Optical lens

Abstract

The application provides an optical lens, which comprises six lenses arranged along an optical axis from an object side to an imaging surface in sequence, wherein the six lenses are: a first lens with negative focal power, the object side of the first lens is a convex surface, and the image side of the first lens is a concave surface; a second lens with negative focal power, the object side of the second lens is a concave surface, and the image side of the second lens is a convex surface; a third lens with positive focal power, the object side and the image side of the third lens are both convex surfaces; a fourth lens with negative focal power, the object side of the fourth lens is a convex surface, and the image side of the fourth lens is a concave surface; a fifth lens with positive focal power, the object side and the image side of the fifth lens are both convex surfaces; and a sixth lens with negative focal power, the object side of the sixth lens is a convex surface, and the image side of the sixth lens is a concave surface; and the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.4 < f1 / f < 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 the focal 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 increasing demand for driving experience, vehicle application optical lenses are increasingly used in intelligent driving, and vehicle optical lenses are playing an increasingly important role in the automotive industry.

[0003] The camera of the vehicle DMS system belongs to the imaging camera and is mainly used in the cabin. Its main functions include driver fatigue detection, face recognition and other functions. The existing DMS system lens requires not only optical lenses with light and thin, small front aperture shape and high pixel, high resolution and other characteristics, but also clear imaging 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 six lenses in total, and the lenses are arranged in order along the optical axis from the object side to the imaging surface as follows:

[0006] The first lens with negative focal power has a convex object side surface and a concave image side surface;

[0007] The second lens with negative focal power has a concave object side surface and a convex image side surface;

[0008] The third lens with positive focal power has a convex object side surface and a convex image side surface;

[0009] The fourth lens with negative focal power has a convex object side surface and a concave image side surface;

[0010] The fifth lens with positive focal power has a convex object side surface and a convex image side surface;

[0011] The sixth lens with negative focal power has a convex object side surface and a concave image side surface;

[0012] The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.4 < f1 / f < 0.

[0013] Further preferably, the object side surface curvature radius R3 and the image side surface curvature radius R4 of the second lens satisfy: -20 < (R3+R4) / (R3-R4) < -10.

[0014] Further preferably, a central thickness CT2 of the second lens along the optical axis and an air gap CT of the first lens to the second lens on the optical axis satisfy: 0.15 < CT2 / CT < 0.3. 12 Further preferably, a central thickness CT2 of the second lens along the optical axis and an air gap CT of the first lens to the second lens on the optical axis satisfy: 0.15 < CT2 / CT < 0.3. 12 <0.3.

[0015] Further preferably, an overall length TTL of the optical lens and an effective focal length f satisfy: 4.5 < TTL / f < 5.5.

[0016] Further preferably, an effective focal length f of the optical lens, a maximum field angle FOV and a real image height IH corresponding to the maximum field angle satisfy: 0.3 < (IH / 2) / (f x tan(FOV / 2)) < 0.7.

[0017] Further preferably, an effective focal length f of the optical lens and a real image height IH corresponding to the maximum field angle satisfy: 1.5 < IH / f < 2.5.

[0018] Further preferably, an effective focal length f of the optical lens and a focal length f2 of the second lens satisfy: -34.5 < f2 / f < -15.0.

[0019] Further preferably, an effective focal length f of the optical lens and a focal length f3 of the third lens satisfy: 1.5 < f3 / f < 1.7.

[0020] Further preferably, an effective focal length f of the optical lens and a focal length f4 of the fourth lens satisfy: -1.5 < f4 / f < -1.0.

[0021] Further preferably, an effective focal length f of the optical lens and a focal length f5 of the fifth lens satisfy: 0.7 < f5 / f < 0.9.

[0022] The optical lens provided by the present application can effectively limit the length of the lens, is conducive to the miniaturization of the optical lens, and improves the resolving power of the optical lens, reduces aberration, and improves the imaging quality of the optical lens by reasonable configuration of the surface shape of each lens and reasonable matching of the focal power. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the accompanying drawings, wherein:

[0024] Figure 1 FIG. 1 is a structure diagram of an optical lens according to an embodiment of the present application.

[0025] Figure 2 FIG. 2 is a field curvature curve of the optical lens according to the embodiment of the present application.

[0026] Figure 3F-Tanθ distortion curve diagram of the optical lens in embodiment 1 of the present application.

[0027] Figure 4 MTF curve diagram of the optical lens in embodiment 1 of the present application.

