Optical lens

Abstract

The present invention provides an optical lens, which consists of seven lenses in total. Along the optical axis from the object side to the imaging surface, it successively includes: a first lens with a negative optical power, whose object side is convex and image side is concave; a second lens with a negative optical power, whose image side is concave; a third lens with a negative optical power, whose object side is convex and image side is concave; a fourth lens with a positive optical power, whose object side and image side are both convex; a fifth lens with a negative optical power, whose object side is convex and image side is concave; a sixth lens with a positive optical power, whose object side is convex; a seventh lens with a positive optical power; the effective focal length f of the optical lens and the central thickness CT3 of the third lens along the optical axis satisfy: 2.5 < CT3 / f < 4.5. The optical lens provided by the present invention improves the field curvature of the optical lens, reduces aberration, and improves the imaging quality of the optical lens through the reasonable configuration of each lens surface type and the reasonable combination of optical powers.

Description

Technical Field

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

[0002] As people's requirements for driving experience continue to increase, automotive optical lenses are increasingly used in intelligent driving, and the status of automotive optical lenses in the automotive-related industries continues to improve.

[0003] The surround-view system utilizes multiple cameras positioned around the vehicle to provide comprehensive coverage. The system integrates these cameras' perspectives into a 360-degree bird's-eye view of the surrounding area, which is then displayed on the center console screen. This allows the driver to clearly identify obstacles and their relative position and distance, helping them to park easily. This intuitive system eliminates blind spots, allowing drivers to maneuver the vehicle with ease when maneuvering into parking spaces or navigating complex road conditions, effectively reducing the risk of scrapes, collisions, and falls.

[0004] At present, surround-view camera lenses generally use wide-angle lenses, which have problems such as large aberrations, large field curvature, and poor image quality, making it difficult to meet user needs. Summary of the Invention

[0005] In view of the above problems, an object of the present invention is to provide an optical lens having the advantage of excellent imaging quality.

[0006] The present invention provides an optical lens, comprising seven lenses, which include the following lenses in order from the object side to the imaging surface along the optical axis:

[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 element having negative optical power and a concave image-side surface;

[0009] The third lens has a negative optical power, with a convex object-side surface and a concave image-side surface;

[0010] The fourth lens element has positive refractive power, and both the object-side surface and the image-side surface are convex;

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

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

[0013] a seventh lens having positive optical power;

[0014] The effective focal length f of the optical lens and the center thickness CT3 of the third lens along the optical axis satisfy: 2.5 <CT3 / f<4.5。

[0015] Further preferably, the total optical length TTL and the effective focal length f of the optical lens satisfy: 11.0 <TTL / f<13.5。

[0016] Further preferably, the effective focal length f of the optical lens, the arc θ of the maximum half field angle, and the real image height IH corresponding to the maximum field angle satisfy: 0.9<(IH / 2) / (f×θ)<1.0.

[0017] Further preferably, the maximum field of view FOV and aperture value FNO of the optical lens meet the following requirements: 100° <FOV / FNO<140°。

[0018] Further preferably, a curvature radius R5 of the object side surface of the third lens and a curvature radius R6 of the image side surface of the third lens satisfy: 0.1<(R5-R6) / (R5+R6)<0.8.

[0019] Further preferably, the total optical length TTL of the optical lens and the sum ΣCT of the center thicknesses of the first to seventh lenses along the optical axis respectively satisfy: 0.5<ΣCT / TTL<0.7.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -4.5 <f1 / f<-3.0。

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -4.5 <f2 / f<-2.5。

[0022] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -68.0 <f3 / f<-3.0。

[0023] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.5 <f4 / f<3.5。

[0024] The optical lens provided by the present invention improves the field curvature of the optical lens, reduces aberrations, and improves the imaging quality of the optical lens through the reasonable configuration of the surface shapes of each lens and the reasonable matching of the optical focal length. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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:

[0026] Figure 1 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

[0027] Figure 2Graph showing the field curvature of the optical lens in Example 1 of the present invention.

[0028] Figure 3 : is the F-Theta distortion curve of the optical lens in Example 1 of the present invention.

[0029] Figure 4 This is a relative illumination curve diagram of the optical lens in Example 1 of the present invention.

[0030] Figure 5 This is the MTF curve of the optical lens in Example 1 of the present invention.

