Spectroscopic device and laser radar

Abstract

The invention provides a light splitting device and a laser radar, the light splitting device comprises a spectroscope with a reflective surface and a backlight surface, the spectroscope is also provided with a first side surface and a plurality of second side surfaces which are located at the edges of the reflective surface and the backlight surface, and the first side surface is connected with one side edge, close to a transmitting device, of the reflective surface; the plurality of second side surfaces are connected with other side edges of the reflective surface; the first side surface is obliquely arranged relative to the reflective surface, and the first side surface can avoid a light emitting path of the emitting device, so that emergent light is prevented from entering the spectroscope from the first side surface; the plurality of second side surfaces are arranged obliquely or vertically relative to the reflective surface, and the second side surfaces can avoid the echo path, so that the echo light is prevented from entering the spectroscope from the second side surfaces. In this way, stray light deviating from an expected path due to light path deflection after light rays are refracted by the spectroscope can be avoided, and therefore the accuracy of a detection result is improved.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and specifically, to a beam splitting device and a lidar. Background Art

[0002] A lidar is a device that measures parameters such as the distance and speed of a target object by sending laser light to the surface of the object and then measuring the arrival time of the reflected light beam, etc. It is widely used in scenarios such as autonomous driving. Most common lidar systems are rotating mirror optical path systems. Specifically, a rotating mirror optical path system usually uses a beam splitter to reflect the light emitted by a laser source to a rotating mirror device, and uses multiple reflecting mirrors on the surface of the rotating mirror device to emit the laser in a specified direction; when the emitted laser encounters the surface of the target object, it will be reflected back to the lidar, that is, the echo light is received. The rotating mirror device is also used to reflect the received echo light so that it shoots towards the receiving device, thereby analyzing the echo light and calculating parameters such as the distance and speed relative to the target object.

[0003] However, since the light emitted by the laser source and the echo light received by the lidar cannot be emitted and incident completely along the ideal preset direction, the echo light reaching the receiving device also cannot be incident completely along the ideal preset direction. There is a large amount of stray light deviating from the preset echo direction incident on the receiving device, which aggravates the blooming phenomenon. This will cause a large amount of noise in the signal received by the receiving device, and further lead to serious distortion of the detection result. Summary of the Invention

[0004] The present invention aims to at least solve the technical problem that the receiving device of the existing rotating mirror lidar receives a large amount of stray light, and provides a beam splitting device and a lidar.

[0005] To achieve the purpose of the present invention, a beam splitting device is provided, which includes: a beam splitter;

[0006] The beam splitter has an opposite reflecting surface and a backlight surface. The reflecting surface is arranged facing the rotating mirror device and the emitting device of the lidar, and is used to reflect the first emitted light along the first light emitting direction emitted by the emitting device to obtain the second emitted light along the second light emitting direction; the backlight surface is arranged facing the receiving device of the lidar;

[0007] The beam splitter also has a first side surface and a plurality of second side surfaces located at the edges of the reflecting surface and the backlight surface, and the first side surface is connected to one side edge of the reflecting surface close to the emitting device, and the plurality of second side surfaces are connected to the remaining side edges of the reflecting surface;

[0008] The first side surface is inclined with respect to the reflective surface, and the first side surface does not block the first emitted light; a plurality of the second side surfaces are inclined or perpendicular to the reflective surface, and the second side surfaces do not block the return light.

[0009] Optionally, a first included angle is formed between the first side surface and the reflective surface, and the first included angle satisfies that in a plane perpendicular to the first light-emitting direction, the orthographic projection of the reflective surface completely covers the orthographic projection of the first side surface;

[0010] A second included angle is formed between each of the plurality of second side surfaces and the reflective surface, and the second included angle satisfies that in a plane perpendicular to the preset return light direction, the orthographic projection of the reflective surface completely covers the orthographic projection of the second side surface.

[0011] Optionally, the beam splitting device further includes a filter and a fixing block;

[0012] One end of the fixing block is fixedly connected to the filter, and the other end of the fixing block is used for being fixedly connected to the backlight surface;

[0013] The filter allows the return light to pass through, so that the return light is directed to the receiving device.

[0014] Optionally, the beam splitting device further includes a light-shielding component; the light-shielding component includes a plurality of light-shielding sheets arranged on the periphery of the beam splitter; each light-shielding sheet is arranged parallel to the preset return light direction to block the return light deviating from the preset return light direction.

