Optical lens

Abstract

The application provides an optical lens, which comprises six lenses in sequence along an optical axis from an object side to an imaging surface, and the six lenses comprise: a first lens with negative optical power, wherein an image side of the first lens is a concave surface; a second lens with positive optical power, wherein an object side of the second lens is a concave surface, and an image side of the second lens is a convex surface; a third lens with positive optical power, wherein both the object side and the image side of the third lens are convex surfaces; a fourth lens with positive optical power, wherein both the object side and the image side of the fourth lens are convex surfaces; a fifth lens with negative optical power, wherein both the object side and the image side of the fifth lens are concave surfaces; and a sixth lens with negative optical power; and the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -30.0 < f6 / f < -6.0. 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 by reasonably configuring the surface type of each lens and reasonably matching the optical 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 increasingly used in intelligent driving, and vehicle optical lenses are continuously improving in the automotive industry.

[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. In addition to the requirements of optical lenses for the existing ADAS system, such as light and thin shape, high pixel, high resolution and other characteristics, the optical lens is also required to clearly image under low illumination conditions, so it is necessary to develop an optical lens with good imaging effect. SUMMARY

[0004] In view of the above problems, the purpose of the present application is to provide an optical lens with excellent imaging quality.

[0005] The present application provides an optical lens, which has a total of six lenses, and includes, along the optical axis from the object side to the imaging surface:

[0006] The first lens with negative focal power, the image side surface of which is concave;

[0007] The second lens with positive focal power, the object side surface of which is concave, and the image side surface of which is convex;

[0008] The third lens with positive focal power, both the object side surface and the image side surface of which are convex;

[0009] The fourth lens with positive focal power, both the object side surface and the image side surface of which are convex;

[0010] The fifth lens with negative focal power, both the object side surface and the image side surface of which are concave;

[0011] The sixth lens with negative focal power;

[0012] The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -30.0 < f6 / f < -6.0.

[0013] Further preferably, 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)| < 2.2.

[0014] It is further preferred that the object-side half light entrance radius d1 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 satisfy: 0.72 < d1 / ih / Tan(FOV / 2) < 0.85.

[0015] It is further preferred that the sagittal height Sag11 and the object-side half light entrance radius d11 of the sixth lens satisfy: -0.4 < Sag11 / d11 < 0, and the sagittal height Sag12 and the image-side half light entrance radius d12 of the sixth lens satisfy: -0.3 < Sag12 / d12 < 0.

[0016] It is further preferred that the central thickness CT2 of the second lens along the optical axis and the central thickness CT3 of the third lens along the optical axis and the total optical length TTL of the optical lens satisfy: 0.4 < (CT2+CT3) / TTL < 0.55.

[0017] It is further preferred that the total optical length TTL of the optical lens and the effective focal length f satisfy: TTL / f < 5.0.

[0018] It is further preferred that 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: 0.65 < ih / (f*Tan(FOV / 2)) < 0.7.

[0019] It is further preferred that the effective focal length f of the optical lens and the optical back focal length BFL satisfy: 0.68 < BFL / f < 0.8.

[0020] The optical lens provided by the present application improves the imaging quality of the optical lens, reduces aberration, and improves the imaging quality of the optical lens by reasonable configuration of each lens surface and reasonable matching of optical power. BRIEF DESCRIPTION OF DRAWINGS

[0021] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:

[0022] Figure 1 FIG. 1 is a structure diagram of an optical lens according to an embodiment of the present application.

[0023] Figure 2 FIG. 2 is a field curvature curve of the optical lens according to the embodiment of the present application.

[0024] Figure 3 FIG. 3 is an F-Tanθ distortion curve of the optical lens according to the embodiment of the present application.

[0025] Figure 4 FIG. 4 is a relative luminance curve of the optical lens according to the embodiment of the present application.

[0026] Figure 5 MTF curve of the optical lens in Embodiment 1 of the present application.

[0027] Figure 6 Axial aberration curve of the optical lens in Embodiment 1 of the present application.

