directing module 40 is divided into upper and lower sections due to different optical paths. Taking the reflector 700 as an example, the linearly arranged light sources 31A, 31B, ... 31N of the emitting module 30 output probe light LA, which illuminates the lower reflector 701B of the reflector 700 and is scanned by the rotation of the light-directing module 40; when an obstacle forms an echo signal RA, the echo signal RA will illuminate the detector module 50 through the upper reflector 701A of the reflector 700.

[0117] In this embodiment, the light-directing module 40 is a one-piece metal reflector mount. Its sides can be directly used as reflective surfaces, or additional coatings can be applied to improve reflectivity. Each reflective surface can be coated with an matting material to form an matting area, thereby creating the aforementioned light path modification portions 400, 600, or light path cutoff portions 500. Other related descriptions can be found above and will not be repeated here. It is worth noting that... Figure 7 The extinction areas (i.e., the optical path modification parts 400 and 600) are drawn with sharp corners to correspond to the chamfered corners of the mirrors in the aforementioned embodiments, in order to facilitate understanding of the present invention. For example, Figure 7 The pointed matte area achieves the same optical function as the chamfered cutout in the aforementioned embodiment. The matte area in this embodiment can be coated into various suitable shapes, as long as its effective width meets the aforementioned requirements.

[0118] It should be understood that the optical ranging device 1 of this invention can be installed in any vehicle as defined by the Society of Automotive Engineers (SAE) as a non-automated vehicle, partially automated (driver-assisted) vehicle, conditionally automated vehicle, highly automated vehicle, or driverless (fully automated) vehicle. For example, a partially automated vehicle can perform certain driving functions without a human driver operating the steering wheel / pedal, such as lane keeping and / or lane changing, automatic emergency braking, etc.; similarly, a driverless vehicle can operate autonomously in any situation.

[0119] It should be noted that the first mirror group 60, the reflecting mirror 70, and the second mirror group 80 in this embodiment of the invention can all be selected from known optical devices, which will not be described in detail here. Furthermore, suitable optical mirror groups can be added to the optical path as needed, and are not limited to this embodiment. Figure 6 , Figure 7 The optical path shown is merely an example and is not actually limited to the optical path structure of the optical ranging device 1 of the present invention.

[0120] This invention is not limited to the above embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made to this invention without departing from the spirit or scope of the invention.

[0121] Therefore, this invention is intended to cover any modifications and variations made to this invention or that fall within the scope of the appended claims and their equivalents.

Claims

1. A light-directing module disposed in an optical ranging device having linearly arranged light sources, the light-directing module being used to reflect linear light signals incident off-center from the linearly arranged light sources, the light-directing module comprising: The matte body rotates along an axis, and the matte body has a plurality of sides arranged around the axis; Multiple reflective surfaces are disposed on the side portion; A first optical path modification section is provided to correspond to the highest position light source and / or the lowest position light source in the linearly arranged light sources; as well as The optical path interruption section is located between adjacent reflecting surfaces. The first optical path modification section does not reflect the linear optical signal from the highest position light source or the lowest position light source; the optical path truncation section does not reflect the linear optical signal from the linearly arranged light sources.

2. The optical orientation module according to claim 1, wherein, The first optical path modification part is an upper chamfer and / or a lower chamfer of the reflective surface, wherein the upper chamfer and / or the lower chamfer is located on the far-offset side; or the first optical path modification part is an upper extinction region and / or a lower extinction region of the reflective surface, wherein the upper chamfer and / or the lower chamfer is located on the far-offset side.

3. The optical orientation module according to claim 1, further comprising: The second optical path modification part is disposed on the near-eccentric side of the reflecting surface to correspond to the first optical path modification part.

4. The optical orientation module according to claim 1, wherein, The width of the optical path cutoff section is greater than the spot size output by the linearly arranged light source.

5. The optical orientation module according to claim 1, wherein, The width of the optical path cutoff portion is between 1.5 and 5 times the size of the light spot output by the linearly arranged light source.

6. The optical orientation module according to claim 3, wherein, The effective width of the first optical path modification portion and / or the second optical path modification portion is Wherein, n is the number of pulses driving the linearly arranged light source, Pt is the time of each pulse, t is the time interval between adjacent pulses, and R is the rotational speed of the light orientation module. The first optical path modification part and / or the second optical path modification part and the optical path truncation part constitute a hollow structure to expose the extinction body.

7. A light-directing module, comprising: A body that rotates along an axis, the body having a plurality of reflective surfaces arranged around the axis, wherein each reflective surface has a channel for linear light signal illumination, the channel being not aligned with the axis; An optical path modification section is provided to correspond to the highest position optical signal and / or the lowest position optical signal in the linear optical signal; as well as The optical path interruption section is located between adjacent reflecting surfaces. Specifically, when the optical orientation module rotates and the optical path modification part is located in the channel, it does not reflect the optical signal from the highest position or the lowest position; when the optical orientation module rotates and the optical path cutoff part is located in the channel, it does not reflect the linear optical signal.

8. The optical orientation module according to claim 7, wherein, The optical path modification part is an upper chamfer and / or a lower chamfer provided on the side of the reflective surface; or the optical path modification part is an upper extinction area and / or a lower extinction area provided on the side of the reflective surface.

9. The optical orientation module according to claim 7, wherein, The area of ​​the optical path modification portion and the optical path cutoff portion is approximately 10% smaller than the area of ​​the reflective surfaces.

10. An optical ranging device, comprising: The optical orientation module as described in claim 1 or 7; An array of light sources, comprising multiple light sources, to provide the linear optical signal.

Images