Optical lens

Abstract

The present invention provides an optical lens having a total of six 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 focal power, whose object side surface is convex and whose image side surface is concave; a second lens having negative focal power, whose object side surface and image side surface are both concave; an aperture; a third lens having positive focal power, whose object side surface and image side surface are both convex; a fourth lens having positive focal power, whose object side surface and image side surface are both convex; a fifth lens having negative focal power, whose object side surface is concave and whose image side surface is convex; a sixth lens having positive focal power, whose object side surface and image side surface are both convex; a true image height IH corresponding to the maximum field angle of the optical lens and a true image height IH corresponding to the half field angle of the optical lens θ Satisfies: 0.65<IH θ / IH<0.75.

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] Compared with ordinary optical lenses, the on-board lenses in driving assistance systems have special requirements. For example, on-board camera lenses require the front aperture to be as small as possible, with strong light transmission capability and the ability to adapt to changes in brightness and darkness in the external environment. At the same time, they are required to have high image clarity, be able to effectively distinguish details of the external environment, and have good thermal stability so that the lens has good resolution at high and low temperatures to meet the special requirements of autonomous driving. 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, comprising six 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, wherein the object-side surface is convex and the image-side surface is concave;

[0008] a second lens having negative optical power, wherein both the object-side surface and the image-side surface are concave;

[0009] Aperture;

[0010] The third lens has positive optical power and its object-side and image-side surfaces are both convex;

[0011] The fourth lens element has positive refractive power, and both the object-side surface and the image-side surface are convex;

[0012] a fifth lens element having negative optical power, whose object-side surface is concave and whose image-side surface is convex;

[0013] a sixth lens element having positive refractive power, wherein both the object-side surface and the image-side surface are convex;

[0014] The real image height IH corresponding to the maximum field angle of the optical lens and the real image height IH corresponding to the half field angle θ Satisfies: 0.65<IH θ / IH<0.75.

[0015] Preferably, the effective working aperture D1 of the first lens objective side is equal to the effective working aperture D1 of the first lens objective side half field angle θ. θ Satisfaction: 0.75<D θ / D1<0.85.

[0016] Preferably, the total optical length TTL and the effective focal length f of the optical lens satisfy: 5.0<TTL / f<6.0.

[0017] Preferably, the optical back focus BFL of the optical lens and the effective focal length f satisfy: 0.65<BFL / f.

[0018] Preferably, the entrance pupil diameter EPD of the optical lens and the real image height IH corresponding to the maximum field angle satisfy: 1.8<IH / EPD<2.2.

[0019] Preferably, the effective focal length f, the maximum field of view FOV and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.35<(IH / 2) / (f×Tan(FOV / 2))<0.45.

[0020] Preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.0<f1 / f<-1.3.

[0021] Preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -5.0<f2 / f<-2.0.

[0022] Preferably, the combined focal length f of the first lens and the second lens is 12 The combined focal length f of the third lens to the sixth lens 36 Satisfy: 0.6<f 12 / f 36 <0.9.

[0023] 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: 0.50<ΣCT / TTL<0.70.

[0024] Compared with the prior art, the beneficial effects of the present invention are: by reasonably matching the lens shape and optical focal length combination between each lens, the advantages of large field of view, large aperture, high definition and excellent thermal stability are achieved.

[0025] 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

[0026] 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:

[0027] Figure 1 Schematic diagram of the structure of the optical lens of Example 1 of the present invention;

[0028] Figure 2 is a field curvature curve diagram of the optical lens in Example 1 of the present invention;

[0029] Figure 3 : is a graph showing the F-tanθ distortion curve of the optical lens in Example 1 of the present invention;

[0030] Figure 4 is a relative illumination curve diagram of the optical lens in Example 1 of the present invention;

[0031] Figure 5 : is an MTF curve diagram of the optical lens in Example 1 of the present invention;

[0032] Figure 6 : is an axial aberration curve diagram of the optical lens in Example 1 of the present invention;

[0033] Figure 7 Graph showing vertical axis chromatic aberration of the optical lens in Example 1 of the present invention;

[0034] Figure 8 Schematic diagram of actual imaging positions of the equally spaced field of view of the optical lens in Example 1 of the present invention;

[0035] Figure 9 Schematic diagram of the structure of an optical lens according to embodiment 2 of the present invention;

