Optical lens

Abstract

The present invention provides an optical lens comprising seven lenses, which, along the optical axis, from the object side to the imaging surface, comprise: a first lens having negative optical power, whose object side surface is concave and whose image side surface is concave; a second lens having positive optical power; a third lens having positive optical power; a fourth lens having positive optical power, whose object side surface is convex and whose image side surface is convex; a fifth lens having negative optical power, whose object side surface is concave and whose image side surface is concave; a sixth lens having positive 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 concave and whose image side surface is convex. The optical lens provided by the present invention has one or more advantages, including a large target surface, a large aperture, and small distortion.

Description

Technical Field

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

[0002] With the booming development of assisted driving and autonomous driving technologies, in-vehicle cameras play a crucial role. There are various types of in-vehicle cameras, including interior, rear, front, side, and surround view cameras. Each has unique functions and serves different application scenarios. For example, a forward-looking wide-angle camera is primarily used to accurately identify close-range objects, providing critical information for driving in urban road conditions and low-speed driving scenarios.

[0003] Forward-facing cameras are a core component of ADAS (Advanced Driver Assistance Systems). They not only measure distance but also accurately identify objects and clearly discern road markings. This requires extremely complex visual algorithms and a high technical barrier to entry. To fully leverage the performance of forward-facing cameras, developing an optical lens with superior imaging quality is imperative. Only by doing so can they ensure stable and efficient operation in complex driving environments, laying a solid foundation for the further development of autonomous driving technology. Summary of the Invention

[0004] 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.

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

[0006] An optical lens, comprising seven lenses, including the following elements in order from the object side to the imaging surface along the optical axis:

[0007] The first lens has a negative optical power, and its object-side surface is concave and its image-side surface is concave;

[0008] a second lens having positive optical power;

[0009] a third lens having positive optical power;

[0010] a fourth lens element having positive refractive power, whose object-side surface is convex and whose image-side surface is convex;

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

[0012] a sixth lens element having positive refractive power, whose object-side surface is concave and whose image-side surface is convex;

[0013] a seventh lens element having negative optical power, whose object-side surface is concave and whose image-side surface is convex;

[0014] Among them, the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: -0.6 < (R13 - R14) / (R13 + R14) < -0.2; the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: -0.8 < (R1 + R2) / (R1 - R2) < -0.4.

[0015] Further preferably, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.8 < TTL / f < 2.3; 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: 3 < TTL / IH < 3.7.

[0016] Further preferably, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 21° < FOV / Fno < 22°; the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 0.9 < IH / EPD < 1.1.

[0017] Further preferably, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.26 < BFL / f < 0.33; the back focal length BFL of the optical lens and the overall optical length TTL of the optical lens satisfy: 0.11 < BFL / TTL < 0.17.

[0018] 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 angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 3.6 < d1 / (IH / 2) / tan(FOV / 2) < 4.5; 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: 0.8 < f34567 / f < 1.8.

[0019] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -1.7 < f1 / f < -0.5; the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -1.7 < R1 / f < -0.5; the curvature radius R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 1.8 < R2 / f < 5.6.

[0020] More preferably, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.7 < f4 / f < 0.9; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.6 < R7 / f < 1.1; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -2.1 < R8 / f < -0.6.

[0021] More preferably, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 1 < f6 / f < 1.7; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: -18 < R11 / f < -3; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.1 < R12 / f < -0.7.

[0022] More preferably, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8 < f7 / f < -1.1; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -0.6 < R13 / f < -0.4; the image-side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8 < R14 / f < -0.7.

[0023] More preferably, the object-side curvature radius R11 of the sixth lens and the image-side curvature radius R12 of the sixth lens satisfy: 0.5 < (R11 - R12) / (R11 + R12) < 1; the object-side curvature radius R7 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy: |(R7 + R8) / (R7 - R8)| < 0.6.

[0024] 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 a large target surface, a large aperture, and low distortion. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, where:

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

[0027] Figure 2 is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 3 Graph showing the F-Tan (Theta) distortion of the optical lens in Example 1 of the present invention.

[0029] Figure 4 This is the MTF curve of the optical lens in Example 1 of the present invention.

[0030] Figure 5 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0031] Figure 6 Graph showing the field curvature of the optical lens in Example 2 of the present invention.

[0032] Figure 7 FIG. 4 is a graph showing the F-Tan (Theta) distortion curve of the optical lens in Example 2 of the present invention.

[0033] Figure 8 This is an MTF curve diagram of the optical lens in Example 2 of the present invention.

