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 surface of the first lens is a concave surface; a second lens with positive optical power, wherein an image side surface of the second lens is a convex surface; a third lens with positive optical power, wherein both an object side surface and an image side surface of the third lens are convex surfaces; a fourth lens with positive optical power, wherein both an object side surface and an image side surface of the fourth lens are convex surfaces; a fifth lens with negative optical power, wherein both an object side surface and an image side surface of the fifth lens are concave surfaces; and a sixth lens with positive optical power, wherein an object side surface of the sixth lens is a concave surface and an image side surface of the sixth lens is a convex surface; and the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy 10.0 < f6 / f < 35.0. 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 shape 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 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. It collects environmental information through various lenses and sensors to ensure the safety of drivers. In addition to the requirements of optical lenses for ADAS systems, such as light and thin shape, high pixel, high resolution and other characteristics, the optical lenses also need to be able 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 comprises six lenses in order 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 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 positive focal power, the object side surface of which is concave and the image side surface of which is convex;

[0012] The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 10.0 < f6 / f < 35.0.

[0013] Further preferably, the object side surface sagittal half-flux radius height Sag11 of the sixth lens and the object side surface half-flux radius d11 satisfy: -0.35 < Sag11 / d11 < -0.15, and the image side surface sagittal half-flux radius height Sag12 of the sixth lens and the image side surface half-flux radius d12 satisfy: -0.28 < Sag12 / d12 < -0.18.

[0014] Further preferably, 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 satisfy: 0.4 < (CT2+CT3) / TTL < 0.55.

[0015] Further preferably, 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 satisfy: 0.4 < (CT2+CT3) / TTL < 0.55.

[0016] Further preferably, the total optical length TTL of the optical lens and the effective focal length f satisfy: 4.5 < TTL / f < 6.5.

[0017] Further preferably, the total optical length TTL of the optical lens and the effective focal length f satisfy: 4.5 < TTL / f < 6.5.

[0018] Further preferably, the total optical length TTL of the optical lens and the effective focal length f satisfy: 4.5 < TTL / f < 6.5.

[0019] Further preferably, the total optical length TTL of the optical lens and the effective focal length f satisfy: 4.5 < TTL / f < 6.5.

[0020] Further preferably, the total optical length TTL of the optical lens and the effective focal length f satisfy: 4.5 < TTL / f < 6.5.

[0021] 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

[0022] 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:

[0023] Figure 1 FIG. 1 is a structure diagram of an optical lens according to an embodiment of the present application.

[0024] Figure 2 FIG. 3 is a field curvature curve of the optical lens according to the embodiment of the present application.

[0025] Figure 3 FIG. 5 is an F-Tanθ distortion curve of the optical lens according to the embodiment of the present application.

[0026] Figure 4Relative illuminance curve of the optical lens in Embodiment 1 of the present application.

[0027] Figure 5 MTF curve of the optical lens in Embodiment 1 of the present application.

[0028] Figure 6 Axial aberration curve of the optical lens in Embodiment 1 of the present application.

[0029] Figure 7 Vignetting curve of the optical lens in Embodiment 1 of the present application.

[0030] Figure 8 Structure diagram of the optical lens in Embodiment 2 of the present application.

[0031] Figure 9 Curvature of field curve of the optical lens in Embodiment 2 of the present application.

[0032] Figure 10 F-Tanθ distortion curve of the optical lens in Embodiment 2 of the present application.

[0033] Figure 11 Relative illuminance curve of the optical lens in Embodiment 2 of the present application.

[0034] Figure 12 MTF curve of the optical lens in Embodiment 2 of the present application.

[0035] Figure 13 Axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0036] Figure 14 Vignetting curve of the optical lens in Embodiment 2 of the present application.

[0037] Figure 15 Structure diagram of the optical lens in Embodiment 3 of the present application.

[0038] Figure 16 Curvature of field curve of the optical lens in Embodiment 3 of the present application.

[0039] Figure 17 F-Tanθ distortion curve of the optical lens in Embodiment 3 of the present application.

[0040] Figure 18 Relative illuminance curve of the optical lens in Embodiment 3 of the present application.

[0041] Figure 19 MTF curve of the optical lens in Embodiment 3 of the present application.

