Optical module, light emitter, laser radar and vehicle

Abstract

The invention discloses an optical module, a light emitter, a laser radar and a vehicle. According to the optical module, the focal power of a first lens is a positive value, the object side face of the first lens is a concave face, the image side face of the first lens is a convex face, and the first lens is configured to receive an incident beam; the focal power of the second lens is a positive value, and the object side surface and the image side surface of the second lens are convex surfaces; the focal power of the third lens is a positive value, and the object side surface and the image side surface of the third lens are convex surfaces; the focal power of the fourth lens is a negative value, the object side surface of the fourth lens is a concave surface, and the image side surface is a convex surface; the focal power of the fifth lens is a negative value, the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a convex surface; the first lens, the second lens, the third lens, the fourth lens and the fifth lens are sequentially arranged in the light emitting direction. The optical module meets the following relational expressions that d1 / TTL is larger than or equal to 0.15 and smaller than or equal to 0.22; wherein d1 is the distance from the image side surface of the fourth lens to the object side surface of the fifth lens on the optical axis, and TTL is the total optical length of the optical module.

Description

Technical Field

[0001] This invention relates to the field of lidar technology, and particularly to an optical module, a light emitter, lidar, and a vehicle. Background Technology

[0002] To achieve a wide field of view and a collimated beam with lower beam divergence, lidar systems often use optical systems with a larger number of lenses. However, the more lenses there are, the higher the manufacturing precision and material quality required, which in turn increases the cost of the optical system. Furthermore, the increase in the number of lenses also affects the size and weight of the optical system, which seriously hinders the miniaturization of optical lenses.

[0003] Therefore, how to balance the collimation angle of the emitted beam, the field of view (FOV), and the miniaturization of the optical lens in the optical system of lidar is a problem that urgently needs to be solved in this field. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide an optical module, a light emitter, a lidar, and a vehicle, which can solve at least one of the above-mentioned technical problems.

[0005] In a first aspect, embodiments of the present invention provide an optical module, the optical module comprising:

[0006] A first lens, wherein the optical power of the first lens is positive, the object side of the first lens is concave and the image side is convex, and the first lens is configured to receive an incident light beam.

[0007] The second lens has a positive optical power, and both its object-side and image-side surfaces are convex.

[0008] The third lens has a positive optical power, and both its object-side and image-side surfaces are convex.

[0009] The fourth lens has a negative optical power, and its object side is concave while its image side is convex.

[0010] The fifth lens has a negative optical power, and its object side is concave while its image side is convex.

[0011] The first lens, the second lens, the third lens, the fourth lens, and the fifth lens are arranged sequentially along the light emission direction, and the optical module satisfies the following relationship:

[0012] 0.15≤d1 / TTL≤0.22;

[0013] Wherein, d1 is the distance on the optical axis from the image side of the fourth lens to the object side of the fifth lens, and TTL is the total optical length of the optical module.

[0014] In a second aspect, embodiments of the present invention provide an optical emitter, comprising:

[0015] The optical module described in any of the above embodiments; and

[0016] A light-emitting chip is disposed on the object side of the first lens.

[0017] Thirdly, embodiments of the present invention provide a lidar, comprising:

[0018] The light emitter described in any of the above embodiments; and

[0019] Optical receiver.

[0020] Fourthly, embodiments of the present invention provide a vehicle, comprising:

[0021] The lidar described in any of the above embodiments.

[0022] This invention discloses an optical module, a light emitter, a lidar, and a vehicle, comprising: a first lens with positive optical power, a concave object-side surface and a convex image-side surface, configured to receive an incident light beam; a second lens with positive optical power, both its object-side and image-side surfaces being convex; a third lens with positive optical power, both its object-side and image-side surfaces being convex; a fourth lens with negative optical power, a concave object-side surface and a convex image-side surface; and a fifth lens with negative optical power, a concave object-side surface and a convex image-side surface. The first, second, third, fourth, and fifth lenses are arranged sequentially along the light emission direction, and the optical module satisfies the following relationship: 0.15 ≤ d1 / TTL ≤ 0.22; where d1 is the distance on the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens, and TTL is the total optical length of the optical module.

[0023] By setting the first, second, and third lenses as positive power lenses, it is beneficial for light convergence. Even if the emitting position of the emitting surface is far from the optical axis, the emitted beam from the edge emitting unit can be smoothly bent towards the central optical axis, allowing the converged light to smoothly enter the fourth lens. The fourth and fifth lenses are negative power lenses, which are beneficial for light divergence. They deflect the incident beam after passing through the first, second, and third lenses away from the central optical axis, expanding the field of view of the outgoing beam. This allows the outgoing beam to exit with a large field of view and a wide angle of exit, and also allows for uniform light emission in the X and Y directions. In addition to beam divergence, the fourth lens also has a light transition function. After receiving the incident beam bent by the third lens, the fourth lens can make the incident beam smoothly enter the fifth lens. The smooth propagation of the beam between the first, second, third, fourth and fifth lenses helps to reduce the manufacturing cost of the lenses. By constraining 0.15≤d1 / TTL≤0.22, it is beneficial to reasonably allocate the air gap between the fourth and fifth lenses, reduce the total optical length, and also ensure the size design of the external structural components, avoiding the structural components being too small or too long.