[0015] Optionally, the plurality of light-shielding sheets are divided into a first light-shielding sheet group and a second light-shielding sheet group; wherein,

[0016] The light-shielding sheets in the first light-shielding sheet group are arranged on the side of the beam splitter close to the transmitting device; the light-shielding sheets in the first light-shielding sheet group are further used to block the first emitted light deviating from the first light-emitting direction;

[0017] The light-shielding sheets in the second light-shielding sheet group are arranged on other sides of the beam splitter.

[0018] Optionally, the light-shielding sheets in the first light-shielding sheet group are arranged perpendicular to the first light-emitting direction;

[0019] The light-shielding sheets in the first light-shielding sheet group have a hollow portion and a first light-shielding portion; the hollow portion faces the reflective surface and is used for allowing the emitted light to pass through; the first light-shielding portion is arranged around the hollow portion and is used for blocking a part of the first emitted light deviating from the first light-emitting direction.

[0020] Optionally, there are multiple light-shielding plates in the second light-shielding plate group, which are arranged on the side of the beam splitter closer to the transceiver port of the lidar, are spaced apart along a direction perpendicular to the preset echo direction, and the length of the light-shielding plate farther from the beam splitter in the preset echo direction is smaller.

[0021] Optionally, there is a light-shielding plate in the second light-shielding plate group that is arranged between the first light-shielding plate group and the beam splitter, and this light-shielding plate is cooperatively connected with the first side surface to block the light directed to the backlight side of the beam splitter.

[0022] Optionally, all the light-shielding plates are made of light-absorbing materials.

[0023] Optionally, the angular ranges of the first included angle and the second included angle are both 10° to 60°.

[0024] As another technical solution, the present invention further provides a lidar, which includes a rotating mirror device, a transmitting device, a receiving device, and the beam splitting device as described above; wherein,

[0025] The light exit of the transmitting device is arranged facing the beam splitting device, and the transmitting device can emit a first outgoing light along a first light exit direction; the beam splitting device is used to reflect the first outgoing light into a second outgoing light along a second light exit direction and can allow the echo light to pass through;

[0026] The rotating mirror device is used to reflect the second outgoing light to the surface of an external object and is also used to reflect the echo light incident from the external environment towards the beam splitting device;

[0027] The receiving device is used to receive the echo light.

[0028] Optionally, the receiving device includes a receiver, a receiving lens group, and a reflecting mirror; wherein, the receiver is used to receive the echo light;

[0029] The receiving lens group is arranged on the side of the beam splitter away from the rotating mirror device, and the optical axis of the receiving lens group is parallel to the preset echo direction;

[0030] The reflecting mirror is used to reflect the light passing through the receiving lens group to the receiving port of the receiver.

[0031] The present invention has the following beneficial effects:

[0032] The beam splitting device provided by the present invention includes a beam splitter for splitting a laser signal. The beam splitter has a reflective surface, a backlight surface, and a first side surface and a plurality of second side surfaces located at the edges of the reflective surface and the backlight surface. Among them, the first side surface is connected to the side of the reflective surface close to the emitting device, and the first side surface is inclined with respect to the reflective surface, and the first side surface portion does not block the first emitted light, that is, it can avoid the light path of the emitting device, so as to prevent the first emitted light from entering the beam splitter from the first side surface; the plurality of second side surfaces are connected to the remaining sides of the reflective surface, and the second side surface is inclined or perpendicular to the reflective surface, and the second side surface portion does not block the return light, that is, it can avoid the return light path, so as to prevent the return light from entering the beam splitter from the second side surface. In this way, by preventing the emitted light and the return light from entering the beam splitter from the side surface, it is possible to avoid the light path deflection of the light after passing through the beam splitter and form stray light deviating from the expected path, thereby reducing the stray light in the return light received by the receiving device, reducing the noise in the received signal, and further improving the accuracy of the detection result. Description of the Drawings

[0033] Figure 1 Schematic structural diagram of the beam splitting device and the lidar provided by the embodiment of the present invention;

[0034] Figure 2A Rear view of the beam splitter provided by the embodiment of the present invention;

[0035] Figure 2B For Figure 2A Cross-sectional view along the straight line XX';

[0036] Figure 2C For Figure 2A Cross-sectional view along the straight line YY';

[0037] Figure 3A Schematic diagram of the beam splitter and its light path provided by the embodiment of the present invention;

[0038] Figure 3B Schematic diagram of a straight-edge beam splitter and its light path in the related art;

[0039] Figure 4 Schematic diagram of a beam splitting device and its light path provided by this embodiment;

[0040] Figure 5 Schematic diagram of another beam splitting device and its light path provided by the embodiment of the present invention;

[0041] Figure 6 Schematic structural diagram of the first light shielding sheet provided by the embodiment of the present invention;

[0042] Figure 7 Schematic structural diagram of a plurality of second light shielding sheets provided by the embodiment of the present invention;

[0043] Figure 8 This is a schematic structural diagram of the third light-shielding sheet provided by the embodiments of the present invention. Detailed implementation manners

[0044] Next, the technical solutions in some embodiments of the present disclosure will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present disclosure.