[0028] Figure 7 Vignetting curve of the optical lens in Embodiment 1 of the present application.

[0029] Figure 8 Structure diagram of the optical lens in Embodiment 2 of the present application.

[0030] Figure 9 Curvature of field curve of the optical lens in Embodiment 2 of the present application.

[0031] Figure 10 F-Tanθ distortion curve of the optical lens in Embodiment 2 of the present application.

[0032] Figure 11 Relative illumination curve of the optical lens in Embodiment 2 of the present application.

[0033] Figure 12 MTF curve of the optical lens in Embodiment 2 of the present application.

[0034] Figure 13 Axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0035] Figure 14 Vignetting curve of the optical lens in Embodiment 2 of the present application.

[0036] Figure 15 Structure diagram of the optical lens in Embodiment 3 of the present application.

[0037] Figure 16 Curvature of field curve of the optical lens in Embodiment 3 of the present application.

[0038] Figure 17 F-Tanθ distortion curve of the optical lens in Embodiment 3 of the present application.

[0039] Figure 18 Relative illumination curve of the optical lens in Embodiment 3 of the present application.

[0040] Figure 19 MTF curve of the optical lens in Embodiment 3 of the present application.

[0041] Figure 20 Axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0042] Figure 21 A curve of the lateral chromatic aberration of the optical lens in Embodiment 3 of the present application.

[0043] Figure 22 A structure diagram of the optical lens in Embodiment 4 of the present application.

[0044] Figure 23 A curve of the field curvature of the optical lens in Embodiment 4 of the present application.

[0045] Figure 24 An F-Tanθ distortion curve of the optical lens in Embodiment 4 of the present application.

[0046] Figure 25 A relative luminance curve of the optical lens in Embodiment 4 of the present application.

[0047] Figure 26 An MTF curve of the optical lens in Embodiment 4 of the present application.

[0048] Figure 27 An axial aberration curve of the optical lens in Embodiment 4 of the present application.

[0049] Figure 28 A curve of the lateral chromatic aberration of the optical lens in Embodiment 4 of the present application.

[0050] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0051] 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 descriptions of embodiments of the present application and are not intended in any way to limit the scope of the present application. 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.

[0052] It is to be noted that, in the present specification, the expressions first, second, third and the like are used only to distinguish one feature from another feature, and do not indicate 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.

[0053] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for the sake of explanation. Specifically, the shape of the spherical surface or the aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0054] In the present disclosure, 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 imaging plane is referred to as the image side surface of the lens.

[0055] It should also be understood that the use of the terms "including", "including", "having", "containing", and / or "containing" when used in this specification means that the presence of the stated features, elements and / or components, but does not exclude 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, not individual elements of the list. In addition, when describing embodiments of the present application, "may" means "one or more embodiments of the present application". And the term "exemplary" is intended to refer to an example or illustration.

[0056] 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 the present 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 art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0057] 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 conjunction with the embodiments.

[0058] The optical lens of the embodiments of the present application comprises, in order from the object side to the imaging plane along the optical axis: a first lens, a diaphragm, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a filter and a protective glass.

[0059] In some embodiments, the first lens can have a negative focal power, and its image side surface is concave. The second lens can have a positive focal power, and its object side surface is concave and its image side surface is convex. The third lens can have a positive focal power, and its object side surface and image side surface are both convex. The fourth lens can have a positive focal power, and its object side surface and image side surface are both convex. The fifth lens can have a negative focal power, and its object side surface and image side surface are both concave. The sixth lens has a negative focal power.

[0060] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -30.0 < f6 / f < -6.0. Satisfying the above range, the sixth lens can have appropriate negative refractive power, which is conducive to increasing the imaging area of the optical lens, and can optimize the chromatic aberration of the optical lens, and improve the imaging quality of the optical lens.

[0061] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f satisfy: TTL / f < 5.0. Satisfying the above range, the length of the optical lens is effectively limited, which is conducive to realizing the miniaturization of the optical lens.