[0024] In other words, by setting five lenses and optimizing the optical power of each lens and constraining the lens spacing, this application enables the collimated beam emitted from the optical module provided in this application to have high collimation and a large field of view and wide angle. It also achieves a short lens length and a small lens aperture, thereby balancing the collimation angle of the emitted beam, FOV, and miniaturization of the optical lens.

[0025] Additional aspects and advantages of embodiments of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0027] Figure 1 This is a schematic diagram illustrating the application scenario of the lidar of the present invention in a vehicle;

[0028] Figure 2 This is a schematic diagram of the optical module structure in the first embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the shape of the F-theta distortion curve according to the first embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the optical module structure in the second embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the shape of the F-theta distortion curve according to the second embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the optical module structure in the third embodiment of the present invention;

[0033] Figure 7 This is a schematic diagram of the shape of the F-theta distortion curve according to the third embodiment of the present invention;

[0034] Figure 8 This is a schematic diagram of the optical module structure in the fourth embodiment of the present invention;

[0035] Figure 9 This is a schematic diagram of the shape of the F-theta distortion curve according to the fourth embodiment of the present invention. Detailed Implementation

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0037] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0038] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0039] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0040] First, before detailing the embodiments of this disclosure, the relevant technology will be further introduced.

[0041] LiDAR, acting as the "eyes" of intelligent vehicle driving, plays an irreplaceable role in realizing vehicle intelligence. Wide-field-of-view (FOV) lidar provides vehicles with point cloud construction of their surrounding environment at medium to close ranges, as well as the ability to perceive and identify targets. To enable vehicles to acquire information more accurately, the lidar's transmitting lens needs to collimate the emitted beam into a collimated beam with lower divergence, thus achieving projection over longer distances.

[0042] In order to achieve a large field of view and wide-angle projection beam, as well as a collimated beam with lower beam divergence, optical systems with more lenses are often chosen. However, the more lenses there are, the higher the manufacturing precision and material quality required, which leads to an increase in the cost of the optical system. Furthermore, the increase in the number of lenses will also affect the size and weight of the optical system, which will seriously affect the miniaturization of optical lenses.

[0043] Therefore, how to balance the collimation angle of the emitted beam, the field of view (FOV), and the miniaturization of the optical lens in an optical system is a problem that urgently needs to be solved in this field.

[0044] In view of this, this application proposes an optical module 10, a light emitter, and a lidar 100. The optical module can be used as the light emitter of the lidar, and the lidar can be used in vehicles. Please refer to [link to relevant documentation]. Figure 1 , Figure 1 This diagram illustrates an application scenario for LiDAR, which includes an optical module, in vehicles.

[0045] This application proposes a lidar 100 according to an embodiment. The lidar 100 includes a light emitter and a light receiver. The light beam emitted by the light emitter is directed toward an object and reflected off the surface of the object. The light beam reflected by the object returns to the lidar 100 and is received by the light receiver. By analyzing the light beam, the object can be identified and measured.

[0046] Please see Figure 2 The light emitter includes an optical module 10 and a light-emitting chip. The light-emitting chip is located on the object side of the first lens E11. The light emitted by the light-emitting chip is modulated by the optical module 10 and then directed toward the object.

[0047] Optionally, the light-emitting chip includes at least one of an area array light-emitting chip, a linear array light-emitting chip, and a pulsed laser.

[0048] Among them, the light-emitting chip can be an electronic component that emits a laser beam with pulse intervals after electro-optic conversion.

[0049] Optionally, the divergence angle of the laser beam emitted by the light-emitting chip is 2*asin(NA), where NA is the numerical aperture.

[0050] Among them, the area light-emitting chip can be a vertical cavity surface-emitting laser (VCSEL), an area array LED chip, a quantum dot array, etc.; for example, the linear light-emitting chip can be an edge-emitting laser array, a linear LED array, a fiber laser array, etc.; for example, the pulsed laser can be a pulsed diode laser, a Q-switched solid-state laser, a pulsed fiber laser, etc.

[0051] For example, the light-emitting chip may include an area array light-emitting chip; or, the light-emitting chip may include an area array light-emitting chip and a linear array light-emitting chip; or, the light-emitting chip may include a pulsed laser. This application does not limit these possibilities and will not describe them one by one here.

[0052] Optionally, the light-emitting chip includes multiple light-emitting units, which are arranged horizontally and vertically to form a matrix structure, forming a light-emitting surface L10. The area array light-emitting chip or the linear array light-emitting chip includes an array of optical fibers or a linear array of optical fibers arranged at intervals in the horizontal and vertical directions. The optical fiber array or the linear array of optical fibers includes multiple optical fiber lasers, and the laser beam emitted by a single optical fiber has a divergence angle of 2*asin(NA).

[0053] For ease of explanation, we will take the direction of beam propagation as the Z direction, the longitudinal direction of multiple light-emitting units arranged horizontally and vertically as the X direction, the transverse direction as the Y direction, and the optical axis as oo' as an example.

[0054] Please see Figure 2 The optical module 10 includes a first lens E11, a second lens E12, a third lens E13, a fourth lens E14, and a fifth lens E15. The light-emitting surface L10 of the light-emitting unit and the object-facing surface of the first lens E11 are arranged opposite each other. The first lens E11, the second lens E12, the third lens E13, the fourth lens E14, and the fifth lens E15 are arranged sequentially along the light emission direction.

