Super-clear large target surface thermal drift stable auxiliary driving optical system

Abstract

The present application relates to the field of optical imaging technology, especially to a kind of super-clear large target surface thermal drift stabilizing auxiliary driving optical system, the optical system includes first lens, second lens, third cemented lens group, fifth lens, sixth cemented lens group, eighth lens and optical filter in order from object side to image side along optical axis direction;First lens is meniscus lens with negative optical power;Second lens is concave-convex lens with negative optical power;The optical power of third cemented lens group is positive;Fifth lens is biconvex lens with positive optical power;The optical power of sixth cemented lens group is positive;Eighth lens is concave-convex lens with negative optical power.This kind of super-clear large target surface thermal drift stabilizing auxiliary driving optical system gives consideration to super-clear large target surface, large aperture, purple edge optimization and ensure resolving power requirement under high-low temperature environment.

Description

Technical Field

[0001] This invention relates to the field of optical imaging technology, specifically to an ultra-high-definition large-target thermal drift stabilization assisted driving optical system. Background Technology

[0002] Nowadays, automotive driver assistance systems (ADAS) are receiving increasing attention, and in-vehicle ADAS are constantly evolving. These systems utilize sensors such as cameras and radar installed in vehicles to perceive the surrounding environment and collect data. After identifying, detecting, and tracking static and dynamic objects, the system's calculations and analysis allow drivers and passengers to anticipate potential situations and dangers, effectively avoiding safety hazards caused by blind spots and reducing the likelihood of traffic accidents. The market demand for in-vehicle ADAS is growing, and the technical requirements for ADAS optical systems are also increasing. However, existing technologies generally suffer from problems such as a target area smaller than 7mm, low overall image brightness, insufficient image quality, purple fringing at the edges of photographed objects, and poor imaging performance in high or low temperature environments. For example, Chinese patent application number 201611209922.9 discloses a large-aperture high-definition optical system and its application lens; however, actual testing and research have revealed the following shortcomings of this existing technology:

[0003] 1. The lens has a relative aperture of 1.7 and a relatively small aperture, resulting in low brightness of the video image in darker environments.

[0004] 2. It is compatible with 1 / 3" sensors, but the target area is small and cannot be matched with large-target high-definition chips.

[0005] 3. As can be seen from the basic parameter table of the optical system in the existing technical solution, all six lenses are made of glass. This all-glass structure does not use high and low temperature resistant lens materials, and its thermal drift is unstable in high and low temperature environments. Summary of the Invention

[0006] To address the problems existing in the prior art, the purpose of this invention is to provide an ultra-high-definition large-aperture thermal drift stabilization assisted driving optical system. This ultra-high-definition large-aperture thermal drift stabilization assisted driving optical system takes into account the requirements of ultra-high-definition large aperture, large aperture, purple fringing optimization, and resolution under high and low temperature environments.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution: an ultra-high-definition large target surface thermal drift stabilization assisted driving optical system, which includes, in sequence from the object side to the image side along the optical axis, a first lens, a second lens, a third cemented lens group, a fifth lens, a sixth cemented lens group, an eighth lens, and a filter;

[0008] The first lens is a meniscus lens with negative optical power;

[0009] The second lens is a concave-convex lens with negative optical power;

[0010] The optical power of the third cemented lens group is positive;

[0011] The fifth lens is a biconvex lens with positive optical power;

[0012] The optical power of the sixth cemented lens group is positive;

[0013] The eighth lens is a concave-convex lens with negative optical power.

[0014] In some embodiments, the third cemented lens group includes a third lens and a fourth lens, wherein the third lens is a biconvex lens with negative optical power and the fourth lens is a meniscus lens with positive optical power.

[0015] The sixth cemented lens group includes a sixth lens and a seventh lens, wherein the sixth lens is a biconvex lens with positive optical power, and the seventh lens is a meniscus lens with positive optical power.

[0016] In some embodiments, the object-side surface of the first lens is convex, and the image-side surface is concave.

