Optical lens

Abstract

The application provides an optical lens, which comprises seven lenses arranged along an optical axis from an object side to an imaging surface in sequence, wherein the first lens has negative optical power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative optical power, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; the third lens has positive optical power; a diaphragm; the fourth lens has positive optical power, the object side surface and the image side surface of the fourth lens are both convex surfaces; the fifth lens has positive optical power, the object side surface and the image side surface of the fifth lens are both convex surfaces; the sixth lens has negative optical power, the object side surface of the sixth lens is a concave surface; and the seventh lens has negative optical power, the object side surface of the seventh lens is a concave surface, and the image side surface of the seventh lens is a convex surface; and the real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD satisfy the condition: 3.0 < IH / EPD < 4.0. The optical lens provided by the application improves the resolving power of the optical lens, reduces aberration, and improves the imaging quality of the optical lens through reasonable configuration of the surface shape of each lens and reasonable matching of 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 combined with sensors to ensure the safety of drivers. In addition to the requirements of light, thin, small shape and high pixel, high resolution of the existing ADAS system surround view lens, the optical lens is 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 seven lenses in sequence from the object side to the imaging surface along the optical axis:

[0006] The first lens with negative focal power, the object side surface is convex, and the image side surface is concave;

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

[0008] The third lens with positive focal power;

[0009] The diaphragm;

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

[0011] The fifth lens with positive focal power, both the object side surface and the image side surface are convex;

[0012] The sixth lens with negative focal power, the object side surface is concave;

[0013] The seventh lens with negative focal power, the object side surface is concave, and the image side surface is convex;

[0014] The real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD satisfy: 3.0<IH / EPD<4.0.

[0015] Further preferably, the total optical length TTL of the optical lens and the effective focal length f satisfy: 6.0<TTL / f<9.0.

[0016] Further preferably, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field of view satisfy: 3.0 < TTL / IH < 5.0.

[0017] Further preferably, the maximum field of view FOV of the optical lens and the aperture value FNO satisfy: 55° < FOV / FNO < 70°.

[0018] Further preferably, the maximum field of view FOV of the optical lens, the real image height IH corresponding to the maximum field of view, and the light passing aperture D1 of the first lens satisfy: 0.7 < D1 / IH / tan(FOV / 2) < 0.98.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.5 < f1 / f < -1.5.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 5.0 < f3 / f < 8.0.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.5 < f4 / f < 2.5.

[0022] Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.5 < f6 / f < -1.1.

[0023] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -11.0 < f7 / f < -9.0.

[0024] The optical lens provided by the present application improves the resolving power 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

[0025] 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:

[0026] Figure 1 FIG. 1 is a structure diagram of an optical lens according to an embodiment of the present application.

[0027] Figure 2 FIG. 2 is a field curvature curve of the optical lens according to the embodiment of the present application.

[0028] Figure 3 FIG. 3 is an MTF curve of the optical lens according to the embodiment of the present application.

[0029] Figure 4 Axial aberration curve of the optical lens in embodiment 1 of the present application.

[0030] Figure 5 Vignetting curve of the optical lens in embodiment 1 of the present application.

[0031] Figure 6 Structure diagram of the optical lens in embodiment 2 of the present application.

[0032] Figure 7 Curvature of field curve of the optical lens in embodiment 2 of the present application.

[0033] Figure 8 MTF curve of the optical lens in embodiment 2 of the present application.

[0034] Figure 9 Axial aberration curve of the optical lens in embodiment 2 of the present application.

[0035] Figure 10 Vignetting curve of the optical lens in embodiment 2 of the present application.

[0036] Figure 11 Structure diagram of the optical lens in embodiment 3 of the present application.

[0037] Figure 12 Curvature of field curve of the optical lens in embodiment 3 of the present application.

[0038] Figure 13 MTF curve of the optical lens in embodiment 3 of the present application.

[0039] Figure 14 Axial aberration curve of the optical lens in embodiment 3 of the present application.

[0040] Figure 15 Vignetting curve of the optical lens in embodiment 3 of the present application.