[0055] The first lens E11 has a positive optical power, the object side S10 of the first lens E11 is concave, the image side S11 of the first lens E11 is convex, and the first lens E11 is configured to receive the incident light beam.

[0056] The object-side surface S10 of the first lens E11 and the light-emitting surface L10 of the light-emitting chip are positioned opposite each other to receive incident light. The positive optical power causes the first lens E11 to converge the incident light beam, reducing the divergence angle of the incident light beam in the X and Y directions. The object-side surface S10 of the first lens E11 is concave, and the image-side surface S11 is convex. The concave structure causes the incident light beam to diverge to a certain extent first, and then converge through the convex surface of the image-side surface S11, forming a "divergent-convergent" optical path buffer, avoiding energy concentration and loss due to the light beam converging too quickly.

[0057] In other words, the first lens E11 has positive optical power, which on the one hand helps to reduce the divergence angle of the incident beam in the X and Y directions, and on the other hand, it converges the incident beam towards the central optical axis oo'.

[0058] The second lens E12 has a positive optical power, and both the object side S12 and the image side S13 of the second lens E12 are convex surfaces; the third lens E13 has a positive optical power, and both the object side S14 and the image side S15 of the third lens E13 are convex surfaces.

[0059] The second lens E12 and the third lens E13 are positive optical powers. The second lens E12 inherits the initial converging effect of the first lens E11, and the third lens E13 inherits the converging effect of the second lens E12, further compressing the beam divergence angle. Since the object side and image side of the second lens E12 and the third lens E13 are both convex surfaces, the divergence angle of the incident beam passing through the first lens E11 in the X and Y directions is further reduced, and the converging efficiency is further improved.

[0060] It is understandable that, for scenarios where the light-emitting surface L10 of the light-emitting chip has a large NA divergence angle, the first lens E11, the second lens E12, and the third lens E13 can reduce the divergence angle of the incident beam in the X and Y directions, and gradually bend the beam smoothly towards the central optical axis oo' in the X direction, thereby achieving the first-stage expansion of the large field of view and wide-angle output beam.

[0061] Among them, the optical power of the fourth lens E14 is negative, the object side S16 of the fourth lens E14 is concave, and the image side S17 is convex.

[0062] The fourth lens E14 has negative optical power, which can not only balance the divergence angle of the emitted beam in the X and Y directions and reduce the difference in the divergence angle of the emitted beam in the X and Y directions, but also deviate the emission direction of the emitted beam from the central optical axis oo' based on the first-level expansion angle in the X direction, so as to realize the second-level expansion of the emitted beam with a large field of view and a wide angle.

[0063] Among them, the optical power of the fifth lens E15 is negative, the object side S18 of the fifth lens E15 is concave, the image side S19 is convex, and the fifth lens E15 is an aspherical lens.

[0064] The fifth lens E15 has negative optical power, which can not only further extend the angle of the beam passing through the fourth lens E14 in the X direction to a large field of view and a wide angle of exit, but also balance the difference in beam divergence angle in the X and Y directions.

[0065] It is understandable that the fourth lens E14 is located between the third lens E13 and the fifth lens E15. It can smoothly bend the light of the output beam with a large field of view and wide angle, avoid large angle changes, reduce the sensitivity of the system, and reduce the rear port diameter of the optical module 10, thereby reducing the volume. This is beneficial for the miniaturization of the lens of the optical module 10 and reducing the production cost.

[0066] The optical module 10 satisfies the following relationship: 0.15 ≤ d1 / TTL ≤ 0.22, where d1 is the distance on the optical axis from the image-side surface S17 of the fourth lens E14 to the object-side surface S18 of the fifth lens E15, and TTL is the total optical length of the optical module 10. For example, d1 / TTL can be any value within the range of [0.15, 0.22], such as 0.15, 0.18, 0.2, 0.221, etc.

[0067] Since both the fourth lens E14 and the fifth lens E15 have negative optical power, when d1 / TTL ≤ 0.15, the distance between the two lenses is insufficient. The incident beam exiting from the fourth lens E14 rapidly enters the fifth lens E15, causing a sudden change in the divergence angle and angle jumps at the edge of the field of view, resulting in a reduced FOV and difficulty in achieving large angles. When d1 / TTL ≥ 0.22, the beam diverges excessively in the air layer between the two lenses. The fifth lens E15 cannot effectively control the edge beam, potentially leading to higher energy loss and worsening F-Theta distortion.

[0068] Therefore, by constraining 0.15≤d1 / TTL≤0.22, it is beneficial to rationally allocate the air gap between the fourth lens E14 and the fifth lens E15, reduce the total optical length, and also ensure the size design of external structural components, avoiding structural components that are too small or too long.

[0069] Thus, by setting the first lens E11, the second lens E12, and the third lens E13 as positive power lenses, it is beneficial for light to converge. Even if the emitting position of the emitting surface L10 is far from the optical axis, the emitted beam from the edge emitting unit can be smoothly bent towards the central optical axis, allowing the converged light to smoothly enter the fourth lens E14. The fourth lens E14 and the fifth lens E15 are negative power lenses, which is beneficial for light to diverge. They deflect the incident beam that has passed through the first lens E11, the second lens E12, and the third lens E13 away from the central optical axis, expanding the field of view of the emitted beam. This allows the emitted beam to exit with a large field of view and a wide-angle exit, and also allows for uniform light emission in the X and Y directions. In addition to beam divergence, the fourth lens E14 also has a light transition function. After receiving the incident beam bent by the third lens E13, the fourth lens E14 can make the incident beam smoothly enter the fifth lens E15. The smooth propagation of the beam between the first lens E11, the second lens E12, the third lens E13, the fourth lens E14 and the fifth lens E15 helps to reduce the manufacturing cost of the lens. By constraining 0.15≤d1 / TTL≤0.22, it is beneficial to reasonably allocate the air gap between the fourth lens E14 and the fifth lens E15, reduce the total optical length, and also ensure the size design of the external structural components, avoiding the structural components being too small or too long.

