Optical lens

Abstract

The invention provides an optical lens, which comprises six lenses from an object side to an imaging surface along an optical axis: a first lens with positive focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power and a fifth lens with positive focal power, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; the object side surface of the third lens is a convex surface; the fourth lens has negative focal power; the fifth lens has focal power; the sixth lens has negative focal power; wherein the curvature radius R4 of the image side surface of the second lens and the curvature radius R5 of the object side surface of the third lens meet the formula: (R4 + R5) / (R4-R5) lt; 1. According to the optical lens provided by the invention, the six lenses with specific focal power are adopted, and through specific surface shape matching and reasonable focal power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, the imaging quality of the optical lens can be improved, and the lens has one or more advantages of long focus, large target surface, high imaging quality and the like.

Description

Technical Field

[0001] This invention relates to the technical field of imaging lenses, and in particular to an optical lens. Background Technology

[0002] As people's demands for driving experience continue to increase, automotive optical lenses are being used more and more in intelligent driving, and the status of automotive optical lenses in the automotive industry is constantly rising.

[0003] Advanced Driver Assistance Systems (ADAS) play a crucial role in intelligent driving. They use various lenses and sensors to collect environmental information to ensure driver safety. Existing ADAS lenses not only require a slim and compact design with high pixel count and high resolution, but also need to produce clear images in low-light conditions. Therefore, it is necessary to develop an optical lens with excellent imaging performance. 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] A first lens with positive optical power has a convex object-side surface.

[0008] A second lens with positive optical power has a concave object side and a convex image side.

[0009] A third lens with positive optical power has a convex object-side surface;

[0010] A fourth lens with negative optical power;

[0011] A fifth lens with optical power;

[0012] A sixth lens with negative optical power;

[0013] Wherein, the radius of curvature R4 of the image side of the second lens and the radius of curvature R5 of the object side of the third lens satisfy: |(R4+R5) / (R4-R5)|<1.

[0014] Further preferably, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 10° < FOV / Fno < 18°; the total optical length TTL of the optical lens, the maximum field of view FOV of the optical lens, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 84 < 180°×TTL / IH / FOV < 135.

[0015] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.3 < f3 / f < 1.3; the effective focal length f of the optical lens and the curvature radius R5 of the object side surface of the third lens satisfy: R5 / f > 0.4.

[0016] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -5.6 < f4 / f < -0.5; the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: 0.3 < R7 / R8 < 8.8.

[0017] Further preferably, the effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: 1.3 < f12 / f < 5; the effective focal length f of the optical lens and the combined focal length f3456 of the third lens, the fourth lens, the fifth lens, and the sixth lens satisfy: 1.3 < f3456 / f < 3.6.

[0018] Further preferably, the effective focal length f of the optical lens and the curvature radius R3 of the object side surface of the second lens satisfy: -1 < R3 / f < -0.4; the effective focal length f of the optical lens and the curvature radius R4 of the image side surface of the second lens satisfy: -1.1 < R4 / f < -0.5.

[0019] Further preferably, the curvature radius R4 of the image side surface of the second lens and the curvature radius R5 of the object side surface of the third lens satisfy: -2.1 < R4 / R5 < 0; the curvature radius R3 of the object side surface of the second lens and the curvature radius R5 of the object side surface of the third lens satisfy: -1.8 < R3 / R5 < 0.

[0020] Further preferably, 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: -26.7 < (R3 + R4) / (R3 - R4) < -7.9.

[0021] Further preferably, the curvature radius R3 of the object side surface of the second lens and the curvature radius R5 of the object side surface of the third lens satisfy: |(R3 + R5) / (R3 - R5)| < 1.

[0022] Further preferably, the sagittal height Sag3 of the clear aperture semi-diameter on the object side of the second lens and the clear aperture semi-diameter d3 of the object side of the second lens satisfy: -0.3 < Sag3 / d3 < -0.1; the sagittal height Sag4 of the clear aperture semi-diameter on the image side of the second lens and the clear aperture semi-diameter d4 of the image side of the second lens satisfy: -0.3 < Sag4 / d4 < -0.1; the sagittal height Sag5 of the clear aperture semi-diameter on the object side of the third lens and the clear aperture semi-diameter d5 of the object side of the third lens satisfy: d5 / Sag5 > 3.3.