[0041] Figure 16 Structure diagram of the optical lens in embodiment 4 of the present application.

[0042] Figure 17 Curvature of field curve of the optical lens in embodiment 4 of the present application.

[0043] Figure 18 MTF curve of the optical lens in embodiment 4 of the present application.

[0044] Figure 19 Axial aberration curve of the optical lens in embodiment 4 of the present application.

[0045] Figure 20A curve graph of the optical lens in the embodiment 4 of the present application is shown in FIG. 4.

[0046] Figure 21 A structure diagram of the optical lens in the embodiment 5 of the present application is shown in FIG. 5.

[0047] Figure 22 A curve graph of the field curvature of the optical lens in the embodiment 5 of the present application is shown in FIG. 6.

[0048] Figure 23 A curve graph of the MTF of the optical lens in the embodiment 5 of the present application is shown in FIG. 7.

[0049] Figure 24 A curve graph of the axial aberration of the optical lens in the embodiment 5 of the present application is shown in FIG. 8.

[0050] Figure 25 A curve graph of the optical lens in the embodiment 5 of the present application is shown in FIG. 9.

[0051] The following detailed description will further describe the present application with reference to the above-mentioned 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 drawing 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 the second lens or the 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 convenience in 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 specification, 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", "having", "containing", and / or "containing having" when used in this specification intends that existence of stated features, elements and / or components but does not exclude the presence or addition of one or more other features, elements, components, and / or groups thereof. In addition, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the term "exemplary" is intended to refer to an example or illustration.

[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 this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[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 the embodiments.

[0059] The optical lens according to the embodiments of the present application sequentially comprises, along the optical axis from the object side to the image side: a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a filter and a protective glass.

[0060] In some embodiments, the first lens can have a negative focal power, the object side surface of which is convex, and the image side surface of which is concave; the second lens can have a negative focal power, the object side surface of which is concave, and the image side surface of which is convex; the third lens can have a positive focal power; the fourth lens can have a positive focal power, the object side surface and the image side surface of which are both convex; the fifth lens can have a positive focal power, the object side surface and the image side surface of which are both convex; the sixth lens can have a negative focal power, the object side surface of which is concave; and the seventh lens can have a negative focal power, the object side surface of which is concave, and the image side surface of which is convex.

[0061] In some embodiments, the maximum field angle of the optical lens corresponds to a real image height IH and an entrance pupil diameter EPD, and the following relationship is satisfied: 3.0<IH / EPD<4.0. Satisfying the above range can increase the width of the light beam entering the optical lens, so that the brightness of the optical lens at the image plane is improved to avoid the generation of dark corners.

[0062] In some embodiments, the optical total track length TTL of the optical lens and the effective focal length f satisfy: 6.0 < TTL / f < 9.0. Satisfying the above requirement ensures sufficient space for adjusting the lens structure and optimizing the imaging effect.

[0063] In some embodiments, the optical total track length TTL of the optical lens and the real image height IH corresponding to the maximum field of view satisfy: 3.0 < TTL / IH < 5.0. Satisfying the above range can effectively balance the requirements of a large image surface and lens size of the optical lens.

[0064] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value FNO satisfy: 55° < FOV / FNO < 70°. Satisfying the above range is conducive to expanding the field of view of the optical lens and increasing the aperture of the optical lens, which is conducive to the optical lens to obtain more scene information to meet the requirements of large-range detection, and the implementation of the large-aperture feature is conducive to improving the problem of rapid decline of relative brightness in the edge field of view, thereby also conducive to obtaining more scene information.

[0065] In some embodiments, the maximum field of view FOV of the optical lens and the real image height IH corresponding to the maximum field of view and the light passing aperture D1 of the first lens object side satisfy: 0.7 < D1 / IH / tan(FOV / 2) < 0.98. Satisfying the above requirement can ensure the balance between the size of the optical lens and the large field of view and large image surface.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.5 < f1 / f < -1.5. Satisfying the above requirement can make the first lens have appropriate negative refractive power, which is conducive to reducing the inclination angle of the incident light, thereby reducing the correction difficulty of various aberrations of the optical lens.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -15.0 < f2 / f < -8.0. Satisfying the above requirement can make the second lens have appropriate negative refractive power, which can share the negative refractive power of the front end of the optical lens, thereby being conducive to avoiding excessive light deflection caused by the first lens refractive power being too concentrated, and reducing the difficulty of chromatic aberration correction of the optical lens.

