DMS superlens imaging lens and system

Abstract

The invention relates to a DMS superlens imaging lens and system, and belongs to the field of optical lenses, the imaging lens is sequentially provided with a diaphragm and a first lens from an object plane to an image plane along an optical axis, and the object side surface and / or the image side surface of the first lens are / is a metasurface. According to the imaging lens, large-target-surface visible light imaging is achieved only through one super lens, the complexity of a system is reduced, the size and weight are reduced, and cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of optical lenses, and specifically relates to a DMS superlens imaging lens and system. Background Technology

[0002] With the rapid development of intelligent driving technology, driver monitoring systems (DMS) are playing an increasingly important role in improving driving safety and user experience. By monitoring the driver's facial expressions, gaze direction, fatigue level, and other information in real time, DMS systems can effectively prevent traffic accidents caused by driver inattention or fatigue.

[0003] However, the optical imaging technology relied upon by traditional DMS systems has many limitations, and a more efficient and compact solution is urgently needed. Summary of the Invention

[0004] This application provides a DMS superlens imaging lens and system to at least solve the above-mentioned technical problems existing in the prior art.

[0005] One embodiment of this application provides a DMS superlens imaging lens, wherein an aperture and a first lens are arranged sequentially along the optical axis from the object plane to the image plane, and the object side and / or image side of the first lens are metasurfaces. The imaging lens satisfies: in, This refers to the maximum image height of a DMS superlens imaging lens. This refers to the aperture number. The diagonal field of view is TTL, and the distance from the center of the optical axis on the object side of the first lens to the image plane is TTL.

[0006] In one possible implementation, the imaging lens further satisfies: .

[0007] In one embodiment, the first lens is a lens with positive optical power, wherein the object side is a plane and the image side is a plane.

[0008] In one embodiment, the metasurface is composed of periodically arranged microstructures, and the arrangement of microstructures on the metasurface can effectively control light to achieve imaging function.

[0009] In one embodiment, the microstructure is one or more of the following: cylinder, ring, square, and cross.

[0010] In one embodiment, the thickness of the metasurface is between 0.2 mm and 1 mm.

[0011] In one embodiment, the focal length f of the imaging lens satisfies f≥3.5mm.

[0012] In one possible implementation, the field of view of the imaging lens FOV satisfy .

[0013] In one embodiment, the operating temperature of the imaging lens is -30℃ to 70℃.

[0014] Another aspect of this application provides a DMS superlens imaging system, including any of the aforementioned DMS superlens imaging lenses.

[0015] Compared with the prior art, this application has the following advantages: The DMS superlens imaging lens of this application achieves visible light imaging of a large target surface using only one superlens, reducing the complexity of the system, reducing size and weight, and reducing cost. The DMS superlens imaging lens of the present invention has a large aperture and a large field of view, which can meet the application of vehicle-mounted DMS and achieve high-resolution imaging. The DMS superlens imaging lens of the present invention adopts a single superlens design, which is temperature insensitive and can be used in different temperature scenarios. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the DMS superlens imaging lens in Embodiment 1 of this application; Figure 2 This is a schematic diagram of the MTF of the DMS superlens imaging lens in Embodiment 1 of this application; Figure 3 This is a schematic diagram of the blur spot of the DMS superlens imaging lens in Embodiment 1 of this application; Figure 4 This is a schematic diagram of the relative illumination of the DMS superlens imaging lens in Embodiment 1 of this application; Figure 5 This is a schematic diagram of the structure of the DMS superlens imaging lens in Embodiment 2 of this application; Figure 6 This is a schematic diagram of the MTF of the DMS superlens imaging lens in Embodiment 2 of this application; Figure 7 This is a schematic diagram of the blur spot of the DMS superlens imaging lens in Embodiment 2 of this application; Figure 8 This is a schematic diagram of the relative illumination of the DMS superlens imaging lens in Embodiment 2 of this application; Explanation of reference numerals in the attached figures: 100. Aperture stop; 110. First lens; 111. Metasurface; 120. Image plane. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings.

