Optical lens
By designing specific optical power and surface shape for eight lenses, the imaging quality of the vehicle-mounted optical lens is optimized, solving the imaging problem under low-light conditions and achieving high imaging quality with ultra-wide angle, large image plane, and large aperture.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-24
- Publication Date
- 2026-03-10
AI Technical Summary
Existing automotive optical lenses perform poorly in low-light conditions, making it difficult to meet the high pixel and high resolution requirements of advanced driver assistance systems.
Employing an eight-lens structure, a combination of specific optical power and surface shape, including a combination of negative and positive optical power lenses, the imaging quality of the optical lens is optimized through reasonable optical power allocation and lens surface shape design.
It improves the imaging quality of the optical lens, achieving ultra-wide-angle, large image plane, and large aperture imaging effects, reducing aberrations, and enhancing imaging clarity and resolution under low-light conditions.
Smart Images
Figure CN120595451B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of imaging lenses, and particularly to an optical lens. BACKGROUND
[0002] With the increasing demand for driving experience, vehicle application optical lenses are increasingly used in intelligent driving, and the status of vehicle optical lenses in the automotive industry is continuously improving.
[0003] Advanced Driver Assistance System (ADAS) plays an important role in intelligent driving, which collects environmental information through various lenses combined with sensors to ensure the safety of drivers. In addition to the requirements of optical lenses for ADAS systems, such as light and thin shape, high pixel, high resolution, etc., the optical lenses are also required to clearly image under low illumination conditions, so it is necessary to develop an optical lens with good imaging effect. SUMMARY
[0004] To solve the above problems, the present application provides an optical lens with excellent imaging quality.
[0005] The technical scheme adopted by the present application is:
[0006] An optical lens, a total of eight lenses, including in order along the optical axis from the object side to the imaging surface:
[0007] The first lens with negative focal power, the object side surface is convex, and the image side surface is concave;
[0008] The second lens with negative focal power, the object side surface is concave, and the image side surface is concave;
[0009] The third lens with positive focal power;
[0010] The fourth lens with positive focal power, the object side surface is convex, and the image side surface is convex;
[0011] The fifth lens with positive focal power, the object side surface is convex, and the image side surface is convex;
[0012] The sixth lens with negative focal power, the object side surface is concave, and the image side surface is concave;
[0013] The seventh lens with positive focal power, the object side surface is convex;
[0014] The eighth lens with positive focal power, the object side surface is concave, and the image side surface is convex;
[0015] The object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: -0.7 < (R7+R8) / (R7-R8) < -0.3; the object side surface curvature radius R15 of the eighth lens and the image side surface curvature radius R16 of the eighth lens satisfy: 0.4 < (R15-R16) / (R15+R16) < 0.7.
[0016] Further preferably, the total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 7 < TTL / f < 8.5; the total track length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 3 < TTL / IH < 3.5.
[0017] Further preferably, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 80° < FOV / Fno < 100°; the real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.6 < IH / EPD < 4.5.
[0018] Further preferably, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.2 < IH / f < 2.6; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.89 < BFL / f < 0.92.
[0019] Further preferably, the object side surface aperture d1 of the first lens, the real image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.44 < d1 / (IH / 2) / tan(FOV / 2) < 0.57; the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -1.2 < f123 / f45678 < -0.6.
[0020] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.8 < f1 / f < -1.9; the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 3.2 < f3 / f < 10.
[0021] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -3.1 < f2 / f < -1.9; the object side surface curvature radius R3 of the second lens and the image side surface curvature radius R4 of the second lens satisfy: -0.7 < (R3+R4) / (R3-R4) < 0.2.
[0022] Further preferably, an effective focal length f of the optical lens and a focal length f4 of the fourth lens satisfy: 1.8 < f4 / f < 2.85; a radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 1.3 < R7 / f < 2.3; a radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -7.5 < R8 / f < -3.6.
[0023] Further preferably, an effective focal length f of the optical lens and a focal length f5 of the fifth lens satisfy: 1.3 < f5 / f < 2.2; a radius of curvature R9 of the object side surface of the fifth lens and a radius of curvature R10 of the image side surface of the fifth lens satisfy: -0.2 < (R9+R10) / (R9-R10) < 0.2.
[0024] Further preferably, an effective focal length f of the optical lens and a focal length f8 of the eighth lens satisfy: 13 < f8 / f < 19; a radius of curvature R15 of the object side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -55 < R15 / f < -26; a radius of curvature R16 of the image side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -11 < R16 / f < -8.