[0028] Figure 5 Relative luminance curve diagram of the optical lens in embodiment 1 of the present application.

[0029] Figure 6 Axial aberration curve diagram of the optical lens in embodiment 1 of the present application.

[0030] Figure 7 Vignetting curve diagram of the optical lens in embodiment 1 of the present application.

[0031] Figure 8 Structure schematic diagram of the optical lens in embodiment 2 of the present application.

[0032] Figure 9 Curvature of field curve diagram of the optical lens in embodiment 2 of the present application.

[0033] Figure 10 F-Tanθ distortion curve diagram of the optical lens in embodiment 2 of the present application.

[0034] Figure 11 MTF curve diagram of the optical lens in embodiment 2 of the present application.

[0035] Figure 12 Relative luminance curve diagram of the optical lens in embodiment 2 of the present application.

[0036] Figure 13 Axial aberration curve diagram of the optical lens in embodiment 2 of the present application.

[0037] Figure 14 Vignetting curve diagram of the optical lens in embodiment 2 of the present application.

[0038] Figure 15 Structure schematic diagram of the optical lens in embodiment 3 of the present application.

[0039] Figure 16 Curvature of field curve diagram of the optical lens in embodiment 3 of the present application.

[0040] Figure 17 F-Tanθ distortion curve diagram of the optical lens in embodiment 3 of the present application.

[0041] Figure 18 MTF curve diagram of the optical lens in embodiment 3 of the present application.

[0042] Figure 19 Relative luminance curve diagram of the optical lens in embodiment 3 of the present application.

[0043] Figure 20 Axial aberration curve of the optical lens in embodiment 3 of the present application.

[0044] Figure 21 Vignetting curve of the optical lens in embodiment 3 of the present application.

[0045] Figure 22 Structural schematic diagram of the optical lens in embodiment 4 of the present application.

[0046] Figure 23 Curvature of field curve of the optical lens in embodiment 4 of the present application.

[0047] Figure 24 F-Tanθ distortion curve of the optical lens in embodiment 4 of the present application.

[0048] Figure 25 MTF curve of the optical lens in embodiment 4 of the present application.

[0049] Figure 26 Relative illumination curve of the optical lens in embodiment 4 of the present application.

[0050] Figure 27 Axial aberration curve of the optical lens in embodiment 4 of the present application.

[0051] Figure 28 Vignetting curve of the optical lens in embodiment 4 of the present application.

[0052] Figure 29 Structural schematic diagram of the optical lens in embodiment 5 of the present application.

[0053] Figure 30 Curvature of field curve of the optical lens in embodiment 5 of the present application.

[0054] Figure 31 F-Tanθ distortion curve of the optical lens in embodiment 5 of the present application.

[0055] Figure 32 MTF curve of the optical lens in embodiment 5 of the present application.

[0056] Figure 33 Relative illumination curve of the optical lens in embodiment 5 of the present application.

[0057] Figure 34 Axial aberration curve of the optical lens in embodiment 5 of the present application.

[0058] Figure 35 Vignetting curve of the optical lens in embodiment 5 of the present application.

[0059] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0060] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0061] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0062] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0063] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0064] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, 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 in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0065] 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 overly idealized or overly formal sense unless expressly so defined herein.

[0066] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0067] 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, and a filter.

[0068] In some embodiments, the first lens can have a negative focal power, which is conducive to reducing the incident angle of the light rays, thereby effectively sharing the large field of view on the object side. The object side of the first lens is convex, and the image side is concave, which is conducive to collecting as much edge field of view light as possible into the rear optical lens, thereby realizing large-angle light collection.

[0069] In some embodiments, the second lens can have a negative focal power, and the object side of the second lens is concave, and the image side is convex, which can share the negative focal power of the front end of the lens, thereby reducing the excessive folding of the light rays caused by the focal power of the first lens, and reducing the difficulty of chromatic aberration correction of the optical lens.

[0070] In some embodiments, the third lens can have a positive focal power, which is conducive to converging the light rays while reducing the light ray folding angle, so that the light rays transition smoothly. The object side and the image side of the third lens are both convex, which can reduce the influence of the spherical aberration and the astigmatism generated by the third lens itself on the optical lens, thereby improving the imaging quality of the optical lens.

[0071] In some embodiments, the fourth lens can have a negative focal power, and the object side of the fourth lens is convex, and the image side is concave, which is conducive to balancing various types of aberrations generated by the optical lens, thereby improving the imaging quality of the optical lens.