[0017] The second lens has a stepped concave surface on the object side and a slightly convex surface on the image side.

[0018] The third lens has a slightly convex surface on the object side and a highly convex surface on the image side.

[0019] The fourth lens has a concave surface facing the object side and a convex surface facing the image side.

[0020] The fifth lens has a convex surface on the object side and a slightly convex surface on the image side.

[0021] The sixth lens has a small convex surface on the object side and a large convex surface on the image side.

[0022] The seventh lens has a concave surface facing the object side and a convex surface facing the image side.

[0023] The eighth lens has a slightly convex surface on the object side and a concave surface on the image side.

[0024] In some embodiments, the ratio of the focal length of the first to eighth lenses to the focal length of the lens satisfies the following set relationship:

[0025] 1.6<|f1 / f|<2.5, 1.2<|f2 / f|<2.1, 5.2<|f3 / f|<6.3, 2.4<|f4 / f|<3.1, 1.4 <|f5 / f|<2.3, 11.4<|f6 / f|<12.7, 97.7<|f7 / f|<99.1, 11.3<|f8 / f|<12.3;

[0026] Wherein, f1 represents the effective focal length of the first lens, f2 represents the effective focal length of the second lens, f3 represents the effective focal length of the third lens, f4 represents the effective focal length of the fourth lens, f5 represents the effective focal length of the fifth lens, f6 represents the effective focal length of the sixth lens, f7 represents the effective focal length of the seventh lens, f8 represents the effective focal length of the eighth lens, and f represents the effective focal length of the optical system.

[0027] In some embodiments, the refractive indices of the first to eighth lenses satisfy the following condition:

[0028] 1.2 <n1<1.9,1.5<n2<2.0,1.4<n3<2.0,1.3<n4<2.2,1.7<n5<2.4,1.3<n6<1.9,1.8<n7<2.2,1.4<n8<2.2;

[0029] Wherein, n1 is the refractive index of the first lens, n2 is the refractive index of the second lens, n3 is the refractive index of the third lens, n4 is the refractive index of the fourth lens, n5 is the refractive index of the fifth lens, n6 is the refractive index of the sixth lens, n7 is the refractive index of the seventh lens, and n8 is the refractive index of the eighth lens.

[0030] In some embodiments, the Abbe coefficients of both the fifth and seventh lenses are greater than 16 and less than 37.

[0031] In some embodiments, the Abbe coefficients of both the second lens and the eighth lens are greater than 51 and less than 59.

[0032] In some embodiments, the hologram height IH of the optical system satisfies the following condition: IH ≥ 9.6 mm.

[0033] In some embodiments, the effective focal length f of the optical system satisfies the following condition: 6.3mm ≤ f ≤ 6.7mm.

[0034] In summary, the present invention has the following beneficial effects:

[0035] This ultra-high-definition large-target thermal drift stabilization assisted driving optical system comprises, along the optical axis from the object side to the image side, the following components in sequence: a first meniscus lens with negative optical power, a second concave-convex lens with negative optical power, a third cemented lens group with positive optical power, a fifth biconvex lens with positive optical power, a sixth cemented lens group with positive optical power, an eighth concave-convex lens with negative optical power, a filter, and an image plane; wherein the surface of the first meniscus lens facing the object side is convex. An optical system employing lenses with specific structural shapes and reasonable power distribution achieves a full-image height of 9.6mm. Combined with a large aperture lens, it can be matched with a 1 / 1.9” large-area chip, supporting 12M high-definition video recording and meeting high demands for imaging quality. Furthermore, the high aperture of f / 1.6 allows for greater light absorption, effectively improving nighttime visibility. In addition, the structural shape of the optical lens system provided by this invention, along with the Abbe coefficient and other parameters of the optical glass material, are well-matched to imaging conditions. The two sets of cemented glass lenses effectively reduce spherical aberration, coma, astigmatism, field curvature, and position distortion of the entire lens system. The design incorporates chromatic aberration and magnification chromatic aberration correction, improving the final image quality and chromatic aberration correction. The use of low-dispersion materials optimizes the purple fringing effect at object edges, better reproducing the true scene. Simultaneously, the entire optical system has thermal compensation, maintaining thermal drift stability at high temperatures of 85℃ and low temperatures of -40℃, ensuring resolution requirements at both high and low temperatures. If a spherical glass system were used, the total number of lenses in the optical system would reach 9-10 or more. The optical system provided by this invention uses a structure of 7 spherical glass elements and 1 molded glass element, reducing the number of lenses in the original design, miniaturizing the lens, and lowering costs. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of a lens according to an embodiment of the present invention;

