Optical lens

Abstract

The present invention provides an optical lens, comprising eight lenses, characterized in that, along the optical axis, from the object side to the imaging surface, the following are arranged in order: a first lens having negative optical power, whose image side surface is a concave surface; a second lens having negative optical power, whose object side surface is a concave surface and whose image side surface is a convex surface; a third lens having positive optical power, whose object side surface is a convex surface and whose image side surface is a concave surface; a fourth lens having positive optical power, whose object side surface is a convex surface; an aperture; a fifth lens having positive optical power, whose object side surface is a convex surface; a sixth lens having positive optical power, whose image side surface is a convex surface; a seventh lens having negative optical power, whose object side surface is a concave surface and whose image side surface is a convex surface; and an eighth lens having negative optical power, whose image side surface is a concave surface. The total optical length TTL and the effective focal length f of the optical lens satisfy the following conditions: TTL / f<7.0.

Description

Technical Field

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

[0002] With the development of intelligent automobiles, the vehicle's assisted driving system has gradually improved. As one of the main tools for the assisted driving system to obtain external information, the performance of the on-board camera directly affects the performance of the assisted driving system.

[0003] In order to accurately obtain external information, automotive lenses need to be equipped with larger and higher-resolution chips. At the same time, in order to adapt to the narrow installation space inside the car, automotive lenses not only require the front diameter to be as small as possible but also require the overall volume to be not too large. In addition, strong light transmission ability and the ability to adapt to changes in light and dark in the external environment are also special requirements for automotive lenses. Summary of the Invention

[0004] In view of the above problems, the purpose of the present invention is to provide an optical lens that can solve one or more of the above technical problems.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] An optical lens having eight lenses, characterized in that, along the optical axis from the object side to the imaging surface, the following are arranged in order:

[0007] a first lens having negative optical power and a concave image-side surface;

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

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

[0010] a fourth lens element having positive optical power and a convex object-side surface;

[0011] Aperture;

[0012] a fifth lens element having positive optical power and a convex object-side surface;

[0013] a sixth lens element having positive refractive power and a convex image-side surface;

[0014] The seventh lens element has a negative optical power, its object-side surface is concave and its image-side surface is convex;

[0015] an eighth lens element having negative optical power and a concave image-side surface;

[0016] The total optical length TTL and the effective focal length f of the optical lens satisfy the following conditions: TTL / f<7.0.

[0017] Preferably, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle satisfy: TTL / IH<4.0.

[0018] Preferably, the optical back focus BFL of the optical lens and the effective focal length f satisfy: 0.45<BFL / f.

[0019] Preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.0<f1 / f<-1.0.

[0020] Preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -20.0<f2 / f<-4.0.

[0021] Preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.5<f3 / f<40.0.

[0022] Preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.5<f4 / f<4.0.

[0023] Preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.2<f5 / f<5.0.

[0024] Preferably, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -25.0<f8 / f<-5.5.

[0025] Preferably, the total optical length TTL of the optical lens and the sum ΣCT of the center thicknesses of the first to sixth lenses along the optical axis satisfy: 0.6<ΣCT / TTL<0.8.

[0026] Compared with the prior art, the beneficial effects of the present invention are: by reasonably matching the lens shapes and optical focal lengths of the lenses, the advantages of large image surface, high resolution, high illumination, small size, etc. are achieved.

[0027] Additional aspects and advantages of the present invention will be given in part in the description which follows and in part will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0029] Figure 1 Schematic diagram of the structure of the optical lens of Example 1 of the present invention.

[0030] Figure 2Graph showing the field curvature of the optical lens in Example 1 of the present invention.

[0031] Figure 3 2 is a graph showing the F-Tanθ distortion curve of the optical lens in Example 1 of the present invention.

[0032] Figure 4 This is a relative illumination curve diagram of the optical lens in Example 1 of the present invention.

[0033] Figure 5 This is the MTF curve of the optical lens in Example 1 of the present invention.

[0034] Figure 6 1 is an axial aberration curve diagram of the optical lens in Example 1 of the present invention.

[0035] Figure 7 Graph showing the vertical axis chromatic aberration of the optical lens in Example 1 of the present invention.

[0036] Figure 8 Schematic diagram of the structure of the optical lens of Example 2 of the present invention.

[0037] Figure 9 Graph showing the field curvature of the optical lens in Example 2 of the present invention.

[0038] Figure 10 2 is a graph showing the F-Tanθ distortion curve of the optical lens in Example 2 of the present invention.

[0039] Figure 11 This is a relative illumination curve diagram of the optical lens in Example 2 of the present invention.

[0040] Figure 12 This is an MTF curve diagram of the optical lens in Example 2 of the present invention.

