Light emitting device for laser radar, design method and laser radar

Abstract

The invention provides a light emitting device for a laser radar, and the device comprises a light-emitting unit array which comprises a plurality of light-emitting units, the plurality of light-emitting units are arranged at intervals, and each light-emitting unit is configured to emit a light beam; the micro-lens array is arranged at the downstream of a light path of the light emitting unit array, the micro-lens array comprises a plurality of micro-lenses, and each micro-lens corresponds to one light emitting unit and is configured to modulate a light beam emitted by the corresponding light emitting unit; and the collimation unit is arranged at the downstream of a light path of the micro-lens array and is configured to shape the light beams modulated by the micro-lens array, so that view fields formed by the light beams emitted from the collimation unit are mutually overlapped or adjacently connected. According to the invention, the micro-lens array is arranged at the downstream of the light path of the light-emitting unit, and each micro-lens can modulate the light beam emitted by the corresponding light-emitting unit, so that the light beams emitted from the plurality of micro-lenses are shaped by the collimation unit to form view fields which are mutually overlapped or adjacently connected; therefore, part of view field energy loss caused by the interval between the adjacent light-emitting units is made up, and the continuity of the view field range and the uniformity of energy distribution are improved.

Description

Technical Field

[0001] The present invention generally relates to the field of laser radar, and in particular to a light emitting device and a design method for laser radar, and a laser radar. Background Art

[0002] LiDAR is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of a target. It is an advanced detection method that combines laser technology with photoelectric detection technology. LiDAR is widely used in autonomous driving, drones, intelligent robots, resource exploration and other fields due to its advantages such as high resolution, good concealment, strong anti-active interference ability, good low-altitude detection performance, small size and light weight.

[0003] Some laser radar light emitting devices use lasers with multiple light-emitting unit arrays. In the process design, due to the need for routing of area-based driving, the light-emitting units are arranged discontinuously, and there is an isolation area of ​​a certain size between adjacent light-emitting units (gap area, see Figure 1 In gap1 and gap2, Figure 1 The shaded area in the middle shows the partition wire pad area, that is, the PAD area, which is used to drive different partitions). The size of the isolation area depends on the thickness of the wiring and the isolation size required by the process design. The existence of the isolation area will cause a clear gap in the field of view formed by the light beams emitted by adjacent light-emitting units (refer to Figure 2 ), that is, the fields of view formed by the light beams emitted by adjacent light-emitting units are discrete and discontinuous, and the energy distribution within the field of view formed by the light beams emitted by each light-emitting unit is uneven, which will easily lead to missed detection of targets and inaccurate detection results.

[0004] Therefore, how to optimize the continuity of the field of view formed by the light beam emitted by a laser that includes multiple separately drivable light-emitting units, the uniformity of energy distribution, reduce target omissions, and improve the accuracy of detection results is a need for continuous improvement in the field of lidar.

[0005] The contents of the background technology section are merely the technologies known to the inventors and do not necessarily represent the prior art in the field. Summary of the invention

[0006] In view of one or more problems in the prior art, the present invention provides a light emitting device for laser radar, which provides a microlens array downstream of the light path of the light emitting unit, and each microlens can modulate the light beam emitted by the light emitting unit corresponding thereto, so that the light beams emitted from multiple microlenses are shaped by the collimating unit to form fields that overlap or abut each other, thereby compensating for the partial field of view energy loss caused by the interval between adjacent light emitting units, which is beneficial to improving the continuity of the field of view. The light emitting device includes:

[0007] a light emitting unit array, the light emitting unit array comprising a plurality of light emitting units, wherein the plurality of light emitting units are spaced apart from each other, and each light emitting unit is configured to emit a light beam; and

[0008] a microlens array, the microlens array being arranged downstream of the optical path of the light-emitting unit array, the microlens array comprising a plurality of microlenses, wherein each microlens corresponds to one of the light-emitting units and is configured to modulate a light beam emitted by the light-emitting unit corresponding thereto;

[0009] A collimating unit is disposed downstream of the optical path of the microlens array and is configured to shape the light beam modulated by the microlens array so that the fields of view formed by the light beams emitted from the collimating unit overlap or abut each other.

[0010] According to one aspect of the present invention, the light-emitting unit array includes a one-dimensional light-emitting unit array / a two-dimensional light-emitting unit array, wherein each light-emitting unit can be independently gated and addressed, and each of the light-emitting units includes a plurality of micro units that can emit light simultaneously.

[0011] According to one aspect of the present invention, the center of each microlens is aligned with the center of the light emitting surface of a corresponding light emitting unit.

[0012] According to one aspect of the present invention, the distance between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit is related to the parameters of the light emitting unit array.

[0013] According to one aspect of the present invention, the distance between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit is set so that each microlens only modulates the light beam emitted by the corresponding light emitting unit.

[0014] According to one aspect of the present invention, the parameters of the light emitting unit array include: the spacing between adjacent light emitting units, the size of each light emitting unit, and the divergence angle of the light beam emitted by each light emitting unit.

[0015] According to one aspect of the present invention, the distance between the center of each microlens and the center of the light-emitting surface of a corresponding light-emitting unit satisfies: d≤(pitch-a) / [2*tan(θ / 2)], wherein pitch is the spacing between adjacent light-emitting units along the first direction or the second direction, the first direction is perpendicular to the second direction, a is the size of each light-emitting unit along the first direction or the second direction, and θ is the divergence angle of the emitted light beam of each light-emitting unit along the first direction or the second direction.

[0016] According to one aspect of the present invention, the curved surfaces of adjacent microlenses in the microlens array are in contact with each other in a first direction and / or a second direction, and the first direction is perpendicular to the second direction.

[0017] According to one aspect of the present invention, the microlens array is integrated with the light emitting unit array, or the microlens array is packaged with the light emitting unit array via a packaging material.

[0018] According to one aspect of the present invention, the light emitting unit is of surface emitting type, and the light emitting unit array constitutes a vertical cavity surface emitting laser or a photonic crystal surface emitting laser.

