Optical lens

Abstract

The invention provides an optical lens, which comprises seven lenses from an object side to an imaging surface along an optical axis: a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; the third lens has positive focal power, the object side surface of the third lens near the optical axis is a convex surface, and the image side surface of the third lens is a convex surface; the fourth lens has negative focal power, the object side surface of the fourth lens is a convex surface near the optical axis, and the image side surface of the fourth lens is a concave surface near the optical axis; the fifth lens has positive focal power, the object side surface of the fifth lens is a convex surface near the optical axis, and the image side surface of the fifth lens is a convex surface; the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a convex surface; and the object side surface of the seventh lens is a convex surface near the optical axis, and the image side surface of the seventh lens is a concave surface near the optical axis. The optical lens provided by the invention has one or more advantages of ultra-wide angle, large image plane, large aperture and the like.

Description

Technical Field

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

[0002] As a special optical lens, an ultra-wide-angle lens can capture a large range of images. However, this large viewing angle also brings obvious barrel distortion. Scenes that should be horizontal or vertical at the edge of the image will appear bent and deformed, and only the scenes in the central area remain relatively unchanged. In addition, the ultra-wide-angle lens also has other deficiencies: easy attenuation of the edge image quality, great difficulty in aberration correction, large distortion, etc. Despite these problems, through advanced optical design and post-processing algorithm correction, the ultra-wide-angle lens is still widely used in fields such as scene monitoring, satellite positioning, robot navigation, micro intelligent systems, and engineering surveying, providing panoramic vision solutions for multiple industries and helping to achieve efficient and accurate monitoring and positioning. Summary of the Invention

[0003] Aiming at 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: An optical lens, comprising a total of seven lenses, which are sequentially arranged from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, the object side surface of which is convex near the optical axis, and the image side surface is concave; A second lens with a positive optical power, the object side surface of which is concave, and the image side surface is convex; A third lens with a positive optical power, the object side surface of which is convex near the optical axis, and the image side surface is convex; A fourth lens with a negative optical power, the object side surface of which is convex near the optical axis, and the image side surface is concave near the optical axis; A fifth lens with a positive optical power, the object side surface of which is convex near the optical axis, and the image side surface is convex; A sixth lens with a negative optical power, the object side surface of which is concave, and the image side surface is convex; A seventh lens with a negative optical power, the object side surface of which is convex near the optical axis, and the image side surface is concave near the optical axis; Wherein, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 90° < FOV / Fno < 125°; the true image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens, and the radian value θ of the maximum half field of view of the optical lens satisfy: 0.96 < (IH / 2) / (f×θ) < 1.22.

[0005] More preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6 < TTL / f < 9; 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: 1.8 < TTL / IH < 2.4.

[0006] More preferably, 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: 3.3 < IH / f < 4.5; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 1 < BFL / f < 1.22.

[0007] More preferably, the clear aperture radius d1 of the object side 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: 1.21 < d1 / (IH / 2) / tan(FOV / 4) < 1.59; the combined focal length f34567 of the third, fourth, fifth, sixth and seventh lenses and the effective focal length f of the optical lens satisfy: 1.6 < f34567 / f < 2.4.

[0008] More preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.3 < f1 / f < -2.6; the curvature radius R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: 3.3 < R1 / f < 4.5; the curvature radius R2 of the image side of the first lens and the effective focal length f of the optical lens satisfy: 0.9 < R2 / f < 1.1.

[0009] More preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 4.5 < f2 / f < 6.7; the curvature radius R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: -8.5 < R3 / f < -4.2; the curvature radius R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: -2.9 < R4 / f < -2.

[0010] More preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 4.5 < f3 / f < 7; the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -9 < f4 / f < -5.5; the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < f5 / f < 1.

[0011] Further preferably, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -2.4 < f6 / f < -1.5; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: -0.55 < R11 / f < -0.4; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.2 < R12 / f < -0.8.