[0041] Figure 13 Graph showing the axial aberration of the optical lens in Example 2 of the present invention.

[0042] Figure 14 Graph showing vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0043] Figure 15 Schematic diagram of the structure of the optical lens of Example 3 of the present invention.

[0044] Figure 16 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0045] Figure 17 2 is a graph showing the F-Tanθ distortion curve of the optical lens in Example 3 of the present invention.

[0046] Figure 18 This is a relative illumination curve diagram of the optical lens in Example 3 of the present invention.

[0047] Figure 19 This is the MTF curve of the optical lens in Example 3 of the present invention.

[0048] Figure 20 4 is an axial aberration curve diagram of the optical lens in Example 3 of the present invention.

[0049] Figure 21 Graph showing vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0050] Figure 22 Schematic diagram of the structure of the optical lens of Example 4 of the present invention.

[0051] Figure 23 4 is a field curvature curve diagram of the optical lens in Example 4 of the present invention.

[0052] Figure 24 4 is an F-Tanθ distortion curve of the optical lens in Example 4 of the present invention.

[0053] Figure 25 This is a relative illumination curve diagram of the optical lens in Example 4 of the present invention.

[0054] Figure 26 This is the MTF curve of the optical lens in Example 4 of the present invention.

[0055] Figure 27 4 is an axial aberration curve diagram of the optical lens in Example 4 of the present invention.

[0056] Figure 28 Graph showing vertical axis chromatic aberration of the optical lens in Example 4 of the present invention.

[0057] Figure 29 Schematic diagram of the structure of the optical lens of Example 5 of the present invention.

[0058] Figure 30 4 is a field curvature curve diagram of the optical lens in Example 5 of the present invention.

[0059] Figure 31 4 is an F-Tanθ distortion curve of the optical lens in Example 5 of the present invention.

[0060] Figure 32 This is a relative illumination curve diagram of the optical lens in Example 5 of the present invention.

[0061] Figure 33 This is the MTF curve of the optical lens in Example 5 of the present invention.

[0062] Figure 34 4 is an axial aberration curve diagram of the optical lens in Example 5 of the present invention.

[0063] Figure 35 Graph showing vertical axis chromatic aberration of the optical lens in Example 5 of the present invention. DETAILED DESCRIPTION

[0064] For a better understanding of the present invention, various aspects of the present invention will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of the present invention and are not intended to limit the scope of the present invention in any way. Throughout this specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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. Furthermore, 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. Furthermore, when describing embodiments of the invention, "may" is used to mean "one or more embodiments of the invention." Furthermore, the term "exemplary" is intended to refer to an example or illustration.

[0069] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention 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.

[0070] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0071] The optical lens according to the embodiment of the present invention includes, from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, an aperture, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a filter, and a protective glass.

[0072] In some embodiments, the first lens element may have negative power to prevent excessive divergence of light on the object side, helping to control the aperture of the rear lens. The image side of the first lens element is concave, which helps to narrow the angle of incidence of outgoing light, transmitting as much light as possible to the rear end of the optical lens, thereby improving the relative illumination of the optical lens.

[0073] In some embodiments, the second lens element may have negative optical power, which can share the negative optical power of the front end of the optical lens. This helps avoid excessive light deflection caused by the overly concentrated optical power of the first lens element, thereby reducing the difficulty of correcting chromatic aberration in the optical lens. The second lens element has a concave object-side surface and a convex image-side surface. This not only reduces the impact of the field curvature generated by the second lens on the optical lens, but also effectively avoids vertical chromatic aberration caused by excessive deflection angles of light at the edge of the field of view during the transmission of light from the first lens to the second lens. This reduces the difficulty of correcting chromatic aberration in the optical lens and improves the imaging quality of the optical lens.

[0074] In some embodiments, the third lens element may have positive optical power, which helps reduce the angle of light deflection and ensures a smooth transition of light. The third lens element has a convex object-side surface and a concave image-side surface. This not only reduces the impact of field curvature generated by the third lens element on the optical lens, but also balances the spherical aberration generated by the second lens element, improving the imaging quality of the optical lens.

[0075] In some embodiments, the fourth lens element may have positive refractive power, which helps reduce the angle of light deflection and ensures a smooth transition of light. The convex object side of the fourth lens element facilitates collecting light from the periphery of the field of view, reducing the angle of light deflection at the periphery, making it easier to correct various aberrations in the optical lens and improving the imaging quality of the optical lens.

[0076] In some embodiments, the fifth lens element may have positive optical power, which helps reduce the angle of light deflection and ensures a smooth transition of light. The convex object side of the fifth lens element can reduce the energy of ghost images projected onto the image plane due to reflections in the central region, thereby improving the imaging quality of the optical lens.

