Optical lens

Abstract

An optical lens, comprising seven lenses which sequentially include, from an object side to an imaging surface along an optical axis: a first lens (L1) having negative focal power, both the object side surface (S1) and the image side surface (S2) thereof being concave surfaces; a second lens (L2) having positive focal power, the image side surface (S4) thereof being a convex surface; a third lens (L3) having positive focal power, the object side surface (S5) thereof being a concave surface, and the image side surface (S6) thereof being a convex surface; a fourth lens (L4) having positive focal power, both the object side surface (S7) and the image side surface (S8) thereof being convex surfaces; a fifth lens (L5) having positive focal power, both the object side surface (S9) and the image side surface (S10) thereof being convex surfaces; a sixth lens (L6) having negative focal power, both the object side surface (S10) and the image side surface (S11) thereof being concave surfaces; and a seventh lens (L7) having positive focal power, the object side surface (S12) thereof being a convex surface. According to the optical lens, by means of rational configuration of surface profiles of the lenses and rational combination of focal power, the imaging quality of the optical lens is enhanced, and the aberration is reduced, improving the imaging quality of the optical lens.

Description

Optical lens

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese application No. 2023115891031, filed on November 27, 2023, which is incorporated herein by reference in its entirety for all purposes. Technical Field

[0003] The present application relates to the technical field of imaging lenses, and in particular to an optical lens. Background Art

[0004] 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.

[0005] Advanced Driver Assistance Systems (ADAS) play a crucial role in intelligent driving. They use various lenses and sensors to collect environmental information to ensure driver safety. Existing ADAS systems require not only a thin, compact form factor with high pixel count and resolution, but also the ability to produce clear images in low-light conditions. Therefore, developing an optical lens with excellent imaging performance is crucial.

[0006] Application Contents

[0007] In view of the above problems, the purpose of this application is to provide an optical lens with the advantage of excellent imaging quality.

[0008] The present application provides an optical lens having a total of seven lenses, which include the following lenses in order from the object side to the imaging surface along the optical axis:

[0009] a first lens having negative optical power, wherein both the object-side surface and the image-side surface are concave;

[0010] a second lens having positive refractive power and a convex image-side surface;

[0011] The third lens has positive optical power, its object-side surface is concave and its image-side surface is convex;

[0012] The fourth lens element has positive refractive power, and both the object-side surface and the image-side surface are convex;

[0013] The fifth lens has positive refractive power, and both the object-side surface and the image-side surface are convex;

[0014] a sixth lens element having negative optical power, wherein both the object-side surface and the image-side surface are concave;

[0015] a seventh lens element having positive optical power and a convex object-side surface;

[0016] The object-side curvature radius R1 of the first lens and the image-side curvature radius R2 of the first lens satisfy: |(R1-R2) / (R1+R2)|>1.2.

[0017] Further preferably, a curvature radius R7 of the object side surface of the fourth lens and a curvature radius R8 of the image side surface of the fourth lens satisfy: -15.0<(R7-R8) / (R7+R8)<-6.0.

[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: (R5+R6) / (R5-R6)<-25.0.

[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: 0.6<ΣCT / TTL<0.7.

[0020] Further preferably, the semi-aperture d1 of the object side of the first lens, the real image height ih corresponding to the maximum half field angle of the optical lens, and the maximum field angle FOV meet the following conditions: 0.65 <d1 / ih / Tan(FOV / 2)<0.8。

[0021] Further preferably, the effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: -5.5 <f12 / f<-2.5。

[0022] Further preferably, the combined focal length f12 of the first lens and the second lens and the combined focal length f37 of the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -4.0 <f12 / f37<-2.0。

[0023] Further preferably, the maximum field of view FOV and aperture value FNO of the optical lens meet the following requirements: 60° <FOV / FNO<70°。

[0024] Further preferably, the effective focal length f of the optical lens, the real image height ih corresponding to the maximum half field angle of the optical lens, and the maximum field angle FOV satisfy: 0.55 <ih / (f×Tan(FOV / 2))<0.7。

[0025] Further preferably, the effective focal length f of the optical lens, the maximum field of view FOV of the optical lens, and the real image height IH corresponding to the maximum field of view satisfy: FOV×f / IH>60°.

[0026] The optical lens provided in this application improves the imaging quality 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

[0027] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0028] FIG1 is a schematic structural diagram of the optical lens in Example 1 of the present application.

[0029] FIG2 is a field curvature curve diagram of the optical lens in Example 1 of the present application.

[0030] FIG3 is an F-Tanθ distortion curve of the optical lens in Example 1 of the present application.