[0012] Further preferably, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -15 < f7 / f < -3.7; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.8 < R13 / f < 1.2; the image-side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.5 < R14 / f < 0.9.

[0013] Further preferably, the object-side curvature radius R3 of the second lens and the image-side curvature radius R4 of the second lens satisfy: 0.3 < (R3 - R4) / (R3 + R4) < 0.6; the object-side curvature radius R11 of the sixth lens and the image-side curvature radius R12 of the sixth lens satisfy: -3.6 < (R11 + R12) / (R11 - R12) < -2.3.

[0014] The optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and enable the lens to have one or more advantages such as ultra-wide angle, large image plane, and large aperture. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where: Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0016] Figure 2 is an F-Theta distortion curve graph of the optical lens in Embodiment 1 of the present invention.

[0017] Figure 3 is an MTF curve graph of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 4 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0019] Figure 5 is an F-Theta distortion curve graph of the optical lens in Embodiment 2 of the present invention.

[0020] Figure 6 This is the MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0021] Figure 7 This is the structural schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0022] Figure 8 This is the F-Theta distortion curve graph of the optical lens in Embodiment 3 of the present invention.

[0023] Figure 9 This is the MTF curve graph of the optical lens in Embodiment 3 of the present invention.

[0024] Figure 10 This is the structural schematic diagram of the optical lens in Embodiment 4 of the present invention.

[0025] Figure 11 This is the F-Theta distortion curve graph of the optical lens in Embodiment 4 of the present invention.

[0026] Figure 12 This is the MTF curve graph of the optical lens in Embodiment 4 of the present invention.

[0027] Figure 13 This is the structural schematic diagram of the optical lens in Embodiment 5 of the present invention.

[0028] Figure 14 This is the F-Theta distortion curve graph of the optical lens in Embodiment 5 of the present invention.

[0029] Figure 15 This is the MTF curve graph of the optical lens in Embodiment 5 of the present invention.

[0030] Figure 16 This is the structural schematic diagram of the optical lens in Embodiment 6 of the present invention.

[0031] Figure 17 This is the F-Theta distortion curve graph of the optical lens in Embodiment 6 of the present invention.

[0032] Figure 18 This is the MTF curve graph of the optical lens in Embodiment 6 of the present invention.

[0033] Figure 19 This is the structural schematic diagram of the optical lens in Embodiment 7 of the present invention.

[0034] Figure 20 This is the F-Theta distortion curve graph of the optical lens in Embodiment 7 of the present invention.

[0035] Figure 21 This is the MTF curve graph of the optical lens in Embodiment 7 of the present invention.

[0036] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0037] For a better understanding of the present application, more detailed descriptions of various aspects of the present application will be made 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 do not 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.

[0038] It should be noted that in this specification, the expressions such as 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 teachings of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0039] In the drawings, for ease of illustration, the thickness, dimensions, and shape of the lens have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are for illustrative purposes only and are not drawn to an exact scale.

[0040] In this document, 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 being photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

[0041] It should also be understood that the terms “comprises,” “comprising,” “has,” “including,” and / or “including having,” when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. In addition, when an expression such as “at least one of...” appears after a list of listed features, it modifies the entire list of listed features rather than an individual element in the list. In addition, when describing the embodiments of the present application, the use of “may” means “one or more embodiments of the present application.” And the term “exemplary” is intended to refer to an example or illustration.

[0042] Unless otherwise defined, all terms (including technical and scientific terms) used herein shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in a common dictionary) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0043] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will describe this application in detail with reference to the drawings and in combination with the embodiments.

[0044] The optical lens provided by the embodiment of the present invention includes seven lenses, which are, 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.