[0037] Figure 2 This is a defocusing curve at 20°C with a speed of 100 lp / mm, according to an embodiment of the present invention.

[0038] Figure 3 This is a defocusing curve at 85°C and 100 lp / mm, according to an embodiment of the present invention.

[0039] Figure 4 This is a defocusing curve at -40℃ with 100 lp / mm according to an embodiment of the present invention;

[0040] Figure 5 This is an analytical plot of 100 lp / mm MTF at 20°C according to an embodiment of the present invention;

[0041] Figure 6 This is an analytical plot of 100 lp / mm MTF at 85°C according to an embodiment of the present invention;

[0042] Figure 7This is an analytical plot of 100 lp / mm MTF at -40℃ according to an embodiment of the present invention;

[0043] Figure 8 This is a field curvature diagram of an embodiment of the present invention;

[0044] Figure 9 This is an optical distortion diagram according to an embodiment of the present invention.

[0045] In the diagram: E1, first lens; E2, second lens; E3, third lens; E4, fourth lens; E5, fifth lens; E6, sixth lens; E7, seventh lens; E8, eighth lens. Detailed Implementation

[0046] The following will provide an embodiment of the optical system of the present invention. It should be noted that the data listed in the table below are preferred data of the present invention and are not intended to limit the present invention. Any person skilled in the art, after referring to the present invention, can make appropriate changes to the parameters or settings, and such changes should still fall within the scope of the present invention.

[0047] surf Radius Thickness Index ABB EFL-E OBJ infinity 50000 1 17.8833295 1.05 1.49 70.4 -13.525 2 4.70075187 4.6830604 3 -6.654112118 0.78 1.7 55.5 -9.912 4 -180 0.5 5 100 2.804888853 1.59 68.6 -38.611 6 -5.152428172 0.929685355 1.76 27.5 18.161 7 -8.853634417 0.1 8 13.38236974 2.5 1.91 35.3 12.113 9 -58.89583422 0.1 STO infinity 3.890819184 11 11.55956173 3.284472794 1.59 68.6 79.597 12 -7.709562468 0.784 1.92 18.9 645.332 13 -20.8981033 0.5 14 60 1.67 1.69 53.2 -76.854 15 27.98927958 0.72 16 infinity 0.7 1.52 64.2 17 infinity 5.317873414 IMA infinity 0

[0048] Table 1

[0049] Aspherical coefficients are shown in Table 2:

[0050] SURFACE:14 K＝-13.20464740311 E4＝-0.0002578225038157 E6＝-0.00006419742205989 E8＝0.00001527707154648 E10＝-0.000001328174057645 E12 = 6.394619279449E-08 E14 = -1.450843633402E-09 R1＝59.9999999999988 SURFACE:15 K＝-31.43664178615 E4＝0.0006807319058897 E6＝-0.00005895448469989 E8＝0.00000951728482608 E10 = -8.865856676527E-07 E12 = 4.98536557334E-08 E14 = -1.134895935094E-09 R2＝27.9892795760443

[0051] Table 2

[0052] The aspherical coefficients satisfy the following equation:

[0053]

[0054] Where Z is the aspherical sagitta, c is the paraxial curvature of the aspherical surface, y is the lens aperture, k is the conic coefficient, a4 is the 4th order aspherical coefficient, a6 is the 6th order aspherical coefficient, a8 is the 8th order aspherical coefficient, a10 is the 10th order aspherical coefficient, a12 is the 12th order aspherical coefficient, and a14 is the 14th order aspherical coefficient.