[0042] Figure 20 Axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0043] Figure 21 A curve graph of the optical lens in Example 3 of the present application is a sagittal chromatic aberration curve.

[0044] Figure 22 A structure diagram of the optical lens in Example 4 of the present application is shown.

[0045] Figure 23 A curve graph of the optical lens in Example 4 of the present application is a field curvature curve.

[0046] Figure 24 A F-Tanθ distortion curve of the optical lens in Example 4 of the present application is shown.

[0047] Figure 25 A relative luminance curve graph of the optical lens in Example 4 of the present application is shown.

[0048] Figure 26 A MTF curve graph of the optical lens in Example 4 of the present application is shown.

[0049] Figure 27 An axial aberration curve graph of the optical lens in Example 4 of the present application is shown.

[0050] Figure 28 A sagittal chromatic aberration curve of the optical lens in Example 4 of the present application is shown.

[0051] The following detailed description will further describe the present application with reference to the above-described drawings. DETAILED DESCRIPTION

[0052] 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.

[0053] 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 of the features. Thus, the first lens discussed below can also be referred to as a second lens or a third lens without departing from the teachings of the present application.

[0054] 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 aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0055] 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 image plane is referred to as the image side surface of the lens.

[0056] 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, the use of "may" means "one or more embodiments of the present application". And the term "exemplary" is intended to refer to an example or illustration.

[0057] 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.

[0058] 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 embodiments.

[0059] The optical lens of the embodiments of the present application comprises, in order from the object side to the image 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.

[0060] 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 image side surface is convex. The third lens can have a positive focal power, and both its object side surface and image side surface are convex. The fourth lens can have a positive focal power, and both its object side surface and image side surface are convex. The fifth lens can have a negative focal power, and both its object side surface and image side surface are concave. The sixth lens can have a positive focal power, and its object side surface is concave and its image side surface is convex.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 10.0 < f6 / f < 35.0. Satisfying the above range, the eccentricity sensitivity of the light beam imaging is reduced, and the aberration of the optical lens is corrected to have better imaging quality.

[0062] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f satisfy: 4.5 < TTL / f < 6.5. Satisfying the above range, the length of the optical lens is effectively limited, which is beneficial to miniaturization of the optical lens.

[0063] In some embodiments, the effective focal length f of the optical lens, the real image height ih corresponding to the maximum half field of view of the optical lens, and the maximum field of view FOV satisfy: 0.6 < ih / (f*Tan(FOV / 2)) < 0.8. Satisfying the above range, the optical lens can have the characteristics of small distortion and large target surface.

[0064] In some embodiments, the effective focal length f of the optical lens and the optical back focal length BFL satisfy: 0.6 < BFL / f < 0.9. Satisfying the above range, space is reserved for installation and focusing of the optical element, avoiding interference when assembling the optical lens and the optical element.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.5 < f1 / f < -1.0. Satisfying the above range, the first lens can have appropriate negative focal power, which is beneficial to collecting as much edge field of view light as possible into the rear optical lens, realizing large angle light collection, and achieving a large field of view.

[0066] 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 focal power, which is beneficial to improve the light convergence ability of the optical lens, while balancing various aberrations generated by the optical lens, and improving the imaging quality of the optical lens.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 2.0 < f3 / f < 3.0. Satisfying the above range, the third lens can have appropriate positive focal power, converging light while reducing the light deflection angle, allowing smooth transition of the light path, while balancing various aberrations generated by the optical lens, and 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 f4 of the fourth lens satisfy: 1.0 < f4 / f < 2.0. Satisfying the above range, the fourth lens can have appropriate positive refractive power, converge light rays while reducing the light ray deflection angle, make the light ray trend transition smoothly, and balance various aberrations generated by the optical lens to improve the imaging quality of the optical lens.

[0069] 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.

[0070] In some embodiments, the sagittal height Sag11 of the half light entrance radius of the object side surface of the sixth lens and the half light entrance radius d11 of the object side surface satisfy: -0.35 < Sag11 / d11 < -0.15, and the sagittal height Sag12 of the half light entrance radius of the image side surface of the sixth lens and the half light entrance radius d12 of the image side surface satisfy: -0.28 < Sag12 / d12 < -0.18. Satisfying the above range can reduce the incidence angle of light on the photosensitive chip, effectively correct off-axis aberration, and improve the imaging quality.

