Optical lens

Abstract

The present invention provides an optical lens, which includes, from the object side to the imaging surface along the optical axis, a first lens with negative optical power, whose object side surface is convex and whose image side surface is concave; a second lens with optical power, whose object side surface is convex and whose image side surface is concave; a third lens with positive optical power, whose object side surface is concave and whose image side surface is convex; a fourth lens with negative optical power, whose object side surface is convex and whose image side surface is concave; a fifth lens with positive optical power, whose object side surface is convex and whose image side surface is convex; a sixth lens with optical power, whose object side surface is concave and whose image side surface is convex; a seventh lens with negative optical power, whose object side surface is convex and whose image side surface is concave near the optical axis. The optical lens of the present invention has one or more advantages such as a large field of view, large target surface imaging, and high imaging quality.

Description

Technical Field

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

[0002] With the rapid development of drones, security, automobiles and other fields, the pursuit of imaging effects of the lenses they carry has become more diversified. At present, drones are developing rapidly and have won the favor of consumers with their unique high-altitude perspective and wide-angle shooting images. Correspondingly, the demand for optical lenses that match them is also increasing. The optical lenses they carry require not only high-definition image quality, but also the ability to present larger local details, so as to achieve high-altitude vision and fully express local details, and shoot local close-up images.

[0003] However, how to better achieve the lens's large field of view, large target area imaging, and high imaging quality is still an issue that needs to be urgently addressed. Summary of the invention

[0004] In view of the above problems, an object of the present invention is to provide an optical lens having one or more advantages such as a large field of view, large target surface imaging, and high imaging quality.

[0005] The technical solution adopted by the present invention is:

[0006] An optical lens, comprising seven lenses, which include:

[0007] The first lens has a negative optical power, the object side surface of which is convex, and the image side surface of which is concave;

[0008] a second lens having optical power, whose object side surface is convex and whose image side surface is concave;

[0009] The third lens has positive power, its object side surface is concave and its image side surface is convex;

[0010] a fourth lens having negative optical power, whose object-side surface is convex and whose image-side surface is concave;

[0011] a fifth lens having positive refractive power, whose object-side surface is convex and whose image-side surface is convex;

[0012] a sixth lens having optical power, whose object side surface is concave and whose image side surface is convex;

[0013] The seventh lens element has a negative optical power, the object side surface of which is convex, and the image side surface of which is concave near the optical axis;

[0014] Among them, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.85 < TTL / IH < 1.1; the image-side curvature radius R4 of the second lens and the object-side curvature radius R5 of the third lens satisfy: 2.9 < (R4 - R5) / (R4 + R5) < 9.1.

[0015] Further preferably, the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4.9 < IH / EPD < 8.3.

[0016] Further preferably, the true image height IH corresponding to the maximum field of view angle of the optical lens, the maximum field of view angle FOV of the optical lens and the effective focal length f of the optical lens satisfy: 38° < (FOV × f) / IH < 62°.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.3 < f1 / f < -1.3; the object-side curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: 0.9 < R1 / f < 2.4.

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 2.5 < f3 / f < 9.9; the image-side curvature radius R4 of the second lens and the object-side curvature radius R5 of the third lens satisfy: -2.1 < R4 / R5 < -1.1.

[0019] Further preferably, the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -7.5 < f123 / f4567 < -2.2.

[0020] Further preferably, the focal length f2 of the second lens and the focal length f6 of the sixth lens satisfy: 3.9 < f2 / f6 < 12.5.

[0021] Further preferably, the image-side curvature radius R4 of the second lens and the effective focal length f of the optical lens satisfy: 1.3 < R4 / f < 1.9; the object-side curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: -1.4 < R5 / f < -0.8.

[0022] More preferably, the radius of curvature R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -1.4 < R11 / f < -0.5; the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -2.7 < R12 / f < -0.4.

[0023] More preferably, the sagittal height Sag4 of the image side light-passing semi-aperture of the second lens and the image side light-passing semi-aperture d4 of the second lens satisfy: 0.05 < Sag4 / d4 < 0.2; the sagittal height Sag5 of the object side light-passing semi-aperture of the third lens and the object side light-passing semi-aperture d5 of the third lens satisfy: -0.35 < Sag5 / d5 < -0.1.