[0062] In some embodiments, 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: 0.65 < ih / (f*Tan(FOV / 2)) < 0.7. Satisfying the above range, the optical lens can have the characteristics of small distortion and large target surface.

[0063] In some embodiments, the effective focal length f of the optical lens and the optical back focal length BFL satisfy: 0.68 < BFL / f < 0.8. Satisfying the above range, it is conducive to reserving space for the installation and focusing of the optical element, and avoiding interference when assembling the optical lens and the optical element.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.0 < f1 / f < -1.2. Satisfying the above range, the first lens can have appropriate negative refractive power, which is conducive to collecting as much edge field light as possible into the rear optical lens, realizing large-angle light collection, and achieving a large field angle.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 2.0 < f2 / f < 3.5. Satisfying the above range, the second lens can have appropriate positive refractive power, which is conducive to improving the light convergence ability of the optical lens, and can balance various aberrations generated by the optical lens, and improve the imaging quality of the optical lens.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 2.2 < f3 / f < 2.5. Satisfying the above range, the third lens can have appropriate positive refractive power, converge light while reducing the light deflection angle, and make the light trend smooth transition, and can balance various aberrations generated by the optical lens, and improve the imaging quality of the optical lens.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.2 < f4 / f < 1.7. Satisfying the above range, the fourth lens can have appropriate positive refractive power, converge light rays while reducing the light ray deflection angle, smoothly transition the light ray trend, and balance various aberrations generated by the optical lens, thereby improving the imaging quality of the optical lens.

[0068] 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 < -1.0. Satisfying the above range, the fifth lens can have appropriate negative refractive power, which is conducive to balancing the coma generated by the fourth lens and the astigmatism of the lens.

[0069] In some embodiments, the object side surface radius of curvature R1 of the first lens and the image side surface radius of curvature R2 of the first lens satisfy: |(R1-R2) / (R1+R2)| < 2.2. Satisfying the above range, the field of view angle of the optical lens can be increased while balancing the spherical aberration and the field curvature of the optical lens, thereby improving the imaging quality of the optical lens.

[0070] In some embodiments, the object side surface half light entrance radius d1 of the first lens, the real image height ih corresponding to the maximum half field of view angle of the optical lens, and the maximum field of view angle FOV satisfy: 0.72 < d1 / ih / Tan(FOV / 2) < 0.85. Satisfying the above range, the balance between the size and the field of view angle, the image surface of the optical lens can be ensured.

[0071] In some embodiments, the object side surface half light entrance radius sag11 of the sixth lens and the object side surface half light entrance radius d11 satisfy: -0.4 < sag11 / d11 < 0, and the image side surface half light entrance radius sag12 of the sixth lens and the image side surface half light entrance radius d12 satisfy: -0.3 < sag12 / d12 < 0. Satisfying the above range, the incidence angle of the light on the photosensitive chip can be reduced, off-axis aberration can be effectively corrected, and the imaging quality can be improved.

[0072] In some embodiments, the central thickness CT2 of the second lens along the optical axis and the central thickness CT3 of the third lens along the optical axis and the total optical length TTL of the optical lens satisfy: 0.4 < (CT2+CT3) / TTL < 0.55. Satisfying the above range, the phenomenon that the incident light beam is greatly expanded after being diverged by the first lens can be effectively suppressed without excessively strengthening the converging effect of the lens group on the image side of the third lens, thereby preventing the system from generating large aberrations.

[0073] 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, and improve imaging quality of the optical lens; and can also reduce assembly sensitivity of the optical lens, thereby reducing processing difficulty of the optical lens and improving assembly yield of the optical lens.

[0074] In order to make the system have better optical performance, a plurality of aspheric lenses are used in the lens, and each aspheric surface shape of the optical lens satisfies the following equation:

[0075]

[0076] Wherein, z is the distance of the curved surface and 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.