[0072] In some embodiments, the fifth lens can have a positive focal power, which is conducive to improving the light converging ability of the optical lens. The object side and the image side of the fifth lens are both convex, which can reduce the spherical aberration and the coma generated by the fifth lens itself, thereby improving the imaging quality of the optical lens.

[0073] In some embodiments, the sixth lens can have a negative refractive power, which is beneficial to increase the imaging area of the optical lens and improve the imaging quality of the optical lens. The object side surface of the sixth lens is convex, and the image side surface is concave, which can optimize the chromatic aberration of the optical lens and improve the imaging quality of the optical lens.

[0074] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.4 < f1 / f < 0. Satisfying the above range is beneficial to smooth transition of light rays and to make as many large-angle light rays as possible enter the rear lens, thereby improving the illumination of the lens.

[0075] In some embodiments, the object side surface radius of curvature R3 and the image side surface radius of curvature R4 of the second lens satisfy: -20 < (R3+R4) / (R3-R4) < -10. Satisfying the above range is beneficial to strengthen the correction of high-order aberrations and reduce the attenuation degree of the relative illumination of the optical lens by adjusting the object side surface and the image side surface radius of curvature of the second lens.

[0076] In some embodiments, the central thickness CT2 of the second lens along the optical axis and the air gap CT 12 satisfy: 0.15 < CT2 / CT 12 <0.3. Satisfying the above range is beneficial to lens assembly, and moderately adjusting the thickness of the second lens is helpful for lens manufacturing and molding, thereby improving product yield.

[0077] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f satisfy: 4.5 < TTL / f < 5.5. Satisfying the above range can effectively limit the length of the lens and realize miniaturization of the optical lens.

[0078] In some embodiments, the effective focal length f of the optical lens and the maximum field of view FOV and the real image height IH corresponding to the maximum field of view satisfy: 0.3 < (IH / 2) / (f x tan(FOV / 2)) < 0.7. Satisfying the above range is beneficial to balance the size of the field of view and the size of the F-Tanθ distortion of the optical lens, thereby improving the imaging quality of the optical lens.

[0079] In some embodiments, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field of view satisfy: 1.5 < IH / f < 2.5. Satisfying the above range is beneficial to balance the size of the field of view and the size of the F-Tanθ distortion of the optical lens, thereby improving the imaging quality of the optical lens.

[0080] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -34.5 < f2 / f < -15.0. Satisfying the above range, the second lens can have appropriate negative refractive power, can share the negative refractive power of the front end of the lens, thereby reducing the excessive deflection of light caused by the excessive concentration of the refractive power of the first lens, and reducing the difficulty of chromatic aberration correction of the optical lens.

[0081] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.5 < f3 / f < 1.7. Satisfying the above range, the third lens can have appropriate positive refractive power, can reduce the influence of the spherical aberration and astigmatism generated by the third lens itself on the optical lens, and improve the imaging quality of the optical lens.

[0082] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -1.5 < f4 / f < -1.0. Satisfying the above range, the fourth lens can have appropriate negative refractive power, which is beneficial to balance various aberrations generated by the optical lens, and improve the imaging quality of the optical lens.

[0083] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.7 < f5 / f < 0.9. Satisfying the above range, the fifth lens can have appropriate positive refractive power, which can reduce the spherical aberration and coma generated by the fifth lens itself, and improve the imaging quality of the optical lens.

[0084] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -6.5 < f6 / f < -4.5. Satisfying the above range, the sixth lens can have appropriate negative refractive power, which is beneficial to increase the imaging area of the optical lens, and can optimize the chromatic aberration of the optical lens, and improve the imaging quality of the optical lens.

[0085] In some embodiments, the maximum field of view FOV of the optical lens satisfies: 115° < FOV < 145°. Satisfying the above range, the optical lens can have a large field of view.

[0086] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value FNO satisfy: 55° < FOV / FNO < 75°. Satisfying the above range, the field of view of the optical lens can be expanded and the aperture of the optical lens can be increased, which is beneficial to the optical lens to obtain more scene information, meet the demand of large range detection, and the realization of large aperture characteristics is beneficial to improve the problem that the relative brightness of the edge field of view decreases rapidly, thereby also beneficial to obtain more scene information.

[0087] In some embodiments, the optical total length TTL of the optical lens and the real image height IH corresponding to the maximum field of view angle satisfy: 2.0 < TTL / IH < 2.8. Satisfying the above range can effectively balance the image height of the optical lens and the miniaturization requirement.