[0019] The present invention also relates to a design method for a light emitting device for a laser radar, wherein the emitted light of the light emitting device is used to cover a detection area, and the design method comprises:

[0020] Determining parameters of a light emitting unit array, wherein the light emitting unit array comprises a plurality of light emitting units, the plurality of light emitting units are spaced apart from each other, wherein the emitted light of each light emitting unit is configured to cover a sub-area;

[0021] determining parameters of a collimating unit, the collimating unit being arranged downstream of the light path of the light emitting unit array; and

[0022] The parameters of the microlens array are determined according to the parameters of the light-emitting unit array, the parameters of the collimating unit and the detection area, wherein the microlens array is arranged between the light-emitting unit array and the collimating unit, and the microlens array includes a plurality of microlenses, each microlens corresponds to one of the light-emitting units, and is configured to modulate the light beam emitted by the light-emitting unit corresponding thereto, so that the fields of view formed by the light beams emitted from the collimating unit overlap or abut each other.

[0023] According to one aspect of the present invention, the parameters of the light emitting unit array include: the spacing between adjacent light emitting units, the size of each light emitting unit, and the divergence angle of the light beam emitted by each light emitting unit.

[0024] According to one aspect of the present invention, the light-emitting unit array includes a one-dimensional light-emitting unit array / a two-dimensional light-emitting unit array, wherein each light-emitting unit can be independently gated and addressed, and each of the light-emitting units includes a plurality of micro units that can emit light simultaneously.

[0025] According to one aspect of the present invention, the center of each microlens is aligned with the center of the light emitting surface of a corresponding light emitting unit.

[0026] According to one aspect of the present invention, the distance between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit is related to the parameters of the light emitting unit array.

[0027] According to one aspect of the present invention, it also includes: setting the distance between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit so that each microlens only modulates the light beam emitted by the corresponding light emitting unit.

[0028] According to one aspect of the present invention, the distance between the center of each microlens and the center of the light-emitting surface of a corresponding light-emitting unit satisfies: d≤(pitch-a) / [2*tan(θ / 2)], wherein pitch is the spacing between adjacent light-emitting units along the first direction or the second direction, the first direction is perpendicular to the second direction, a is the size of each light-emitting unit along the first direction or the second direction, and θ is the divergence angle of the output light beam of each light-emitting unit along the first direction or the second direction.

[0029] According to one aspect of the present invention, adjacent microlenses in the microlens array are in contact with each other in a first direction and / or a second direction, the first direction is perpendicular to the second direction, the light emitting unit is a surface emitting type, and the light emitting unit array constitutes a vertical cavity surface emitting laser or a photonic crystal surface emitting laser.

[0030] The present invention also relates to a laser radar, comprising:

[0031] The light emitting device as described above is configured to emit a detection light beam for detecting obstacles;

[0032] A detection device configured to respond to the echo reflected by the obstacle when the detection light beam is incident on the obstacle and convert it into an electrical signal; and

[0033] The processing device is coupled to the detection device and is configured to calculate obstacle information based on the electrical signal.

[0034] According to one aspect of the present invention, the detection device comprises a detection unit array, the detection unit array comprises a plurality of detection units, wherein each detection unit corresponds to one of the light emitting units of the light emitting device.

[0035] According to one aspect of the present invention, the laser radar comprises an all-solid-state laser radar.

[0036] In summary, the scheme of the present invention has been introduced in detail. The light emitting device of the present invention arranges a microlens array downstream of the optical path of the light-emitting unit. Each microlens can modulate the light beam emitted by the light-emitting unit corresponding thereto, so that the light beams emitted from multiple microlenses are shaped by the collimating unit to form fields that overlap or abut each other, thereby compensating for the partial field of view energy loss caused by the interval between adjacent light-emitting units, which is beneficial to improving the continuity of the field of view range and the uniformity of energy distribution.

[0037] Furthermore, the light emitting device of the present invention can be applied to laser radar. After the emission light beam of the light emitting unit is modulated by the microlens, it can be widened, amplified and / or homogenized to a certain extent, so as to form a field of view with more uniform energy distribution, stronger continuity and larger coverage. Accordingly, the signal-to-noise ratio of the echo signal can be improved, and at the same time, a larger detection range can be covered at the receiving end, which is beneficial to reduce the risk of target missed detection and improve the accuracy of the detection results.

[0038] Furthermore, the light emitting device of the present invention is applied to a laser radar, which can optimize the continuity and energy distribution uniformity of the field of view formed by the light beam emitted by a laser including a plurality of light-emitting units that can be driven separately, which is beneficial to further reduce target omissions and improve the accuracy of detection results.

[0039] Furthermore, the light emitting device of the present invention can be applied to an all-solid-state laser radar to form a field of view with more uniform energy distribution and greater continuity at the transmitting end, forming a planar light source with a higher coverage ratio or even full coverage. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0041] Figure 1 shows a schematic diagram of a light emitting unit array;

[0042] Figure 2 The field of view formed by the outgoing light beam of the existing light emitting device without a microlens array is shown;

[0043] Figure 3 A schematic diagram showing a light emitting device and a field of view formed by an outgoing light beam according to an embodiment of the present invention is shown;

[0044] Figure 4a and Figure 4b A schematic diagram of a microlens array according to a preferred embodiment of the present invention is shown;

[0045] Figure 5A schematic diagram showing that light beams emitted by adjacent light emitting units do not cause crosstalk in the horizontal direction according to a preferred embodiment of the present invention;

[0046] Figure 6 A schematic diagram showing crosstalk between light beams emitted by adjacent light emitting units in the horizontal direction according to a preferred embodiment of the present invention is shown;

[0047] Figure 7 A schematic diagram showing that light beams emitted by adjacent light emitting units do not cause crosstalk in the vertical direction according to a preferred embodiment of the present invention;

[0048] Figure 8 A schematic diagram showing crosstalk between light beams emitted by adjacent light-emitting units in the vertical direction according to a preferred embodiment of the present invention;

[0049] Fig. 9 A schematic diagram showing the contact of the curved surfaces of adjacent microlenses in the first direction or the second direction according to a preferred embodiment of the present invention;

[0050] Fig.10 A schematic diagram showing that the curved surfaces of adjacent microlenses in the first direction and the second direction do not touch each other according to a preferred embodiment of the present invention;

[0051] Fig.11 A schematic diagram showing the integration of a microlens array and a light emitting unit array according to a preferred embodiment of the present invention is shown;

