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 negative optical power, whose object side surface is concave and whose image side surface is convex; a third lens with negative optical power, which is a meniscus lens; a fourth lens with positive optical power, whose object side surface is convex and whose image side surface is convex; a fifth lens with negative optical power, whose object side surface is concave and whose image side surface is convex; a sixth lens with negative optical power, whose image side surface is concave at the near optical axis; and a seventh lens with positive optical power, whose object side surface is convex at the near optical axis. The optical lens provided by the present invention uses seven lenses with specific optical power and specific surface shape, so that the lens has one or more advantages such as ultra-large viewing angle, large aperture, 48M high-pixel imaging, and short total length.

Description

Technical Field

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

[0002] With the improvement of people's living standards and the upgrading of aesthetic concepts, drone photography, as a novel and unique shooting method, has been loved by more and more people. Whether it is wedding photography, real estate advertising, tourism promotional videos or film and television production, drone photography can provide unique perspectives and shocking visual effects, and the market demand continues to grow. At present, the drone camera lenses on the market have the problem that they cannot simultaneously meet the advantages of high pixel, ultra-large imaging angle of view, large aperture and short total length. Summary of the Invention

[0003] In view of the above problems, the purpose of the present invention is to provide an optical lens with excellent imaging quality.

[0004] The technical solution adopted by the present invention is as follows:

[0005] An optical lens is composed of seven lenses with optical power, and sequentially includes from the object side to the imaging surface along the optical axis:

[0006] A first lens with negative optical power, whose object side is convex and whose image side is concave;

[0007] A second lens with negative optical power, whose object side is concave and whose image side is convex;

[0008] A third lens with negative optical power, and the third lens is a meniscus lens;

[0009] A fourth lens with positive optical power, whose object side is convex and whose image side is convex;

[0010] A fifth lens with negative optical power, whose object side is concave and whose image side is convex;

[0011] A sixth lens with negative optical power, whose image side is concave near the optical axis;

[0012] A seventh lens with positive optical power, whose object side is convex near the optical axis;

[0013] Wherein, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 79° < FOV / Fno < 90°; the curvature radius R3 of the object side of the second lens and the curvature radius R4 of the image side of the second lens satisfy: -0.8 < (R3 - R4) / (R3 + R4) < 0.

[0014] 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: 6.3 < IH / EPD < 7.7; the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.7 < IH / f < 3.3.

[0015] Further preferably, the effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens, and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 55° < (f × FOV) / IH < 65°; the true image height IH corresponding to the maximum field of view angle of the optical lens and the back focal length BFL of the optical lens satisfy: 4.9 < IH / BFL < 6.3.

[0016] Further preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -55 < f2 / f < -10; 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.

[0017] Further preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -88 < f3 / f < -40; the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: 0.8 < R5 / R6 < 1.6.

[0018] Further preferably, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -3.6 < f6 / f < -1; the curvature radius R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 0.85 < R12 / f < 1.9.

[0019] Further preferably, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.3 < f7 / f < 4; 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: -1.7 < f123 / f4567 < -1.1.

[0020] Further preferably, the focal length f6 of the sixth lens and the focal length f7 of the seventh lens satisfy: -1 < f6 / f7 < -0.7; the curvature radius R11 of the object side surface of the sixth lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: 0.6 < R11 / R14 < 1.1.

[0021] Further preferably, the radius of curvature R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: -1.3 < R4 / f < -0.7; the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 0.85 < R7 / f < 1.

[0022] Further preferably, the radius of curvature R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -2.7 < R9 / f < -0.7; 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: -9.4 < R10 / f < -0.9.

[0023] Further preferably, 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: -0.5 < (R5 - R6) / (R5 + R6) < 0.6; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: -1 < (R9 - R10) / (R9 + R10) < 0; 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: -0.2 < (R3 - R4) / (R3 + R4) < 0.

[0024] Compared with the prior art, the optical lens provided by the present invention has one or more advantages such as an ultra-large viewing angle, a large aperture, 48M high-pixel imaging, and a short overall length through specific surface shape settings and reasonable optical power distribution. In addition, by using a combination of glass and plastic lenses, the cost can be effectively reduced and the thermal stability can be improved. 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 the field curvature curve graph of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 3 is the F-Theta distortion curve graph of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 4 is the axial aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 5 is the lateral chromatic aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 6 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0032] Figure 7 4 is a field curvature curve diagram of the optical lens in Example 2 of the present invention.