[0045] Unless otherwise required by the context, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular form "comprises" and the present participle form "comprising", are interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example", or "some examples", etc., are intended to indicate that the specific features, structures, materials, or characteristics related to the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms are not necessarily referring to the same embodiment or example. In addition, the specific features, structures, materials, or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0046] Hereinafter, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present disclosure, unless otherwise specified, the meaning of "a plurality" is two or more.

[0047] "At least one of A, B, and C" has the same meaning as "at least one of A, B, or C", and both include the following combinations of A, B, and C: only A, only B, only C, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B, and C.

[0048] "A and / or B" includes the following three combinations: only A, only B, and the combination of A and B.

[0049] As used herein, "parallel", "perpendicular", and "equal" include the stated cases as well as cases similar to the stated cases, where the range of such similar cases is within an acceptable deviation range, and the acceptable deviation range is determined by one of ordinary skill in the art considering the measurements being discussed and the errors associated with the measurements of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, where the acceptable deviation range for approximate parallelism can be, for example, within a deviation of 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, where the acceptable deviation range for approximate perpendicularity can also be, for example, within a deviation of 5°. "Equal" includes absolute equality and approximate equality, where the acceptable deviation range for approximate equality can be, for example, that the difference between the two equal values is less than or equal to 5% of either one of them.

[0050] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the dimensions of some components are adjusted for clarity. Accordingly, variations in the shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Thus, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but include shape deviations caused by, for example, manufacturing. Accordingly, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shape of the regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0051] Please refer to Figure 1 , this embodiment provides a beam splitting device applied to a lidar, which includes: a beam splitter 1.

[0052] As Figures 2A - 2C shown, the beam splitter 1 has opposite reflective surfaces 11 and backlight surfaces 12; wherein, the reflective surface 11 is arranged facing the rotary mirror device 5 and the transmitting device 6 of the lidar, and is used for reflecting the first emitted light along the first light emitting direction a1 emitted by the transmitting device 6, and obtaining the second emitted light along the second light emitting direction a2; the backlight surface 12 is arranged facing the receiving device 7 of the lidar. Moreover, the rotary mirror device 5 of the lidar is used for reflecting the emitted light along the second light emitting direction a2 to the transceiver port of the lidar, so that the emitted light reaches the surface of an external object; and after the emitted light is reflected by the surface of the external object, an echo light is formed and enters the lidar through the transceiver port of the lidar; the rotary mirror device 5 of the lidar is further used for reflecting the echo light to the receiving device 7 on the backlight side of the beam splitter 1, so that the receiving device 7 can receive the echo light and perform processing and analysis on the echo light, thereby obtaining parameters such as the distance and speed of the target object. Since the reflective surface 11 has a reflective function, the echo light does not pass through the beam splitter 1, but is directed to the receiving device 7 through the area surrounding the beam splitter 1.

[0053] Exemplarily, the beam splitter 1 includes, for example, a glass substrate and a reflective film deposited on the surface of the glass substrate. Among them, the reflective film is, for example, a dielectric film or a metal film, and the reflective film is used to reflect light.

[0054] As Figure 2B and 2C shown, the beam splitter 1 also has a first side surface 13 and a plurality of second side surfaces 14 located at the edges of the reflective surface 11 and the backlight surface 12. Among them, the first side surface 13 is connected to one side of the reflective surface 11 close to the transmitting device 6, and the plurality of second side surfaces 14 are connected to the remaining sides of the reflective surface 11. Moreover, the first side surface 13 is inclined with respect to the reflective surface 11, and the first side surface does not block the first outgoing light, so as to avoid the light path of the transmitting device 6, thereby preventing the first outgoing light from entering the beam splitter 1 from the first side surface 13; specifically, as Figure 3A shown, the first side surface 13 can be arranged parallel to the first outgoing light direction a1; or, the first side surface 13 can also be inclined towards the reflective surface 11 with respect to the first outgoing light direction a1 (that is, inclined in the direction away from the light path of the transmitting device 6). The plurality of second side surfaces 14 are inclined or perpendicular to the reflective surface 11, and the second side surfaces 14 do not block the return light along the preset echo direction b, so as to avoid the echo path, thereby preventing the return light from entering the beam splitter 1 from the second side surface 14; specifically, the second side surface 14 can be parallel to the preset echo direction b; or, the second side surface 14 can also be inclined towards the reflective surface 11 with respect to the preset echo direction b (that is, inclined in the direction away from the echo path of the return light).

