A lidar black mirror
By employing a multi-layer Si and SiO2 film structure and a tempered optical glass substrate on the lidar window lens, the problems of high coating cost and poor color matching are solved, achieving high laser transmittance and improved lens blackness, thus enhancing safety and overall aesthetics.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- FOCTEK PHOTONICS INC
- Filing Date
- 2023-02-27
- Publication Date
- 2026-05-15
AI Technical Summary
The coating cost of existing lidar window lenses is high, and the mirror effect and color matching are poor, which cannot meet the overall vehicle styling and safety requirements.
Employing a multi-layered Si and SiO2 film structure combined with a tempered optical glass substrate, high laser transmittance and visible light absorption are achieved through traditional vacuum coating equipment, ensuring the lens's blackness and strength.
It reduces coating costs, improves lens blackness and strength, reduces visible light reflection, and enhances safety and compatibility with vehicle paint.
Smart Images
Figure CN116299819B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of vehicle-mounted equipment technology, and specifically to a black lens for lidar. Background Technology
[0002] With the development of autonomous driving technology, cars equipped with driver assistance systems are now ubiquitous on the road. LiDAR is an essential component for achieving Level 3 and higher autonomous driving capabilities; we can think of it as the car's eyes. LiDAR can perceive road conditions more accurately, and the computer system can issue relevant commands to the vehicle based on the information detected by the radar, enabling the car to achieve more advanced driver assistance functions. Automotive-grade LiDAR transmits and receives laser light, primarily with wavelengths of 905 nanometers and 1550 nanometers.
[0003] The window lens of a lidar is usually placed on the outermost side of the lidar imaging system to protect the lidar system. In order to improve the overall optical performance and effective application, the lidar window lens usually needs to be coated to maintain a high transmittance of the emitted laser wavelength. At the same time, for the aesthetics of the overall vehicle design, there are also certain requirements for the color of the window lens. Generally, black window lenses are easy to match with various colors.
[0004] Currently, LiDAR lenses typically use silicon hydride as a raw material for coating on glass. While silicon hydride achieves high transmittance in the aforementioned laser wavelengths, it requires sophisticated coating equipment, necessitating expensive magnetron sputtering machines. This increases coating costs and the overall cost of manufacturing the LiDAR window lens. Furthermore, multilayer films coated with silicon hydride often exhibit high reflectivity in the visible light spectrum, resulting in a mirror-like effect that displays or reflects certain colors, such as blue or blue-green, reducing compatibility with the overall vehicle paint. Using black glass or black plastic directly as the LiDAR lens is also unsuitable, as these materials are difficult to temper, compromising strength and safety. Summary of the Invention
[0005] This invention provides a black lens for lidar. The black glass lens of this invention can not only transmit high light intensity to 1550 nanometer lasers, but also reduce the reflectivity of the visible light band and make the reflectivity of the visible light band more uniform, thus ensuring the blackness of the lens and making it able to match the overall paint of the vehicle.
[0006] This invention is achieved through the following technical solution:
[0007] A black lens for lidar includes an optical glass substrate and a film layer deposited on both sides of the optical glass substrate. The film layer consists of a first Si layer, a first SiO2 layer, a second Si layer, a second SiO2 layer, a third Si layer, a third SiO2 layer, a fourth Si layer, a fourth SiO2 layer, a fifth Si layer, and a fifth SiO2 layer, arranged sequentially from the inside to the outside of the surface of the optical glass substrate.
[0008] Specifically, in the film layers of the present invention, the thickness of the first Si layer is 9.92-10.32 nm; the thickness of the first SiO2 layer is 22.37-23.28 nm; the thickness of the second Si layer is 223.10-232.21 nm; the thickness of the second SiO2 layer is 202.34-210.60 nm; the thickness of the third Si layer is 15.40-16.02 nm; the thickness of the third SiO2 layer is 14.09-14.67 nm; the thickness of the fourth Si layer is 197.91-205.99 nm; the thickness of the fourth SiO2 layer is 15.75-16.39 nm; the thickness of the fifth Si layer is 8.74-9.10 nm; and the thickness of the fifth SiO2 layer is 83.45-86.85 nm.
[0009] In preferred embodiment one, the thickness of the first Si layer is 10.12 nm; the thickness of the first SiO2 layer is 22.83 nm; the thickness of the second Si layer is 227.65 nm; the thickness of the second SiO2 layer is 206.47 nm; the thickness of the third Si layer is 15.71 nm; the thickness of the third SiO2 layer is 14.38 nm; the thickness of the fourth Si layer is 201.95 nm; the thickness of the fourth SiO2 layer is 16.07 nm; the thickness of the fifth Si layer is 8.92 nm; and the thickness of the fifth SiO2 layer is 85.15 nm.