[0045] In some embodiments, the first lens may have a negative optical power, its object side surface may be convex near the optical axis, and its image side surface may be concave. The second lens may have a positive optical power, its object side surface may be concave, and its image side surface may be convex. The third lens may have a positive optical power, its object side surface may be convex near the optical axis, and its image side surface may be convex. The fourth lens may have a negative optical power, its object side surface may be convex near the optical axis, and its image side surface may be concave near the optical axis. The fifth lens may have a positive optical power, its object side surface may be convex near the optical axis, and its image side surface may be convex. The sixth lens may have a negative optical power, its object side surface may be concave, and its image side surface may be convex. The seventh lens may have a negative optical power, its object side surface may be convex near the optical axis, and its image side surface may be concave near the optical axis.

[0046] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the second lens and the third lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the image. When the diaphragm is located between the second lens and the third lens, it is convenient for correcting the diaphragm aberration.

[0047] In some embodiments, the optical lens may further include a filter, and the filter is disposed 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 normal imaging.

[0048] In some embodiments, the fifth lens and the sixth 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.

[0049] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 90° < FOV / Fno < 125°; the true image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens, and the radian value θ of the maximum half field of view of the optical lens satisfy: 0.96 < (IH / 2) / (f×θ) < 1.22. By satisfying the above ranges and reasonably limiting the ratio of the maximum field of view to the aperture value, it is possible to collect light at large angles and obtain good imaging quality. At the same time, it is possible to control the optical lens to have small distortion and improve the imaging quality of the optical lens. More specifically: 96.89° < FOV / Fno < 116.76°.

[0050] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6 < TTL / f < 9; the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 1.8 < TTL / IH < 2.4. By satisfying the above ranges, the length of the lens can be effectively limited, and the miniaturization of the lens can be achieved. At the same time, with the same overall length of the lens ensured, it has a larger image plane, can match a larger-sized imaging chip to achieve high-definition imaging, and can better achieve the balance between the small overall length and the large image plane of the lens. More specifically: 6.43 < TTL / f < 8.92; 1.88 < TTL / IH < 2.22.

[0051] In some embodiments, the true image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 3.3 < IH / f < 4.5; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 1 < BFL / f < 1.22. By satisfying the above ranges and reasonably controlling the ratio of the image height to the focal length of the optical lens, it helps the optical lens to have the characteristic of a large image plane, improves the resolution of the lens, and further improves the imaging quality. At the same time, by limiting the optical lens to have an appropriate back focus, it is convenient to reasonably arrange the positions of the lenses, reduces the processing and assembly difficulty, is beneficial to reducing the interference between different components, and improves the yield. More specifically: 3.38 < IH / f < 4.12.

[0052] 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: 1.21 < d1 / (IH / 2) / tan(FOV / 4) < 1.59; the combined focal length f34567 of the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens and the effective focal length f of the optical lens satisfy: 1.6 < f34567 / f < 2.4. Satisfying the above ranges can reasonably arrange the overall geometry of the optical lens and improve its structural stability. At the same time, reasonably limiting the proportion of the optical power of the rear diaphragm lens group is beneficial to correcting the chromatic aberration and field curvature of the optical system, as well as reducing the light deflection angle, reducing sensitivity, and reducing the lens forming difficulty. More specifically: 1.75 < f34567 / f < 2.2.

[0053] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.3 < f1 / f < -2.6; the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: 3.3 < R1 / f < 4.5; the curvature radius R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.9 < R2 / f < 1.1. Satisfying the above ranges, by reasonably limiting the proportion of the optical power of the first lens and its surface shape, it is beneficial to collect the marginal field of view light into the rear system as much as possible, realize the collection of large-angle light, and thus realize the ultra-wide-angle imaging of the lens. More specifically: -3.07 < f1 / f < -2.7; 3.61 < R1 / f < 4.09; 0.98 < R2 / f < 1.08.

[0054] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 4.5 < f2 / f < 6.7; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -8.5 < R3 / f < -4.2; the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: -2.9 < R4 / f < -2. Satisfying the above ranges, by reasonably limiting the proportion of the optical power of the second lens and its surface shape, it is beneficial to improve the field curvature and can further improve the imaging quality of the optical lens. More specifically: 4.9 < f2 / f < 6.13; -7.87 < R3 / f < -4.63; -2.64 < R4 / f < -2.15.

