Optical lens
By employing a specific design with a six-lens structure, the optical power and surface shape of the lens are optimized, solving the problem of poor imaging performance in automotive forward-looking cameras and achieving high-quality imaging performance suitable for autonomous driving systems.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANGXI LIANCHUANG ELECTRONICS CO LTD
- Filing Date
- 2025-04-27
- Publication Date
- 2026-05-12
AI Technical Summary
In the existing technology, the optical lenses of vehicle-mounted forward-looking cameras have poor imaging performance in complex driving environments, making it difficult to meet the high-precision imaging requirements of autonomous driving systems.
It adopts a six-lens structure, including lens design with specific optical power and surface shape. Through reasonable allocation of optical power and matching of surface shape, the imaging quality of the optical lens is optimized and aberrations are reduced.
It improves the imaging quality of the optical lens, achieving a large target area, large aperture, and small distortion, and enhances imaging stability and efficiency in complex driving environments.
Smart Images
Figure CN120335111B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of imaging lenses, and in particular to an optical lens. Background Technology
[0002] In today's booming development of automotive driver assistance and autonomous driving technologies, in-vehicle cameras play a crucial role. There are various types of in-vehicle cameras, including interior, rear, front, side, and surround view cameras. Each has unique functions and different application scenarios. For example, the main function of a front-view wide-angle camera is to accurately identify nearby objects, providing crucial information for driving in urban road conditions and low-speed driving scenarios.
[0003] The forward-facing camera is a core component of ADAS (Advanced Driver Assistance Systems). It not only bears the crucial responsibility of distance measurement but also accurately identifies objects and clearly distinguishes road markings. Therefore, the required visual algorithms are extremely complex, posing a high technical barrier. To fully utilize the performance of the forward-facing camera, developing an optical lens with superior imaging capabilities is of paramount importance. Only in this way can we ensure its stable and efficient operation in complex driving environments, laying a solid foundation for the further development of autonomous driving technology. Summary of the Invention
[0004] To address the aforementioned problems, the present invention aims to provide an optical lens with the advantage of excellent image quality.
[0005] The technical solution adopted in this invention is as follows:
[0006] An optical lens comprises six lenses, arranged sequentially along the optical axis from the object side to the imaging plane:
[0007] The first lens with negative optical power has a concave object side and a convex image side.
[0008] A second lens with negative optical power has a concave image-side surface;
[0009] A third lens with positive optical power has a convex object-side surface and a convex image-side surface.
[0010] The fourth lens with positive optical power has a concave object side and a convex image side.
[0011] The fifth lens with negative optical power has a concave object side and a concave image side.
[0012] A sixth lens with positive optical power;
[0013] Wherein, the object-side radius of curvature R7 of the fourth lens and the image-side radius of curvature R8 of the fourth lens satisfy: 1.2 < (R7 + R8) / (R7 - R8) < 1.34.
[0014] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.2 < TTL / f < 5.6; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 4.9 < TTL / IH < 5.1.
[0015] Further preferably, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 39° < FOV / Fno < 41°; the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.7 < IH / EPD < 1.8.
[0016] Further preferably, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1 < IH / f < 1.15; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.65 < BFL / f < 0.95.
[0017] Further preferably, the clear aperture semi-diameter 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: 2.3 < d1 / (IH / 2) / tan(FOV / 2) < 3.2; the combined focal length f12 of the first lens and the second lens and the combined focal length f3456 of the third lens, the fourth lens, the fifth lens, and the sixth lens satisfy: -1.8 < f12 / f3456 < -1.1.
[0018] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -14 < f1 / f < -7.4; the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: -0.36 < (R1 - R2) / (R1 + R2) < -0.27.
[0019] Further preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1 < f3 / f < 1.4; the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: -1093 < (R5 - R6) / (R5 + R6) < -17.
[0020] More preferably, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f4 / f < 1.4; the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -9.7 < R7 / f < -7.1; the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -1.2 < R8 / f < -0.9.