[0070] In other words, by setting five lenses and optimizing the optical power of each lens and constraining the lens spacing, this application achieves high collimation of the collimated beam emitted from the optical module 10 provided in this embodiment, and the emitted collimated beam has the characteristics of a large field of view and a wide angle. It also achieves a short lens length and a small lens aperture.

[0071] Optionally, the first lens E11, the second lens E12, the third lens E13 and the fourth lens E14 are spherical lenses, and the fifth lens E15 is an aspherical lens.

[0072] The curvature center of the spherical lens is coaxial with the optical axis, ensuring uniform refraction of light. The first lens E11, the second lens E12, and the third lens E13 are spherical lenses, facilitating progressive collimation among these positive-power lenses. The fourth lens E14, with negative power, is also a spherical lens. Its asymmetrical curvature in the X and Y directions compensates for the difference in NA (nano) of the emitting surface L10, balancing the divergence angle and laying a uniform foundation for the wide field of view expansion of the fifth lens E15. The fifth lens E15 is an aspherical lens. Aspherical lenses can specifically correct aberrations in edge beams, controlling distortion. The asymmetrical curvature of the aspherical lens, combined with its negative power, prevents edge ray truncation when the beam diverges, achieving a synergistic expansion of the field of view.

[0073] In some embodiments, the optical module 10 satisfies the following relationship: 0.26 ≤ EFL1 / d2 ≤ 0.31;

[0074] Where EFL1 is the combined focal length of the first lens E11, the second lens E12, and the third lens E13, and d2 is the distance on the optical axis from the emitting surface L10 to the image side surface S15 of the third lens E13. For example, EFL1 / d2 can be any value within the range of [0.26, 0.31], such as 0.26, 0.27, 0.30, 0.31, etc.

[0075] When the above relationship is satisfied, it is beneficial to rationally allocate the focal length of the front group (i.e., the combination of the first lens E11, the second lens E12 and the third lens E13), reduce the total optical length, and realize lens miniaturization. On the other hand, it enables light to propagate smoothly between the first lens E11, the second lens E12 and the third lens E13.

[0076] In some implementations, the optical module 10 satisfies the following relationship: TTL / H / FOV ≤ 0.04;

[0077] Where H is the height of the light-emitting surface L10 along the diagonal in the vertical direction, and FOV is the field of view of the optical module 10. For example, TTL / H / FOV can be values ​​in the range of [0, 0.04] such as 0.01, 0.02, 0.03, etc.

[0078] When the above relationship is satisfied, it is beneficial to minimize the size of the optical lens under the same light-emitting surface L10 height and exit field of view angle.

[0079] In some implementations, the optical module 10 satisfies the following relationship: FFL / TTL ≥ 0.08;

[0080] Wherein, FFL is the distance on the optical axis from the light-emitting surface L10 to the object-side surface S10 of the first lens E11. For example, FFL / TTL can be 0.08, 0.09, 0.01, 0.02, etc.

[0081] Furthermore, FFL / TTL ≥ 0.1. For example, FFL / TTL can be 0.01, 0.02, 0.03, etc.

[0082] When the above relationship is satisfied, it is beneficial to make the optical module 10 have a longer front focal surface on the basis of miniaturization, and it is also easier to assemble the structure of the optical module 10.

[0083] In some embodiments, the optical module 10 satisfies the following relationship: 0.2≤(H / 2) / (EFL2*tan(FOV / 2))≤0.3; for example, (H / 2) / (EFL2*tan(FOV / 2)) can be a value in the range of [0.2, 0.3], such as 0.2, 0.22, 0.25, 0.28, 0.3, etc.

[0084] Where H is the height of the light-emitting chip along the diagonal in the vertical direction, EFL2 is the combined focal length of the first lens E11, the second lens E12, the third lens E13, the fourth lens E14 and the fifth lens E15, that is, the total effective focal length of the optics, and FOV is the maximum field of view of the optical module 10, in radians.

[0085] Satisfying the above relationship is beneficial for achieving large angular resolution (large angular resolution refers to the angular resolution capability of the LiDAR 100 optical system for distinguishing adjacent targets in space, that is, the minimum angular difference that the system can distinguish between two adjacent targets).

[0086] In some implementations, the optical module 10 satisfies the following relationship: TTL / EFL2 ≤ 10.4; for example, TTL / EFL2 can be 10.3, 10.0, 9.5, etc.

[0087] EFL2 is the combined focal length of the first lens E11, the second lens E12, the third lens E13, the fourth lens E14, and the fifth lens E15.

[0088] Satisfying the above relationship is beneficial for reducing the overall optical length and further achieving miniaturization.

[0089] In some embodiments, the optical module 10 satisfies the following relationship: EFL2 / Φ≥0.17; for example, EFL2 / Φ can be 0.16, 0.15, 0.1, etc.