[0052] Fig.12 A flow chart showing a method for designing a light emitting device according to an embodiment of the present invention is shown;

[0053] Fig.13 A schematic diagram of a laser radar according to an embodiment of the present invention is shown;

[0054] Fig.14a and Fig.14b Schematic diagrams showing energy distribution at the transmitting end and the receiving end when no microlens is provided downstream of the light path of the light emitting unit; and

[0055] Fig.15a and Fig.15b Schematic diagrams showing energy distribution at the transmitting end and the receiving end when a microlens is arranged downstream of the optical path of the light emitting unit according to a preferred embodiment of the present invention are shown respectively. DETAILED DESCRIPTION

[0056] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0057] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0058] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0060] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0061] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0062] The present invention provides a light emitting device for laser radar. Figure 3 FIG. 1 is a schematic diagram showing a light emitting device 10 and a field of view formed by an outgoing light beam according to an embodiment of the present invention. Figure 3 As shown, the light emitting device 10 includes a light emitting unit array 11, a microlens array 12 and a collimating unit 13, wherein the light emitting unit array 11 includes a plurality of light emitting units 111, the plurality of light emitting units 111 are spaced apart from each other, each light emitting unit 111 is configured to emit a light beam, the microlens array 12 is arranged downstream of the light path of the light emitting unit array 11, the microlens array 12 includes a plurality of microlenses 121, each microlens 121 corresponds to one of the light emitting units 111, and is configured to modulate the light beam emitted by the light emitting unit 111 corresponding thereto, the collimating unit 13 is arranged downstream of the light path of the microlens array 12, and is configured to shape the light beam L1 modulated by the microlens array 12, so that the fields of view formed by the light beam L2 emitted from the collimating unit 13 overlap or abut each other, each microlens can be configured to widen, amplify and / or homogenize the light beam emitted by the corresponding light emitting unit, so that the fields of view projected by each light emitting unit after being modulated by the microlens and then shaped by the collimating unit overlap or abut each other.

[0063] It should be noted that the adjacency mentioned here includes both close adjacency and adjacency with a small gap, as long as the gap is much smaller than that in the existing solution (refer to Figure 2 ) is sufficient as the gap between each field of view in a solution without a microlens array.

[0064] Preferably, the collimating unit 13 can adopt a collimating lens or a collimating lens group. The present invention does not limit the specific surface shape and number of the collimating lens. The parameters of the collimating unit 13 include the focal length of the lens. It can be understood by those skilled in the art that the field of view here refers to the far field of view (relative to the focal length of the lens). Generally, the laser radar is used to detect distances of more than several meters.

[0065] The light emitting device of the present invention arranges a microlens array downstream of the light path of the light emitting unit array, so that each microlens modulates the light beam emitted by the corresponding light emitting unit, so that the light beams emitted from multiple microlenses are shaped by the collimating unit and the fields of view formed overlap or abut each other, thereby Figure 2 The solution of the present invention can optimize the field of view interval problem formed by the emission light beams of adjacent light-emitting units, which is beneficial to improving the continuity of the field of view range and the uniformity of energy distribution. The light emitting device of the present invention is described in detail below.

[0066] In the light emitting device of the present invention, the light emitting unit array can be a one-dimensional light emitting unit array or a two-dimensional light emitting unit array, wherein each light emitting unit can be independently gated and addressed, and each light emitting unit can include a plurality of micro units that can emit light simultaneously. Preferably, each light emitting unit is a light emitting partition of the laser, and the partition wire bonding PAD of the laser (refer to Figure 1 The wire bonding PAD area shown in the shaded part is used to drive each light emitting unit respectively. The following is introduced by taking a two-dimensional light emitting unit array as an example. Those skilled in the art should understand that a one-dimensional light emitting unit array is similar to it, and will not be described here.

[0067] Figure 1 A schematic diagram of the light emitting unit array 11 is shown, Figure 1 As shown, the light emitting unit array 11 includes 3 rows and 4 columns, a total of 12 light emitting units, each light emitting unit constitutes a partition, and multiple partitions constitute the light emitting unit array. In the process design, due to the need for routing of regional drives, the drive lines of different partitions may need to be connected to different pads (refer to Figure 1 The wire bonding PAD area shown in the shaded part, the multiple partitions have a common substrate for example), so that the light emitting units 111 are arranged discontinuously, and there is an isolation area of ​​a certain size between adjacent light emitting units (gap area, see Figure 1 In order to optimize the field of view formed by the light beam emitted by the laser including a plurality of light-emitting units that can be driven separately, in the scheme of the present invention, preferably, the size of each light-emitting unit is the same, referring to Figure 1For example, the size of each light emitting unit in the horizontal direction is ax, and the size in the vertical direction is ay. Preferably, the spacing between adjacent light emitting units is the same, referring to Figure 1 For example, the center spacing of adjacent light-emitting units in the horizontal direction is pitch1, the center spacing in the vertical direction is pitch2, the edge spacing of adjacent light-emitting units in the horizontal direction is gap1, and the edge spacing in the vertical direction is gap2. In addition, the divergence angle of the emitted light beam of each light-emitting unit includes a divergence angle θx in the horizontal direction and a divergence angle θy in the vertical direction, refer to Figures 5 to 8 As shown. Figure 1 , each light-emitting unit 111 can be independently enabled and addressed, that is, each light-emitting unit 111 can be selected to be controlled individually. Among them, each light-emitting unit 111 (that is, each partition) can include multiple micro units 1110 that can emit light simultaneously. Preferably, each micro unit 1110 can also be independently enabled and addressed. It should be noted that although the present embodiment is introduced by taking the light-emitting unit array composed of 3*4 light-emitting units as an example, the present invention is not limited to this. In practical applications, the specific number and arrangement of the light-emitting units can be flexibly adjusted according to actual needs, which are all within the protection scope of the present invention.

[0068] In the light-emitting unit array of the present invention, the light-emitting unit can be a surface-emitting type, and the light-emitting unit array can constitute a vertical cavity surface-emitting laser (Vertical-Cavity Surface-Emitting Laser, VCSEL) or a photonic crystal surface-emitting laser (Photonic Crystal Surface Emitting Laser, PCSEL). When it is applied to a laser radar, the laser radar is preferably an all-solid-state laser radar, so as to form a field of view with higher continuity and more uniform energy distribution at the transmitting end. In addition, since the light-emitting unit array includes a plurality of light-emitting units, each light-emitting unit constitutes a partition, and each light-emitting unit can be independently gated and addressed, the laser radar can start one or more light-emitting units for local detection according to the detection requirements in actual detection, which is conducive to reducing power consumption and being more energy-saving and environmentally friendly.