[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 aberrations, and enhance the imaging quality of the optical lens, endowing the lens with one or more advantages such as long focal length, large target surface, and high imaging quality. Brief Description of the Drawings

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and easy to understand from the description of the embodiments in conjunction with the following 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 F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 3 is a MTF curve graph of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 4 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0029] Figure 5 is a F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 2 of the present invention.

[0030] Figure 6 is a MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 7 is a schematic structural diagram of the optical lens in Embodiment 3 of the present invention.

[0032] Figure 8 is a F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 3 of the present invention.

[0033] Figure 9 is a MTF curve graph of the optical lens in Embodiment 3 of the present invention.

[0034] Figure 10 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0035] Figure 11 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 4 of the present invention.

[0036] Figure 12 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0037] Figure 13 This is a schematic diagram of the optical lens structure in Embodiment 5 of the present invention.

[0038] Figure 14 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 5 of the present invention.

[0039] Figure 15 This is the MTF curve of the optical lens in Embodiment 5 of the present invention.

[0040] Figure 16 This is a schematic diagram of the optical lens in Embodiment 6 of the present invention.

[0041] Figure 17 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 6 of the present invention.

[0042] Figure 18 This is the MTF curve of the optical lens in Embodiment 6 of the present invention.

[0043] Figure 19 This is a schematic diagram of the optical lens in Embodiment 7 of the present invention.

[0044] Figure 20 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 7 of the present invention.

[0045] Figure 21 This is the MTF curve of the optical lens in Embodiment 7 of the present invention.

[0046] Figure 22 This is a schematic diagram of the optical lens in Embodiment 8 of the present invention.

[0047] Figure 23 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 8 of the present invention.

[0048] Figure 24 This is the MTF curve of the optical lens in Embodiment 8 of the present invention.

[0049] Figure 25 This is a schematic diagram of the optical lens structure in Embodiment 9 of the present invention.

[0050] Figure 26 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 9 of the present invention.

[0051] Figure 27 This is the MTF curve of the optical lens in Embodiment 9 of the present invention.

[0052] Figure 28 This is a schematic diagram of the optical lens in Embodiment 10 of the present invention.

[0053] Figure 29 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 10 of the present invention.

[0054] Figure 30 This is the MTF curve of the optical lens in Embodiment 10 of the present invention.

[0055] Figure 31 This is a schematic diagram of the optical lens structure in Embodiment 11 of the present invention.

[0056] Figure 32 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 11 of the present invention.

[0057] Figure 33 This is the MTF curve of the optical lens in Embodiment 11 of the present invention.

[0058] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] In some embodiments, the first lens may have positive optical power, its object-side surface is convex, and its image-side surface may be concave or convex. The second lens may have positive optical power, its object-side surface is concave, and its image-side surface is convex. The third lens may have positive optical power, its object-side surface is convex, and its image-side surface may be concave or convex. The fourth lens may have negative optical power, its object-side surface may be concave or convex, and its image-side surface may be concave or convex. The fifth lens may have positive or negative optical power, its object-side surface may be concave or convex, and its image-side surface may be concave or convex. The sixth lens may have negative optical power, its object-side surface may be concave or convex, and its image-side surface may be concave or convex.

[0068] 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.

[0069] In some embodiments, the optical lens may further include a filter, which may be disposed between the sixth lens and the imaging surface. The filter is used to filter out interfering light and prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0070] In some embodiments, the third lens and the fourth lens may be glued together to form a cemented 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.

[0071] In some embodiments, the radius of curvature R4 of the image side surface of the second lens and the radius of curvature R5 of the object side surface of the third lens satisfy: |(R4 + R5) / (R4 - R5)| < 1. Satisfying the above range is beneficial to obtaining a symmetric surface shape between the image side surface of the second lens and the object side surface of the third lens, beneficial to correcting various aberrations of the optical lens, and improving the imaging quality of the optical lens. More specifically, -0.98 < (R4 + R5) / (R4 - R5) < 0.32.

[0072] In some embodiments, the maximum field of view FOV of the optical lens and the f-number Fno of the optical lens satisfy: 10° < FOV / Fno < 18°. Satisfying the above range limits that the optical lens has an appropriate field of view and f-number, can collect light at a large angle and obtain good imaging quality. More specifically, 11.8° < FOV / Fno < 16.9°.