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

[0035] Figure 10 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0036] Figure 11 Graph showing the F-Tan (Theta) distortion of the optical lens in Example 3 of the present invention.

[0037] Figure 12 This is the MTF curve of the optical lens in Example 3 of the present invention.

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

[0039] Figure 14 4 is a field curvature curve diagram of the optical lens in Example 4 of the present invention.

[0040] Figure 15 Graph showing the F-Tan (Theta) distortion of the optical lens in Example 4 of the present invention.

[0041] Figure 16 This is the MTF curve of the optical lens in Example 4 of the present invention.

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

[0043] Figure 18 4 is a field curvature curve diagram of the optical lens in Example 5 of the present invention.

[0044] Figure 19 FIG. 5 is a graph showing the F-Tan (Theta) distortion curve of the optical lens in Example 5 of the present invention.

[0045] Figure 20 This is the MTF curve of the optical lens in Example 5 of the present invention.

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

[0047] Figure 22 4 is a field curvature curve diagram of the optical lens in Example 6 of the present invention.

[0048] Figure 23 FIG. 4 is a graph showing the F-Tan (Theta) distortion curve of the optical lens in Example 6 of the present invention.

[0049] Figure 24 This is the MTF curve of the optical lens in Example 6 of the present invention.

[0050] Figure 25 Schematic diagram of the structure of the optical lens in Example 7 of the present invention.

[0051] Figure 26 4 is a field curvature curve diagram of the optical lens in Example 7 of the present invention.

[0052] Figure 27 FIG. 4 is a graph showing the F-Tan (Theta) distortion curve of the optical lens in Example 7 of the present invention.

[0053] Figure 28 This is the MTF curve of the optical lens in Example 7 of the present invention.

[0054] Figure 29 Schematic diagram of the structure of the optical lens in Example 8 of the present invention.

[0055] Figure 30 4 is a field curvature curve diagram of the optical lens in Example 8 of the present invention.

[0056] Figure 31 FIG. 4 is a graph showing the F-Tan (Theta) distortion curve of the optical lens in Example 8 of the present invention.

[0057] Figure 32 This is the MTF curve of the optical lens in Example 8 of the present invention.

[0058] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

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

[0068] 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.

[0069] In some embodiments, the optical lens may further include a filter and a protective glass, positioned sequentially along the optical axis between the seventh lens element and the imaging surface. The filter is used to filter out interfering light, preventing it from reaching the imaging surface of the optical lens and affecting normal imaging. The protective glass protects the optical lens from damage to the photosensitive chip and improves the optical lens's impact and scratch resistance, while having little impact on the imaging quality of the optical lens.

[0070] In some embodiments, the fourth lens and the fifth lens can be cemented to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the decentration sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the difficulty of the optical lens processing technology and improving the assembly yield of the optical lens.

[0071] In some embodiments, the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: -0.6 < (R13 - R14) / (R13 + R14) < -0.2; 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: -0.8 < (R1 + R2) / (R1 - R2) < -0.4. Satisfying the above ranges, controlling the seventh lens and the first lens to have appropriate surface profiles is beneficial to increasing the divergence degree of light, achieving large target surface imaging of the lens, and improving the imaging quality of the optical lens. More specifically: -0.56 < (R13 - R14) / (R13 + R14) < -0.23; -0.77 < (R1 + R2) / (R1 - R2) < -0.48.

[0072] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.8 < TTL / f < 2.3; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 3 < TTL / IH < 3.7. Satisfying the above ranges is beneficial to achieving the balance of small volume and large image surface of the optical lens, and making the lens have a smaller total length. More specifically: 1.91 < TTL / f < 2.22; 3.06 < TTL / IH < 3.58.

[0073] In some embodiments, the maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 21° < FOV / Fno < 22°; the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 0.9 < IH / EPD < 1.1. Satisfying the above ranges, reasonably limiting the ratio of the field angle to the f-number, can collect light at large angles and obtain good imaging quality. At the same time, reasonably limiting the ratio of the image height to the entrance pupil diameter is beneficial to increasing the light transmission amount, making the peripheral field and the central field brightness more uniform. More specifically: 21.2° < FOV / Fno < 21.89°; 0.98 < IH / EPD < 1.04.

