Optical lens and optical receiving system

Abstract

An optical lens (200) and an optical receiving system (10) are disclosed. The optical lens (200) includes a lens assembly (210, 220), an aperture stop (260, 300), and a beam splitter (270). The lens assembly (210, 220) is used to receive and transmit a first light beam with a wavelength in a first band and a second light beam with a wavelength in a second band. The aperture stop (260, 300) includes an aperture portion (310) having a first radial dimension and a through-hole (320) having a second radial dimension; the through-hole (320) is used to allow light beams with wavelengths in the first and second bands to pass through; the aperture portion (310) is used to restrict the transmission of light beams with wavelengths in the first band and transmit light beams with wavelengths in the second band. The beam splitter (270) is used to separate the first light beam and the second light beam. The optical lens (200) and the optical receiving system (10) can be applied to intelligent vehicles or new energy vehicles. They can meet the different optical hardware requirements of different detection systems through the same lens, which is conducive to the integration of the optical hardware level of cameras and lidar.

Description

Optical lenses and optical receiving systems Technical Field

[0001] This application relates to the field of detection technology, and more specifically, to an optical lens and an optical receiving system. Background Technology

[0002] LiDAR and cameras, as detection devices, are widely used in various scenarios, such as smart cars and drones. However, using a single detection device inevitably has limitations. For example, external lighting conditions can severely affect the quality of images captured by cameras; and because the point clouds collected by LiDAR may be disordered and sparse, it may be difficult to intuitively distinguish the types of objects based solely on the point cloud. By fusing images with point clouds, the detection system's object perception accuracy can be improved, and its adaptability to the environment can be enhanced.

[0003] However, due to the conflicting optical performance requirements of LiDAR and cameras, it is difficult to achieve the fusion of LiDAR and cameras at the optical hardware level, which limits the fusion effect of point clouds and images.

[0004] Summary of the Invention

[0005] This application provides an optical lens and an optical receiving system that can use the same lens to meet the different F-number requirements of different detection devices, and can realize the fusion of lidar and camera at the optical hardware level.

[0006] In a first aspect, an optical lens is provided. The optical lens includes a lens assembly, an aperture stop, and a beam splitter. The lens assembly is used to receive and transmit a first light beam with a wavelength in a first band and a second light beam with a wavelength in a second band. The aperture stop includes an aperture portion having a first radial dimension and a through-hole having a second radial dimension; the through-hole is used to allow the light beams with wavelengths in the first and second bands to pass through; the aperture portion is used to restrict the transmission of the light beam with a wavelength in the first band and to transmit the light beam with a wavelength in the second band. The beam splitter is used to separate the first light beam and the second light beam.

[0007] For example, the optical lens may include one or more lens assemblies. For instance, a light beam entering the lens may first pass through a lens assembly and then through the aperture stop. Alternatively, the light beam entering the lens may first pass through the aperture stop and then through the lens assembly. Or, for example, it may first pass through one lens assembly, then through the aperture stop, and then through other lens assemblies.

[0008] In one example, the aperture stop can be disc-shaped, and the through-hole of the aperture stop can be a circular through-hole located at the center of the disc. In this example, the diameter of the disc can correspond to a first radial dimension; the diameter of the through-hole can correspond to a second radial dimension.

[0009] In this application, for the first and second waveband beams, on the one hand, the beams of both wavebands propagate through the same lens assembly within the lens, allowing the optical lens to have the same focal length in both wavebands; on the other hand, because the aperture stop restricts the propagation of the first waveband beam, the first and second waveband beams can correspond to different entrance pupil diameters. In this way, the same lens can meet the different entrance pupil diameter requirements of different detection devices, and also meet the different F-number requirements of different detection devices.

[0010] In some possible implementations, the entrance pupil diameter of the optical lens in the first band can be determined based on the second radial dimension; the entrance pupil diameter of the optical lens in the second band can be determined based on the first radial dimension.

[0011] For example, if an optical lens includes only one aperture stop, the entrance pupil diameter in the first band can be the second radial dimension, and the entrance pupil diameter in the second band can be the first radial dimension. Alternatively, if the optical lens also includes other aperture stops, the entrance pupil diameter in the first band can be determined based on the second radial dimension and the characteristic parameters of the other aperture stops.

[0012] In this application, by setting the aperture stop, the optical lens can have different entrance pupil diameters in these two wavebands, thereby simultaneously meeting the different entrance pupil diameter requirements of different detection devices.

[0013] In some possible implementations, the optical lens may have a first F-number in the first band, which may be determined based on the second radial dimension and the focal length of the lens assembly; the optical lens may have a second F-number in the second band, which may be determined based on the first radial dimension and the focal length of the lens assembly.

[0014] Since the F-number is the ratio of the lens's focal length to its entrance pupil diameter, and this optical lens can have the same focal length in both the first and second wavelength bands, this application allows the optical lens to have different F-numbers in these two wavelength bands by setting the aperture stop, thus simultaneously meeting the different F-number requirements of different detection systems.

[0015] In some possible implementations, the first F-number can be greater than or equal to 1.2 and less than 3.0; the second F-number can be greater than or equal to 1.0 and less than 2.0; and the first F-number can be greater than the second F-number.

[0016] In one example, the first F-number of the lens could be 1.6, and the second F-number could be 1.2.