[0073] In some embodiments, the total optical length TTL of the optical lens, the maximum field of view FOV of the optical lens, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 84 < 180°×TTL / IH / FOV < 135. Satisfying the above range is beneficial to balancing the relationship among the total length, image height, and field of view of the optical lens. More specifically, 85.43 < 180°×TTL / IH / FOV < 134.22.

[0074] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.3 < f3 / f < 1.3; the effective focal length f of the optical lens and the curvature radius R5 of the object side surface of the third lens satisfy: R5 / f > 0.4. Meeting the above ranges, by reasonably setting the focal length and surface shape of the third lens, it is beneficial to further converge the light rays, enable the converged light rays to smoothly enter the rear optical system, reduce the difficulty of correcting the marginal field distortion, and improve the overall imaging quality. More specifically, 0.41 < f3 / f < 1.14; 0.47 < R5 / f < 63.51.

[0075] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -5.6 < f4 / f < -0.5; the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: 0.3 < R7 / R8 < 8.8. Meeting the above ranges, by reasonably setting the focal length and surface shape of the fourth lens, the positive spherical aberration generated by the fourth negative lens can be balanced with the negative spherical aberration generated by the previous positive lenses, improving the overall imaging quality. At the same time, the trend of the light rays can be reasonably controlled to avoid the problem of excessive lens sensitivity caused by excessive light ray deflection. More specifically, -5.09 < f4 / f < -0.6; 0.32 < R7 / R8 < 7.93.

[0076] In some embodiments, the effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: 1.3 < f12 / f < 5; the effective focal length f of the optical lens and the combined focal length f3456 of the third lens, the fourth lens, the fifth lens, and the sixth lens satisfy: 1.3 < f3456 / f < 3.6. Meeting the above ranges, by reasonably limiting the focal lengths of the lens groups before and after the aperture, the aberration generated by the lens groups before and after the aperture can be effectively corrected, improving the imaging quality of the optical lens. More specifically, 1.47 < f12 / f < 4.55; 1.42 < f3456 / f < 3.27.

[0077] In some embodiments, the effective focal length f of the optical lens and the curvature radius R3 of the object side surface of the second lens satisfy: -1 < R3 / f < -0.4; the effective focal length f of the optical lens and the curvature radius R4 of the image side surface of the second lens satisfy: -1.1 < R4 / f < -0.5. Meeting the above ranges, by controlling the surface shape of the second lens, the light ray deflection angle can be reduced, making the light ray trend smoother and improving the imaging quality of the light ray lens. More specifically, -0.88 < R3 / f < -0.56; -0.99 < R4 / f < -0.65.

[0078] In some embodiments, the radius of curvature R4 of the image side surface of the second lens and the radius of curvature R5 of the object side surface of the third lens satisfy: -2.1 < R4 / R5 < 0; the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R5 of the object side surface of the third lens satisfy: -1.8 < R3 / R5 < 0. Meeting the above ranges is beneficial to slowing down the change degree of the refraction angle of the incident light and avoiding excessive aberration caused by too strong refraction change. More specifically, -1.9 < R4 / R5 < 0; -1.6 < R3 / R5 < 0.

[0079] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: -26.7 < (R3 + R4) / (R3 - R4) < -7.9. Meeting the above range can reduce the light deflection angle, make the light trend smoother; at the same time, it can correct coma and field curvature, improve the flatness of imaging, and enhance the imaging quality of the optical lens. More specifically, -24.3 < (R3 + R4) / (R3 - R4) < -8.8.

[0080] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R5 of the object side surface of the third lens satisfy: |(R3 + R5) / (R3 - R5)| < 1. Meeting the above range is beneficial to obtaining a symmetric surface shape between the object side surface of the second lens and the object side surface of the third lens, beneficial to the correction of various aberrations of the optical lens, and enhancing the imaging quality of the optical lens. More specifically, -0.99 < (R3 + R5) / (R3 - R5) < 0.24.

[0081] In some embodiments, the sagittal height Sag3 of the clear aperture of the object side surface of the second lens and the clear aperture diameter d3 of the object side surface of the second lens satisfy: -0.3 < Sag3 / d3 < -0.1; the sagittal height Sag4 of the clear aperture of the image side surface of the second lens and the clear aperture diameter d4 of the image side surface of the second lens satisfy: -0.3 < Sag4 / d4 < -0.1; the sagittal height Sag5 of the clear aperture of the object side surface of the third lens and the clear aperture diameter d5 of the object side surface of the third lens satisfy: d5 / Sag5 > 3.3. Meeting the above ranges helps to control the trend of the marginal field light and highlight the detailed information of the central field of the optical lens. More specifically, -0.23 < Sag3 / d3 < -0.17; -0.21 < Sag4 / d4 < -0.14; 3.6 < d5 / Sag5 < 452.4.

