Optical lens

Abstract

The application provides an optical lens, which comprises seven lenses in sequence along an optical axis from an object side to an imaging surface, and comprises a first lens with positive refractive power; a second lens with positive refractive power, the object side of which is concave, and the image side of which is convex; a third lens with positive refractive power, the object side and the image side of which are both convex; a fourth lens with positive refractive power, the object side and the image side of which are both convex; a fifth lens with negative refractive power, the object side and the image side of which are both concave; a sixth lens with positive refractive power, the object side of which is convex, and the image side of which is concave; and a seventh lens with positive refractive power, the object side of which is convex, and the image side of which is concave; and the optical total length TTL of the optical lens and the effective focal length f satisfy: TTL / f < 2.5. The optical lens provided by the application improves the imaging quality of the optical lens, reduces aberration, and improves the imaging quality of the optical lens through reasonable configuration of the surface shape of each lens and reasonable matching of the refractive power.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of imaging lenses, in particular to an optical lens. BACKGROUND

[0002] With the continuous improvement of people's requirements for driving experience, vehicle application type optical lenses are used more and more in intelligent driving, and the position of vehicle optical lenses in the automobile industry is continuously improved.

[0003] Advanced Driver Assistance System (ADAS) plays an important role in intelligent driving, which collects environmental information through various lenses combined with sensors to ensure the safety of drivers. The lenses of the existing ADAS system need a longer focal length in long-distance imaging, but a longer focal length will result in a longer total length of the lens, which is not conducive to the miniaturization of the lens. At the same time, such lenses need a larger aperture, so that they also have good imaging quality in the night or in the environment with weak light. Therefore, it is necessary to develop optical lenses with long focal length, small size, low cost, high resolution, and can be used in weak light and harsh environment. SUMMARY

[0004] In view of the above problems, the purpose of the present application is to provide an optical lens with the advantages of long focal length, small size, low cost, high resolution, and can be used in weak light and harsh environment.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is:

[0006] An optical lens, a total of seven lenses, including in order along the optical axis from the object side to the imaging surface:

[0007] A first lens with positive refractive power;

[0008] A second lens with positive refractive power, the object side surface is concave, and the image side surface is convex;

[0009] A third lens with positive refractive power, both the object side surface and the image side surface are convex;

[0010] A fourth lens with positive refractive power, both the object side surface and the image side surface are convex;

[0011] A fifth lens with negative refractive power, both the object side surface and the image side surface are concave;

[0012] A sixth lens with positive refractive power, the object side surface is convex, and the image side surface is concave;

[0013] A seventh lens with positive refractive power, the object side surface is convex, and the image side surface is concave;

[0014] An optical total length TTL of the optical lens and an effective focal length f satisfy: TTL / f<2.5.

[0015] Further preferably, a curvature radius R1 of an object side surface of the first lens and a curvature radius R2 of an image side surface of the first lens satisfy: |(R1+R2) / (R1-R2)|>20.0.

[0016] Further preferably, a curvature radius R3 of an object side surface of the second lens and a curvature radius R4 of an image side surface of the second lens satisfy: (R3+R4) / (R3-R4)>10.0.

[0017] Further preferably, a curvature radius R11 of an object side surface of the sixth lens and a curvature radius R12 of an image side surface of the sixth lens satisfy: |(R11+R12) / (R11-R12)|>10.0.

[0018] Further preferably, a curvature radius R13 of an object side surface of the seventh lens and a curvature radius R14 of an image side surface of the seventh lens satisfy: |(R13+R14) / (R13-R14)|>10.0.

[0019] Further preferably, an optical total length TTL of the optical lens and a sum ∑CT of central thicknesses of the first lens to the seventh lens along the optical axis respectively satisfy: ∑CT / TTL>0.55.

[0020] Further preferably, an effective focal length f of the optical lens and a real image height ih corresponding to a maximum field of view angle FOV and a maximum half field of view angle satisfy: 0.95<ih / (fxtan(FOV / 2))<1.05.

[0021] Further preferably, a maximum field of view angle FOV of the optical lens and an aperture value FNO satisfy: 12.0°<FOV / FNO<25.0°.

[0022] Further preferably, an effective focal length f of the optical lens and an optical back focal length BFL satisfy: BFL / f>0.25.