[0036] Figure 10 is a field curvature curve diagram of the optical lens in Example 2 of the present invention;

[0037] Figure 11 : is a graph showing the F-tanθ distortion curve of the optical lens in Example 2 of the present invention;

[0038] Figure 12 is a relative illumination curve diagram of the optical lens in Example 2 of the present invention;

[0039] Figure 13 : is an MTF curve diagram of the optical lens in Example 2 of the present invention;

[0040] Figure 14 : is an axial aberration curve diagram of the optical lens in Example 2 of the present invention;

[0041] Figure 15 Graph showing vertical axis chromatic aberration of the optical lens in Example 2 of the present invention;

[0042] Figure 16 Schematic diagram of actual imaging positions of the equally spaced field of view of the optical lens in Example 2 of the present invention;

[0043] Figure 17 Schematic diagram of the structure of an optical lens according to embodiment 3 of the present invention;

[0044] Figure 18 is a field curvature curve diagram of the optical lens in Example 3 of the present invention;

[0045] Figure 19 : is a graph showing the F-tanθ distortion curve of the optical lens in Example 3 of the present invention;

[0046] Figure 20 is a relative illumination curve diagram of the optical lens in Example 3 of the present invention;

[0047] Figure 21 : is an MTF curve diagram of the optical lens in Example 3 of the present invention;

[0048] Figure 22 : is an axial aberration curve diagram of the optical lens in Example 3 of the present invention;

[0049] Figure 23 Graph showing vertical axis chromatic aberration of the optical lens in Example 3 of the present invention;

[0050] Figure 24 Schematic diagram of actual imaging positions of the equally spaced field of view of the optical lens of Example 3 of the present invention. DETAILED DESCRIPTION

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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, an aperture, a third lens, a fourth lens, a fifth lens, a sixth lens, a filter, and a protective glass.

[0059] In some embodiments, the first lens may have negative optical power, which helps reduce the inclination angle of the incident light, thereby effectively sharing the large object-side field of view. The object-side surface of the first lens is convex, and the image-side surface is concave, which helps to obtain a larger field of view angle range. In addition, in practical applications, considering the outdoor installation and use environment of automotive application lenses, the lens may be exposed to inclement weather such as rain and snow. Setting the first lens in a meniscus shape with the convex surface facing the object side can help water droplets slide off, reducing the impact on the lens imaging.

[0060] 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, reducing the difficulty of correcting chromatic aberration in the optical lens. Both the object and image side surfaces of the second lens element are concave, which helps improve the ability to collect light from the edge of the field of view while reducing the working aperture of the second lens element, thereby facilitating the miniaturization of the rear end of the optical lens. Furthermore, this can reduce the coma generated by the second lens element itself, making it easier to correct subsequent lens aberrations and improving the imaging quality of the optical lens element.

[0061] In some embodiments, the third lens element may have positive optical power, which helps converge light while reducing light deflection angles and ensuring a smooth transition. Both the object and image side surfaces of the third lens element are convex. This not only allows light reflected from the object side of the third lens to focus behind the image side, effectively improving design ghosting in the optical lens, but also reduces spherical aberration and coma generated by the third lens element itself, improving the imaging quality of the optical lens.

[0062] In some embodiments, the fourth lens element can have positive optical power, which helps converge light while reducing light deflection angles and ensuring a smooth transition. Both the object and image side surfaces of the fourth lens element are convex, which can reduce spherical aberration and coma generated by the fourth lens element itself, thereby improving the imaging quality of the optical lens.

[0063] In some embodiments, the fifth 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 fifth lens element has a concave object-side surface and a convex image-side surface, which can reduce the deflection angle of the outgoing light, avoid excessive light divergence and the generation of various high-order aberrations, and improve the imaging quality of the optical lens.

[0064] In some embodiments, the sixth lens element may have positive refractive power, which helps suppress the angle of incidence of the peripheral field of view on the imaging plane, effectively transmitting more light beams to the imaging plane, and improving the imaging quality of the optical lens. The sixth lens element may have a convex object side surface, which helps improve the relative illumination of the peripheral field of view, avoid the generation of vignetting, and enhance the imaging quality of the optical lens.

[0065] 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.

[0066] In some embodiments, an aperture for limiting the light beam may be provided between the second lens and the third lens. The aperture may be provided near the object side of the third lens, which can reduce the generation of optical lens ghosts and is beneficial for focusing the light entering the optical system and reducing the rear port diameter of the optical lens.