[0074] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.26 < BFL / f < 0.33; the back focal length BFL of the optical lens and the total optical length TTL of the optical lens satisfy: 0.11 < BFL / TTL < 0.17. Satisfying the above ranges, limiting the optical lens to have an appropriate back focus is convenient for reasonably arranging the positions of each lens, and at the same time reduces the processing and assembly difficulty. At the same time, it is beneficial to reduce the interference between different components and improve the yield.

[0075] In some embodiments, the clear aperture radius 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: 3.6 < d1 / (IH / 2) / tan(FOV / 2) < 4.5; 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: 0.8 < f34567 / f < 1.8. Meeting 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, lowering the sensitivity, and reducing the lens forming difficulty. More specifically: 3.65 < d1 / (IH / 2) / tan(FOV / 2) < 4.47; 0.82 < f34567 / f < 1.77.

[0076] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -1.7 < f1 / f < -0.5; 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: -1.7 < R1 / f < -0.5; 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: 1.8 < R2 / f < 5.6. Meeting the above ranges can diverge the light passing through it by reasonably limiting the proportion of the optical power of the first lens and its surface shape, which is beneficial to achieving a small front aperture. More specifically: -1.57 < f1 / f < -0.57; -1.63 < R1 / f < -0.59; 1.88 < R2 / f < 5.59.

[0077] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.7 < f4 / f < 0.9; the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 0.6 < R7 / f < 1.1; the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -2.1 < R8 / f < -0.6. Meeting the above ranges can effectively correct the aberration of the optical lens and improve the imaging quality by reasonably limiting the proportion of the optical power of the fourth lens and its surface shape. More specifically: 0.71 < f4 / f < 0.89; 0.65 < R7 / f < 1.04; -2.06 < R8 / f < -0.69.

[0078] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 1 < f6 / f < 1.7; the radius of curvature R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -18 < R11 / f < -3; the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -1.1 < R12 / f < -0.7. Meeting the above ranges, by reasonably defining the proportion of the optical power of the sixth lens and its surface shape, it is beneficial to the convergence of light, enables the light trend to smoothly transition to the rear, reduces the height of the light incident on the rear, slows down the upward trend of the light, and is beneficial to improving the illuminance of the edge field of view. More specifically: 1.07 < f6 / f < 1.64; -17.66 < R11 / f < -3.27; -1.04 < R12 / f < -0.76.

[0079] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8 < f7 / f < -1.1; the radius of curvature R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -0.6 < R13 / f < -0.4; the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8 < R14 / f < -0.7. Meeting the above ranges, by reasonably defining the proportion of the optical power of the seventh lens and its surface shape, it is beneficial to increase the degree of divergence of light, increase the area of light entering the imaging surface, achieve large target surface imaging of the lens, and improve the imaging quality of the optical lens. More specifically: -1.77 < f7 / f < -1.19; -0.53 < R13 / f < -0.41; -1.76 < R14 / f < -0.7.

[0080] In some embodiments, 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: 0.5 < (R11 - R12) / (R11 + R12) < 1; the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: |(R7 + R8) / (R7 - R8)| < 0.6. Meeting the above ranges, controlling the sixth lens and the fourth lens to have appropriate surface shapes is beneficial to the convergence of light, enables the light trend to smoothly transition to the rear, reduces the height of the light incident on the rear, slows down the upward trend of the light, and is beneficial to improving the illuminance of the edge field of view. Moreover, it can effectively correct the aberration of the optical lens and improve the imaging quality. More specifically: 0.53 < (R11 - R12) / (R11 + R12) < 0.91; -0.45 < (R7 + R8) / (R7 - R8) < 0.2.

[0081] In some embodiments, 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 maximum field angle FOV of the optical lens satisfy: 0.97 < (IH / 2) / (f × tan(FOV / 2)) < 1.01. Meeting the above range can control the optical lens to have less distortion and improve the imaging quality.

[0082] In some embodiments, the sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis and the total optical length TTL of the optical lens satisfy: 0.58 < ΣCT / TTL < 0.7. Meeting 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.

[0083] In some embodiments, the sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis and the effective focal length f of the optical lens satisfy: 1. |13 < ΣCT / f < 1.53. Meeting 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.

[0084] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 0.8 < f2 / f < 1.7. Meeting the above range, by reasonably limiting the proportion of the optical power of the second lens, it has the effect of converging light rays, depressing the height of peripheral light rays, and is beneficial to reducing the aperture of the rear lens. More specifically: 0.8 < f2 / f < 1.56.

[0085] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.9 < f3 / f < 2.4. Meeting the above range, by reasonably limiting the proportion of the optical power of the third lens, the aberration generated at the front end of the lens can be effectively corrected, improving the imaging quality of the lens. More specifically: 0.96 < f3 / f < 2.38.