[0023] Further preferably, an effective focal length f of the optical lens and a focal length f1 of the first lens satisfy: f1 / f>15.0.

[0024] The optical lens provided by the present application improves the imaging quality of the optical lens, reduces aberration, improves the imaging quality of the optical lens, and realizes the effects of long focal length, small size, low cost, high resolution, and use in weak light and harsh environments. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings of which:

[0026] Figure 1 A structure diagram of an optical lens in Embodiment 1 of the present application.

[0027] Figure 2 A field curvature curve of the optical lens in Embodiment 1 of the present application.

[0028] Figure 3 An F-Tanθ distortion curve of the optical lens in Embodiment 1 of the present application.

[0029] Figure 4 A relative luminance curve of the optical lens in Embodiment 1 of the present application.

[0030] Figure 5 An MTF curve of the optical lens in Embodiment 1 of the present application.

[0031] Figure 6 An axial aberration curve of the optical lens in Embodiment 1 of the present application.

[0032] Figure 7 A sagittal color aberration curve of the optical lens in Embodiment 1 of the present application.

[0033] Figure 8 A structure diagram of an optical lens in Embodiment 2 of the present application.

[0034] Figure 9 A field curvature curve of the optical lens in Embodiment 2 of the present application.

[0035] Figure 10 An F-Tanθ distortion curve of the optical lens in Embodiment 2 of the present application.

[0036] Figure 11 A relative luminance curve of the optical lens in Embodiment 2 of the present application.

[0037] Figure 12 An MTF curve of the optical lens in Embodiment 2 of the present application.

[0038] Figure 13 An axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0039] Figure 14 A sagittal color aberration curve of the optical lens in Embodiment 2 of the present application.

[0040] Figure 15 A structure diagram of an optical lens in Embodiment 3 of the present application.

[0041] Figure 16The field curvature curve of the optical lens in Embodiment 3 of the present application.

[0042] Figure 17 The F-Tanθ distortion curve of the optical lens in Embodiment 3 of the present application.

[0043] Figure 18 The relative illumination curve of the optical lens in Embodiment 3 of the present application.

[0044] Figure 19 The MTF curve of the optical lens in Embodiment 3 of the present application.

[0045] Figure 20 The axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0046] Figure 21 The lateral chromatic aberration curve of the optical lens in Embodiment 3 of the present application.

[0047] Figure 22 The structural schematic diagram of the optical lens in Embodiment 4 of the present application.

[0048] Figure 23 The field curvature curve of the optical lens in Embodiment 4 of the present application.

[0049] Figure 24 The F-Tanθ distortion curve of the optical lens in Embodiment 4 of the present application.

[0050] Figure 25 The relative illumination curve of the optical lens in Embodiment 4 of the present application.

[0051] Figure 26 The MTF curve of the optical lens in Embodiment 4 of the present application.

[0052] Figure 27 The axial aberration curve of the optical lens in Embodiment 4 of the present application.

[0053] Figure 28 The lateral chromatic aberration curve of the optical lens in Embodiment 4 of the present application.

[0054] Figure 29 The structural schematic diagram of the optical lens in Embodiment 5 of the present application.

[0055] Figure 30 The field curvature curve of the optical lens in Embodiment 5 of the present application.

[0056] Figure 31 The F-Tanθ distortion curve of the optical lens in Embodiment 5 of the present application.

[0057] Figure 32 The relative illumination curve of the optical lens in Embodiment 5 of the present application.

[0058] Figure 33 MTF curve graph of the optical lens in Embodiment 5 of the present application.

[0059] Figure 34 Axial aberration curve graph of the optical lens in Embodiment 5 of the present application.

[0060] Figure 35 Vignetting curve graph of the optical lens in Embodiment 5 of the present application. The present application will be further described in conjunction with the above-mentioned drawings in the following DETAILED DESCRIPTION. DETAILED DESCRIPTION

[0061] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be noted that these detailed descriptions are only examples of embodiments of the present application and are not intended to limit the scope of the present application in any way. Throughout the specification, like reference numerals refer to like elements. The expression “and / or” includes any and all combinations of one or more of the associated listed items.

[0062] It should be noted that the expressions first, second, third, etc. in the present specification are merely used to distinguish one feature from another feature, and do not represent any limitation on the features. Thus, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0063] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0064] In this context, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.