[0017] In real-world scenarios, for vehicle cameras, in order to balance the amount of light intake with the background blur effect of the image, as well as the requirements of high and low temperature adaptability and reliability, the F-number of the lens is usually expected to be in the range of 1.2 to 3.0; for LiDAR, in order to ensure sufficient light intake so that it can have a good detection effect on distant targets, the F-number of the lens is usually expected to be in the range of 1.0 to 2.0.

[0018] In this application, by setting the aperture stop, the first F-number of the optical lens can be within the range of 1.2 to 3.0 to meet the requirements of automotive cameras; and the second F-number of the optical lens can be within the range of 1.0 to 2.0 to meet the requirements of LiDAR. By taking into account the F-number requirements of both automotive cameras and LiDAR, the fusion of automotive cameras and LiDAR at the optical hardware level can be achieved.

[0019] In some possible implementations, the aperture portion may include a transparent substrate that can be used to transmit light beams with wavelengths in the second band.

[0020] For example, even if the transparent substrate itself does not have a filtering function, it can still allow light beams of both the first and second wavelengths to pass through. In this case, an optical film (such as a filter film or an anti-reflection film) can be applied to the surface of the transparent substrate to meet the light transmission requirements of the aperture section.

[0021] For example, when a transparent substrate has a filtering function, on the one hand, light beams of the second wavelength band can be transmitted through the transparent substrate, and on the other hand, the transparent substrate can restrict the transmission of light beams of certain wavelength bands (such as light beams with wavelengths in the first wavelength band).

[0022] In some possible implementations, the transparent substrate can also be used to restrict the transmission of light beams with wavelengths in the first band.

[0023] In this application, the transparent substrate itself can have a light filtering function to limit the transmission of the first wavelength beam; in this case, even without additional light filtering film, the light transmission requirements of the aperture part can be met, which can simplify the structure and manufacturing process of the aperture part.

[0024] In some possible implementations, the aperture stop may further include a first filter film disposed on the surface of the transparent substrate. The first filter film can be used to restrict the transmission of light beams with wavelengths in a first band and to transmit light beams with wavelengths in a second band.

[0025] In this application, by setting a first filter film on the surface of a transparent substrate, the transmission of a first-wavelength light beam can be restricted while allowing the transmission of a second-wavelength light beam. In this case, even if the transparent substrate itself does not have a filtering function, the light transmission requirements of the aperture section can still be met. Moreover, by adjusting the performance of the filter film, the light transmission performance of the aperture section can be flexibly adjusted, which is beneficial for matching the usage requirements in different scenarios.

[0026] In some possible implementations, the transparent substrate can be made of glass or plastic.

[0027] In some possible implementations, the beam-splitting element may include a beam-splitting prism, which may include a first emitting surface and a second emitting surface. The beam-splitting prism can be used to emit a light beam with a wavelength in a first band from the first emitting surface and a light beam with a wavelength in a second emitting surface.

[0028] In this application, a beam-splitting prism is used for beam splitting. On the one hand, the back focal length of the lens can be designed to be relatively short, saving space and contributing to the miniaturization of the detection system. On the other hand, the beam-splitting surface of the beam-splitting prism has lower requirements for the incident angle of the beam, which can reduce the difficulty of optical path design. In addition, the two beams obtained by beam splitting using a beam-splitting prism have the same optical path, which can improve the registration effect.

[0029] In some possible implementations, the first light-emitting surface may be provided with a second filter film, which can be used to transmit light beams with wavelengths in the first band and restrict the transmission of light beams with wavelengths in the second band; the second light-emitting surface may be provided with a third filter film, which can be used to transmit light beams with wavelengths in the second band and restrict the transmission of light beams with wavelengths in the first band.

[0030] In practical implementations, some beam splitters may have poor beam splitting performance; for example, under the beam splitting action of a beam splitter, a portion of the beam with wavelengths in the second band may be guided to the first light-emitting surface. In this application, by setting a second filter and a third filter, it is beneficial to ensure the final beam splitting effect of the beam splitting element.

[0031] In some possible implementations, the beam-splitting element may include a dichroic mirror. This dichroic mirror can be used to transmit a first beam and reflect a second beam.

[0032] In some possible implementations, the first band can belong to the visible light band, and the second band can belong to the infrared light band. For example, the first band can be the 410–650 nanometer (nm) band, and the second band can be the 900–940 nm band. Another example is that the first band can be the 430–680 nm band, and the second band can be the 900–910 nm band. Yet another example is that the first and second bands can be determined based on the operating bands of the multiple detection devices involved in the system.

[0033] In some possible implementations, the outer contour of the aperture stop can be circular or elliptical; and / or, the through-hole can be circular or elliptical. For example, in the case of an elliptical through-hole, the through-hole can have different second radial dimensions in the directions of the major and minor axes of the ellipse.

[0034] In some possible implementations, the aperture stop may also include a filling portion disposed in the through hole, the surface of which may be provided with an antireflection film to improve the transmittance of light beams with wavelengths in the first and second bands when passing through the filling portion.

[0035] In this application, by providing a filling portion in the through hole of the aperture stop, it is beneficial to achieve certain specific light transmission requirements; by providing an anti-reflection film on the surface of the filling portion, the loss of the first and second waveband beams when passing through the filling portion can be reduced.

[0036] In a second aspect, an optical receiving system is provided. The optical receiving system includes an image sensor, a laser sensor, and an optical lens as described in the first aspect and any possible implementation thereof; the image sensor is used to receive a first light beam and form an image; the laser sensor is used to receive a second light beam.