[0077] In some embodiments, the sixth lens element may have positive refractive power, which helps to reduce the light deflection angle and ensure a smooth transition of light.

[0078] In some embodiments, the seventh lens element may have negative optical power, which helps increase the imaging area of the optical lens and improve the imaging quality of the optical lens. The seventh lens element may have a convex image side surface, which helps improve the relative illumination of the peripheral field of view, avoid vignetting, and enhance the imaging quality of the optical lens.

[0079] In some embodiments, the eighth lens element may have negative optical power, which helps increase the imaging area of the optical lens and improve the imaging quality of the optical lens. The eighth lens element may have a concave image-side surface, which helps suppress the angle of incidence of the edge field of view on the imaging surface, effectively transmitting more light beams to the imaging surface, and improving the imaging quality of the optical lens.

[0080] In some embodiments, the sixth lens and the seventh 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.

[0081] In some embodiments, a stop for limiting the light beam may be provided between the fourth lens and the fifth lens, which can not only reduce the generation of optical lens ghosts, but also converge the range of light emitted from the front end of the optical lens and reduce the rear port diameter of the optical lens.

[0082] In some embodiments, the aperture value FNO of the optical lens satisfies: 1.70 < FNO < 1.90. Meeting the above range can achieve a balance between depth of field and clarity of the optical lens, and meet the requirements of the optical lens for clearly acquiring long-distance information.

[0083] In some embodiments, the maximum field of view (FOV) of the optical lens satisfies the following conditions: 85° < FOV < 130°. Meeting the above range facilitates achieving wide-angle characteristics, thereby enabling the acquisition of more scene information and meeting the requirements of wide-range detection of the optical lens.

[0084] In some embodiments, the total optical length TTL of the optical lens satisfies: 32 mm < TTL < 48 mm. By meeting the above range, the total optical length of the optical lens can be controlled within a reasonable range, thereby meeting the requirements of the optical lens under different working conditions.

[0085] In some embodiments, the incident angle (CRA) of the principal ray of the optical lens's maximum field of view on the image plane satisfies the following conditions: 15° < CRA < 25°. Meeting this range allows for a larger tolerance between the CRA of the optical lens and the CRA of the chip's photosensitive element, improving the optical lens's adaptability to image sensors.

[0086] In some embodiments, the total optical length TTL and the effective focal length f of the optical lens satisfy the following relationship: TTL / f < 7.0. Meeting this range helps the optical lens achieve a balance between meeting the requirements of wide-range detection and miniaturization, and can meet the requirements of the optical lens under different working conditions.

[0087] In some embodiments, the total optical length (TTL) of the optical lens and the true image height (IH) corresponding to the maximum field of view (FOV) satisfy the following relationship: TTL / IH < 4.0. Meeting this range facilitates achieving a balance between excellent imaging quality and compact design, and can meet the requirements of optical lenses in various working conditions.

[0088] In some embodiments, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view satisfy the following conditions: 1.3 < IH / f < 1.9. Meeting this range enables both wide-angle performance, thus satisfying wide-area photography requirements, and a large image plane, thereby improving the imaging quality of the optical lens.

[0089] In some embodiments, the optical back focus (BFL) and effective focal length (f) of the optical lens satisfy the following relationship: 0.45 < BFL / f. Meeting this range helps strike a balance between good imaging quality and an optical back focus length that facilitates assembly, ensuring optical lens imaging quality while reducing the complexity of the camera module assembly process.

[0090] In some embodiments, the effective focal length f, maximum field of view (FOV), and true image height (IH) corresponding to the maximum field of view of the optical lens satisfy the following conditions: 0.45 < (IH / 2) / (f × Tan (FOV / 2)) < 0.80. Meeting these limits allows for reasonable control of optical lens distortion, facilitating subsequent restoration using software algorithms.

[0091] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens element satisfy the following conditions: -2.0 < f1 / f < -1.0. Meeting this range allows the first lens element to have an appropriate negative focal power, which helps reduce the inclination angle of the incident light, thereby effectively sharing the large object-side field of view and achieving a wider field of view angle range.

[0092] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy the following: -20.0 < f2 / f < -4.0. Meeting this range allows the second lens to have an appropriate negative focal power, which can offset the negative focal power of the front end of the optical lens. This helps avoid excessive light deflection caused by the overly concentrated focal length of the first lens, and reduces the difficulty of correcting chromatic aberration in the optical lens.

[0093] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy the following: 4.5 < f3 / f < 40.0. Meeting this range allows the third lens to have an appropriately positive focal power, balancing various aberrations of the optical lens and improving the imaging quality of the optical lens.