[0010] In preferred embodiment two, the thickness of the first Si layer is 10.32 nm; the thickness of the first SiO2 layer is 23.28 nm; the thickness of the second Si layer is 232.21 nm; the thickness of the second SiO2 layer is 210.60 nm; the thickness of the third Si layer is 16.02 nm; the thickness of the third SiO2 layer is 14.67 nm; the thickness of the fourth Si layer is 205.99 nm; the thickness of the fourth SiO2 layer is 16.39 nm; the thickness of the fifth Si layer is 9.10 nm; and the thickness of the fifth SiO2 layer is 86.85 nm.
[0011] In preferred embodiment three, the thickness of the first Si layer is 9.92 nm; the thickness of the first SiO2 layer is 22.37 nm; the thickness of the second Si layer is 223.10 nm; the thickness of the second SiO2 layer is 202.34 nm; the thickness of the third Si layer is 15.40 nm; the thickness of the third SiO2 layer is 14.09 nm; the thickness of the fourth Si layer is 197.91 nm; the thickness of the fourth SiO2 layer is 15.75 nm; the thickness of the fifth Si layer is 8.74 nm; and the thickness of the fifth SiO2 layer is 83.45 nm.
[0012] Furthermore, the optical glass substrate is a tempered optical glass substrate.
[0013] Compared with the prior art, the present invention has the following advantages:
[0014] The black glass sheet for lidar of the present invention not only has high transmittance for 1550 nm lasers, but also reduces the reflectivity of the visible light band and makes the reflectivity of the visible light band more consistent, ensuring the blackness of the window lens so that it can match the overall paint of the car.
[0015] Specifically, it utilizes the relatively inexpensive silicon material's absorption of visible light and transmission of near-infrared light, satisfying both the high transmittance requirements for laser wavelengths and the absorption of visible light to reduce noise interference. Therefore, by directly using a combination of high-refractive-index silicon and low-refractive-index silicon dioxide film materials, the coating of the black window of the lidar can be achieved using traditional vacuum coating equipment.
[0016] Furthermore, to increase the protective strength of the window lens, the optical glass material is tempered. The tempered glass after tempering is several times stronger than ordinary glass, with a bending strength 3-5 times that of ordinary glass and an impact strength 5-10 times that of ordinary glass. This increased strength also improves safety. Moreover, its increased load-bearing capacity improves its brittleness. Even if tempered glass breaks, it will shatter into small fragments without sharp edges, greatly reducing the risk of injury to the human body. The tempered glass's resistance to rapid heating and cooling is 2-3 times better than that of ordinary glass, and it can generally withstand temperature differences of over 150°C, which has a significant effect on preventing thermal cracking.
[0017] Specifically, the black glass sheet for lidar described in this invention has an average reflectivity of 2% for a laser wavelength of 1550nm with an incident angle of 0-60 degrees, ensuring efficient laser transmission; for visible light wavelengths of 400-700nm, the reflectivity is relatively consistent within the band, with an average reflectivity of 5.7% for an incident angle of 0 degrees. Attached Figure Description
[0018] Figure 1 This is the reflectance spectrum curve of Example 1.
[0019] Figure 2 This is the reflectance spectrum curve of Example 1.
[0020] Figure 3 This is the reflectance spectrum curve of Example 1. Detailed Implementation
[0021] The present invention will be further described below with reference to specific embodiments. Example 1
[0022] A black lens for lidar includes an optical glass substrate and a film layer deposited on both sides of the optical glass substrate. The film layer consists of a first Si layer, a first SiO2 layer, a second Si layer, a second SiO2 layer, a third Si layer, a third SiO2 layer, a fourth Si layer, a fourth SiO2 layer, a fifth Si layer, and a fifth SiO2 layer, arranged sequentially from the inside to the outside of the surface of the optical glass substrate.
[0023] In this embodiment, the thickness of the first Si layer is 10.12 nm; the thickness of the first SiO2 layer is 22.83 nm; the thickness of the second Si layer is 227.65 nm; the thickness of the second SiO2 layer is 206.47 nm; the thickness of the third Si layer is 15.71 nm; the thickness of the third SiO2 layer is 14.38 nm; the thickness of the fourth Si layer is 201.95 nm; the thickness of the fourth SiO2 layer is 16.07 nm; the thickness of the fifth Si layer is 8.92 nm; and the thickness of the fifth SiO2 layer is 85.15 nm.
[0024] The optical glass substrate described in this embodiment is a tempered optical glass substrate. Specifically, it is tempered K9 glass.
[0025] like Figure 1 As shown, the black glass sheet for laser radar described in this invention has a very low reflectivity for laser wavelengths of 1550nm, with an average reflectivity of 2% for incident light at 0-60 degrees, thus ensuring efficient laser transmission; for visible light wavelengths of 400-700nm, the reflectivity is relatively consistent within the band, with an average reflectivity of 5.7% for incident light at 0 degrees, thus ensuring the blackness of the lens. Example 2
[0026] Unlike Example 1, the thickness of the first Si layer is 10.32 nm; the thickness of the first SiO2 layer is 23.28 nm; the thickness of the second Si layer is 232.21 nm; the thickness of the second SiO2 layer is 210.60 nm; the thickness of the third Si layer is 16.02 nm; the thickness of the third SiO2 layer is 14.67 nm; the thickness of the fourth Si layer is 205.99 nm; the thickness of the fourth SiO2 layer is 16.39 nm; the thickness of the fifth Si layer is 9.10 nm; and the thickness of the fifth SiO2 layer is 86.85 nm.