[0037] Thirdly, a vehicle is also provided. This vehicle may include the optical lens described in the first aspect and any possible implementation thereof, or it may include the optical receiving system described in the second aspect and any possible implementation thereof. Attached Figure Description

[0038] Figure 1 is a schematic diagram of the structure of an optical lens provided in an embodiment of this application;

[0039] Figure 2 is a schematic diagram of an optical receiving system provided in an embodiment of this application;

[0040] Figure 3 is a schematic diagram of the structure of several aperture stops provided in the embodiments of this application;

[0041] Figure 4 is a schematic diagram of another structure of the optical receiving system provided in an embodiment of this application;

[0042] Figure 5 is a schematic diagram of another structure of the optical receiving system provided in an embodiment of this application;

[0043] Figure 6 is a schematic diagram of an imaging effect provided by an embodiment of this application. Detailed Implementation

[0044] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0045] Cameras and LiDAR, as detection devices, are widely used in various scenarios. Compared to other types of detection devices, a single type of detection device may have its own advantages, but it will inevitably have its own shortcomings. For example, ambient lighting conditions will seriously affect the image quality of a camera. Furthermore, when detecting highly reflective objects, LiDAR may suffer from high-reflectivity point cloud expansion; LiDAR is also susceptible to interference from environmental factors such as rain, fog, and dust. In a detection system, using both cameras and LiDAR, and fusing the images with point clouds, can improve the detection system's target perception accuracy, enhance its adaptability to the environment, and help it cope with complex real-world environments.

[0046] For a detection system consisting of a camera, its components may include a lens and an image sensor; the lens can gather light within the imaging spectrum to the image sensor; the image sensor can obtain image information based on the gathered light.

[0047] A detection system composed of lidar can include a transmitting unit and a receiving unit. The transmitting unit emits laser light of a specific wavelength (e.g., near-infrared). The reflected / scattered light from the object is received by the receiving unit. With the help of optical elements (e.g., lenses), the reflected light is collected by detectors such as silicon avalanche photodiodes in the receiving unit. The detectors then obtain point cloud information based on the collected reflected light. For example, near-infrared laser light can be used for detection in vehicle-mounted lidar systems.

[0048] By fusing images and point clouds, the advantages of both camera and radar sensors can be combined. However, during the fusion process, the calibration accuracy of the relative positions between different detection devices and the feature misalignment caused by differences in the characteristics of the detection devices can affect the fusion quality. If the camera and LiDAR can be fused at the optical hardware level (e.g., using the same lens), the calibration accuracy of the relative positions will be greatly improved, and feature misalignment will be reduced. This will allow the advantages of both detection devices to be better utilized, and will also have significant advantages in algorithm recognition.

[0049] However, in real-world scenarios, the optical hardware requirements of cameras and LiDAR often conflict.

[0050] For example, taking the application scenario of being installed in a vehicle as an example, for a camera, in order to ensure its reliability in high and low temperature environments, the F number of the lens can be set to around 1.6; while for a lidar, in order to achieve sufficient detection distance, the lens can be set to a smaller F number, such as around 1.2.

[0051] The F-number refers to the ratio of the lens's focal length to its entrance pupil diameter, which is the reciprocal of the relative aperture. It can also be called the aperture number (or simply aperture). The following example, with reference to Figure 1, illustrates the F-number.

[0052] For example, FIG1 is a schematic diagram of the structure of an optical lens provided in an embodiment of the present application.

[0053] Referring to Figure 1(a), lens 1 may include a lens element and an aperture stop, allowing light entering the lens to converge onto the focal plane. In this example, the focal length and entrance pupil diameter of lens 1 can be as shown in Figure 1(a), and the ratio of the focal length to the entrance pupil diameter is the F-number of the lens. In other implementations, a lens may also include multiple lens elements and / or multiple aperture stops. When a lens includes multiple lens elements, the focal length of the lens can be calculated from the focal lengths of the multiple lens elements; when a lens includes multiple aperture stops, the entrance pupil diameter of the lens can be calculated based on the parameters of the multiple aperture stops.

[0054] Referring to Figure 1(b), aperture stops #1 to #3 can have the same outer diameter; among the three aperture stops shown in Figure 1(b), the entrance pupil diameter gradually decreases from left to right. For example, assuming that aperture stops #1 to #3 can all be used in lens 1, if the aperture stop used in lens 1 is changed from aperture stop #1 to aperture stop #3 while the focal length of lens 1 remains unchanged, the aperture of the lens will become smaller, and the F-number of the lens will become larger.

[0055] For vehicle cameras and LiDAR, their different requirements for F-number make it difficult to use the same lens to simultaneously acquire images and point clouds; consequently, it is difficult to fully obtain the fusion benefits of images and point clouds using the same lens.

[0056] In view of this, embodiments of this application provide an optical lens and an optical receiving system that can use the same lens to meet the different F-number requirements of different detection devices, and can realize the fusion of lidar and camera at the optical hardware level.

[0057] For example, Figure 2 is a schematic diagram of a system architecture provided in an embodiment of this application.

[0058] As shown in Figure 2, the optical receiving system 10 may include an optical lens 200, and sensors 110 and 120. Sensors 110 and 120 are different types of sensors. For example, sensors 110 and 120 may be used to acquire image information and point cloud information, respectively.

[0059] In one embodiment, sensor 110 can be an image sensor. For example, a complementary metal oxide semiconductor (CMOS) image sensor, abbreviated as CIS. CIS can use color filter arrays of types such as red-green-blue (RGB) and red-green-green-blue (RGGB) to acquire images.

