Laser emitting device and laser radar system

Abstract

The invention provides a laser emitting device. The laser emitting device comprises a laser device, a first reflecting mirror, a rotating mirror and an emitting lens structure used for collimating light beams emitted by the laser device. The first reflector is located in an emission light path between the emission lens structure and the rotating mirror, deflects relative to the normal of the initial position of the first reflector according to a preset first angle range, and is used for reflecting an emission light beam emitted from the emission lens structure to the rotating mirror in the deflection process. On the premise that the overall performance of the laser emitting device is not changed, the number of lasers can be fully reduced, the cost is reduced, the heat dissipation performance is improved, and the vertical field angle range and the longitudinal angle resolution of a laser radar system are improved. The embodiment of the invention further provides a laser radar system.

Description

Technical Field

[0001] The present disclosure relates to the field of optoelectronic technology, and in particular to a laser emitting device and a laser radar system. Background Art

[0002] Most common LiDAR systems are rotating mirror optical path systems, where the horizontal field of view of the rotating mirror LiDAR system is achieved by rotating the mirror, and the vertical field of view is achieved by vertically arranging the lasers in the transmitting optical path. The vertical field of view angle range and angular resolution are both achieved by arranging the lasers in a high density in the vertical direction, that is, there is a high demand for the number of lasers in the vertical direction, which leads to problems such as increased light source costs and poor heat dissipation. Summary of the invention

[0003] The present disclosure provides a laser emitting device and a laser radar system.

[0004] In a first aspect, an embodiment of the present disclosure provides a laser emitting device, including a laser, a first reflector, a rotating mirror, and an emitting lens structure for collimating an outgoing beam of the laser;

[0005] The first reflector is located in the emission light path between the emission lens structure and the rotating mirror, and is deflected relative to the normal of the initial position of the first reflector according to a preset first angle range, so as to reflect the emission light beam emitted from the emission lens structure to the rotating mirror during the deflection process.

[0006] On the other hand, an embodiment of the present disclosure also provides a laser radar system, including the laser emitting device as described above.

[0007] The laser emitting device provided by the embodiment of the present disclosure includes a laser, a first reflector, a rotating mirror, and an emitting lens structure for collimating the laser output light beam; the first reflector is located in the emission light path between the emitting lens structure and the rotating mirror, and is deflected relative to the normal of the initial position of the first reflector according to a preset first angle range, and is used to reflect the emission light beam emitted from the emitting lens structure to the rotating mirror during the deflection process. Under the premise that the overall performance of the laser emitting device remains unchanged, the number of lasers can be fully reduced, the cost can be reduced, the heat dissipation performance can be improved, and the vertical field of view angle range and longitudinal angular resolution of the laser radar system can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a schematic diagram of a laser emitting device according to an embodiment of the present disclosure;

[0009] Figure 2 is a schematic diagram of a coaxial laser radar system according to an embodiment of the present disclosure;

[0010] Figure 3is a schematic diagram of a non-coaxial laser radar system according to an embodiment of the present disclosure;

[0011] Figure 4 A schematic diagram of a laser radar system with a reflector disposed at a receiving end according to an embodiment of the present disclosure;

[0012] Figure 5 A schematic diagram of a laser radar system with a common reflector for transmitting and receiving according to an embodiment of the present disclosure;

[0013] Figure 6 Schematic diagram of the composition of the laser radar system of an embodiment of the present disclosure. DETAILED DESCRIPTION

[0014] Example embodiments will be described more fully below with reference to the accompanying drawings, but the example embodiments may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. On the contrary, the purpose of providing these embodiments is to make the present disclosure thorough and complete and to enable those skilled in the art to fully understand the scope of the present disclosure.

[0015] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0016] The terms used herein are only used to describe specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It will also be understood that when the terms "comprising" and / or "made of" are used in this specification, the presence of the features, wholes, steps, operations, elements and / or components is specified, but the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof is not excluded.

[0017] The embodiments described herein may be described with reference to plan views and / or cross-sectional views by means of idealized schematic diagrams of the present disclosure. Therefore, the example illustrations may be modified according to manufacturing techniques and / or tolerances. Therefore, the embodiments are not limited to the embodiments shown in the accompanying drawings, but include modifications of the configurations formed based on the manufacturing process. Therefore, the regions illustrated in the accompanying drawings have schematic properties, and the shapes of the regions shown in the figures illustrate the specific shapes of the regions of the elements, but are not intended to be limiting.

[0018] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted as having an idealized or overly formal meaning unless explicitly defined as such herein.