[0024] Compared with the prior art, the optical lens provided by the present invention, through specific surface shape settings and reasonable optical power distribution, makes the structure of the optical lens relatively compact, effectively shortens the overall length of the optical lens, and at the same time has a large field of view angle and high imaging quality, can match a large target surface chip to achieve high-definition imaging. In addition, it can reasonably correct the overall aberration of the optical lens and improve the imaging quality of the optical lens. It better meets the use requirements of the drone for being thin and light, having high image quality, and wide-angle shooting. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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, in which:

[0026] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 2 is an astigmatism curve diagram of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 3 is an axial aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 4 is a lateral chromatic aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 5 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 6 is an astigmatism curve diagram of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 7 is an axial aberration curve diagram of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 8Graph showing the vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0034] Fig. 9 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0035] Fig.10 4 is an astigmatism curve diagram of the optical lens in Example 3 of the present invention.

[0036] Fig.11 Graph showing the axial aberration of the optical lens in Embodiment 3 of the present invention.

[0037] Fig.12 Graph showing the vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0038] Fig.13 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0039] Fig.14 4 is an astigmatism curve diagram of the optical lens in Example 4 of the present invention.

[0040] Fig.15 4 is an axial aberration curve diagram of the optical lens in Example 4 of the present invention.

[0041] Fig.16 Graph showing the vertical axis chromatic aberration of the optical lens in Example 4 of the present invention.

[0042] Fig.17 Schematic diagram of the structure of the optical lens in Example 5 of the present invention.

[0043] Fig.18 4 is an astigmatism curve diagram of the optical lens in Example 5 of the present invention.

[0044] Fig.19 Graph showing the axial aberration of the optical lens in Embodiment 5 of the present invention.

[0045] Fig. 20 Graph showing the vertical axis chromatic aberration of the optical lens in Example 5 of the present invention.

[0046] Fig.21 Schematic diagram of the structure of the optical lens in Example 6 of the present invention.

[0047] Fig. 22 4 is an astigmatism curve diagram of the optical lens in Example 6 of the present invention.

[0048] Fig.23 Graph showing the axial aberration of the optical lens in Embodiment 6 of the present invention.

[0049] Fig.24 Graph showing the vertical axis chromatic aberration of the optical lens in Example 6 of the present invention.

[0050] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0051] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application, and are not intended to limit the scope of the present 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.

[0052] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0053] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0054] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface 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 position of the concave surface 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 object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0055] It should also be understood that the terms "comprises", "including", "having", "includes" 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. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0056] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0057] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0058] The optical lens provided by the embodiment of the present invention comprises seven lenses in total, which include, in order from the object side to the imaging surface along the optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens.

[0059] In some embodiments, the first lens may have a negative optical power, with a convex object side and a concave image side. The second lens may have a positive optical power or a negative optical power, with a convex object side and a concave image side. The third lens may have a positive optical power, with a concave object side and a convex image side. The fourth lens may have a negative optical power, with a convex object side and a concave image side. The fifth lens may have a positive optical power, with a convex object side and a convex image side. The sixth lens may have a positive optical power or a negative optical power, with a concave object side and a convex image side. The seventh lens may have a negative optical power, with a convex object side and a concave image side at the near optical axis.

[0060] In some embodiments, the fourth lens and the fifth lens can be glued 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 difficulty of the processing technology of the optical lens and improving the assembly yield of the optical lens.

[0061] In some embodiments, the optical lens may further include an aperture, and the aperture may be located between the third lens and the fourth lens. It is understood that the aperture is used to limit the amount of light entering to change the brightness of the image. When the aperture is located between the third lens and the fourth lens, it is convenient to correct the aperture aberration.

[0062] In some embodiments, the optical lens may further include a filter, which may be disposed between the seventh lens and the imaging surface. The filter is used to filter out interference light to prevent the interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0063] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.85 < TTL / IH < 1.1. By reasonably restricting the ratio of the total length of the optical lens to the image height within the above range, it is ensured that the lens has a larger image plane under the condition of the same total length, achieving the balance between the miniaturization of the optical lens and the large image plane. More specifically, 0.97 < TTL / IH < 1.04.