[0055] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 4.5 < f3 / f < 7; the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -9 < f4 / f < -5.5; the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < f5 / f < 1. Meeting the above ranges, respectively limiting the appropriate proportion of the optical power of the third lens, the fourth lens, and the fifth lens can effectively correct the aberration generated at the front end of the lens and improve the imaging quality of the lens. More specifically: 4.87 < f3 / f < 6.45; -8.52 < f4 / f < -5.95; 0.79 < f5 / f < 0.94.

[0056] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -2.4 < f6 / f < -1.5; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: -0.55 < R11 / f < -0.4; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.2 < R12 / f < -0.8. Meeting the above ranges, by reasonably limiting the proportion of the optical power of the sixth lens and its surface shape, it is beneficial to reduce the difficulty of correcting aberration and distortion and improve the overall imaging quality. More specifically: -2.27 < f6 / f < -1.66; -0.52 < R11 / f < -0.44; -1.1 < R12 / f < -0.81.

[0057] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -15 < f7 / f < -3.7; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.8 < R13 / f < 1.2; the image-side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.5 < R14 / f < 0.9. Meeting the above ranges, by reasonably limiting the proportion of the optical power of the seventh lens and its surface shape, it is beneficial to increase the divergence degree of light, increase the area of light entering the imaging surface, and achieve large target surface imaging. More specifically: -13.77 < f7 / f < -3.79; 0.85 < R13 / f < 1.09; 0.55 < R14 / f < 0.82.

[0058] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: 0.3 < (R3 - R4) / (R3 + R4) < 0.6; the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: -3.6 < (R11 + R12) / (R11 - R12) < -2.3. Satisfying the above ranges can control the second lens and the sixth lens to have appropriate surface shapes, which is beneficial to reducing the difficulty of aberration and distortion correction and improving the overall imaging quality. More specifically: 0.34 < (R3 - R4) / (R3 + R4) < 0.51; -3.38 < (R11 + R12) / (R11 - R12) < -2.54.

[0059] 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 < IH / EPD < 8.5. Satisfying the above range can increase the width of the light beam incident on the optical lens, improve the relative illuminance, and avoid vignetting. More specifically: 6.07 < IH / EPD < 8.23.

[0060] In some embodiments, the sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis respectively and the total optical length TTL of the optical lens satisfy: 0.6 < ΣCT / TTL < 0.67. Satisfying the above range can control the total optical length of the optical lens and the sum of the central thicknesses of each lens within a reasonable range, which helps to achieve high pixel characteristics and improve the imaging quality of the optical lens.

[0061] In some embodiments, the sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis respectively and the effective focal length f of the optical lens satisfy: 4.04 < ΣCT / f < 5.49. Satisfying the above range can control the effective focal length of the optical lens and the sum of the central thicknesses of each lens within a reasonable range, making the lens more compact.

[0062] In some embodiments, the combined focal length f56 of the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 1.3 < f56 / f < 2.3. Satisfying the above range, by reasonably limiting the proportion of the optical power of the cemented lens composed of the fifth lens and the sixth lens, it is beneficial to reducing chromatic aberration and spherical aberration and improving the imaging quality. More specifically: 1.45 < f56 / f < 2.11.

[0063] In some embodiments, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 1.5 < (R1 + R2) / (R1 - R2) < 2. Meeting the above range and controlling the first lens to have an appropriate surface shape is conducive to collecting as much marginal field light as possible into the rear system, achieving large-angle light collection, and thus realizing the ultra-wide-angle imaging of the lens. More specifically: 1.64 < (R1 + R2) / (R1 - R2) < 1.81.