[0055] It should be noted that the above preset echo direction b corresponds to the preset receiving direction of the receiving device 7. The return light incident in this direction is applicable to the processing algorithm of the receiving device 7 for the return light, while the return light in a non-preset receiving direction will interfere with the processing of the return light by the receiving device 7, that is, form noise points.

[0056] Taking Figure 3B as an example, it shows a straight-edge beam splitter 1 in the related art. This straight-edge beam splitter also has a reflective surface 11, a backlight surface 12 and a plurality of side surfaces; but different from the beam splitter 1 provided in this embodiment, as Figure 3B shown, the plurality of side surfaces of this straight-edge beam splitter 1 are all perpendicular to the reflective surface 11. Therefore, the side surfaces of this straight-edge beam splitter 1 will block the light path of the transmitting device 6 and the echo path of the return light, which is equivalent to setting a prismatic lens on the light path and the echo path, which will cause the outgoing light to deflect towards the receiving device 7, and further cause the outgoing light to directly shoot towards the receiving device 7 before reaching the reflective surface of the beam splitter, and further cause crosstalk between the received and emitted light rays; moreover, it will also cause the return light to deviate from the preset echo direction b, forming stray light, and further cause an increase in noise points in the received signal, resulting in serious distortion of the detection result.

[0057] Compared with the straight-edge beam splitter in the above related art, as Figure 3A shown, the first side surface 13 and the second side surface 14 of the beam splitter 1 provided in this embodiment can avoid the light output path and the echo path. Therefore, neither the outgoing light nor the echo light of the beam splitter 1 in this embodiment passes through the side of the beam splitter 1, thereby avoiding crosstalk between the received and transmitted light rays and reducing the stray light received by the receiving device 7, and further improving the accuracy of the detection result.

[0058] It is easy to understand that, in order to describe the relationship between the beam splitter 1 and the light path, only one of the outgoing lights and one of the echo lights are shown in the drawings. In the actual laser signal transceiver process, both the outgoing light and the echo light include countless light rays. Moreover, Figure 3A and 3B shows a situation where a preset echo direction b is parallel to the second light output direction a2. However, in fact, the preset echo direction is not limited to this direction. Moreover, the preset echo direction can also be a vector range, rather than a single vector. Exemplarily, the second light output direction a2 is perpendicular to the first light output direction a1, and correspondingly, the light-emitting surface of the beam splitter 1 is inclined at an angle of 45° with respect to the first light output direction a1.

[0059] In some specific embodiments, a first included angle θ1 is formed between the first side surface 13 and the reflecting surface, and the first included angle θ1 satisfies that in a plane perpendicular to the first light output direction a1, the orthographic projection of the reflecting surface 11 completely covers the orthographic projection of the first side surface 13; for example, the first included angle θ1 can be less than or equal to the included angle between the first side surface 13 and the first light output direction. A second included angle θ2 is formed between each of the plurality of second side surfaces 14 and the reflecting surface 11, and the second included angle θ2 satisfies that in a plane perpendicular to the preset echo direction b, the orthographic projection of the reflecting surface 11 completely covers the orthographic projection of the second side surface 14; for example, the second included angle θ2 can be less than or equal to the included angle between the second side surface 14 and the preset echo direction b.

[0060] In some preferred embodiments, the angle range of the above first included angle θ1 is 10° to 60°; within this angle range, it can be ensured that the first side surface 13 can effectively avoid the first outgoing light. The angle range of the above second included angle θ2 is 10° to 60°. Within this angle range, it can be ensured that the second side surface 14 can effectively avoid the echo light.