[0090] Wherein, EFL2 is the combined focal length of the first lens E11, the second lens E12, the third lens E13, the fourth lens E14 and the fifth lens E15, and Φ is the aperture corresponding to the preset field of view angle of the fifth lens E15.

[0091] The preset field of view angle is ±80° of the maximum angle of the fifth lens E15.

[0092] When the above relationship is satisfied, the optical module 10 can accommodate edge beams of ±80° field of view, avoiding field shrinkage or energy loss due to insufficient aperture, and further ensuring a large field of view; it also helps to reduce the outer diameter of the largest lens in the system and realize the miniaturization of the lens structure.

[0093] In some embodiments, the optical module 10 satisfies the following relationship: 0.8 ≤ f1 / f2 ≤ 1.5; and / or 1.2 ≤ f2 / f3 ≤ 1.8; for example, f1 / f2 can be a value in the range of [0.8, 1.5] such as 0.9, 1, 1.2; f2 / f3 can be a value in the range of [1.2, 1.8] such as 1.2, 1.3, 1.5.

[0094] Where f1 is the focal length of the first lens E11, f2 is the focal length of the second lens E12, and f3 is the focal length of the third lens E13.

[0095] When the above relationship is satisfied, by controlling the focal length relationship between the first lens E11, the second lens E12 and the third lens E13, it is beneficial for the incident beam to transition smoothly between the first lens E11, the second lens E12 and the third lens E13, thereby reducing the lens processing and manufacturing cost.

[0096] In some implementations, the optical module 10 satisfies the following relationship: 0.7 ≤ |EFL1 / EFL3| ≤ 1.3; for example, |EFL1 / EFL3| can be a value in the range of [0.8, 1.3] such as 0.8, 1, 1.3, etc.

[0097] Wherein, EFL1 is the combined focal length of the first lens E11, the second lens E12, the third lens E13, the fourth lens E14, and the fifth lens E15, and EFL3 is the combined focal length of the fourth lens E14 and the fifth lens E15.

[0098] When the above relationship is satisfied, by controlling the reasonable ratio of EFL1 and EFL3, it is beneficial for light to propagate smoothly from the third lens E13 to the fourth lens E14 and the fifth lens E15. EFL1 is a lens group with positive optical power, and EFL3 is a lens group with negative optical power. Controlling the reasonable ratio of EFL1 and EFL3 is beneficial for the optical lens to still have excellent resolution in environments with large temperature differences.

[0099] In some implementations, the optical module 10 satisfies the following relationship: 18°≤|θ1-θ2|≤26°; for example, |θ1-θ2| can be any value in the range of [18°, 26°] such as 18°, 20°, 22°, 25°, etc.

[0100] Where θ1 is the maximum incident angle of the light ray on the object side S18 of the fifth lens E15, and θ2 is the maximum exit angle of the light ray on the image side S19 of the fifth lens E15.

[0101] When the above relationship is satisfied, by reasonably controlling the difference between the incident angle and the exit angle of the incident light on the front and back of the fifth lens E15 along the optical axis, it is beneficial to achieve a wide-angle FOV exit. On the other hand, it also enables the light to propagate smoothly in the fourth lens E14 and the fifth lens E15.

[0102] In some embodiments, the optical module 10 further includes:

[0103] An aperture stop is positioned between the third lens E13 and the fourth lens E14.

[0104] The aperture stop is used to limit the beam aperture, eliminate energy side lobes around the emitted light, and improve the collimation of the emitted beam. When the incident beam exits from the third lens E13, it completes the final stage of beam convergence, at which point the beam diameter is at its smallest. By placing the aperture stop between the third lens E13 and the fourth lens E14, it is possible to efficiently filter stray light. In other words, by placing the aperture stop at the transition node between beam convergence and divergence, it is possible to ensure that the filtered beam enters the fourth lens E14, preventing stray light from being further amplified during the divergence process.

[0105] It should be noted that the optical module 10 proposed in this application can achieve the results and advantages described in this specification by changing the number of lenses in the lens. For example, in this application, a lens can be inserted between the first lens E11 and the second lens E12, which together with the first lens E11, the second lens E12, and the third lens E13 constitute the front lens group, achieving the same function as the front lens group. Alternatively, the second lens E12 can be removed, and the first lens E11 and the third lens E13 can together constitute the front lens group, achieving the same function as the front lens group. These changes, as long as they do not depart from the specific constraints of this patent, will be considered as the content protected by this patent.

[0106] The embodiments provided in this application will now be described in detail.

[0107] First Embodiment

[0108] Please see Figure 2 In the optical module 10 of the first embodiment, from the light-emitting surface L10 of the light-emitting chip to the image side, there are a first lens E11, a second lens E12, a third lens E13, a fourth lens E14 and a fifth lens E15. The first lens E11, the second lens E12, the third lens E13, the fourth lens E14 and the fifth lens E15 are arranged sequentially along the light emission direction.

[0109] The first lens E11 has a positive optical power, its object-side surface S10 is concave, and its image-side surface S11 is convex. The first lens E11 is configured to receive the incident light beam. The second lens E12 has a positive optical power, and both its object-side surface S12 and image-side surface S13 are convex. The third lens E13 has a positive optical power, and both its object-side surface S14 and image-side surface S15 are convex. The fourth lens E14 has a negative optical power, its object-side surface S16 is concave, and its image-side surface S17 is convex. The fifth lens E15 has a negative optical power, its object-side surface S18 is concave, and its image-side surface S19 is convex.