[0018] In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0019] Traditional optical imaging systems have the following limitations: 1. Size and weight: Traditional DMS systems typically use multi-lens groups, resulting in a large and heavy optical system that is difficult to meet the requirements of modern automobiles for lightweight and compact design.

[0020] 2. Manufacturing and assembly complexity: The manufacturing, assembly and alignment of multiple lenses require high-precision processes, which increases production costs and manufacturing difficulty.

[0021] 3. Field of view and imaging quality: Traditional optical systems have a trade-off between field of view and imaging depth, making it difficult to simultaneously meet the requirements of a large field of view and high imaging quality.

[0022] 4. Cost and scalability: The complex structure and high precision requirements of traditional optical systems result in high costs and make it difficult to quickly adapt to the needs of different application scenarios.

[0023] Metalens are a novel type of optical element based on metamaterials, achieving precise control of light waves through nanoscale structural design. Compared to traditional lenses, metalens have the following significant advantages: 1. Miniaturization and weight reduction: The thickness of the superlens is only on the micrometer scale, which can significantly reduce the size and weight of the optical system.

[0024] 2. High-precision control: By designing nanostructures, superlenses can achieve precise control over the phase, amplitude, and polarization of light waves, thereby improving imaging quality.

[0025] 3. Low-cost manufacturing: Superlenses can be manufactured on a large scale using semiconductor technology, which significantly reduces production costs.

[0026] 4. Multifunctional integration: Superlenses can simultaneously achieve multiple optical functions (such as focusing, dispersion correction, etc.), simplifying optical system design.

[0027] This application discloses a DMS (Digital Microlens) imaging lens, comprising an aperture and a first lens arranged sequentially along the optical axis from the object plane to the image plane. The object-side and / or image-side of the first lens is a metasurface. The metasurface is composed of periodically arranged microstructures, which can effectively control light to achieve imaging. Its thickness is between 0.2 mm and 1 mm, its diameter is between 100 and 350 nm, and its period is between 350 and 500 nm. In this embodiment, the optimal thickness is 700 nm and the optimal period is 450 nm. The microstructure material is silicon dioxide, including cylindrical, annular, square, and cross-shaped shapes, and may be composed of one or more of these shapes.

[0028] The imaging lens satisfies: in, Here, is the maximum image height of a DMS superlens imaging lens, and is the aperture number. The diagonal field of view is TTL, and the distance from the center of the optical axis on the object side of the first lens to the image plane is TTL.

[0029] In the embodiments of this application, the focal length f of the imaging lens satisfies f ≥ 3.5mm; the field of view... FOV satisfy The operating temperature range is -30℃ to 70℃.

[0030] In some embodiments, the first lens is a lens with positive optical power, wherein the object side is a plane and the image side is a plane.

[0031] The following two examples illustrate this in detail. Example

[0032] Table 1 shows the parameters of a DMS superlens imaging lens provided in this embodiment.

[0033] Table 1

[0034] Figure 1 This is a schematic diagram of the structure of a DMS superlens imaging lens under normal temperature conditions, provided by an embodiment of the present invention. Figure 1 As shown, an embodiment of the present invention provides a DMS superlens imaging lens comprising an aperture stop 100, a first lens 110, and an image plane 120 arranged sequentially along the optical axis from the object plane to the image plane. A visible light lens is also provided to satisfy the following: The DMS superlens imaging lens has a large focal length in the central region (focal length can reach 3.5mm or more); and the overall field of view of the lens is also large (field of view can reach 70° or more); among them, This represents the maximum image height of the DMS superlens imaging lens. This refers to the aperture number. Focal length This is the diagonal field of view.

[0035] As one possible implementation, at least one of the object side and the image side of the first lens 110 is a metasurface.

[0036] In this embodiment, the image side of the first lens 110 is set as a metasurface, its object side is a plane, and the image side has a microstructure arrangement.