[0064] In some embodiments, 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: 2.9 < (R4 - R5) / (R4 + R5) < 9.1. Satisfying the above range is beneficial to the smooth trend of light rays and reduces the aberration correction pressure of the rear lens of the optical lens. More specifically, 3.24 < (R4 - R5) / (R4 + R5) < 8.28.

[0065] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4.9 < IH / EPD < 8.3. Satisfying the above range enables the optical lens to satisfy the large image plane and large aperture while also ensuring sufficient image plane brightness in the edge field of view, preventing the occurrence of vignetting, thereby improving the imaging quality. More specifically, 5.55 < IH / EPD < 7.68.

[0066] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens, the maximum field of view angle FOV of the optical lens, and the effective focal length f of the optical lens satisfy: 38° < (FOV × f) / IH < 62°. By reasonably restricting the relationship between the focal length, field of view angle, and image height of the optical lens within the above range, it is beneficial to achieve the balance between the large field of view angle and large target plane imaging of the optical lens. More specifically, 42.86° < (FOV × f) / IH < 59.06°.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.3 < f1 / f < -1.3; the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.9 < R1 / f < 2.4. By setting the first lens to have a large negative refractive power and the surface shape of the object side surface of the first lens, it can ensure that the first lens accommodates a larger angle of light rays and collects as much light as possible into the rear optical system, achieving a large field of view while increasing the light flux and better realizing the large aperture performance of the lens. More specifically, -2.29 < f1 / f < -1.46; 1.07 < R1 / f < 2.21.

[0068] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 2.5 < f3 / f < 9.9; the image-side curvature radius R4 of the second lens and the object-side curvature radius R5 of the third lens satisfy: -2.1 < R4 / R5 < -1.1. Meeting the above ranges makes the light path more gentle and optimizes the aberration. More specifically, 2.76 < f3 / f < 9.16; -1.9 < R4 / R5 < -1.27.

[0069] In some embodiments, the combined focal length f123 of the first lens, the second lens, and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: -7.5 < f123 / f4567 < -2.2. Meeting the above ranges is conducive to the smooth transition of light by reasonably setting the relationship between the combined focal lengths of the lenses before and after the aperture, and at the same time corrects various aberrations of the optical lens and improves the imaging quality of the optical lens. More specifically, -6.92 < f123 / f4567 < -2.48.

[0070] In some embodiments, the focal length f2 of the second lens and the focal length f6 of the sixth lens satisfy: 3.9 < f2 / f6 < 12.5. Meeting the above ranges is conducive to the smooth transition of light by reasonably setting the focal length ratio of the second lens and the sixth lens in the lens, and at the same time corrects various aberrations of the optical lens and improves the imaging quality of the optical lens. More specifically, 4.37 < f2 / f6 < 11.34.

[0071] In some embodiments, the image-side curvature radius R4 of the second lens and the effective focal length f of the optical lens satisfy: 1.3 < R4 / f < 1.9; the object-side curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: -1.4 < R5 / f < -0.8. Meeting the above ranges limits the surface shapes of the image side of the second lens and the object side of the third lens, which is conducive to converging light while reducing the light deflection angle and making the light path transition smoothly, thereby improving the imaging quality of the optical lens. More specifically, 1.45 < R4 / f < 1.71; -1.26 < R5 / f < -0.87.

[0072] In some embodiments, the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.4 < R11 / f < -0.5; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: -2.7 < R12 / f < -0.4. Meeting the above ranges reasonably controls the surface shape of the sixth lens, which is conducive to increasing the field of view angle and the imaging area. More specifically, -1.21 < R11 / f < -0.61; -2.44 < R12 / f < -0.45.

[0073] In some embodiments, 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: 0.05 < Sag4 / d4 < 0.2; 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: -0.35 < Sag5 / d5 < -0.1. Meeting the above ranges can reduce the difficulty of aberration correction in the marginal field of view. More specifically, 0.09 < Sag4 / d4 < 0.17; -0.35 < Sag5 / d5 < -0.12.