[0021] More preferably, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -0.64 < f5 / f < -0.55; 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: |(R9 + R10) / (R9 - R10)| < 0.14.
[0022] More preferably, the sagittal height Sag7 of the object side clear aperture of the fourth lens and the object side clear aperture diameter d7 of the fourth lens satisfy: -0.06 < Sag7 / d7 < -0.03; the sagittal height Sag8 of the image side clear aperture of the fourth lens and the image side clear aperture diameter d8 of the fourth lens satisfy: -0.43 < Sag8 / d8 < -0.39.
[0023] The optical lens provided by the present invention adopts six lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberration, and enhance the imaging quality of the optical lens, endowing the lens with one or more advantages such as a large target surface, a large aperture, and small distortion. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, where:
[0025] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.
[0026] Figure 2 is a field curvature curve graph of the optical lens in Embodiment 1 of the present invention.
[0027] Figure 3 is an F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 1 of the present invention.
[0028] Figure 4 is an MTF curve graph of the optical lens in Embodiment 1 of the present invention.
[0029] Figure 5 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.
[0030] Figure 6This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.
[0031] Figure 7 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.
[0032] Figure 8 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.
[0033] Figure 9 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.
[0034] Figure 10 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.
[0035] Figure 11 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.
[0036] Figure 12 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.
[0037] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation
[0038] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.
[0039] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.
[0040] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.
[0041] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.
[0042] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.
[0043] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.
[0044] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.
[0045] The optical lens provided in this embodiment of the invention includes six 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, and a sixth lens.
[0046] In some embodiments, the first lens may have negative optical power, its object-side surface may be concave, and its image-side surface may be convex. The second lens may have negative optical power, its object-side surface may be convex or concave, and its image-side surface may be concave. The third lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be convex. The fourth lens may have positive optical power, its object-side surface may be concave, and its image-side surface may be convex. The fifth lens may have negative optical power, its object-side surface may be concave, and its image-side surface may be concave. The sixth lens may have positive optical power, its object-side surface may be convex or concave near the optical axis, and its image-side surface may be concave or convex near the optical axis.
[0047] In some embodiments, the optical lens may further include an aperture, which may be located between the second lens and the third lens. It can be understood that the aperture is used to limit the amount of incident light to change the brightness of the image. When the aperture is located between the second lens and the third lens, it is convenient for correcting the aperture aberration.
[0048] In some embodiments, the optical lens may further include a filter and a protective glass, which are sequentially arranged along the optical axis between the sixth lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging. The protective glass plays a role in protecting the optical lens, preventing the photosensitive chip from being damaged, and can improve the shock resistance and scratch resistance of the optical lens, while having almost no impact on the imaging quality of the optical lens.
[0049] In some embodiments, the fourth lens and the fifth lens may be glued together to form a glued lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberration 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.
[0050] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 1.2 < (R7 + R8) / (R7 - R8) < 1.34. Meeting the above range, controlling the fourth lens to have an appropriate surface shape can effectively correct the aberration of the optical lens and improve the imaging quality.
[0051] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.2 < TTL / f < 5.6; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 4.9 < TTL / IH < 5.1. Meeting the above range is beneficial to achieving the balance of small volume and large image surface of the optical lens, making the lens have a smaller total length. More specifically: 5.21 < TTL / f < 5.51; 4.9 < TTL / IH < 5.02.
[0052] In some embodiments, the maximum field angle FOV of the optical lens and the f - number Fno of the optical lens satisfy: 39° < FOV / Fno < 41°; the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.7 < IH / EPD < 1.8. Meeting the above range, reasonably limiting the ratio of the field angle to the f - number can collect light at a large angle and obtain good imaging quality. At the same time, reasonably limiting the ratio of the image height to the entrance pupil diameter is beneficial to increasing the light - passing amount, making the brightness of the peripheral field and the central field more uniform. More specifically: 39.25° < FOV / Fno < 40.01°.