[0082] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.7 < TTL / f < 2.9. Meeting the above range is beneficial to limiting the overall length of the lens while better realizing the telephoto performance of the system. More specifically, 1.9 < TTL / f < 2.6.

[0083] In some embodiments, 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: 3.6 < TTL / IH < 5.2. Meeting the above range can preferably achieve the balance between the total length of the lens and the image plane. More specifically, 3.7 < TTL / IH < 4.9.

[0084] In some embodiments, 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: 0.8 < IH / EPD < 1.3. Meeting the above range can increase the width of the light beam entering the optical lens, improve the brightness at the image plane of the optical lens, and avoid the generation of vignetting. More specifically, 0.88 < IH / EPD < 1.16.

[0085] 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: 0.4 < IH / f < 0.7. Meeting the above range, controlling the image height and focal length of the optical lens within a reasonable range helps the optical lens to have the characteristics of a long focal length and a large image plane, and improves the imaging quality. More specifically, 0.45 < IH / f < 0.58.

[0086] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.25 < BFL / f < 0.55. Meeting the above range, limiting the optical lens to have a suitable back focus is convenient for reasonably arranging the positions of each lens, and at the same time reduces the processing and assembly difficulty. More specifically, 0.27 < BFL / f < 0.48.

[0087] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the sixth lens along the optical axis satisfy: 0.5 < ∑CT / TTL < 0.9. Meeting the above range, reasonably configuring the total optical length of the optical lens and the sum of the thicknesses of each lens helps to achieve the high-pixel characteristic and improve the imaging quality of the optical lens. More specifically, 0.57 < ∑CT / TTL < 0.74.

[0088] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.3 < f1 / f < 7.1. Meeting the above range, by setting the first lens to have a large positive refractive power, the incident light can be converged to a large extent, and more light can enter the system, which is beneficial to improving the light input of the lens, realizing the large aperture performance of the lens, and enabling the lens to achieve high-definition imaging in a relatively dark environment. More specifically, 1.45 < f1 / f < 6.5.

[0089] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: f2 / f > 4.2. Meeting the above range, which defines that the second lens has an appropriate positive optical power, is conducive to further converging light rays, making the light ray trend smoother, optimizing aberrations, and improving resolution. More specifically, 4.7 < f2 / f < 173.75.

[0090] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: f6 / f < -0.4. Meeting the above range, which defines that the sixth lens has a negative optical power, is conducive to increasing the imaging area of the optical lens, and at the same time can optimize the chromatic aberration of the optical lens and improve the imaging quality of the optical lens. More specifically, f6 / f < -0.47.

[0091] In some embodiments, 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: 0.4 < f12 / f3456 < 3.5. Meeting the above range, by reasonably defining the focal lengths of the lens groups before and after the aperture, the aberrations generated by the lens groups before and after the aperture can be effectively corrected, and the imaging quality of the optical lens can be improved. More specifically, 0.44 < f12 / f3456 < 3.18.

[0092] In some embodiments, 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 < 1. Meeting the above range, by reasonably setting the surface shape of the second lens, the deflection degree of the light rays entering the second lens can be effectively reduced, which is conducive to maintaining the miniaturization of the lens head, and at the same time enables the lens to have a larger aperture and increases the light flux entering the lens. More specifically, 0.79 < R3 / R4 < 0.93.

[0093] In some embodiments, the curvature radius R4 of the image side surface of the second lens and the focal length f2 of the second lens satisfy: -0.2 < R4 / f2 < 0; the curvature radius R3 of the object side surface of the second lens and the focal length f2 of the second lens satisfy: R3 / f2 < -7.2. Meeting the above range, the deflection angle of the light rays can be reduced, making the light ray trend smoother; at the same time, it can correct coma and field curvature, improve the flatness of imaging, and improve the imaging quality of the optical lens. More specifically, -0.15 < R4 / f2 < 0; -220.23 < R3 / f2 < -8.23.