[0031] Figure 6 1 is an axial aberration curve diagram of the optical lens in Example 1 of the present invention.

[0032] Figure 7 Graph showing the vertical axis chromatic aberration of the optical lens in Example 1 of the present invention.

[0033] Figure 8 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0034] Figure 9 Graph showing the field curvature of the optical lens in Example 2 of the present invention.

[0035] Figure 10 : is the F-Theta distortion curve of the optical lens in Example 2 of the present invention.

[0036] Figure 11 This is a relative illumination curve diagram of the optical lens in Example 2 of the present invention.

[0037] Figure 12 This is an MTF curve diagram of the optical lens in Example 2 of the present invention.

[0038] Figure 13 2 is an axial aberration curve diagram of the optical lens in Example 2 of the present invention.

[0039] Figure 14 Graph showing vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0040] Figure 15 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0041] Figure 16 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0042] Figure 17 : This is the F-Theta distortion curve of the optical lens in Example 3 of the present invention.

[0043] Figure 18 This is a relative illumination curve diagram of the optical lens in Example 3 of the present invention.

[0044] Figure 19 This is the MTF curve of the optical lens in Example 3 of the present invention.

[0045] Figure 20 4 is an axial aberration curve diagram of the optical lens in Example 3 of the present invention.

[0046] Figure 21 Graph showing vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0047] Figure 22 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0048] Figure 23 4 is a field curvature curve diagram of the optical lens in Example 4 of the present invention.

[0049] Figure 24 : is the F-Theta distortion curve of the optical lens in Example 4 of the present invention.

[0050] Figure 25 This is a relative illumination curve diagram of the optical lens in Example 4 of the present invention.

[0051] Figure 26 This is the MTF curve of the optical lens in Example 4 of the present invention.

[0052] Figure 27 4 is an axial aberration curve diagram of the optical lens in Example 4 of the present invention.

[0053] Figure 28 Graph showing vertical axis chromatic aberration of the optical lens in Example 4 of the present invention.

[0054] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0055] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of embodiments of the present application and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] It should also be understood that the terms "comprises," "including," "having," "includes," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application." And, the term "exemplary" is intended to refer to an example or illustration.

[0060] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0061] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0062] The optical lens of the embodiment of the present invention includes, along the optical axis from the object side to the imaging surface, a first lens, a second lens, a third lens, a fourth lens, an aperture, a fifth lens, a sixth lens, a seventh lens, a filter and a protective glass.

[0063] In some embodiments, the first lens may have a negative optical power, which is beneficial to reducing 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 is beneficial to collecting the marginal field of view light into the rear optical lens as much as possible and achieving large-angle light collection.

[0064] In some embodiments, the second lens may have a negative optical power, and its image side surface is concave, which can share the negative optical power at the front end of the lens, thereby being beneficial to reducing the excessive light deflection caused by the over-concentration of the optical power of the first lens and reducing the difficulty of chromatic aberration correction of the optical lens.

[0065] In some embodiments, the third lens may have a negative optical power, its object side surface is convex, and the image side surface is concave, which is beneficial to reducing the light deflection angle and enabling the light to transition smoothly, thereby improving the imaging quality of the optical lens.

[0066] In some embodiments, the fourth lens may have a positive optical power, which is beneficial to improving the light converging ability of the optical lens. Both the object side surface and the image side surface of the fourth lens are convex, which is beneficial to balancing various aberrations generated by the optical lens and improving the imaging quality of the optical lens.

[0067] In some embodiments, the fifth lens may have a negative optical power, which is beneficial to increasing the imaging area of the optical lens and improving the imaging quality of the optical lens. The object side surface of the fifth lens is convex, and the image side surface is concave, which can optimize the chromatic aberration of the optical lens and improve the imaging quality of the optical lens.

[0068] In some embodiments, the sixth lens may have a positive optical power, its object side surface is convex, which is beneficial to improving the light converging ability of the optical lens, balancing various aberrations generated by the optical lens, and improving the imaging quality of the optical lens.

[0069] In some embodiments, the seventh lens may have a positive optical power, which is beneficial to suppressing the angle of incidence of the marginal 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.