[0027] like Figure 2 As shown, the black glass sheet for laser radar described in this invention has a very low reflectivity for laser wavelengths of 1550nm, with an average reflectivity of 2% for incident light at 0-60 degrees, thus ensuring efficient laser transmission; for visible light wavelengths of 400-700nm, the reflectivity is relatively consistent within the band, with an average reflectivity of 5.7% for incident light at 0 degrees, thus ensuring the blackness of the lens. Example 3
[0028] Unlike Example 1, the thickness of the first Si layer is 9.92 nm; the thickness of the first SiO2 layer is 22.37 nm; the thickness of the second Si layer is 223.10 nm; the thickness of the second SiO2 layer is 202.34 nm; the thickness of the third Si layer is 15.40 nm; the thickness of the third SiO2 layer is 14.09 nm; the thickness of the fourth Si layer is 197.91 nm; the thickness of the fourth SiO2 layer is 15.75 nm; the thickness of the fifth Si layer is 8.74 nm; and the thickness of the fifth SiO2 layer is 83.45 nm.
[0029] like Figure 3 As shown, the black glass sheet for laser radar described in this invention has a very low reflectivity for laser wavelengths of 1550nm, with an average reflectivity of 2% for incident light at 0-60 degrees, thus ensuring efficient laser transmission; for visible light wavelengths of 400-700nm, the reflectivity is relatively consistent within the band, with an average reflectivity of 5.7% for incident light at 0 degrees, thus ensuring the blackness of the lens.
[0030] This invention is not limited to the above embodiments. Any simple substitutions made based on the principles of this invention are within the scope of protection of this invention.
Claims
1. A black lens for lidar, characterized in that: It includes an optical glass substrate and a film layer deposited on both sides of the optical glass substrate. The film layer consists of a first Si layer, a first SiO2 layer, a second Si layer, a second SiO2 layer, a third Si layer, a third SiO2 layer, a fourth Si layer, a fourth SiO2 layer, a fifth Si layer, and a fifth SiO2 layer, arranged sequentially from the inside to the outside of the surface of the optical glass substrate. The thickness of the first Si layer is 9.92-10.32 nm; the thickness of the first SiO2 layer is 22.37-23.28 nm; the thickness of the second Si layer is 223.10-232.21 nm; the thickness of the second SiO2 layer is 202.34-210.60 nm; the thickness of the third Si layer is 15.40-16.02 nm; the thickness of the third SiO2 layer is 14.09-14.67 nm; the thickness of the fourth Si layer is 197.91-205.99 nm; the thickness of the fourth SiO2 layer is 15.75-16.39 nm; the thickness of the fifth Si layer is 8.74-9.10 nm; and the thickness of the fifth SiO2 layer is 83.45-86.85 nm.
2. The black lens for laser radar according to claim 1, characterized in that: The thickness of the first Si layer is 10.12 nm; the thickness of the first SiO2 layer is 22.83 nm; the thickness of the second Si layer is 227.65 nm; the thickness of the second SiO2 layer is 206.47 nm; the thickness of the third Si layer is 15.71 nm; the thickness of the third SiO2 layer is 14.38 nm; the thickness of the fourth Si layer is 201.95 nm; the thickness of the fourth SiO2 layer is 16.07 nm; the thickness of the fifth Si layer is 8.92 nm; and the thickness of the fifth SiO2 layer is 85.15 nm.
3. The black lens for laser radar according to claim 1, characterized in that: The thickness of the first Si layer is 10.32 nm; the thickness of the first SiO2 layer is 23.28 nm; the thickness of the second Si layer is 232.21 nm; the thickness of the second SiO2 layer is 210.60 nm; the thickness of the third Si layer is 16.02 nm; the thickness of the third SiO2 layer is 14.67 nm; the thickness of the fourth Si layer is 205.99 nm; the thickness of the fourth SiO2 layer is 16.39 nm; the thickness of the fifth Si layer is 9.10 nm; and the thickness of the fifth SiO2 layer is 86.85 nm.
4. The black lens for laser radar according to claim 1, characterized in that: The thickness of the first Si layer is 9.92 nm; the thickness of the first SiO2 layer is 22.37 nm; the thickness of the second Si layer is 223.10 nm; the thickness of the second SiO2 layer is 202.34 nm; the thickness of the third Si layer is 15.40 nm; the thickness of the third SiO2 layer is 14.09 nm; the thickness of the fourth Si layer is 197.91 nm; the thickness of the fourth SiO2 layer is 15.75 nm; the thickness of the fifth Si layer is 8.74 nm; and the thickness of the fifth SiO2 layer is 83.45 nm.
5. A black lens for laser radar according to any one of claims 1-4, characterized in that: The optical glass substrate is a tempered optical glass substrate.