[0067] In some embodiments, the aperture value FNO of the optical lens satisfies: FNO<1.55. Meeting the above range is conducive to achieving a large aperture characteristic and ensuring image clarity in low-light environments or at night.

[0068] In some embodiments, the maximum field of view (FOV) of the optical lens satisfies the following conditions: 120°≤FOV. 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.

[0069] In some embodiments, the incident angle CRA of the principal ray of the maximum field angle of the optical lens on the image plane satisfies: CRA < 5°. Meeting the above range enables the optical lens to match a small-angle chip photosensitive element.

[0070] In some embodiments, the total optical length TTL and the effective focal length f of the optical lens satisfy the following relationship: 5.0 < TTL / f < 6.0. Meeting the above range can effectively limit the length of the lens, which is conducive to miniaturization of the optical lens.

[0071] 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 relationship: 1.3 < IH / f. Meeting this range enables both wide-angle performance, thus meeting the requirements of wide-range detection, and a large image plane, thereby improving the imaging quality of the optical system.

[0072] In some embodiments, the optical back focus (BFL) and effective focal length (f) of the optical lens satisfy the following relationship: 0.65 < 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.

[0073] In some embodiments, the optical lens' entrance pupil diameter (EPD) and the true image height (IH) corresponding to the maximum field of view satisfy the following relationship: 1.8 < IH / EPD < 2.2. Meeting this range increases the width of the light beam entering the optical lens, improving brightness at the image plane and preventing vignetting, while also increasing the imaging area of the optical lens.

[0074] In some embodiments, the effective working aperture D1 of the first lens objective side is equal to the effective working aperture D1 of the first lens objective side half field angle θ. θ Satisfaction: 0.75<D θ / D1<0.85. When this range is met, light rays of different field angles are adjusted to varying degrees after entering the first lens, so that the central field of view has a much higher proportion of light rays on the object side of the first lens than the peripheral field of view. In other words, by adjusting the height of light rays from different fields of view on the object side of the first lens, it is easier to control the height at which different fields of view are focused on the imaging surface.

[0075] In some embodiments, the real image height IH corresponding to the maximum field angle of the optical lens is equal to the real image height IH corresponding to the half field angle of the optical lens. θ Satisfies: 0.65<IH θ / IH<0.75. Meeting the above range can increase the proportion of the central field of view imaging range in the entire imaging range. The larger the imaging range, the more pixels occupy the corresponding chip surface, thereby obtaining more detailed information.

[0076] 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: 0.35 < (IH / 2) / (f × Tan (FOV / 2)) < 0.45. Meeting these limits increases distortion at the edges of the optical lens' imaging surface, minimizing distortion in the center of the imaging surface, thereby improving imaging quality in the central region.

[0077] 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 < -1.3. 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.

[0078] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy the following: -5.0 < f2 / f < -2.0. 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, thereby helping to avoid excessive light deflection caused by the overly concentrated focal length of the first lens.

[0079] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens element satisfy the following relationship: 1.2 < f3 / f < 1.8. Meeting this range allows the third lens element to have an appropriately positive focal power, facilitating a smooth transition of light, while also correcting various aberrations of the optical lens and improving imaging quality.

[0080] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.0 < f4 / f < 1.5. Satisfying the above range can make the fourth lens have an appropriate positive optical power, which is beneficial to the smooth transition of light rays, and at the same time correct various aberrations of the optical lens, improving the imaging quality of the optical lens.

[0081] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -2.5 < f5 / f < -1.5. Satisfying the above range can make the fifth lens have an appropriate negative optical power, which is beneficial to increasing the imaging area of the optical lens, and at the same time correct various aberrations of the optical lens, improving the imaging quality of the optical lens; at the same time, by combining with the fourth lens to form a cemented lens, it can balance the chromatic aberration of the optical lens and improve the imaging quality of the optical lens.

[0082] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 2.1 < f6 / f < 2.7. Satisfying the above range can make the sixth lens have an appropriate positive optical power, which is beneficial to suppressing the angle of the marginal field incident on the imaging surface, effectively transmitting more light beams to the imaging surface, and improving the imaging quality of the optical lens.