[0033] Figure 8 Graph showing the F-Theta distortion of the optical lens in Embodiment 2 of the present invention.

[0034] Fig. 9 Graph showing the axial aberration of the optical lens in Embodiment 2 of the present invention.

[0035] Fig.10 Graph showing the vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0036] Fig.11 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0037] Fig.12 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0038] Fig.13 Graph showing the F-Theta distortion of the optical lens in Embodiment 3 of the present invention.

[0039] Fig.14 Graph showing the axial aberration of the optical lens in Embodiment 3 of the present invention.

[0040] Fig.15 Graph showing the vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0041] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] The optical lens provided by the embodiment of the present invention is composed of seven lenses with optical focal length, which include: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens in sequence from the object side to the imaging surface along the optical axis.

[0050] In some embodiments, the first lens may have a negative optical power, its object side may be convex, and its image side may be concave. The second lens may have a negative optical power, its object side may be concave, and its image side may be convex. The third lens may have a negative optical power, and the third lens is a meniscus lens, its object side may be concave or convex near the optical axis, and its image side may be convex or concave near the optical axis. The fourth lens may have a positive optical power, its object side may be convex, and its image side may be convex. The fifth lens may have a negative optical power, its object side may be concave, and its image side may be convex. The sixth lens may have a negative optical power, its object side may be concave or convex near the optical axis, and its image side may be concave near the optical axis. The seventh lens may have a positive optical power, its object side may be convex near the optical axis, and its image side may be convex or concave near the optical axis.

[0051] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the third lens and the fourth lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the imaging. When the diaphragm is located between the third lens and the fourth lens, it is convenient for correcting the diaphragm aberration.

[0052] In some embodiments, the optical lens may further include a filter, and the filter is disposed along the optical axis between the seventh lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting the normal imaging.

[0053] In some embodiments, the sixth lens and the seventh 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.

[0054] In some embodiments, the maximum field of view FOV of the optical lens and the f-number Fno of the optical lens satisfy: 79° < FOV / Fno < 90°; 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: -0.8 < (R3 - R4) / (R3 + R4) < 0. Satisfying the above ranges defines that the optical lens has a suitable field of view and f-number, can collect light at large angles and obtain good imaging quality. And by reasonably defining the shapes of the object side and the image side of the second lens, it is possible to control the second lens to have an appropriate surface shape and effectively correct the aberration of the optical lens. More specifically: 79.9° < FOV / Fno < 82.2°; -0.2 < (R3 - R4) / (R3 + R4) < 0. Further, -0.13 < (R3 - R4) / (R3 + R4) < -0.04.

[0055] 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: 6.3 < IH / EPD < 7.7; the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.7 < IH / f < 3.3. Satisfying the above ranges, by controlling the image height and the entrance pupil diameter within appropriate ranges, it helps to increase the width of the light beam entering the optical lens and improve the image plane brightness. Moreover, by reasonably controlling the ratio of the image height to the focal length of the optical lens, both the ultra-wide-angle characteristic can be achieved to meet the shooting requirements of a large wide angle, and the large image plane characteristic can be achieved to improve the imaging quality of the optical lens. More specifically: 6.89 < IH / EPD < 7.05; 3 < IH / f < 3.08.

[0056] In some embodiments, the effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens, and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 55° < (f × FOV) / IH < 65°; the true image height IH corresponding to the maximum field of view angle of the optical lens and the back focal length BFL of the optical lens satisfy: 4.9 < IH / BFL < 6.3. Satisfying the above ranges, by reasonably restricting the relationship between the focal length, the field of view angle, and the image height of the optical lens, it is beneficial to achieve the balance between the large field of view angle and the large target surface imaging of the optical lens. At the same time, reasonably restricting the ratio of the image height to the back focal length can endow the optical lens with the large target surface characteristic and can match a large-size chip. More specifically: 60.57° < (f × FOV) / IH < 61.24°; 5.39 < IH / BFL < 5.74.