[0068] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 5.0 < f3 / f < 7.0. Satisfying the above requirement can make the third lens have appropriate positive refractive power, converge light while reducing the light deflection angle, make the light trend smooth transition, balance various aberrations generated by the optical lens, and 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 f4 of the fourth lens satisfy: 1.5 < f4 / f < 2.5. Satisfying the above requirement, the fourth lens can have appropriate positive refractive power, reduce the light deflection angle while converging light rays, smoothly transition the light trend, balance various aberrations generated by the optical lens, and improve the imaging quality of the optical lens.

[0070] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.2 < f5 / f < 1.9. Satisfying the above requirement, the fifth lens can have appropriate positive refractive power, reduce the light deflection angle while converging light rays, smoothly transition the light trend, balance various aberrations generated by the optical lens, and improve the imaging quality of the optical lens.

[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.5 < f6 / f < -1.1. Satisfying the above requirement, the sixth lens can have appropriate negative refractive power, increase the imaging area of the optical lens, optimize the chromatic aberration of the optical lens, and improve the imaging quality of the optical lens.

[0072] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -11.0 < f7 / f < -9.0. Satisfying the above range, the seventh lens can have appropriate negative refractive power, and increase the imaging area of the optical lens.

[0073] In some embodiments, the effective focal length f of the optical lens, the maximum field of view FOV, and the real image height IH corresponding to the maximum field of view satisfy: 0.5 < (IH / 2) / (f*tan(FOV / 2)) < 0.6. Satisfying the above requirement, the optical distortion of the optical lens is well controlled, and the resolving power of the optical lens is improved.

[0074] In some embodiments, the Abbe number Vd of at least one of the fifth lens and the sixth lens satisfies: Vd > 80, and the Abbe number Vd5 of the fifth lens and the Abbe number Vd6 of the sixth lens satisfy: Vd5-Vd6 > 60. Satisfying the above range, the visible light and infrared light can be confocal.

[0075] In some embodiments, the fifth lens and the sixth lens can be bonded to form a bonded 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, improve the imaging quality of the optical lens, reduce the assembly sensitivity of the optical lens, and further reduce the processing difficulty of the optical lens and improve the assembly yield of the optical lens.

[0076] In some embodiments, the second lens, the fourth lens and the seventh lens can all adopt the surface type of aspheric lens to improve the resolution quality.

[0077] In order to make the system have better optical performance, a plurality of aspheric lenses are adopted in the lens, and the shape of each aspheric surface of the optical lens satisfies the following equation:

[0078]

[0079] 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, and A, B, C, D, E and F are respectively the second-order, fourth-order, sixth-order, eighth-order, tenth-order and twelfth-order surface coefficients.

[0080] 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 the 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.

[0081] Embodiment 1

[0082] Please refer to Figure 1 , which is the structure schematic diagram of the optical lens provided in the embodiment 1 of the application, and the optical lens comprises in sequence from the object side to the imaging surface along the optical axis: the first lens L1, the second lens L2, the third lens L3, the diaphragm ST, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the filter G1 and the protective glass G2.