[0074] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2 < TTL / f < 3. Meeting the above range can effectively limit the length of the lens, which is beneficial to the miniaturization of the optical lens. More specifically, 2.05 < TTL / f < 2.98.

[0075] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -3.3 < f4 / f < -1.8. Meeting the above conditions can endow the fourth lens with an appropriate negative optical power, which is beneficial to reducing the aberration generated by the front-end lens and at the same time reducing the difficulty of aberration correction of the rear-end lens. More specifically, -3.11 < f4 / f < -2.07.

[0076] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.4 < f5 / f < 0.9. Meeting the above conditions, by reasonably controlling the focal length of the fifth lens, it is beneficial to converge light while correcting the field curvature and distortion of the optical lens, and improving the imaging quality of the optical lens. More specifically, 0.53 < f5 / f < 0.87.

[0077] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -4.4 < f7 / f < -1.2. Meeting the above range can endow the seventh lens with an appropriate negative optical power, which is beneficial to balancing the astigmatism and field curvature of the optical lens and improving the imaging quality of the optical lens. More specifically, -4.09 < f7 / f < -1.38.

[0078] In some embodiments, the combined focal length f45 of the fourth lens and the fifth lens and the effective focal length f of the optical lens satisfy: 0.6 < f45 / f < 1.7. Meeting the above range, by reasonably controlling the focal length of the cemented lens of the fourth lens and the fifth lens, it is possible to effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, and balance the aberration of the optical lens, thereby improving the imaging quality of the optical lens. More specifically, 0.82 < f45 / f < 1.52.

[0079] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: 1.1 < R3 / f < 2.7. Meeting the above range and defining the surface shape of the object side surface of the second lens is beneficial to converging light while reducing the light deflection angle, enabling a smooth transition of the light trend and improving the imaging quality of the optical lens. More specifically, 1.34 < R3 / f < 2.46.

[0080] In some embodiments, the radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: R10 / f < -2.5; the sagittal height Sag10 of the image side clear aperture of the fifth lens and the image side clear aperture d10 of the fifth lens satisfy: -0.05 < Sag10 / d10 < 0. Meeting the above range and reasonably controlling the surface shape of the image side surface of the fifth lens helps to further optimize astigmatism and field curvature and reduce the difficulty of correcting higher-order aberrations of subsequent lenses. More specifically, -91.51 < R10 / f < -2.76; -0.041 < Sag10 / d10 < 0.

[0081] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the focal length f3 of the third lens satisfy: -0.5 < R5 / f3 < -0.05. Meeting the above range and controlling the radius of curvature of the object side surface of the third lens and the focal length of the third lens within a reasonable range can effectively correct aberrations, reduce chromatic aberration, and improve the imaging quality of the optical lens. More specifically, -0.46 < R5 / f3 < -0.09.

[0082] In some embodiments, 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: 0 < (R5 - R6) / (R5 + R6) < 0.4. Meeting the above range can effectively correct aberrations and improve the imaging quality of the optical lens. More specifically, 0.04 < (R5 - R6) / (R5 + R6) < 0.29.

[0083] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis and the overall optical length TTL of the optical lens satisfy: 0.45 < ∑CT / TTL < 0.65. Meeting the above range can effectively compress the overall length of the optical lens and is beneficial to the structural design and production process of the optical lens. More specifically, 0.51 < ∑CT / TTL < 0.61.

[0084] In some embodiments, 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 of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.25 < d1 / (IH / 2) / tan(FOV / 2) < 0.35. Meeting the above range can result in a small front aperture while satisfying the requirements of a large field of view angle and a large image plane for the optical lens. More specifically, 0.27 < d1 / (IH / 2) / tan(FOV / 2) < 0.31.

[0085] In some embodiments, the clear aperture semi-diameter d1 of the object side surface of the first lens and the clear aperture semi-diameter d6 of the image side surface of the third lens satisfy: 1.5 < d1 / d6 < 2.5; the clear aperture semi-diameter d7 of the object side surface of the fourth lens and the clear aperture semi-diameter d14 of the image side surface of the seventh lens satisfy: 0.15 < d7 / d14 < 0.35. Meeting the above range can limit the light path within a reasonable range by controlling the aperture ratio of the front and rear lenses, making the illuminance on the imaging plane uniform. More specifically, 1.72 < d1 / d6 < 2.23; 0.19 < d7 / d14 < 0.31.