[0070] In some embodiments, the effective focal length f of the optical lens and the central thickness CT3 of the third lens along the optical axis satisfy: 2.5 < CT3 / f < 4.5. Meeting the above range, by setting a relatively thick third lens, the field curvature of the ultra-wide-angle lens can be improved, the difficulty of lens aberration optimization can be reduced, and thus the lens imaging quality can be improved.

[0071] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f satisfy: 11.0 < TTL / f < 13.5. Meeting the above range ensures that there is enough space to adjust the lens structure and optimize the imaging effect.

[0072] In some embodiments, the effective focal length f of the optical lens, the radian θ of the maximum half field angle, and the true image height IH corresponding to the maximum field angle satisfy: 0.9 < (IH / 2) / (f×θ) < 1.0. Meeting the above range indicates that the F-Theta distortion of the optical lens is well controlled, improving the resolution of the optical lens.

[0073] In some embodiments, the maximum field angle FOV of the optical lens and the aperture value FNO satisfy: 100° < FOV / FNO < 140°. Meeting the above range is beneficial to expanding the field angle of the optical lens and increasing the aperture of the optical lens, facilitating the optical lens to obtain more scene information and meeting the requirements of large-range detection. The realization of the large-aperture characteristic is beneficial to improving the problem of rapid decline in relative brightness in the edge field of view, and thus is also beneficial to obtaining more scene information.

[0074] In some embodiments, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field angle satisfy: 3.3 < IH / f < 3.7. Meeting the above range is beneficial for the optical lens to balance between the field angle size and the F-Theta distortion size, improving the imaging quality of the optical lens.

[0075] In some embodiments, the object-side curvature radius R5 of the third lens and the image-side curvature radius R6 of the third lens satisfy: 0.1 < (R5 - R6) / (R5 + R6) < 0.8. Meeting the above range can reduce the difficulty of lens aberration optimization, thereby improving the lens imaging quality.

[0076] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis satisfy: 0.5 < ∑CT / TTL < 0.7. Meeting the above range is beneficial for the structural design and production process of the optical lens.

[0077] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -4.5 < f1 / f < -3.0. Meeting the above range can make the first lens have an appropriate negative optical power, which is beneficial to reducing the inclination angle of the incident light rays, facilitating the collection of edge field light rays into the rear optical lenses as much as possible, and achieving large-angle light collection.

[0078] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -4.5 < f2 / f < -2.5. Meeting the above range can make the second lens have an appropriate negative optical power, which can share the negative optical power at the front end of the lens, thereby being beneficial to reducing the excessive light deflection caused by the overly concentrated optical power of the first lens and reducing the difficulty of chromatic aberration correction of the optical lens.

[0079] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -68.0 < f3 / f < -3.0. Meeting the above range can endow the third lens with an appropriate negative optical power, which is beneficial to reducing the light deflection angle, enabling the light to transition smoothly, and improving the imaging quality of the optical lens.

[0080] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.5 < f4 / f < 3.5. Meeting the above range can endow the fourth lens with an appropriate positive optical power, which is beneficial to enhancing the light converging ability of the optical lens. It helps to balance various aberrations generated by the optical lens and improve 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: -5.5 < f5 / f < -3.5. Meeting the above range can endow the fifth lens with an appropriate negative optical power, which is beneficial to increasing the imaging area of the optical lens, optimizing the chromatic aberration of the optical lens, and improving 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: 1.5 < f6 / f < 2.6. Meeting the above range can endow the sixth lens with an appropriate positive optical power, which is beneficial to enhancing the light converging ability of the optical lens, helping to balance various aberrations generated by the optical lens, and improving the imaging quality of the optical lens.

[0083] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 3.0 < f7 / f < 7.0. Meeting the above range can endow the seventh lens with 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.

[0084] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle satisfy: 3.0 < TTL / IH < 4.0. Meeting the above range can effectively balance the requirements of the image height and miniaturization of the optical lens.

[0085] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD satisfy: 5.0 < IH / EPD < 7.5. Meeting the above range can increase the width of the light beam entering the optical lens, improving the brightness at the image plane of the optical lens and avoiding vignetting.

[0086] In some embodiments, the back focal length (BFL) of the optical lens and the effective focal length (f) satisfy: 0.6 < BFL / f < 2.2. Meeting the above range is conducive to achieving a balance between obtaining good imaging quality and an easily assembled back focal length, ensuring the imaging quality of the optical lens while avoiding interference between the lens and other components, and reducing the assembly process difficulty of the camera module.