[0057] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -55 < f2 / f < -10; 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. Satisfying the above ranges, by reasonably defining the focal length ratio of the second lens and the surface type of the second lens, it can effectively reduce the difficulty of subsequent lens aberration correction. More specifically: -50.39 < f2 / f < -10.93; 0.78 < R3 / R4 < 0.92.

[0058] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -88 < f3 / f < -40; the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: 0.8 < R5 / R6 < 1.6. Satisfying the above ranges, by reasonably defining the focal length ratio of the third lens and the surface type of the third lens, it helps to distribute the optical power and improve the imaging quality of the optical lens. More specifically: -79.98 < f3 / f < -44.95; 0.86 < R5 / R6 < 1.46.

[0059] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -3.6 < f6 / f < -1; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: 0.85 < R12 / f < 1.9. Satisfying the above ranges can endow the sixth lens with an appropriate negative optical power and define the surface shape of the image side of the sixth lens, which can effectively balance the lens aberration and improve the imaging quality. More specifically: -3.33 < f6 / f < -1.08; 0.94 < R12 / f < 1.7.

[0060] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.3 < f7 / f < 4; the combined focal length f123 of the first, second, and third lenses and the combined focal length f4567 of the fourth, fifth, sixth, and seventh lenses satisfy: -1.7 < f123 / f4567 < -1.1. Satisfying the above ranges and reasonably defining the ratio of the focal length of the seventh lens to the focal length of the optical lens is beneficial to adjusting the angle of incidence of the marginal field light on the imaging surface and increasing the imaging range. At the same time, defining the ratio of the focal lengths of the lens groups before and after the aperture of the optical lens can effectively correct the aberration generated by the lens groups before and after the aperture and improve the imaging quality of the optical lens. More specifically: 1.43 < f7 / f < 3.6; -1.51 < f123 / f4567 < -1.23.

[0061] In some embodiments, the focal length f6 of the sixth lens and the focal length f7 of the seventh lens satisfy: -1 < f6 / f7 < -0.7; the object-side curvature radius R11 of the sixth lens and the image-side curvature radius R14 of the seventh lens satisfy: 0.6 < R11 / R14 < 1.1. Satisfying the above ranges, by reasonably setting the focal lengths and surface shapes of the doublet lens, on the one hand, it is beneficial to eliminating the geometric aberration of the imaging system and improving the lens imaging quality. On the other hand, it is beneficial to reducing the risk of stray light between the sixth lens and the seventh lens and improving the imaging picture quality. More specifically: -0.95 < f6 / f7 < -0.75; 0.66 < R11 / R14 < 1.01.

[0062] 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 < -0.7; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.85 < R7 / f < 1. Satisfying the above ranges, by reasonably setting the surface shapes of the second lens and the fourth lens, the spherical aberration can be further optimized. More specifically: -1.19 < R4 / f < -0.82; 0.88 < R7 / f < 0.92.

[0063] In some embodiments, the radius of curvature R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -2.7 < R9 / f < -0.7; 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: -9.4 < R10 / f < -0.9. Satisfying the above ranges and reasonably setting the surface shape of the fifth lens helps to further balance the aberration of the lens and improve the imaging quality. More specifically: -2.48 < R9 / f < -0.8; -8.57 < R10 / f < -1.01.

[0064] 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: -0.5 < (R5 - R6) / (R5 + R6) < 0.6; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: -1 < (R9 - R10) / (R9 + R10) < 0. Satisfying the above ranges and controlling the shapes of the object side surface and the image side surface of the third lens and the fifth lens can control the third lens and the fifth lens to have appropriate surface shapes, effectively improve the field curvature and aberration, and improve the imaging quality. More specifically: -0.08 < (R5 - R6) / (R5 + R6) < 0.2; -0.56 < (R9 - R10) / (R9 + R10) < -0.05.

[0065] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 3.5 < TTL / f < 4.4. Satisfying the above range can effectively limit the length of the lens and is beneficial to achieving the characteristic of a short overall length. More specifically: 3.83 < TTL / f < 3.98.

[0066] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 1.1 < TTL / IH < 1.5. Satisfying the above range is beneficial to achieving a reasonable balance between the overall length of the lens and the large image plane. More specifically: 1.24 < TTL / IH < 1.32.