[0094] In some embodiments, the focal length f3 of the third lens and the curvature radius R5 of the object side surface of the third lens satisfy: R5 / f3 > 0.4. By satisfying the above range and reasonably controlling the ratio of the curvature radius of the object side surface of the third lens to the focal length of the third lens, the light deflection angle can be reduced, making the light path more stable; at the same time, the difficulty of aberration correction for the rear lens is reduced. More specifically, 0.53 < R5 / f3 < 88.89.

[0095] In some embodiments, the optical lens satisfies the following conditional expressions: 11.2 mm < f < 19.2 mm; 23° < FOV < 36°; 5.7 mm < EPD < 9.9 mm; 29 mm < TTL < 37 mm; 1.6 < Fno < 2.4; 5.7 mm < IH < 10.2 mm; 13° < CRA < 23°; 3.5 mm < BFL < 7.3 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field of view 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 of view angle of the optical lens, CRA represents the chief ray incident angle of the optical lens, and BFL represents the back focal length of the optical lens. By satisfying the above range, the optical lens has at least one or more advantages such as a large target surface, a large aperture, and a long focal length. More specifically, 12.45 mm < f < 17.53 mm; 6.34 mm < EPD < 9.02 mm; 30.99 mm < TTL < 35.01 mm; 1.79 < Fno < 2.21; 14.44° < CRA < 20.75°; 4.05 mm < BFL < 6.72 mm; 25.99° < FOV < 32.01°; 6.39 mm < IH < 9.23 mm.

[0096] 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. 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.

[0097] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better achieving the miniaturization of the lens. More specifically, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens of the present invention adopt spherical lenses.

[0098] 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.

[0099] Example 1

[0100] Please see Figure 1 The diagram shown is a schematic diagram of the structure of the optical lens provided in Embodiment 1 of the present invention. The optical lens includes, in sequence along the optical axis from the object side to the imaging plane: 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.

[0101] Among them, the first lens L1 has positive optical power, its object side S1 is convex, and its image side S2 is concave.

[0102] The second lens L2 has positive optical power, its object side S3 is concave, and its image side S4 is convex.

[0103] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is convex.

[0104] The fourth lens L4 has negative optical power, its object side S6 is concave, and its image side S7 is convex.

[0105] The third lens L3 and the fourth lens L4 form a cemented lens group with positive optical power, that is, the cemented surface of the image side of the third lens L3 and the object side of the fourth lens L4 is S6.

[0106] The fifth lens L5 has positive optical power, its object side S8 is convex, and its image side S9 is concave.

[0107] The sixth lens L6 has negative optical power, its object side S10 is concave, and its image side S11 is concave.

[0108] The object-side surface S12 and the image-side surface S13 of the filter G1 are both planar.

[0109] The object side S14 and image side S15 of the protective glass G2 are both flat.

[0110] The imaging plane S16 is a plane.

[0111] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are glass spherical lenses.

[0112] The relevant parameters of each lens in the optical lens of Example 1 are shown in Table 1-1.

[0113] Table 1-1

[0114]

[0115]

[0116] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 2 , Figure 3 As shown.

[0117] Figure 2 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 ±0.5%, indicating that the optical lens can effectively correct distortion.

[0118] 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 0.35 throughout the entire field of view. Within the range of 0–240 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.

[0119] Example 2

[0120] Please see Figure 4 The figure shows a schematic diagram of the optical lens provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side surface S9 of the fifth lens L5 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0121] The relevant parameters of each lens in the optical lens of Example 2 are shown in Table 2-1.

[0122] Table 2-1

[0123]

[0124]

[0125] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 5 , Figure 6 As shown.

[0126] from Figure 5 As can be seen, the distortion of the optical lens is controlled within ±2%, indicating that the optical lens can effectively correct distortion. From... Figure 6 As can be seen, the MTF value of this embodiment is above 0.2 throughout the entire field of view. In the range of 0 to 240 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.

[0127] Example 3

[0128] Please see Figure 7 The figure shows a schematic diagram of the optical lens 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 a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0129] The relevant parameters of each lens in the optical lens of Example 3 are shown in Table 3-1.

[0130] Table 3-1

[0131]

[0132]

[0133] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 8 , Figure 9 As shown.

[0134] from Figure 8 As can be seen, the distortion of the optical lens is controlled within ±1%, indicating that the optical lens can effectively correct distortion. From... Figure 9 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 240 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.

[0135] Example 4

[0136] Please see Figure 10The figure shows a schematic diagram of the optical lens provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side S8 of the fifth lens L5 is concave; the image side S9 of the fifth lens L5 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 of Example 4 are shown in Table 4-1.