[0086] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -0.7 < f5 / f < -0.4; the object-side curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: -2.1 < R9 / f < -0.6; the image-side curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.5 < R10 / f < 1. Meeting the above range, reasonably limiting the proportion of the optical power of the fifth lens and its surface shape can optimize spherical aberration and achieve high-quality imaging. More specifically: -0.65 < f5 / f < -0.45; -2.06 < R9 / f < -0.69; 0.52 < R10 / f < 0.92.

[0087] In some embodiments, the optical lens satisfies the following conditional expressions: 14 mm < f < 16 mm; 30° < FOV < 40°; 9 mm < EPD < 10 mm; 29 mm < TTL < 33 mm; 1.5 < Fno < 1.7; 8.5 mm < IH < 10 mm; 17° < CRA < 22°; 3.5 mm < BFL < 5.5 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, CRA represents the chief ray angle of incidence at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above ranges, the optical lens has at least one or more advantages such as a large target surface, a large aperture, and low distortion. More specifically: 14.47 mm < f < 15.62 mm; 34° < FOV < 36°; 9.04 mm < EPD < 9.76 mm; 29.23 mm < TTL < 32.07 mm; 1.59 < Fno < 1.66; 8.97 mm < IH < 9.76 mm; 17.31° < CRA < 21.59°; 3.96 mm < BFL < 5.01 mm.

[0088] 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. Additionally, when the lens material is glass, due to the low dispersion characteristic of glass itself, the geometric chromatic aberration of the optical system can be effectively corrected. The optical lens provided by the present invention can adopt an all-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

[0089] 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 can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better achieving miniaturization of the lens. More specifically, the second lens of the present invention adopts an aspherical lens, and the first lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens adopt spherical lenses.

[0090] In various embodiments of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0091] ;

[0092] 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.

[0093] 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.

[0094] Example 1

[0095] 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, a filter G1, and a protective glass G2.

[0096] The first lens L1 has negative refractive power, its object-side surface S1 is concave, and its image-side surface S2 is concave;

[0097] The second lens L2 has positive refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave;

[0098] The third lens L3 has positive refractive power, its object-side surface S5 is convex, and its image-side surface S6 is convex;

[0099] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is convex;

[0100] The fifth lens L5 has negative refractive power, its object-side surface S8 is concave, and its image-side surface S9 is concave;

[0101] The fourth lens L4 and the fifth lens L5 form a cemented lens group, that is, the cemented surface between the image-side surface of the fourth lens L4 and the object-side surface of the fifth lens L5 is S8;

[0102] The sixth lens L6 has positive refractive power, its object-side surface S10 is concave, and its image-side surface S11 is convex;

[0103] The seventh lens L7 has negative refractive power, its object-side surface S12 is concave, and its image-side surface S13 is convex;

[0104] The object-side surface S14 and the image-side surface S15 of the filter G1 are both flat surfaces;

[0105] The object side surface S16 and the image side surface S17 of the protective glass G2 are both flat surfaces;

[0106] The imaging surface S18 is a plane.

[0107] The second lens L2 is a glass aspherical lens, and the first lens L1, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are glass spherical lenses.

[0108] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0109] Table 1-1

[0110]

[0111] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0112] Table 1-2

[0113]

[0114] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 100 are shown as follows: Figure 2 、 Figure 3 、 Figure 4 shown.

[0115] Figure 2 The following is a graph of field curvature for Example 1, showing the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: degrees). As can be seen from the graph, the field curvature of the meridional and sagittal image planes is controlled within ±0.06mm, indicating that the optical lens 100 is capable of effectively correcting field curvature.

[0116] Figure 3 The F-Tan (Theta) distortion curve for Example 1 is shown. It represents the distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the graph, the distortion of the optical lens is controlled within a range of -0.2% to 0%, indicating that the optical lens 100 is capable of effectively correcting distortion.

[0117] Figure 4The 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 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edges of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0118] Example 2

[0119] See also Figure 5 , shown is a schematic structural diagram of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, this embodiment has the following main differences: the object-side surface S3 of the second lens L2 is concave, and the image-side surface S4 is convex; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0120] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0121] Table 2-1

[0122]

[0123] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0124] Table 2-2

[0125]

[0126] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 200 are shown as follows: Figure 6 、 Figure 7 、 Figure 8 As shown. Figure 6 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.08mm~0.04mm, indicating that the optical lens 200 can well correct the field curvature. Figure 7 It can be seen from the figure that the distortion of the optical lens 200 is controlled within -1.8% to 0%, indicating that the optical lens 200 can correct the distortion well. Figure 8 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 120 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 at both low and high frequencies.