[0077] 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 change, replacement, combination or simplification made without departing from the innovative points of the application should be regarded as equivalent replacement mode, and all are included in the protection scope of the application.

[0078] Embodiment 1

[0079] Please refer to Figure 1 , which is a structural schematic diagram of the optical lens provided in the embodiment 1 of the application, and the optical lens comprises, along the optical axis from the object side to the imaging surface, a first lens L1, a diaphragm ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a filter G1, and a protective glass G2.

[0080] The first lens L1 has a negative focal power, and the object side surface S1 and the image side surface S2 are both concave surfaces;

[0081] The diaphragm ST;

[0082] The second lens L2 has a positive focal power, the object side surface S3 is a concave surface, and the image side surface S4 is a convex surface;

[0083] The third lens L3 has a positive focal power, and the object side surface S5 and the image side surface S6 are both convex surfaces;

[0084] The fourth lens L4 has a positive focal power, and the object side surface S7 and the image side surface S8 are both convex surfaces;

[0085] The fifth lens L5 has negative refractive power, and both the object side S8 and the image side S9 are concave surfaces;

[0086] The fourth lens L4 and the fifth lens L5 form a cemented lens group, that is, the cemented surface of the image side of the fourth lens L4 and the object side of the fifth lens L5 is S8;

[0087] The sixth lens L6 has negative refractive power, and the object side S10 is a convex surface, and the image side S11 is a concave surface; the object side S12 and the image side S13 of the filter G1 are both flat surfaces;

[0088] The object side S14 and the image side S15 of the protective glass G2 are both flat surfaces;

[0089] The imaging surface S16 is a flat surface.

[0090] The related parameters of each lens in the optical lens in Embodiment 1 are shown in Table 1-1.

[0091] Table 1-1

[0092]

[0093] The surface type parameters of the aspherical lens of the optical lens in Embodiment 1 are shown in Table 1-2.

[0094] Table 1-2

[0095] Face number K A B C D E F S1 -2.64E+01 0.00E+00 4.09E-03 -2.77E-04 1.31E-05 -3.74E-07 4.56E-09 S2 -1.50E+01 0.00E+00 9.65E-03 -5.92E-04 4.34E-05 -1.57E-06 3.59E-08 S10 4.75E+01 0.00E+00 -2.70E-03 -6.51E-06 1.20E-06 -1.37E-08 -9.74E-11 S11 -3.04E+01 0.00E+00 -1.62E-03 -1.22E-05 1.67E-06 -3.49E-08 1.69E-10

[0096] In this 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 FIGS. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7

[0097] Figure 2 The field curvature curve of Embodiment 1 is shown, which represents the curvature 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 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-0.06mm-0.03mm, which shows that the optical lens can well correct the field curvature.

[0098] Figure 3 ​The F-Tanθ distortion curve of the embodiment 1 is shown, which represents the F-Tanθ distortion of light rays 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 angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -8%~0, the image compression in the edge angle region is relatively gentle, and the clarity of the expanded image is effectively improved.

[0099] Figure 4 The relative illumination curve of the embodiment 1 is shown, which represents the relative illumination value of 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 80% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0100] Figure 5 The MTF (Modulation Transfer Function) curve of the embodiment 1 is shown, which represents the lens imaging modulation degree of 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 embodiment is above 0.3 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 cases.

[0101] Figure 6 The axial aberration curve of the embodiment 1 is shown, which represents the axial 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 offset of the axial aberration is controlled within -20 μm~8 μm, indicating that the optical lens can better correct the axial aberration.

[0102] Figure 7 The sagittal chromatic aberration curve of the embodiment 1 is shown, which represents the chromatic aberration of each wavelength at different image heights on the imaging plane relative to the center wavelength (0.55 μm). The horizontal axis represents the sagittal chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field angle. As can be seen from the figure, the sagittal chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1 μm~4 μm, indicating 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 plane.