[0037] As one possible implementation, the first lens 110 is made of glass.

[0038] By strategically arranging micro- and nano-structures on the metasurface of the first lens 110, the DMS superlens imaging lens achieves achromatic imaging capabilities, ensuring consistent image quality within a certain range. Furthermore, the material exhibits low temperature sensitivity, enabling a thermal design that reduces material costs and system size.

[0039] like Figure 1 As shown, the incident light enters the object side of the first lens 110 through the aperture 100, and then passes through the metasurface 111 on the image side of the first lens 110, where the light is modulated and focused onto the image plane 120.

[0040] For example, Table 1 details the specific optical data parameters of each lens in a DMS superlens imaging lens provided in an embodiment of the present invention, according to a feasible implementation. The optical data parameters in Table 1 correspond to... Figure 1 The image shown is a DMS superlens imaging lens.

[0041] Table 2 shows the parameters of each surface in the optical system provided in Example 1. The first lens is a lens with positive optical power, its object side is a plane, its image side is a plane and has microstructures arranged on it.

[0042] Table 2

[0043] The surface numbers are assigned according to the order of the lenses' surfaces. For example, surface number 3 represents the object-side surface of the first lens 110, surface number 4 represents the image-side surface of the first lens 110, and so on. The radius of curvature represents the degree of curvature of the lens surface; a positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "Infinity" is also a variable term. The value indicates that the surface is planar; the spacing represents the central axial distance from the current surface to the next surface. The units for both the radius of curvature and the spacing are millimeters (mm). The values ​​in the material represent the refractive index and Abbe number of the material used.

[0044] For example, Table 3 details the phase of the metasurface in this embodiment with a feasible implementation method.

[0045] Table 3

[0046] Figure 2 This is a schematic diagram of the MTF of a DMS superlens imaging lens provided in Embodiment 1 of the present invention. The lens provided in Embodiment 1 of the present invention has a value of >0.4 at 60 lp / mm, which can meet the requirements of high-resolution imaging.

[0047] Figure 3 This is a schematic diagram of the MTF of a DMS superlens imaging lens provided in Embodiment 1 of the present invention. The lens provided in Embodiment 1 of the present invention has a relatively concentrated and uniformly distributed diffusion pattern across the entire long wavelength band, which can meet the requirements of high-resolution imaging.

[0048] Figure 4 This is a schematic diagram of the relative illumination of a DMS superlens imaging lens provided in Embodiment 1 of the present invention, which represents the relative illumination values ​​corresponding to different fields of view, such as... Figure 4 As shown, the DMS superlens imaging lens provided in Embodiment 1 of the present invention has a relative illumination greater than 95% in the working band. Example

[0049] Table 4 shows the parameters of a DMS superlens imaging lens provided in this embodiment.

[0050] Table 4

[0051] Table 5 shows the parameters of each surface in the optical system provided in Example 2. The values ​​in the material table represent the refractive index and Abbe number of the material used.

[0052] Table 5

[0053] For example, Table 6 details the phase of the metasurface in this embodiment with a feasible implementation.

[0054] Table 6

[0055] Where R1 is the normalized radius of the binary surface.

[0056] For the analysis of each surface in Tables 5-6, please refer to Example 1. This example will not analyze them further.

[0057] Figure 5 This is a schematic diagram of the structure of a DMS superlens imaging system provided in Embodiment 1 of the present invention. From the object plane side to the image plane side, these are the aperture stop, the first lens, and the image plane.

[0058] Figure 6 This is a schematic diagram of the MTF of a DMS superlens imaging system provided in Embodiment 2 of the present invention. The lens provided in Embodiment 2 of the present invention has a value of >0.5 at 60 lp / mm, which can meet the requirements of high-resolution imaging.

