Optical lens

Abstract

The present invention provides an optical lens having seven lenses, which include, in order from the object side to the image side along the optical axis: a first lens having negative optical power, whose object side surface is convex at the near optical axis and whose image side surface is concave; a second lens having positive optical power, whose object side surface is concave and whose image side surface is convex; a third lens having positive optical power, whose object side surface is convex at the near optical axis and whose image side surface is convex; a fourth lens having negative optical power, whose object side surface is convex at the near optical axis and whose image side surface is concave at the near optical axis; a fifth lens having positive optical power, whose object side surface is convex at the near optical axis and whose image side surface is convex; a sixth lens having negative optical power, whose object side surface is concave and whose image side surface is convex; and a seventh lens having negative optical power, whose object side surface is convex at the near optical axis and whose image side surface is concave at the near optical axis. The optical lens provided by the present invention has one or more advantages, such as ultra-wide angle, large image surface, and large aperture.

Description

Technical Field

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

[0002] As a special optical lens, the ultra-wide-angle lens is able to capture a wide range of images. However, this wide viewing angle also brings about obvious barrel distortion, where objects at the edges of the image that should be horizontal or vertical will appear curved and deformed, leaving only the center area relatively unchanged. In addition, ultra-wide-angle lenses have other shortcomings: image quality at the edges is easily degraded, aberration correction is difficult, and distortion is large. Despite these problems, ultra-wide-angle lenses are still widely used in scene monitoring, satellite positioning, robot navigation, micro-intelligent systems, and engineering measurement due to their unique advantages through advanced optical design and post-processing algorithm correction. They provide panoramic vision solutions for multiple industries, helping to achieve efficient and accurate monitoring and positioning. Summary of the Invention

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

[0004] The technical solution adopted in the present invention is:

[0005] An optical lens, comprising seven lenses, including the following elements in order from the object side to the imaging surface along the optical axis:

[0006] The first lens has a negative optical power, the object side surface of which is convex near the optical axis and the image side surface of which is concave;

[0007] a second lens having positive refractive power, whose object-side surface is concave and whose image-side surface is convex;

[0008] The third lens has positive refractive power, its object-side surface is convex near the optical axis, and its image-side surface is convex;

[0009] a fourth lens element having negative optical power, whose object-side surface is convex near the optical axis and whose image-side surface is concave near the optical axis;

[0010] The fifth lens element has positive refractive power, its object-side surface is convex near the optical axis, and its image-side surface is convex;

[0011] a sixth lens element having negative optical power, whose object-side surface is concave and whose image-side surface is convex;

[0012] The seventh lens element has a negative optical power, the object-side surface of which is convex near the optical axis, and the image-side surface of which is concave near the optical axis;

[0013] Among them, 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.

[0014] Further preferably, 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.

[0015] Further 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.

[0016] Further preferably, the clear aperture radius 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.

[0017] Further 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 radius of curvature 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 radius of curvature 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.

[0018] Further 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 radius of curvature 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 radius of curvature 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.

[0019] Further 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] The optical lens provided by the present invention uses seven lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, enabling the lens to have one or more advantages such as ultra-wide angle, large image plane, and large aperture. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, where:

[0025] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0026] Figure 2 is the F-Theta distortion curve diagram of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 3 This is the MTF curve of the optical lens in Example 1 of the present invention.

[0028] Figure 4 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0029] Figure 5 Graph showing the F-Theta distortion of the optical lens in Example 2 of the present invention.

[0030] Figure 6 This is an MTF curve diagram of the optical lens in Example 2 of the present invention.

[0031] Figure 7 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0032] Figure 8 Graph showing the F-Theta distortion of the optical lens in Example 3 of the present invention.

[0033] Figure 9 This is the MTF curve of the optical lens in Example 3 of the present invention.

[0034] Figure 10 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0035] Figure 11 Graph showing the F-Theta distortion of the optical lens in Example 4 of the present invention.

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

[0037] Figure 13 Schematic diagram of the structure of the optical lens in Example 5 of the present invention.

[0038] Figure 14 Graph showing the F-Theta distortion of the optical lens in Example 5 of the present invention.

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

[0040] Figure 16 Schematic diagram of the structure of the optical lens in Example 6 of the present invention.

[0041] Figure 17 Graph showing the F-Theta distortion of the optical lens in Example 6 of the present invention.

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

[0043] Figure 19Schematic diagram of the structure of the optical lens in Example 7 of the present invention.

[0044] Figure 20 Graph showing the F-Theta distortion of the optical lens in Example 7 of the present invention.

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

[0046] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0047] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of 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.

[0048] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of the present invention.

