Optical scanning device and lidar

Abstract

This application relates to an optical scanning device and a lidar. The device includes a reflector, a reflector substrate, and an extinction element. The reflector is disposed on the reflector substrate, and the extinction element is positioned in front of the reflector substrate. The reflector is used to reflect incident light; the extinction element is used to reduce scattered light generated by the incident light on the reflector substrate. This device can significantly reduce scattered light inside the lidar, reduce the detection blind zone caused by stray light, and greatly improve the receiving and detection capability of the lidar.

Description

Technical Field

[0001] This application relates to the field of optical technology, and in particular to an optical scanning device and a lidar. Background Technology

[0002] With the development of lidar technology, people have increasingly higher requirements for the detection performance of lidar.

[0003] In solid-state lidar, microelectromechanical systems (MEMS) are typically used as the core scanning device. However, due to the reflective and scattering characteristics of the laser beam, disordered stray light is generated inside the lidar. Since the lidar's receiver detector is extremely sensitive, it responds to this stray light, causing the nearby return light signal to be submerged in the signal generated by the internal stray light, resulting in a large detection blind zone. Summary of the Invention

[0004] Therefore, it is necessary to provide an optical scanning device and lidar that can reduce the detection blind zone in response to the above-mentioned technical problems.

[0005] In a first aspect, embodiments of this application provide an optical scanning device, the device comprising: a reflector, a reflector substrate, and an anti-glare component; the reflector is mounted on the reflector substrate, and the anti-glare component is positioned in front of the reflector substrate;

[0006] The reflector is used to reflect incident light.

[0007] The light-reducing element is used to reduce the scattered light generated by the incident light on the reflector substrate.

[0008] In one embodiment, the light-absorbing element is an aperture, which is disposed on the front side of the reflector, and the light-transmitting aperture of the aperture is aligned with the reflector.

[0009] In one embodiment, the area of ​​the light-transmitting aperture of the aperture is greater than or equal to the area of ​​the reflector.

[0010] In one embodiment, the aperture is positioned at a predetermined height on the front of the reflector; the predetermined height is determined based on the maximum incident angle of the incident light and the radius difference between the aperture and the reflector.

[0011] In one embodiment, the surface scattering coefficient of the aperture is lower than the scattering coefficient of the front side of the reflector substrate.

[0012] In one embodiment, a light-absorbing film or a reflective film is attached to the aperture.

[0013] In one embodiment, the thickness of the aperture is less than a preset thickness threshold, which is determined by not blocking the incident light reflected by the reflector.

[0014] In one embodiment, the front side of the reflector substrate is provided with an anti-light layer, which is used to reduce the scattering of the incident light by the reflector substrate.

[0015] In one embodiment, the matting layer is a reflective layer or a light-absorbing layer.

[0016] Secondly, embodiments of this application provide a lidar, which includes the optical scanning device described in any of the above embodiments.

[0017] The aforementioned optical scanning device and lidar include a reflector, a reflector substrate, and an extinction element. The reflector is mounted on the reflector substrate and is used to reflect incident light. The extinction element is placed in front of the reflector substrate and can reduce the incident light falling on the reflector substrate, thereby reducing the scattered light generated on the reflector substrate. At the same time, the scattering coefficient of the surface of the extinction element is lower than that of the scattering system on the front of the reflector substrate, which greatly reduces the scattered light inside the lidar, reduces the detection blind zone caused by stray light, and greatly improves the receiving and detection capability of the lidar. Attached Figure Description

[0018] Figure 1 A schematic diagram of the structure of an optical scanning device provided in one embodiment;

[0019] Figure 2 This represents the main optical signal generation path in a lidar system.

[0020] Figure 3 This is a schematic diagram showing the incident light spot extending beyond the reflector in one embodiment;

[0021] Figure 4 A schematic diagram showing the predetermined height.