[0025] The optical lens provided by the present application adopts eight lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved, so that the lens has one or more advantages of super wide angle, large image surface, large aperture, high imaging quality, etc. BRIEF DESCRIPTION OF DRAWINGS
[0026] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:
[0027] Figure 1 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.
[0028] Figure 2 FIG. 2 is an F-Tan(Theta) distortion curve of the optical lens according to the embodiment 1 of the present application.
[0029] Figure 3 FIG. 3 is an MTF curve of the optical lens according to the embodiment 1 of the present application.
[0030] Figure 4 FIG. 4 is a structural schematic diagram of an optical lens according to another embodiment of the present application.
[0031] Figure 5F-Tan(Theta) Distortion curve of the optical lens in Embodiment 2 of the present application.
[0032] Figure 6 MTF curve chart of the optical lens in Embodiment 2 of the present application.
[0033] Figure 7 Structure diagram of the optical lens in Embodiment 3 of the present application.
[0034] Figure 8 F-Tan(Theta) Distortion curve of the optical lens in Embodiment 3 of the present application.
[0035] Figure 9 MTF curve chart of the optical lens in Embodiment 3 of the present application.
[0036] Figure 10 Structure diagram of the optical lens in Embodiment 4 of the present application.
[0037] Figure 11 F-Tan(Theta) Distortion curve of the optical lens in Embodiment 4 of the present application.
[0038] Figure 12 MTF curve chart of the optical lens in Embodiment 4 of the present application.
[0039] Figure 13 Structure diagram of the optical lens in Embodiment 5 of the present application.
[0040] Figure 14 F-Tan(Theta) Distortion curve of the optical lens in Embodiment 5 of the present application.
[0041] Figure 15 MTF curve chart of the optical lens in Embodiment 5 of the present application.
[0042] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION
[0043] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be understood that the detailed description is merely descriptive of embodiments of the present application and is not intended to limit the scope of the present application in any way. Throughout the description, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.
[0044] It should be noted that the terms first, second, third, etc. in the present description are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Thus, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.
[0045] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.
[0046] In the present description, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If the lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.
[0047] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, mean that something passively includes or holds, but do not exclude the presence of one or more additional features, elements, components, and / or combinations thereof. In addition, when such phrases as "at least one of" appear in a list of items, the phrase is intended to mean any one of the items individually, as well as a combination of any one or more of the items. Furthermore, when describing embodiments of the present application, the use of "may" indicates that one or more embodiments of the present application. Also, the word "exemplary" is intended to mean an example or an illustration.
[0048] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that the terms should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0049] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.
[0050] The optical lens provided in this embodiment of the invention has a total of eight lenses, which are arranged sequentially from the object side to the imaging plane along the optical axis as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens.
[0051] In some embodiments, the first lens may have negative optical power, with a convex object-side surface and a concave image-side surface. The second lens may have negative optical power, with both its object-side and image-side surfaces being concave. The third lens may have positive optical power, with both its object-side and image-side surfaces being either concave or convex. The fourth lens may have positive optical power, with both its object-side and image-side surfaces being convex. The fifth lens may have positive optical power, with both its object-side and image-side surfaces being convex. The sixth lens may have negative optical power, with both its object-side and image-side surfaces being concave. The seventh lens may have positive optical power, with both its object-side and image-side surfaces being convex or concave. The eighth lens may have positive optical power, with both its object-side and image-side surfaces being convex.
[0052] In some embodiments, the optical lens may also include an aperture stop, which may be located between the third and fourth lenses. It is understood that the aperture stop is used to limit the amount of light entering the lens to change the brightness of the image. When the aperture stop is located between the third and fourth lenses, it facilitates the correction of aperture aberrations.
[0053] In some embodiments, the optical lens may further include a filter and a protective glass, which are sequentially disposed along the optical axis between the eighth lens and the imaging plane. The filter is used to filter out interfering light, preventing it from reaching the imaging plane of the optical lens and affecting normal imaging. The protective glass protects the optical lens, preventing damage to the image sensor and affecting the lens's imaging performance.
[0054] In some embodiments, the fifth, sixth, and seventh lenses can be cemented together to form a cemented lens, which can effectively correct chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberrations of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.