[0094] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens element satisfy the following relationship: 1.5 < f4 / f < 4.0. Meeting this range allows the fourth lens element to have an appropriately positive focal power, which helps converge light while reducing the angle of light deflection, ensuring a smooth transition of light and improving the imaging quality of the optical lens.

[0095] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens element satisfy the following: 1.2 < f5 / f < 5.0. Meeting this range allows the fifth lens element to have an appropriately positive focal power, which improves the ability to converge light in the peripheral field of view. It also effectively controls the overall optical length and reduces the size of the optical lens, thereby facilitating miniaturization of the optical lens element.

[0096] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens element satisfy the following conditions: 1.2 < f6 / f < 2.0. Meeting this range allows the sixth lens element to have an appropriately positive focal power, which helps improve the ability to converge light at the edge of the field of view, thereby enhancing the relative illumination of the optical lens.

[0097] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy the following: -2.0 < f7 / f < -1.0. Meeting this range allows the seventh lens to have an appropriate negative focal power, which helps increase the imaging area of the optical lens and improve the imaging quality of the optical lens.

[0098] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens element satisfy the following: -25.0 < f8 / f < -5.5. Meeting this range allows the eighth lens element to have an appropriate negative focal power, which helps increase the imaging area of the optical lens and improve the imaging quality of the optical lens.

[0099] In some embodiments, the total optical length TTL of the optical lens and the sum of the center thicknesses of the first through eighth lenses along the optical axis, ΣCT, satisfy the following condition: 0.6 < ΣCT / TTL < 0.8. Meeting this range effectively reduces the total length of the optical lens and facilitates its structural design and production process.

[0100] In order to make the system have better optical performance, multiple aspheric lenses are used in the lens, and the shape of each aspheric surface of the optical lens satisfies the following equation:

[0101]

[0102] 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 A, B, C, D, E, and F are the second-order, fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order surface coefficients, respectively.

[0103] 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.

[0104] Example 1

[0105] See also Figure 1 , shown is a schematic structural diagram of the optical lens provided in Example 1 of the present invention, which includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter G1, and a protective glass G2.

[0106] The first lens L1 has negative refractive power, and its object-side surface S1 and image-side surface S2 are both concave;

[0107] The second lens L2 has negative refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0108] The third lens L3 has positive refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave;

[0109] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex;

[0110] Aperture ST;

[0111] The fifth lens L5 has positive refractive power, and its object-side surface S9 and image-side surface S10 are both convex;

[0112] The sixth lens L6 has positive refractive power, its object-side surface S11 is concave, and its image-side surface S12 is convex;

[0113] The seventh lens L7 has negative refractive power, its object-side surface S13 is concave, and its image-side surface S14 is convex;

[0114] The eighth lens L8 has negative refractive power, and its object-side surface S15 and image-side surface S16 are both concave;

[0115] The filter G1 has an object side surface S17 and an image side surface S18 that are both flat.

[0116] The protective glass G2 has a flat object side surface S19 and an image side surface S20;

[0117] The imaging surface S21 is a plane;

[0118] The sixth lens L6 and the seventh lens L7 may be cemented together to form a cemented lens.

[0119] The relevant parameters of each lens in the optical lens in Example 1 are shown in Table 1-1.

[0120] Table 1-1

[0121]

[0122]

[0123] The surface parameters of the aspheric lens of the optical lens in Example 1 are shown in Table 1-2.

[0124] Table 1-2

[0125] Face number K A B C D E F S7 -1.26E+01 0.00E+00 3.51E-03 -2.21E-04 8.62E-06 6.38E-08 -2.02E-08 S8 -5.53E-02 0.00E+00 -3.92E-04 9.09E-05 -1.55E-05 1.23E-06 -4.47E-08 S9 -1.19E+00 0.00E+00 1.53E-04 9.27E-05 -9.07E-06 5.72E-07 -1.32E-08 S10 8.31E-03 0.00E+00 3.97E-05 2.02E-05 -5.05E-06 4.32E-07 -1.69E-08 S15 -5.00E+01 0.00E+00 -3.67E-03 -2.37E-05 -1.39E-05 1.18E-06 -6.96E-08 S16 9.52E+00 0.00E+00 -2.82E-03 -5.41E-05 2.98E-06 -1.37E-07 2.38E-09

[0126] Figure 2 The following figure shows the field curvature curve of Example 1, which shows 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 figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.02mm, demonstrating that the optical lens can excellently correct field curvature.

[0127] Figure 3The following graph shows the F-Tanθ distortion curve for Example 1, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the graph, the F-Tanθ distortion of the optical lens is uniformly controlled within ±52%, indicating that the F-Tanθ distortion of the optical lens is effectively controlled, facilitating subsequent processing using software algorithms.