[0069] The above embodiment introduces the light emitting unit array in the light emitting device of the present invention. The following introduces the microlens array in the light emitting device.

[0070] Figure 4a FIG. 4 shows a schematic plan view of a microlens array 12 according to a preferred embodiment of the present invention, Figure 4b FIG. 1 shows a three-dimensional schematic diagram of a microlens array 12 according to a preferred embodiment of the present invention. Figure 4a and Figure 4bIn this embodiment, the microlens array 12 includes 3 rows and 4 columns, a total of 12 microlenses. Preferably, the size of each microlens is the same. Figure 4a and Figure 4b For example, the size of each microlens in the horizontal direction is ax', and the size in the vertical direction is ay'. Preferably, the spacing between adjacent microlenses is the same, referring to Figure 4a and Figure 4b , for example, the center spacing of adjacent microlenses in the horizontal direction is pitch1', and the center spacing in the vertical direction is pitch2'. Preferably, the specific number of microlenses 12 in the microlens array 12 is equal to the number of light-emitting units 111 in the light-emitting unit array 11 and the arrangement method is the same. For example, the 12 light-emitting units 111 in the light-emitting unit array 11 are arranged in 3 rows and 4 columns, and accordingly, the 12 microlenses 121 in the microlens array 12 are also arranged in 3 rows and 4 columns. In addition, Figure 4b The embodiment shows that the curved surfaces of multiple microlenses in the microlens array are in contact with each other. Optionally, the curved surfaces of multiple microlenses in the microlens array may not be in contact with each other. It should be understood that this embodiment is only an exemplary description and does not constitute a limitation to the present invention.

[0071] In the light emitting device of the present invention, preferably, the center of each microlens is aligned with the center of the light emitting surface of a corresponding light emitting unit. Figure 5 As shown, for example, microlens 121 L The center O' and the corresponding light emitting unit 111 L The center O of the light emitting surface is aligned, that is, the line between the center O' and the center O is substantially perpendicular to the light emitting surface of the light emitting unit.

[0072] In the light emitting device of the present invention, the distance between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit is also called the back working distance.

[0073] In the light emitting device of the present invention, the distance between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit is related to the parameters of the light emitting unit array. The parameters of the light emitting unit array include the spacing between adjacent light emitting units, the size of each light emitting unit, and the divergence angle of the emitted light beam of each light emitting unit. The spacing, size, and divergence angle are related to the direction, including the spacing, size, and divergence angle along the first direction and the spacing, size, and divergence angle along the second direction. Preferably, the first direction may be the horizontal direction (or the vertical direction), and the second direction may be the vertical direction (or the horizontal direction). The first value of the distance may be first calculated according to the spacing, size, and divergence angle along the first direction, and then the second value of the distance may be calculated according to the spacing, size, and divergence angle along the second direction, and then the distance may be determined according to the first value and the second value.

[0074] Specifically, refer to Figure 5 , in a first direction (eg, horizontal direction), for example, microlens 121 L The center O' and the corresponding light emitting unit 111 L The distance dx between the center O of the light emitting surface and the light emitting unit 111 L The size of ax, light emitting unit 111 L and its adjacent light emitting unit 111 R The center distance pitch1 between the light emitting units 111 L For example, referring to Figure 7 In the second direction (vertical direction), the microlens 121 D The center O' and the corresponding light emitting unit 111 D The distance dy between the center O of the light emitting surface and the light emitting unit 111 D The size of the light emitting unit 111 D and its adjacent light emitting unit 111 U The center distance pitch2 between the light emitting units 111 D It is related to the vertical divergence angle θy of the emitted light beam.

[0075] The above embodiment introduces that the distance between the center of the microlens and the center of the light emitting surface of the corresponding light emitting unit is related to the parameters of the light emitting unit array. In the light emitting device of the present invention, the distance between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit is set so that each microlens only modulates the light beam emitted by the corresponding light emitting unit, thereby reducing the crosstalk between the light beams emitted by adjacent light emitting units. The following is a detailed description.

[0076] In order to make each microlens modulate only the light beam emitted by the corresponding light-emitting unit, the distance d between the center of each microlens and the center of the light-emitting surface of a corresponding light-emitting unit needs to meet the following condition (condition 1):

[0077] d≤(pitch-a) / [2*tan(θ / 2)]……(Condition 1)

[0078] Wherein, pitch is the spacing between adjacent light-emitting units along the first direction or the second direction, a is the size of each light-emitting unit along the first direction or the second direction, and θ is the divergence angle of the emitted light beam of each light-emitting unit along the first direction or the second direction. The following is an example in which the first direction is the horizontal direction and the second direction is the vertical direction.

[0079] First, the first direction (eg, horizontal direction) is introduced.

[0080] Reference Figure 5 , assuming that the light emitting unit 111 L The divergence angle of the emitted light beam in the horizontal direction is θx. To make 111 L and its adjacent light emitting unit 111 R In order for the emitted light beam to not cause crosstalk in the horizontal direction, (condition 2) must be met:

[0081] tan(θx / 2)≤(pitch1-ax) / [2*dx]……(Condition 2)

[0082] That is, the microlens 121 L The center O' and the corresponding light emitting unit 111 L The distance dx between the centers O of the light emitting surfaces needs to satisfy (condition 3):

[0083] dx≤(pitch1-ax) / [2*tan(θx / 2)]……(Condition 3)

[0084] Wherein, dx is the first value of the distance, pitch1 is the light emitting unit 111 L and its adjacent light emitting unit 111 R The center distance along the horizontal direction, ax is the light emitting unit 111 L The horizontal dimension of the light emitting unit 111 is θx. L The divergence angle of the emitted light beam along the horizontal direction.