[0065] It should also be understood that the use of the terms "including", "including having", "having", "containing", and / or "containing having" when used in this specification intends that existence of stated features, elements and / or components but does not exclude the presence or addition of one or more other features, elements, components, and / or groups thereof. In addition, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the term "exemplary" is intended to refer to an example or illustration.

[0066] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that the terms should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0067] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0068] The optical lens of the embodiments of the present application comprises, in order from the object side to the imaging surface along the optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a filter and a protective glass. The diaphragm is arranged between the second lens and the third lens or between the third lens and the fourth lens.

[0069] In some embodiments, the first lens can have positive refractive power. The second lens can have positive refractive power, with the object side surface being concave and the image side surface being convex. The third lens can have positive refractive power, with both the object side surface and the image side surface being convex. The fourth lens can have positive refractive power, with both the object side surface and the image side surface being convex. The fifth lens can have negative refractive power, with both the object side surface and the image side surface being concave. The sixth lens can have positive refractive power, with the object side surface being convex and the image side surface being concave. The seventh lens can have positive refractive power, with the object side surface being convex and the image side surface being concave.

[0070] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f satisfy: TTL / f < 2.5. Satisfying the above range can effectively control the length of the optical lens, which is beneficial to realize the miniaturization of the optical lens.

[0071] In some embodiments, the radius of curvature R1 of the object-side surface of the first lens and the radius of curvature R2 of the image-side surface of the first lens satisfy: |(R1+R2) / (R1-R2)|>20.0. By satisfying the above range, the direction of light rays can be controlled, the depth of field can be increased, spherical aberration can be reduced, coma can be corrected, light utilization can be increased, and stability can be improved by using a meniscus lens.

[0072] In some embodiments, the radius of curvature R3 of the object-side surface of the second lens and the radius of curvature R4 of the image-side surface of the second lens satisfy: (R3+R4) / (R3-R4)>10.0. By satisfying the above range, the direction of light rays can be further controlled, the back focal length can be reduced, the imaging quality can be improved, light utilization can be increased, and the object-side surface and the image-side surface have similar curvatures, which is conducive to smooth transition of light rays and reduces sensitivity.

[0073] In some embodiments, the radius of curvature R11 of the object-side surface of the sixth lens and the radius of curvature R12 of the image-side surface of the sixth lens satisfy: |(R11+R12) / (R11-R12)|>10.0. By satisfying the above range, the direction of light rays can be further controlled, the back focal length can be reduced, the imaging quality can be improved, and light utilization can be increased by using a meniscus lens.

[0074] In some embodiments, the radius of curvature R13 of the object-side surface of the seventh lens and the radius of curvature R14 of the image-side surface of the seventh lens satisfy: |(R13+R14) / (R13-R14)|>10.0. By satisfying the above range, the direction of light rays can be further controlled, the back focal length can be reduced, the imaging quality can be improved, and light utilization can be increased by using a meniscus lens.

[0075] In some embodiments, the total 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: ∑CT / TTL>0.55. By satisfying the above range, the focal length of the optical lens is increased, and a more distant or wider range of scenes can be received.

[0076] In some embodiments, the effective focal length f of the optical lens, the maximum field of view FOV, and the real image height ih corresponding to the maximum half field of view satisfy: 0.95<ih / (fxtan(FOV / 2))<1.05. By satisfying the above range, the distortion of the image edge can be reduced, the overall image quality can be improved, the difficulty of post-image processing can be reduced, the influence of temperature drift can be reduced, and the stability and reliability of the optical lens can be improved.

[0077] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value FNO satisfy: 12.0°<FOV / FNO<25.0°. By satisfying the above range, the amount of light entering the optical lens is increased, the night imaging quality is improved, and noise is reduced; the depth of field is larger, and a distant target can be clearly photographed.

[0078] In some embodiments, the effective focal length f of the optical lens and the optical back focal length BFL satisfy: BFL / f>0.25. Satisfying the above range can reduce the interference of aberrations such as aberrations and coma, and improve the resolution and clarity of imaging; and improve the stability of the optical lens.