[0086] In some embodiments, the optical lens satisfies the conditional formula: 3.4 mm < f < 5.8 mm, 110° < FOV < 136°, 1.3 mm < EPD < 2.2 mm, 9.9 mm < TTL < 12.6 mm, 2.4 < Fno < 2.8, 9.8 mm < IH < 12.2 mm, 35° < CRA < 45°, 1.1 mm < BFL < 2.3 mm, where 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 principal ray incident angle at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention has at least characteristics such as a small volume, a relatively large image plane, and a large field of view angle. More specifically, 3.76 mm < f < 5.34 mm, 122° < FOV < 126°, 1.41 mm < EPD < 2.02 mm, 10.97 mm < TTL < 11.51 mm, 2.6 < Fno < 2.7, 10.82 mm < IH < 11.24 mm, 37.42° < CRA < 43.91°, 1.12 mm < BFL < 2.09 mm.

[0087] 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 first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens in the optical lens provided by the present invention are all plastic lenses.

[0088] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens may be spherical lenses or aspherical lenses. Compared with spherical structures, aspherical structures can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and reducing the size of lenses, and better realizing miniaturization of lenses. More specifically, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens of the present invention may all be aspherical lenses, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and reducing the size of lenses, and better realizing miniaturization of lenses.

[0089] In various embodiments of the present invention, when the lens is an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0090] ;

[0091] Among them, 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 surface vertex, K is the quadratic surface coefficient, B, C, D, E, F, G, and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients respectively.

[0092] The present invention is further described below in multiple 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 table of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any other changes, substitutions, combinations or simplifications that do not deviate from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0093] Example 1

[0094] See also Figure 1, shown is a schematic diagram of the structure of the optical lens 100 provided in Example 1 of the present invention, and the optical lens 100 includes, from the object side to the imaging surface along the optical axis, a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7 and a filter G1.

[0095] The first lens L1 has negative refractive power, its object side surface S1 is convex, and its image side surface S2 is concave;

[0096] The second lens L2 has negative refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave;

[0097] The third lens L3 has positive refractive power, its object-side surface S5 is concave, and its image-side surface S6 is convex;

[0098] The fourth lens L4 has negative refractive power, its object-side surface S7 is convex, and its image-side surface S8 is concave;

[0099] The fifth lens L5 has positive refractive power, its object-side surface S8 is convex, and its image-side surface S9 is convex;

[0100] The fourth lens L4 and the fifth lens L5 form a cemented lens group with positive refractive power, that is, the cemented surface between the image side surface of the fourth lens L4 and the object side surface of the fifth lens L5 is S8;

[0101] The sixth lens L6 has negative refractive power, its object-side surface S10 is concave, and its image-side surface S11 is convex;

[0102] The seventh lens L7 has negative refractive power, its object-side surface S12 is convex, and its image-side surface S13 is concave at the near optical axis;

[0103] The object side surface S14 and the image side surface S15 of the filter G1 are both planes;

[0104] The imaging surface S16 is a plane.

[0105] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all plastic aspherical lenses.

[0106] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0107] Table 1-1

[0108]

[0109] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0110] Table 1-2

[0111]

[0112] In this embodiment, the astigmatism curve, the axial aberration curve, and the vertical chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 shown.

[0113] Figure 2 The astigmatism curve of Example 1 is shown, which represents the astigmatism of light of different wavelengths on the meridional image plane and the sagittal image plane, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the field angle (unit: °). It can be seen from the figure that the astigmatism of the meridional image plane and the sagittal image plane is controlled within ±0.1mm, indicating that the optical lens can correct the astigmatism well.

[0114] Figure 3 The axial aberration curve of Example 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane, the horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. It can be seen from the figure that the offset of the axial aberration is controlled within ±0.02mm, indicating that the optical lens can correct the axial aberration well.

[0115] Figure 4 The vertical chromatic aberration curve of Example 1 is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.555 μm) at different image heights on the imaging surface, the horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. It can be seen from the figure that the vertical chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±1 μm, indicating that the optical lens can perfectly correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image surface.