[0085] On the contrary, when the microlens 121 L The center O' and the corresponding light emitting unit 111 L When the distance dx between the centers O of the light emitting surfaces does not satisfy the above (condition 3), that is, when dx>(pitch1-ax) / [2*tan(θx / 2)], the emission light beams of the adjacent light emitting units in the horizontal direction will crosstalk. Figure 6 As shown, the light emitting unit 111 on the left side in the horizontal direction L The emitted light beam will be transmitted to the right micro lens 121 R Top, right light unit 111 R The emitted light beam will be transmitted to the micro lens 121 on the left L superior.

[0086] Therefore, in order to prevent crosstalk between the light beams emitted by adjacent light-emitting units in the horizontal direction, the distance between the center of the microlens and the center of the light-emitting surface of the corresponding light-emitting unit must at least meet the above (condition 3).

[0087] The second direction (eg, vertical direction) is described below.

[0088] Reference Figure 7 , assuming that the light emitting unit 111 D The divergence angle of the emitted light beam in the vertical direction is θy. To make the light emitting unit 111 D and its adjacent light emitting unit 111 U If the emitted light beam does not crosstalk in the vertical direction, then (condition 4) must be met:

[0089] tan(θy / 2)≤(pitch2-ay) / [(2*dy)]……(Condition 4)

[0090] That is, the microlens 121 D The center O' and the corresponding light emitting unit 111 D The distance dy between the centers O of the light-emitting surfaces satisfies (condition 5):

[0091] dy≤(pitch2-ay) / [2*tan(θy / 2)]......(Condition 5)

[0092] Wherein, dy is the second value of the distance, pitch2 is the light emitting unit 111 D and its adjacent light emitting unit 111 U The center distance along the vertical direction, ay is the distance between the light emitting units 111 D The vertical dimension of the light emitting unit 111 is θy. D The divergence angle of the emitted light beam in the vertical direction.

[0093] On the contrary, when the microlens 121 D The center O' and the corresponding light emitting unit 111 D When the distance dy between the centers O of the light emitting surfaces does not satisfy the above (condition 5), that is, when dy>(pitch2-ay) / [2*tan(θy / 2)], the emitted light beams of the adjacent light emitting units in the vertical direction will crosstalk. Figure 8 , vertically upward light emitting unit 111 U The emitted light beam will be transmitted to the micro lens 121 below D Upper and lower light emitting units 111 D The emitted light beam will be transmitted to the upper microlens 121 U superior.

[0094] Therefore, in order to prevent crosstalk between the emitted light beams of adjacent light-emitting units in the vertical direction, the distance between the center of the microlens and the center of the light-emitting surface of the corresponding light-emitting unit must at least meet the above (condition 5).

[0095] Furthermore, in order to prevent crosstalk between the light beams emitted by adjacent light-emitting units in the horizontal and vertical directions, (Condition 6) needs to be met:

[0096] d≤min{dx,dy}……(Condition 6)

[0097] Wherein, d is the distance between the center O' of the microlens and the center O of the light-emitting surface of the corresponding light-emitting unit, dx is the distance between the center of the microlens corresponding to the light beams emitted by adjacent light-emitting units in the horizontal direction without crosstalk and the center of the light-emitting surface of the corresponding light-emitting unit, and dy is the distance between the center of the microlens corresponding to the light beams emitted by adjacent light-emitting units in the vertical direction without crosstalk and the center of the light-emitting surface of the corresponding light-emitting unit.

[0098] On the contrary, when the distance d between the center O' of the microlens and the center O of the light emitting surface of the corresponding light emitting unit does not satisfy the above (condition 6), that is, when d>min{dx,dy}, the emission light beams of adjacent light emitting units in the horizontal direction and / or vertical direction will crosstalk.

[0099] The above embodiments introduce in detail the conditions (conditions 1, 3, 5 and 6) that need to be satisfied for the distance between the center of each microlens and the center of the light-emitting surface of a corresponding light-emitting unit. The setting of the distance between the center of each microlens and the center of the light-emitting surface of a corresponding light-emitting unit enables each microlens to modulate only the light beam emitted by the light-emitting unit corresponding to it, thereby reducing the crosstalk between the light beams emitted by adjacent light-emitting units. When applied to a laser radar, it is beneficial to improve the accuracy of the detection results.

[0100] In the light emitting device of the present invention, the distance between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit is set so that the curved surfaces of adjacent microlenses in the microlens array in the first direction and / or the second direction are in contact. Figure 4b The figure shows the situation where the curved surfaces of adjacent microlenses in the microlens array in the first direction and the second direction are in contact with each other. Fig. 9 The figure shows the situation where the curved surfaces of adjacent microlenses in the microlens array are in contact with each other in the first direction or the second direction. Fig.10 The figure shows a situation where the curved surfaces of adjacent microlenses in the microlens array do not touch each other in the first direction and the second direction.

[0101] In some preferred embodiments of the present invention, the divergence angle of the light emitting unit in the horizontal direction is equal to the divergence angle in the vertical direction, and both are described as θ below. Figure 1 , Figure 4a and Figure 4bSince the center of each microlens is aligned with the center of the light emitting surface of a corresponding light emitting unit, the center spacing pitch1 of adjacent light emitting units in the horizontal direction is equal to the center spacing pitch1' of adjacent microlenses in the horizontal direction, that is, pitch1=pitch1', and the center spacing pitch2 of adjacent light emitting units in the vertical direction is equal to the center spacing pitch2' of adjacent microlenses in the vertical direction, that is, pitch2=pitch2'.

[0102] Method 1:

[0103] When the distance d between the center of the microlens and the center of the light emitting surface of the corresponding light emitting unit is d=dx=dy, the size of the microlens in the horizontal direction is ax'=pitch1'=pitch1, and the size in the vertical direction is ay'=pitch2'=pitch2. At this time, the curved surfaces of adjacent microlenses in the microlens array in the first direction (e.g., X direction or Y direction) and the second direction (e.g., Y direction or X direction) are in contact, refer to Figure 4b The situation shown.

[0104] Method 2:

[0105] When the distance d between the center of the microlens and the center of the light emitting surface of the corresponding light emitting unit is d=dx<dy, the size of the microlens in the horizontal direction is ax'=pitch1'=pitch1, and the size in the vertical direction is ay'=2d*tan(θ / 2)+ay, that is, ay'=2dx*tan(θ / 2)+ay. At this time, ay'<pitch2', the curved surfaces of adjacent microlenses in the microlens array are in contact in the first direction (e.g., X direction, horizontal direction), and are not in contact in the second direction (e.g., Y direction, vertical direction). Fig. 9 The situation shown.