[0079] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: f1 / f>15.0. Satisfying the above range enables the first lens to have a larger positive refractive power, ensures that the light rays exiting the first lens can still maintain an upward trend, and under the same field of view angle condition, the light rays exiting the image side of the first lens can make the subsequent optical system have a larger light acceptance surface, which is beneficial to the enlargement of the image surface on the one hand, and can realize a larger physical aperture of the stop and a larger aperture, and can realize a larger light amount and increase the brightness of the imaging surface.

[0080] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 0<f2 / f<10.0. Satisfying the above range enables the second lens to have a proper positive refractive power, which is beneficial to the convergence of light rays while reducing the light deflection angle, smoothly transitions the light rays, and improves the imaging quality of the optical lens.

[0081] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0<f3 / f<2.0. Satisfying the above range enables the third lens to have a proper positive refractive power, which is beneficial to the convergence of light rays while reducing the light deflection angle, smoothly transitions the light rays, and improves the imaging quality of the optical lens.

[0082] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0<f4 / f<1.5. Satisfying the above range enables the fourth lens to have a proper positive refractive power, which is beneficial to the smooth transition of light rays, corrects various aberrations of the optical lens, and improves the imaging quality of the optical lens.

[0083] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.0<f5 / f<0. Satisfying the above range enables the fifth lens to have a proper negative refractive power, which can balance the spherical aberration generated by the front lens of the optical lens, and improve the imaging quality of the optical lens.

[0084] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0<f6 / f<15.0. Satisfying the above range enables the sixth lens to have a proper positive refractive power, which is beneficial to the smooth transition of light rays, corrects various aberrations of the optical lens, improves the imaging quality of the optical lens, and converges light rays to improve the relative luminance.

[0085] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 0 < f7 / f < 4.0. Satisfying the above range makes the seventh lens have proper positive refractive power, is conducive to smooth transition of light rays, corrects various aberrations of the optical lens, and improves the imaging quality of the optical lens; and converging light rays improves relative illumination.

[0086] In some embodiments, the fourth lens and the fifth lens can be bonded to form a bonded lens, which can effectively correct chromatic aberration of the optical lens, reduce eccentricity sensitivity of the optical lens, balance aberration of the optical lens, improve the imaging quality of the optical lens, reduce assembly sensitivity of the optical lens, and further reduce the processing difficulty of the optical lens and improve the assembly yield of the optical lens.

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

[0088]

[0089] Wherein, z is the distance of the curved surface from the vertex of the curved surface in the direction of the optical axis, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the quadratic surface coefficient, 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.

[0090] The application will be further described in the following embodiments. In each embodiment, the thickness, the radius of curvature, and the material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments only, and any changes, substitutions, combinations or simplifications made without departing from the innovative points of the application should be regarded as equivalent replacement modes, and are included in the protection scope of the application.

[0091] Embodiment 1

[0092] Please refer to Figure 1 , which is a structure schematic diagram of an optical lens provided in the embodiment 1 of the application. The optical lens includes, in order from the object side to the imaging surface along the optical axis, a first lens L1, a second lens L2, a diaphragm 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.

[0093] The first lens L1 has positive refractive power, the object side surface S1 thereof is a concave surface, and the image side surface S2 thereof is a convex surface.

[0094] The second lens L2 has positive refractive power, the object side surface S3 thereof is a concave surface, and the image side surface S4 thereof is a convex surface.

[0095] a diaphragm ST;

[0096] The third lens L3 has positive refractive power, and both the object side S5 and the image side S6 are convex surfaces;

[0097] The fourth lens L4 has positive refractive power, and both the object side S7 and the image side S8 are convex surfaces;

[0098] The fifth lens L5 has negative refractive power, and both the object side S8 and the image side S9 are concave surfaces;

[0099] The fourth lens L4 and the fifth lens L5 form a cemented lens group, that is, the cemented surface S8 of the image side of the fourth lens L4 and the object side of the fifth lens L5;

[0100] The sixth lens L6 has positive refractive power, and the object side S10 is a convex surface and the image side S11 is a concave surface;

[0101] The seventh lens L7 has positive refractive power, and the object side S12 is a convex surface and the image side S13 is a concave surface;

[0102] Both the object side S14 and the image side S15 of the filter G1 are flat surfaces;

[0103] Both the object side S16 and the image side S17 of the protective glass G2 are flat surfaces;

[0104] The imaging surface S18 is a flat surface.

[0105] The related parameters of the lenses in the optical lens in Embodiment 1 are shown in Table 1-1.