[0053] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1 < IH / f < 1.15; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.65 < BFL / f < 0.95. Meeting the above ranges and reasonably controlling the ratio of the image height to the focal length of the optical lens helps the optical lens to have a larger image plane. At the same time, limiting the optical lens to have an appropriate back focus facilitates the reasonable arrangement of the positions of each lens and reduces the processing and assembly difficulty. More specifically: 1.05 < IH / f < 1.11; 0.67 < BFL / f < 0.94.
[0054] In some embodiments, the clear aperture radius d1 on the object side 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: 2.3 < d1 / (IH / 2) / tan(FOV / 2) < 3.2; the combined focal length f12 of the first lens and the second lens and the combined focal length f3456 of the third lens, the fourth lens, the fifth lens, and the sixth lens satisfy: -1.8 < f12 / f3456 < -1.1. Meeting the above ranges can reasonably arrange the overall geometry of the optical lens and improve its structural stability. At the same time, making the optical power of the front and rear lens groups of the optical lens within a suitable range can reduce the difficulty of lens aberration correction and improve the imaging quality of the optical lens. More specifically: 2.34 < d1 / (IH / 2) / tan(FOV / 2) < 3.18; -1.77 < f12 / f3456 < -1.11.
[0055] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -14 < f1 / f < -7.4; the curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side of the first lens satisfy: -0.36 < (R1 - R2) / (R1 + R2) < -0.27. Meeting the above ranges, by reasonably limiting the proportion of the optical power of the first lens and its surface shape, the light passing through it can be diverged, which is beneficial to achieving a small front aperture. More specifically: -13.32 < f1 / f < -7.41.
[0056] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1 < f3 / f < 1.4; the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: -1093 < (R5 - R6) / (R5 + R6) < -17. Satisfying the above ranges, by reasonably defining the proportion of the optical power of the third lens and its surface shape, the aberration generated at the front end of the lens can be effectively corrected, and the imaging quality of the lens can be improved. More specifically: 1.07 < f3 / f < 1.32; -1092.07 < (R5 - R6) / (R5 + R6) < -17.95.
[0057] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f4 / f < 1.4; the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -9.7 < R7 / f < -7.1; the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -1.2 < R8 / f < -0.9. Satisfying the above ranges, by reasonably defining the proportion of the optical power of the fourth lens and its surface shape, the aberration of the optical lens can be effectively corrected, and the imaging quality can be improved. More specifically: 1.06 < f4 / f < 1.34; -9.68 < R7 / f < -7.14; -1.11 < R8 / f < -0.9.
[0058] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -0.64 < f5 / f < -0.55; 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: |(R9 + R10) / (R9 - R10)| < 0.14. Satisfying the above ranges, by reasonably defining the proportion of the optical power of the fifth lens and its surface shape, the spherical aberration can be optimized, and high-quality imaging can be achieved. More specifically: -0.14 < (R9 + R10) / (R9 - R10) < 0.11.
[0059] In some embodiments, the sagittal height Sag7 of the object side clear aperture of the fourth lens and the clear aperture d7 of the object side of the fourth lens satisfy: -0.06 < Sag7 / d7 < -0.03; the sagittal height Sag8 of the image side clear aperture of the fourth lens and the clear aperture d8 of the image side of the fourth lens satisfy: -0.43 < Sag8 / d8 < -0.39. Satisfying the above ranges helps to control the light path and highlight the detailed information of the central field of view of the optical lens.
[0060] In some embodiments, the sum ΣCT of the central thicknesses of the first lens to the sixth lens along the optical axis and the overall optical length TTL of the optical lens satisfy: 0.3 < ΣCT / TTL < 0.47. Meeting the above range and controlling the overall optical length of the optical lens and the sum of the central thicknesses of each lens within a reasonable range helps to achieve high pixel characteristics and improve the imaging quality of the optical lens.