[0087] In some embodiments, the fifth lens and the sixth lens can be glued together 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 processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0088] In some embodiments, the seventh lens can adopt the aspherical lens surface type to improve the resolution quality.

[0089] To enable the system to have better optical performance, aspherical lenses are used in the lens, and the shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0090]

[0091] Where, z is the distance between the surface and the vertex of the surface in the optical axis direction, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the conic coefficient, and A, B, C, D, E, F are the surface coefficients of the second order, fourth order, sixth order, eighth order, tenth order, and twelfth order respectively.

[0092] The present invention will be further described in multiple embodiments below. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are partially different. For specific differences, please refer to the parameter tables of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any other changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0093] Embodiment 1

[0094] Please refer to Figure 1 , which shows the structural schematic diagram of the optical lens provided in Embodiment 1 of the present invention. The optical lens sequentially 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, a filter G1, and a protective glass G2.

[0095] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0096] The second lens L2 has negative refractive power, and its object-side surface S3 and image-side surface S4 are both concave;

[0097] The third lens L3 has negative refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave;

[0098] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex;

[0099] Aperture ST;

[0100] The fifth lens L5 has negative refractive power, its object-side surface S9 is convex, and its image-side surface S10 is concave;

[0101] The sixth lens L6 has positive refractive power, its object-side surface S10 is convex, and its image-side surface S11 is concave;

[0102] The fifth lens L5 and the sixth lens L6 form a cemented lens group. That is, the cemented surface between the image-side surface of the fifth lens L5 and the object-side surface of the sixth lens L6 is S10.

[0103] The seventh lens L7 has positive refractive power, and its object-side surface S12 and image-side surface S13 are both convex;

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

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

[0106] The imaging surface S18 is a plane.

[0107] The relevant parameters of each lens in the optical lens in Example 1 are shown in Table 1-1.

[0108] Table 1-1

[0109]

[0110] The surface parameters of the aspheric lens of the optical lens in Example 1 are shown in Table 1-2.

[0111] Table 1-2

[0112]

[0113]

[0114] In this embodiment, the field curvature curve, F-Theta distortion curve, relative illumination curve, MTF curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown as follows: Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 shown.

[0115] Figure 2 The field curvature curves for Example 1 are shown, representing 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 a range of -0.06mm to 0.09mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0116] Figure 3 The F-Theta distortion curve for Example 1 is shown, representing the F-Theta distortion of light of different wavelengths at different image heights on the imaging surface. The horizontal axis represents F-Theta distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within a range of -10% to 0, and the image compression at the edge angle area is relatively smooth, effectively improving the clarity of the expanded image.

[0117] Figure 4 The relative illumination curve of Example 1 is shown, which represents the relative illumination values ​​at different field angles on the imaging plane. The horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 40% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0118] Figure 5 The MTF (Modulation Transfer Function) curve for Example 1 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.3 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.

[0119] 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 a range of -20μm to 15μm, indicating that the optical lens can effectively correct axial aberration.

[0120] Figure 7The 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 ±3 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.

[0121] Example 2

[0122] See also Figure 8 , shown is a schematic structural diagram of the optical lens provided in Example 2 of the present invention. Compared with Example 1, this embodiment is different mainly in optical parameters such as the curvature radius of each lens surface and the lens thickness.

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

[0124] Table 2-1

[0125]

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

[0127] Table 2-2

[0128] Face number K A B C D E F S12 -2.00E+02 0.00E+00 -1.18E-03 -9.12E-04 6.32E-05 -5.92E-06 -3.96E-07 S13 4.73E-02 0.00E+00 -1.63E-03 -3.57E-04 3.98E-05 -3.49E-06 1.25E-07

[0129] In this embodiment, the field curvature curve, F-Theta distortion curve, relative illumination curve, MTF curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown as follows: Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 、 Figure 14 shown.

[0130] Figure 9 The field curvature curves for Example 2 are shown, 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 figure, the field curvature of the meridional and sagittal image planes is controlled within -0.03mm to 0.06mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0131] Figure 10The F-Theta distortion curve for Example 2 is shown. It represents the F-Theta distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents F-Theta distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within a range of -8% to 0%, and the image compression at the edge angles is relatively smooth, effectively improving the clarity of the expanded image.