[0106] Table 1-1

[0107]

[0108] The surface type parameters of the aspherical lenses of the optical lens in Embodiment 1 are shown in Table 1-2.

[0109] Table 1-2

[0110]

[0111]

[0112] In this embodiment, the field curvature curve, the F-Tanθ distortion curve, the relative luminance curve, the MTF curve, the axial aberration curve, and the off-axis chromatic aberration curve of the optical lens are shown in FIGS. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7

[0113] ​Figure 2 The field curvature curve of Example 1 is shown, which represents the curvature of light rays of different wavelengths on the meridional image surface and sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.04mm-0mm, which shows that the optical lens can well correct the field curvature.

[0114] Figure 3 The F-Tanθ distortion curve of Example 1 is shown, which represents the F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging surface, the horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -0.7%-0, the image compression in the edge angle region is relatively flat, and the clarity of the expanded image is effectively improved.

[0115] Figure 4 The relative luminance curve of Example 1 is shown, which represents the relative luminance value of different field angles on the imaging surface, the horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative luminance (unit: %). As can be seen from the figure, the relative luminance value of the optical lens is still greater than 80% at the maximum half field angle, which shows that the optical lens has good relative luminance.

[0116] Figure 5 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies under each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of the present embodiment is above 0.5 within the full field of view, and within the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in low and high frequency conditions.

[0117] Figure 6 The axial aberration curve of Example 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging surface, 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 -10μm-18μm, which shows that the optical lens can well correct the axial aberration.

[0118] Figure 7The vertical axis represents the value of the vertical chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) (unit: μm), and the longitudinal axis represents the normalized field angle. As can be seen from the figure, the vertical chromatic aberration of the longest wavelength and the shortest wavelength is controlled within 0-2 μm, which indicates that the optical lens can very well correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image surface.

[0119] Embodiment 2

[0120] Referring to Figure 8 , a structure schematic diagram of the optical lens provided in Embodiment 2 of the present application is shown, and the optical lens of the present embodiment is substantially the same as that of Embodiment 1, and the main difference is that the object side S1 of the first lens L1 is a convex surface, the image side S2 of the first lens L1 is a concave surface, and the optical parameters such as the curvature radius, aspheric coefficient, thickness, etc. of each lens surface type are different.

[0121] The related parameters of each lens in the optical lens in Embodiment 2 are shown in Table 2-1.

[0122] Table 2-1

[0123]

[0124] The surface type parameters of the aspheric lens of the optical lens in Embodiment 2 are shown in Table 2-2.

[0125] Table 2-2

[0126]

[0127]

[0128] In the present embodiment, the field curvature curve, F-Tanθ distortion curve, relative luminance curve, MTF curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown in Figure 9 , Figure 10 , Figure 11 , Figure 12 , Figure 13 , Figure 14 respectively.

[0129] Figure 9 The field curvature curve of Embodiment 2 is shown, which indicates the bending degree of light rays of different wavelengths on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the longitudinal axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.02 mm-0.06 mm, which indicates that the optical lens can well correct the field curvature.

[0130] Figure 10 F-Tanθ distortion curve of embodiment 2 is shown, which represents F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging plane, the horizontal axis represents F-Tanθ distortion (unit: %), and the vertical axis represents half field angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within 2.5%, and the image compression in the edge angle region is relatively gentle, effectively improving the clarity of the expanded image.

[0131] Figure 11 The relative illumination curve of embodiment 2 is shown, which represents the relative illumination value of different field angles on the imaging plane, the horizontal axis represents half field angle (unit: °), and the vertical axis represents 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.

[0132] Figure 12 The MTF (Modulation Transfer Function) curve of embodiment 2 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies under each field of view, the horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of the embodiment is above 0.5 within the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge field of view, and has good imaging quality and good detail resolution ability in low and high frequency conditions.

[0133] Figure 13 The axial aberration curve of embodiment 2 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane, the horizontal axis represents axial aberration value (unit: μm), and the vertical axis represents normalized pupil radius. As can be seen from the figure, the offset of axial aberration is controlled within -20 μm-10 μm, indicating that the optical lens can better correct axial aberration.