[0127] Example 3

[0128] See also Figure 9 , shown is a schematic structural diagram of an optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image-side surface S4 of the second lens L2 is convex; the object-side surface S5 of the third lens L3 is concave; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0129] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0130] Table 3-1

[0131]

[0132] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0133] Table 3-2

[0134]

[0135] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 300 are shown as follows: Figure 10 、 Figure 11 、 Figure 12 As shown. Figure 10 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.04mm, indicating that the optical lens 300 can well correct the field curvature. Figure 11 It can be seen from the figure that the distortion of the optical lens 300 is controlled within -0.9% to 0%, indicating that the optical lens 300 can correct the distortion well. Figure 12 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 120 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 at both low and high frequencies.

[0136] Example 4

[0137] See also Figure 13 , shown is a schematic structural diagram of an optical lens 400 provided in Example 4 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image side surface S4 of the second lens L2 is convex; the image side surface S6 of the third lens L3 is concave; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0138] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0139] Table 4-1

[0140]

[0141] The surface parameters of the aspheric lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0142] Table 4-2

[0143]

[0144] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 400 are shown as follows: Figure 14 、 Figure 15 、 Figure 16 As shown. Figure 14 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.04mm, indicating that the optical lens 400 can well correct the field curvature. Figure 15 It can be seen from the figure that the distortion of the optical lens 400 is controlled within -1%~0%, indicating that the optical lens 400 can correct the distortion well. Figure 16 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 120 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.

[0145] Example 5

[0146] See also Figure 17 , shown is a schematic structural diagram of an optical lens 500 provided in Example 5 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image side surface S4 of the second lens L2 is convex; the image side surface S6 of the third lens L3 is concave; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0147] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0148] Table 5-1

[0149]

[0150] The surface parameters of the aspheric lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0151] Table 5-2

[0152]

[0153] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 500 are shown as follows: Figure 18 、 Figure 19 、 Figure 20 As shown. Figure 18 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.04mm, indicating that the optical lens 500 can well correct the field curvature. Figure 19 It can be seen from the figure that the distortion of the optical lens 500 is controlled within -1.2%~0%, indicating that the optical lens 500 can correct the distortion well. Figure 20 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 120 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.

[0154] Example 6

[0155] See also Figure 21 , shown is a schematic structural diagram of an optical lens 600 provided in Example 6 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image-side surface S4 of the second lens L2 is convex; the object-side surface S5 of the third lens L3 is concave; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0156] The relevant parameters of each lens in the optical lens 600 in Example 6 are shown in Table 6-1.

[0157] Table 6-1

[0158]

[0159] The surface parameters of the aspheric lens of the optical lens 600 in Example 6 are shown in Table 6-2.

[0160] Table 6-2

[0161]

[0162] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 600 are shown as follows: Figure 22 、 Figure 23 、 Figure 24 As shown. Figure 22 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.04mm~0.06mm, indicating that the optical lens 600 can well correct the field curvature. Figure 23It can be seen from the figure that the distortion of the optical lens 600 is controlled within -1.2%~0%, indicating that the optical lens 600 can correct the distortion well. Figure 24 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 120 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.

[0163] Example 7

[0164] See also Figure 25 , shown is a schematic structural diagram of an optical lens 700 provided in Example 7 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the image-side surface S4 of the second lens L2 is a convex surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0165] The relevant parameters of each lens in the optical lens 700 in Example 7 are shown in Table 7-1.

[0166] Table 7-1

[0167]

[0168] The surface parameters of the aspheric lens of the optical lens 700 in Example 7 are shown in Table 7-2.

[0169] Table 7-2

[0170]

[0171] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 700 are shown as follows: Figure 26 、 Figure 27 、 Figure 28 As shown. Figure 26 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.02mm~0.04mm, indicating that the optical lens 700 can well correct the field curvature. Figure 27 It can be seen from the figure that the distortion of the optical lens 700 is controlled within -1.2%~0%, indicating that the optical lens 700 can correct the distortion well. Figure 28 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 120 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.

[0172] Example 8

[0173] See also Figure 29 , shown is a schematic structural diagram of an optical lens 800 provided in Example 8 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the image-side surface S4 of the second lens L2 is a convex surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0174] The relevant parameters of each lens in the optical lens 800 in Example 8 are shown in Table 8-1.