[0103] Embodiment 2

[0104] Please refer to Figure 8Figure 2 shows a structural schematic diagram of the optical lens provided in Embodiment 2 of the present application, which differs from Embodiment 1 mainly in that the optical parameters of the radii of curvature of the surfaces of the lenses, the thicknesses of the lenses, the aspheric surface type parameters, etc. are different.

[0105] The related parameters of the lenses in the optical lens in Embodiment 2 are shown in Table 2-1.

[0106] Table 2-1

[0107]

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

[0109] Table 2-2

[0110] Face number K A B C D E F S1 -4.49E+01 0.00E+00 3.22E-03 -1.86E-04 7.69E-06 -1.94E-07 2.07E-09 S2 -5.30E+01 0.00E+00 7.36E-03 -4.54E-04 3.09E-05 -1.21E-06 2.05E-08 S3 9.77E+00 0.00E+00 -9.20E-04 1.28E-04 -4.21E-05 5.73E-06 -3.12E-07 S4 -7.41E-01 0.00E+00 -2.39E-04 -4.68E-06 1.54E-07 -5.92E-09 8.73E-11 S10 -3.80E+01 0.00E+00 -1.25E-03 8.72E-06 -8.18E-07 3.67E-08 -7.41E-10 S11 7.42E+00 0.00E+00 -1.52E-03 1.74E-05 -6.79E-07 1.62E-08 -3.87E-10

[0111] 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 transverse aberration curve of the optical lens are shown in Figures Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 、 Figure 14 .

[0112] Figure 9 Figure 2 shows the field curvature curve of Embodiment 2, which represents the curvature of the meridional image surface and the 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 -0.06 mm ~ 0, which indicates that the optical lens can well correct the field curvature.

[0113] Figure 10 Figure 2 shows the F-Tanθ distortion curve of Embodiment 2, 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 value (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 -8% ~ 0, the image compression in the edge angle region is relatively flat, and the clarity of the expanded image is effectively improved.

[0114] Figure 11 Figure 2 shows the relative luminance curve of Embodiment 2, 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 indicates that the optical lens has good relative luminance.

[0115] Figure 12 The MTF (Modulation Transfer Function) curve of the embodiment 2 is shown, which represents the lens imaging modulation degree of 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. It can be seen from the figure that the MTF value of the embodiment is above 0.4 in 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 capability in the case of low frequency and high frequency.

[0116] Figure 13 The axial aberration curve of the embodiment 2 is shown, which represents the aberration of the optical axis at the imaging surface at each wavelength, the horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. It can be seen from the figure that the shift amount of the axial aberration is controlled within ±20 μm, which shows that the optical lens can better correct the axial aberration.

[0117] Figure 14 The curve of the embodiment 2 is shown, which represents the color difference of different image heights on the imaging surface at each wavelength relative to the center wavelength (0.55 μm), the horizontal axis represents the vertical color difference value (unit: μm) of each wavelength relative to the center wavelength, and the vertical axis represents the normalized field angle. It can be seen from the figure that the vertical color difference of the longest wavelength and the shortest wavelength is controlled within -1 μm-3 μm, which shows that the optical lens can very well correct the color difference of the edge field of view and the secondary spectrum of the entire image surface.

[0118] Embodiment 3

[0119] Please refer to Figure 15 , which is a structural schematic diagram of the optical lens provided in the embodiment 3 of the present application, and the difference between the embodiment and the embodiment 1 is mainly that the object side S10 of the sixth lens L6 is a concave surface, and the optical parameters such as the curvature radius of each lens surface, the lens thickness, and the aspheric surface type parameter are different.

[0120] The related parameters of each lens in the optical lens in the embodiment 3 are shown in Table 3-1.

[0121] Table 3-1

[0122]

[0123]

[0124] The surface type parameters of the aspheric lens of the optical lens in the embodiment 3 are shown in Table 3-2.