[0019] The present disclosure provides a laser emitting device, such as Figure 1 As shown, the laser emitting device comprises a laser 1, a first reflector 2, a rotating mirror 3 and an emitting lens structure 4, wherein the emitting lens structure 4 is used to collimate the emitted light beam of the laser 1. The first reflector 2 is located in the emission light path between the emitting lens structure 4 and the rotating mirror 3, and is deflected relative to the normal of the initial position of the first reflector 2 according to a preset first angle range, and is used to reflect the emission light beam emitted from the emitting lens structure 4 to the rotating mirror 3 during the deflection process.

[0020] Laser 1 is the light source of the laser radar system. It can be a Vcsel discretely arranged laser or other lasers, such as EEL or optical fiber. There are multiple lasers 1. In the embodiment of the present disclosure, m lasers 1 are arranged vertically to achieve a vertical field of view. It should be noted that each laser 1 can also be arranged horizontally. The emission lens structure 4 is used to collimate the emission light beam emitted from the laser 1. The initial position of the first reflector 2 is as shown in FIG. Figure 1 As shown, the first reflector 2 is tilted and arranged outside the focal length of the emitting lens structure 4. The normal line of the initial position of the first reflector 2 is as shown in FIG. Figure 1 As shown by the middle dotted line, the first reflector 2 can swing up and down in the vertical direction within a preset first angle range, and during the swinging process, the emission light beam emitted from the emission lens structure 4 is reflected to the rotating mirror 3. The rotating mirror 3 includes a plurality of reflecting surfaces, and the reflecting mirror surfaces rotate around the rotating axis. The rotating mirror 3 uses the reflecting surfaces to reflect the emission light beam emitted from the first reflector 2.

[0021] Figure 1 The solid arrows represent the optical path of the emitted light beam when the first reflector 2 is in the initial position, and the dotted arrows represent the optical path of the emitted light beam after the first reflector 2 is deflected by a certain angle. Figure 1 As shown, after the first reflector 2 is deflected relative to the normal line of the initial position of the first reflector (ie, vertically deflected), the optical path of the emitted light beam is also deflected vertically on the reflection surface of the rotating mirror 3 accordingly.

[0022] The m lasers 1 arranged discretely in the vertical direction emit collimated light beams after passing through the emission lens structure 4, forming multi-angle collimated light, and realizing beam collimation. The emission light beam collimated by the emission lens structure 4 is deflected and reflected by the first reflector 2 to the rotating mirror 3. Among them, the first reflector 2 can be deflected quickly to change the incident angle of the emission light beam, so that the multi-angle collimated emission light beam emitted from the emission lens structure 4 can be emitted at more angles after the timing control of different deflection angles of the first reflector 2. For example: if there are m lasers 1, and there are m angles of collimated emission light beams emitted through the emission lens structure 4, if the first reflector 2 is not provided, then the longitudinal angular resolution of the laser radar system is m; the first reflector 2 has k deflection angles, that is, the preset first angle range is (0, k], then the emission light beam reflected by the first reflector 2 has m*k angles of collimated light beams, so that the longitudinal angular resolution of the laser radar system is m*k, that is, the longitudinal angular resolution of the laser radar system is improved. The disclosed embodiment only requires a small number of lasers 1, and is matched with the first reflector 2. That is, more emission light beam angles can be achieved without losing the vertical field of view angle and longitudinal angular resolution. When the first reflector 2 is vertically deflected, the emission light beam reflected by the first reflector 2 forms a vertical emission field of view of the laser radar system. The emission light beam is reflected on the rotating mirror 3, and the rotating mirror 3 rotates, thereby deflecting the emission light beam in the horizontal direction to form a horizontal emission field of view. By using the first reflector 2 to quickly reflect light, emission light beams with multiple reflection angles are obtained to form a vertical emission field of view, which reduces the demand for the number of lasers in the light source, saves costs, and reduces the difficulty of heat dissipation of the light source.

[0023] The laser emitting device provided by the embodiment of the present disclosure includes a laser 1, a first reflector 2, a rotating mirror 3, and an emitting lens structure 4 for collimating the emitted light beam of the laser 1; the first reflector 2 is in the emission light path between the emitting lens structure 4 and the rotating mirror 3, and is deflected according to the normal line relative to the initial position of the first reflector 2 in a preset first angle range, and is used to reflect the emission light beam emitted from the emitting lens structure 4 to the rotating mirror 3 during the deflection process. Under the premise that the overall performance of the laser emitting device remains unchanged, the number of lasers can be fully reduced, the cost can be reduced, the heat dissipation performance can be improved, and the vertical field of view angle range and longitudinal angular resolution of the laser radar system can be improved.