[0134] Figure 14 The axial aberration curve of embodiment 2 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane, the horizontal axis represents axial aberration value (unit: μm), and the vertical axis represents normalized pupil radius. As can be seen from the figure, the offset of axial aberration is controlled within -20 μm-10 μm, indicating that the optical lens can better correct axial aberration.

[0135] Embodiment 3

[0136] Please refer to Figure 15Figure 3 shows a structural schematic diagram of an optical lens provided in Embodiment 3 of the present application. The optical lens of the present embodiment is substantially the same as that of Embodiment 1, except that the object side S1 of the first lens L1 is a convex surface, the image side S2 of the first lens L1 is a concave surface, and the optical parameters such as the curvature radius, asphericity coefficient, and thickness of each lens surface are different.

[0137] The related parameters of each lens in the optical lens of Embodiment 3 are shown in Table 3-1.

[0138] Table 3-1

[0139]

[0140] The surface profile parameters of the aspheric lenses of the optical lens of Embodiment 3 are shown in Table 3-2.

[0141] Table 3-2

[0142] Figure 16 K A B C D E F S1 -1.34E+00 0.00E+00 -5.03E-05 -2.00E-06 -1.41E-08 -3.70E-10 -1.83E-12 S2 4.34E-01 0.00E+00 -2.10E-05 -2.41E-06 6.41E-09 -1.69E-10 -3.75E-11 S5 3.59E+01 0.00E+00 1.92E-06 7.78E-07 -2.17E-08 7.53E-11 9.55E-11 S6 -1.49E+00 0.00E+00 -5.07E-05 -7.07E-07 7.62E-08 -3.89E-10 -4.42E-11 S12 -5.55E-01 0.00E+00 1.55E-04 1.18E-06 2.27E-07 -1.30E-08 2.81E-10 S13 1.26E+00 0.00E+00 1.17E-04 2.93E-05 -1.28E-06 -1.09E-08 2.48E-09

[0143] In the present embodiment, the field curvature curve, F-Tanθ distortion curve, relative luminance curve, MTF curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are shown in Figures 3-1, 3-2, 3-3, 3-4, 3-5, and 3-6, respectively. Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 、 Figure 21 、 Figure 22

[0144] Figure 23 Figure 3-1 shows the field curvature curve of Embodiment 3, which represents the curvature of the meridional image surface and sagittal image surface of light rays of different wavelengths, with the horizontal axis representing the offset (unit: mm) and the vertical axis representing the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and sagittal image surface is controlled within -0.1 mm-0.05 mm, indicating that the optical lens can well correct the field curvature.

[0145] Figure 24 Figure 3-2 shows the F-Tanθ distortion curve of Embodiment 3, which represents the F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging surface, with the horizontal axis representing the F-Tanθ distortion (unit: %) and the vertical axis representing the half field angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -1 %-1 %, and the image compression in the edge angle region is relatively flat, effectively improving the clarity of the expanded image.

[0146] Figure 25 ​The relative illumination curves for Example 3 are shown, representing the relative illumination values ​​at different field-of-view 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.

[0147] Figure 26 The MTF (Modulation Transfer Function) curve of Example 3 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.5 throughout the entire field of view. Within the range of 0–160 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0148] Figure 27 The axial aberration curve of Example 3 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane. 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 axial aberration offset is controlled within -20μm to 10μm, indicating that the optical lens can effectively correct axial aberration.

[0149] Figure 28 The diagram shows the transverse chromatic aberration curves for Example 3, representing the chromatic aberration of each wavelength relative to the center wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1 μm to 2 μm, indicating that the optical lens can effectively correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0150] Example 4

[0151] Please see Figure 23 The figure shows a schematic diagram of the structure of the optical lens provided in Embodiment 4 of the present invention. The optical lens in this embodiment is roughly the same as that in Embodiment 1. The main difference is that the object side S1 of the first lens L1 is a convex surface, the image side S2 of the first lens L1 is a concave surface, and the optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0152] The relevant parameters of each lens in the optical lens of Example 4 are shown in Table 4-1.

[0153] Table 4-1

[0154]

[0155] The surface parameters of the aspherical lens of the optical lens in Example 4 are shown in Table 4-2.