[0083] The first lens L1 has negative focal power, the object side surface S1 is a convex surface, and the image side surface S2 is a concave surface;

[0084] The second lens L2 has negative focal power, the object side surface S3 is a concave surface, and the image side surface S4 is a convex surface;

[0085] The third lens L3 has positive focal power, and the object side surface S5 and the image side surface S6 are both convex surfaces;

[0086] The diaphragm ST;

[0087] The fourth lens L4 has positive focal power, and the object side surface S7 and the image side surface S8 are both convex surfaces;

[0088] The fifth lens L5 has positive focal power, and the object side surface S9 and the image side surface S10 are both convex surfaces;

[0089] ​The sixth lens L6 has negative refractive power, and both the object side S10 and the image side S11 are concave surfaces;

[0090] The fifth lens L5 and the sixth lens L6 form a cemented lens group, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens L6 is S10;

[0091] The seventh lens L7 has negative refractive power, and the object side S12 is a concave surface, and the image side S13 is a convex surface;

[0092] The object side S14 and the image side S15 of the filter G1 are both flat surfaces;

[0093] The object side S16 and the image side S17 of the protective glass G2 are both flat surfaces;

[0094] The imaging surface S18 is a flat surface.

[0095] The related parameters of each lens in the optical lens in Embodiment 1 are shown in Table 1-1.

[0096] Table 1-1

[0097]

[0098] The surface type parameters of the aspherical lens of the optical lens in Embodiment 1 are shown in Table 1-2.

[0099] Table 1-2

[0100]

[0101] In this embodiment, the field curvature 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

[0102] Figure 2 The field curvature curve of Embodiment 1 is shown, which represents the bending degree of light rays of different wavelengths on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image surface and the sagittal image surface is controlled within-0.02mm~0.03mm, which shows that the optical lens can well correct the field curvature.

[0103] Figure 3 ​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. 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.

[0104] Figure 4 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 surface, 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-10 μm~25 μm, which indicates that the optical lens can better correct the axial aberration.

[0105] Figure 5 The curve of the embodiment 1 is shown, which represents the axial 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. It can be seen from the figure that the shift amount of the axial aberration is controlled within-10 μm~25 μm, which indicates that the optical lens can better correct the axial aberration.

[0106] Embodiment 2

[0107] Please refer to Figure 6 , which is a structural schematic diagram of the optical lens provided in the embodiment 2 of the present application, which comprises, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, a diaphragm ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1 and a protective glass G2.

[0108] The first lens L1 has a negative focal power, the object side S1 is a convex surface, and the image side S2 is a concave surface;

[0109] The second lens L2 has a negative focal power, the object side S3 is a concave surface, and the image side S4 is a convex surface;

[0110] The third lens L3 has a positive focal power, the object side S5 and the image side S6 are both convex surfaces;

[0111] The diaphragm ST;

[0112] The fourth lens L4 has a positive focal power, the object side S7 and the image side S8 are both convex surfaces;

[0113] The fifth lens L5 has positive refractive power, and both the object side S9 and the image side S10 are convex surfaces;

[0114] The sixth lens L6 has negative refractive power, and both the object side S10 and the image side S11 are concave surfaces;

[0115] The fifth lens L5 and the sixth lens L6 form a cemented lens group, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens L6 is S10;

[0116] The seventh lens L7 has negative refractive power, and the object side S12 is a concave surface, and the image side S13 is a convex surface;

[0117] Both the object side S14 and the image side S15 of the filter G1 are flat surfaces;

[0118] Both the object side S16 and the image side S17 of the protective glass G2 are flat surfaces;

[0119] The imaging surface S18 is a flat surface.

[0120] The related parameters of each lens in the optical lens in Embodiment 2 are shown in Table 2-1.

[0121] Table 2-1

[0122]

[0123] The surface type parameters of the aspherical lens of the optical lens in Embodiment 2 are shown in Table 2-2.

[0124] Table 2-2

[0125]

[0126] In this embodiment, the field curvature curve, the MTF curve, the axial aberration curve, and the transverse chromatic aberration curve of the optical lens are shown in FIGS. Figure 7 、 Figure 8 、 Figure 9 、 Figure 10

[0127] Figure 7 The field curvature curve of Embodiment 2 is shown, which represents the bending degree of light rays of different wavelengths on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the 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-0.01mm~0.02mm, which shows that the optical lens can well correct the field curvature.

[0128] Figure 8 ​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 ability in the case of low frequency and high frequency.