[0175] Table 8-1

[0176]

[0177] The surface parameters of the aspheric lens of the optical lens 800 in Example 8 are shown in Table 8-2.

[0178] Table 8-2

[0179]

[0180] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 800 are shown as follows: Figure 30 、 Figure 31 、 Figure 32 As shown. Figure 30 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.04mm~0.02mm, indicating that the optical lens 800 can well correct the field curvature. Figure 31 It can be seen from the figure that the distortion of the optical lens 800 is controlled within -1.2%~0%, indicating that the optical lens 800 can correct the distortion well. Figure 32 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 120 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.

[0181] Please refer to Table 9-1 and Table 9-2, 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.

[0182] Table 9-1

[0183]

[0184] Table 9-2

[0185]

[0186] 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 a large target area, a large aperture, and small distortion.

[0187] 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.

[0188] 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 sequentially includes from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side is concave and whose image side is concave; A second lens with a positive optical power; A third lens with a positive optical power; A fourth lens with a positive optical power, whose object side is convex and whose image side is convex; A fifth lens with a negative optical power, whose object side is concave and whose image side is concave; A sixth lens with a positive 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 concave and whose image side is convex; Wherein, the curvature radius R13 of the object side of the seventh lens and the curvature radius R14 of the image side of the seventh lens satisfy: -0.6 < (R13 - R14) / (R13 + R14) < -0.2; the curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side of the first lens satisfy: -0.8 < (R1 + R2) / (R1 - R2) < -0.4; the clear aperture radius d1 of the object side 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: 3.6 < d1 / (IH / 2) / tan(FOV / 2) < 4.5; 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: 0.8 < f34567 / f < 1.

8.

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: 1.8 < TTL / f < 2.3; 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: 3 < TTL / IH < 3.

7.

3. The optical lens according to claim 1, wherein: The maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 21° < FOV / Fno < 22°; the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 0.9 < IH / EPD < 1.

1.

4. The optical lens according to claim 1, wherein: The back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.26 < BFL / f < 0.33; the back focal length BFL of the optical lens and the overall optical length TTL of the optical lens satisfy: 0.11 < BFL / TTL < 0.

17.

5. The optical lens according to claim 1, wherein: The radius of curvature R13 of the object side of the seventh lens and the radius of curvature R14 of the image side of the seventh lens satisfy: -0.56 < (R13 - R14) / (R13 + R14) < -0.23; the radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side of the first lens satisfy: -0.77 < (R1 + R2) / (R1 - R2) < -0.48; the clear aperture radius d1 of the object side 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: 3.65 < d1 / (IH / 2) / tan(FOV / 2) < 4.47; 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: 0.82 < f34567 / f < 1.

77.

6. 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: -1.7 < f1 / f < -0.5; the radius of curvature R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: -1.7 < R1 / f < -0.5; the radius of curvature R2 of the image side of the first lens and the effective focal length f of the optical lens satisfy: 1.8 < R2 / f < 5.

6.

7. The optical lens according to claim 1, wherein: The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.7 < f4 / f < 0.9; the radius of curvature R7 of the object side of the fourth lens and the effective focal length f of the optical lens satisfy: 0.6 < R7 / f < 1.1; the radius of curvature R8 of the image side of the fourth lens and the effective focal length f of the optical lens satisfy: -2.1 < R8 / f < -0.

6.

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: 1 < f6 / f < 1.7; the radius of curvature R11 of the object side of the sixth lens and the effective focal length f of the optical lens satisfy: -18 < R11 / f < -3; the radius of curvature R12 of the image side of the sixth lens and the effective focal length f of the optical lens satisfy: -1.1 < R12 / f < -0.

7.

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: -1.8 < f7 / f < -1.1; the radius of curvature R13 of the object side of the seventh lens and the effective focal length f of the optical lens satisfy: -0.6 < R13 / f < -0.4; the radius of curvature R14 of the image side of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8 < R14 / f < -0.

7.

10. The optical lens according to claim 1, wherein: The radius of curvature R11 of the object side of the sixth lens and the radius of curvature R12 of the image side of the sixth lens satisfy: 0.5 < (R11 - R12) / (R11 + R12) < 1; the radius of curvature R7 of the object side of the fourth lens and the radius of curvature R8 of the image side of the fourth lens satisfy: |(R7 + R8) / (R7 - R8)| < 0.6.

Images