[0061] In some embodiments, the sum ΣCT of the central thicknesses of the first lens to the sixth lens along the optical axis and the effective focal length f of the optical lens satisfy: 1.7 < ΣCT / f < 2.5. Meeting the above range and controlling the effective focal length of the optical lens and the sum of the central thicknesses of each lens within a reasonable range can make the lens more compact. More specifically: 1.71 < ΣCT / f < 2.47.
[0062] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.2 < f2 / f < -2. Meeting the above range and reasonably limiting the proportion of the optical power of the second lens is beneficial to achieving a larger light entrance amount and increasing the relative illumination. More specifically: -3.15 < f2 / f < -2.05.
[0063] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 1.5 < f6 / f < 6.8. Meeting the above range and reasonably limiting the proportion of the optical power of the sixth lens 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, and being beneficial to improving the illumination of the edge field of view. More specifically: 1.55 < f6 / f < 6.73.
[0064] In some embodiments, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: -2.6 < f12 / f < -1.5. Meeting the above range and making the proportion of the optical power of the front lens group of the optical lens within a suitable range can diverge light, helping to obtain a large field of view angle and thus expanding the imaging range. More specifically: -2.51 < f12 / f < -1.56.
[0065] In some embodiments, the combined focal length f3456 of the third lens, the fourth lens, the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 1.2 < f3456 / f < 1.5. Meeting the above range and making the proportion of the optical power of the rear lens group of the optical lens within a suitable range can converge light, reduce the difficulty of lens aberration correction, and improve the imaging quality of the optical lens. More specifically: 1.28 < f3456 / f < 1.43.
[0066] In some embodiments, the radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -4.1 < R1 / f < -2.4; the radius of curvature R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: -8.2 < R2 / f < -4.3. Satisfying the above ranges, controlling the first lens to have an appropriate surface shape can have a diverging effect on the light passing through it, which is beneficial to achieving a small front aperture. More specifically: -4.06 < R1 / f < -2.44; -8.12 < R2 / f < -4.3.
[0067] In some embodiments, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 0.48 < R1 / R2 < 0.58. Satisfying the above ranges, controlling the first lens to have an appropriate surface shape can have a diverging effect on the light passing through it, which is beneficial to achieving a small front aperture.
[0068] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 7 < R7 / R8 < 10.6. Satisfying the above ranges, controlling the fourth lens to have an appropriate surface shape can effectively correct the aberration of the optical lens and improve the imaging quality. More specifically: 7.06 < R7 / R8 < 10.58.
[0069] In some embodiments, the optical lens satisfies the following conditional expressions: 6.8 mm < f < 7.3 mm; 63° < FOV < 65°; 4.2 mm < EPD < 4.5 mm; 37 mm < TTL < 39 mm; 1.55 < Fno < 1.65; 7.5 mm < IH < 7.8 mm; 12° < CRA < 18°; 4.8 mm < BFL < 6.8 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field angle of the optical lens, CRA represents the main ray incident angle at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. Satisfying the above ranges, the optical lens has at least one or more advantages such as a large target surface, a large aperture, and small distortion. More specifically: 6.89 mm < f < 7.24 mm; 63.9° < FOV < 64.1°; 4.22 mm < EPD < 4.45 mm; 37.79 mm < TTL < 38.01 mm; 1.59 < Fno < 1.64; 7.55 mm < IH < 7.71 mm; 12.99° < CRA < 17.02°; 4.83 mm < BFL < 6.73 mm.
[0070] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens is made of plastic, production costs can be effectively reduced. Conversely, when the lens is made of glass, the low dispersion characteristic of glass itself can effectively correct geometric chromatic aberration of the optical system. The optical lens provided by the present invention can employ an all-glass lens structure, which can reduce dispersion, effectively correct chromatic aberration of the optical lens, and improve image quality.