[0022] Explanation of reference numerals in the attached figures:

[0023] Mirror: 100; Mirror substrate: 200;

[0024] Matte component: 300; Matte layer: 400. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0026] Figure 1 A schematic diagram of the structure of an optical scanning device provided in one embodiment is shown below. Figure 1 As shown, the device includes: a reflector 100, a reflector base 200, and an extinction element 300; the reflector 100 is mounted on the reflector base 200, and the extinction element 300 is positioned in front of the reflector base 200; the reflector 100 is used to reflect incident light; the extinction element 300 is used to reduce the scattered light generated by the incident light on the reflector base 200.

[0027] It should be noted that you can refer to Figure 2 As shown, Figure 2 This describes the main optical signal generation path in a lidar system. The laser collimation system is a laser emission system with a small emission divergence angle, consisting of a laser source and a collimating optical system. Optionally, the laser source can include, but is not limited to, solid-state laser sources, gas laser sources, semiconductor laser sources, liquid laser sources, chemical laser sources, fiber laser sources, and free-electron laser sources. Optionally, the collimating optical system can include, but is not limited to, combinations of spherical mirror optical systems, cylindrical mirror optical systems, aspherical optical systems, folded hybrid optical systems, and graded-index composite optical systems. The aforementioned optical scanning device can be a microelectromechanical system (MEMS) or other galvanometer systems; this embodiment does not limit this. Typically, the lidar emits an optical signal through the laser collimation system. After passing through the optical scanning device, the optical signal reaches the target object, and this portion of the optical signal is reflected back to the lidar's receiving system by the target object; additionally, some of the optical signal is scattered within the optical scanning device. For example... Figure 3 As shown, when the light signal enters the light scanning device, most of the light signal is concentrated on the reflector 200 and reflected to the target object. However, part of the light signal that protrudes from the reflector 100 is scattered by the reflector substrate 200, exhibiting a high-order cosine scattering characteristic. The scattered light is captured by the receiving system, causing the receiving system to form an internally scattered signal response. This causes the receiving system to saturate prematurely and become unable to respond to the nearby return light signal. The return light signal is submerged in the signal generated by the internal stray light, creating a detection blind zone.

[0028] Specifically, the aforementioned optical scanning device includes a reflector 100, a reflector substrate 200, and an extinction element 300. The reflector 100 is mounted on the reflector substrate 200, and the extinction element 300 is positioned in front of the reflector substrate 200. Optionally, the extinction element 300 can be attached to the front of the reflector substrate 200 or positioned at a certain distance in front of the reflector substrate 200; this embodiment does not limit this. When an optical signal is incident on the optical scanning device, because the extinction element 300 is positioned in front of the reflector 200, most of the incident light is reflected after entering the reflector 100. A small portion of the incident light first passes through the extinction element 300. The extinction element 300 can reduce or even nearly eliminate some of the incident light that does not fall on the reflector 100, thereby greatly reducing the amount of incident light that would originally fall on the reflector substrate 200. Therefore, it significantly reduces the scattered light generated by the reflector substrate 200 on the incident light.

[0029] In this embodiment, the optical scanning device includes a reflector, a reflector substrate, and an extinction element. The reflector is mounted on the reflector substrate to reflect incident light. The extinction element is placed in front of the reflector substrate and can reduce the scattered light generated on the reflector substrate by reducing the incident light falling on it. At the same time, the scattering coefficient of the surface of the extinction element is lower than that of the scattering system on the front of the reflector substrate, which greatly reduces the scattered light inside the lidar, reduces the detection blind zone caused by stray light, and greatly improves the receiving and detection capability of the lidar.

[0030] Optionally, see [link to relevant documentation] Figure 1 As shown, based on the above embodiment, the light-absorbing element 300 can be an aperture, and the aperture is disposed on the front of the reflector 100, and the light-transmitting hole of the aperture is aligned with the reflector 100.