[0088] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD satisfy: 3.5 < IH / EPD < 5.0. 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 dark corners.

[0089] In some embodiments, the maximum field of view angle FOV of the optical lens and the real image height IH corresponding to the maximum field of view angle and the clear aperture D1 of the first lens object side satisfy: 0.3 < D1 / IH / tan(FOV / 2) < 0.7. Satisfying the above range can ensure the balance between the size of the optical lens and the field of view angle and the image plane.

[0090] In some embodiments, the fourth lens and the fifth lens can be glued to form a glued lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens. In addition, the glued lens can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0091] In order to make the system have better optical performance, a plurality of aspheric lenses are used in the lens, and each aspheric surface shape of the optical lens satisfies the following equation:

[0092]

[0093] Wherein, z is the distance of the curved surface and the vertex of the curved surface in the direction of the optical axis, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the quadratic surface coefficient, A, B, C, D, E and F are the second-order, fourth-order, sixth-order, eighth-order, tenth-order and twelfth-order curved surface coefficients, respectively.

[0094] The application will be further described in the following embodiments. In each embodiment, the thickness, the radius of curvature and the material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments, and any changes, substitutions, combinations or simplifications made without departing from the innovative points of the application should be regarded as equivalent replacement methods, and are included in the protection scope of the application.

[0095] Embodiment 1

[0096] Please refer to Figure 1Figure 1 shows a structural schematic diagram of an optical lens provided in Embodiment 1 of the present application, which comprises, along an optical axis from an object side to an 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 and a filter G1.

[0097] The first lens L1 has a negative focal power, and its object side S1 is a convex surface and its image side S2 is a concave surface.

[0098] The second lens L2 has a negative focal power, and its object side S3 is a concave surface and its image side S4 is a convex surface.

[0099] The third lens L3 has a positive focal power, and its object side S5 and its image side S6 are both convex surfaces.

[0100] The stop ST.

[0101] The fourth lens L4 has a negative focal power, and its object side S7 is a convex surface and its image side S8 is a concave surface.

[0102] The fifth lens L5 has a positive focal power, and its object side S8 and its image side S9 are both convex surfaces.

[0103] The fourth lens L4 and the fifth lens L5 form a cemented lens group, and the cemented surface S8 is between the image side of the fourth lens L4 and the object side of the fifth lens L5.

[0104] The sixth lens L6 has a negative focal power, and its object side S10 is a convex surface and its image side S11 is a concave surface.

[0105] The object side S12 and the image side S13 of the filter G1 are both flat surfaces.

[0106] The imaging surface S14 is a flat surface.

[0107] The related parameters of the lenses in the optical lens in Embodiment 1 are shown in Table 1-1.

[0108] Table 1-1

[0109]

[0110] The surface type parameters of the aspheric lenses in the optical lens in Embodiment 1 are shown in Table 1-2.

[0111] Table 1-2

[0112] Surface number K A B C D E F S1 3.17E+00 0.00E+00 8.19E-03 -1.20E-03 2.35E-05 -3.31E-06 3.49E-07 S2 2.06E-01 0.00E+00 1.24E-02 1.45E-03 -1.05E-03 4.46E-04 -1.67E-04 S3 -2.86E+00 0.00E+00 -3.56E-03 7.86E-03 -7.85E-04 -2.07E-04 4.13E-05 S4 2.54E+00 0.00E+00 1.44E-02 4.00E-03 2.28E-03 -1.25E-03 2.26E-04 S7 1.73E+01 0.00E+00 -2.58E-02 3.23E-02 -3.56E-02 1.75E-02 -3.55E-03 S8 -1.85E+00 0.00E+00 2.26E-02 2.12E-03 -3.28E-03 7.78E-04 -5.54E-05 S9 -5.85E+00 0.00E+00 -1.05E-02 3.08E-03 -7.56E-04 2.24E-04 -2.12E-05 S10 -3.85E+00 0.00E+00 -3.09E-02 -2.66E-04 4.22E-05 1.49E-04 -1.89E-05 S11 -8.69E-01 0.00E+00 -6.24E-02 7.21E-03 -8.44E-04 8.63E-05 -5.31E-06

[0113] In this embodiment, the field curvature curve, the F-Tanθ distortion curve, the MTF curve, the relative illumination curve, the axial aberration curve and the transverse chromatic aberration curve of the optical lens are respectively shown in Figure 2 、 Figure 3、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 as shown.