[0060] In another embodiment, sensor 120 can be a laser sensor. For example, a single-photon avalanche diode (SPAD) or a multi-pixel photon counter (MPPC) can be used. As another example, in one instance, the center wavelength of the laser used by sensor 120 can be 905 nm, and the operating wavelength range can be 900 nm to 910 nm. In some possible implementations, the center wavelength of the laser used by sensor 120 can also be other values, such as 1550 nm.

[0061] The optical lens 200 may include a lens assembly, an aperture stop 260, and a beam splitter 270.

[0062] The lens assembly can be used to receive and transmit a first light beam with a wavelength in a first band and a second light beam with a wavelength in a second band. The first band can be any band; the second band can be any band different from the first band. For example, the first band can be the visible light band, and the second band can be the near-infrared light band. Another example is that the first band can be a band from 410 nm to 680 nm, and the second band can be a band from 900 nm to 940 nm.

[0063] For example, the optical lens 200 may include one or more lens assemblies; each lens assembly may include at least one lens. For instance, as shown in FIG2, the optical lens 200 may include lens assembly 210 and lens assembly 220; an aperture stop 260 may be disposed between lens assemblies 210 and 220; lens assembly 210 may include lenses 211 to 21n (n is a positive integer). As another example, in some embodiments, the optical lens 200 may include lens assembly 220 but not lens assembly 210. That is, the lens assemblies in the optical lens 200 may be disposed after the aperture stop 260; these lens assemblies are closer to the image side of the optical lens 200 than the aperture stop 260. As yet another example, in some embodiments, the optical lens 200 may include lens assembly 210 but not lens assembly 220. That is, the lens assemblies in the optical lens 200 may be disposed before the aperture stop 260; these lens assemblies are closer to the object side of the optical lens 200 than the aperture stop 260.

[0064] The aperture stop 260 may include an aperture portion having a first radial dimension and a through-hole having a second radial dimension. The aperture portion restricts the passage of light beams with wavelengths in a first band and transmits light beams with wavelengths in a second band; the through-hole allows both light beams with wavelengths in the first and second bands to pass through. For example, the aperture portion may restrict the transmission of light beams in the first band by absorption or reflection. Alternatively, the cutoff rate of the aperture portion for light beams in the first band may be greater than 90%, such as 95%, to effectively restrict the transmission of light beams in the first band.

[0065] For example, the outer contour of the aperture stop 260 can be circular, and the through hole can be a circular through hole. For instance, the aperture stop 260 can be disc-shaped, with a circular through hole at its center; the portion of the disc excluding the circular hole can constitute the aperture stop portion of the aperture stop 260. In this case, the diameter of the circular hole can correspond to a second radial dimension, and the outer diameter of the disc can correspond to a first radial dimension.

[0066] For example, the cutoff wavelength of the aperture stop can be selected / designed based on the first and second wavelength bands. In one example, assuming the first wavelength band is 410nm to 680nm and the second wavelength band is 910nm to 940nm, the cutoff wavelength of the aperture stop can be selected / designed between 680nm and 910nm. For example, the cutoff wavelength of the aperture stop 260 can be 700nm, 750nm, 800nm, 880nm, etc.

[0067] Furthermore, assuming that the aperture stop 260 can restrict the passage of light with wavelengths below 700 nm while allowing light with wavelengths above 700 nm to pass through, then due to the blocking effect of the aperture stop, light in the 410 nm to 680 nm band can only pass through the aperture stop via the through-hole; while for the 910 nm to 940 nm band, these light rays can not only pass through the aperture stop via the through-hole but also be transmitted through the aperture stop via the aperture stop portion.

[0068] For example, the aperture portion may include a transparent substrate. The transparent substrate may be glass.

[0069] In some embodiments, the transparent substrate can be made of a material with light-filtering capabilities; correspondingly, the transparent substrate itself can have light-filtering capabilities, or even the transparent substrate alone can meet the light transmission requirements of the aperture portion. For example, the aperture portion of the aperture stop 260 can be made of a plastic material; this plastic material can absorb light of the first wavelength band and allow light of the second wavelength band to pass through.

[0070] In some embodiments, the transparent substrate itself may not have a filtering function. To meet the light transmission requirements of the aperture portion (e.g., restricting the transmission of a first-wavelength beam while allowing the transmission of a second-wavelength beam), the aperture portion may further include a filter film disposed on the transparent substrate; for ease of distinction, this is referred to as the first filter film. For example, to meet the light transmission requirements of the aperture portion, one or more filter films may be disposed on the surface of the transparent substrate, and these filter films may correspond to the first filter film. For another example, the first filter film may allow the transmission of a second-wavelength beam while restricting the transmission of a first-wavelength beam; even if the transparent substrate itself does not have a filtering function, the light transmission requirements of the aperture portion can be met by disposing of the first filter film on its surface.

[0071] In this embodiment, by setting a filter film on the surface of the transparent substrate, it is beneficial to flexibly adjust the light transmission performance of the aperture section, which is beneficial to match the usage requirements in different scenarios.

[0072] In some possible implementations, to meet certain light transmission requirements, the aperture section may also include other types of optical films, such as anti-reflective films, disposed on the transparent substrate.

[0073] The beam splitter 270 can be used to separate the first beam and the second beam. For example, after separating the first beam and the second beam, the beam splitter 270 can emit the first beam and the second beam along different optical paths so that the sensors 110 and 120 can receive the corresponding beams.