[0024] In some embodiments, the first reflector 2 is a fast reflector, which has a fast response speed and high control accuracy.

[0025] In some embodiments, the first reflector 2 may be a piezoelectric ceramic reflector. The piezoelectric ceramic reflector is an important part of the optoelectronic precision tracking system and can accurately control the direction of the light beam.

[0026] In some embodiments, the emission lens structure 4 may be a single lens, for example, a superlens (nano grating), or the emission lens structure 4 may be a lens group including a plurality of lenses.

[0027] The present disclosure also provides a laser radar system, such as Figure 2 and Figure 3 As shown, the laser radar system includes a laser emitting device 10 and a laser receiving device 20 for receiving a light beam. The laser emitting device 10 is the laser emitting device as described above.

[0028] In some embodiments, the laser receiving device 20 may include a receiving chip 201 and a receiving lens 202 . The receiving lens 202 may be a receiving lens barrel for focusing the receiving light beam. The focused receiving light beam is focused on the receiving chip 201 by the receiving lens.

[0029] The laser radar system of the embodiment of the present disclosure includes a laser emitting device 10 and a laser receiving device 20 for receiving a receiving light beam, wherein the laser emitting device includes a laser 1, a first reflector 2, a rotating mirror 3, and a transmitting lens structure 4 for collimating the light beam emitted by the laser 1; the first reflector 2 is in the transmitting light path between the transmitting lens structure 4 and the rotating mirror 3, and is deflected according to the normal line relative to the initial position of the first reflector 2 in a preset first angle range, and is used to reflect the transmitting light beam emitted from the transmitting lens structure 4 to the rotating mirror 3 during the deflection process. Under the premise that the overall performance of the laser emitting device 10 remains unchanged, the number of lasers can be fully reduced, the cost can be reduced, the heat dissipation performance can be improved, and the vertical field of view angle range and longitudinal angular resolution of the laser radar system can be improved.

[0030] In some embodiments, Figure 2 and Figure 3 As shown, the laser radar system further includes a laser transceiver separation device 30, which is arranged in the receiving optical path, or in the transmitting optical path and the receiving optical path, and is used to change the receiving optical path of the receiving light beam. The laser transceiver separation device 30 can separate the transmitting light beam from the receiving light beam, so that the optical path of the receiving light beam emitted from the laser transceiver separation device 30 is different from the optical path of the transmitting light beam entering the laser transceiver separation device 30.

[0031] In some embodiments, the laser transmit-receive separation device 30 is a third reflector, which includes an opening 301 and a non-opening area 302. The opening 301 is located in the transmitting light path, and is used to transmit the transmitting light beam to the rotating mirror 3; the non-opening area 302 is at least partially located in the receiving light path, and is used to reflect at least part of the receiving light beam reflected by the rotating mirror 3 to the laser receiving device 20.

[0032] The laser radar system of the embodiment of the present disclosure may be as follows Figure 2The coaxial optical transceiver system shown can also be Figure 3 The non-coaxial optical transceiver system shown.

[0033] In the case where the laser radar system is a coaxial optical transceiver system, such as Figure 2 As shown, the optical path of the incident light beam incident on the rotating mirror 3 is the same as the optical path of the receiving light beam emitted from the rotating mirror 3, and the optical path of the emission light beam emitted from the rotating mirror 3 is the same as the optical path of the receiving light beam incident on the rotating mirror 3. The emission light beam reflected by the first reflector 2 is transmitted through the opening 301 of the third reflector and enters the rotating mirror 3 for scanning. Part of the receiving light beam is reflected by the rotating mirror 3 and is incident on the non-opening area 302 of the third reflector. The non-opening area 302 reflects the receiving light beam, and the reflected receiving light beam is incident on the laser receiving device 20. It should be noted that after the receiving light beam is reflected by the rotating mirror 3, most of it will be incident on the non-opening area 302 of the third reflector, and a small part will be transmitted from the opening 301 of the third reflector. The transmitted receiving light beam cannot be received by the laser receiving device 20, so there is a small amount of energy loss.

[0034] In the case where the laser radar system is a non-coaxial optical transceiver system, such as Figure 3 As shown, the optical path of the incident light beam incident on the rotating mirror 3 is different from the optical path of the receiving light beam emitted from the rotating mirror 3, and the optical path of the emission light beam emitted from the rotating mirror 3 is different from the optical path of the receiving light beam incident on the rotating mirror 3. The emission light beam reflected by the first reflector 2 is transmitted through the opening 301 of the third reflector and enters the upper half of the rotating mirror 3 for scanning. The receiving light beam is reflected by the lower half of the rotating mirror 3 and is incident on the non-opening area 302 of the third reflector, and the non-opening area 302 reflects the receiving light beam to the laser receiving device 20.