[0110] Among them, the first lens E11, the second lens E12, the third lens E13 and the fourth lens E14 are all spherical lenses, and the fifth lens E15 is an aspherical lens.

[0111] The aperture stop is positioned between the third lens E13 and the fourth lens E14.

[0112] Please refer to Table 1, which shows the radius of curvature R, lens thickness, and lens spacing d along the optical axis oo' for each surface of each lens in the first embodiment, as well as the range of refractive index of the optical glass. The light-emitting surface L10 of the light-emitting chip has a diagonal height H of 5.72 mm, a numerical aperture NA of 0.26, and a diagonal DFOV of 160° for the light beam exiting from the image side of the fifth lens E15.

[0113] Surface type Face number radius of curvature R Thickness d Glass refractive index Nd spherical L10 infinity 2.261 spherical S10 -24.853 3.96 1.65-1.80 spherical S11 -7.793 0.173 spherical S12 11.7145 4 1.65-1.80 spherical S13 -24.714 0.172 spherical S14 7.109 3.48 1.65-1.80 spherical S15 (STO) -27.244 0.505 spherical S16 -5.1 2 1.48-1.68 spherical S17 -6.224 4.2 aspherical S18 -6.463 0.8 1.60-1.77 aspherical S19 -8.31

[0114] Table 1

[0115] Among them, the object-side surface S18 of the fifth lens E15 and the image-side surface S19 of the collimating beam are aspherical surfaces. The surface shape of each aspherical surface can be expressed using, but is not limited to, the following aspherical surface expression formula:

[0116]

[0117] Where ZASPH(Y) is the distance vector from the vertex of the aspherical surface at a position of height Y along the optical axis oo', R is the radius of curvature of the aspherical surface corresponding to Table 1, k is the conic coefficient, and A, B, C, D, E, F, and G correspond to the coefficients of the binomial, tetranomial, hexanomial, octomial, decimal, dodecomial, and quintomial expressions, respectively.

[0118] Please refer to Table 2, which shows the corresponding conic coefficients and polynomial coefficients for the object side S18 and image side S19 of the fifth lens E15.

[0119] noodle k A B C D E F G S18 3.911 -1.289E-01 -4.08E-03 -2.814E-04 5.213E-05 -3.087E-05 4.757E-06 -3.489E-07 S19 0.2112 1.382E-02 2.545E-04 -1.306E-05 6.279E-07 -4.516E-09 -3.791E-11 3.535E-13

[0120] Table 2

[0121] Please refer to Table 3. Table 3 shows the collimated beam field of view (FOV / 2) and the magnitude of 0.5 times the divergence in the collimation direction of the collimated beam after the emitted light from the light-emitting chip L10 passes through the first lens E11, the second lens E12, the third lens E13, the fourth lens E14 and the fifth lens E15 at different heights in the first embodiment.

[0122] Object height (mm) Exit field of view (degrees) RMS angular radius (degrees) 0 0 8.60E-02 0.5 13.93 8.23E-02 1 27.81 7.85E-02 1.5 41.52 8.85E-02 2 55 9.39E-02 2.5 68.71 8.27E-02 2.86 79.9 1.00E-01

[0123] Table 3

[0124] Please see Figure 3 , Figure 3 The diagram illustrates the shape of the F-theta distortion curve of the first embodiment. For the object-side telecentric and image-side afocal optical system in this embodiment, the F-theta distortion curve can intuitively illustrate the degree of deviation between the actual and ideal values ​​of the exit angle of the collimated beam.

[0125] Second Embodiment

[0126] Please refer to Figure 4 Table 4 shows the radius of curvature R, lens thickness, and lens spacing d along the optical axis oo' for each surface of the lenses in the second embodiment, as well as the range of refractive index of the optical glass. The light-emitting surface L10 of the light-emitting chip has a diagonal height H of 5.72 mm, a numerical aperture NA of 0.26, and a diagonal DFOV of 160° for the light beam exiting from the image side of the fifth lens E15.

[0127]

[0128]

[0129] Table 4

[0130] Please refer to Table 5, which shows the corresponding conic coefficients and polynomial coefficients for the object side S18 and image side S19 of the fifth lens E15.

[0131] noodle k A B C D E F G S18 2.793 -1.139E-01 -2.993E-03 -4.553E-04 1.007E-04 -3.335E-05 4.337E-06 -2.898E-07 S19 0.312 6.943E-03 2.195E-04 -1.751E-05 6.715E-07 -4.567E-09 -5.292E-11 3.157E-13

[0132] Table 5

[0133] Please refer to Table 6. Table 6 shows the collimated beam field of view (FOV / 2) and the magnitude of 0.5 times the divergence in the collimation direction of the collimated beam after the emitted light from the light-emitting unit passes through the first lens E11, the second lens E12, the third lens E13, the fourth lens E14 and the fifth lens E15 at different heights in the second embodiment.

[0134] Object height (mm) Exit field of view (degrees) RMS angular radius (degrees) 0 0 9.77E-02 0.5 13.83 9.33E-02 1 27.64 8.29E-02 1.5 41.39 8.53E-02 2 55 9.62E-02 2.5 68.73 8.31E-02 2.8569 79.64 8.74E-02

[0135] Table 6

[0136] Please see Figure 5 , Figure 5 The diagram illustrates the shape of the F-theta distortion curve in the second embodiment. For the object-centric and image-afocal optical system in this embodiment, the F-theta distortion curve can visually illustrate the degree of deviation between the actual and ideal values ​​of the collimated beam's exit angle.