[0074] For example, the beam splitter 270 can be a wavelength beam splitter, such as a dichroic mirror. A dichroic mirror is an optical device that has different reflectivity and transmittance properties for light of different wavelengths, and can also be called a dichroic beam splitter, dichroic filters, dichroic beam splitter, etc.

[0075] In one example, a certain dichroic mirror has low reflectivity in the wavelength range below 750 nm and high reflectivity in the wavelength range above 800 nm. That is, most light with wavelengths below 750 nm is transmitted through the dichroic mirror, while most light with wavelengths above 800 nm is reflected. Assuming the first wavelength band is 410 nm to 680 nm and the second wavelength band is 910 nm to 940 nm, when using this dichroic mirror, most of the light beam in the first wavelength band will be transmitted through the mirror, while most of the light beam in the second wavelength band will be reflected.

[0076] In another example, the beam splitter 270 may include one or more of the following: a prism (i.e., a beam splitter prism), an optical plate (i.e., a beam splitter plate), or a superlens.

[0077] In some possible implementations, the beam-splitting element 270 can be a beam-splitting prism. The beam-splitting prism can include multiple emitting surfaces; it can emit a beam with a wavelength in a first wavelength band from one of its emitting surfaces, which can be referred to as the first emitting surface for easy distinction; it can also emit a beam with a wavelength in a second wavelength band from another emitting surface, which can be referred to as the second emitting surface for easy distinction. The beam-splitting prism may also include an incident surface for receiving beams with wavelengths in the first and second wavelength bands.

[0078] Since beam splitters have low requirements for the back focus of the lens, in this embodiment, by using a beam splitter, the back focus of the optical lens can be designed to be relatively short, which can save space and help the miniaturization of the optical receiving system. Moreover, since the beam splitter has low requirements for the incident angle of the beam, using a beam splitter can reduce the difficulty of optical path design.

[0079] In some possible implementations, a filter film can be placed on the surface of the beam splitter to meet certain light transmission requirements. For example, one or more filter films can be placed on the first light-emitting surface to restrict the transmission of light beams with wavelengths in the second band; for ease of distinction, this filter film can be called the second filter film. As another example, one or more filter films can be placed on the second light-emitting surface to restrict the transmission of light beams with wavelengths in the first band; for ease of distinction, this filter film can be called the third filter film. Furthermore, when the beam splitter's own beam splitting performance is poor, the beam splitting effect of the system can be guaranteed by setting the second and third filter films.

[0080] Assume the first band is the visible light band and the second band is the near-infrared light band. The following description, in conjunction with Figure 2, illustrates the operation of the optical receiving system 10.

[0081] Since the aperture stop 260 does not restrict the transmission of near-infrared light, in system 10 shown in Figure 2, when near-infrared light emitted from lens assembly 210 passes through the aperture stop 260, part of it can propagate to lens assembly 220 through the through-hole, while the other part can be transmitted through the aperture stop. However, due to the restriction effect of the aperture stop on visible light, visible light emitted from lens assembly 210 can be considered to only be able to propagate to lens assembly 220 through the through-hole when passing through the aperture stop 260. The visible light and near-infrared light emitted from lens assembly 220 can be converged to the corresponding sensors 110 and 120 respectively by the beam splitter 270.

[0082] In this embodiment, on the one hand, the two beams of light in both bands pass through the same lens assembly during their propagation within the lens 200, and thus can correspond to the same focal length. On the other hand, since the aperture stop restricts the propagation of the first beam, the first and second beams can correspond to different entrance pupil diameters. Therefore, the lens can have different F-numbers in the first and second bands, thereby accommodating the different F-number requirements of cameras and LiDAR. Furthermore, by using a beam splitter to separate the two different beams, the corresponding sensors can receive the beams of the two different bands separately.

[0083] For example, the entrance pupil diameter of the optical lens in the first band may be determined according to the second radial dimension, and the entrance pupil diameter of the optical lens in the second band may be determined according to the first radial dimension.

[0084] For example, the optical lens 200 may have only one aperture stop, namely aperture stop 260. In this case, in the first band, the entrance pupil diameter of the optical lens may be the second radial size; while in the second band, the entrance pupil diameter of the lens may be the first radial size.

[0085] For example, in the optical lens 200, multiple aperture stops can be provided to obtain the desired entrance pupil diameter; that is, in addition to aperture stop 260, the lens 200 can also be provided with other aperture stops (for example, provided in front of the lens assembly 210). In this case, based on the second radial dimension and the parameters of other aperture stops, the entrance pupil diameter of the lens in the first band can be determined; the entrance pupil diameter of the lens in the second band can be determined based on the first radial dimension and the parameters of other aperture stops.

[0086] For example, the optical lens may have a first F-number in a first band and a second F-number in a second band. The first F-number can be determined based on the second radial dimension and the focal length of the lens assembly; the second F-number can be determined based on the first radial dimension and the focal length of the lens assembly.

[0087] In some possible implementations, the first F-number can be greater than or equal to 1.2 and less than 3.0; the second F-number can be greater than or equal to 1.0 and less than 2.0; and the first F-number can be greater than the second F-number.

[0088] Vehicle-mounted LiDAR can use near-infrared light for detection; vehicle-mounted cameras can use visible light for imaging. For LiDAR, to achieve better detection of distant targets, it is often desirable to use lenses with a smaller f-number (e.g., 1.0–2.0) to increase the amount of light entering the lens. For cameras, although using lenses with a smaller f-number can increase the amount of light entering the lens and improve image quality in nighttime scenes, a smaller f-number will result in a more pronounced background blur effect. Moreover, considering the requirements for high and low temperature adaptability and reliability, lenses with f-numbers of 1.0–3.0 are preferable.