[0083] In some embodiments, the combined focal length f of the first lens and the second lens 12 and the combined focal length f of the third lens to the sixth lens 36 satisfy: 0.6 < f 12 / f 36 < 0.9. Satisfying the above range can reduce the difficulty of correcting various aberrations of the lens group behind the diaphragm of the optical lens, and at the same time is beneficial to the improvement of the temperature drift problem of the optical lens, improving the imaging quality of the optical lens.

[0084] In some embodiments, the object-side curvature radius R1 and the image-side curvature radius R2 of the first lens and the central thickness CT1 of the first lens satisfy: 0.9 < R1 / (R2 + CT1) < 1.1. Satisfying the above range can make the light distribution passing through the first lens more uniform, which is beneficial to reasonably distribute the light deflection angle at the front end of the wide-angle lens, making the whole system have wide-angle characteristics.

[0085] In some embodiments, the overall optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the sixth lens along the optical axis respectively satisfy: 0.50 < ∑CT / TTL < 0.70. Satisfying the above range can increase the proportion of the lens in the optical lens and can improve...

[0086] To make the system have better optical performance, multiple aspherical lenses are used in the lens. The shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0087]

[0088] 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.

[0089] 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.

[0090] Example 1

[0091] 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, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a filter G1, and a protective glass G2.

[0092] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0093] The second lens L2 has negative refractive power, and its object-side surface S3 and image-side surface S4 are both concave;

[0094] Aperture ST;

[0095] The third lens L3 has positive refractive power, and its object-side surface S5 and image-side surface S6 are both convex;

[0096] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex;

[0097] The fifth lens L5 has negative refractive power, its object-side surface S9 is concave, and its image-side surface S10 is convex;

[0098] The sixth lens L6 has positive refractive power, and its object-side surface S11 and image-side surface S12 are both convex;

[0099] The filter G1 has an object side surface S13 and an image side surface S14 that are both flat surfaces;

[0100] The protective glass G2 has a flat object side surface S15 and an image side surface S16;

[0101] The imaging surface S17 is a plane.

[0102] The fourth lens L4 and the fifth lens L5 may be cemented together to form a cemented lens.

[0103] The relevant parameters of each lens in the optical lens in Example 1 are shown in Table 1-1.

[0104] Table 1-1

[0105]

[0106]

[0107] The surface parameters of the aspheric lens of the optical lens in Example 1 are shown in Table 1-2.

[0108] Table 1-2

[0109] Face number K A B C D E F S1 -3.30E+00 0.00E+00 2.61E-03 -5.06E-04 1.29E-05 4.94E-07 -2.30E-08 S2 -2.28E+00 0.00E+00 2.46E-02 -6.30E-03 8.36E-04 -5.30E-05 7.65E-07

[0110] 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: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.04mm, indicating that the optical lens can effectively correct field curvature.

[0111] Figure 3 The 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 surface. The horizontal axis represents 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 controlled at approximately 65%, which is significantly greater than that of conventional lenses of the same type. This is to achieve a clearer image in the center of the imaging surface without controlling the distortion at the edges.

[0112] 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 the relative illumination (unit: %). As can be seen from the graph, the relative illumination value of the optical lens is still greater than 70% at the maximum half field angle, indicating that the optical lens has excellent relative illumination.

[0113] Figure 5A 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 0.4 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 edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0114] Figure 6 The following graph shows the axial aberration curve for Example 1, 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 is able to effectively correct axial aberration.

[0115] Figure 7 The vertical chromatic aberration curve for Example 1 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 ±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.

[0116] Figure 8 The figure shows the actual imaging positions of the equally spaced fields of view in Example 1. The horizontal axis represents the horizontal image plane position (unit: mm), and the vertical axis represents the vertical image plane position (unit: mm). As can be seen from the figure, the imaging range of the central field of view accounts for a significantly larger proportion of the entire imaging range, indicating that the lens has better imaging effect in the central area.

[0117] Example 2

[0118] See also Figure 9 , shown is a schematic structural diagram of the 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, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a filter G1, and a protective glass G2.

[0119] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0120] The second lens L2 has negative refractive power, and its object-side surface S3 and image-side surface S4 are both concave;

[0121] Aperture ST;

[0122] The third lens L3 has positive refractive power, and its object-side surface S5 and image-side surface S6 are both convex;

[0123] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex;

[0124] The fifth lens L5 has negative refractive power, its object-side surface S9 is concave, and its image-side surface S10 is convex;

[0125] The sixth lens L6 has positive refractive power, its object-side surface S11 is convex, and its image-side surface S12 is concave;

[0126] The filter G1 has an object side surface S13 and an image side surface S14 that are both flat surfaces;

[0127] The protective glass G2 has a flat object side surface S15 and an image side surface S16;

[0128] The imaging surface S17 is a plane.