[0071] In some embodiments, the half light entrance radius d1 of the object side surface 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. Satisfying the above range can ensure the balance between the size of the optical lens, the field angle, and the image plane.

[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 can effectively inhibit the phenomenon that the incident light beam is greatly expanded after being diverged by the first lens, without the need to excessively strengthen 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 cemented to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the sensitivity of the optical lens to decentration, balance the aberration of the optical lens, and improve the imaging quality of the optical lens. In addition, the cemented lens can reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

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

[0075]

[0076] wherein z is the distance of the curved surface to the vertex of the curved surface in the direction of the optical axis, h is the distance of the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the coefficient of the quadratic curved surface, and A, B, C, D, E, and F are the coefficients of the second-order, fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order curved surfaces, 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 merely the preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments only, and any change, substitution, combination, or simplification made without departing from the innovative points of the application should be regarded as equivalent replacement, and should be 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 Embodiment 1 of the application. The optical lens comprises, along the optical axis from the object side to the imaging surface, a first lens L1, a stop 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 both the object side surface S1 and the image side surface S2 thereof are concave surfaces;

[0081] The stop ST;

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

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

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

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

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

[0087] The sixth lens L6 has a negative focal power, and the object side surface S10 thereof is a concave surface, and the image side surface S11 thereof is a convex surface;

[0088] The object side S12 and the image side S13 of the filter G1 are both planar surfaces;

[0089] The object side S14 and the image side S15 of the protective glass G2 are both planar surfaces;

[0090] The imaging surface S16 is a planar surface.

[0091] The related parameters of each lens in the optical lens in Embodiment 1 are shown in Table 1-1.

[0092] Table 1-1

[0093]

[0094] The surface type parameters of the aspherical lens of the optical lens in Embodiment 1 are shown in Table 1-2.

[0095] Table 1-2

[0096] Face number K A B C D E F S1 -4.02E+01 0.00E+00 3.67E-03 -2.70E-04 1.28E-05 -3.60E-07 4.40E-09 S2 -1.59E+00 0.00E+00 9.18E-03 -7.25E-04 5.94E-05 -3.04E-06 7.23E-08 S10 -4.99E+01 0.00E+00 -1.37E-03 -3.36E-05 7.81E-07 5.24E-09 -1.01E-10 S11 -4.97E+01 0.00E+00 -7.83E-04 -3.28E-05 1.34E-06 -1.84E-08 1.12E-10

[0097] 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 chromatic aberration curve of the optical lens are shown in FIGS. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7

[0098] Figure 2 The field curvature curve of Embodiment 1 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.

[0099] Figure 3 The F-Tanθ distortion curve of Embodiment 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 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 -6%~0, the image compression in the edge angle region is relatively flat, and the clarity of the expanded image is effectively improved.

[0100] Figure 4 ​The relative luminance curve of the embodiment 1 is shown, which represents the relative luminance values of different field angles on the imaging plane, 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.

[0101] 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 0.4 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 capability in the case of low frequency and high frequency.

[0102] 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 ±24 μm, which indicates that the optical lens can better correct the axial aberration.

[0103] Figure 7 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 ±24 μm, which indicates that the optical lens can better correct the axial aberration.

[0104] Embodiment 2

[0105] Please refer to Figure 8 , which is a structural schematic diagram of the optical lens provided in the embodiment 2 of the present application. Compared with the embodiment 1, the main difference is that the optical parameters such as the curvature radius of each lens surface, the lens thickness, and the aspheric surface type parameter are different.

[0106] The related parameters of each lens in the optical lens in the embodiment 2 are shown in Table 2-1.

[0107] Table 2-1

[0108]

[0109] The surface type parameters of the aspheric lens of the optical lens in the embodiment 2 are shown in Table 2-2.