[0031] FIG4 is a relative illumination curve diagram of the optical lens in Example 1 of the present application.

[0032] FIG5 is an MTF curve diagram of the optical lens in Example 1 of the present application.

[0033] FIG6 is a graph showing an axial aberration curve of the optical lens in Example 1 of the present application.

[0034] FIG7 is a vertical axis chromatic aberration curve diagram of the optical lens in Example 1 of the present application.

[0035] FIG8 is a schematic structural diagram of the optical lens in Example 2 of the present application.

[0036] FIG9 is a field curvature curve diagram of the optical lens in Example 2 of the present application.

[0037] FIG10 is an F-Tanθ distortion curve of the optical lens in Example 2 of the present application.

[0038] FIG11 is a relative illumination curve diagram of the optical lens in Example 2 of the present application.

[0039] FIG12 is an MTF curve diagram of the optical lens in Example 2 of the present application.

[0040] FIG13 is a graph showing an axial aberration curve of the optical lens in Example 2 of the present application.

[0041] FIG14 is a vertical axis chromatic aberration curve diagram of the optical lens in Example 2 of the present application.

[0042] Figure 15 is a schematic structural diagram of the optical lens in Example 3 of the present application.

[0043] FIG16 is a graph showing the field curvature of the optical lens in Example 3 of the present application.

[0044] FIG17 is an F-Tanθ distortion curve of the optical lens in Example 3 of the present application.

[0045] FIG18 is a relative illumination curve diagram of the optical lens in Example 3 of the present application.

[0046] FIG19 is an MTF curve diagram of the optical lens in Example 3 of the present application.

[0047] FIG20 is a graph showing the axial aberration of the optical lens in Example 3 of the present application.

[0048] FIG21 is a vertical axis chromatic aberration curve diagram of the optical lens in Example 3 of the present application.

[0049] Figure 22 is a schematic diagram of the structure of the optical lens in Example 4 of the present application.

[0050] Figure 23 is a field curvature curve diagram of the optical lens in Example 4 of the present application.

[0051] Figure 24 is the F-Tanθ distortion curve of the optical lens in Example 4 of the present application.

[0052] Figure 25 is a relative illumination curve of the optical lens in Example 4 of the present application.

[0053] Figure 26 is an MTF curve diagram of the optical lens in Example 4 of the present application.

[0054] Figure 27 is an axial aberration curve diagram of the optical lens in Example 4 of the present application.

[0055] FIG28 is a vertical axis chromatic aberration curve diagram of the optical lens in Example 4 of the present application.

[0056] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0057] 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.

[0058] 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 this application.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] The optical lens of the embodiment of the present application includes, in order from the object side to the imaging surface along the optical axis: a first lens, a second lens, an aperture, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a filter and a protective glass.

[0065] In some embodiments, the first lens may have a negative optical power, and both its object side and image side are concave. The second lens may have a positive optical power, and its image side is convex. The third lens may have a positive optical power, its object side is concave, and its image side is convex. The fourth lens may have a positive optical power, and both its object side and image side are convex. The fifth lens may have a positive optical power, and both its object side and image side are convex. The sixth lens may have a negative optical power, and both its object side and image side are concave. The seventh lens may have a positive optical power, and its object side is convex.

[0066] In some embodiments, the radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side of the first lens satisfy: |(R1 - R2) / (R1 + R2)| > 1.2. Meeting the above range can avoid the first lens from being too convex in shape and provide a large viewing angle and sufficient light input, improving the imaging quality of the optical lens.

[0067] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f satisfy: 4.5 < TTL / f < 5.2. Meeting the above range enables the overall length to be controlled within a reasonable range.

[0068] In some embodiments, the maximum field of view FOV of the optical lens and the f-number FNO satisfy: 60° < FOV / FNO < 70°. Meeting the above range can achieve a balance between a large field of view and a large aperture.

[0069] In some embodiments, the effective focal length f of the optical lens, the true image height ih corresponding to the maximum semi-field angle of the optical lens, and the maximum field of view FOV satisfy: 0.55 < ih / (f × Tan(FOV / 2)) < 0.7. Meeting the above range controls the distortion within a reasonable range.

[0070] In some embodiments, the true image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD satisfy: 2.2 < IH / EPD < 3.0. Meeting the above range ensures high color reproducibility even with a relatively large entrance pupil diameter, and the optical lens can still have good imaging performance even in low-light environments.

[0071] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL satisfy: BFL / f > 0.8. Meeting the above range and maintaining a relatively long back focal length is beneficial for adjusting the distribution of the optical power of each lens, providing more optimization space for various aberrations of the optical lens.