[0129] The fourth lens L4 and the fifth lens L5 may be cemented together to form a cemented lens.

[0130] The relevant parameters of each lens in the optical lens in Example 2 are shown in Table 2-1.

[0131] Table 2-1

[0132]

[0133] The surface parameters of the aspheric lens of the optical lens in Example 2 are shown in Table 2-2.

[0134] Table 2-2

[0135] Face number K A B C D E F S1 -4.19E+00 0.00E+00 3.76E-03 -6.98E-04 3.19E-05 -4.16E-07 -4.82E-09 S2 -2.44E+00 0.00E+00 2.92E-02 -7.51E-03 1.07E-03 -7.55E-05 2.15E-06

[0136] Figure 10 The following figure shows the field curvature curve of Example 2, 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 ±0.03mm, indicating that the optical lens can effectively correct field curvature.

[0137] Figure 11The F-tanθ distortion curve for Example 2 is shown, showing the F-tanθ distortion of light of different wavelengths at different image heights on the imaging surface. The horizontal axis represents 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 controlled at approximately 65%, which is significantly greater than that of conventional lenses of the same type. This is to achieve a clearer image in the center of the imaging surface without controlling the distortion at the edges.

[0138] Figure 12 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 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.

[0139] Figure 13 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 0.4 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 edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0140] Figure 14 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 ±20 μm, indicating that the optical lens is able to effectively correct axial aberration.

[0141] Figure 15 The 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.

[0142] Figure 16The figure shows the actual imaging positions of the equally spaced fields of view in Example 2. The horizontal axis represents the horizontal image plane position (unit: mm), and the vertical axis represents the vertical image plane position (unit: mm). As can be seen from the figure, the imaging range of the central field of view accounts for a significantly larger proportion of the entire imaging range, indicating that the lens has better imaging effect in the central area.

[0143] Example 3

[0144] See also Figure 17 , 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, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a filter G1, and a protective glass G2.

[0145] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0146] The second lens L2 has negative refractive power, and its object-side surface S3 and image-side surface S4 are both concave;

[0147] Aperture ST;

[0148] The third lens L3 has positive refractive power, and its object-side surface S5 and image-side surface S6 are both convex;

[0149] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex;

[0150] The fifth lens L5 has negative refractive power, its object-side surface S9 is concave, and its image-side surface S10 is convex;

[0151] The sixth lens L6 has positive refractive power, and its object-side surface S11 and image-side surface S12 are both convex;

[0152] The filter G1 has an object side surface S13 and an image side surface S14 that are both flat surfaces;

[0153] The protective glass G2 has a flat object side surface S15 and an image side surface S16;

[0154] The imaging surface S17 is a plane.

[0155] The fourth lens L4 and the fifth lens L5 may be cemented together to form a cemented lens.

[0156] The relevant parameters of each lens in the optical lens in Example 3 are shown in Table 3-1.

[0157] Table 3-1

[0158]

[0159] The surface parameters of the aspheric lens of the optical lens in Example 3 are shown in Table 3-2.

[0160] Table 3-2

[0161] Face number K A B C D E F S1 -3.16E+00 0.00E+00 2.92E-03 -3.26E-04 2.84E-06 4.15E-07 -1.08E-08 S2 -9.35E-01 0.00E+00 -1.24E-03 -8.66E-04 -7.50E-05 2.65E-05 -1.50E-06

[0162] Figure 18 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 ±0.02mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0163] Figure 19 The F-tanθ distortion curve for Example 3 is shown, showing the F-tanθ distortion of light of different wavelengths at different image heights on the imaging surface. The horizontal axis represents 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 controlled at approximately 65%, which is significantly greater than that of conventional lenses of the same type. This is to achieve a clearer image in the center of the imaging surface without controlling the distortion at the edges.

[0164] Figure 20 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.

[0165] Figure 21 A 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 120 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.

[0166] Figure 22 The following graph shows the axial aberration curve for Example 3, 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 ±10 μm, demonstrating that the optical lens is capable of excellent correction of axial aberration.