[0067] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.45 < BFL / f < 0.65. Satisfying the above range is beneficial to reducing the volume of the optical lens, and is beneficial to reducing the interference between the lens and the imaging chip and improving the assembly yield. More specifically: 0.52 < BFL / f < 0.58.

[0068] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -1.8 < f1 / f < -1.3. Meeting the above range and controlling the first lens to have an appropriate negative optical power helps to control distortion and reduce field curvature, thereby improving the geometric accuracy of the imaging surface. More specifically: -1.67 < f1 / f < -1.39.

[0069] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.8 < f4 / f < 1. Meeting the above range and controlling the fourth lens to have an appropriate positive optical power can converge light, reduce the light deflection angle, and improve the imaging quality. More specifically: 0.89 < f4 / f < 0.92.

[0070] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -45 < f5 / f < -2.8. Meeting the above range and controlling the fifth lens to have an appropriate negative optical power helps to increase the imaging area and improve the imaging quality. More specifically: -41.31 < f5 / f < -3.09.

[0071] In some embodiments, the combined focal length f67 of the sixth lens and the seventh lens and the effective focal length f of the optical lens satisfy: -37.9 < f67 / f < -7.3. Meeting the above range is beneficial for the chief ray to emerge parallel onto the imaging surface, and further beneficial for achieving a smaller chief ray incident angle. More specifically: -34.54 < f67 / f < -8.12.

[0072] In some embodiments, the curvature radius R5 of the object side surface of the third lens, the central thickness CT3 of the third lens, and the curvature radius R6 of the image side surface of the third lens satisfy: 0.6 < (R5 + CT3) / R6 < 1.6. Meeting the above range and reasonably adjusting the surface shape of the third lens can make the surface shape of the third lens close to a concentric circle shape, which is beneficial for reducing the optical path difference between the center and the periphery of the lens, and thus beneficial for correcting the distortion of the lens. More specifically: 0.65 < (R5 + CT3) / R6 < 1.48.

[0073] In some embodiments, the sagittal height Sag9 of the clear aperture of the object side surface of the fifth lens and the clear aperture d9 of the object side surface of the fifth lens satisfy: -0.5 < Sag9 / d9 < -0.2. Meeting the above range is beneficial for reducing the influence of the spherical aberration of the fifth lens itself on the imaging quality of the optical lens. More specifically: -0.35 < Sag9 / d9 < -0.26.

[0074] In some embodiments, the sagittal height Sag10 of the image side clear aperture of the fifth lens and the clear aperture diameter d10 of the image side clear aperture of the fifth lens satisfy: -0.3 < Sag10 / d10 < 0. Meeting the above range is beneficial to reducing the scattering of light and improving the transmittance and imaging quality of the optical lens. More specifically: -0.22 < Sag10 / d10 < -0.1.

[0075] In some embodiments, the optical lens satisfies the following conditional expressions: 2.4 mm < f < 3 mm; 1 mm < EPD < 1.3 mm; 9 mm < TTL < 12 mm; 2.1 < Fno < 2.5; 1.2 mm < BFL < 1.7 mm; 170° < FOV < 200°; 7.5 mm < IH < 9 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 overall optical length of the optical lens, Fno represents the f-number of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above range, the optical lens has at least one or more advantages such as an ultra-large viewing angle, a large aperture, 48M high-pixel imaging, and a short overall length. More specifically: 2.66 mm < f < 2.71 mm; 1.15 mm < EPD < 1.19 mm; 10.21 mm < TTL < 10.66 mm; 2.26 < Fno < 2.31; 1.41 mm < BFL < 1.53 mm; 183° < FOV < 189°; 8.12 mm < IH < 8.19 mm.

[0076] 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. On the other hand, 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 adopts a mixed structure of seven lenses with glass and plastic, which can better achieve high-definition imaging. Specifically, the first lens and the fourth lens can be made of glass lenses, and the second lens, the third lens, the fifth lens, the sixth lens, and the seventh lens are all made of plastic lenses. Adopting the glass-plastic hybrid structure can effectively reduce costs, improve thermal stability, reduce volume, and provide an optical lens product with higher cost performance.

[0077] 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 and the fourth lens of the present invention may both be spherical lenses, and the second lens, the third lens, the fifth lens, the sixth lens, and the seventh lens may both be aspherical lenses.

[0078] 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:

[0079] ;

[0080] 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, and G are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, and fourteenth-order surface coefficients respectively.