[0049] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0050] In this article, the paraxial region refers to the area near the optical axis. If a lens surface is convex and the location of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the location of the concave surface is undefined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0051] 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 preclude 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 list of 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.

[0052] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0053] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this 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.

[0054] The optical lens provided by an embodiment of the present invention includes seven lenses, which are, along the optical axis, from the object side to the imaging surface, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

[0055] In some embodiments, the first lens may have negative optical power, the object-side surface thereof may be convex at the near optical axis, and the image-side surface thereof may be concave. The second lens may have positive optical power, the object-side surface thereof may be concave, and the image-side surface thereof may be convex. The third lens may have positive optical power, the object-side surface thereof may be convex at the near optical axis, and the image-side surface thereof may be convex. The fourth lens may have negative optical power, the object-side surface thereof may be convex at the near optical axis, and the image-side surface thereof may be concave at the near optical axis. The fifth lens may have positive optical power, the object-side surface thereof may be convex at the near optical axis, and the image-side surface thereof may be convex. The sixth lens may have negative optical power, the object-side surface thereof may be concave, and the image-side surface thereof may be convex. The seventh lens may have negative optical power, the object-side surface thereof may be convex at the near optical axis, and the image-side surface thereof may be concave at the near optical axis.

[0056] In some embodiments, the optical lens may further include an aperture, which may be located between the second and third lenses. It is understood that the aperture is used to limit the amount of light entering, thereby changing the brightness of the image. When the aperture is located between the second and third lenses, it facilitates correction of aperture aberrations.

[0057] In some embodiments, the optical lens may further include a filter disposed between the seventh lens and the imaging surface. The filter is used to filter out interfering light and prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0058] 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.

[0059] 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. Satisfying the above range and reasonably limiting the ratio of the maximum field of view to the aperture value can collect light at large angles and obtain good imaging quality. At the same time, it can 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°.

[0060] 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. Satisfying the above range can effectively limit the length of the lens and achieve miniaturization of the lens. At the same time, with the same overall length of the lens ensured, it has a larger image plane, can match a larger-size imaging chip to achieve high-definition imaging, and 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.

[0061] 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. Satisfying the above range and reasonably controlling the ratio of the image height to the focal length of the optical lens helps the optical lens to have the characteristic of a large image plane, improve the resolution of the lens, and further improve the imaging quality. At the same time, limiting the optical lens to have an appropriate back focus facilitates the reasonable arrangement of the positions of each lens, reduces the processing and assembly difficulty, is conducive to reducing the interference between different components, and improves the yield. More specifically: 3.38 < IH / f < 4.12.

[0062] 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 angle of the optical lens, and the maximum field 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 geometric shape of the optical lens and improve its structural stability. At the same time, reasonably limiting the proportion of the optical power of the rear lens group of the aperture is beneficial to correcting the chromatic aberration and field curvature of the optical system, as well as slowing down the light deflection angle, reducing the sensitivity, and reducing the lens forming difficulty. More specifically: 1.75 < f34567 / f < 2.2.

[0063] 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 as much edge field light as possible into the rear system, achieve large-angle light collection, and thus achieve 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.

[0064] 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.

[0065] 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 limits the appropriate proportion of the optical power of the third lens, the fourth lens, and the fifth lens, which 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.

[0066] 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.

[0067] 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 rays, increase the area of light rays 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.

[0068] 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, controlling the second lens and the sixth lens to have appropriate surface shapes is beneficial to reducing the correction difficulty of aberration and distortion and improving the overall imaging quality. More specifically: 0.34 < (R3 - R4) / (R3 + R4) < 0.51; -3.38 < (R11 + R12) / (R11 - R12) < -2.54.

[0069] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 6 < IH / EPD < 8.5. Satisfying the above range can increase the width of the light beam entering the optical lens, improve the relative illuminance, and avoid vignetting. More specifically: 6.07 < IH / EPD < 8.23.

[0070] 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, controlling the total optical length of the optical lens and the sum of the central thicknesses of each lens within a reasonable range helps to achieve high pixel characteristics and improve the imaging quality of the optical lens.

[0071] 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, controlling the effective focal length of the optical lens and the sum of the central thicknesses of each lens within a reasonable range can make the lens more compact.

[0072] 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.

[0073] 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 controls the first lens to have an appropriate surface shape, which is beneficial to collecting as much marginal field light as possible into the subsequent system, achieving large-angle light collection, and thus achieving ultra-wide-angle imaging of the lens. More specifically: 1.64 < (R1 + R2) / (R1 - R2) < 1.81.

[0074] 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 total optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, CRA represents the principal ray incident angle at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above 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.

[0075] 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.