[0031] Specifically, since the aperture is set on the front side of the reflector 100, i.e. the incident side, the incident light rays are first selected by the aperture before entering the reflector 100. Since the light aperture of the aperture is aligned with the reflector 100, the part of the incident light rays that falls into the light aperture of the aperture can reach the reflector 100, and the rest of the incident light rays that fall on the aperture can be prevented from falling on the reflector base 200 by the action of the aperture.

[0032] In this embodiment, by placing the aperture on the front of the reflector and aligning the aperture with the reflector, the light signal falling on the reflector substrate is greatly reduced, thereby reducing the scattered light generated by the incident light on the reflector substrate. This greatly reduces the scattered light inside the optical scanning device, significantly reducing the detection blind zone caused by stray light and greatly improving the receiving and detection capability of the lidar.

[0033] Optionally, the surface scattering coefficient of the aforementioned aperture is lower than the scattering coefficient of the front surface of the reflector substrate 200. By setting the aperture to have a surface scattering coefficient lower than that of the front surface of the reflector substrate 200, the scattering of incident light falling on the aperture can be greatly reduced compared to the scattering degree of incident light by the reflector substrate 200. This significantly reduces scattered light, thereby greatly reducing the scattered light inside the lidar, reducing the detection blind zone caused by stray light, and greatly improving the receiving and detection capability of the lidar.

[0034] Optionally, an absorbing film or a reflective film can be attached to the aperture to reduce the scattering coefficient of the aperture surface. Objects typically exhibit three responses to light signals: incident, reflected, and scattered. Due to energy conservation, scattering characteristics can be reduced by increasing absorption and reflection. Therefore, by attaching an absorbing film to the aperture surface, more incident light can be absorbed, thus significantly reducing scattered light; or by attaching a reflective film to the aperture surface, more light signals can be reflected. Since reflection can be directional, the light signal can be reflected in a direction that does not affect the receiving system, thereby significantly reducing scattered light. In this embodiment, by attaching an absorbing film to the aperture to enhance the absorption of incident light and reduce scattering, or by attaching a reflective film to the aperture to enhance the reflection of incident light and reduce scattering, the scattering coefficient of the aperture surface is reduced, the detection blind zone caused by stray light is reduced, and the receiving and detection capability of the lidar is greatly improved.

[0035] Optionally, the thickness of the aforementioned aperture is less than a preset thickness threshold, which is determined by ensuring that the incident light reflected by the mirror is not blocked.

[0036] Specifically, the thickness of the aforementioned aperture needs to be less than a preset thickness threshold. Since an excessively thick aperture can interfere with the incident light and affect the receiving performance of the receiving system, a thickness threshold can be set to ensure that the aperture thickness is less than the threshold, thereby preventing the aperture from blocking the incident light reflected by the mirror due to excessive thickness. In particular, the thickness of the aforementioned aperture should be as small as possible to minimize its impact on the incident light.

[0037] Optionally, based on the above embodiments, the area of ​​the light-transmitting aperture of the aperture is greater than or equal to the area of ​​the reflector 100.

[0038] Specifically, the area of ​​the aperture of the diaphragm can be greater than or equal to the area of ​​the reflector 100. It can be slightly larger than or equal to the area of ​​the reflector 100. By setting the area of ​​the aperture of the diaphragm to be greater than or equal to the area of ​​the reflector, it ensures that as much incident light as possible falls on the reflector, while minimizing the scattering of incident light by the reflector substrate. This ensures the optical scanning device's response to the optical signal while reducing the detection blind zone caused by stray light, thus greatly improving the receiving and detection capability of the lidar.

[0039] Optionally, based on the above embodiment, the aperture is set on the front of the reflector 100 at a preset height; the preset height is determined based on the maximum incident angle of the incident light and the radius difference between the aperture and the reflector.