[0055] Specifically, the R-values ​​and thicknesses of each lens surface in this embodiment are shown in Table 1, and the aspherical parameters are shown in Table 2.

[0056] The optical system provided in Table 1 has an effective focal length of 6.55mm, an aperture of F / 1.6, and an image size of 9.6mm. In Table 1, mirror numbers 1 and 2 represent the two mirrors of the first lens along the direction of light incidence, mirror numbers 3 and 4 represent the two mirrors of the second lens along the direction of light incidence, mirror number 5 represents the object-side mirror of the third lens, mirror number 6 represents the cemented surface of the third and fourth lenses, mirror number 7 represents the image-side mirror of the fourth lens, mirror numbers 8 and 9 represent the two mirrors of the fifth lens along the direction of light incidence, mirror number 11 represents the object-side mirror of the sixth lens, mirror number 12 represents the cemented surface of the sixth and seventh lenses, mirror number 13 represents the image-side mirror of the seventh lens, and mirror numbers 14 and 15 represent the two mirrors of the eighth lens along the direction of light incidence.

[0057] like Figure 1 As shown, an ultra-high-definition large target surface thermal drift stabilization assisted driving optical system includes, along the optical axis from the object side to the image side, a first lens, a second lens, a third cemented lens group, a fifth lens, a sixth cemented lens group, an eighth lens, and a filter.

[0058] The first lens is a meniscus lens with negative optical power;

[0059] The second lens is a concave-convex lens with negative optical power;

[0060] The optical power of the third cemented lens group is positive;

[0061] The fifth lens is a biconvex lens with positive optical power;

[0062] The optical power of the sixth cemented lens group is positive;

[0063] The eighth lens is a concave-convex lens with negative optical power.

[0064] The third cemented lens group includes a third lens and a fourth lens, wherein the third lens is a biconvex lens with negative optical power and the fourth lens is a meniscus lens with positive optical power.

[0065] The sixth cemented lens group includes a sixth lens and a seventh lens, wherein the sixth lens is a biconvex lens with positive optical power, and the seventh lens is a meniscus lens with positive optical power.

[0066] The first lens has a convex surface facing the object side and a concave surface facing the image side;

[0067] The second lens has a stepped concave surface on the object side and a slightly convex surface on the image side.

[0068] The third lens has a slightly convex surface on the object side and a highly convex surface on the image side.

[0069] The fourth lens has a concave surface facing the object side and a convex surface facing the image side.

[0070] The fifth lens has a convex surface on the object side and a slightly convex surface on the image side.

[0071] The sixth lens has a small convex surface on the object side and a large convex surface on the image side.

[0072] The seventh lens has a concave surface facing the object side and a convex surface facing the image side.

[0073] The eighth lens has a slightly convex surface on the object side and a concave surface on the image side.

[0074] In this embodiment of the invention, the ratio of the focal length of the first to eighth lenses to the focal length of the lens satisfies the following set relationship:

[0075] 1.6<|f1 / f|<2.5, 1.2<|f2 / f|<2.1, 5.2<|f3 / f|<6.3, 2.4<|f4 / f|<3.1, 1.4 <|f5 / f|<2.3, 11.4<|f6 / f|<12.7, 97.7<|f7 / f|<99.1, 11.3<|f8 / f|<12.3;

[0076] Wherein, f1 represents the effective focal length of the first lens, f2 represents the effective focal length of the second lens, f3 represents the effective focal length of the third lens, f4 represents the effective focal length of the fourth lens, f5 represents the effective focal length of the fifth lens, f6 represents the effective focal length of the sixth lens, f7 represents the effective focal length of the seventh lens, f8 represents the effective focal length of the eighth lens, and f represents the effective focal length of the optical system.