[0061] In some embodiments, the beam splitting device further includes a filter 2 and a fixing block 3. One end of the fixing block 3 is fixedly connected to the filter 2, and the other end of the fixing block 3 is used for fixedly connecting to the backlight surface 12 of the beam splitter 1 to mount the beam splitter 1 on the filter 2. Moreover, this mounting structure is simple and the manufacturing process is of low difficulty. The filter 2 can allow the return light to pass through, so that the return light is directed towards the receiving device for the receiving device 7 to analyze the return light. It should be noted that since the return light cannot pass through the reflective surface 11 of the beam splitter 1, only the return light around the periphery of the beam splitter 1 can pass through the filter 2.

[0062] Exemplarily, the fixing block 3 is, for example, Figure 1 the wedge-shaped block as shown. One end of the wedge-shaped block connected to the beam splitter 1 has an inclined surface inclined with respect to the filter 2, so as to be inclined at a specified angle when the beam splitter 1 is fixed on the wedge-shaped block. In other words, the inclined surface of the wedge-shaped block determines the inclination angle of the reflective surface 11. It is easy to understand that the inclination angle of the reflective surface 11 should satisfy that the outgoing light emitted in the first outgoing light direction a1 can be reflected to the second outgoing light direction a2 and emitted.

[0063] Exemplarily, the above-mentioned fixing block 3 is made of, for example, a metal material, a plastic material or a glass material.

[0064] Exemplarily, the above-mentioned filter 2 is, for example, a glass lens with a filter film plated on its surface, and the filter film can cut off the unnecessary wavelength bands in the return light.

[0065] Exemplarily, during the installation process of the beam splitting device, the fixing block 3 can be first fixed in the non-light-transmitting area of the filter 2, and then the beam splitter 1 is fixed on the end face of the fixing block 3. Preferably, the fixing block 3 and the filter 2, and the beam splitter 1 and the fixing block 3 are connected by, for example, an adhesive bonding method.

[0066] In some embodiments, the beam splitting device further includes a light-shielding component 4. The light-shielding component 4 includes a plurality of light-shielding sheets, and the light-shielding sheets are arranged on the periphery of the beam splitter 1. Each light-shielding sheet is arranged parallel to the preset return light direction b, used to block the return light deviating from the preset return light direction b, and can avoid blocking the return light along the preset return light direction b. Specifically, as Figure 4As shown in the figure, since the directions of the return light entering from the transceiver port of the lidar are diverse, there is a part of the return light that does not shoot towards the surface of the rotating mirror device 5. However, the return light that does not pass through the rotating mirror device 5 will surely not shoot towards the beam splitter 1 in the preset return light direction b, and thus stray light will be formed, resulting in a lot of noise points in the laser signal received by the receiving device 7. Moreover, due to various interference factors in the external environment, some of the return light entering from the transceiver port of the lidar will not enter along the preset return light direction b after being reflected by the rotating mirror device 5, but will deviate from the preset return light direction b; moreover, a part of the return light will deviate from the preset return light direction b and shoot towards the edge of the beam splitter 1 after being reflected by the rotating mirror device 5, and further enter the light-transmitting area of the filter 2 to form stray light. The light-shielding component 4 proposed in this embodiment can block the above-mentioned reflected stray light and unreflected stray light, prevent it from passing through the filter 3, and further ensure that the return light entering the receiving device 7 is all the light incident in the preset return light direction b, thereby reducing the noise points in the received signal and further improving the accuracy of the detection result.

[0067] In some preferred embodiments, all the light-shielding sheets are made of light-absorbing materials.

[0068] In some embodiments, the multiple light-shielding sheets can be divided into a first light-shielding sheet group and a second light-shielding sheet group. The first light-shielding sheet group and the second light-shielding sheet group can include a single light-shielding sheet or multiple light-shielding sheets.

[0069] As Figure 5 shown, the light-shielding sheet 41 (hereinafter simply referred to as "the first light-shielding sheet 41") in the first light-shielding sheet group is arranged on the side of the beam splitter 1 close to the transmitting device 6; the first light-shielding sheet 41 is not only used to block the return light deviating from the preset return light direction b, but also used to block a part of the first outgoing light deviating from the first outgoing light direction a1. Specifically, since the actually emitted outgoing light of the transmitting device 6 is a scattered light beam, which includes a part of the first outgoing light emitted along the first outgoing light direction a1 and the first outgoing light deviating from the first outgoing light direction a1, the outgoing light deviating from the first outgoing light direction a1 may not reach the reflecting surface 11 of the beam splitter 1, but will shoot from the filter 2 towards the receiving device 7, thus causing crosstalk between the received and transmitted light rays. Therefore, arranging the first light-shielding sheet 41 on the side of the beam splitter 1 close to the transmitting device 6 can block the first outgoing light deviating from the first outgoing light direction a1 from shooting towards the filter 2, thereby avoiding the occurrence of the problem of crosstalk between the received and transmitted light rays.