[0116] Example 2

[0117] See also Figure 5 , shown is a schematic diagram of the structure of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0118] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0119] Table 2-1

[0120]

[0121] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0122] Table 2-2

[0123]

[0124] In this embodiment, the astigmatism curve, the axial aberration curve, and the vertical axis chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 shown.

[0125] from Figure 6 It can be seen that the astigmatism of the meridian image plane and the sagittal image plane is controlled within ±0.1mm, indicating that the optical lens can correct the astigmatism well.

[0126] from Figure 7 It can be seen that the offset of axial aberration is controlled within ±0.02mm, which means that the optical lens can correct axial aberration well.

[0127] from Figure 8 It can be seen that the vertical chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±1μm, indicating that the optical lens can extremely well correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0128] Example 3

[0129] See also Fig. 9 , shown is a schematic diagram of the structure of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0130] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0131] Table 3-1

[0132]

[0133] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0134] Table 3-2

[0135]

[0136] In this embodiment, the astigmatism curve, the axial aberration curve, and the vertical axis chromatic aberration curve of the optical lens 300 are respectively as follows: Fig.10 , Fig.11 , Fig.12 shown.

[0137] from Fig.10It can be seen that the astigmatism of the meridian image plane and the sagittal image plane is controlled within ±0.1mm, indicating that the optical lens can correct the astigmatism well.

[0138] from Fig.11 It can be seen that the offset of axial aberration is controlled within ±0.02mm, which means that the optical lens can correct axial aberration well.

[0139] from Fig.12 It can be seen that the vertical chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±1μm, indicating that the optical lens can extremely well correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0140] Example 4

[0141] See also Fig.13 , which is a schematic diagram of the structure of an optical lens 400 provided in Example 4 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the second lens L2 has positive focal power; the sixth lens L6 has positive focal power; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0142] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0143] Table 4-1

[0144]

[0145] The surface parameters of the aspherical lens of the optical lens in Example 4 are shown in Table 4-2.

[0146] Table 4-2

[0147]

[0148] In this embodiment, the astigmatism curve, the axial aberration curve, and the vertical chromatic aberration curve of the optical lens 400 are respectively as follows: Fig.14 , Fig.15 , Fig.16 shown.

[0149] from Fig.14 It can be seen that the astigmatism of the meridian image plane and the sagittal image plane is controlled within ±0.1mm, indicating that the optical lens can correct the astigmatism well.

[0150] from Fig.15 It can be seen that the offset of axial aberration is controlled within ±0.03mm, which means that the optical lens can correct axial aberration well.

[0151] from Fig.16It can be seen that the vertical chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2μm, indicating that the optical lens can extremely well correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0152] Example 5

[0153] See also Fig.17 , which is a schematic diagram of the structure of an optical lens 500 provided in Example 5 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the second lens L2 has positive focal power; the sixth lens L6 has positive focal power; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0154] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0155] Table 5-1

[0156]

[0157] The surface parameters of the aspheric lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0158] Table 5-2

[0159]

[0160] In this embodiment, the astigmatism curve, the axial aberration curve, and the vertical chromatic aberration curve of the optical lens 500 are respectively as follows: Fig.18 , Fig.19 , Fig. 20 shown.

[0161] from Fig.18 It can be seen that the astigmatism of the meridian image plane and the sagittal image plane is controlled within ±0.1mm, indicating that the optical lens can correct the astigmatism well.

[0162] from Fig.19 It can be seen that the offset of axial aberration is controlled within ±0.04mm, which means that the optical lens can correct axial aberration well.

[0163] from Fig. 20 It can be seen that the vertical chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2μm, indicating that the optical lens can extremely well correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0164] Example 6

[0165] See also Fig.21, which is a schematic diagram of the structure of an optical lens 600 provided in Example 6 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the second lens L2 has positive focal power; the sixth lens L6 has positive focal power; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0166] The relevant parameters of each lens in the optical lens 600 in Example 6 are shown in Table 6-1.

[0167] Table 6-1

[0168]

[0169] The surface parameters of the aspheric lens of the optical lens 600 in Example 6 are shown in Table 6-2.