[0132] Figure 11 The relative illumination curve of Example 2 is shown, which represents the relative illumination values ​​at different field angles on the imaging plane. The horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 50% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0133] Figure 12 The MTF (Modulation Transfer Function) curve for Example 2 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.4 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.

[0134] 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 a range of -9 μm to 6 μm, indicating that the optical lens can effectively correct axial aberration.

[0135] Figure 14 The vertical chromatic aberration curve for Example 2 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 a range of -2 μm to 3 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.

[0136] Example 3

[0137] 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, a filter G1, and a protective glass G2.

[0138] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0139] The second lens L2 has negative refractive power, and its object-side surface S3 and image-side surface S4 are both concave;

[0140] The third lens L3 has negative refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave;

[0141] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex;

[0142] Aperture ST;

[0143] The fifth lens L5 has negative refractive power, its object-side surface S9 is convex, and its image-side surface S10 is concave;

[0144] The sixth lens L6 has positive refractive power, its object-side surface S10 is convex, and its image-side surface S11 is concave;

[0145] The fifth lens L5 and the sixth lens L6 form a cemented lens group. That is, the cemented surface between the image-side surface of the fifth lens L5 and the object-side surface of the sixth lens L6 is S10.

[0146] The seventh lens L7 has positive refractive power, its object-side surface S12 is concave, and its image-side surface S13 is convex;

[0147] The object-side surface S14 and the image-side surface S15 of the filter G1 are both flat surfaces;

[0148] The object side surface S16 and the image side surface S17 of the protective glass G2 are both flat surfaces;

[0149] The imaging surface S18 is a plane.

[0150] The relevant parameters of each lens in the optical lens in Example 3 are shown in Table 3-1.

[0151] Table 3-1

[0152]

[0153]

[0154] The surface parameters of the aspheric lens of the optical lens in Example 3 are shown in Table 3-2.

[0155] Table 3-2

[0156] Face number K A B C D E F S12 1.98E+02 0.00E+00 -8.02E-03 5.55E-04 -7.11E-04 1.67E-04 -2.08E-05 S13 5.52E-01 0.00E+00 -6.35E-04 -1.21E-04 -1.78E-05 4.48E-06 -4.68E-07

[0157] In this embodiment, the field curvature curve, F-Theta distortion curve, relative illumination curve, MTF curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown as follows: Figure 16 、 Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 、 Figure 21 shown.

[0158] Figure 16 The field curvature curves for Example 3 are shown, 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 figure, the field curvature of the meridional and sagittal image planes is controlled within a range of -0.09mm to 0.06mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0159] Figure 17 The F-Theta distortion curve for Example 3 is shown. It represents the F-Theta distortion of light of different wavelengths at different image heights on the imaging surface. The horizontal axis represents F-Theta distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within a range of -9% to 0%, and the image compression at the edge angles is relatively smooth, effectively improving the clarity of the expanded image.

[0160] Figure 18 The relative illumination curve of Example 3 is shown, which represents the relative illumination values ​​at different field angles on the imaging plane. The horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 40% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0161] Figure 19 The MTF (Modulation Transfer Function) curve for 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 (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 0.3 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.

[0162] Figure 20The 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 a range of -15μm to 30μm, indicating that the optical lens can effectively correct axial aberration.

[0163] 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 a range of -1 μm to 3 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.

[0164] Example 4

[0165] 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, a filter G1, and a protective glass G2.

[0166] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0167] The second lens L2 has negative refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave;

[0168] The third lens L3 has negative refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave;

[0169] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex;

[0170] Aperture ST;

[0171] The fifth lens L5 has negative refractive power, its object-side surface S9 is convex, and its image-side surface S10 is concave;

[0172] The sixth lens L6 has positive refractive power, and its object-side surface S10 and image-side surface S11 are both convex;

[0173] The fifth lens L5 and the sixth lens L6 form a cemented lens group. That is, the cemented surface between the image-side surface of the fifth lens L5 and the object-side surface of the sixth lens L6 is S10.