[0114] Figure 2 The field curvature curve of Example 1 is shown, which represents the curvature of light rays of different wavelengths on the meridional image surface and sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.12mm-0mm, which shows that the optical lens can well correct the field curvature.

[0115] Figure 3 The F-Tanθ distortion curve of Example 1 is shown, which represents the F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging surface, the horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -40%-0, the image compression in the edge angle region is relatively flat, and the clarity of the expanded image is effectively improved.

[0116] Figure 4 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies under each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of the present embodiment is above 0.3 within the full field of view, and within the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in low and high frequency conditions.

[0117] Figure 5 The relative illumination curve of Example 1 is shown, which represents the relative illumination value of different field angles on the imaging surface, the horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 70% at the maximum half field angle, which shows that the optical lens has good relative illumination.

[0118] Figure 6 The axial aberration curve of Example 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging surface, the horizontal axis represents the axial aberration value (unit: μm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the offset of the axial aberration is controlled within -50μm-35μm, which shows that the optical lens can well correct the axial aberration.

[0119] Figure 7The vertical axis represents the relative value of the vertical color aberration of each wavelength to the central wavelength (0.55 μm) (unit: μm), and the longitudinal axis represents the normalized field of view. It can be seen from the figure that the vertical color aberration of the longest wavelength and the shortest wavelength is controlled within -2 μm-8 μm, which indicates that the optical lens can well correct the color aberration of the edge field of view and the secondary spectrum of the whole image surface.

[0120] Embodiment 2

[0121] Referring to Figure 8 , a structure schematic diagram of the optical lens provided in Embodiment 2 of the present application is shown, and the main difference between the present embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0122] The related parameters of each lens in the optical lens in Embodiment 2 are shown in Table 2-1.

[0123] Table 2-1

[0124]

[0125] The surface type parameters of the aspherical lens of the optical lens in Embodiment 2 are shown in Table 2-2.

[0126] Table 2-2

[0127] Surface number K A B C D E F S1 -2.87E+00 0.00E+00 6.46E-03 -1.13E-03 4.17E-05 -5.52E-06 4.24E-07 S2 1.96E-01 0.00E+00 1.11E-02 3.81E-04 -1.02E-03 4.33E-04 -1.61E-04 S3 -4.25E+00 0.00E+00 -1.20E-02 6.23E-03 -5.38E-04 -3.65E-04 8.16E-05 S4 2.27E+00 0.00E+00 9.13E-03 3.23E-03 1.14E-03 -7.94E-04 1.62E-04 S7 1.63E+01 0.00E+00 -2.59E-02 3.00E-02 -3.25E-02 1.56E-02 -3.07E-03 S8 -2.13E+00 0.00E+00 1.48E-02 8.22E-04 -1.74E-03 3.97E-04 -1.70E-05 S9 -2.32E+00 0.00E+00 -1.06E-02 3.89E-03 -1.20E-03 2.19E-04 -1.73E-05 S10 -4.69E+00 0.00E+00 -4.31E-02 1.54E-03 -1.95E-04 8.19E-05 -7.60E-06 S11 -1.08E+00 0.00E+00 -6.03E-02 6.93E-03 -6.31E-04 3.64E-05 -7.94E-07

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

[0129] Figure 9 The field curvature curve of Embodiment 2 is shown, which indicates the bending degree of light rays of different wavelengths on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the longitudinal axis represents the half field of view (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 -0.12 mm-0 mm, which indicates that the optical lens can well correct the field curvature.

[0130] Figure 10The F-Tanθ distortion curve of the embodiment 2 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 (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 -50%~0, the image compression in the edge angle region is relatively gentle, and the clarity of the expanded image is effectively improved.

[0131] Figure 11 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. As can be seen from the figure, the MTF value of the embodiment is above 0.3 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.

[0132] Figure 12 The relative illumination curve of the embodiment 2 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, which indicates that the optical lens has good relative illumination.

[0133] Figure 13 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 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 -50 μm~40 μm, which indicates that the optical lens can better correct the axial aberration.

[0134] Figure 14 The sagittal chromatic aberration curve of the embodiment 2 is shown, which represents the chromatic aberration of each wavelength at different image heights on the imaging plane relative to the center wavelength (0.55 μm), the horizontal axis represents the sagittal chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field angle. As can be seen from the figure, the sagittal chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -2 μm~10 μm, which indicates that the optical lens can very well correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0135] Embodiment 3

[0136] Please refer to Figure 15 , which is a structural schematic diagram of the optical lens provided in the embodiment 3 of the present application. Compared with the embodiment 1, the main difference of the embodiment is that the curvature radius and the lens thickness of each lens surface are different.