[0055] In some embodiments, the object-side radius of curvature R7 of the fourth lens and the image-side radius of curvature R8 of the fourth lens satisfy: -0.7 < (R7 + R8) / (R7 - R8) < -0.3. Meeting this range helps to converge light while correcting field curvature and distortion of the optical lens, thus improving the image quality of the optical lens. More specifically, -0.65 < (R7 + R8) / (R7 - R8) < -0.36.
[0056] In some embodiments, the radius of curvature R15 of the object side surface of the eighth lens and the radius of curvature R16 of the image side surface of the eighth lens satisfy: 0.4 < (R15 - R16) / (R15 + R16) < 0.7. Meeting the above range is conducive to suppressing the angle of the marginal field of view incident on the imaging surface, effectively transmitting more light beams to the imaging surface, and at the same time being able to balance the field curvature and spherical aberration of the optical lens, improving the imaging quality of the optical lens. More specifically, 0.47 < (R15 - R16) / (R15 + R16) < 0.69.
[0057] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 7 < TTL / f < 8.5. Meeting the above range can effectively limit the length of the lens, which is conducive to the miniaturization of the optical lens. More specifically, 7.77 < TTL / f < 8.07.
[0058] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3 < TTL / IH < 3.5. Meeting the above range ensures that, with the same overall length of the lens, it has a larger image surface, can match a larger-sized imaging chip to achieve high-definition imaging, and can better achieve the balance between the small overall length and the large image surface of the lens. More specifically, 3.19 < TTL / IH < 3.33.
[0059] In some embodiments, the maximum field of view angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 80° < FOV / Fno < 100°. Meeting the above range limits that the optical lens has an appropriate field of view angle and f-number, can collect light at large angles and obtain good imaging quality. More specifically, 86.46° < FOV / Fno < 91.6°.
[0060] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.6 < IH / EPD < 4.5. Meeting the above range can increase the width of the light beam incident on the optical lens, improve the brightness of the optical lens at the image surface, and avoid the generation of vignetting. More specifically, 3.9 < IH / EPD < 4.13.
[0061] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.2 < IH / f < 2.6. Meeting the above range controls the image height and focal length of the optical lens within a reasonable range, helps the optical lens to have the characteristic of a large image surface, and improves the imaging quality. More specifically, 2.4 < IH / f < 2.45.
[0062] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.89 < BFL / f < 0.92. Meeting the above range defines that the optical lens has an appropriate back focus, facilitating the reasonable arrangement of the positions of each lens and reducing the processing and assembly difficulty at the same time.
[0063] In some embodiments, the clear aperture d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.44 < d1 / (IH / 2) / tan(FOV / 2) < 0.57. Meeting the above range can have a small front aperture while meeting the requirements of the optical lens having a large field angle and a large image plane.
[0064] In some embodiments, the combined focal length f123 of the first lens, the second lens, and the third lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy: -1.2 < f123 / f45678 < -0.6. Meeting the above range, by reasonably setting the relationship between the lens groups before and after the aperture stop, it is beneficial to balance various aberrations generated by the lens groups and improve the overall imaging quality. More specifically, -1.12 < f123 / f45678 < -0.68.
[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.8 < f1 / f < -1.9. Meeting the above range, by setting the first lens to have a negative refractive power, it is beneficial for the first lens to receive a larger angle of light and collect as much light as possible into the rear optical system, increasing the light flux while achieving a large field of view. More specifically, -2.61 < f1 / f < -2.13.
[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 3.2 < f3 / f < 10. Meeting the above range defines that the third lens has an appropriate positive optical power, which has the effect of converging light and depressing the peripheral light height, facilitating the reduction of the aperture of the rear lens. More specifically, 3.57 < f3 / f < 9.22.
[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -3.1 < f2 / f < -1.9; the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: -0.7 < (R3 + R4) / (R3 - R4) < 0.2; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -3.1 < R3 / f < -1.9; the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 1.7 < R4 / f < 9.6. Meeting the above ranges enables the second lens to have a negative optical power and a double concave surface shape, which has the effect of diverging light. At the same field angle, the light rays emerging from the image side surface of the first lens are further diverged, and the central rays and marginal rays of each field can be dispersed, allowing the rear optical system to have a larger light receiving surface to receive the light rays emerging from the image side surface of the second lens, achieving a larger light input, and being beneficial to increasing the relative illumination. More specifically, -2.91 < f2 / f < -2.07; -0.63 < (R3 + R4) / (R3 - R4) < 0.18; -2.85 < R3 / f < -2.07; 1.86 < R4 / f < 8.87.