[0064] In some embodiments, the optical lens satisfies the following conditional expressions: 1.5 mm < f < 1.9 mm; 180° < FOV < 220°; 0.7 mm < EPD < 1.1 mm; 11 mm < TTL < 15 mm; 1.6 < Fno < 2.1; 6 mm < IH < 6.5 mm; 27° < CRA < 34°; 1.8 mm < BFL < 2 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 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 range, the optical lens has at least one or more advantages such as ultra-wide angle, large image plane, and large aperture. More specifically: 1.54 mm < f < 1.87 mm; 193° < FOV < 201°; 0.76 mm < EPD < 1.05 mm; 11.99 mm < TTL < 14.01 mm; 1.65 < Fno < 2.01; 6.31 mm < IH < 6.38 mm; 27.88° < CRA < 33.81°; 1.86 mm < BFL < 1.91 mm.

[0065] 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. More specifically, the optical lens provided by the present invention can adopt an all-plastic lens structure, which not only enables the lens to have excellent imaging performance, but also makes the structure of the lens relatively compact, and can better achieve the balance of miniaturization and high image quality of the lens.

[0066] 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 the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. 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 can all be aspherical lenses.

[0067] 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 equation: ; where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and B, C, D, E, and F are the coefficients of the fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order curved surfaces, respectively.

[0068] The present invention will be further described below with multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are slightly different. For specific differences, please refer to the parameter tables of each embodiment. The following embodiments are only the preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any other changes, substitutions, combinations, or simplifications made without departing 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.

[0069] Embodiment 1 Please refer to Figure 1 , which shows a schematic structural diagram of an optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 sequentially includes, along the optical axis from the object side to the imaging surface: a first lens L1, a second lens L2, a diaphragm ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and a filter G1.

[0070] Among them, the first lens L1 has a negative optical power. Its object side surface S1 is convex near the optical axis, and its image side surface S2 is concave; The second lens L2 has a positive optical power. Its object side surface S3 is concave, and its image side surface S4 is convex; The third lens L3 has a positive optical power. Its object side surface S5 is convex near the optical axis, and its image side surface S6 is convex; The fourth lens L4 has a negative optical power. Its object side surface S7 is convex near the optical axis, and its image side surface S8 is concave near the optical axis; The fifth lens L5 has a positive focal power. Its object side S9 is convex near the optical axis, and its image side S10 is convex. The sixth lens L6 has a negative focal power. Its object side S10 is concave, and its image side S11 is convex. The fifth lens L5 and the sixth lens L6 form a cemented lens group, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens L6 is S10. The seventh lens L7 has a negative focal power. Its object side S12 is convex near the optical axis, and its image side S13 is concave near the optical axis. Both the object side S14 and the image side S15 of the filter G1 are flat surfaces. The imaging surface S16 is a flat surface.

[0071] 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 made of plastic aspherical lenses.

[0072] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0073] Table 1-1 The surface type parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0074] Table 1-2 In this embodiment, the F-Theta distortion curve graph and the MTF curve graph of the optical lens 100 are respectively as Figure 2 , Figure 3 shown.

[0075] Figure 2 The F-Theta distortion curve graph in this embodiment is shown, which represents the distortion of different field angles on the imaging surface. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the semi-field angle (unit: °). It can be seen from the figure that the distortion value is controlled within 0% - 40%, indicating that the optical lens 100 can correct distortion.