[0106] Method 3:

[0107] Although not shown in the figure, similarly, when the distance d=dy<dx between the center of the microlens and the center of the light emitting surface of the corresponding light emitting unit, the size of the microlens in the horizontal direction is ax'=2d*tan(θ / 2)+ax, that is, ax'=2dy*tan(θ / 2)+ax, and the size in the vertical direction is ay'=pitch2'=pitch2. At this time, ax'<pitch1', and the curved surfaces of adjacent microlenses in the microlens array are in contact in the second direction (for example, the Y direction, the vertical direction), and are not in contact in the first direction (for example, the X direction, the horizontal direction).

[0108] Method 4:

[0109] Similarly, when the distance between the center of the microlens and the center of the light-emitting surface of the corresponding light-emitting unit is d<dx<dy, the size of the microlens in the horizontal direction is ax'=2d*tan(θ / 2)+ax, and the size in the vertical direction is ay'=2d*tan(θ / 2)+ay. At this time, ax'<pitch1', ay'<pitch2', and the curved surfaces of adjacent microlenses in the microlens array in the first direction (for example, the X direction) and the second direction (for example, the Y direction) do not touch each other. Fig.10 The situation shown.

[0110] The above embodiments introduce several ways of setting the distance between the center of a microlens and the center of a light-emitting surface of a corresponding light-emitting unit. In the actual design process, it is preferably set to the above-mentioned way 1 so that the curved surfaces of adjacent microlenses in the microlens array in the first direction and the second direction are in contact, which is beneficial to reduce the crosstalk between the emission light beams of adjacent light-emitting units and reduce the processing difficulty of the microlens array.

[0111] According to a preferred embodiment of the present invention, referring to Fig.11 , the microlens array 12 can be integrated with the light emitting unit array 11. According to another preferred embodiment of the present invention, the microlens array 12 can also be packaged with the light emitting unit array 11 through a packaging material (not shown in the figure). Optionally, the microlens array 12 can be integrated on, for example, a glass sheet at the exit of the packaging shell of the laser formed by the light emitting unit array 11, but the present invention is not limited thereto, and the specific material of the packaging material and the packaging position can be set according to actual conditions.

[0112] Those skilled in the art should understand that in the actual design of the light emitting device, the curvature radius and thickness of the microlens and the focal length of the lens of the collimating unit should also be considered. The specific curvature radius, thickness and focal length of the lens can be optimized by optical simulation based on the required field of view and the difficulty of surface processing, so that the light beams emitted from multiple microlenses form overlapping or adjacent fields of view after being collimated by the collimating unit.

[0113] The light emitting device of the present invention is introduced above. The light emitting device of the present invention arranges a microlens array downstream of the optical path of the light emitting unit. Each microlens can modulate the light beam emitted by the light emitting unit corresponding to it, so that the fields of view formed by the light beams emitted from multiple microlenses after being shaped by the collimating unit overlap or abut each other, thereby compensating for the partial field of view energy loss caused by the interval between adjacent light emitting units, which is beneficial to improving the continuity of the field of view range and the uniformity of energy distribution.

[0114] The present invention also relates to a design method for a light emitting device for a laser radar, wherein the emitted light of the light emitting device is used to cover a detection area, and the light emitting device includes the light emitting device as described above.

[0115] Fig.12 A flow chart of a design method 300 according to an embodiment of the present invention is shown. Figure 1 , Figures 3 to 12 The design method 300 includes steps S310 to S330. In step S310, the parameters of the light-emitting unit array 11 are determined, wherein the light-emitting unit array 11 includes a plurality of light-emitting units 111, and the plurality of light-emitting units 111 are spaced apart from each other, wherein the emitted light of each light-emitting unit 111 is configured to cover a sub-area; in step S320, the parameters of the collimating unit 13 are determined, and the collimating unit 13 is arranged downstream of the optical path of the light-emitting unit array 11; in step S330, the parameters of the microlens array 12 are determined according to the parameters of the light-emitting unit array 11, the parameters of the collimating unit 13, and the detection area, wherein the microlens array 12 is arranged between the light-emitting unit array 11 and the collimating unit 13, and the microlens array 12 includes a plurality of microlenses 121, each microlens 121 corresponds to one of the light-emitting units 111, and is configured to modulate the light beam emitted by the light-emitting unit 111 corresponding thereto, so that the fields of view formed by the light beams L2 emitted from the collimating unit 13 overlap or abut each other.

[0116] According to a preferred embodiment of the present invention, the parameters of the light emitting unit array 11 include: the spacing between adjacent light emitting units, the size of each light emitting unit, and the divergence angle of the light beam emitted by each light emitting unit.

[0117] According to a preferred embodiment of the present invention, the light emitting unit array 11 includes a one-dimensional light emitting unit array / a two-dimensional light emitting unit array, wherein each light emitting unit can be independently gated and addressed, and each light emitting unit includes a plurality of micro units that can emit light simultaneously.

[0118] According to a preferred embodiment of the present invention, the center O' of each microlens is aligned with the center O of the light emitting surface of a corresponding light emitting unit.

[0119] According to a preferred embodiment of the present invention, the distance between the center O′ of each microlens and the center O of the light emitting surface of a corresponding light emitting unit is related to the parameters of the light emitting unit array 11 .

[0120] According to a preferred embodiment of the present invention, the design method 300 further includes: setting the distance between the center O' of each microlens and the center O of the light emitting surface of a corresponding light emitting unit so that each microlens only modulates the light beam emitted by the corresponding light emitting unit.

[0121] According to a preferred embodiment of the present invention, the distance d between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit satisfies: d≤(pitch-a) / [2*tan(θ / 2)], wherein pitch is the spacing between adjacent light emitting units along the first direction or the second direction, the first direction is perpendicular to the second direction, a is the size of each light emitting unit along the first direction or the second direction, and θ is the divergence angle of the output light beam of each light emitting unit along the first direction or the second direction.