[0068] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.8 < f4 / f < 2.85; the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 1.3 < R7 / f < 2.3; the curvature radius R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -7.5 < R8 / f < -3.6. Meeting the above ranges, the fourth lens has a positive optical power and a double convex surface shape, which can further focus the light, adjust the angle of the chief ray, optimize the imaging quality, and correct the remaining aberrations (such as distortion, chromatic aberration, etc.), reducing the distortion of the wide-angle lens. More specifically, 1.99 < f4 / f < 2.63; 1.49 < R7 / f < 2.09; -6.92 < R8 / f < -4.
[0069] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.3 < f5 / f < 2.2; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: -0.2 < (R9 + R10) / (R9 - R10) < 0.2; the radius of curvature R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 1.3 < R9 / f < 2.2; the radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -2.4 < R10 / f < -1.4. Satisfying the above ranges is conducive to the convergence of light, sharing the positive optical power of the third lens and the fourth lens, can avoid excessive light deflection, and better achieve high-quality imaging of the lens. More specifically, 1.39 < f5 / f < 1.98; -0.16 < (R9 + R10) / (R9 - R10) < 0.11; 1.48 < R9 / f < 1.97; -2.19 < R10 / f < -1.51.
[0070] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: 13 < f8 / f < 19; the radius of curvature R15 of the object side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -55 < R15 / f < -26; the radius of curvature R16 of the image side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -11 < R16 / f < -8. Satisfying the above ranges, setting the eighth lens to have positive refractive power and a suitable surface shape is conducive to light convergence, making the light trend smoothly transition to the rear, reducing the height of the light incident on the rear, slowing down the upward trend of the light, avoiding the light energy loss caused by the excessive main ray angle of the large field of view light reaching the imaging surface, being beneficial to improving the illuminance of the edge field of view, and being conducive to achieving a short optical total length. More specifically, 14.13 < f8 / f < 17.76; -53.05 < R15 / f < -29.07; -10.11 < R16 / f < -8.78.
[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1 < f6 / f < -0.7. Satisfying the above ranges makes the light in the edge field of view show an upward trend, which is conducive to the image point on the imaging surface being away from the optical axis, so as to be conducive to achieving the effect of matching with a large chip, obtaining a larger picture, effectively eliminating aberration, and improving the resolution ability of the optical lens. More specifically, -0.96 < f6 / f < -0.73.
[0072] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.2 < f7 / f < 2.3. Meeting the above range is beneficial to light convergence, enabling the light trend to smoothly transition to the rear, reducing the height of the light incident on the rear, slowing down the upward trend of the light, avoiding light energy loss caused by an excessive chief ray angle of the large field of view light when reaching the imaging surface, facilitating the improvement of the illuminance of the edge field of view, and being conducive to achieving a short overall optical length. More specifically, 1.36 < f7 / f < 2.09.
[0073] In some embodiments, the optical lens satisfies the following conditional expressions: 5 mm < f < 6 mm; 3 mm < EPD < 3.8 mm; 40 mm < TTL < 50 mm; 1.5 < Fno < 1.8; 16° < CRA < 22°; 5 mm < BFL < 5.2 mm; 140° < FOV < 160°; 13 mm < IH < 14 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the overall optical length of the optical lens, Fno represents the aperture value of the optical lens, CRA represents the chief ray incident angle of the optical lens, BFL represents the back focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, and IH represents the true image height corresponding to the maximum field of view angle of the optical lens. Meeting the above range, the optical lens has at least one or more advantages such as ultra-wide angle, large target surface, and large aperture. More specifically, 5.6 mm < f < 5.67 mm; 3.3 mm < EPD < 3.49 mm; 43.83 mm < TTL < 45.21 mm; 1.6 < Fno < 1.71; 16.68° < CRA < 21.46°; 5.07 mm < BFL < 5.09 mm; 143.9° < FOV < 150.3°; 13.6 mm < IH < 13.71 mm.
[0074] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. Additionally, when the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present invention can adopt an all-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.
[0075] In some embodiments, the first, second, third, fourth, fifth, sixth, seventh, and eighth lenses can be spherical or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce the aberrations of the optical system, thereby reducing the number of lenses and their size, and better achieving lens miniaturization. More specifically, the fourth and eighth lenses of this invention are aspherical lenses; the first, second, third, fifth, sixth, and seventh lenses are spherical lenses.