[0129] Figure 9 The axial aberration curve of the embodiment 2 is shown, which represents the axial 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. It can be seen from the figure that the shift amount of the axial aberration is controlled within-10 μm~20 μm, which indicates that the optical lens can better correct the axial aberration.

[0130] Figure 10 The curve of the embodiment 2 is shown, which represents the axial 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. It can be seen from the figure that the shift amount of the axial aberration is controlled within-10 μm~20 μm, which indicates that the optical lens can better correct the axial aberration.

[0131] Embodiment 3

[0132] Please refer to Figure 11 , which is a structural schematic diagram of the optical lens provided in the embodiment 3 of the present application, which comprises, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, a stop ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1 and a protective glass G2.

[0133] The first lens L1 has a negative focal power, the object side S1 is a convex surface, and the image side S2 is a concave surface;

[0134] The second lens L2 has a negative focal power, the object side S3 is a concave surface, and the image side S4 is a convex surface;

[0135] The third lens L3 has a positive focal power, the object side S5 is a concave surface, and the image side S6 is a convex surface;

[0136] The stop ST;

[0137] The fourth lens L4 has a positive focal power, and the object side S7 and the image side S8 are both convex surfaces;

[0138] The fifth lens L5 has positive refractive power, and both the object side S9 and the image side S10 are convex surfaces;

[0139] The sixth lens L6 has negative refractive power, and both the object side S10 and the image side S11 are concave surfaces;

[0140] The fifth lens L5 and the sixth lens L6 form a cemented lens group, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens L6 is S10;

[0141] The seventh lens L7 has negative refractive power, and the object side S12 is a concave surface, and the image side S13 is a convex surface;

[0142] Both the object side S14 and the image side S15 of the filter G1 are flat surfaces;

[0143] Both the object side S16 and the image side S17 of the protective glass G2 are flat surfaces;

[0144] The imaging surface S18 is a flat surface.

[0145] The related parameters of each lens in the optical lens in Embodiment 3 are shown in Table 3-1.

[0146] Table 3-1

[0147]

[0148] The surface type parameters of the aspherical lens of the optical lens in Embodiment 3 are shown in Table 3-2.

[0149] Table 3-2

[0150]

[0151] In this embodiment, the field curvature curve, the MTF curve, the axial aberration curve, and the transverse chromatic aberration curve of the optical lens are shown in FIGS. Figure 12 、 Figure 13 、 Figure 14 、 Figure 15

[0152] Figure 12 The field curvature curve of Embodiment 3 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: °). It can be seen from the figure that the field curvature of the meridional image surface and the sagittal image surface is controlled within-0.01 mm~0.025 mm, which shows that the optical lens can well correct the field curvature.

[0153] Figure 13 ​The MTF (Modulation Transfer Function) curve of the embodiment 3 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 ability in the case of low frequency and high frequency.

[0154] Figure 14 The axial aberration curve of the embodiment 3 is shown, which represents the axial 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. It can be seen from the figure that the shift amount of the axial aberration is controlled within-10 μm~15 μm, which indicates that the optical lens can better correct the axial aberration.

[0155] Figure 15 The curve of the embodiment 3 is shown, which represents the axial 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. It can be seen from the figure that the shift amount of the axial aberration is controlled within-10 μm~15 μm, which indicates that the optical lens can better correct the axial aberration.

[0156] Embodiment 4

[0157] Please refer to Figure 16 , which is a structural schematic diagram of the optical lens provided in the embodiment 4 of the present application, which comprises, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, a stop ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1 and a protective glass G2.