[0071] In some embodiments, the first, second, third, fourth, fifth, and sixth 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 third and sixth lenses of this invention are aspherical lenses, while the first, second, fourth, and fifth lenses are spherical lenses.
[0072] 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:
[0073]
[0074] 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.
[0075] 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.
[0076] Example 1
[0077] 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 surface, the following components in sequence: a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a filter G1, and a protective glass G2.
[0078] Among them, the first lens L1 has negative optical power, its object side S1 is concave, and its image side S2 is convex.
[0079] The second lens L2 has negative optical power, its object side S3 is convex, and its image side S4 is concave.
[0080] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is convex.
[0081] The fourth lens L4 has positive optical power, its object side S7 is concave, and its image side S8 is convex.
[0082] The fifth lens L5 has negative optical power, its object side S8 is concave, and its image side S9 is concave.
[0083] The fourth lens L4 and the fifth lens L5 form a cemented lens group, that is, the cemented surface of the image side of the fourth lens L4 and the object side of the fifth lens L5 is S8.
[0084] The sixth lens L6 has positive optical power, its object side S10 is convex, and its image side S11 is concave.
[0085] The object-side surface S12 and the image-side surface S13 of the filter G1 are both planar.
[0086] The object side S14 and image side S15 of the protective glass G2 are both flat.
[0087] The imaging plane S16 is a plane.
[0088] The third lens L3 and the sixth lens L6 are glass aspherical lenses, while the first lens L1, the second lens L2, the fourth lens L4, and the fifth lens L5 are glass spherical lenses.
[0089] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.
[0090] Table 1-1
[0091]
[0092]
[0093] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.
[0094] Table 1-2
[0095] Face number K B C D E F S5 -2.14E-01 -1.07E-04 -9.07E-07 -3.32E-08 1.03E-09 -1.99E-11 S6 -6.04E+00 -1.41E-04 4.46E-06 -1.30E-07 2.37E-09 -2.66E-11 S10 3.68E-01 1.58E-04 -3.23E-05 -1.68E-06 9.02E-08 -4.22E-09 S11 2.86E+01 6.22E-04 -2.22E-05 2.45E-07 -1.14E-07 1.30E-09
[0096] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4As shown.
[0097] Figure 2 The field curvature curve of Embodiment 1 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.02 mm, indicating that the optical lens 100 can effectively correct the field curvature.
[0098] Figure 3 The 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 is controlled within -15% to 0%, indicating that the optical lens 100 can effectively correct distortion.
[0099] Figure 4 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 0.6 throughout the entire field of view. Within the range of 0–120 lp / mm, the MTF curve decreases smoothly and uniformly 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.
[0100] Example 2
[0101] Please see Figure 5 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 object side surface S3 of the second lens L2 is concave; the image side surface S11 of the sixth lens L6 is convex near the optical axis; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.
[0102] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.
[0103] Table 2-1
[0104]
[0105] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.
[0106] Table 2-2
[0107] Face number K B C D E F S5 -7.37E-01 -8.80E-05 8.41E-08 -3.03E-08 1.29E-09 -2.47E-11 S6 -5.42E+00 -1.59E-04 4.33E-06 -1.15E-07 2.38E-09 -3.06E-11 S10 1.08E+00 6.24E-04 -4.30E-06 -8.04E-07 5.26E-08 -1.02E-09 S11 1.69E+01 1.37E-03 1.69E-05 1.73E-07 4.25E-08 1.28E-09
[0108] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 As shown. From Figure 6 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.03mm to 0.02mm, indicating that the optical lens 200 can effectively correct field curvature. From Figure 7 As can be seen, the distortion of optical lens 200 is controlled within -15% to 0%, indicating that optical lens 200 can effectively correct distortion. From... Figure 8 As can be seen, the MTF value of this embodiment is above 0.5 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.