[0076] In various embodiments of the present invention, when an aspherical lens is used, the shapes of each aspherical surface of the optical lens satisfy the following equations:
[0077]
[0078] Where z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the quadratic surface coefficient, and B, C, D, E, and F are the fourth, sixth, eighth, tenth, and twelfth order surface coefficients, respectively.
[0079] The present invention will be further described below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different; for specific differences, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.
[0080] Example 1
[0081] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter G1, and a protective glass G2.
[0082] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.
[0083] The second lens L2 has negative optical power, its object side S3 is concave, and its image side S4 is concave.
[0084] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is convex.
[0085] The fourth lens L4 has positive optical power, its object side S7 is convex, and its image side S8 is convex.
[0086] The fifth lens L5 has positive optical power, its object side S9 is convex, and its image side is convex.
[0087] The sixth lens L6 has negative optical power, and its object side is concave, as is its image side.
[0088] The seventh lens L7 has positive optical power, its object side is convex, and its image side S12 is concave.
[0089] The fifth lens L5, the sixth lens L6 and the seventh lens L7 form a cemented lens group with positive optical power, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens is S10, and the cemented surface of the image side of the sixth lens L6 and the object side of the seventh lens L7 is S11.
[0090] The eighth lens L8 has positive optical power, its object side surface S13 is concave, and its image side surface S14 is convex.
[0091] The object-side surface S15 and the image-side surface S16 of filter G1 are both planar.
[0092] The object side S17 and image side S18 of the protective glass G2 are both flat.
[0093] The imaging plane S19 is a plane.
[0094] The fourth lens L4 and the eighth lens L8 are glass aspherical lenses; the first lens L1, the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are glass spherical lenses.
[0095] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1.
[0096] Table 1
[0097]
[0098] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.
[0099] Table 1-2
[0100] Face number K B C D E F S7 -1.86E+00 2.50E-04 9.65E-07 5.75E-08 -4.10E-09 1.23E-10 S8 1.14E+01 1.98E-04 -1.00E-06 2.45E-07 -1.04E-08 2.24E-10 S13 -2.00E+02 -1.34E-03 -1.63E-05 -7.27E-07 -1.72E-08 3.66E-10 S14 -4.73E+01 -7.53E-04 -1.42E-06 4.09E-08 1.26E-09 -2.60E-12
[0101] Figure 2The F-Tan (Theta) distortion curve of Example 1 is shown, which represents the distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the distortion of the optical lens 100 is controlled within -60% to 0, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.
[0102] Figure 3 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.38 throughout the entire field of view. Within the range of 0–120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.
[0103] Example 2
[0104] Please see Figure 4 The figure shows a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side surface S14 of the seventh lens L7 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.
[0105] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.
[0106] Table 2-1
[0107]
[0108] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.
[0109] Table 2-2
[0110] Face number K B C D E F S7 -1.31E+00 1.55E-04 4.09E-08 2.16E-07 -1.03E-08 2.40E-10 S8 -2.81E+00 4.42E-05 -2.53E-07 2.28E-07 -1.16E-08 2.87E-10 S13 2.00E+02 -9.30E-04 -8.52E-06 -5.35E-07 1.57E-08 -5.79E-10 S14 -2.00E+02 -8.32E-04 3.99E-06 -1.68E-07 4.07E-09 -5.15E-11
[0111] from Figure 5 As can be seen, the distortion of the optical lens 200 is controlled within -65% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image.
[0112] from Figure 6 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.
[0113] Example 3
[0114] Please see Figure 7 The figure shown is a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side S6 of the third lens L3 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.
[0115] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.
[0116] Table 3-1
[0117]
[0118] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.
[0119] Table 3-2
[0120]
[0121]
[0122] from Figure 8 As can be seen, the distortion of the optical lens 300 is controlled within -60% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image.
[0123] from Figure 9 As can be seen, the MTF value of this embodiment is above 0.28 throughout the entire field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.
[0124] Example 4
[0125] Please see Figure 10 The figure shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side surface S5 of the third lens L3 is concave; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.
[0126] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.
[0127] Table 4-1
[0128]
[0129] The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.
[0130] Table 4-2
[0131]
[0132]
[0133] from Figure 11 As can be seen, the distortion of the optical lens 400 is controlled within -70% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image.
[0134] from Figure 12 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.
[0135] Example 5
[0136] Please see Figure 13 The figure shown is a schematic diagram of the structure of the optical lens 500 provided in Embodiment 5 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side surface S5 of the third lens L3 is concave, the image side surface S14 of the seventh lens L7 is convex, and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.