[0158] The first lens L1 has a negative focal power, the object side S1 is a convex surface, and the image side S2 is a concave surface;

[0159] The second lens L2 has a negative focal power, the object side S3 is a concave surface, and the image side S4 is a convex surface;

[0160] The third lens L3 has a positive focal power, the object side S5 is a convex surface, and the image side S6 is a concave surface;

[0161] The stop ST;

[0162] The fourth lens L4 has a positive focal power, and the object side S7 and the image side S8 are both convex surfaces;

[0163] The fifth lens L5 has positive refractive power, and both the object side S9 and the image side S10 are convex surfaces;

[0164] The sixth lens L6 has negative refractive power, and both the object side S10 and the image side S11 are concave surfaces;

[0165] The fifth lens L5 and the sixth lens L6 form a cemented lens group, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens L6 is S10;

[0166] The seventh lens L7 has negative refractive power, and the object side S12 is a concave surface, and the image side S13 is a convex surface;

[0167] Both the object side S14 and the image side S15 of the filter G1 are flat surfaces;

[0168] Both the object side S16 and the image side S17 of the protective glass G2 are flat surfaces;

[0169] The imaging surface S18 is a flat surface.

[0170] The related parameters of the lenses in the optical lens in Embodiment 4 are shown in Table 4-1.

[0171] Table 4-1

[0172]

[0173] The surface type parameters of the aspherical lenses of the optical lens in Embodiment 4 are shown in Table 4-2.

[0174] Table 4-2

[0175]

[0176] In this embodiment, the field curvature curve, the MTF curve, the axial aberration curve, and the transverse chromatic aberration curve of the optical lens are shown in FIGS. Figure 17 、 Figure 18 、 Figure 19 、 Figure 20

[0177] Figure 17 The field curvature curve of Embodiment 4 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: °). It can be seen from the figure that the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.02 mm, which shows that the optical lens can well correct the field curvature.

[0178] Figure 18 ​The MTF (Modulation Transfer Function) curve of the 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. 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 ability in the case of low frequency and high frequency.

[0179] Figure 19 The axial aberration curve of the embodiment 4 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-5 μm~20 μm, which indicates that the optical lens can better correct the axial aberration.

[0180] Figure 20 The curve of the embodiment 4 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-4 μm~9 μm, which indicates 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.

[0181] Embodiment 5

[0182] Please refer to Figure 21 , which is a structural schematic diagram of the optical lens provided in the embodiment 5 of the present application, which comprises, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, a stop ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1 and a protective glass G2.

[0183] The first lens L1 has a negative focal power, the object side S1 is a convex surface, and the image side S2 is a concave surface;

[0184] The second lens L2 has a negative focal power, the object side S3 is a concave surface, and the image side S4 is a convex surface;

[0185] The third lens L3 has a positive focal power, the object side S5 is a convex surface, and the image side S6 is a concave surface;

[0186] The stop ST;

[0187] The fourth lens L4 has a positive focal power, and the object side S7 and the image side S8 are both convex surfaces;

[0188] The fifth lens L5 has positive refractive power, and both the object side S9 and the image side S10 are convex surfaces;

[0189] The sixth lens L6 has negative refractive power, and the object side S10 is a concave surface, and the image side S11 is a convex surface;

[0190] The fifth lens L5 and the sixth lens L6 form a cemented lens group, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens L6 is S10;

[0191] The seventh lens L7 has negative refractive power, and the object side S12 is a concave surface, and the image side S13 is a convex surface;

[0192] The object side S14 and the image side S15 of the filter G1 are both flat surfaces;

[0193] The object side S16 and the image side S17 of the protective glass G2 are both flat surfaces;

[0194] The imaging surface S18 is a flat surface.

[0195] The related parameters of each lens in the optical lens in Embodiment 5 are shown in Table 5-1.

[0196] Table 5-1

[0197]

[0198] The surface type parameters of the aspherical lens of the optical lens in Embodiment 5 are shown in Table 5-2.

[0199] Table 5-2

[0200]

[0201] In this embodiment, the field curvature curve, the MTF curve, the axial aberration curve, and the transverse chromatic aberration curve of the optical lens are shown in Figure 22 、 Figure 23 、 Figure 24 、 Figure 25

[0202] Figure 22 The field curvature curve of Embodiment 5 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: °). It can be seen from the figure that the field curvature of the meridional image surface and the sagittal image surface is controlled within-0.01mm~0.02mm, which shows that the optical lens can well correct the field curvature.