[0081] 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.

[0082] Example 1

[0083] 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.

[0084] The first lens L1 has negative refractive power, its object side surface S1 is convex, and its image side surface S2 is concave;

[0085] The second lens L2 has negative refractive power, its object side surface S3 is concave, and its image side surface S4 is convex;

[0086] The third lens L3 has negative refractive power, an object-side surface S5 thereof is concave at the near optical axis, and an image-side surface S6 thereof is convex at the near optical axis;

[0087] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is convex;

[0088] The fifth lens L5 has negative refractive power, its object-side surface S9 is concave, and its image-side surface S10 is convex;

[0089] The sixth lens L6 has negative refractive power, an object-side surface S11 thereof is concave at the near optical axis, and an image-side surface S12 thereof is concave at the near optical axis;

[0090] The seventh lens L7 has positive refractive power, an object-side surface S12 thereof is convex at the near optical axis, and an image-side surface S13 thereof is convex at the near optical axis;

[0091] The sixth lens L6 and the seventh lens L7 form a cemented lens group with negative refractive power, that is, the cemented surface between the image side surface of the sixth lens L6 and the object side surface of the seventh lens L7 is S12;

[0092] The object side surface S14 and the image side surface S15 of the filter G1 are both planes;

[0093] The imaging surface S16 is a plane.

[0094] The first lens L1 and the fourth lens L4 are glass spherical lenses, and the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are plastic aspherical lenses.

[0095] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0096] Table 1-1

[0097]

[0098] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0099] Table 1-2

[0100]

[0101] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and vertical axis chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 shown.

[0102] Figure 2The field curvature curve of Example 1 is shown, which indicates the degree of curvature of light of different wavelengths on the meridional image plane and the sagittal image plane, with the horizontal axis indicating the offset (unit: mm) and the vertical axis indicating the half field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.1 mm, indicating that the optical lens can correct the field curvature well.

[0103] Figure 3 The F-Theta distortion curve of Example 1 is shown, which represents the F-Theta distortion at different image heights on the imaging plane, the horizontal axis represents the F-Theta distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the F-Theta distortion of the optical lens 100 is controlled within -6% to 8%, indicating that the distortion of the optical lens 100 is well corrected.

[0104] Figure 4 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 ±0.04mm, indicating that the optical lens can correct the axial aberration well.

[0105] Figure 5 The vertical chromatic aberration curve of Example 1 is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.55 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 -4 μm~6 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.

[0106] Example 2

[0107] See also Figure 6 , which is a schematic diagram of the structure of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the object side surface S11 of the sixth lens L6 is a convex surface at the near optical axis; the image side surface S13 of the seventh lens L7 is a concave surface at the near optical axis; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0108] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0109] Table 2-1

[0110]

[0111] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0112] Table 2-2

[0113]

[0114] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Fig. 9 , Fig.10 shown.

[0115] from Figure 7 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within -0.1mm~0.05mm, indicating that the optical lens 200 can correct the field curvature well.

[0116] from Figure 8 It can be seen that the F-Theta distortion of the optical lens 200 is controlled within ±8%, indicating that the distortion of the optical lens 200 is well corrected.

[0117] from Fig. 9 It can be seen that the offset of the axial aberration is controlled within -0.08mm~0.04mm, which means that the optical lens 200 can correct the axial aberration well.

[0118] from Fig.10 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±7μm, indicating that the optical lens 200 can extremely well correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0119] Example 3

[0120] See also Fig.11 , 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 differences of this embodiment are: the object-side surface S5 of the third lens L3 is convex at the near optical axis; the image-side surface S6 of the third lens L3 is concave at the near optical axis; the object-side surface S11 of the sixth lens L6 is convex at the near optical axis; the image-side surface S13 of the seventh lens L7 is concave at the near optical axis; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0121] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0122] Table 3-1

[0123]

[0124] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0125] Table 3-2

[0126]

[0127] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens 300 are respectively as follows: Fig.12 , Fig.13 , Fig.14 , Fig.15 shown.

[0128] from Fig.12 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.05mm, indicating that the optical lens 300 can correct the field curvature well.

[0129] from Fig.13 It can be seen that the F-Theta distortion of the optical lens 300 is controlled within -8%~6%, indicating that the distortion of the optical lens 300 is well corrected.