[0040] Specifically, when incident light strikes the reflector 100, there will be an angle between the incident light and the plane of the reflector. If the angle is too large, the light may not be able to enter the reflector 100 and instead fall onto the reflector base 200. To ensure that the incident light rays are blocked by the aperture as little as possible, the height of the aperture can be determined based on the maximum incident angle of the incident light rays, the radius difference between the aperture and the reflector 100. (See [reference needed]). Figure 4 As shown, Figure 4 In this equation, d represents the difference between the radius of the aperture and the radius of the reflector 100, α represents the maximum incident angle of the incident light, and h represents the height of the aperture, which is the difference in distance between the front of the aperture and the reflector 100. Optionally, the height of the aperture can be determined by calculating using the formula h = dtanα or a variation of this formula.

[0041] In this embodiment, by setting the aperture at a predetermined height on the front of the reflector, since the predetermined height is determined based on the maximum incident angle of the incident light and the radius difference between the aperture and the reflector, it can ensure that the incident light passes through the light-transmitting hole of the aperture to the maximum extent and is directed toward the reflector, so that the incident light can be reflected to the maximum extent, thereby improving the light utilization rate and the radar detection capability.

[0042] Optionally, based on the above embodiments, an anti-light layer 400 may be attached to the front side of the reflector substrate 200. The anti-light layer 400 is used to reduce the scattering of incident light by the reflector substrate 200.

[0043] Specifically, since the aperture cannot completely eliminate the incident light illuminating the reflector substrate 200, an extinction layer 400 can be attached to the front surface of the reflector substrate 200. This extinction layer can further reduce the scattering of incident light by the reflector substrate 200. Optionally, the extinction layer 400 can be a reflective layer or a light-absorbing layer. When the extinction layer 400 is a reflective layer, it can reduce the scattering characteristics by increasing the reflection characteristics of incident light; when the extinction layer 400 is a light-absorbing layer, it can reduce the scattering characteristics by increasing the absorption characteristics of incident light. Therefore, the scattering of incident light by the reflector substrate can be further reduced, the detection blind zone caused by stray light is reduced, and the receiving and detection capability of the lidar is greatly improved.

[0044] In one embodiment, a lidar is also provided, the lidar comprising any of the optical scanning devices described in the above embodiments.

[0045] The technical principles and effects involved in lidar are the same as those of the aforementioned optical scanning device, and will not be repeated here.

[0046] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An optical scanning device, characterized in that, The device includes: a reflector, a reflector base, and an anti-glare component; the reflector is mounted on the reflector base, and the anti-glare component is positioned in front of the reflector base. The reflector is used to reflect incident light. The extinction element is used to reduce the scattered light generated by the incident light on the reflector substrate; the extinction element is an aperture, which is disposed on the front side of the reflector, and the light-passing aperture of the aperture is aligned with the reflector; the surface scattering coefficient of the aperture is lower than the scattering coefficient of the front side of the reflector substrate; the aperture is disposed on the front side of the reflector at a predetermined height; the predetermined height is determined by the following formula: h=dtanα Where h is the fixed height of the aperture, d is the radius difference between the aperture and the mirror, and α is the maximum incident angle of the incident light. A reflective film is attached to the aperture, and the reflective film is configured to reflect light in a direction that does not affect the receiving system; the thickness of the aperture is less than a preset thickness threshold, which is determined by not blocking the incident light reflected by the reflector.

2. The optical scanning device according to claim 1, characterized in that, The area of ​​the light-transmitting aperture of the aperture is greater than or equal to the area of ​​the reflecting mirror.

3. The optical scanning device according to claim 1, characterized in that, The light-absorbing film is attached to the aperture.

4. The optical scanning apparatus according to any one of claims 1 to 3, characterized in that, The front side of the reflector substrate is covered with an anti-light layer, which is used to reduce the scattering of the incident light by the reflector substrate.

5. The optical scanning device according to claim 4, characterized in that, The matting layer is either a reflective layer or a light-absorbing layer.

6. A lidar, characterized in that, The lidar includes the optical scanning device as described in any one of claims 1 to 5.

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