[0167] Figure 23 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 ±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.

[0168] Figure 24 The figure shows the actual imaging positions of the equally spaced fields of view in Example 3. The horizontal axis represents the horizontal image plane position (unit: mm), and the vertical axis represents the vertical image plane position (unit: mm). As can be seen from the figure, the imaging range of the central field of view accounts for a significantly larger proportion of the entire imaging range, indicating that the lens has better imaging effect in the central area.

[0169] Please refer to Table 4, 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.

[0170] Table 4

[0171] Parameters and Conditionals Example 1 Example 2 Example 3 f(mm) 4.40 4.40 4.31 TTL(mm) 24.00 24.00 24.00 FNO 1.53 1.53 1.52 IH(mm) 5.76 5.76 5.76 EPD(mm) 2.88 2.87 2.84 FOV(°) 120 120 120 CRA(°) 3.19 3.25 3.64 TTL / f 5.45 5.46 5.80 IH / f 1.31 1.31 1.34 BFL / f 0.77 0.76 0.70 IH / EPD 2.00 2.01 2.03 <![CDATA[D θ / D1]]> 0.81 0.79 0.79 <![CDATA[IH θ / IH]]> 0.68 0.68 0.67 (IH / 2) / (f×tan(FOV / 2)) 0.38 0.38 0.39 <![CDATA[f1 / f]]> -1.64 -1.52 -1.80 <![CDATA[f2 / f]]> -2.42 -4.31 -3.38 <![CDATA[f3 / f]]> 1.46 1.49 1.61 <![CDATA[f4 / f]]> 1.35 1.27 1.39 <![CDATA[f5 / f]]> -2.25 -1.60 -1.94 <![CDATA[f6 / f]]> 2.39 2.39 2.53 <![CDATA[f 12 / f 36 ]]> 0.62 0.81 0.84 <![CDATA[R1 / (R2+CT1)]]> 1.01 1.04 0.97 ∑CT / TTL 0.59 0.63 0.67

[0172] In summary, the optical lens of the embodiment of the present invention achieves the advantages of a large field of view, a large aperture, high definition and excellent thermal stability by reasonably matching the lens shapes and optical power combinations between the lenses.

[0173] 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.

[0174] 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 six lenses, characterized in that: Along the optical axis from the object side to the imaging surface: a first lens having negative optical power, wherein the object-side surface is convex and the image-side surface is concave; a second lens having negative optical power, wherein both the object-side surface and the image-side surface are concave; Aperture; The third lens has positive optical power and its object-side and image-side surfaces are both convex; The fourth lens element has positive refractive power, and both the object-side surface and the image-side surface are convex; a fifth lens element having negative optical power, whose object-side surface is concave and whose image-side surface is convex; a sixth lens element having positive refractive power, wherein both the object-side surface and the image-side surface are convex; The real image height IH corresponding to the maximum field angle of the optical lens and the real image height IH corresponding to the half field angle θ Satisfies: 0.65<IH θ / IH<0.

75.

2. The optical lens according to claim 1, wherein: The effective working aperture D1 of the first lens objective side is equal to the effective working aperture D of the first lens objective side half field angle θ. θ Satisfaction: 0.75<D θ / D1<0.

85.

3. The optical lens according to claim 1, wherein: The total optical length TTL and the effective focal length f of the optical lens satisfy the following conditions: 5.0<TTL / f<6.

0.

4. 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: 0.65<BFL / f.

5. The optical lens according to claim 1, wherein: The entrance pupil diameter EPD of the optical lens and the real image height IH corresponding to the maximum field angle satisfy the following: 1.8<IH / EPD<2.

2.

6. The optical lens according to claim 1, wherein: The effective focal length f, the maximum field of view FOV and the real image height IH corresponding to the maximum field of view of the optical lens satisfy the following conditions: 0.35<(IH / 2) / (f×Tan(FOV / 2))<0.

45.

7. 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 relationship: -2.0<f1 / f<-1.

3.

8. 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: -5.0<f2 / f<-2.

0.

9. The optical lens according to claim 1, wherein: The combined focal length f of the first lens and the second lens 12 The combined focal length f of the third lens to the sixth lens 36 Satisfy: 0.6<f 12 / f 36 <0.

9.

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: 0.50<ΣCT / TTL<0.70.

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