[0125] Table 3-2

[0126] Face number K A B C D E F S1 -2.97E+01 0.00E+00 3.86E-03 -2.78E-04 1.32E-05 -3.80E-07 4.76E-09 S2 -1.69E+01 0.00E+00 9.33E-03 -6.28E-04 5.00E-05 -2.45E-06 6.19E-08 S10 4.99E+01 0.00E+00 -2.44E-03 -1.08E-05 1.41E-06 -1.31E-10 -3.89E-10 S11 5.00E+01 0.00E+00 -1.71E-03 -2.93E-07 1.76E-06 -3.54E-08 1.54E-10

[0127] In the present embodiment, the field curvature curve, the F-Tanθ distortion curve, the relative illumination curve, the MTF curve, the axial aberration curve, and the lateral chromatic aberration curve of the optical lens are shown in FIGS. 14A, 14B, 14C, 14D, 14E, and 14F, respectively. Figure 16 、 Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 、 Figure 21

[0128] Figure 16 The field curvature curve of Example 3 is shown, which represents the curvature 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 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 ±0.04 mm, which shows that the optical lens can well correct the field curvature.

[0129] Figure 17 The F-Tanθ distortion curve of Example 3 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 value (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 -9%~0, the image compression in the edge angle region is relatively flat, and the clarity of the expanded image is effectively improved.

[0130] Figure 18 The relative illumination curve of Example 3 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 80% at the maximum half field angle, which shows that the optical lens has good relative illumination.

[0131] Figure 19 The MTF (Modulation Transfer Function) curve of Example 3 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 0.3 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 both low and high frequency cases.

[0132] Figure 20 ​The axial aberration curve of the optical lens of embodiment 3 is shown in FIG. 3, which represents the axial 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 shift of the axial aberration is controlled within -20 μm-10 μm, which indicates that the optical lens can well correct the axial aberration.

[0133] Figure 21 The axial aberration curve of the optical lens of embodiment 3 is shown in FIG. 3, which represents the axial 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 shift of the axial aberration is controlled within -20 μm-10 μm, which indicates that the optical lens can well correct the axial aberration.

[0134] Embodiment 4

[0135] Please refer to Figure 22 , which is a structural schematic diagram of the optical lens provided in embodiment 4 of the present application. Compared with embodiment 1, the main difference of the present embodiment is that the object side S1 of the first lens L1 is a convex surface, the object side S10 of the sixth lens L6 is a concave surface, the image side S11 of the sixth lens L6 is a convex surface, and the optical parameters such as the curvature radius of each lens surface, the lens thickness, and the aspheric surface type parameters are different.

[0136] The related parameters of each lens in the optical lens of embodiment 4 are shown in Table 4-1.

[0137] Table 4-1

[0138]

[0139]

[0140] The aspheric surface type parameters of the aspheric lenses in the optical lens of embodiment 4 are shown in Table 4-2.

[0141] Table 4-2

[0142] Face number K A B C D E F S1 5.07E+01 0.00E+00 2.62E-03 -2.49E-04 1.31E-05 -4.01E-07 5.34E-09 S2 -8.23E+00 0.00E+00 8.79E-03 -6.47E-04 4.96E-05 -2.54E-06 6.46E-08 S10 -5.74E+01 0.00E+00 -3.14E-03 -5.74E-05 -6.31E-07 2.75E-07 -5.50E-09 S11 -4.95E+01 0.00E+00 -1.88E-03 -9.30E-05 5.44E-06 -6.59E-08 7.07E-11

[0143] In the present embodiment, the field curvature curve, the F-Tanθ distortion curve, the relative illumination curve, the MTF curve, the axial aberration curve, and the axial aberration curve of the optical lens are shown in FIGS. Figure 23 、 Figure 24 、 Figure 25 、 Figure 26 、 Figure 27 、 Figure 28

[0144] ​Figure 23 The field curvature curve of embodiment 4 is shown, which represents the curvature 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 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, which shows that the optical lens can well correct the field curvature.

[0145] Figure 24 The F-Tanθ distortion curve of embodiment 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 value (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 -7%~0, the image compression in the edge angle region is relatively flat, and the clarity of the expanded image is effectively improved.