[0128] Figure 4 A relative illumination curve for Example 1 is shown, showing relative illumination values at different field angles on the imaging plane. The horizontal axis represents the half field angle (unit: degrees), and the vertical axis represents relative illumination (unit: %). As can be seen from the graph, the relative illumination value of the optical lens is still greater than 80% at the maximum half field angle, indicating that the optical lens has excellent relative illumination.

[0129] Figure 5 A modulation transfer function (MTF) graph of Example 1 is shown, showing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.5 across the entire field of view. Within the range of 0 to 160 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.

[0130] Figure 6 The following graph shows the axial aberration curve for Example 1, which plots the aberration along the optical axis at the imaging plane for each wavelength. The horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. As can be seen from the graph, the offset of the axial aberration is controlled within ±5 μm, demonstrating that the optical lens is capable of excellent correction of axial aberration.

[0131] Figure 7 The vertical chromatic aberration curve for Example 1 is shown. It shows the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the figure, the vertical chromatic aberration for the longest and shortest wavelengths is controlled within ±1 μm, indicating that this optical lens can excellently correct chromatic aberration in the peripheral field of view and the secondary spectrum of the entire image plane.

[0132] Example 2

[0133] See also Figure 8, shown is a schematic structural diagram of an optical lens provided in Example 2 of the present invention, which includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter G1, and a protective glass G2.

[0134] The first lens L1 has negative refractive power, and its object-side surface S1 and image-side surface S2 are both concave;

[0135] The second lens L2 has negative refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0136] The third lens L3 has positive refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave;

[0137] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex;

[0138] Aperture ST;

[0139] The fifth lens L5 has positive refractive power, and its object-side surface S9 and image-side surface S10 are both convex;

[0140] The sixth lens L6 has positive refractive power, and its object-side surface S11 and image-side surface S12 are both convex;

[0141] The seventh lens L7 has negative power, with its object-side surface S13 being concave and its image-side surface S14 being convex. The eighth lens L8 has negative power, with its object-side surface S15 being convex and its image-side surface S16 being concave. The filter G1 has both a flat object-side surface S17 and a flat image-side surface S18.

[0142] The protective glass G2 has a flat object side surface S19 and an image side surface S20;

[0143] The imaging surface S21 is a plane;

[0144] The sixth lens L6 and the seventh lens L7 may be cemented together to form a cemented lens.

[0145] The relevant parameters of each lens in the optical lens in Example 2 are shown in Table 2-1.

[0146] Table 2-1

[0147]

[0148] The surface parameters of the aspheric lens of the optical lens in Example 2 are shown in Table 2-2.

[0149] Table 2-2

[0150] Face number K A B C D E F S3 2.36E-02 0.00E+00 3.06E-04 8.87E-06 4.51E-09 -7.20E-10 3.55E-11 S4 -2.83E-01 0.00E+00 2.24E-04 3.80E-06 -2.58E-08 5.66E-10 -4.22E-12 S9 1.18E-01 0.00E+00 1.45E-04 2.00E-07 -1.92E-08 6.81E-10 -7.24E-12 S10 1.06E+01 0.00E+00 4.57E-05 7.24E-07 -3.32E-08 1.38E-09 -2.46E-11 S15 5.00E+01 0.00E+00 -1.01E-03 4.20E-06 -2.63E-07 8.76E-09 -6.76E-11 S16 -5.00E+01 0.00E+00 -8.57E-04 3.41E-06 -1.91E-08 1.58E-09 -1.37E-11

[0151] Figure 9 The following figure shows the field curvature curves for Example 2, which plot 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 figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.04mm, demonstrating that the optical lens is capable of excellent correction of field curvature.

[0152] Figure 10 The following graph shows the F-Tanθ distortion curve for Example 2, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the graph, the F-Tanθ distortion of the optical lens is uniformly controlled within ±30%, indicating that the F-Tanθ distortion of the optical lens is effectively controlled, facilitating subsequent processing using software algorithms.

[0153] Figure 11 A relative illumination curve for Example 2 is shown, showing relative illumination values at different field angles on the imaging plane. The horizontal axis represents the half field angle (unit: degrees), and the vertical axis represents the relative illumination (unit: %). As can be seen from the graph, the relative illumination value of the optical lens is still greater than 90% at the maximum half field angle, indicating that the optical lens has excellent relative illumination.

[0154] Figure 12 A modulation transfer function (MTF) graph of Example 2 shows the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.5 across the entire field of view. Within the range of 0 to 160 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.

[0155] Figure 13 The following graph shows the axial aberration curve for Example 2, which represents the aberration on the optical axis at the imaging plane for each wavelength. The horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. As can be seen from the graph, the offset of the axial aberration is controlled within ±15 μm, indicating that the optical lens can effectively correct axial aberration.