[0076] Figure 3The MTF (Modulation Transfer Function) curve graph of Embodiment 1 is shown, which represents the modulation of lens imaging at different spatial frequencies for each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF value of this embodiment is above 0.4 within the entire field of view. In the range of 0 - 90 lp / mm, the MTF curve decreases uniformly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0077] Embodiment 2 Please refer to Figure 4 , which shows the structural schematic diagram of the optical lens 200 provided in Embodiment 2 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0078] The relevant parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0079] Table 2-1 The surface shape parameters of the aspherical lens of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0080] Table 2-2 In this embodiment, the F-Theta distortion curve graph and the MTF curve graph of the optical lens 200 are respectively as shown in Figure 5 , Figure 6 shown. It can be seen from Figure 5 that the distortion value is controlled within 0% - 30%, indicating that the optical lens 200 can correct distortion. It can be seen from Figure 6 that the MTF value of this embodiment is above 0.3 within the entire field of view. In the range of 0 - 90 lp / mm, the MTF curve decreases uniformly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0081] Embodiment 3 Please refer to Figure 7 , which shows the structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0082] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0083] Table 3-1 The surface shape parameters of the aspherical lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0084] Table 3-2 In this embodiment, the F-Theta distortion curve graph and the MTF curve graph of the optical lens 300 are respectively as Figure 8 、 Figure 9 shown. It can be seen from Figure 8 that the distortion value is controlled within 0% to 35%, indicating that the optical lens 300 can correct distortion. It can be seen from Figure 9 that the MTF value of this embodiment is above 0.4 in the entire field of view. In the range of 0 to 90 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0085] Embodiment 4 Please refer to Figure 10 , which shows the structural schematic diagram of the optical lens 400 provided in Embodiment 4 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0086] The relevant parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0087] Table 4-1 The surface shape parameters of the aspherical lens of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0088] Table 4-2 In this embodiment, the F-Theta distortion curve graph and the MTF curve graph of the optical lens 400 are respectively as Figure 11 、 Figure 12 shown. It can be seen from Figure 11 that the distortion value is controlled within -10% to 20%, indicating that the optical lens 400 can correct distortion. It can be seen from Figure 12 that the MTF value of this embodiment is above 0.5 in the entire field of view. In the range of 0 to 90 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0089] Embodiment 5 Please refer to Figure 13, which shows the structural schematic diagram of the optical lens 500 provided in Embodiment 5 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0090] The relevant parameters of each lens in the optical lens 500 in Embodiment 5 are shown in Table 5-1.

[0091] Table 5-1 The aspherical lens surface type parameters of the optical lens 500 in Embodiment 5 are shown in Table 5-2.

[0092] Table 5-2 In this embodiment, the F-Theta distortion curve graph and MTF curve graph of the optical lens 500 are respectively as shown in Figure 14 , Figure 15 shown. It can be seen from Figure 14 that the distortion value is controlled within 0% to 45%, indicating that the optical lens 500 can correct distortion. It can be seen from Figure 15 that the MTF value of this embodiment is above 0.6 within the entire field of view. In the range of 0 to 90 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0093] Embodiment 6 Please refer to Figure 16 , which shows the structural schematic diagram of the optical lens 600 provided in Embodiment 6 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0094] The relevant parameters of each lens in the optical lens 600 in Embodiment 6 are shown in Table 6-1.

[0095] Table 6-1 The aspherical lens surface type parameters of the optical lens 600 in Embodiment 6 are shown in Table 6-2.

[0096] Table 6-2 In this embodiment, the F-Theta distortion curve graph and MTF curve graph of the optical lens 600 are respectively as shown in Figure 17 , Figure 18 shown. It can be seen from Figure 17It can be seen that the distortion value is controlled within 0% to 30%, indicating that the optical lens 600 can correct distortion. From Figure 18 It can be seen that the MTF value of this embodiment is above 0.5 within the entire field of view. In the range of 0 to 90 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0097] Embodiment 7 Please refer to Figure 19 , which shows a schematic structural diagram of the optical lens 700 provided in Embodiment 7 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0098] The relevant parameters of each lens in the optical lens 700 in Embodiment 7 are shown in Table 7-1.

[0099] Table 7-1 The surface type parameters of the aspherical lens of the optical lens 700 in Embodiment 7 are shown in Table 7-2.