[0072] In some embodiments, the effective focal length f of the optical lens, the maximum field of view FOV of the optical lens, and the true image height IH corresponding to the maximum field of view satisfy: FOV × f / IH > 60°. Meeting the design requirements for a long focal length and a large field of view.

[0073] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.7 < f1 / f < -1.0. Meeting the above range can endow the first lens with an appropriate negative optical power, which is beneficial to increasing the incident angle of light and the turning of the optical path, and improving the imaging quality of the optical imaging lens.

[0074] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 2.5 < f2 / f < 3.5. Meeting the above range can endow the second lens with an appropriate positive optical power, which is beneficial to improving the light converging ability of the optical lens, and at the same time can balance various aberrations generated by the optical lens, thus improving the imaging quality of the optical lens.

[0075] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 8.0 < f3 / f < 11.0. Meeting the above range can endow the third lens with an appropriate positive optical power, which can converge light while reducing the light deflection angle, making the light trend transition smoothly, and at the same time can balance various aberrations generated by the optical lens, thus improving the imaging quality of the optical lens.

[0076] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.0 < f4 / f < 2.7. Meeting the above range can endow the fourth lens with an appropriate positive optical power, which can converge light while reducing the light deflection angle, making the light trend transition smoothly, and at the same time can balance various aberrations generated by the optical lens, thus improving the imaging quality of the optical lens.

[0077] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.5 < f5 / f < 2.0. Meeting the above range can endow the fifth lens with an appropriate positive optical power, which can converge light while reducing the light deflection angle, making the light trend transition smoothly, and improving the imaging quality of the optical lens.

[0078] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.3 < f6 / f < -0.8. Meeting the above range can endow the sixth lens with an appropriate negative optical power, which is beneficial to balancing the coma generated by the fifth lens and the astigmatism of the lens.

[0079] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 2.5 < f7 / f < 3.5. 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 at the same time can balance the aberrations of the optical lens, thus improving the imaging quality of the optical lens.

[0080] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: -15.0 < (R7 - R8) / (R7 + R8) < -6.0. By satisfying the above range and controlling the absolute values of the radii of curvature of the object side surface and the image side surface of the fourth lens to be close to each other, the axial aberration can be effectively corrected, and the imaging quality of the optical lens can be improved.

[0081] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: (R5 + R6) / (R5 - R6) < -25.0. By satisfying the above range and controlling the radii of curvature of the object side surface and the image side surface of the third lens to be close to each other, the degree of deflection of light passing through the lens can be alleviated, and the aberration can be effectively reduced.

[0082] 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: 0.6 < ∑CT / TTL < 0.7. By satisfying the above range, it is beneficial to the structural design and production process of the optical lens.

[0083] In some embodiments, the clear aperture radius d1 of the object side surface of the first lens, the true image height ih corresponding to the maximum half field angle of the optical lens, and the maximum field angle FOV satisfy: 0.65 < d1 / ih / Tan(FOV / 2) < 0.8. By satisfying the above range, the relationship between the front port diameter, the field angle, and the image plane size of the optical lens can be balanced, which is beneficial to miniaturization.

[0084] In some embodiments, the effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: -5.5 < f12 / f < -2.5. By satisfying the above range, the front lens group of the optical lens adopts a negative lens group, which can effectively increase the field angle and at the same time offset the astigmatism caused by light concentration, so that the light can be evenly distributed, and the overall relative illumination of the imaging plane can be improved.

[0085] In some embodiments, the combined focal length f12 of the first lens and the second lens and the combined focal length f37 of the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: -4.0 < f12 / f37 < -2.0. By satisfying the above range, the optical lens has a strong optical power at the rear end, which is beneficial to the correction of various aberrations, especially to improve the imaging quality of the edge field of view.

[0086] 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 eccentricity sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0087] In order to make the system have better optical performance, multiple aspheric lenses are used in the lens. The shape of each aspheric surface of the optical lens satisfies the following equation:

[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 application is further described below with reference to a number of 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 application, but the embodiments of the present application are not limited solely to the following embodiments. Any other changes, substitutions, combinations, or simplifications that do not deviate from the innovative aspects of the present application shall be deemed equivalent replacements and are included within the scope of protection of the present application.

[0090] Example 1

[0091] Please refer to Figure 1, which is a schematic diagram of the structure of the optical lens provided in Example 1 of the present application. The optical lens includes, along the optical axis from the object side to the imaging surface, the following: a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1 and a protective glass G2.