[0059] Figure 7 This is a schematic diagram of the MTF of a DMS superlens imaging system provided in Embodiment 2 of the present invention. The lens provided in Embodiment 2 of the present invention has a relatively concentrated and uniformly distributed diffusion pattern across the entire long wavelength band, which can meet the requirements of high-resolution imaging.

[0060] Figure 8 This is a schematic diagram of the relative illumination of a visible light projection lens provided in Embodiment 2 of the present invention, which represents the relative illumination values ​​corresponding to different fields of view, such as... Figure 4 As shown, the visible light projection lens provided in Embodiment 1 of the present invention has a relative illuminance greater than 95% in the working wavelength band.

[0061] In summary, the visible light projection lens provided by the embodiments of the present invention has a relatively large aperture, clear imaging, and low TTL, which can meet the requirements of high-resolution imaging and lightweight integration.

[0062] This application also discloses a DMS superlens imaging system, including any of the aforementioned DMS superlens imaging lenses.

[0063] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure 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 disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A vehicle-mounted DMS (Digital Superconducting Mechanism) hybrid lens, characterized in that, include: A first lens, a second lens, and a third lens are arranged sequentially from the object plane to the image plane along the optical axis; The first lens is a metasurface lens with positive optical power. The metasurface lens includes a substrate and a micro / nano structure disposed on the substrate. The object side and the image side of the first lens are both planar, and the image side has a micro / nano structure. The second lens is an aspherical lens with negative optical power, its object side is concave and its image side is convex. Both the object side and the image side of the second lens are aspherical. The third lens is an aspherical lens with positive optical power, its object side is convex and its image side is concave, and both the object side and image side of the third lens are aspherical.

2. The vehicle-mounted DMS hyperspectral hybrid lens according to claim 1, characterized in that, The vehicle-mounted DMS hybrid lens also includes a filter; the filter is located after the third lens.

3. The vehicle-mounted DMS folding-hybrid lens according to claim 1, characterized in that, The aforementioned vehicle-mounted DMS folding-hybrid lens satisfies: ； in, For the maximum image height of the vehicle-mounted DMS super-hybrid lens, This refers to the aperture number. Focal length This is the diagonal field of view.

4. The vehicle-mounted DMS hyperspectral hybrid lens according to claim 1, characterized in that, The aforementioned vehicle-mounted DMS folding-hybrid lens satisfies: ； in, TTL The distance from the center of the optical axis on the object side of the first lens to the image plane. 。 5. The vehicle-mounted DMS folding-hybrid lens according to claim 1, characterized in that, The substrate material of the first lens is glass, and the substrate thickness ranges from 0.2 to 0.7 mm; the micro / nano material of the first lens is silicon dioxide; the materials of the second and third lenses are plastic.

6. The vehicle-mounted DMS folding-hybrid lens according to claim 1, characterized in that, The vehicle-mounted DMS hybrid lens further includes an aperture stop; the aperture stop is located in front of the first lens, or the aperture stop is located in the optical path between the first lens and the second lens.

7. The vehicle-mounted DMS folding-hybrid lens according to claim 6, characterized in that, The aperture stop is located between the first lens and the second lens.

8. The vehicle-mounted DMS folding-hybrid lens according to claim 1, characterized in that, The field of view of the vehicle-mounted DMS hyper-hybrid lens FOV satisfy: .

9. The vehicle-mounted DMS folding-hybrid lens according to claim 1, characterized in that, The focal length of the vehicle-mounted DMS hyperfocal lens f satisfy: .

10. The vehicle-mounted DMS folding-hybrid lens according to claim 1, characterized in that, The operating temperature of the vehicle-mounted DMS superconducting lens is -30℃ to 70℃.

11. A vehicle-mounted DMS folding-supersonic hybrid camera module, characterized in that, Including the vehicle-mounted DMS super-hybrid lens as described in claims 1 to 8.

12. A vehicle-mounted DMS hybrid system, characterized in that, Including the vehicle-mounted DMS folding-super hybrid camera module as described in claim 9.

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