[0146] Figure 25 The relative luminance curve of embodiment 4 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.

[0147] Figure 26 The MTF (Modulation Transfer Function) curve of embodiment 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 the embodiment is above 0.3 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.

[0148] Figure 27 The axial aberration curve of embodiment 4 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 -30μm~24μm, which shows that the optical lens can well correct the axial aberration.

[0149] Figure 28The vertical color aberration curve of embodiment 4 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 ~ 3 μm, which indicates that the optical lens can very well correct the color aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0150] Referring to Table 5, 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 field angle, the chief ray angle CRA, and the maximum field angle FOV of the optical lens, and the numerical values corresponding to each conditional expression in each embodiment.

[0151] Table 5

[0152]

[0153]

[0154] In summary of the above embodiments, the optical lens provided by the present application improves the imaging quality of the optical lens, reduces aberration, and improves the imaging quality of the optical lens by reasonable configuration of each lens surface and reasonable matching of optical power.

[0155] 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.

[0156] The above-described embodiments only express several embodiments of the present application, which are described in a more specific and detailed manner, but should not 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 within the scope of protection of the present application. Therefore, the scope of protection of the patent of the present application should be subject to the appended claims.

Claims

1. An optical lens comprising six lenses, characterized in that, From the object side to the imaging surface along the optical axis, it successively includes: A first lens with a negative optical power, whose image side is concave; A second lens with a positive optical power, whose object side is concave and image side is convex; A third lens with a positive optical power, whose object side and image side are both convex; A fourth lens with a positive optical power, whose object side and image side are both convex; A fifth lens with a negative optical power, whose object side and image side are both concave; A sixth lens with a negative optical power; The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -30.0 < f6 / f < -6.0; The effective focal length f of the optical 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 < ih / (f * Tan(FOV / 2)) < 0.7; The effective focal length f of the optical lens and the back focal length BFL satisfy: 0.68 < BFL / f < 0.

8.

2. The optical lens according to claim 1, characterized in that, The curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side of the first lens satisfy: |(R1 - R2) / (R1 + R2)| < 2.

2.

3. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.0 < f1 / f < -1.2, and the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 2.0 < f2 / f < 3.

5.

4. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 2.2 < f3 / f < 2.5, and the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.2 < f4 / f < 1.

7.

5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.5 < f5 / f < -1.

0.

6. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter d1 of the object side 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: 0.72 < d1 / ih / Tan(FOV / 2) < 0.

85.

7. The optical lens according to claim 1, characterized in that, The sagitta Sag11 of the clear aperture of the object side of the sixth lens and the clear aperture semi-diameter d11 of the object side satisfy: -0.4 < Sag11 / d11 < 0, and the sagitta Sag12 of the clear aperture of the image side of the sixth lens and the clear aperture semi-diameter d12 of the image side satisfy: -0.3 < Sag12 / d12 < 0.

8. The optical lens according to claim 1, characterized in that, The central thickness CT2 of the second lens along the optical axis and the central thickness CT3 of the third lens along the optical axis and the total optical length TTL of the optical lens satisfy: 0.4 < (CT2 + CT3) / TTL < 0.

55.

9. The optical lens according to claim 1, characterized in that, The total optical length TTL of the optical lens and the effective focal length f satisfy: TTL / f < 5.

0.

10. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -20.1 ≤ f6 / f ≤ -7.87; The effective focal length f of the optical lens, the true image height ih corresponding to the maximum half field angle of the optical lens, and the maximum field angle FOV satisfy: 0.67 ≤ ih / (f * Tan(FOV / 2)) ≤ 0. ​ 11. The optical lens according to claim 1, characterized in that, The total optical length (TTL) and effective focal length (f) of the optical lens satisfy the following condition: 4.80 ≤ TTL / f < 5.0; The object-side radius of curvature R1 and the image-side radius of curvature R2 of the first lens satisfy: 0.94≤|(R1-R2) / (R1+R2)|<2.2.

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