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

[0093] The second lens L2 has positive refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0094] Aperture ST;

[0095] The third lens L3 has positive refractive power, its object-side surface S5 is concave, and its image-side surface S6 is 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 positive refractive power, and its object-side surface S9 and image-side surface S10 are both convex;

[0098] The sixth lens L6 has negative refractive power, and its object-side surface S10 and image-side surface S11 are both concave;

[0099] 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.

[0100] The seventh lens L7 has positive refractive power, and its object-side surface S12 and image-side surface S13 are both convex;

[0101] The object-side surface S14 and the image-side surface S15 of the filter G1 are both flat surfaces;

[0102] The object side surface S16 and the image side surface S17 of the protective glass G2 are both flat surfaces;

[0103] The imaging surface S18 is a plane.

[0104] The relevant parameters of each lens in the optical lens in Example 1 are shown in Table 1-1.

[0105] Table 1-1

[0106] The surface parameters of the aspheric lens of the optical lens in Example 1 are shown in Table 1-2.

[0107] Table 1-2

[0108] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown in Figures 2, 3, 4, 5, 6, and 7, respectively.

[0109] Figure 2 shows the field curvature curves of Example 1, 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 ±0.04mm, indicating that the optical lens is capable of effectively correcting field curvature.

[0110] Figure 3 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 the F-Tanθ distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within a range of -8% to 0%, and the image compression in the edge angle area is relatively smooth, effectively improving the clarity of the expanded image.

[0111] Figure 4 shows the relative illumination curve of Example 1, 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 70% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0112] Figure 5 shows the MTF (Modulation Transfer Function) curve of Example 1, which represents 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 values ​​of this embodiment are 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.

[0113] Figure 6 shows a graph of the axial aberration of Example 1, which shows 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 figure, the offset of the axial aberration is controlled within a range of -6μm to 30μm, indicating that the optical lens is able to correct axial aberration well.

[0114] Figure 7 shows a graph of vertical chromatic aberration for Example 1, showing 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 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.

[0115] Example 2

[0116] Please refer to Figure 8, which is a schematic diagram of the structure of the optical lens provided in Example 2 of the present application. Compared with Example 1, this embodiment is different mainly in optical parameters such as the curvature radius of each lens surface, lens thickness, aspheric surface parameters, etc.

[0117] The relevant parameters of each lens in the optical lens in Example 2 are shown in Table 2-1.

[0118] Table 2-1

[0119] The surface parameters of the aspheric lens of the optical lens in Example 2 are shown in Table 2-2.

[0120] Table 2-2

[0121] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown in Figures 9, 10, 11, 12, 13, and 14, respectively.

[0122] Figure 9 shows the field curvature curves for Example 2, 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 ±0.04mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0123] Figure 10 shows the F-Tanθ distortion curve for Example 2, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within a range of -8% to 0%, and the image compression in the edge angle area is relatively smooth, effectively improving the clarity of the expanded image.

[0124] Figure 11 shows the relative illumination curve of Example 2, 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 70% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0125] Figure 12 shows the MTF (Modulation Transfer Function) curve of Example 2, which represents 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 figure, the MTF value of this embodiment is 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.

[0126] Figure 13 shows a graph of the axial aberration of Example 2, which shows 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 -6μm to 30μm, indicating that the optical lens is able to effectively correct axial aberration.

[0127] Figure 14 shows a graph of vertical chromatic aberration for Example 2, plotting 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 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 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.

[0128] Example 3

[0129] Please refer to Figure 15, which is a schematic diagram of the structure of the optical lens provided in Example 3 of the present application. Compared with Example 1, this embodiment differs in that the object-side surface S3 of the second lens L2 is convex, and the optical parameters such as the curvature radius, lens thickness, and aspheric surface parameters of each lens surface are different.

[0130] The relevant parameters of each lens in the optical lens in Example 3 are shown in Table 3-1.

[0131] Table 3-1

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

[0133] Table 3-2

[0134] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown in Figures 16, 17, 18, 19, 20, and 21, respectively.

[0135] Figure 16 shows the field curvature curves for Example 3, 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 ±0.06mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0136] Figure 17 shows the F-Tanθ distortion curve for Example 3, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within a range of -8% to 0%, and the image compression in the edge angle region is relatively smooth, effectively improving the clarity of the expanded image.

[0137] Figure 18 shows the relative illumination curve of Example 3, 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 70% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0138] Figure 19 shows the MTF (Modulation Transfer Function) curve of Example 3, which represents 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 figure, the MTF value of this embodiment is 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.