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

[0138] Table 3-1

[0139]

[0140]

[0141] The surface type parameters of the aspherical lens of the optical lens in embodiment 3 are shown in Table 3-2.

[0142] Table 3-2

[0143] Surface number K A B C D E F S1 -1.17E+01 0.00E+00 -7.44E-04 -5.19E-04 1.01E-04 -1.00E-05 3.67E-07 S2 -2.44E-01 0.00E+00 -1.50E-02 1.96E-03 -1.30E-03 4.32E-04 -6.89E-05 S3 -4.76E+00 0.00E+00 -1.61E-02 3.82E-03 4.43E-05 -2.10E-04 2.70E-05 S4 9.37E-01 0.00E+00 6.85E-03 9.42E-04 5.10E-04 -2.09E-04 2.82E-05 S7 1.51E+01 0.00E+00 -1.78E-02 1.50E-02 -1.59E-02 7.16E-03 -1.36E-03 S8 -3.43E+00 0.00E+00 6.36E-02 -2.59E-02 7.51E-03 -1.27E-03 9.33E-05 S9 -5.30E+00 0.00E+00 -1.58E-02 5.09E-03 -1.24E-03 1.59E-04 -8.75E-06 S10 -5.55E+00 0.00E+00 -4.50E-02 3.63E-03 2.74E-04 -1.69E-04 1.37E-05 S11 -1.74E+00 0.00E+00 -5.57E-02 9.46E-03 -1.22E-03 8.25E-05 -2.17E-06

[0144] In this embodiment, the field curvature curve, F-Tanθ distortion curve, MTF curve, relative illumination curve, axial aberration curve and transverse chromatic aberration curve of the optical lens are shown in FIGS. 3-1 to 3-6 respectively. Figure 16 、 Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 、 Figure 21

[0145] Figure 16 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 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 -0.15mm~0.05mm, which shows that the optical lens can well correct the field curvature.

[0146] 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 (unit: %), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the F-Tanθ distortion of the optical lens is controlled within -65%~0, the image compression in the edge angle region is relatively flat, and the clarity of the expanded image is effectively improved.

[0147] Figure 18 ​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 0.3 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.

[0148] Figure 19 The relative illumination curve of the embodiment 3 is shown, which represents the relative illumination value of different field angles on the imaging surface, the horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). It can be seen from the figure that the relative illumination value of the optical lens is still greater than 70% at the maximum half field angle, which indicates that the optical lens has good relative illumination.

[0149] Figure 20 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 offset of the axial aberration is controlled within-40 μm-50 μm, which indicates that the optical lens can better correct the axial aberration.

[0150] Figure 21 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 offset of the axial aberration is controlled within-40 μm-50 μm, which indicates that the optical lens can better correct the axial aberration.

[0151] Embodiment 4

[0152] Please refer to Figure 22 , which is a structural schematic diagram of the optical lens provided in the embodiment 4 of the present application. Compared with the embodiment 1, the main difference of the embodiment is that the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0153] The related parameters of each lens in the optical lens in the embodiment 4 are shown in Table 4-1.

[0154] Table 4-1

[0155]

[0156]

[0157] The surface shape parameters of the aspherical lens of the optical lens in Example 4 are shown in Table 4-2.

[0158] Table 4-2

[0159] Surface number K A B C D E F S1 -1.31E+01 0.00E+00 -5.86E-04 -5.31E-04 1.03E-04 -1.01E-05 3.61E-07 S2 -2.49E-01 0.00E+00 -1.51E-02 2.01E-03 -1.31E-03 4.31E-04 -6.60E-05 S3 -4.81E+00 0.00E+00 -1.47E-02 3.88E-03 5.29E-05 -1.94E-04 2.30E-05 S4 9.67E-01 0.00E+00 7.43E-03 1.05E-03 5.08E-04 -2.15E-04 2.79E-05 S7 1.48E+01 0.00E+00 -1.79E-02 1.37E-02 -1.40E-02 6.01E-03 -1.11E-03 S8 -3.46E+00 0.00E+00 6.43E-02 -2.59E-02 7.45E-03 -1.28E-03 9.67E-05 S9 -4.76E+00 0.00E+00 -1.66E-02 4.83E-03 -1.21E-03 1.62E-04 -9.15E-06 S10 -4.69E+00 0.00E+00 -4.64E-02 3.29E-03 2.83E-04 -1.62E-04 1.25E-05 S11 -1.53E+00 0.00E+00 -5.75E-02 9.41E-03 -1.22E-03 7.96E-05 -2.04E-06