[0130] from Fig.14 It can be seen that the offset of the axial aberration is controlled within -0.03mm~0.04mm, which means that the optical lens 300 can correct the axial aberration well.

[0131] from Fig.15 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±7μm, indicating that the optical lens 300 can extremely well correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0132] Please refer to Table 4-1 and Table 4-2, which are the optical characteristics corresponding to the above-mentioned embodiments, including the effective focal length f of the optical lens, the maximum field of view FOV, the entrance pupil diameter EPD, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view, the back focal length BFL and the numerical value corresponding to each conditional expression in each embodiment.

[0133] Table 4-1

[0134]

[0135] Table 4-2

[0136]

[0137] In summary of the above embodiments, the optical lens provided by the present invention adopts seven lenses with specific optical focal lengths and specific surface shapes, so that the lens has one or more advantages such as ultra-large viewing angle, large aperture, 48M high-pixel imaging, and short total length.

[0138] 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.

[0139] 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 is composed of seven lenses with optical power, and successively includes from the object side to the imaging surface along the optical axis: A first lens with negative optical power, whose object side is convex and whose image side is concave; A second lens with negative optical power, whose object side is concave and whose image side is convex; A third lens with negative optical power, and the third lens is a meniscus lens; A fourth lens with positive optical power, whose object side is convex and whose image side is convex; A fifth lens with negative optical power, whose object side is concave and whose image side is convex; A sixth lens with negative optical power, whose image side is concave near the optical axis; A seventh lens with positive optical power, whose object side is convex near the optical axis; Wherein, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 79° < FOV / Fno < 90°; the curvature radius R3 of the object side of the second lens and the curvature radius R4 of the image side of the second lens satisfy: -0.8 < (R3 - R4) / (R3 + R4) < 0.

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: 6.3 < IH / EPD < 7.7; the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.7 < IH / f < 3.

3.

3. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 55° < (f × FOV) / IH < 65°; the true image height IH corresponding to the maximum field of view angle of the optical lens and the back focal length BFL of the optical lens satisfy: 4.9 < IH / BFL < 6.

3.

4. The optical lens according to claim 1, characterized in that: The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -55 < f2 / f < -10; the curvature radius R3 of the object side of the second lens and the curvature radius R4 of the image side of the second lens satisfy: 0.7 < R3 / R4 < 1.

5. The optical lens according to claim 1, characterized in that: The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -88 < f3 / f < -40; the curvature radius R5 of the object side of the third lens and the curvature radius R6 of the image side of the third lens satisfy: 0.8 < R5 / R6 < 1.

6.

6. The optical lens according to claim 1, characterized in that: The focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -3.6 < f6 / f < -1; the curvature radius R12 of the image side of the sixth lens and the effective focal length f of the optical lens satisfy: 0.85 < R12 / f < 1.

9.

7. The optical lens according to claim 1, characterized in that: The focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.3 < f7 / f < 4; 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: -1.7 < f123 / f4567 < -1.

1.

8. The optical lens according to claim 1, characterized in that: The focal length f6 of the sixth lens and the focal length f7 of the seventh lens satisfy: -1 < f6 / f7 < -0.7; the object-side curvature radius R11 of the sixth lens and the image-side curvature radius R14 of the seventh lens satisfy: 0.6 < R11 / R14 < 1.

1.

9. The optical lens according to claim 1, characterized in that: 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 < -0.7; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.85 < R7 / f < 1.

10. The optical lens according to claim 1, characterized in that: The object-side curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: -2.7 < R9 / f < -0.7; the image-side curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: -9.4 < R10 / f < -0.

9.

11. The optical lens according to claim 1, characterized in that: The object-side curvature radius R5 of the third lens and the image-side curvature radius R6 of the third lens satisfy: -0.5 < (R5 - R6) / (R5 + R6) < 0.6; the object-side curvature radius R9 of the fifth lens and the image-side curvature radius R10 of the fifth lens satisfy: -1 < (R9 - R10) / (R9 + R10) < 0; the object-side curvature radius R3 of the second lens and the image-side curvature radius R4 of the second lens satisfy: -0.2 < (R3 - R4) / (R3 + R4) < 0.

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