[0076] In some embodiments, the first, second, third, fourth, fifth, sixth, and seventh lenses may be spherical or aspherical lenses. Compared to spherical lenses, aspherical structures can effectively reduce aberrations in the optical system, thereby reducing the number and size of lenses and achieving better miniaturization. More specifically, the first, second, third, fourth, fifth, sixth, and seventh lenses of the present invention may all be aspherical lenses.

[0077] In various embodiments of the present invention, when the lens is an aspheric lens, the shapes of the aspheric surfaces of the optical lens satisfy the following equations:

[0078] ;

[0079] Where z is the distance between the surface and the vertex 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, and B, C, D, E, and F are the fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order surface coefficients, respectively.

[0080] The present invention is further illustrated below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens vary; for details, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any other changes, substitutions, combinations, or simplifications that do not deviate from the novelties of the present invention shall be considered equivalent replacements and are included within the scope of protection of the present invention.

[0081] Example 1

[0082] See also Figure 1 , shown is a schematic structural diagram of the optical lens 100 provided in Example 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and a filter G1.

[0083] The first lens L1 has negative refractive power, its object-side surface S1 is convex near the optical axis, and its image-side surface S2 is concave;

[0084] The second lens L2 has positive refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0085] The third lens L3 has positive refractive power, its object-side surface S5 is convex near the optical axis, and its image-side surface S6 is convex;

[0086] The fourth lens L4 has negative refractive power, its object-side surface S7 is convex at the near optical axis, and its image-side surface S8 is concave at the near optical axis;

[0087] The fifth lens L5 has positive refractive power, its object-side surface S9 is convex near the optical axis, and its image-side surface S10 is convex;

[0088] The sixth lens L6 has negative refractive power, its object-side surface S10 is concave, and its image-side surface S11 is convex;

[0089] The fifth lens L5 and the sixth lens L6 form a cemented lens group. That is, the cemented surface between the image-side surface of the fifth lens L5 and the object-side surface of the sixth lens L6 is S10.

[0090] The seventh lens L7 has negative refractive power, its object-side surface S12 is convex near the optical axis, and its image-side surface S13 is concave near the optical axis;

[0091] The object-side surface S14 and the image-side surface S15 of the filter G1 are both flat surfaces;

[0092] The imaging surface S16 is a plane.

[0093] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all plastic aspherical lenses.

[0094] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0095] Table 1-1

[0096]

[0097] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0098] Table 1-2

[0099]

[0100] In this embodiment, the F-Theta distortion curve and the MTF curve of the optical lens 100 are respectively as follows: Figure 2 、 Figure 3 shown.

[0101] Figure 2 The F-Theta distortion curve of this embodiment is shown, which shows the distortion at different field angles on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the distortion value is controlled within 0% to 40%, indicating that the optical lens 100 is capable of correcting distortion.

[0102] Figure 3 The MTF (Modulation Transfer Function) curve for Example 1 is shown. It represents the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this example is consistently above 0.4 across the entire field of view. Within the range of 0 to 90 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0103] Example 2

[0104] See also Figure 4 , shown is a schematic structural diagram of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0105] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0106] Table 2-1

[0107]

[0108] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0109] Table 2-2

[0110]

[0111] In this embodiment, the F-Theta distortion curve and the MTF curve of the optical lens 200 are respectively as follows: Figure 5 、 Figure 6 As shown. Figure 5 It can be seen from the figure that the distortion value is controlled within 0%~30%, indicating that the optical lens 200 can correct the distortion. Figure 6 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 90 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating good imaging quality and detail resolution in both low-frequency and high-frequency conditions.

[0112] Example 3

[0113] See also Figure 7 , shown is a schematic structural diagram of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main difference between this embodiment is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0114] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0115] Table 3-1

[0116]

[0117] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0118] Table 3-2

[0119]

[0120] In this embodiment, the F-Theta distortion curve and the MTF curve of the optical lens 300 are respectively as follows: Figure 8 、 Figure 9 As shown. Figure 8 It can be seen from the figure that the distortion value is controlled within 0%~35%, indicating that the optical lens 300 can correct the distortion. Figure 9 As can be seen, the MTF value of this embodiment is above 0.4 throughout the entire field of view. In the range of 0 to 90 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, achieving good imaging quality and detail resolution in both low-frequency and high-frequency conditions.

[0121] Example 4

[0122] See also Figure 10 , shown is a schematic structural diagram of an optical lens 400 provided in Example 4 of the present invention. Compared with Example 1, the main difference between this embodiment is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0123] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0124] Table 4-1

[0125]

[0126] The surface parameters of the aspheric lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0127] Table 4-2

[0128]

[0129] In this embodiment, the F-Theta distortion curve and the MTF curve of the optical lens 400 are respectively as follows: Figure 11 、 Figure 12 As shown. Figure 11 It can be seen from the figure that the distortion value is controlled within -10%~20%, indicating that the optical lens 400 can correct the distortion. Figure 12 As can be seen, the MTF value of this embodiment is above 0.5 throughout the entire field of view. In the range of 0 to 90 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, achieving good imaging quality and detail resolution in both low-frequency and high-frequency conditions.