[0156] Table 4-2

[0157] Figure 24 K A B C D E F S1 -1.49E+00 0.00E+00 -5.65E-05 -2.91E-06 -1.80E-08 -1.98E-10 2.24E-12 S2 3.69E-01 0.00E+00 -2.12E-05 -3.38E-06 -2.39E-08 1.04E-10 4.69E-12 S5 4.69E+01 0.00E+00 1.87E-05 2.19E-07 -1.56E-08 9.68E-10 5.21E-11 S6 -1.56E+00 0.00E+00 -4.99E-05 -5.80E-07 5.85E-08 -2.90E-10 1.94E-11 S12 -7.98E-01 0.00E+00 1.05E-04 1.83E-06 1.64E-08 -2.59E-09 9.55E-11 S13 1.39E+00 0.00E+00 1.53E-04 -9.82E-07 2.99E-07 -1.47E-08 4.94E-10

[0158] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are shown in FIGS. 4-1 to 4-6, respectively. Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 30

[0159] Figure 31 The field curvature curve of Example 4 is shown, which represents the curvature of the meridional image surface and sagittal image surface of light rays of different wavelengths, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.02 mm to 0.06 mm, which shows that the optical lens can well correct the field curvature.

[0160] Figure 32 The F-Tanθ distortion curve of Example 4 is shown, which represents the F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging surface, the horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within 2.5%, and the image compression in the edge angle region is relatively flat, which effectively improves the clarity of the expanded image.

[0161] Figure 33 The relative illumination curve of Example 4 is shown, which represents the relative illumination value of 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 70% at the maximum half field angle, which shows that the optical lens has good relative illumination.

[0162] Figure 34 The MTF (modulation transfer function) curve of Example 4 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies under each field of view, the horizontal axis represents the 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 0.5 within the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, which has good imaging quality and good detail resolution ability in both low and high frequency cases.​​​​​​

[0163] Figure 35 The axial aberration curve of the optical lens of Example 4 is shown in FIG. 4, which represents the aberration of the optical axis at the imaging plane at each wavelength, and 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 shift of the axial aberration is controlled within -20 μm ~ 10 μm, which indicates that the optical lens can well correct the axial aberration.

[0164] Figure 30 The axial aberration curve of the optical lens of Example 4 is shown in FIG. 4, which represents the aberration of the optical axis at the imaging plane at each wavelength, and 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 shift of the axial aberration is controlled within -20 μm ~ 10 μm, which indicates that the optical lens can well correct the axial aberration.

[0165] Example 5

[0166] Please refer to Figure 31 , which is a schematic structural diagram of the optical lens provided in Example 5 of the present application. The optical lens of the present embodiment is substantially the same as that of Example 1, and the difference mainly lies in that the stop ST is arranged between the third lens L3 and the fourth lens L4, and the optical parameters such as the radius of curvature, the asphericity coefficient and the thickness of each lens surface are different.

[0167] The related parameters of each lens in the optical lens of Example 5 are shown in Table 5-1.

[0168] Table 5-1

[0169]

[0170] The surface type parameters of the aspheric lenses of the optical lens of Example 5 are shown in Table 5-2.

[0171] Table 5-2

[0172] Figure 32 K A B C D E F S1 6.02E-01 0.00E+00 9.37E-06 3.35E-06 2.84E-08 -9.99E-10 5.82E-12 S2 -2.12E+00 0.00E+00 7.15E-05 3.05E-06 1.37E-08 -1.08E-10 -5.75E-13 S5 5.02E+01 0.00E+00 2.47E-05 1.46E-07 -1.50E-08 4.80E-10 -6.13E-12 S6 -7.44E-01 0.00E+00 -6.49E-05 -4.46E-07 4.71E-08 -9.68E-10 1.04E-11 S12 -1.08E+00 0.00E+00 5.35E-05 -8.57E-07 7.80E-08 -4.69E-09 1.04E-10 S13 6.13E-01 0.00E+00 1.32E-04 -2.00E-06 1.10E-07 -8.54E-09 2.37E-10

[0173] In the present embodiment, the field curvature curve, the F-Tanθ distortion curve, the relative luminance curve, the MTF curve, the axial aberration curve and the axial aberration curve of the optical lens are shown in FIGS. Figure 33 、 Figure 34 、 Figure 35 、 ​ 、 ​ 、 ​ .

[0174] ​The field curvature curve of Example 5 is shown, which represents 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 of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.04 mm to 0.02 mm, indicating that the optical lens can effectively correct the field curvature.