[0110] Table 2-2

[0111] Face number K A B C D E F S1 -2.43E+01 0.00E+00 2.03E-03 -9.00E-05 2.97E-06 -6.10E-08 5.53E-10 S2 -5.08E+01 0.00E+00 6.22E-03 -2.29E-04 1.62E-05 -6.76E-07 2.48E-08 S10 -4.99E+01 0.00E+00 -3.64E-04 -2.56E-06 -1.34E-07 3.42E-09 -9.74E-11 S11 3.36E+01 0.00E+00 -4.56E-05 -7.25E-06 2.92E-08 -3.31E-09 5.71E-11

[0112] In this embodiment, the field curvature curve, F-Tanθ distortion curve, relative illumination curve, MTF curve, axial aberration curve, and transverse aberration curve of the optical lens are shown in FIGS. 1-4, respectively. Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 、 Figure 14

[0113] Figure 9 The field curvature curve of Example 2 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 -0.04 mm~0.05 mm, which shows that the optical lens can well correct the field curvature.

[0114] Figure 10 The F-Tanθ distortion curve of Example 2 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 -8%~0, the image compression in the edge angle region is relatively flat, and the clarity of the expanded image is effectively improved.

[0115] Figure 11 The relative illumination curve of Example 2 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 90% at the maximum half field angle, which shows that the optical lens has good relative illumination.

[0116] Figure 12 The MTF (Modulation Transfer Function) curve of Example 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 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 0.4 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 frequency and high frequency cases.

[0117] Figure 13 ​The axial aberration curve of the optical lens of embodiment 2 is shown in FIG. 2, 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 shift of the axial aberration is controlled within -12 μm ~ 15 μm, which indicates that the optical lens can well correct the axial aberration.

[0118] Figure 14 The axial aberration curve of the optical lens of embodiment 2 is shown in FIG. 2, 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 shift of the axial aberration is controlled within -12 μm ~ 15 μm, which indicates that the optical lens can well correct the axial aberration.

[0119] Embodiment 3

[0120] Please refer to Figure 15 , which is a structural schematic diagram of the optical lens provided in embodiment 3 of the present application. Compared with embodiment 1, the difference of the present embodiment is that the object side S1 of the first lens L1 is a convex surface, the object side S3 of the second lens L2 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.

[0121] The related parameters of each lens in the optical lens of embodiment 3 are shown in Table 3-1.

[0122] Table 3-1

[0123]

[0124]

[0125] The surface type parameters of the aspheric lens of the optical lens of embodiment 3 are shown in Table 3-2.

[0126] Table 3-2

[0127] Face number K A B C D E F S1 4.96E+01 0.00E+00 8.98E-04 -1.20E-04 6.74E-06 -2.11E-07 2.83E-09 S2 -8.91E+00 0.00E+00 8.15E-03 -7.32E-04 5.95E-05 -3.02E-06 6.99E-08 S10 -5.47E+00 0.00E+00 -1.96E-03 -5.85E-05 -2.15E-06 3.80E-07 -7.79E-09 S11 -5.15E+00 0.00E+00 -1.08E-03 -6.92E-05 2.47E-06 7.18E-08 -2.05E-09

[0128] 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 16 、 Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 、 Figure 21

[0129] Figure 16 ​The field curvature curve of embodiment 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 -0.05mm~0.02mm, which shows that the optical lens can well correct the field curvature.

[0130] Figure 17 The F-Tanθ distortion curve of embodiment 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 -6%~0, the image compression in the edge angle region is relatively flat, and the clarity of the expanded image is effectively improved.

[0131] Figure 18 The relative luminance curve of embodiment 3 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 70% at the maximum half field angle, which shows that the optical lens has good relative luminance.

[0132] Figure 19 The MTF (Modulation Transfer Function) curve of embodiment 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 embodiment is above 0.3 within the full field of view, and within the range of 0~160lp / 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 frequency and high frequency conditions.

[0133] Figure 20 The axial aberration curve of embodiment 3 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~20μm, which shows that the optical lens can well correct the axial aberration.

[0134] Figure 21The vertical color aberration curve of embodiment 3 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 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.

[0135] Embodiment 4

[0136] 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 difference is that the object side S1 of the first lens L1 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.

[0137] The related parameters of each lens in the optical lens in embodiment 4 are shown in Table 4-1.

[0138] Table 4-1

[0139]

[0140]

[0141] The surface type parameters of the aspheric lens of the optical lens in embodiment 4 are shown in Table 4-2.