[0160] In this embodiment, the field curvature curve, F-Tanθ distortion curve, MTF curve, relative illumination curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are shown in FIGS. 4-2 to 4-7, respectively. Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28

[0161] Figure 23 FIG. 4-2 shows the field curvature curve of Example 4, which represents the curvature of the meridional image surface and sagittal image surface of light rays of different wavelengths, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.15 mm to 0.01 mm, which indicates that the optical lens can well correct the field curvature.

[0162] Figure 24 FIG. 4-3 shows the F-Tanθ distortion curve of Example 4, which represents the F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging surface, the horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -65% to 0, the image compression in the edge angle region is relatively flat, and the clarity of the expanded image is effectively improved.

[0163] Figure 25 FIG. 4-4 shows the MTF (modulation transfer function) curve of Example 4, 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 0.3 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 of the field of view, and has good imaging quality and good detail resolution ability in both low and high frequency cases.

[0164] Figure 26 FIG. 4-5 shows the relative illumination curve of Example 4, which represents the relative illumination value of different field angles on the imaging surface, the horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 70% at the maximum half field angle, which indicates that the optical lens has good relative illumination. ​​​​​​

[0165] Figure 27 The axial aberration curve of the optical lens of embodiment 4 is shown in the figure, which represents the aberration of the optical axis at the imaging plane 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 -50 μm ~ 40 μm, which shows that the optical lens can well correct the axial aberration.

[0166] Figure 28 The curve of the axial aberration of the optical lens of embodiment 4 is shown in the figure, which represents the color difference at different image heights on the imaging plane at each wavelength relative to the central wavelength (0.55 μm), the horizontal axis represents the axial 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 axial aberration of the longest wavelength and the shortest wavelength is controlled within -2 μm ~ 8 μm, which shows that the optical lens can well correct the color difference of the edge field of view and the secondary spectrum of the entire image plane.

[0167] Embodiment 5

[0168] Please refer to Figure 29 , which is a structural schematic diagram of the optical lens provided in embodiment 5 of the present application. Compared with embodiment 1, the main difference between the two embodiments is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0169] The related parameters of each lens in the optical lens in embodiment 5 are shown in Table 5-1.

[0170] Table 5-1

[0171]

[0172]

[0173] The surface type parameters of the aspherical lens of the optical lens in embodiment 5 are shown in Table 5-2.

[0174] Table 5-2

[0175] Surface number K A B C D E F S1 -4.26E+00 0.00E+00 6.28E-03 -1.08E-03 4.73E-05 -5.86E-06 3.48E-07 S2 1.46E-01 0.00E+00 9.48E-03 5.45E-04 -1.05E-03 4.51E-04 -1.31E-04 S3 -4.84E+00 0.00E+00 -1.03E-02 7.07E-03 -4.30E-04 -3.49E-04 7.47E-05 S4 2.18E+00 0.00E+00 1.07E-02 3.73E-03 1.22E-03 -7.88E-04 1.50E-04 S7 1.63E+01 0.00E+00 -2.62E-02 3.05E-02 -3.26E-02 1.55E-02 -3.01E-03 S8 -2.12E+00 0.00E+00 1.39E-02 1.41E-03 -1.71E-03 3.40E-04 -9.75E-06 S9 -1.65E+00 0.00E+00 -1.13E-02 3.86E-03 -1.22E-03 2.17E-04 -1.63E-05 S10 -6.09E+00 0.00E+00 -4.81E-02 9.37E-04 -1.66E-04 9.28E-05 -6.70E-06 S11 -1.17E+00 0.00E+00 -6.22E-02 7.17E-03 -6.27E-04 3.41E-05 -5.51E-07

[0176] In this embodiment, the field curvature curve, F-Tanθ distortion curve, MTF curve, relative luminance curve, axial aberration curve and axial aberration curve of the optical lens are shown in Figure 30 、 Figure 31 、 Figure 32 、 Figure 33 、 Figure 34 、 Figure 35 .

[0177] Figure 30The field curvature curve of embodiment 5 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 -0.15mm~0mm, which shows that the optical lens can well correct the field curvature.