[0035] In some embodiments, the laser transceiver separation device 30 may also be a second reflector, and the laser transceiver separation device 30 is located in the receiving optical path, and is used to reflect the receiving light beam reflected by the rotating mirror 3 to the laser receiving device 30. In other words, the laser transceiver separation device 30 may also be a second reflector without an opening, and the second reflector is located in the receiving optical path, and is used to reflect the receiving light beam emitted from the rotating mirror 3 to the laser receiving device 20. The second reflector is not in the transmitting optical path, so the transmitting light beam reflected by the first reflector 2 can be directly incident on the rotating mirror 3, so that the transmitting light beam and the receiving light beam can also be separated.

[0036] In some embodiments, Figure 4As shown, the laser radar system may further include a fourth reflector 40, which is located in the receiving light path between the laser transceiver separation device 30 and the laser receiving device 20, and is deflected relative to the normal of the initial position of the fourth reflector 40 according to a preset second angle range, and is used to reflect the receiving light beam emitted from the laser transceiver separation device 30 to the laser receiving device 20 during the deflection process.

[0037] The initial position of the fourth reflector 40 is as follows Figure 4 As shown, the fourth reflector 40 is tilted, and the reflective surface of the fourth reflector 40 faces the laser transceiver separation device 30. The normal line of the initial position of the fourth reflector 40 is as shown in FIG. Figure 4 As shown by the middle dotted line, the fourth reflector 40 can swing up and down in the vertical direction within a preset second angle range, and during the swinging process, it reflects the receiving light beam emitted from the laser transceiver separation device 30 to the laser receiving device 20.

[0038] In some embodiments, the fourth reflector 40 is a fast reflector, which has a fast response speed and high control accuracy.

[0039] In some embodiments, the fourth reflector 40 may be a piezoelectric ceramic reflector. The piezoelectric ceramic reflector is an important part of the optoelectronic precision tracking system and can accurately control the direction of the light beam.

[0040] A piezoelectric ceramic reflector is arranged in the receiving optical path. The piezoelectric ceramic reflector can be rapidly deflected at multiple angles, thereby reducing the number of receiving chips 201 and reducing costs.

[0041] In order to further reduce costs, in the embodiment of the present disclosure, the laser transceiver separation device 30 may not be provided, but the transmitting light beam and the receiving light beam may share a reflector, that is, a first reflector 2 is used to quickly switch the initial position of the first reflector 2 in the transmitting light path and the initial position in the receiving light path, so as to realize the separation of the transmitting light path and the receiving light path.

[0042] Therefore, in some embodiments, Figure 5 As shown, after completing the reflection of the emission light beam to the rotating mirror 3, the first reflector 2 is deflected by a first preset angle relative to the normal of the current position to switch to the first target position, and is deflected relative to the normal of the first target position according to a preset third angle range, so as to reflect the receiving light beam to the laser receiving device 20 during the deflection process.

[0043] The first target position is the initial position of the first reflector 2 in the receiving light path, that is, the initial position of the first reflector 2 reflecting the receiving light beam, that is, Figure 5 The dotted line shows the position of the first reflector 2. It should be noted that, in this embodiment, the laser receiving device 20 is arranged below the laser 1.

[0044] Figure 5 The working process of the transmitting end of the laser radar system shown is as described above, and its receiving optical path and transmitting optical path share the same first reflector 2. When the receiving light beam is reflected back to the laser radar system through the outside world, it is first deflected and reflected to the first reflector 2 by the rotating mirror 3. At this time, the first reflector 2 makes a rapid angle switch, deviating the echo receiving light beam from the original transmitting optical path, and enters the receiving lens 202 of the laser receiving device 20. After being transmitted through the receiving lens 202, it is received by the receiving chip 201, and thus detected and identified. The laser radar system in which the receiving optical path and the transmitting optical path share the same first reflector 2 can reduce the number of lasers 1 and receiving chips 201, thereby saving costs; at the same time, no additional laser transceiver separation device 30 is required, thereby reducing the volume of the laser radar system and meeting the demand of vehicle-mounted radar for small-volume radars.

[0045] In some embodiments, after completing the reflection of the emission light beam to the rotating mirror 3, the first reflector 2 can also deflect the second preset angle in the current setting direction to switch to the second target position, and deflect relative to the normal of the second target position according to the preset third angle range, so as to reflect the receiving light beam to the laser receiving device 20 during the deflection process. In other words, the first reflector 2 is not as Figure 5 The deflection is not shown in the vertical direction, but in the side direction to switch to the second target position.