[0138] Table 4-1

[0139]

[0140]

[0141] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 11 , Figure 12 As shown.

[0142] from Figure 11 As can be seen, the distortion of the optical lens is controlled within ±1.5%, indicating that the optical lens can effectively correct distortion. From... Figure 12 As can be seen, the MTF value of this embodiment is above 0.38 throughout the entire field of view. In the range of 0 to 240 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.

[0143] Example 5

[0144] Please see Figure 13 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 5 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the object side S8 of the fifth lens L5 is concave; the image side S9 of the fifth lens L5 is convex; the image side S11 of the sixth lens L6 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0145] The relevant parameters of each lens in the optical lens of Example 5 are shown in Table 5-1.

[0146] Table 5-1

[0147]

[0148]

[0149] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 14 , Figure 15 As shown.

[0150] from Figure 14 As can be seen, the distortion of the optical lens is controlled within ±1%, indicating that the optical lens can effectively correct distortion. From... Figure 15 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 240 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.

[0151] Example 6

[0152] Please see Figure 16 The figure shows a schematic diagram of the optical lens provided in Embodiment 6 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side surface S11 of the sixth lens L6 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0153] The relevant parameters of each lens in the optical lens of Example 6 are shown in Table 6-1.

[0154] Table 6-1

[0155]

[0156]

[0157] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 17 , Figure 18 As shown.

[0158] from Figure 17 As can be seen, the distortion of the optical lens is controlled within ±2%, indicating that the optical lens can effectively correct distortion. From... Figure 18 As can be seen, the MTF value of this embodiment is above 0.2 throughout the entire field of view. In the range of 0 to 240 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.

[0159] Example 7

[0160] Please see Figure 19 The figure shows a schematic diagram of the optical lens provided in Embodiment 7 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the fifth lens L5 has negative optical power; the image side surface S2 of the first lens L1 is convex; the image side surface S11 of the sixth lens L6 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0161] The relevant parameters of each lens in the optical lens of Example 7 are shown in Table 7-1.

[0162] Table 7-1

[0163]

[0164] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 20 , Figure 21 As shown.

[0165] from Figure 20 As can be seen, the distortion of the optical lens is controlled within ±1%, indicating that the optical lens can effectively correct distortion. From... Figure 21 As can be seen, the MTF value of this embodiment is above 0.2 throughout the entire field of view. In the range of 0 to 240 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.

[0166] Example 8

[0167] Please see Figure 22 The diagram shows a schematic of the optical lens provided in Embodiment 8 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the third lens L3 and the fourth lens L4 form a cemented lens group with negative optical power; the image-side surface S6 of the third lens L3 is concave; the object-side surface S6 of the fourth lens L4 is convex; the image-side surface S7 of the fourth lens L4 is concave; the image-side surface S11 of the sixth lens L6 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0168] The relevant parameters of each lens in the optical lens of Example 8 are shown in Table 8-1.

[0169] Table 8-1

[0170]

[0171]

[0172] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 23 , Figure 24 As shown.

[0173] from Figure 23 As can be seen, the distortion of the optical lens is controlled within ±2%, indicating that the optical lens can effectively correct distortion. From... Figure 24As can be seen, the MTF value of this embodiment is above 0.2 throughout the entire field of view. In the range of 0 to 240 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.

[0174] Example 9

[0175] Please see Figure 25 The diagram shows a schematic of the optical lens provided in Embodiment 9 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the third lens L3 and the fourth lens L4 form a cemented lens group with negative optical power; the image-side surface S6 of the third lens L3 is concave; the object-side surface S6 of the fourth lens L4 is convex; the image-side surface S7 of the fourth lens L4 is concave; the object-side surface S10 of the sixth lens L6 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0176] The relevant parameters of each lens in the optical lens of Example 9 are shown in Table 9-1.

[0177] Table 9-1

[0178]

[0179]

[0180] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 26 , Figure 27 As shown.

[0181] from Figure 26 As can be seen, the distortion of the optical lens is controlled within ±2%, indicating that the optical lens can effectively correct distortion. From... Figure 27 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 240 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.