[0178] Figure 31 The F-Tanθ distortion curve of embodiment 5 is shown, which represents the F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging surface, the horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -50%~0, the image compression in the edge angle region is relatively flat, and the clarity of the expanded image is effectively improved.

[0179] Figure 32 The MTF (Modulation Transfer Function) curve of embodiment 5 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.

[0180] Figure 33 The relative illumination curve of embodiment 5 is shown, which represents the relative illumination value of different field angles on the imaging surface, the horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 70% at the maximum half field angle, which shows that the optical lens has good relative illumination.

[0181] Figure 34 The axial aberration curve of embodiment 5 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 -50μm~40μm, which shows that the optical lens can well correct the axial aberration.

[0182] Figure 35The vertical color aberration curve of embodiment 5 is shown, which represents the color aberration of each wavelength at different image heights on the imaging plane relative to the central wavelength (0.55 μm), the horizontal axis represents the vertical color aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. As can be seen from the figure, the vertical color aberration of the longest wavelength and the shortest wavelength is controlled within -2 μm ~ 10 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.

[0183] Referring to Table 6, the optical characteristics of the above-mentioned embodiments are shown, including the effective focal length f, the total optical length TTL, the aperture value FNO, the real image height IH, and the maximum field angle FOV of the optical lens, and the numerical values corresponding to each conditional expression in the embodiments.

[0184] Table 6

[0185]

[0186]

[0187] In summary of the above embodiments, the optical lens provided by the present application can effectively limit the length of the lens, which is conducive to the miniaturization of the optical lens, and through the reasonable configuration of the surface shape of each lens and the reasonable matching of the optical power, the resolving power of the optical lens is improved, the aberration is reduced, and the imaging quality of the optical lens is improved.

[0188] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0189] The above-described embodiments only express several embodiments of the present application, which are described in a more specific and detailed manner, but should not be understood as limiting the scope of the present patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the present patent 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 plane along the optical axis are: a first lens with negative refractive power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a second lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; a third lens with positive refractive power, both the object side surface and the image side surface of which are convex surfaces; a fourth lens with negative refractive power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a fifth lens with positive refractive power, both the object side surface and the image side surface of which are convex surfaces; a sixth lens with negative refractive power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; the fourth lens and the fifth lens form a cemented lens group; an effective focal length f of the optical lens and a focal length f1 of the first lens satisfy: -1.4 < f1 / f ≤ -1.31; an effective focal length f of the optical lens and a focal length f2 of the second lens satisfy: -34.5 < f2 / f < -15.0; an effective focal length f of the optical lens and a focal length f4 of the fourth lens satisfy: -1.26 ≤ f4 / f ≤ -1.

13.

2. The optical lens of claim 1, wherein, a curvature radius R3 of the object side surface of the second lens and a curvature radius R4 of the image side surface of the second lens satisfy: -20 < (R3+R4) / (R3-R4) < -10.

3. The optical lens of claim 1, wherein, a center thickness CT2 of the second lens along the optical axis and an air gap CT of the first lens to the second lens on the optical axis 12 satisfies: 0.15 < CT2 / CT 12 <0.

3.

4. The optical lens of claim 1, wherein, an optical total track length TTL of the optical lens and an effective focal length f satisfy: 4.5 < TTL / f < 5.

5.

5. The optical lens of claim 1, wherein, an effective focal length f of the optical lens, a maximum field of view FOV, and a real image height IH corresponding to the maximum field of view satisfy: 0.3 < (IH / 2) / (f*tan(FOV / 2)) < 0.

7.

6. The optical lens of claim 1, wherein, an effective focal length f of the optical lens and a real image height IH corresponding to the maximum field of view satisfy: 1.98 ≤ IH / f ≤ 2.

18.

7. The optical lens of claim 1, wherein, an effective focal length f of the optical lens and a focal length f6 of the sixth lens satisfy: -5.95 ≤ f6 / f ≤ -4.

94.

8. The optical lens of claim 1, wherein, an effective focal length f of the optical lens and a focal length f3 of the third lens satisfy: 1.5 < f3 / f < 1.

7.

9. The optical lens of claim 1, wherein, a maximum field of view FOV of the optical lens, a real image height IH corresponding to the maximum field of view, and an entrance pupil diameter D1 of the object side surface of the first lens satisfy: 0.3 < D1 / IH / tan(FOV / 2) ≤ 0.

54.

10. The optical lens of claim 1, wherein, an effective focal length f of the optical lens and a focal length f5 of the fifth lens satisfy: 0.79 ≤ f5 / f < 0.9.

Images