[0170] Table 6-2

[0171]

[0172] In this embodiment, the astigmatism curve, the axial aberration curve, and the vertical chromatic aberration curve of the optical lens 500 are respectively as follows: Fig. 22 , Fig.23 , Fig.24 shown.

[0173] from Fig. 22 It can be seen that the astigmatism of the meridian image plane and the sagittal image plane is controlled within ±0.15mm, indicating that the optical lens can correct the astigmatism well.

[0174] from Fig.23 It can be seen that the offset of axial aberration is controlled within ±0.04mm, which means that the optical lens can correct axial aberration well.

[0175] from Fig.24 It can be seen that the vertical chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2μm, indicating that the optical lens can extremely well correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0176] Please refer to Table 7, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the chief ray incident angle CRA at the maximum image height, the maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0177] Table 7

[0178]

[0179]

[0180] In summary of the above embodiments, the optical lens provided by the present invention has a relatively compact structure through a specific surface shape setting and a reasonable distribution of optical power, effectively shortens the overall length of the optical lens, and has a larger field of view and higher imaging quality, and can match a large target chip to achieve high-definition imaging. In addition, it can also reasonably correct the overall aberration of the optical lens and improve the imaging quality of the optical lens. It better meets the use requirements of drones for thinness, high image quality, and wide-angle shooting.

[0181] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0182] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical lens, comprising seven 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 convex and whose image side is concave; A second lens with an optical power, whose object side is convex and whose image side is concave; A third lens with a positive optical power, whose object side is concave and whose image side is convex; A fourth lens with a negative optical power, whose object side is convex and whose image side is concave; A fifth lens with a positive optical power, whose object side is convex and whose image side is convex; A sixth lens with an optical power, whose object side is concave and whose image side is convex; A seventh lens with a negative optical power, whose object side is convex and whose image side is concave near the optical axis; Wherein, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.85 < TTL / IH < 1.1; The curvature radius R4 of the image side of the second lens and the curvature radius R5 of the object side of the third lens satisfy: 2.9 < (R4 - R5) / (R4 + R5) < 9.1; The combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -7.5 < f123 / f4567 < -2.

2.

2. The optical lens according to claim 1, characterized in that: The true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4.9 < IH / EPD < 8.

3.

3. The optical lens according to claim 1, characterized in that: The true image height IH corresponding to the maximum field of view angle of the optical lens, the maximum field of view angle FOV of the optical lens and the effective focal length f of the optical lens satisfy: 38° < (FOV × f) / IH < 62°.

4. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.3 < f1 / f < -1.3; The curvature radius R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: 0.9 < R1 / f < 2.

4.

5. 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: 2.5 < f3 / f < 9.9; The curvature radius R4 of the image side of the second lens and the curvature radius R5 of the object side of the third lens satisfy: -2.1 < R4 / R5 < -1.

1.

6. The optical lens according to claim 1, characterized in that: The clear aperture radius d1 of the object side of the first lens and the clear aperture radius d6 of the image side of the third lens satisfy: 1.5 < d1 / d6 < 2.5; The clear aperture radius d7 of the object side of the fourth lens and the clear aperture radius d14 of the image side of the seventh lens satisfy: 0.15 < d7 / d14 < 0.

35.

7. The optical lens according to claim 1, characterized in that: The focal length f2 of the second lens and the focal length f6 of the sixth lens satisfy: 3.9 < f2 / f6 < 12.

5.

8. The optical lens according to claim 1, characterized in that: The curvature radius R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: 1.3 < R4 / f < 1.9; The curvature radius R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: -1.4 < R5 / f < -0.

8.

9. The optical lens according to claim 1, characterized in that: The radius of curvature R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -1.4 < R11 / f < -0.5; the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -2.7 < R12 / f < -0.

4.

10. The optical lens according to claim 1, characterized in that: The sagittal height Sag4 of the image side clear aperture of the second lens and the image side clear aperture d4 of the second lens satisfy: 0.05 < Sag4 / d4 < 0.2; the sagittal height Sag5 of the object side clear aperture of the third lens and the object side clear aperture d5 of the third lens satisfy: -0.35 < Sag5 / d5 < -0.1.

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