[0089] Assume the first band is the visible light band and the second band is the near-infrared light band. To accommodate the different F-number requirements of cameras and LiDAR, in one example, the lens 200 can be designed with an F-number of 1.6 in the visible light band and an F-number of 1.2 in the near-infrared light band.

[0090] In this embodiment of the application, by setting the aperture stop, the first F number of the optical lens 200 can be set within the range of 1.2 to 3.0, and the second F number can be set within the range of 1.0 to 2.0, thereby better balancing the optical hardware requirements of the camera and the lidar.

[0091] The structure and operation of the optical lens 200 have been described above with reference to Figure 2. The structure of the aperture stop 260 will be described below with reference to Figure 3.

[0092] For example, Figure 3 is a schematic diagram of the structure of several aperture stops provided in the embodiments of this application.

[0093] In some possible implementations, the outer contour of the aperture stop and its through-hole can both be circular. For example, as shown in aperture stops 300 and 400 in Figures 3(a) and (e), their outer diameter can be denoted as d1, and their center can have a through-hole with an inner diameter of d2 and a thickness of h. In this case, d1 can correspond to the first radial dimension mentioned above, and d2 can correspond to the second radial dimension.

[0094] In one embodiment, as shown in Figure 3(a), the aperture stop 300 can be disc-shaped, with a through hole 320 in the central region of the disc, and the portion of the disc other than the through hole 320 forming the aperture stop portion 310 of the aperture stop 300. Unlike the aperture stop 260 shown in Figure 2, the sidewall of the through hole 320 can be provided with a chamfered surface 321. For example, the angle between the chamfered surface 321 and the end face of the aperture stop 300 can be 30 degrees, 45 degrees, or other angles. For example, to eliminate stray light, the chamfered surface 321 can be frosted, or corrugated protrusions can be provided on the chamfered surface 321. For example, an matting material can be provided on the chamfered surface 321 to eliminate stray light. For example, an abrasive material or a frosted finish can be applied to the projection area of ​​the oblique cut surface 321 on the end face of the aperture stop (e.g., the projection along the thickness direction of the aperture stop) to reduce stray light interference with the system.

[0095] In some other embodiments, the outer contour of the aperture stop and the through hole may also be other shapes.

[0096] For example, as shown in Figures 3(b) and (d), the outer contour of the aperture stop can be elliptical, with its major and minor axes denoted as a1 and b1, respectively. In this case, a1 can correspond to the first radial dimension along the major axis of the ellipse; b1 can correspond to the first radial dimension along the minor axis of the ellipse; and in directions other than the major and minor axes, the first radial dimension can be between b1 and a1. Accordingly, the second F-number of the optical lens can have different values ​​in different directions.

[0097] For example, as shown in Figures 3(c) and (d), the through-hole can be elliptical, with its major and minor axes denoted as a2 and b2, respectively. In this case, a2 corresponds to the second radial dimension along the major axis of the ellipse; b2 corresponds to the second radial dimension along the minor axis; and in directions other than the major and minor axes, the second radial dimension can be between b2 and a2. Accordingly, the first F-number of the optical lens can have different values ​​in different directions.

[0098] In some possible implementations, the aperture stop may also include a filling portion disposed in the through hole.

[0099] For example, referring to Figure 3(e), similar to aperture stop 300, aperture stop 400 can be disc-shaped; aperture stop 400 can include an aperture portion 410, and aperture stop 400 can be provided with a through hole 420. Unlike aperture stops 260 and 300, aperture stop 400 can also include a filling portion 430 disposed in the through hole 420.

[0100] For example, the filling portion 430 can meet certain specific light transmission requirements. For instance, the filling portion 430 can absorb or reflect ultraviolet light; by providing the filling portion 430, the light beam in the ultraviolet band can be restricted from passing through the through-hole portion of the aperture stop. As another example, the surfaces 431 and / or 432 of the filling portion 430 can be provided with an anti-reflection film to improve the transmittance of the first and second wavelength bands through the filling portion 430; the anti-reflection film can also be called an anti-reflection (AR) film. As yet another example, the filling portion 430 can be made of glass or plastic.

[0101] In some embodiments, as shown in Figures 3(a) to (e), the center of the through hole may coincide with the center of the aperture stop.

[0102] In other implementations, the center of the through hole may be offset from the center of the aperture stop; the outer contour of the aperture stop and / or the through hole may also be other regular or irregular shapes.

[0103] The structure of the aperture stop has been illustrated above with reference to Figure 3. The implementation of the optical receiving system will now be illustrated below with reference to Figures 4 and 5. The optical receiving systems 60 and 70 shown in Figures 4 and 5 can be understood as extensions or modifications of the optical receiving system 10. In Figures 4 and 5, assuming the first wavelength band is 410–650 nm and the second wavelength band is 900–940 nm, the beam splitter directs the beams with wavelengths below 700 nm and the beams with wavelengths above 700 nm along different optical paths.

[0104] For example, Figure 4 is a schematic diagram of the structure of another optical receiving system provided in an embodiment of this application.