[0156] Figure 14The vertical chromatic aberration curve for Example 2 shows the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for the longest and shortest wavelengths is controlled within ±2 μm, demonstrating that this optical lens is capable of excellently correcting chromatic aberration in the peripheral field of view and the secondary spectrum across the entire image plane.

[0157] Example 3

[0158] See also Figure 15 , shown is a schematic structural diagram of an optical lens provided in Example 3 of the present invention, which includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter G1, and a protective glass G2.

[0159] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0160] The second lens L2 has negative refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0161] The third lens L3 has positive refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave;

[0162] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex;

[0163] Aperture ST;

[0164] The fifth lens L5 has positive refractive power, and its object-side surface S9 and image-side surface S10 are both convex;

[0165] The sixth lens L6 has positive refractive power, and its object-side surface S11 and image-side surface S12 are both convex;

[0166] The seventh lens L7 has negative refractive power, its object-side surface S13 is concave, and its image-side surface S14 is convex;

[0167] The eighth lens L8 has negative refractive power, its object-side surface S15 is convex, and its image-side surface S16 is concave;

[0168] The filter G1 has an object side surface S17 and an image side surface S18 that are both flat.

[0169] The protective glass G2 has a flat object side surface S19 and an image side surface S20;

[0170] The imaging surface S21 is a plane;

[0171] The sixth lens L6 and the seventh lens L7 may be cemented together to form a cemented lens.

[0172] The relevant parameters of each lens in the optical lens in Example 3 are shown in Table 3-1.

[0173] Table 3-1

[0174]

[0175]

[0176] The surface parameters of the aspheric lens of the optical lens in Example 3 are shown in Table 3-2.

[0177] Table 3-2

[0178] Face number K A B C D E F S3 -6.58E-02 0.00E+00 2.27E-04 7.12E-06 -7.39E-08 3.62E-09 -1.45E-11 S4 8.33E-01 0.00E+00 1.83E-04 2.48E-06 -2.36E-09 2.35E-10 2.89E-12 S9 -6.35E-02 0.00E+00 1.18E-04 4.71E-08 -8.92E-08 3.66E-09 -5.73E-11 S10 7.56E+00 0.00E+00 1.81E-04 -1.33E-06 1.96E-08 2.07E-09 -7.38E-11 S15 -6.83E+00 0.00E+00 -1.03E-03 -9.12E-07 -1.99E-07 5.07E-09 -4.40E-12 S16 -4.52E+01 0.00E+00 -8.03E-04 -5.01E-06 1.64E-07 -1.32E-09 1.01E-11

[0179] Figure 16 The following is a graph of field curvature from Example 3, 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 in both the meridional and sagittal image planes is controlled within ±0.05mm, demonstrating that the optical lens is capable of excellent correction of field curvature.

[0180] Figure 17 The following graph shows the F-Tanθ distortion curve for Example 3, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the graph, the F-Tanθ distortion of the optical lens is uniformly controlled within ±26%, indicating that the F-Tanθ distortion of the optical lens is effectively controlled, facilitating subsequent processing using software algorithms.

[0181] Figure 18 A relative illumination curve for Example 3 is shown, showing relative illumination values at different viewing angles on the imaging plane. The horizontal axis represents the half-viewing angle (unit: degrees), and the vertical axis represents the relative illumination (unit: %). As can be seen from the graph, the relative illumination value of the optical lens is still greater than 80% at the maximum half-viewing angle, indicating that the optical lens has excellent relative illumination.

[0182] Figure 19A modulation transfer function (MTF) graph of Example 3 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.5 across the entire field of view. Within the range of 0 to 160 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.

[0183] Figure 20 The following graph shows the axial aberration curve for Example 3, which represents the aberration on the optical axis at the imaging plane for each wavelength. The horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. As can be seen from the graph, the offset of the axial aberration is controlled within ±15 μm, indicating that the optical lens can effectively correct axial aberration.

[0184] Figure 21 The vertical chromatic aberration curve for Example 3 is shown. It plots the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for both the longest and shortest wavelengths is controlled within ±1 μm, demonstrating that this optical lens is capable of excellently correcting chromatic aberration in the peripheral field of view and the secondary spectrum across the entire image plane.

[0185] Example 4

[0186] See also Figure 22 , shown is a schematic structural diagram of an optical lens provided in Example 4 of the present invention, which includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter G1, and a protective glass G2.