[0046] The second target position is the initial position of the first reflector 2 in the receiving light path, that is, the initial position where the first reflector 2 reflects the receiving light beam. It should be noted that in this embodiment, the laser receiving device 20 is disposed at a side of the laser 1 .

[0047] The first reflector 2 deflects in different directions in the transmitting light path and the receiving light path, so that the layout of various components inside the laser radar system is more flexible to meet different needs.

[0048] The laser emitting device and laser radar system of the disclosed embodiment are provided with a first reflector 2 in the laser emitting device 10, and the first reflector 2 is used to guide the emission light beam, or to guide the emission light beam and the receiving light beam, so as to reduce the number of lasers 1; at the same time, the laser emitting device 10 can be applied to coaxial laser radar systems and non-coaxial laser radar systems.

[0049] Reference below Figure 6 The laser radar system 100 according to an embodiment of the present disclosure is described. Figure 6 The XYZ coordinate system is marked in . Figure 6FIG. 1 is a schematic diagram showing the components of a laser radar system 100 according to an embodiment of the present disclosure. The laser radar system 100 can be used to detect the distance and speed of a target object.

[0050] In an embodiment of the present disclosure, the laser radar system 100 may include a transmitting device 110 , a scanning device 120 , and a receiving device 130 .

[0051] In various embodiments, the transmitting device 110 can be configured to transmit an emission light beam having a uniform energy distribution. Here, uniform energy distribution can also be interpreted as uniform illumination or light intensity. In some embodiments, such an emission light beam having a uniform energy distribution can be obtained by shaping (homogenizing) using an emission optical system 112, which will be discussed in detail later.

[0052] In various embodiments, the emission light beam is divergent in a first direction perpendicular to the optical axis of the emission device 110, with a corresponding first divergence angle.

[0053] Furthermore, in various embodiments, the emission light beam is either parallel in a second direction perpendicular to the optical axis of the emission device and perpendicular to the first direction, or divergent and the corresponding second divergence angle is smaller than a preset threshold.

[0054] In practical applications, the first direction ( Figure 6 The Y-axis direction shown in the figure) can usually be referred to as the vertical direction (V direction), while the second direction ( Figure 6 The Z-axis direction shown in the figure may generally refer to the horizontal direction (H direction). For ease of understanding, the following description is made by taking the case where the first direction corresponds to the vertical direction and the second direction corresponds to the horizontal direction as an example. However, it is easy for those skilled in the art to understand that the present disclosure is not limited thereto. For example, the first direction may also refer to the horizontal direction, and the second direction may refer to the vertical direction.

[0055] On the one hand, the emitted light beam diverges in the vertical direction, and the corresponding first divergence angle is defined as Δθ V That is, the emitted light beam is at an angle Δθ in the vertical direction. V Fan-shaped beam emission.

[0056] On the other hand, the emission light beam may be parallel in the horizontal direction. Alternatively, the emission light beam may also be divergent in the horizontal direction, but the corresponding second divergence angle is less than the preset threshold. That is, the emission light beam is emitted in the horizontal direction as parallel light or at a very small angle. The selection of the preset threshold will be discussed in detail later.

[0057] That is, the emission light beam is a uniform linear or narrow rectangular light beam. As a result, the light spot projected in the field of view can appear as a narrow rectangle or even a line. The long side of the rectangle corresponds to the vertical direction, and the short side corresponds to the horizontal direction. Here, "narrow" may mean that the aspect ratio of the rectangle is greater than a preset aspect ratio threshold. Advantageously, by using an emission light beam that is linear or narrow rectangular, the laser radar system 100 disclosed in the present invention can achieve a more concentrated field of view angle energy, a longer distance detection, and a higher resolution.

[0058] The inventors of the present disclosure have recognized that an emission light beam having the above-mentioned specific illumination distribution can be obtained by shaping a laser beam emitted from a common light source.

[0059] Therefore, in some embodiments, the emission device 110 includes a light source 111 and an emission optical system 112. The emission optical system 112 is configured to shape the laser beam emitted from the light source 111 to convert it into the emission light beam.

[0060] In some embodiments, the light source 111 may be a laser, such as a solid-state laser (such as a vertical-cavity surface-emitting laser (VCSEL), an edge-emitting laser (EEL), an external-cavity diode laser (ECDL)), a laser diode, or a fiber laser. In some embodiments, the light source 111 may also include a light emitting diode (LED). However, it is easy for those skilled in the art to understand that the present disclosure does not specifically limit the type of device of the light source 111, as long as the output power of the light source 111 is large enough.