[0105] As shown in Figure 4, the optical receiving system 60 may include a lens 600 and sensors 110 and 120. The lens 600 may include lens assemblies 610 and 620, an aperture stop 630, and a beam splitter 640. Lens assembly 610 may correspond to lens assembly 210, and lens assembly 620 may correspond to lens assembly 220; aperture stop 630 may correspond to aperture stop 260; and beam splitter 640 may correspond to beam splitter element 270.

[0106] The beam splitter 640 may include a surface 641 facing the sensor 110 and a surface 642 facing the sensor 120, as shown in FIG4. For example, through the beam splitting effect of the beam splitter 640, light beams with wavelengths below 700nm can exit from surface 641 after passing through the beam splitter 640, while light beams with wavelengths above 700nm can exit from surface 642 after passing through the beam splitter 640.

[0107] In some implementations, the beam-splitting performance of certain beam-splitting prisms may be relatively poor. For example, through beam splitting, approximately 85% of the beam with wavelengths below 700 nm may be guided to surface 641, while the remaining 15% may be guided to surface 642. To meet the light transmission requirements, optical films can be applied to surfaces 641 and / or 642.

[0108] In one example, an infrared cutoff filter can be provided on surface 641 to allow light of the first wavelength band to pass through while blocking infrared light, including the second wavelength band, from passing through. Similarly, a filter can be provided on surface 642 to block the light beam of the first wavelength band.

[0109] In this embodiment, by setting a filter film on the light-emitting surface of the beam splitter, it is beneficial to ensure the beam splitting effect of the system.

[0110] In another example, the filter film disposed on surface 642 can be a narrowband filter film. For example, assuming that the operating wavelength of the lidar is 900nm to 940nm; accordingly, in order to adapt to the operating wavelength of the lidar, the narrowband filter film can transmit light beams in the 900nm to 940nm wavelength band and can block the passage of light beams in other wavelength bands.

[0111] In this embodiment of the application, by setting a narrowband filter film that is compatible with the operating band of the lidar, the bandwidth of the background light can be reduced, thereby improving the signal-to-noise ratio of the lidar.

[0112] In one design, the focal length of lens 600 can be 16 millimeters (mm). Aperture stop 630 can adopt a ring-shaped structure as shown in Figure 3(a), with an outer diameter of 8 mm and an inner diameter of 5.6 mm. A high-pass filter can be provided on the front surface of aperture stop 630, and an AR filter can be provided on its rear surface. This high-pass filter allows light with wavelengths greater than a certain threshold (e.g., 700 nm) to pass through, while blocking light with wavelengths less than that threshold.

[0113] With this design, lens 600 can meet the usage requirements of an F-number of 1.6 for the visible light band of 410nm to 650nm; and can meet the usage requirements of an F-number of 1.2 for the near-infrared band of 900nm to 940nm.

[0114] For example, Figure 5 is a schematic diagram of the structure of another optical receiving system provided in an embodiment of this application.

[0115] As shown in Figure 5, the optical receiving system 70 may include a lens 700 and sensors 110 and 120. The lens 700 may include lens assemblies 710 and 720, an aperture stop 730, and a dichroic mirror 740. Lens assemblies 710 and 720 may correspond to lens assemblies 210 and 220, respectively; aperture stop 730 may correspond to aperture stop 260; and dichroic mirror 740 may correspond to beam splitter 270.

[0116] For example, the dichroic mirror 740 may include a surface 741 facing the sensor 110 and a surface 742 facing the sensor 120, as shown in FIG5. In some implementations, an optical film may be provided on surface 641 and / or surface 642, depending on the light transmission requirements.

[0117] For example, through the beam-splitting effect of the dichroic mirror, light beams with wavelengths below 700 nm can exit from surface 741 after passing through dichroic mirror 740, while light beams with wavelengths above 700 nm can be directly reflected by surface 742. As another example, an infrared cutoff filter can be provided on surface 741 to allow light of the first wavelength band to pass through while blocking the transmission of infrared light, including the second wavelength band. As yet another example, a narrowband filter can be provided on surface 742 to allow light beams of the second wavelength band to pass through while restricting the passage of light beams of the first wavelength band.

[0118] For optical lenses (200, 600, 700), the imaging effect is related to the selection and design of the lens components (210, 220, 610, 620, 710, 720). The imaging effect of the lens is illustrated below with reference to Figure 6.

[0119] For example, Figure 6 shows a schematic diagram of an imaging effect.

[0120] As shown in Figure 6, the original pattern can be represented by alternating black and white bars, indicating varying densities of black and white line pairs. When observing the original pattern through a lens, it may become blurred due to lens degradation. The number of black and white line pairs appearing per unit length, i.e., the spatial frequency, can be expressed as line pairs per millimeter (lp / mm). For example, in Figure 6, the rightward portion of the original pattern shows a higher density of black and white line pairs, corresponding to a higher value per millimeter.

[0121] For optical receiving systems, higher resolution results in clearer images; systems can have different resolutions at different spatial frequencies. For example, as shown in Figure 6, the denser the black and white line pairs, the blurrier the image will be.

[0122] The resolving power of a system can be represented by its spatial frequency response (SFR). The closer the SFR is to 1, the higher the resolving power of the system; the closer the SFR is to 0, the lower the resolving power of the system.

[0123] Assume the first band is 410nm~650nm and the second band is 900nm~940nm.

[0124] In one design approach, by selecting and designing the lens components, the resolution of the optical lens 200 can meet the following requirements: in the 410nm to 650nm band, the SFR corresponding to 119lp / mm can be greater than or equal to 0.25; in the 900nm to 940nm band, the SFR corresponding to 19lp / mm can be greater than or equal to 0.7.