[0137] Third Embodiment

[0138] Please see Figure 6 Table 7 shows the radius of curvature R, lens thickness, and lens spacing d along the optical axis oo' for each surface of the lenses in the third embodiment, as well as the range of refractive indices of the optical glass. The light-emitting surface L10 of the light-emitting chip has a diagonal height H of 5.72 mm, a numerical aperture NA of 0.26, and a diagonal DFOV of 160° for the beam exiting from the image side of the fifth lens E15.

[0139] Surface type Face number radius of curvature R Thickness d Glass refractive index Nd spherical L10 infinity 2.223 spherical S10 -13.925 3.1 1.69-1.82 spherical S11 -7.074 0.449 spherical S12 13.341 3.5 1.69-1.82 spherical S13 -19.436 0.165 spherical S14 7.146 3.97 1.69-1.82 spherical S15 (STO) -21.753 0.512 spherical S16 -4.732 2 1.51-1.72 spherical S17 -5.667 3.97 aspherical S18 -6.233 0.8 1.59-1.79 aspherical S19 -10.947

[0140] Table 7

[0141] Please refer to Table 8, which shows the corresponding conic coefficients and polynomial coefficients for the object side S18 and image side S19 of the fifth lens E15.

[0142] noodle k A B C D E F G S18 3.661 -1.209E-01 -4.022E-03 -3.236E-04 7.095E-05 -3.250E-06 4.087E-06 -2.676E-07 S19 0.929 4.399E-03 -5.673E-03 -1.170E-05 7.868E-07 -9.390E-09 -1.955E-11 4.832E-13

[0143] Table 8

[0144] Please refer to Table 9. Table 9 shows the collimated beam field of view (FOV / 2) and the magnitude of 0.5 times the divergence in the collimation direction of the collimated beam after the emitted light from the light-emitting unit passes through the first lens E11, the second lens E12, the third lens E13, the fourth lens E14, and the fifth lens E15 at different heights of the half-height of the diagonal of the light-emitting surface L10 of the light-emitting chip in the third embodiment.

[0145] Object height (mm) Exit field of view (degrees) RMS angular radius (degrees) 0 0.0 9.41E-02 0.5 13.91 8.99E-02 1 27.83 8.45E-02 1.5 41.6 8.54E-02 2 55.12 8.52E-02 2.5 68.7 8.29E-02 2.8569 79.53 1.05E-01

[0146] Table 9

[0147] Please see Figure 7 , Figure 7 The diagram illustrates the shape of the F-theta distortion curve in the third embodiment. For the object-centric and image-afocal optical system in this embodiment, the F-theta distortion curve can visually illustrate the degree of deviation between the actual and ideal values ​​of the collimated beam's exit angle.

[0148] Fourth embodiment

[0149] Please see Figure 8 Table 10 shows the radius of curvature R, lens thickness, and transmission characteristics of each surface of the lens in the fourth embodiment.

[0150] The distance d between the mirrors along the optical axis oo' and the range of the refractive index of the optical glass. The light-emitting surface L10 of the light-emitting chip has a diagonal height H of 5.72 mm, a numerical aperture NA of 0.26, and a diagonal DFOV of 160° for the light beam exiting from the image side of the fifth lens E15.

[0151] Surface type Face number radius of curvature R Thickness d Glass refractive index Nd spherical L10 infinity 2.19 spherical S10 -18.000 3.0 1.76-1.86 spherical S11 -7.23 0.489 spherical S12 15.77 3.2 1.52-1.82 spherical S13 -15.77 0.57 spherical S14 6.776 3.2 1.69-1.78 spherical S15 (STO) -22.244 0.512 spherical S16 -5.19 2 1.55-1.72 spherical S17 -6.052 4.24 aspherical S18 -6.28 0.8 1.59-1.79 aspherical S19 -8.32

[0152] Table 10

[0153] Please refer to Table 11, which shows the corresponding conic coefficients and polynomial coefficients for the object side S18 and image side S19 of the fifth lens E15.

[0154] noodle k A B C D E F G S18 3.98 -1.321E-01 -4.348E-03 -3.427E-04 4.985E-05 -3.129E-05 4.895E-06 -4.071E-07 S19 0.312 1.474E-02 2.294E-04 -1.279E-05 6.32E-07 -3.413E-09 -3.651E-11 1.441E-14

[0155] Table 11

[0156] Please refer to Table 12. Table 12 shows the collimated beam field of view (FOV / 2) and the magnitude of 0.5 times the divergence in the collimation direction of the collimated beam after the emitted light from the light-emitting unit passes through the first lens E11, the second lens E12, the third lens E13, the fourth lens E14, and the fifth lens E15 at different heights of the half-height of the diagonal of the light-emitting surface L10 of the light-emitting chip in the fourth embodiment.