[0061] In some embodiments, the light source 111 may be an array light source. For example, the light source 111 may be a VCSEL array including a plurality of VCSELs. In a non-limiting example, the plurality of VCSELs may be configured to light up all at the same time during measurement, rather than lighting up in partitions and / or time divisions.

[0062] Alternatively, in some embodiments, the light source 111 may also be a single point light source. It is easy for those skilled in the art to understand that the present disclosure does not specifically limit the arrangement of the light source 111.

[0063] In some embodiments, the light source 111 can emit light beams in different forms, including pulsed light, continuous wave (CW) and quasi-continuous light. The operating wavelength of the light source can be 650nm to 1150nm, 800nm ​​to 1000nm, 850nm to 950nm or 1300nm to 1600nm. In some embodiments, the light source 111 can also include an optical component optically coupled to the light source 111 for collimating or focusing the light beam emitted by the light source 111. Each emitted light beam emitted by the light source 111 can be continuous light lasting a certain period of time, or it can be one or more light pulses.

[0064] In some embodiments, the emission optical system 112 may include a diffusion unit configured to diffuse and shape the input laser beam. For example, the diffusion unit may diffuse and shape the beam based on diffraction and / or refraction, etc., to emit the above-mentioned uniform linear or narrow rectangular beam. However, it is easy to understand by those skilled in the art that the present disclosure may also obtain the above-mentioned emission beam through other shaping processes.

[0065] In some embodiments, the diffusion unit may include at least one of the following optical devices: an optical diffuser, a diffractive optical element (DOE), and an aspherical cylindrical mirror. However, those skilled in the art will readily appreciate that the above devices are merely examples of the diffusion unit, and the present disclosure is not limited thereto.

[0066] In the case of using an optical diffuser or DOE to perform diffusion shaping, the emission optical system 112 may further include a collimating unit, wherein the collimating unit may be configured to collimate the laser beam emitted from the light source to obtain a collimated laser beam to be input into the diffuser or DOE.

[0067] In some embodiments, the collimating unit may include at least one of the following optical devices: a microlens or a collimating mirror. For example, the collimating unit may be an array of microlenses. However, it is easy for those skilled in the art to understand that the above devices are only examples of collimating units, and the present disclosure is not limited thereto.

[0068] In some embodiments, the laser radar system 100 further includes a transmitting and receiving separation device. The transmitting and receiving separation device may be a plane mirror 140 or a beam splitter having a hole 141. Specifically, taking a plane mirror with a hole as an example, the plane mirror 140 uses the hole 141 to transmit the emission light beam to guide the emission light beam to the scanning device 120, and uses a mirror to reflect the receiving light beam to guide the receiving light beam to the receiving device 130. That is, the emission light beam emitted from the transmitting device 110 can be directly transmitted through the plane mirror 140 via the hole 141, and the reflected receiving light beam can be reflected by the mirror in the plane mirror 140. That is, the reverse receiving path can be separated from the forward transmitting path at the plane mirror 140. Thus, with the help of the plane mirror 140 with a hole, the laser radar system 100 can realize the coaxial transmission and reception. Advantageously, the coaxial transmission and reception can avoid the imaging position deviation problem of the return light spot of the close-range and long-range detection caused by the separation of the optical axes of the two, thereby avoiding the additional calibration caused by this problem, which is conducive to mass production of products. However, it is easy for those skilled in the art to understand that the present invention may also be a non-coaxial lidar system.

[0069] The inventors of the present disclosure have realized that the precision requirements for manufacturing and adjusting the holes of a plane reflector with holes are relatively loose, as long as the emitted light beam can pass through. On this basis, the loss of reflected light can be reduced by reducing the size of the holes.

[0070] Therefore, in some embodiments, the emission light beam is in a focused state when passing through the hole. For example, by designing the light beam characteristics of the emission light beam and / or adjusting the position of the plane reflector relative to the emission device, it can be ensured that the emission light beam is in a focused state when passing through the hole. Advantageously, by focusing the emission light beam at the hole, the hole can be minimized while ensuring that the emission light beam passes through the hole, thereby minimizing the loss of reflected light and further reducing the precision requirements for the manufacture and adjustment of the hole. However, it is easy to understand for those skilled in the art that the present disclosure is not limited to this.