[0174] The seventh lens L7 has positive refractive power, its object-side surface S12 is convex, and its image-side surface S13 is concave;

[0175] The object-side surface S14 and the image-side surface S15 of the filter G1 are both flat surfaces;

[0176] The object side surface S16 and the image side surface S17 of the protective glass G2 are both flat surfaces;

[0177] The imaging surface S18 is a plane.

[0178] The relevant parameters of each lens in the optical lens in Example 4 are shown in Table 4-1.

[0179] Table 4-1

[0180]

[0181]

[0182] The surface parameters of the aspheric lens of the optical lens in Example 4 are shown in Table 4-2.

[0183] Table 4-2

[0184] Face number K A B C D E F S12 -1.21E+01 0.00E+00 4.91E-03 -6.61E-04 2.91E-05 -4.24E-07 -7.90E-08 S13 -3.04E+00 0.00E+00 1.36E-03 -2.22E-04 -4.27E-06 1.82E-08 8.02E-09

[0185] In this embodiment, the field curvature curve, F-Theta distortion curve, relative illumination curve, MTF curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown as follows: Figure 23 、 Figure 24 、 Figure 25 、 Figure 26 、 Figure 27 、 Figure 28 shown.

[0186] Figure 23 The field curvature curves for Example 4 are shown, 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 figure, the field curvature of the meridional and sagittal image planes is controlled within a range of -0.08mm to 0.04mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0187] Figure 24 The F-Theta distortion curve for Example 4 is shown. It represents the F-Theta distortion of light of different wavelengths at different image heights on the imaging surface. The horizontal axis represents F-Theta distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within a range of -9% to 0%, and the image compression at the edge angles is relatively smooth, effectively improving the clarity of the expanded image.

[0188] Figure 25 The relative illumination curve of Example 4 is shown, which represents the relative illumination values ​​at different field angles on the imaging surface. The horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, 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 good relative illumination.

[0189] Figure 26 The MTF (Modulation Transfer Function) curve for 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 example is consistently above 0.3 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.

[0190] 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 a range of -10μm to 15μm, indicating that the optical lens can effectively correct axial aberration.

[0191] 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 -5 μm to 6 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.

[0192] Please refer to Table 5, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture value FNO, true image height IH and maximum field of view FOV of the optical lens, as well as the numerical values ​​corresponding to each conditional expression in each embodiment.

[0193] Table 5

[0194]

[0195]

[0196] In summary of the above embodiments, the optical lens provided by the present invention improves the field curvature of the optical lens, reduces aberrations, and improves the imaging quality of the optical lens through the reasonable configuration of the surface shapes of each lens and the reasonable matching of the optical power.

[0197] 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.

[0198] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An optical lens, comprising seven lenses, characterized in that: Along the optical axis from the object side to the imaging surface, it includes: a first lens having negative optical power, wherein the object-side surface is convex and the image-side surface is concave; a second lens element having negative optical power and a concave image-side surface; The third lens has a negative optical power, with a convex object-side surface and a concave image-side surface; 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 convex and whose image-side surface is concave; a sixth lens element having positive optical power and a convex object-side surface; a seventh lens having positive optical power; The effective focal length f of the optical lens and the center thickness CT3 of the third lens along the optical axis satisfy: 2.5 <CT3 / f<4.5。 2. The optical lens according to claim 1, wherein: The total optical length TTL and effective focal length f of the optical lens satisfy: 11.0 <TTL / f<13.5。 3. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens, the arc θ of the maximum half field angle, and the real image height IH corresponding to the maximum field angle satisfy the following: 0.9<(IH / 2) / (f×θ)<1.

0.

4. The optical lens according to claim 1, wherein: The maximum field of view FOV and aperture value FNO of the optical lens meet the following requirements: 100° <FOV / FNO<140°。 5. The optical lens according to claim 1, wherein: The object-side curvature radius R5 of the third lens and the image-side curvature radius R6 of the third lens satisfy the following relationship: 0.1<(R5-R6) / (R5+R6)<0.

8.

6. 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 seventh lenses along the optical axis respectively satisfy the following: 0.5<ΣCT / TTL<0.

7.

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: -4.5 <f1 / f<-3.0。 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: -4.5 <f2 / f<-2.5。 9. 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: -68.0 <f3 / f<-3.0。 10. 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: 1.5 <f4 / f<3.5。

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