[0070] In some specific embodiments, as Figure 5 shown, the first light-shielding sheet 41 is arranged perpendicular to the first outgoing light direction a1. Moreover, as Figure 6As shown in the figure, the first light-shielding sheet 41 has a hollow portion and a first light-shielding portion; the hollow portion faces the reflective surface 11 of the beam splitter 1 and is used for the transmitted light to pass through. The first light-shielding portion is disposed around the hollow portion and is used for shielding a part of the first transmitted light that deviates from the first light-emitting direction a1 in the transmitted light.

[0071] Preferably, the width of the first light-shielding portion satisfies that it can at least shield the gap between the edge of the beam splitter 1 close to the transmitting device 6 and the filter 2.

[0072] As Figure 5 shown in the figure, the filter 42 in the second light-shielding sheet group (hereinafter referred to as "the second light-shielding sheet 42") is disposed on the other sides of the beam splitter 1 except for the side close to the transmitting device 6.

[0073] Exemplarily, as Figure 5 shown in the figure, the second light-shielding sheet 42 can be fixed on the filter 2.

[0074] Since the existing light-absorbing material cannot completely absorb the light, but will absorb and lose most of the light reaching the surface of the light-absorbing material, and there will still be a small amount of light reflected on the surface of the light-absorbing material. Therefore, even if the above light-shielding sheet is made of a light-absorbing material, there will still be a small amount of reflected light reflected on the surface of the light-shielding sheet.

[0075] To solve this problem, in some alternative embodiments, a plurality of second light-shielding sheets 42 are disposed on the side of the beam splitter 1 close to the transceiver port of the lidar and are arranged at intervals in a direction perpendicular to the preset echo direction b. In this way, the echo light deviating from the preset echo direction b can be reflected multiple times between adjacent second light-shielding sheets 42 after hitting the plurality of second light-shielding sheets 42 and can be absorbed multiple times. Finally, only a very small amount of echo light not along the preset echo direction b will enter the filter 2, so that the stray light received by the receiving device 7 is as little as possible.

[0076] Moreover, as Figure 5 and Figure 7 shown in the figure, the length of the second light-shielding sheet 42 farther away from the beam splitter 1 in the preset echo direction b is smaller, that is, the second light-shielding sheet 42 farther away from the beam splitter 1 is narrower, so as to reduce the overall volume of the beam splitting device and reduce the manufacturing cost on the premise of ensuring the shielding effect on the echo light in the non-preset echo direction b.

[0077] Exemplarily, as Figure 5 shown in the figure, the second light-shielding sheet 42 closest to the beam splitter 1 is connected to the edge of the beam splitter 1 to avoid a gap between the second light-shielding sheet 42 and the beam splitter 1, so as to prevent part of the echo light from obliquely entering the filter 2 after passing through the gap between the second light-shielding sheet 42 and the beam splitter 1.

[0078] Exemplarily, the number of the second light-shielding sheets 42 is, for example, three.

[0079] In some embodiments, as Figure 5 shown, the second light-shielding sheet group further has a light-shielding sheet 43 (hereinafter referred to as "the third light-shielding sheet 43") disposed between the first light-shielding sheet 41 and the beam splitter 1, and the third light-shielding sheet 43 is cooperatively connected with the first side surface 13 to block the light on the backlight side of the beam splitter 1, thereby preventing the light from entering the filter 2 located on the backlight side of the beam splitter 1. In this way, when the return light deviating from the preset echo direction b is reflected by the first light-shielding sheet 41 towards the filter 2, the second light-shielding portion can block it to prevent stray light from entering the filter 2.

[0080] Exemplarily, the third light-shielding sheet 43 can be fixed on the filter 2, that is, the third light-shielding sheet 43 can be installed between the backlight surface 12 and the filter 2.

[0081] Exemplarily, as Figure 8 shown, the third light-shielding sheet 43 has a groove portion and a second light-shielding portion capable of blocking light. The groove portion corresponds to the shape of the beam splitter 1 to be capable of cooperatively connecting with the first side surface 13; the second light-shielding portion can be connected to the surface of the filter 2 to completely block the gap between the backlight surface 12 and the filter 2.