[0130] Example 5

[0131] See also Figure 13 , shown is a schematic structural diagram of the optical lens 500 provided in Example 5 of the present invention. Compared with Example 1, the main difference between this embodiment is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0132] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0133] Table 5-1

[0134]

[0135] The surface parameters of the aspheric lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0136] Table 5-2

[0137]

[0138] In this embodiment, the F-Theta distortion curve and the MTF curve of the optical lens 500 are respectively as follows: Figure 14 、 Figure 15 As shown. Figure 14 It can be seen from the figure that the distortion value is controlled within 0%~45%, indicating that the optical lens 500 can correct the distortion. Figure 15 As can be seen, the MTF value of this embodiment is above 0.6 throughout the entire field of view. In the range of 0 to 90 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating good imaging quality and detail resolution in both low-frequency and high-frequency conditions.

[0139] Example 6

[0140] See also Figure 16 , shown is a schematic structural diagram of an optical lens 600 provided in Example 6 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0141] The relevant parameters of each lens in the optical lens 600 in Example 6 are shown in Table 6-1.

[0142] Table 6-1

[0143]

[0144] The surface parameters of the aspheric lens of the optical lens 600 in Example 6 are shown in Table 6-2.

[0145] Table 6-2

[0146]

[0147] In this embodiment, the F-Theta distortion curve and the MTF curve of the optical lens 600 are respectively as follows: Figure 17 、 Figure 18 As shown. Figure 17 It can be seen from the figure that the distortion value is controlled within 0%~30%, indicating that the optical lens 600 can correct the distortion. Figure 18 As can be seen, the MTF value of this embodiment is above 0.5 throughout the entire field of view. In the range of 0 to 90 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, achieving good imaging quality and detail resolution in both low-frequency and high-frequency conditions.

[0148] Example 7

[0149] See also Figure 19 , shown is a schematic structural diagram of an optical lens 700 provided in Example 7 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0150] The relevant parameters of each lens in the optical lens 700 in Example 7 are shown in Table 7-1.

[0151] Table 7-1

[0152]

[0153] The surface parameters of the aspheric lens of the optical lens 700 in Example 7 are shown in Table 7-2.

[0154] Table 7-2

[0155]

[0156] In this embodiment, the F-Theta distortion curve and the MTF curve of the optical lens 700 are respectively as follows: Figure 20 、 Figure 21 As shown. Figure 20It can be seen from the figure that the distortion value is controlled within 0%~40%, indicating that the optical lens 700 can correct the distortion. Figure 21 As can be seen, the MTF value of this embodiment is above 0.4 throughout the entire field of view. In the range of 0 to 90 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, achieving good imaging quality and detail resolution in both low-frequency and high-frequency conditions.

[0157] Please refer to Table 8-1 and Table 8-2, which show the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, chief ray incidence angle CRA at maximum image height, real image height IH corresponding to 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 numerical value corresponding to each conditional expression in each embodiment.

[0158] Table 8-1

[0159]

[0160] Table 8-2

[0161]

[0162] In summary, the optical lens provided by the present invention uses seven lenses with specific optical powers. Through the combination of specific surface shapes and reasonable optical power distribution, it is possible to improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, so that the lens has one or more advantages such as ultra-wide angle, large image surface, and large aperture.

[0163] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0164] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An optical lens, comprising seven lenses, characterized in that: It successively includes from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side surface is convex near the optical axis and whose image side surface is concave; A second lens with a positive optical power, whose object side surface is concave and whose image side surface is convex; A third lens with a positive optical power, whose object side surface is convex near the optical axis and whose image side surface is convex; A fourth lens with a negative optical power, whose object side surface is convex near the optical axis and whose image side surface is concave near the optical axis; A fifth lens with a positive optical power, whose object side surface is convex near the optical axis and whose image side surface is convex; A sixth lens with a negative optical power, whose object side surface is concave and whose image side surface is convex; A seventh lens with a negative optical power, whose object side surface is convex near the optical axis and whose image side surface is concave near the optical axis; Wherein, the maximum field 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 angle of the optical lens, the effective focal length f of the optical lens and the radian value θ of the maximum half field 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 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 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, wherein: The clear aperture semi-diameter d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 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.

5. The optical lens according to claim 1, wherein: 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.

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 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.

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, wherein: 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.

Images