[0182] Example 10

[0183] Please see Figure 28The diagram shows a schematic of the optical lens provided in Embodiment 10 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the third lens L3 and the fourth lens L4 form a cemented lens group with negative optical power; the image-side surface S2 of the first lens L1 is convex; the image-side surface S6 of the third lens L3 is concave; the object-side surface S6 of the fourth lens L4 is convex; the image-side surface S7 of the fourth lens L4 is concave; the object-side surface S10 of the sixth lens L6 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0184] The relevant parameters of each lens in the optical lens of Example 10 are shown in Table 10-1.

[0185] Table 10-1

[0186]

[0187]

[0188] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 29 , Figure 30 As shown.

[0189] from Figure 29 As can be seen, the distortion of the optical lens is controlled within ±1%, indicating that the optical lens can effectively correct distortion. From... Figure 30 As can be seen, the MTF value of this embodiment is above 0.2 throughout the entire field of view. In the range of 0 to 240 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.

[0190] Example 11

[0191] Please see Figure 31 The figure shows a schematic diagram of the optical lens provided in Embodiment 11 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side surface S2 of the first lens L1 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0192] The relevant parameters of each lens in the optical lens of Example 11 are shown in Table 11-1.

[0193] Table 11-1

[0194]

[0195]

[0196] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 32 , Figure 33 As shown.

[0197] from Figure 32 As can be seen, the distortion of the optical lens is controlled within ±2%, indicating that the optical lens can effectively correct distortion. From... Figure 33 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 240 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.

[0198] Please refer to Table 12 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, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0199] Table 12

[0200]

[0201]

[0202] 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 long focal length, large target surface, and high imaging quality.

[0203] 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.

[0204] 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 sequentially includes from the object side to the imaging surface along the optical axis: A first lens with positive optical power, whose object side is convex; A second lens with positive optical power, whose object side is concave and whose image side is convex; A third lens with positive optical power, whose object side is convex; A fourth lens with negative optical power; A fifth lens with optical power; A sixth lens with negative optical power; Wherein, the radius of curvature R4 of the image side of the second lens and the radius of curvature R5 of the object side of the third lens satisfy: |(R4 + R5) / (R4 - R5)| < 1.

2. The optical lens according to claim 1, characterized in that, The maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 10° < FOV / Fno < 18°; The total optical length TTL of the optical lens, the maximum field angle FOV of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 84 < 180°×TTL / IH / FOV < 135.

3. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.3 < f3 / f < 1.3; The effective focal length f of the optical lens and the radius of curvature R5 of the object side of the third lens satisfy: R5 / f > 0.

4.

4. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -5.6 < f4 / f < -0.5; 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: 0.3 < R7 / R8 < 8.

8.

5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: 1.3 < f12 / f < 5; The effective focal length f of the optical lens and the combined focal length f3456 of the third lens, the fourth lens, the fifth lens and the sixth lens satisfy: 1.3 < f3456 / f < 3.

6.

6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the radius of curvature R3 of the object side of the second lens satisfy: -1 < R3 / f < -0.4; The effective focal length f of the optical lens and the radius of curvature R4 of the image side of the second lens satisfy: -1.1 < R4 / f < -0.

5.

7. The optical lens according to claim 1, characterized in that, The radius of curvature R4 of the image side of the second lens and the radius of curvature R5 of the object side of the third lens satisfy: -2.1 < R4 / R5 < 0; The radius of curvature R3 of the object side of the second lens and the radius of curvature R5 of the object side of the third lens satisfy: -1.8 < R3 / R5 < 0.

8. The optical lens according to claim 1, characterized in that, The radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: -26.7 < (R3 + R4) / (R3 - R4) < -7.

9.

9. The optical lens according to claim 1, characterized in that, The radius of curvature R3 of the object side of the second lens and the radius of curvature R5 of the object side of the third lens satisfy: |(R3 + R5) / (R3 - R5)| < 1.

10. The optical lens according to claim 1, characterized in that, The sagittal height Sag3 of the object-side clear aperture of the second lens and the clear aperture diameter d3 of the object-side clear aperture of the second lens satisfy: -0.3 < Sag3 / d3 < -0.1; the sagittal height Sag4 of the image-side clear aperture of the second lens and the clear aperture diameter d4 of the image-side clear aperture of the second lens satisfy: -0.3 < Sag4 / d4 < -0.1; the sagittal height Sag5 of the object-side clear aperture of the third lens and the clear aperture diameter d5 of the object-side clear aperture of the third lens satisfy: d5 / Sag5 > 3.3.

Images