[0082] As another technical solution, this embodiment further provides a lidar, as Figure 1 shown, which includes a rotating mirror device 5, a transmitting device 6, a receiving device 7, and the beam splitting device as described above. Among them, the light outlet of the transmitting device 6 is arranged facing the beam splitter 1 of the beam splitting device, and the transmitting device 6 can emit a first emitted light along the first light-emitting direction a1. The beam splitting device is used to reflect the first emitted light into a second emitted light emitted in the second light-emitting direction a2 and can allow the return light to pass through, so that the return light is transmitted towards the receiving device 7, thereby separating the emitted light and the return light.

[0083] The rotating mirror device 5 is used to reflect the second emitted light to the surface of an external object and is also used to reflect the return light incident from the external environment towards the beam splitting device. The receiving device 7 is used to receive the return light to obtain information such as the distance and speed of the external object by analyzing the return light.

[0084] Moreover, the lidar in this embodiment further includes a housing (not shown in the figure), which surrounds the peripheries of the above-mentioned multiple components, is used to protect the components inside, and can play a role in isolating external light interference. The transceiver port of the lidar is opened at a position corresponding to the rotating mirror device 5 on the housing for the second emitted light to be emitted and for the return light reflected from the surface of the external object to enter.

[0085] In some embodiments, as Figure 1As shown, the transmitting device 6 includes a laser source 61 and a transmitting lens group 62. Among them, the laser source 61 is, for example, a Vertical-Cavity Surface-Emitting Laser (VCSEL) or, for example, an Edge-Emitting Laser (EEL). The light-emitting direction of the laser source 61 is set to the above-mentioned first light-emitting direction a1. The transmitting lens group 62 includes a plurality of transmitting lenses located on the light-emitting side of the laser source 61, and the optical axes of the plurality of transmitting lenses are all directly opposite to the light-emitting port of the laser source 61, and the optical axes of the plurality of transmitting lenses are all parallel to the first light-emitting direction a1. The transmitting lenses are used to collimate the light emitted by the laser source 61 to form a vertical field of view parallel to the first light-emitting direction a1.

[0086] Preferably, the exit pupil position of the transmitting lens group 62 is formed on the reflecting surface 11 of the beam splitter 1.

[0087] Exemplarily, the above-mentioned transmitting lenses are, for example, glass lenses or plastic lenses.

[0088] In some embodiments, the circumferential surface of the rotating mirror device 5 has a multi-faceted mirror, and the rotating mirror device 5 is used to rotate around a specified axis to drive the multi-faceted mirror to rotate.

[0089] Exemplarily, the number of reflecting mirrors is, for example, 3 or 4.

[0090] In some embodiments, as Figure 1 As shown, the receiving device 7 includes a receiver 71, a receiving lens group 72, and a reflector 73. Among them, the receiver 71 is used to receive the echo light. The receiving lens group 72 is arranged on the side of the beam splitter 1 away from the rotating mirror device 5, and the optical axis of the receiving lens group 72 is parallel to the preset echo direction b. Specifically, the receiving lens group 72 includes at least one receiving lens, and the receiving lens can converge the received echo light incident in the preset echo direction b so that it converges to a preset position; it is easy to understand that the echo light incident in a non-preset echo direction b cannot be focused at the preset position, thereby forming stray light. And since the beam splitting device described above is adopted in this embodiment, it can reduce the echo light in the non-preset echo direction b from entering the receiving device 7, so the received stray light can be reduced.

[0091] The reflector 73 is used to reflect the light passing through the receiving lens group 72 to the receiving port of the receiver 71 to turn the echo light path and reduce the volume of the receiving device 7, thereby reducing the overall volume of the lidar.

[0092] Exemplarily, the above-mentioned receiver 71 is, for example, a photosensitive detector, which can detect the echo energy and the echo time.

[0093] As described above, for the beam splitter and lidar provided in this embodiment, by using a beam splitter with an inclined side surface, interference of the beam splitter with the emitted light and the echo light can be avoided, so that stray light entering the receiving device can be reduced. Moreover, this embodiment also proposes to provide a light shield parallel to the preset echo direction on the periphery of the beam splitter to block the echo light in non-preset echo directions, so that stray light entering the receiving device can be further reduced, thereby improving the accuracy of the detection result.