[0187] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0188] The second lens L2 has negative refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0189] The third lens L3 has positive refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave;

[0190] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex;

[0191] Aperture ST;

[0192] The fifth lens L5 has positive refractive power, and its object-side surface S9 and image-side surface S10 are both convex;

[0193] The sixth lens L6 has positive refractive power, and its object-side surface S11 and image-side surface S12 are both convex;

[0194] The seventh lens L7 has negative power, with its object-side surface S13 being concave and its image-side surface S14 being convex. The eighth lens L8 has negative power, with its object-side surface S15 being convex and its image-side surface S16 being concave. The filter G1 has both a flat object-side surface S17 and a flat image-side surface S18.

[0195] The protective glass G2 has a flat object side surface S19 and an image side surface S20;

[0196] The imaging surface S21 is a plane;

[0197] The sixth lens L6 and the seventh lens L7 may be cemented together to form a cemented lens.

[0198] The relevant parameters of each lens in the optical lens in Example 4 are shown in Table 4-1.

[0199] Table 4-1

[0200]

[0201] The surface parameters of the aspheric lens of the optical lens in Example 4 are shown in Table 4-2.

[0202] Table 4-2

[0203] Face number K A B C D E F S3 1.70E-01 0.00E+00 1.10E-04 4.29E-06 -8.90E-08 2.71E-09 -1.99E-11 S4 1.68E+00 0.00E+00 1.22E-04 1.35E-06 -9.55E-10 1.23E-10 6.62E-13 S9 -4.15E-01 0.00E+00 6.24E-05 1.71E-06 -1.26E-07 5.69E-09 -8.42E-11 S10 9.33E+01 0.00E+00 2.28E-04 -2.82E-06 1.07E-07 4.95E-10 -8.28E-11 S15 1.00E+02 0.00E+00 -9.49E-04 -6.88E-06 2.07E-08 -6.42E-09 1.57E-10 S16 -4.90E+00 0.00E+00 -7.87E-04 -2.34E-06 5.42E-08 2.21E-10 1.05E-12

[0204] Figure 23 The following graph shows the field curvature curves for Example 4, which plot 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 in both the meridional and sagittal image planes is controlled within ±0.05mm, demonstrating that the optical lens is capable of excellent correction of field curvature.

[0205] Figure 24 The following graph shows the F-Tanθ distortion curve for Example 4, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the graph, the F-Tanθ distortion of the optical lens is uniformly controlled within ±33%, indicating that the F-Tanθ distortion of the optical lens is effectively controlled, facilitating subsequent processing using software algorithms.

[0206] Figure 25A relative illumination curve for Example 4 is shown, showing relative illumination values at different viewing angles on the imaging plane. The horizontal axis represents the half-viewing angle (unit: degrees), and the vertical axis represents the relative illumination (unit: %). As can be seen from the graph, the relative illumination value of the optical lens is still greater than 80% at the maximum half-viewing angle, indicating that the optical lens has excellent relative illumination.

[0207] Figure 26 A modulation transfer function (MTF) graph of Example 4 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.5 across the entire field of view. Within the range of 0 to 160 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.

[0208] Figure 27 The following graph shows the axial aberration curve for Example 4, which represents the aberration on the optical axis at the imaging plane for each wavelength. The horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. As can be seen from the graph, the offset of the axial aberration is controlled within ±20 μm, indicating that the optical lens can effectively correct axial aberration.

[0209] Figure 28 The vertical chromatic aberration curve for Example 4 is shown. It plots the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for both the longest and shortest wavelengths is controlled within ±1 μm, demonstrating that this optical lens is capable of excellently correcting chromatic aberration in the peripheral field of view and the secondary spectrum across the entire image plane.

[0210] Example 5

[0211] See also Figure 29 , shown is a schematic structural diagram of an optical lens provided in Example 5 of the present invention, which includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter G1, and a protective glass G2.

[0212] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0213] The second lens L2 has negative refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0214] The third lens L3 has positive refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave;

[0215] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex;

[0216] Aperture ST;

[0217] The fifth lens L5 has positive refractive power, its object-side surface S9 is convex, and its image-side surface S10 is concave;

[0218] The sixth lens L6 has positive refractive power, and its object-side surface S11 and image-side surface S12 are both convex;

[0219] The seventh lens L7 has negative refractive power, its object-side surface S13 is concave, and its image-side surface S14 is convex;

[0220] The eighth lens L8 has negative refractive power, its object-side surface S15 is convex, and its image-side surface S16 is concave;

[0221] The filter G1 has an object side surface S17 and an image side surface S18 that are both flat.

[0222] The protective glass G2 has a flat object side surface S19 and an image side surface S20;

[0223] The imaging surface S21 is a plane;

[0224] The sixth lens L6 and the seventh lens L7 may be cemented together to form a cemented lens.

[0225] The relevant parameters of each lens in the optical lens in Example 5 are shown in Table 5-1.