[0203] Figure 23 ​The MTF (Modulation Transfer Function) curve of the optical lens of Example 5 is shown, which represents the modulation degree of lens imaging 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 present embodiment is above 0.5 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 low and high frequency cases.

[0204] Figure 24 The axial aberration curve of Example 5 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. As can be seen from the figure, the shift of the axial aberration is controlled within-10 μm~20 μm, which shows that the optical lens can better correct the axial aberration.

[0205] Figure 25 The curve of the axial chromatic aberration of Example 5 is shown, which represents the chromatic aberration of different image heights on the imaging surface at each wavelength relative to the center wavelength (0.55 μm), the horizontal axis represents the axial chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the figure, the axial chromatic aberration of the longest wavelength and the shortest wavelength is controlled within-0.05 μm~5.5 μm, which shows that the optical lens can very well correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image surface.

[0206] Please refer to Table 6, which is the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, the total optical length TTL, the aperture value FNO, the real image height IH, and the maximum field of view angle FOV of the optical lens, and the numerical value corresponding to each conditional expression in each embodiment.

[0207] Table 6

[0208]

[0209] In summary of the above embodiments, the optical lens provided by the present application has infrared confocal function, meets the clarity requirements of daytime and night imaging, improves the resolving power of the optical lens, reduces the aberration, and improves the imaging quality of the optical lens through reasonable configuration of each lens surface and reasonable matching of optical power.

[0210] 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 expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0211] The above-described embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but cannot be understood as a limitation on the patent scope of the present application. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An optical lens, in total seven pieces of lenses, characterized in that, In order from the object side to the imaging plane along the optical axis, there are in sequence: a first lens with negative refractive power, whose object side surface is a convex surface and whose image side surface is a concave surface; a second lens with negative refractive power, whose object side surface is a concave surface and whose image side surface is a convex surface; a third lens with positive refractive power; a diaphragm; a fourth lens with positive refractive power, whose object side surface and image side surface are both convex surfaces; a fifth lens with positive refractive power, whose object side surface and image side surface are both convex surfaces; a sixth lens with negative refractive power, whose object side surface is a concave surface; a seventh lens with negative refractive power, whose object side surface is a concave surface and whose image side surface is a convex surface; a real image height IH corresponding to a maximum field angle of the optical lens and an entrance pupil diameter EPD satisfy: 3.0<IH / EPD<4.0; an effective focal length f of the optical lens and a focal length f7 of the seventh lens satisfy: -11.0<f7 / f<-9.

0.

2. The optical lens of claim 1, wherein, an optical total length TTL of the optical lens and the effective focal length f satisfy: 6.0<TTL / f<9.

0.

3. The optical lens of claim 1, wherein, an optical total length TTL of the optical lens and a real image height IH corresponding to a maximum field angle satisfy: 3.0<TTL / IH<5.

0.

4. The optical lens of claim 1, wherein, a maximum field angle FOV of the optical lens and an aperture value FNO satisfy: 55°<FOV / FNO<70°.

5. The optical lens of claim 1, wherein, the maximum field angle FOV of the optical lens, a real image height IH corresponding to the maximum field angle, and an entrance pupil diameter D1 of the object side surface of the first lens satisfy: 0.7<D1 / IH / tan(FOV / 2)<0.

98.

6. The optical lens of claim 1, wherein, the effective focal length f of the optical lens and a focal length f1 of the first lens satisfy: -2.5<f1 / f<-1.

5.

7. The optical lens of claim 1, wherein, the effective focal length f of the optical lens and a focal length f3 of the third lens satisfy: 5.0<f3 / f<8.

0.

8. The optical lens of claim 1, wherein, the effective focal length f of the optical lens and a focal length f4 of the fourth lens satisfy: 1.5<f4 / f<2.

5.

9. The optical lens of claim 1, wherein, the effective focal length f of the optical lens and a focal length f6 of the sixth lens satisfy: -1.5<f6 / f<-1.

1.

10. The optical lens of claim 1, wherein, the effective focal length f of the optical lens and a focal length f2 of the second lens satisfy: -15.0<f2 / f<-8.0.

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