[0094] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

1. A spectroscopic device, applied to lidar; characterized in that, Including: A beam splitter; The beam splitter has opposite reflective surface and backlight surface. The reflective surface is arranged facing the rotary mirror device and the transmitting device of the lidar, and is used for reflecting the first outgoing light emitted by the transmitting device along the first light-emitting direction to obtain the second outgoing light along the second light-emitting direction; the backlight surface is arranged facing the receiving device of the lidar; The beam splitter further has a first side surface and a plurality of second side surfaces located at the edges of the reflective surface and the backlight surface. The first side surface is connected to one side edge of the reflective surface close to the transmitting device, and the plurality of second side surfaces are connected to the remaining side edges of the reflective surface; The first side surface is inclined with respect to the reflective surface, and the first side surface does not block the first outgoing light; the plurality of second side surfaces are inclined or perpendicular to the reflective surface, and the second side surfaces do not block the return light along the preset return light direction.

2. The spectroscopic device according to claim 1, characterized in that A first included angle is formed between the first side surface and the reflective surface, and the first included angle satisfies that in a plane perpendicular to the first light-emitting direction, the orthographic projection of the reflective surface completely covers the orthographic projection of the first side surface; A second included angle is formed between each of the plurality of second side surfaces and the reflective surface, and the second included angle satisfies that in a plane perpendicular to the preset return light direction, the orthographic projection of the reflective surface completely covers the orthographic projection of the second side surface.

3. The spectroscopic device according to claim 1, characterized in that Also included are a filter and a fixing block; One end of the fixing block is fixedly connected to the filter, and the other end of the fixing block is used for fixedly connecting to the backlight surface; The filter can allow the return light to pass through, so that the return light is directed to the receiving device.

4. The spectroscopic device according to claim 1, characterized in that, Also included is a light-shielding component; the light-shielding component includes a plurality of light-shielding sheets arranged on the periphery of the beam splitter; each light-shielding sheet is arranged parallel to the preset return light direction to block the return light deviating from the preset return light direction.

5. The spectroscopic device according to claim 4, characterized in that, The plurality of light-shielding sheets are divided into a first light-shielding sheet group and a second light-shielding sheet group; wherein, The light-shielding sheets in the first light-shielding sheet group are arranged on the side of the beam splitter close to the transmitting device; the light-shielding sheets in the first light-shielding sheet group are also used for blocking the first outgoing light deviating from the first light-emitting direction; The light-shielding sheets in the second light-shielding sheet group are arranged on other sides of the beam splitter.

6. The spectroscopic device according to claim 5, wherein The light-shielding sheets in the first light-shielding sheet group are arranged perpendicular to the first light-emitting direction; The light-shielding sheets in the first light-shielding sheet group have a hollow part and a first light-shielding part; the hollow part is opposite to the reflective surface and is used for allowing the outgoing light to pass through; The first light-shielding part is arranged around the hollow part to block a part of the first outgoing light deviating from the first light-emitting direction.

7. The spectroscopic device according to claim 5, characterized in that There are a plurality of light-shielding sheets in the second light-shielding sheet group arranged on the side of the beam splitter close to the transceiver port of the lidar, and are arranged at intervals along the direction perpendicular to the preset return light direction, and the length of the light-shielding sheet farther away from the beam splitter in the preset return light direction is smaller.

8. The spectroscopic device according to claim 6, characterized in that, The light-shielding sheet in the second light-shielding sheet group is disposed between the first light-shielding sheet group and the beam splitter, and the light-shielding sheet is cooperatively connected to the first side surface to block the light incident on the backlight side of the beam splitter.

9. The spectroscopic device according to any one of claims 5-8, characterized in that, All the light-shielding sheets are made of light-absorbing materials.

10. The spectroscopic device according to claim 2, characterized in that, The angular ranges of the first included angle and the second included angle are both 10° to 60°.

11. A lidar, characterized in that, It includes a rotating mirror device, a transmitting device, a receiving device, and the beam splitting device according to any one of claims 1-10; wherein, The light outlet of the transmitting device is arranged towards the beam splitting device, and the transmitting device can emit first emitted light along a first light-emitting direction; the beam splitting device is used to reflect the first emitted light into second emitted light along a second light-emitting direction and can allow the return light to pass through. The rotating mirror device is used to reflect the second emitted light to the surface of an external object and is also used to reflect the return light incident from the external environment towards the beam splitting device. The receiving device is used to receive the return light.

12. The lidar according to claim 11, wherein, The receiving device includes a receiver, a receiving lens group, and a reflector; wherein, the receiver is used to receive the return light. The receiving lens group is arranged on the side of the beam splitter away from the rotating mirror device, and the optical axis of the receiving lens group is parallel to the preset return light direction. The reflector is used to reflect the light passing through the receiving lens group to the receiving port of the receiver.

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