[0226] Table 5-1

[0227]

[0228]

[0229] The surface parameters of the aspheric lens of the optical lens in Example 5 are shown in Table 5-2.

[0230] Table 5-2

[0231] Face number K A B C D E F S3 -1.72E-01 0.00E+00 2.42E-04 6.38E-06 -1.19E-07 4.95E-09 -4.19E-11 S4 7.88E-01 0.00E+00 1.90E-04 1.96E-06 -2.06E-09 2.82E-10 4.54E-13 S9 5.11E-01 0.00E+00 1.26E-04 5.68E-07 -1.04E-07 3.70E-09 -6.72E-11 S10 1.00E+02 0.00E+00 2.95E-04 -2.35E-06 1.33E-07 -2.68E-09 -7.38E-11 S15 -1.00E+02 0.00E+00 -1.05E-03 -5.95E-06 -2.00E-07 6.85E-09 -5.88E-11 S16 -8.25E+01 0.00E+00 -8.55E-04 -7.51E-06 2.45E-07 -1.74E-09 -2.68E-12

[0232] Figure 30 The following is a graph of field curvature for Example 5, 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 in both the meridional and sagittal image planes is controlled within ±0.03mm, demonstrating that the optical lens is capable of excellent correction of field curvature.

[0233] Figure 31 The following graph shows the F-Tanθ distortion curve for Example 5, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the graph, the F-Tanθ distortion of the optical lens is uniformly controlled within ±33%, indicating that the F-Tanθ distortion of the optical lens is effectively controlled, facilitating subsequent processing using software algorithms.

[0234] Figure 32 A relative illumination curve for Example 5 is shown, showing relative illumination values at different viewing angles on the imaging plane. The horizontal axis represents the half-viewing angle (unit: degrees), and the vertical axis represents the relative illumination (unit: %). As can be seen from the graph, the relative illumination value of the optical lens is still greater than 80% at the maximum half-viewing angle, indicating that the optical lens has excellent relative illumination.

[0235] Figure 33 A modulation transfer function (MTF) graph of Example 5 is shown, showing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.5 across the entire field of view. Within the range of 0 to 160 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.

[0236] Figure 34 The following graph shows the axial aberration curve for Example 5, which represents the aberration along the optical axis at the imaging plane for each wavelength. The horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. As can be seen from the graph, the offset of the axial aberration is controlled within ±20 μm, indicating that the optical lens can effectively correct axial aberration.

[0237] Figure 35 The vertical chromatic aberration curve for Example 5 is shown. It shows the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for the longest and shortest wavelengths is controlled within ±1 μm, demonstrating that this optical lens is able to excellently correct chromatic aberration in the peripheral field of view and the secondary spectrum across the entire image plane.

[0238] Please refer to Table 6, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture number FNO, true image height IH, field of view FOV of the optical lens, and the numerical values corresponding to each conditional expression in the above embodiments.

[0239] Table 6

[0240]

[0241]

[0242] In summary, the optical lens of the embodiment of the present invention achieves the advantages of large image surface, high resolution, high illumination, small size, etc. by reasonably matching the lens shape and optical power combination between each lens.

[0243] 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.

[0244] 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 eight lenses, characterized in that: Along the optical axis from the object side to the imaging surface: a first lens having negative optical power and a concave image-side surface; a second lens having negative optical power, whose object-side surface is concave and whose image-side surface is convex; The third lens has positive optical power, its object-side surface is convex and its image-side surface is concave; a fourth lens element having positive optical power and a convex object-side surface; Aperture; a fifth lens element having positive optical power and a convex object-side surface; a sixth lens element having positive refractive power and a convex image-side surface; The seventh lens element has a negative optical power, its object-side surface is concave and its image-side surface is convex; an eighth lens element having negative optical power and a concave image-side surface; The total optical length TTL and the effective focal length f of the optical lens satisfy the following conditions: TTL / f<7.

0.

2. The optical lens according to claim 1, wherein: The total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle satisfy the following: TTL / IH<4.

0.

3. The optical lens according to claim 1, wherein: The optical back focus BFL of the optical lens and the effective focal length f satisfy the following: 0.45<BFL / f.

4. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy the following: -2.0<f1 / f<-1.

0.

5. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy the following: -20.0<f2 / f<-4.

0.

6. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy the following: 4.5<f3 / f<40.

0.

7. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy the following: 1.5<f4 / f<4.

0.

8. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy the following: 1.2<f5 / f<5.

0.

9. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy the following: -25.0<f8 / f<-5.

5.

10. The optical lens according to claim 1, wherein: The total optical length TTL of the optical lens and the sum ΣCT of the center thicknesses of the first to sixth lenses along the optical axis respectively satisfy the following: 0.6<ΣCT / TTL<0.8.

Images