[0175] ​ The F-Tanθ distortion curves for Example 5 are shown, representing the F-Tanθ distortion of different wavelengths of light at different image heights on the imaging plane. The horizontal axis represents F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -0.2% to 0.4%, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0176] ​ The relative illumination curves for Example 5 are shown, representing the relative illumination values ​​at different field-of-view 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.

[0177] ​ The MTF (Modulation Transfer Function) curve of Example 5 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.5 throughout the entire field of view. Within the range of 0–160 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0178] ​ The axial aberration curve of Example 5 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane. 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 axial aberration offset is controlled within ±10μm, indicating that the optical lens can effectively correct axial aberration.

[0179] ​The vertical color aberration curve of embodiment 5 is shown, which represents the color aberration of each wavelength at different image heights on the imaging plane relative to the central wavelength (0.55 μm), the horizontal axis represents the vertical color aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. As can be seen from the figure, the vertical color aberration of the longest wavelength and the shortest wavelength is controlled within -1 μm ~ 2 μm, which shows that the optical lens can well correct the color aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0180] Referring to Table 6, the optical characteristics corresponding to each of the above embodiments are shown, including the effective focal length f, the total optical length TTL, the aperture value FNO, the real image height ih corresponding to the maximum half field angle, the chief ray angle CRA, the maximum field angle FOV of the optical lens, and the numerical value corresponding to each conditional expression in each embodiment.

[0181] Table 6

[0182]

[0183]

[0184] In summary of the above embodiments, the optical lens provided by the present application improves the imaging quality of the optical lens, reduces aberration, improves the imaging quality of the optical lens, and realizes the effect of having long focal length, small size, low cost, high resolution, and being able to be used in weak light and harsh environment.

[0185] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0186] The above-described embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but cannot be understood as limiting the scope of the patent of the present application. It should be noted that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An optical lens, in total seven pieces of lenses, characterized in that, In order from the object side to the imaging plane along the optical axis, the optical lens comprises in sequence: a first lens with positive refractive power; a second lens with positive refractive power, the object side surface of which is concave, and the image side surface of which is convex; a third lens with positive refractive power, both the object side surface and the image side surface of which are convex; a fourth lens with positive refractive power, both the object side surface and the image side surface of which are convex; a fifth lens with negative refractive power, both the object side surface and the image side surface of which are concave; a sixth lens with positive refractive power, the object side surface of which is convex, and the image side surface of which is concave; a seventh lens with positive refractive power, the object side surface of which is convex, and the image side surface of which is concave; The total optical length TTL of the optical lens and the effective focal length f satisfy: 1.87 ≤ TTL / f < 2.

5.

2. The optical lens of claim 1, wherein, The object side surface curvature radius R1 of the first lens and the image side surface curvature radius R2 of the first lens satisfy: |(R1+R2) / (R1-R2)|>20.

0.

3. The optical lens of claim 1, wherein, The object side surface curvature radius R3 of the second lens and the image side surface curvature radius R4 of the second lens satisfy: (R3+R4) / (R3-R4)>10.

0.

4. The optical lens of claim 1, wherein, The object side surface curvature radius R11 of the sixth lens and the image side surface curvature radius R12 of the sixth lens satisfy: |(R11+R12) / (R11-R12)|>10.

0.

5. The optical lens of claim 1, wherein, The object side surface curvature radius R13 of the seventh lens and the image side surface curvature radius R14 of the seventh lens satisfy: |(R13+R14) / (R13-R14)|>10.

0.

6. The optical lens of claim 1, wherein, The total optical length TTL of the optical lens and the sum ∑CT of the center thicknesses of the first lens to the seventh lens along the optical axis respectively satisfy: ∑CT / TTL>0.

55.

7. The optical lens of claim 1, wherein, The effective focal length f of the optical lens, the maximum field of view FOV and the real image height ih corresponding to the maximum half field of view angle satisfy: 0.95<ih / (f×tan(FOV / 2))<1.

05.

8. The optical lens of claim 1, wherein, The maximum field of view FOV of the optical lens and the aperture value FNO satisfy: 12.0°<FOV / FNO<25.0°.

9. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the optical back focal length BFL satisfy: BFL / f>0.

25.

10. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: f1 / f>15.0.

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