[0137] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.
[0138] Table 5-1
[0139]
[0140] The surface profile parameters of the aspherical lens of the optical lens 500 in Example 5 are shown in Table 5-2.
[0141] Table 5-2
[0142] Face number K B C D E F S7 -5.62E-01 1.04E-04 3.02E-06 2.48E-08 7.79E-11 5.41E-11 S8 6.38E+00 2.37E-04 2.26E-06 2.57E-07 -1.15E-08 3.65E-10 S13 -2.00E+02 -9.05E-04 -1.13E-05 -2.62E-08 -1.22E-08 2.36E-10 S14 6.13E+01 -6.02E-04 -2.09E-06 7.10E-08 -9.44E-10 1.24E-11
[0143] from Figure 14 As can be seen, the distortion of the optical lens 500 is controlled within -70% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image.
[0144] from Figure 15 As can be seen, the MTF value of this embodiment is above 0.28 throughout the entire field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.
[0145] Please refer to Table 6 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, maximum field of view FOV, and the values corresponding to each conditional expression in each embodiment.
[0146] Table 6
[0147]
[0148]
[0149] In summary, the optical lens provided by the present invention employs eight lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as ultra-wide angle, large image plane, large aperture, and high imaging quality.
[0150] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0151] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.
Claims
1. An optical lens, eight pieces of lenses in total, characterized in that, In order from the object side to the imaging plane along the optical axis, successively comprise: a first lens with negative refractive power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a second lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface; a third lens with positive refractive power; a fourth lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a fifth lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a sixth lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface; a seventh lens with positive refractive power, the object side surface of which is a convex surface; an eighth lens with positive refractive power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; wherein the object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: -0.7<(R7+R8) / (R7-R8)<-0.3; the object side surface curvature radius R15 of the eighth lens and the image side surface curvature radius R16 of the eighth lens satisfy: 0.4<(R15-R16) / (R15+R16)<0.7; the object side surface aperture diameter d1 of the first lens, the real image height IH corresponding to the maximum field angle FOV of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.44<d1 / (IH / 2) / tan(FOV / 2)<0.57; the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -1.2<f123 / f45678<-0.
6.
2. The optical lens of claim 1, wherein, The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 7<TTL / f<8.5; the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 3<TTL / IH<3.
5.
3. The optical lens of claim 1, wherein, The maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 80°<FOV / Fno<100°; the real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.6<IH / EPD<4.
5.
4. The optical lens of claim 1, wherein, The real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.2<IH / f<2.6; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.89<BFL / f<0.
92.
5. The optical lens of claim 1, wherein, A radius of curvature R7 of an object side surface of the fourth lens and a radius of curvature R8 of an image side surface of the fourth lens satisfy: -0.65 < (R7+R8) / (R7-R8) < -0.36; a radius of curvature R15 of an object side surface of the eighth lens and a radius of curvature R16 of an image side surface of the eighth lens satisfy: 0.47 < (R15-R16) / (R15+R16) < 0.69; a combined focal length f123 of the first lens, the second lens and the third lens and a combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -1.12 < f123 / f45678 < -0.
68.
6. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f1 of the first lens satisfy: -2.8 < f1 / f < -1.9; the effective focal length f of the optical lens and a focal length f3 of the third lens satisfy: 3.2 < f3 / f < 10.
7. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f2 of the second lens satisfy: -3.1 < f2 / f < -1.9; a radius of curvature R3 of an object side surface of the second lens and a radius of curvature R4 of an image side surface of the second lens satisfy: -0.7 < (R3+R4) / (R3-R4) < 0.
2.
8. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f4 of the fourth lens satisfy: 1.8 < f4 / f < 2.85; a radius of curvature R7 of an object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 1.3 < R7 / f < 2.3; a radius of curvature R8 of an image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -7.5 < R8 / f < -3.
6.
9. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f5 of the fifth lens satisfy: 1.3 < f5 / f < 2.2; a radius of curvature R9 of an object side surface of the fifth lens and a radius of curvature R10 of an image side surface of the fifth lens satisfy: -0.2 < (R9+R10) / (R9-R10) < 0.
2.
10. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f8 of the eighth lens satisfy: 13 < f8 / f < 19; a radius of curvature R15 of an object side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -55 < R15 / f < -26; a radius of curvature R16 of an image side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -11 < R16 / f < -8.
Citation Information
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