[0071] The hole is usually located at the center of the plane reflector, but the present disclosure is not limited thereto. In addition, to reduce the loss of reflected light, the shape of the hole can correspond to the cross-sectional shape of the emitted light beam when passing through the hole, and therefore is not necessarily circular.

[0072] Those skilled in the art will readily appreciate that the present disclosure may also use other methods to achieve coaxial transmission and reception. However, compared to other methods such as a beam splitter, the plane reflector with holes proposed in the present disclosure can reduce light loss and improve efficiency.

[0073] In various embodiments, the scanning device 120, such as a rotating mirror, can be configured to rotate around a rotation axis oriented in a vertical direction (a first direction, the Y-axis direction in the figure) to guide the emission light beam to scan the target object in the field of view. The target object can be any object that can reflect the scanning laser within the scanning field of view of the laser radar system, such as vehicles, pedestrians, animals, road signs, obstacles, trees, shelves, furniture, etc.

[0074] After irradiating the target object, the transmitted light beam is scattered back, and a portion of it returns to the laser radar system 100 as a received light beam and is received by the receiving device 130.

[0075] In various embodiments, the receiving device 130 may be configured to receive and detect a receiving light beam returned from the target object. For example, the receiving light beam scattered and returned by the target object may return to the scanning device 120 along the original path, and then be guided by the scanning device 120 to the plane reflector 140, and then reflected to the receiving device 130 by the plane reflector 140.

[0076] In some embodiments, the receiving device 130 may include a photodetector 131. The photodetector 131 may measure the power, phase, or time characteristics of the received light and generate a corresponding current output.

[0077] In some embodiments, Figure 6 As shown, the photodetector 131 may include a plurality of photodetection units 1310 arranged along a direction. Among them, different photodetection units 1310 are configured to receive and detect light signals returned from target objects at different relative angles in the vertical direction of the field of view. The photodetector 131 may also include a receiving circuit (not shown) associated with each photodetection unit 1310. Each receiving circuit may be used to process the output electrical signal of the corresponding photodetection unit 1310.

[0078] The photodetection unit 1310 may include various forms of photodetection devices or one-dimensional or two-dimensional arrays of photodetection devices, and accordingly, the receiving circuit may be an array of one circuit or multiple circuits. In various embodiments, the photodetection device may be an avalanche diode (APD), a single photon avalanche diode (SPAD), a PN photodiode, or a PIN photodiode.

[0079] For example, the photodetection unit 1310 can be a photodetection device SPAD or a one-dimensional or two-dimensional array thereof, so the photodetector 131 is an array of SPADs. Advantageously, since the spacing between SPADs is very small and they are closely arranged, the spatial resolution can be greatly improved. Moreover, different SPADs can simultaneously and individually perform direct Time-of-Flight (dToF) measurements without the need to light up the light source in different zones and at different times, which can greatly improve the temporal resolution.

[0080] In some embodiments, the receiving device 130 may further include a receiving optical system 132. The receiving optical system 132 may be configured to image the received light onto the photodetector 131. For example, in some embodiments, the receiving optical system 132 may include a receiving lens and an aperture. The receiving lens and the aperture are located upstream of the photodetector 131 on the receiving path. For example, the receiving lens may include an imaging system lens so that the focus of the received light beam is in front of or behind the receiving surface of the photodetector or just above the receiving surface. In some cases, instead of existing as a separate component, the receiving lens may also be integrated into the photodetector 131. The aperture is used to limit the angle of incident light incident on the photodetector 131, block stray light, etc.

[0081] As described above, the light spot projected into the field of view by the laser radar system 100 can be a uniform line or a narrow rectangle extending in the vertical direction, so the received light beam returned from the target object will form a similar pattern on the receiving surface of the photodetector 131. By arranging a plurality of photodetection units 1310 correspondingly along the direction of the long side of the line or rectangle, and imaging the light returned from the target object at different relative angles in the vertical direction of the field of view to different photodetection units 1310 using the receiving optical system 132, these photodetection units 1310 can be made to correspond to the target objects at different relative angles in the vertical direction of the field of view, respectively. That is, different photodetection units 1310 are configured to receive and detect light signals returned from target objects at different relative angles in the vertical direction of the field of view. Therefore, based on the arrangement information of the photodetection unit 1310 and the parameter information of the optical system, etc., the relative angle of the corresponding target object can be accurately calculated.