[0109] Example 3
[0110] Please see Figure 9 The figure shows 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 object side surface S10 of the sixth lens L6 is concave near the optical axis, and the image side surface S11 is convex near the optical axis; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.
[0111] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.
[0112] Table 3-1
[0113]
[0114] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.
[0115] Table 3-2
[0116]
[0117]
[0118] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 300 are respectively as follows: Figure 10 , Figure 11 , Figure 12 As shown. From Figure 10As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.05mm to 0.02mm, indicating that the optical lens 300 can effectively correct field curvature. From Figure 11 As can be seen, the distortion of optical lens 300 is controlled within -15% to 0%, indicating that optical lens 300 can effectively correct distortion. From... Figure 12 As can be seen, the MTF value of this embodiment is above 0.4 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.
[0119] Please refer to Table 4 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, principal ray incident angle CRA at maximum image height, true image height IH corresponding to maximum field of view, maximum field of view FOV, entrance pupil diameter EPD, back focal length BFL, and the values corresponding to each conditional expression in each embodiment.
[0120] Table 4
[0121]
[0122]
[0123] In summary, the optical lens provided by the present invention uses six 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 large target surface, large aperture, and small distortion.
[0124] 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.
[0125] 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 comprising six lenses, characterized in that, It successively includes from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side is concave and whose image side is convex; A second lens with a negative optical power, whose image side is concave; A third lens with a positive optical power, whose object side is convex and whose image side is convex; A fourth lens with a positive optical power, whose object side is concave and whose image side is convex; A fifth lens with a negative optical power, whose object side is concave and whose image side is concave; A sixth lens with a positive optical power; Wherein, the radius of curvature R7 of the object side of the fourth lens and the radius of curvature R8 of the image side of the fourth lens satisfy: 1.2 < (R7 + R8) / (R7 - R8) < 1.34; The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.2 < TTL / f < 5.6; The overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 4.9 < TTL / IH < 5.1; The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -14 < f1 / f < -7.4; The maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 39° < FOV / Fno < 41°; 2. The optical lens according to claim 1, characterized in that, The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.21 < TTL / f < 5.51; The overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 4.9 < TTL / IH < 5.02; The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -13.32 < f1 / f < -7.41; 3. The optical lens according to claim 1, characterized in that, The maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 39.29° ≤ FOV / Fno ≤ 40°; The true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.7 < IH / EPD < 1.8; 4. The optical lens according to claim 1, characterized in that, The true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1 < IH / f < 1.15; The back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.65 < BFL / f < 0.95; 5. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter d1 of the object side 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: 2.3 < d1 / (IH / 2) / tan(FOV / 2) < 3.2; The combined focal length f12 of the first lens and the second lens and the combined focal length f3456 of the third lens, the fourth lens, the fifth lens and the sixth lens satisfy: -1.8 < f12 / f3456 < -1.1; 6. The optical lens according to claim 1, characterized in that, The radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side of the first lens satisfy: -0.36 < (R1 - R2) / (R1 + R2) < -0.27; 7. The optical lens according to claim 1, characterized in that, The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1 < f3 / f < 1.4; the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: -1093 < (R5 - R6) / (R5 + R6) < -17.
8. The optical lens according to claim 1, characterized in that, The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f4 / f < 1.4; the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -9.7 < R7 / f < -7.1; the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -1.2 < R8 / f < -0.
9.
9. The optical lens according to claim 1, characterized in that, The focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -0.64 < f5 / f < -0.55; 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: |(R9 + R10) / (R9 - R10)| < 0.
14.
10. The optical lens according to claim 1, characterized in that, The sagittal height Sag7 of the object side clear aperture of the fourth lens and the object side clear aperture d7 of the fourth lens satisfy: -0.06 < Sag7 / d7 < -0.03; the sagittal height Sag8 of the image side clear aperture of the fourth lens and the image side clear aperture d8 of the fourth lens satisfy: -0.43 < Sag8 / d8 < -0.39.