[0125] The optical lens has been illustrated above with reference to Figures 2 to 6.

[0126] This application also provides an optical receiving system, which may include the optical receiving system in any of the embodiments of FIG2 to FIG6.

[0127] This application also provides a detection system, which may include the optical lens or optical receiving system in any of the embodiments of Figures 2 to 6 above.

[0128] This application also provides a vehicle in which the optical receiving system may include the optical lens or optical receiving system in any of the embodiments of FIG2 to FIG6, or may include the detection system described above.

[0129] The vehicles involved in this application embodiment can be vehicles in a broad sense, including transportation vehicles (such as commercial vehicles, passenger cars, motorcycles, flying cars, trains, etc.), industrial vehicles (such as forklifts, trailers, tractors, etc.), engineering vehicles (such as excavators, bulldozers, cranes, etc.), agricultural equipment (such as lawnmowers, harvesters, etc.), amusement equipment, toy vehicles, etc. This application embodiment does not specifically limit the type of vehicle. For example, the vehicles in this application can be hybrid electric vehicles (HEV), range-extended electric vehicles (REEV), plug-in hybrid electric vehicles (PHEV), or new energy vehicles (NEV), etc.

[0130] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and other forms such as the third-person singular "comprises" and the present participle "comprising" are interpreted as open and inclusive, meaning "including, but not limited to." In the description, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this application. The illustrative representations of the foregoing terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be included in any suitable manner in any of the embodiments or examples.

[0131] The terms "first" and "second" used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0132] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0133] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0134] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0135] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0136] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0137] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An optical lens, characterized in that, The optical lens includes: a lens assembly, an aperture stop, and a beam splitter; The lens assembly is used to receive and transmit a first light beam with a wavelength in a first band and a second light beam with a wavelength in a second band. The aperture stop includes an aperture portion having a first radial dimension and a through hole having a second radial dimension; The through-hole is used to allow light beams with wavelengths in the first and second bands to pass through; The aperture portion is used to: restrict the transmission of light beams with wavelengths in the first band and transmit light beams with wavelengths in the second band; The beam splitter is used to separate the first beam and the second beam.

2. The optical lens according to claim 1, characterized in that, The entrance pupil diameter of the optical lens in the first waveband is determined based on the second radial dimension; The entrance pupil diameter of the optical lens in the second band is determined based on the first radial dimension.

3. The optical lens according to claim 1 or 2, characterized in that, The optical lens has a first F-number in the first wavelength band, and the first F-number is determined based on the second radial dimension and the focal length of the lens assembly; The optical lens has a second F-number in the second band, which is determined based on the first radial dimension and the focal length of the lens assembly.

4. The optical lens according to claim 3, characterized in that, The first F number is greater than or equal to 1.2, and the first F number is less than 3.0; The second F-number is greater than or equal to 1.0, and the second F-number is less than 2.0; The first F number is greater than the second F number.

5. The optical lens according to any one of claims 1 to 4, characterized in that, The aperture portion includes a transparent substrate, which is used to transmit light beams with wavelengths in the second band.

6. The optical lens according to claim 5, characterized in that, The transparent substrate is also used to restrict the transmission of light beams with wavelengths in the first band.

7. The optical lens according to claim 5 or 6, characterized in that, The aperture portion further includes a first filter film disposed on the surface of the transparent substrate. The first filter film is used to restrict the transmission of light beams with wavelengths in the first band and to transmit light beams with wavelengths in the second band.

8. The optical lens according to any one of claims 5 to 7, characterized in that, The transparent substrate is made of glass or plastic.

9. The optical lens according to any one of claims 1 to 8, characterized in that, The beam-splitting element includes a beam-splitting prism, and the beam-splitting prism includes a first light-emitting surface and a second light-emitting surface; The beam splitter is used to emit a light beam with a wavelength in the first band at the first emitting surface and a light beam with a wavelength in the second band at the second emitting surface.

10. The optical lens according to claim 9, characterized in that, The first light-emitting surface is provided with a second filter film, which is used to transmit light beams with wavelengths in the first band and restrict the transmission of light beams with wavelengths in the second band. The second light-emitting surface is provided with a third filter film, which is used to transmit light beams with wavelengths in the second band and restrict the transmission of light beams with wavelengths in the first band.

11. The optical lens according to any one of claims 1 to 9, characterized in that, The beam splitter includes a dichroic mirror, which transmits a light beam with a wavelength in the first band and reflects a light beam with a wavelength in the second band.

12. The optical lens according to any one of claims 1 to 11, characterized in that, The first band belongs to the visible light band, and the second band belongs to the infrared light band.

13. The optical lens according to any one of claims 1 to 12, characterized in that, The outer contour of the aperture stop is circular or elliptical; and / or, The through hole is circular or elliptical.

14. The optical lens according to any one of claims 1 to 13, characterized in that, The aperture stop further includes a filling portion disposed in the through hole, and the surface of the filling portion is provided with an anti-reflection film to improve the transmittance of light beams with wavelengths in the first band and the second band when passing through the filling portion.

15. An optical receiving system, characterized in that, The optical receiving system includes an image sensor, a laser sensor, and an optical lens as described in any one of claims 1 to 14; The image sensor is used to receive the first light beam and form an image; The laser sensor is used to receive the second beam.

16. A vehicle, characterized in that, It includes the optical lens as described in any one of claims 1 to 14, or the optical receiving system as described in claim 15.

Images