[0077] The refractive indices of the first to eighth lenses in this embodiment of the invention satisfy the following conditions:

[0078] 1.2 <n1<1.9,1.5<n2<2.0,1.4<n3<2.0,1.3<n4<2.2,1.7<n5<2.4,1.3<n6<1.9,1.8<n7<2.2,1.4<n8<2.2;

[0079] Wherein, n1 is the refractive index of the first lens, n2 is the refractive index of the second lens, n3 is the refractive index of the third lens, n4 is the refractive index of the fourth lens, n5 is the refractive index of the fifth lens, n6 is the refractive index of the sixth lens, n7 is the refractive index of the seventh lens, and n8 is the refractive index of the eighth lens.

[0080] In this embodiment of the invention, the Abbe coefficients of the fifth and seventh lenses are both greater than 16 and less than 37, and the Abbe coefficients of the second and eighth lenses are both greater than 51 and less than 59.

[0081] The hologram height IH of the optical system described in this embodiment of the invention satisfies the following condition: IH ≥ 9.6 mm.

[0082] The effective focal length f of the optical system described in this embodiment of the invention satisfies the following condition: 6.3mm ≤ f ≤ 6.7mm.

[0083] All of the above embodiments of the present invention meet the requirements.

[0084] In an embodiment of the present invention, Figure 5 This is a modulation transfer function (MTF) curve for the visible light band, representing the overall resolving power of an optical system. The horizontal axis represents spatial frequency, in cycles per millimeter (mm), and the vertical axis represents the MTF value. The MTF value is used to evaluate the image quality of a lens, ranging from 0 to 1. It is worth noting that the optical transfer function is a relatively accurate, intuitive, and common way to evaluate the image quality of an optical system. The higher and smoother the curve, the better the image quality and the stronger the ability to reproduce the true image. Figure 5 It can be seen that in the visible light band, at a spatial frequency of 100 lp / mm, the MTF in the imaging region near the center is >0.7, indicating good imaging quality. Figure 2 The defocus curve shows that the lens has good MTF concentration, facilitating focusing. The optical system provided in this specific implementation corrects for various aberrations, such as spherical aberration, coma, astigmatism, field curvature, magnification chromatic aberration, and positional chromatic aberration, thereby improving the final image quality; from Figures 2 to 7 It can be seen that the defocus curve and MTF at both high and low temperatures meet the requirements of high resolution, the focus change of the defocus curve is small, and the thermal drift effect is stable.

[0085] Through the above technical solutions, the optical system provided by this invention, by employing an optical system composed of lenses with specific structural shapes and reasonable optical power distribution, achieves a full-image height of 9.6mm. Combined with a large aperture lens, it can be matched with a 1 / 1.9” large-area chip, supporting 12M high-definition video recording, meeting high demands for imaging quality. Furthermore, the high aperture of f / 1.6 allows for the absorption of more light, effectively improving nighttime visibility. In addition, the structural shape of the optical lens system provided by this invention, along with parameters such as the Abbe coefficient of the optical glass material, is well-matched to imaging conditions. The two sets of cemented glass lenses effectively reduce the spherical shape of the entire lens system. The system addresses aberrations such as coma, astigmatism, field curvature, positional chromatic aberration, and magnification chromatic aberration, improving the final image quality and chromatic aberration correction. The design utilizes low-dispersion materials, optimizing the purple fringing effect at object edges for better reproduction of realistic scenes. Simultaneously, the entire optical system exhibits thermal compensation, maintaining thermal drift stability at high temperatures (85℃) and low temperatures (-40℃), ensuring resolution requirements at both high and low temperatures. If a spherical glass system were used, the total number of lenses in the optical system would reach 9-10 or more. The optical system provided by this invention employs a structure of 7 spherical glass elements and 1 molded glass element, reducing the number of lenses in the original design, miniaturizing the lens, and lowering costs.