[0100] Table 7-2 In this embodiment, the F-Theta distortion curve graph and MTF curve graph of the optical lens 700 are respectively as shown in Figure 20 , Figure 21 shown. From Figure 20 it can be seen that the distortion value is controlled within 0% to 40%, indicating that the optical lens 700 can correct distortion. From Figure 21 it can be seen that the MTF value of this embodiment is above 0.4 within the entire field of view. In the range of 0 to 90 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0101] Please refer to Table 8-1 and Table 8-2 for the optical characteristics corresponding to the above embodiments, including the effective focal length f, optical total length TTL, aperture value Fno, chief ray angle of incidence CRA at the maximum image height, true image height IH corresponding to the maximum field of view angle, maximum field of view angle FOV, entrance pupil diameter EPD, back focal length BFL of the optical lens, and the values corresponding to each conditional formula in each embodiment.

[0102] Table 8-1 Table 8-2 In combination with the above embodiments, the optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and endow the lens with one or more advantages such as ultra-wide angle, large image plane, and large aperture.

[0103] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0104] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these 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 appended claims.

Claims

1. An optical lens, consisting of seven lenses in total, characterized in that, From the object side to the imaging surface along the optical axis, it successively includes: A first lens with a negative optical power, whose object side is convex near the optical axis and whose image side is concave; A second lens with a positive optical power, whose object side is concave and whose image side is convex; A third lens with a positive optical power, whose object side is convex near the optical axis and whose image side is convex; A fourth lens with a negative optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; A fifth lens with a positive optical power, whose object side is convex near the optical axis and whose image side is convex; A sixth lens with a negative 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 near the optical axis and whose image side is concave 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: 90° < FOV / Fno < 125°; the true image height IH corresponding to the maximum field of view angle of the optical lens, the effective focal length f of the optical lens and the radian value θ of the maximum half field of view angle of the optical lens satisfy: 0.96 < (IH / 2) / (f×θ) < 1.

22.

2. The optical lens according to claim 1, wherein The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6 < TTL / f < 9; 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: 1.8 < TTL / IH < 2.

4.

3. The optical lens according to claim 1, wherein 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: 3.3 < IH / f < 4.5; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 1 < BFL / f < 1.

22.

4. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter d1 of the object side of the first lens, the true image height IH corresponding to the maximum field of view angle of the optical lens and the maximum field of view angle FOV of the optical lens satisfy: 1.21 < d1 / (IH / 2) / tan(FOV / 4) < 1.59; the combined focal length f34567 of the third, fourth, fifth, sixth and seventh lenses and the effective focal length f of the optical lens satisfy: 1.6 < f34567 / f < 2.

4.

5. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.3 < f1 / f < -2.6; the curvature radius R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: 3.3 < R1 / f < 4.5; the curvature radius R2 of the image side of the first lens and the effective focal length f of the optical lens satisfy: 0.9 < R2 / f < 1.

1.

6. The optical lens according to claim 1, wherein The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 4.5 < f2 / f < 6.7; the curvature radius R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: -8.5 < R3 / f < -4.2; the curvature radius R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: -2.9 < R4 / f < -2.

7. The optical lens according to claim 1, wherein The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 4.5 < f3 / f < 7; the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -9 < f4 / f < -5.5; the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < f5 / f < 1.

8. The optical lens according to claim 1, wherein The focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -2.4 < f6 / f < -1.5; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: -0.55 < R11 / f < -0.4; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.2 < R12 / f < -0.

8.

9. The optical lens according to claim 1, wherein, The focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -15 < f7 / f < -3.7; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.8 < R13 / f < 1.2; the image-side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.5 < R14 / f < 0.

9.

10. The optical lens according to claim 1, characterized in that, The object-side curvature radius R3 of the second lens and the image-side curvature radius R4 of the second lens satisfy: 0.3 < (R3 - R4) / (R3 + R4) < 0.6; the object-side curvature radius R11 of the sixth lens and the image-side curvature radius R12 of the sixth lens satisfy: -3.6 < (R11 + R12) / (R11 - R12) < -2.3.

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