[0082] Since a uniform linear (or narrow rectangular) transmitting light beam is adopted, it is only necessary to perform a simple adjustment on the laser radar system 100 so that the receiving light spot imaged by the receiving optical system 132 on the photodetector 131 can cover the receiving surface of the photodetection unit 1310 (i.e., the photosensitive surface of all photodetection units 1310), and there is no need to perform separate alignment of the transmitting module and the receiving module. Here, the receiving light spot "covering" the receiving surface can be understood as the receiving light spot at least partially overlapping with the receiving surface, so that each photodetection unit can receive the light signal returned from the target object. For example, in some embodiments, the size of the receiving light spot can be made relatively small, and can only cover a portion of the receiving surface, so that the returned light signal can be received by the photodetection unit as much as possible to reduce waste. Therefore, advantageously, the scheme proposed in the present disclosure can greatly simplify the difficulty of adjustment and is conducive to realizing automated production.

[0083] The angular resolution δθ of the laser radar system 100 in the vertical direction according to the embodiment of the present disclosure is V =Δθ V / Q, where Q is the number of photodetection units 1310 included in the photodetector 131. By reducing the emission angle Δθ V And / or increasing the number Q of the photodetection units 1310 in the photodetector 131 can reduce the angular resolution δθ in the vertical direction. V value, thereby improving the angular resolution in the vertical direction.

[0084] It is worth noting that, in some embodiments, each photodetection unit 1310 may include a plurality of photodetection devices (such as SPADs) arranged along one direction, wherein the arrangement direction of the plurality of photodetection devices is perpendicular to the arrangement direction of the plurality of photodetection units 1310. With this arrangement, the number of photodetection devices in each photodetection unit 1310 can be increased without affecting the spacing of the photodetection units 1310, thereby improving the accuracy of detection without affecting the spatial resolution.

[0085] Example embodiments have been disclosed herein, and although specific terms are employed, they are used and should be interpreted only in a general illustrative sense and not for limiting purposes. In some instances, it will be apparent to those skilled in the art that, unless otherwise expressly stated, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments. Therefore, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the scope of the invention as set forth in the appended claims.

Claims

1. A laser emitting device, characterized in that: It includes a laser, a first reflector, a rotating mirror and an emission lens structure for collimating the laser output light beam; The first reflector is located in the emission light path between the emission lens structure and the rotating mirror, and is deflected relative to the normal of the initial position of the first reflector according to a preset first angle range, so as to reflect the emission light beam emitted from the emission lens structure to the rotating mirror during the deflection process.

2. The laser emitting device according to claim 1, characterized in that: The first reflecting mirror is a fast reflecting mirror.

3. The laser emitting device according to claim 2, characterized in that: The first reflector is a piezoelectric ceramic reflector.

4. The laser emitting device according to claim 1, characterized in that: The emission lens structure is a single lens or a lens group including a plurality of lenses.

5. A laser radar system, characterized in that: It comprises a laser emitting device as described in any one of claims 1 to 4 and a laser receiving device for receiving a receiving light beam.

6. The laser radar system according to claim 5, characterized in that It also includes a laser transceiver separation device, which is arranged in the receiving optical path, or in the transmitting optical path and the receiving optical path, and is used to change the receiving optical path of the receiving light beam.

7. The laser radar system according to claim 6, characterized in that The laser transmitting and receiving separation device is a third reflector, the third reflector includes an opening and a non-opening area, the opening is located in the emission light path, and is used to transmit the emission light beam to the rotating mirror; The non-opening area is at least partially located in the receiving light path, and is used to reflect at least a portion of the receiving light beam reflected by the rotating mirror to the laser receiving device.

8. The laser radar system according to claim 6, characterized in that The laser transceiver separation device is a second reflector, and the laser transceiver separation device is located in the receiving light path, and is used to reflect the receiving light beam reflected by the rotating mirror to the laser receiving device.

9. The laser radar system according to claim 6, characterized in that: It also includes a fourth reflector, which is located in the receiving light path between the laser transceiver separation device and the laser receiving device, and is deflected relative to the normal of the initial position of the fourth reflector according to a preset second angle range, and is used to reflect the receiving light beam emitted from the laser transceiver separation device to the laser receiving device during the deflection process.

10. The laser radar system according to claim 5, characterized in that: After completing the reflection of the emission light beam to the rotating mirror, the first reflector is deflected by a first preset angle relative to the normal of the current position to switch to the first target position, and is deflected relative to the normal of the first target position according to a preset third angle range, so as to reflect the receiving light beam to the laser receiving device during the deflection process.

11. The laser radar system according to claim 5, characterized in that: After completing the reflection of the emission light beam to the rotating mirror, the first reflector is deflected by a second preset angle in the currently set direction to switch to the second target position, and is deflected relative to the normal of the second target position according to a preset third angle range, so as to reflect the receiving light beam to the laser receiving device during the deflection process.

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