[0122] According to a preferred embodiment of the present invention, adjacent microlenses in the microlens array are in contact with each other at curved surfaces in a first direction and / or a second direction, the light-emitting unit is a surface-emitting type, and the light-emitting unit array constitutes a vertical-cavity surface-emitting laser (VCSEL) or a photonic crystal surface-emitting laser (PCSEL).

[0123] The design method 300 of the present invention is introduced above. In addition, the present invention also provides a laser radar. Fig.13 FIG. 4 shows a schematic diagram of a laser radar 500 according to an embodiment of the present invention. Fig.13 As shown, the laser radar 500 includes the light emitting device 10, the detection device 520 and the processing device 530 as described above, wherein the light emitting device 10 is configured to emit a detection light beam Light for detecting an obstacle OB; the detection device 520 is configured to respond to the echo Light' reflected by the detection light beam Light incident on the obstacle OB and convert it into an electrical signal; the processing device 530 is coupled to the detection device 520 and configured to calculate the obstacle information based on the electrical signal.

[0124] According to a preferred embodiment of the present invention, the detection device 520 includes a detection unit array, which includes a plurality of detection units 521 (one of the detection units is exemplarily shown in the figure), each detection unit 521 can be used as a region, and each detection unit 521 corresponds to one of the light-emitting units 111 of the light-emitting device 10. Preferably, the plurality of detection units 521 can be arranged as a one-dimensional linear array or a two-dimensional surface array. Preferably, each detection unit 521 includes a plurality of pixels (not shown in the figure), and each pixel can include at least one single photon avalanche diode (SPAD).

[0125] According to a preferred embodiment of the present invention, the laser radar 500 may be a fully solid-state laser radar, forming a fully covered array light source. In addition, the laser radar 500 may also be a scanning laser radar or a mechanical rotating laser radar.

[0126] Fig.14a shows the energy distribution at the emission end when no microlens is provided downstream of the light path of the light emitting unit, Fig.14b shows the energy distribution at the receiving end when no microlens is set downstream of the light path of the light emitting unit. Fig.14a It can be seen that the micro units 1110 in the light emitting unit 111 are relatively discrete, and the light energy emitted by each micro unit 1110 is not homogenized, with high energy in the middle and low energy in the periphery, resulting in uneven energy distribution in the field of view formed by the light beam emitted by the entire light emitting unit 111. Fig.14b As shown, the echo energy received by the detection unit 521 corresponding to the light-emitting unit 111 is also unevenly distributed, thereby affecting the signal-to-noise ratio and the accuracy of the detection result.

[0127] Fig.15a shows the energy distribution at the emission end when a microlens is provided downstream of the light path of the light emitting unit, Fig.15b shows the energy distribution at the receiving end when a microlens is provided downstream of the light path of the light emitting unit. Fig.15a It can be seen that the emitted light of each micro-unit 1110 in the light-emitting unit 111 is homogenized by the micro-lens, and the energy distribution of the emitted light of each micro-unit 1110 is more uniform after being emitted by the micro-lens, so that the energy distribution within the field of view formed by the emitted light beam of the entire light-emitting unit 111 after being emitted by the micro-lens is more uniform. Fig.15b , the distribution of the echo energy received by the detection unit 521 corresponding to the light-emitting unit 111 is also more uniform, which is beneficial to improving the signal-to-noise ratio of the echo signal and improving the accuracy of the detection result. In addition, after the emission light beam of the light-emitting unit 111 is modulated by the microlens, the field of view formed after it is emitted from the microlens can be widened and magnified to a certain extent, thereby reducing the gap between the field of view areas corresponding to the adjacent light-emitting units, so that the coverage area of ​​the echo energy in the detection unit 521 can be further increased, which is beneficial to reducing the possibility of missing the target and further improving the accuracy of the detection result.

[0128] The present invention also provides a computer-readable storage medium, comprising computer-executable instructions stored thereon, which implement the operation of the laser radar as described above when executed by a processor.

[0129] In some preferred embodiments, the computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it. The computer-readable storage medium can adopt any combination of one or more computer-readable media. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, or semiconductor form or device, and more specific examples (non-exhaustive list) include: an electrical connection with one or more wires, a portable computer hard disk, a hard disk, a random access memory (RAM), a non-volatile random access memory (NVRAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0130] In addition, the present invention also provides a computer device (not shown in the figure), including a memory and a processor, wherein the memory is configured to store computer executable instructions, and the executable instructions implement the operation of the laser radar as described above when executed by the processor.

[0131] In some preferred embodiments of the present invention, the processor / processing device may include a central processing unit (CPU), and may also include other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The present invention is not limited to this and it depends on the specific circumstances.

[0132] In summary, the scheme of the present invention has been introduced in detail. The light emitting device of the present invention arranges a microlens array downstream of the optical path of the light-emitting unit. Each microlens can modulate the light beam emitted by the light-emitting unit corresponding thereto, so that the light beams emitted from multiple microlenses are shaped by the collimating unit to form fields that overlap or abut each other, thereby compensating for the partial field of view energy loss caused by the interval between adjacent light-emitting units, which is beneficial to improving the continuity of the field of view and the uniformity of energy distribution.

[0133] Furthermore, the light emitting device of the present invention can be applied to laser radar. After the emission light beam of the light emitting unit is modulated by the microlens, it can be widened, amplified and / or homogenized to a certain extent, so as to form a field of view with more uniform energy distribution, stronger continuity and larger coverage. Accordingly, the signal-to-noise ratio of the echo signal can be improved, and at the same time, a larger detection range can be covered at the receiving end, which is beneficial to reduce the risk of target missed detection and improve the accuracy of the detection results.

[0134] Furthermore, the light emitting device of the present invention is applied to a laser radar, which can optimize the continuity and energy distribution uniformity of the field of view formed by the light beam emitted by a laser including a plurality of light-emitting units that can be driven separately, which is beneficial to further reduce target omissions and improve the accuracy of detection results.

[0135] Furthermore, the light emitting device of the present invention can be applied to an all-solid-state laser radar to form a field of view with more uniform energy distribution and greater continuity at the transmitting end, forming a planar light source with a higher coverage ratio or even full coverage.

[0136] It should be noted that, although the light emitting device and several modules or submodules of the laser radar are mentioned in the above detailed description, this division is not mandatory. In fact, according to an embodiment of the present invention, the features and functions of two or more modules described above can be implemented in one module. Conversely, the features and functions of one module described above can be further divided into multiple modules to be concretized.