[0157] Object height (mm) Exit field of view (degrees) RMS angular radius (degrees) 0 0.0 9.82E-02 0.5 13.93 9.43E-02 1 27.83 8.69E-02 1.5 41.59 9.85E-02 2 55.1 1.08E-01 2.5 68.68 1.03E-01 2.8569 79.55 1.09E-01

[0158] Table 12

[0159] Please see Figure 9 , Figure 9 The diagram illustrates the shape of the F-theta distortion curve in the fourth embodiment. For the object-centric and image-afocal optical system in this embodiment, the F-theta distortion curve can visually illustrate the degree of deviation between the actual and ideal values ​​of the collimated beam's exit angle.

[0160] In summary, please refer to Table 13, which exemplarily illustrates the constraint variables and the relationships between the variables satisfied in the first embodiment to the fourth embodiment, respectively.

[0161]

[0162] Table 13

[0163] Please see Figure 1 The light emitter 100 of the present invention includes an optical module 10 and a light-emitting chip in any of the above embodiments, and the light-emitting chip is disposed on the object side of the first lens E11.

[0164] The lidar 100 of this invention includes a light emitter and a light receiver according to any of the above embodiments.

[0165] The vehicle 1000 of the present invention includes the lidar 100 of any of the above embodiments.

[0166] In the description of this specification, the references to terms such as "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with the described embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0167] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the stated features. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0168] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention, which is defined by the claims and their equivalents.

Claims

1. An optical module, characterized in that, include: A first lens, wherein the optical power of the first lens is positive, the object side of the first lens is concave and the image side is convex, and the first lens is configured to receive an incident light beam. The second lens has a positive optical power, and both its object-side and image-side surfaces are convex. The third lens has a positive optical power, and both its object-side and image-side surfaces are convex. The fourth lens has a negative optical power, and its object side is concave while its image side is convex. The fifth lens has a negative optical power, and its object side is concave while its image side is convex. The first lens, the second lens, the third lens, the fourth lens, and the fifth lens are arranged sequentially along the light emission direction, and the optical module satisfies the following relationship: 0.15≤d1 / TTL≤0.22; Wherein, d1 is the distance on the optical axis from the image side of the fourth lens to the object side of the fifth lens, and TTL is the total optical length of the optical module.

2. The optical module according to claim 1, characterized in that, The optical module satisfies the following relationship: 0.26≤EFL1 / d2≤0.31; Wherein, EFL1 is the combined focal length of the first lens, the second lens and the third lens, and d2 is the distance on the optical axis from the emitting surface to the image side of the third lens.

3. The optical module according to claim 1, characterized in that, The optical module satisfies the following relationship: TTL / H / FOV≤0.04; Where H is the height of the emitting surface along the diagonal in the vertical direction, and FOV is the field of view of the optical module.

4. The optical module according to claim 1, characterized in that, The optical module satisfies the following relationship: FFL / TTL ≥ 0.08; Wherein, FFL is the distance on the optical axis from the light-emitting surface to the object-side surface of the first lens.

5. The optical module according to claim 4, characterized in that, The optical module satisfies the following relationship: FFL / TTL≥0.

1.

6. The optical module according to claim 1, characterized in that, The optical module satisfies the following relationship: 0.2≤(H / 2) / (EFL2*tan(FOV / 2))≤0.3; Where H is the height of the light-emitting chip along the diagonal in the vertical direction, EFL2 is the combined focal length of the first lens, the second lens, the third lens, the fourth lens and the fifth lens, and FOV is the maximum field of view of the optical module.

7. The optical module according to claim 1, characterized in that, The optical module satisfies the following relationship: TTL / EFL2≤10.4; Wherein, EFL2 is the combined focal length of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens.

8. The optical module according to claim 1, characterized in that, The optical module satisfies the following relationship: EFL2 / Φ≥0.17; Wherein, EFL2 is the combined focal length of the first lens, the second lens, the third lens, the fourth lens and the fifth lens, and Φ is the aperture corresponding to the preset field of view angle of the fifth lens.

9. The optical module according to claim 1, characterized in that, The optical module satisfies the following relationship: 0.8 ≤ f1 / f2 ≤ 1.5; and / or 1.2≤f2 / f3≤1.8; Where f1 is the focal length of the first lens, f2 is the focal length of the second lens, and f3 is the focal length of the third lens.

10. The optical module according to claim 1, characterized in that, The optical module satisfies the following relationship: 0.7 ≤ |EFL1 / EFL3| ≤ 1.3; Wherein, EFL1 is the combined focal length of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens, and EFL3 is the combined focal length of the fourth lens and the fifth lens.

11. The optical module according to claim 1, characterized in that, The optical module satisfies the following relationship: 18°≤|θ1-θ2|≤26°; Wherein, θ1 is the maximum incident angle of the light on the object side of the fifth lens, and θ2 is the maximum exit angle of the light on the image side of the fifth lens.

12. The optical module according to claim 1, characterized in that, The first lens, the second lens, the third lens, and the fourth lens are all spherical lenses, and the fifth lens is an aspherical lens.

13. The optical module according to claim 1, characterized in that, The optical module also includes: An aperture stop is disposed between the third lens and the fourth lens.

14. A light emitter, characterized in that, include: The optical module according to any one of claims 1-12; and A light-emitting chip is disposed on the object side of the first lens.

15. The light emitter according to claim 14, characterized in that, The light-emitting chip includes at least one of an area array light-emitting chip, a linear array light-emitting chip, and a pulsed laser.

16. A lidar, characterized in that, include: The light emitter as described in claim 14 or 15; and Optical receiver.

17. A vehicle, characterized in that, include: The lidar as described in claim 16.

Images