[0086] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A high-definition, large-target-area thermal drift stabilization assisted driving optical system, characterized in that: The first lens, the second lens, the third cemented lens group, the fifth lens, the sixth cemented lens group, the eighth lens and the filter are sequentially arranged along the optical axis from the object side to the image side; The first lens is a meniscus lens with negative refractive power; The second lens is a biconcave lens with negative refractive power; The third cemented lens group has positive refractive power; The fifth lens is a biconvex lens with positive refractive power; The sixth cemented lens group has positive refractive power; The eighth lens is a biconcave lens with negative refractive power; The third cemented lens group comprises a third lens and a fourth lens, wherein the third lens is a biconvex lens with negative refractive power, and the fourth lens is a meniscus lens with positive refractive power; The sixth cemented lens group comprises a sixth lens and a seventh lens, wherein the sixth lens is a biconvex lens with positive refractive power, and the seventh lens is a meniscus lens with positive refractive power; The first lens has a convex surface on the object side and a concave surface on the image side; The second lens has a stepped concave surface on the object side and a convex surface on the image side; The third lens has a convex surface on the object side and a convex surface on the image side; The fourth lens has a concave surface on the object side and a convex surface on the image side; The fifth lens has a convex surface on the object side and a convex surface on the image side; The sixth lens has a convex surface on the object side and a convex surface on the image side; The seventh lens has a concave surface on the object side and a convex surface on the image side; The eighth lens has a convex surface on the object side and a concave surface on the image side.

2. The ultra-clear large target surface thermal drift stabilized auxiliary driving optical system according to claim 1, characterized in that: The ratio of the focal length of the first lens to the eighth lens to the focal length of the lens satisfies the following set relationship: 1.6<|f1 / f|<2.5, 1.2<|f2 / f|<2.1, 5.2<|f3 / f|<6.3, 2.4<|f4 / f|<3.1, 1.4<|f5 / f|<2.3, 11.4<|f6 / f|<12.7, 97.7<|f7 / f|<99.1, 11.3<|f8 / f|<12.3; wherein f1 represents the effective focal length of the first lens, f2 represents the effective focal length of the second lens, f3 represents the effective focal length of the third lens, f4 represents the effective focal length of the fourth lens, f5 represents the effective focal length of the fifth lens, f6 represents the effective focal length of the sixth lens, f7 represents the effective focal length of the seventh lens, f8 represents the effective focal length of the eighth lens, and f represents the effective focal length of the optical system.

3. The ultra-clear large target surface thermal drift stabilized auxiliary driving optical system according to claim 1, characterized in that: The refractive index of the first lens to the eighth lens satisfies the following conditions: 1.2<n1<1.9, 1.5<n2<2.0, 1.4<n3<2.0, 1.3<n4<2.2, 1.7<n5<2.4, 1.3<n6<1.9, 1.8<n7<2.2, 1.4<n8<2.2; Wherein, n1 is the refractive index of the first lens, n2 is the refractive index of the second lens, n3 is the refractive index of the third lens, n4 is the refractive index of the fourth lens, n5 is the refractive index of the fifth lens, n6 is the refractive index of the sixth lens, n7 is the refractive index of the seventh lens, and n8 is the refractive index of the eighth lens.

4. The ultra-clear large target surface thermal drift stabilized auxiliary driving optical system according to claim 1, characterized in that: The Abbe number of the fifth lens and the seventh lens is greater than 16 and less than 37.

5. The ultra-clear large target surface thermal drift stabilized auxiliary driving optical system according to claim 1, characterized in that: The Abbe number of the second lens and the eighth lens is greater than 51 and less than 59.

6. A super-clear large target surface thermal drift stabilized auxiliary driving optical system according to any one of claims 1-5, characterized in that: The total image height IH of the optical system satisfies the condition: IH≥9.6mm.

7. A super-clear large target surface thermal drift stabilized auxiliary driving optical system according to any one of claims 1-5, characterized in that: The effective focal length f of the optical system satisfies the condition: 6.3mm≤f≤6.7mm.

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