[0137] It should be noted that this specification provides method operation steps as described in the embodiments or schematic diagrams, but more or fewer operation steps may be included based on conventional or non-creative labor. The order of steps listed in the embodiments is only one way of executing the order of many steps and does not represent the only execution order. When the actual system or device product is executed, it can be executed in the order or in parallel according to the method shown in the embodiments or flowcharts.

[0138] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A light emitting device for laser radar, comprising: a light emitting unit array, the light emitting unit array comprising a plurality of light emitting units, wherein the plurality of light emitting units are spaced apart from each other, and each light emitting unit is configured to emit a light beam; a microlens array, the microlens array being arranged downstream of the optical path of the light-emitting unit array, the microlens array comprising a plurality of microlenses, wherein each microlens corresponds to one of the light-emitting units and is configured to modulate a light beam emitted by the light-emitting unit corresponding thereto; and A collimating unit is disposed downstream of the optical path of the microlens array and is configured to shape the light beam modulated by the microlens array so that the fields of view formed by the light beams emitted from the collimating unit overlap or abut each other.

2. The light emitting device according to claim 1, wherein the light emitting unit array comprises a one-dimensional light emitting unit array / a two-dimensional light emitting unit array, wherein each light emitting unit can be independently selected and addressed, and each of the light emitting units comprises a plurality of micro units that can emit light simultaneously. 3 . The light emitting device according to claim 1 , wherein the center of each microlens is aligned with the center of the light emitting surface of a corresponding light emitting unit. 4 . The light emitting device according to claim 3 , wherein the distance between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit is related to the parameters of the light emitting unit array.

5. The light emitting device according to claim 3, wherein the distance between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit is set so that each microlens only modulates the light beam emitted by the corresponding light emitting unit.

6. The light emitting device according to claim 3, wherein the parameters of the light emitting unit array include: The spacing between adjacent light-emitting units, the size of each light-emitting unit, and the divergence angle of the emitted light beam of each light-emitting unit.

7. The light emitting device according to claim 5, wherein the distance d between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit satisfies: d≤(pitch-a) / [2*tan(θ / 2)], wherein, pitch is the spacing between adjacent light emitting units along the first direction or the second direction, the first direction is perpendicular to the second direction, a is the size of each light emitting unit along the first direction or the second direction, and θ is the divergence angle of the emitted light beam of each light emitting unit along the first direction or the second direction. 8 . The light emitting device according to claim 1 , wherein curved surfaces of adjacent microlenses in the microlens array are in contact with each other in a first direction and / or a second direction, and the first direction is perpendicular to the second direction. 9 . The light emitting device according to claim 1 , wherein the microlens array is integrated with the light emitting unit array, or the microlens array is packaged with the light emitting unit array via a packaging material. 10 . The light emitting device according to claim 1 , wherein the light emitting unit is a surface emitting type, and the light emitting unit array constitutes a vertical cavity surface emitting laser or a photonic crystal surface emitting laser.

11. A design method for a light emitting device for a laser radar, wherein the emitted light of the light emitting device is used to cover a detection area, the design method comprising: Determining parameters of a light emitting unit array, wherein the light emitting unit array comprises a plurality of light emitting units, the plurality of light emitting units are spaced apart from each other, wherein the emitted light of each light emitting unit is configured to cover a sub-area; Determining parameters of a collimating unit, wherein the collimating unit is arranged downstream of the light path of the light emitting unit array; and The parameters of the microlens array are determined according to the parameters of the light-emitting unit array, the parameters of the collimating unit and the detection area, wherein the microlens array is arranged between the light-emitting unit array and the collimating unit, and the microlens array includes a plurality of microlenses, each microlens corresponds to one of the light-emitting units, and is configured to modulate the light beam emitted by the light-emitting unit corresponding thereto so that the fields of view formed by the light beams emitted from the collimating unit overlap or abut each other.

12. The design method according to claim 11, wherein the parameters of the light emitting unit array include: The spacing between adjacent light-emitting units, the size of each light-emitting unit, and the divergence angle of the emitted light beam of each light-emitting unit.

13. The design method according to claim 11 or 12, wherein the light-emitting unit array comprises a one-dimensional light-emitting unit array / a two-dimensional light-emitting unit array, wherein each light-emitting unit can be independently selected and addressed, and each of the light-emitting units comprises a plurality of micro units that can emit light simultaneously. 14 . The design method according to claim 13 , wherein the center of each microlens is aligned with the center of the light emitting surface of a corresponding light emitting unit. 15 . The design method according to claim 14 , wherein the distance between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit is related to the parameters of the light emitting unit array.

16. The design method according to claim 14, further comprising: The distance between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit is set so that each microlens only modulates the light beam emitted by the corresponding light emitting unit.

17. The design method according to claim 16, wherein the distance d between the center of each microlens and the center of the light emitting surface of a corresponding light emitting unit satisfies: d≤(pitch-a) / [2*tan(θ / 2)], wherein, pitch is the spacing between adjacent light emitting units along the first direction or the second direction, the first direction is perpendicular to the second direction, a is the size of each light emitting unit along the first direction or the second direction, and θ is the divergence angle of the output light beam of each light emitting unit along the first direction or the second direction.

18. The design method according to claim 11 or 12, wherein adjacent microlenses in the microlens array are in contact with each other at curved surfaces in a first direction and / or a second direction, the first direction is perpendicular to the second direction, the light-emitting unit is a surface-emitting type, and the light-emitting unit array constitutes a vertical cavity surface-emitting laser or a photonic crystal surface-emitting laser.

19. A laser radar, comprising: The light emitting device according to any one of claims 1 to 10, configured to emit a detection light beam for detecting obstacles; A detection device configured to respond to the echo reflected by the obstacle when the detection light beam is incident on the obstacle and convert it into an electrical signal; and The processing device is coupled to the detection device and is configured to calculate obstacle information based on the electrical signal.

20. The laser radar according to claim 19, wherein the detection device comprises a detection unit array, the detection unit array comprises a plurality of detection units, wherein each detection unit corresponds to one of the light-emitting units of the light-emitting device.

21. A laser radar according to claim 19 or 20, wherein the laser radar comprises an all-solid-state laser radar.

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