[0139] Figure 20 shows a graph of the axial aberration of Example 3, which shows 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 figure, the offset of the axial aberration is controlled within a range of -18μm to 30μm, indicating that the optical lens is able to correct axial aberration well.

[0140] Figure 21 shows a graph of vertical chromatic aberration for Example 3, plotting 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 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 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.

[0141] Example 4

[0142] Please refer to FIG. 22 , which is a schematic diagram of the structure of the optical lens provided in Example 4 of the present application. This embodiment differs from Example 1 in that the image-side surface S13 of the seventh lens element L7 is concave, and the optical parameters such as the curvature radius, lens thickness, and aspheric surface parameters of each lens surface are different.

[0143] The relevant parameters of each lens in the optical lens in Example 4 are shown in Table 4-1.

[0144] Table 4-1

[0145] The surface parameters of the aspheric lens of the optical lens in Example 4 are shown in Table 4-2.

[0146] Table 4-2

[0147] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown in Figures 23, 24, 25, 26, 27, and 28, respectively.

[0148] Figure 23 shows the field curvature curves for Example 4, 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 -0.08mm to 0.04mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0149] Figure 24 shows the F-Tanθ distortion curve for Example 4, which shows the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging surface. The horizontal axis represents the F-Tanθ distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within a range of -10% to 0%, and the image compression in the edge angle region is relatively smooth, effectively improving the clarity of the expanded image.

[0150] Figure 25 shows the relative illumination curve of Example 4, 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 70% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0151] Figure 26 shows the MTF (Modulation Transfer Function) curve of Example 4, which represents 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 figure, the MTF value of this embodiment is 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.

[0152] Figure 27 shows a graph of the axial aberration of Example 4, which shows 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 figure, the offset of the axial aberration is controlled within ±18 μm, indicating that the optical lens is able to correct axial aberration well.

[0153] Figure 28 shows a graph of vertical chromatic aberration for Example 4, plotting 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 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.

[0154] 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, real image height IH corresponding to the maximum field of view angle, chief ray incidence angle CRA, and maximum field of view angle FOV of the optical lens, as well as the numerical values ​​corresponding to each conditional expression in each embodiment.

[0155] Table 5

[0156] In summary of the above embodiments, the optical lens provided in the present application improves the imaging quality 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.

[0157] 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 application. 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.

[0158] The above-described embodiments merely represent several implementation methods of the present application. While the 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 of ordinary skill in the art may make various modifications 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: The first lens has negative optical power, and both the object side surface and the image side surface are concave; A second lens having positive refractive power and a convex image-side surface; The third lens has positive power, its object side surface is concave and its image side surface is convex; The fourth lens has positive refractive power, and both the object side surface and the image side surface are convex; A fifth lens having positive refractive power, whose object-side surface and image-side surface are both convex; The sixth lens has negative optical power, and both the object side surface and the image side surface are concave; a seventh lens element having positive refractive power and having a convex object side surface; The object-side curvature radius R1 of the first lens and the image-side curvature radius R2 of the first lens satisfy: |(R1-R2) / (R1+R2)|>1.

2.

2. The optical lens according to claim 1, characterized in that: The object-side curvature radius R7 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy: -15.0<(R7-R8) / (R7+R8)<-6.

0.

3. The optical lens according to claim 1, characterized in that: The object side curvature radius R5 of the third lens and the image side curvature radius R6 of the third lens satisfy: (R5+R6) / (R5-R6)<-25.

0.

4. The optical lens according to claim 1, characterized in that: 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: 0.6<ΣCT / TTL<0.

7.

5. The optical lens according to claim 1, characterized in that: The semi-aperture d1 of the object side of the first lens, the real image height ih corresponding to the maximum half-angle of view of the optical lens, and the maximum angle of view FOV satisfy: 0.65 <d1 / ih / Tan(FOV / 2)<0.8。 6. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: -5.5 <f12 / f<-2.5。 7. The optical lens according to claim 1, characterized in that: The combined focal length f12 of the first lens and the second lens and the combined focal length f37 of the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -4.0 <f12 / f37<-2.0。 8. The optical lens according to claim 1, characterized in that: The maximum field of view FOV and aperture value FNO of the optical lens meet the following requirements: 60° <FOV / FNO<70°。 9. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens, the real image height ih corresponding to the maximum half field of view of the optical lens, and the maximum field of view FOV satisfy the following requirements: 0.55 <ih / (f×Tan(FOV / 2))<0.7。 10. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens, the maximum field of view FOV of the optical lens and the real image height IH corresponding to the maximum field of view satisfy: FOV×f / IH>60°.

Images