[0142] Table 4-2

[0143] Face number K A B C D E F S1 -5.01E+01 0.00E+00 2.56E-03 -2.45E-04 1.26E-05 -3.72E-07 4.73E-09 S2 -7.25E+00 0.00E+00 9.45E-03 -6.95E-04 5.18E-05 -2.59E-06 6.71E-08 S10 -5.40E+01 0.00E+00 -2.42E-03 2.11E-05 -7.17E-06 3.97E-07 -5.47E-09 S11 -1.02E+01 0.00E+00 -8.53E-04 -2.93E-05 -2.31E-08 6.28E-08 -9.93E-10

[0144] 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 vertical color aberration curve of the optical lens are shown in Figure 23 、 Figure 24 、 Figure 25 、 Figure 26 、 Figure 27 、 Figure 28 respectively.

[0145] Figure 23 The field curvature curve of embodiment 4 is shown, which represents the bending degree of light rays of different wavelengths on the meridional image plane and the sagittal image plane, 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 plane and the sagittal image plane is controlled within -0.04 mm ~ 0.06 mm, which shows that the optical lens can well correct the field curvature.

[0146] Figure 24The 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 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 -3%~0, the image compression in the edge angle region is relatively gentle, and the clarity of the expanded image is effectively improved.

[0147] Figure 25 The relative illumination curve of embodiment 4 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 70% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0148] Figure 26 The MTF (Modulation Transfer Function) curve of embodiment 4 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.

[0149] Figure 27 The axial aberration curve of embodiment 4 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 -30 μm~24 μm, indicating that the optical lens can better correct the axial aberration.

[0150] Figure 28 The sagittal chromatic aberration curve of embodiment 4 is shown, which represents the chromatic 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 sagittal chromatic 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 sagittal chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1 μm~3 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.

[0151] Please refer to Table 5, the optical properties 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 of view angle, the chief ray angle CRA, and the maximum field of view angle FOV of the optical lens, and the values corresponding to each condition in each embodiment.

[0152] Table 5

[0153]

[0154]

[0155] 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.

[0156] In the description of the present specification, the description referring to 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.

[0157] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to 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, six pieces of lenses in total, characterized in that, In order from the object side to the imaging surface along the optical axis, the optical lens comprises in sequence: a first lens with negative refractive power, an image-side surface of which is a concave surface; a second lens with positive refractive power, an image-side surface of which is a convex surface; a third lens with positive refractive power, both an object-side surface and an image-side surface of which are convex surfaces; a fourth lens with positive refractive power, both an object-side surface and an image-side surface of which are convex surfaces; a fifth lens with negative refractive power, both an object-side surface and an image-side surface of which are concave surfaces; a sixth lens with positive refractive power, an object-side surface of which is a concave surface and an image-side surface of which is a convex surface; The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 10.0 < f6 / f ≤ 29.20; The effective focal length f of the optical lens and the optical back focal length BFL satisfy: 0.6 < BFL / f < 0.

9.

2. The optical lens of claim 1, wherein, The optical lens satisfies one or more of the following conditional expressions: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 2.0 < f3 / f < 3.0; The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.0 < f4 / f < 2.0; 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.

3. The optical lens of claim 1, wherein, The object-side surface sagittal height Sag11 of the sixth lens and the object-side surface half-field diameter d11 satisfy: -0.35 < Sag11 / d11 < -0.15, and the image-side surface sagittal height Sag12 of the sixth lens and the image-side surface half-field diameter d12 satisfy: -0.28 < Sag12 / d12 < -0.

18.

4. The optical lens of claim 1, wherein, The object-side surface half-field diameter 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.

5. The optical lens of claim 1, wherein, 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.

6. The optical lens of claim 1, wherein, The total optical length TTL of the optical lens and the effective focal length f satisfy: 4.5 < TTL / f < 6.

5.

7. The optical lens of claim 1, wherein, 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: 0.6 < ih / (f*Tan(FOV / 2)) < 0.

8.

8. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 11.45 ≤ f6 / f ≤ 29.20; The effective focal length f of the optical lens and the optical back focal length BFL satisfy: 0.63 ≤ BFL / f ≤ 0.

87.

9. 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: -1.5 < f1 / f < -1.

0.

10. The optical lens of claim 1, wherein, 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.

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