Optical lens

Abstract

The present invention provides an optical lens, which has a total of six lenses. Along the optical axis from the object side to the imaging surface, it successively includes: a first lens with a negative optical power, whose object side is convex and image side is concave; a second lens with a negative optical power, whose object side is convex and image side is concave; a third lens with a positive optical power, whose object side is concave and image side is convex; a fourth lens with a negative optical power, whose object side is convex and image side is concave; a fifth lens with a positive optical power, whose object side and image side are both convex; a sixth lens with a negative optical power, whose object side is convex and image side is concave; the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.5 < f3 / f < 14.5. The optical lens provided by the present invention improves the resolution of the optical lens, reduces aberration, and improves the imaging quality of the optical lens through the reasonable configuration of each lens surface type and the reasonable combination of optical powers.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and in particular to an optical lens. Background Art

[0002] As people's requirements for driving experience continue to increase, automotive optical lenses are increasingly used in intelligent driving, and the status of automotive optical lenses in the automotive-related industries continues to improve.

[0003] In-vehicle DMS system cameras are imaging cameras primarily used in the cabin. Their primary functions include driver fatigue detection and facial recognition. Existing DMS system lenses require not only a thin, lightweight, small-diameter front-end design, high pixel count, and high resolution, but also the ability to produce clear images in low-light conditions. Therefore, developing an optical lens with excellent imaging performance is crucial. Summary of the Invention

[0004] In view of the above problems, an object of the present invention is to provide an optical lens having the advantage of excellent imaging quality.

[0005] The present invention provides an optical lens, comprising six lenses, which include the following lenses in order from the object side to the imaging surface along the optical axis:

[0006] a first lens having negative optical power, wherein the object-side surface is convex and the image-side surface is concave;

[0007] a second lens having negative optical power, the object-side surface of which is convex and the image-side surface of which is concave;

[0008] The third lens has positive optical power, its object-side surface is concave and its image-side surface is convex;

[0009] a fourth lens element having negative optical power, whose object-side surface is convex and whose image-side surface is concave;

[0010] The fifth lens has positive refractive power, and both the object-side surface and the image-side surface are convex;

[0011] a sixth lens element having negative optical power, the object-side surface of which is convex and the image-side surface of which is concave;

[0012] The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.5 <f3 / f<14.5。

[0013] Further preferably, the object-side curvature radius R1 and the image-side curvature radius R2 of the first lens satisfy: 4.5<(R1+R2) / (R1-R2)<5.5.

[0014] Further preferably, the object-side curvature radius R3 and the image-side curvature radius R4 of the second lens satisfy: 100<(R3+R4) / (R3-R4)<150.

[0015] Further preferably, the total optical length TTL and the effective focal length f of the optical lens satisfy: 4.0 <TTL / f<4.5。

[0016] Further preferably, 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: 0.3<(IH / 2) / (f×tan(FOV / 2))<0.6.

[0017] Further preferably, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field angle satisfy: 1.6 <IH / f<1.8。

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -4.0 <f1 / f<-2.8。

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -3.0 <f4 / f<-1.5。

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.7 <f5 / f<1.0。

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -5.5 <f6 / f<-3.0。

[0022] The optical lens provided by the present invention can effectively limit the length of the lens, which is conducive to miniaturization of the optical lens. Through the reasonable configuration of the surface shapes of each lens and the reasonable matching of the optical focal length, the resolution of the optical lens is improved, the aberration is reduced, and the imaging quality of the optical lens is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0024] Figure 1 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

[0025] Figure 2 Graph showing the field curvature of the optical lens in Example 1 of the present invention.

[0026] Figure 3 2 is a graph showing the F-Tanθ distortion curve of the optical lens in Example 1 of the present invention.

[0027] Figure 4 This is the MTF curve of the optical lens in Example 1 of the present invention.

[0028] Figure 5 This is a relative illumination curve diagram of the optical lens in Example 1 of the present invention.

[0029] Figure 6 Graph showing the axial aberration of the optical lens in Example 1 of the present invention.

[0030] Figure 7 Graph showing the vertical axis chromatic aberration of the optical lens in Example 1 of the present invention.

[0031] Figure 8 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0032] Figure 9 Graph showing the field curvature of the optical lens in Example 2 of the present invention.

[0033] Figure 10 2 is a graph showing the F-Tanθ distortion curve of the optical lens in Example 2 of the present invention.

[0034] Figure 11 This is an MTF curve diagram of the optical lens in Example 2 of the present invention.

[0035] Figure 12 This is a relative illumination curve diagram of the optical lens in Example 2 of the present invention.

[0036] Figure 13 2 is an axial aberration curve diagram of the optical lens in Example 2 of the present invention.

[0037] Figure 14 Graph showing vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0038] Figure 15 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0039] Figure 16 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0040] Figure 17 2 is a graph showing the F-Tanθ distortion curve of the optical lens in Example 3 of the present invention.

[0041] Figure 18 This is the MTF curve of the optical lens in Example 3 of the present invention.

[0042] Figure 19 This is a relative illumination curve diagram of the optical lens in Example 3 of the present invention.

[0043] Figure 20 Graph showing the axial aberration of the optical lens in Example 3 of the present invention.

[0044] Figure 21 Graph showing vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0045] Figure 22 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0046] Figure 23 4 is a field curvature curve diagram of the optical lens in Example 4 of the present invention.

[0047] Figure 24 4 is an F-Tanθ distortion curve of the optical lens in Example 4 of the present invention.

[0048] Figure 25 This is the MTF curve of the optical lens in Example 4 of the present invention.

[0049] Figure 26 This is a relative illumination curve diagram of the optical lens in Example 4 of the present invention.

[0050] Figure 27 4 is an axial aberration curve diagram of the optical lens in Example 4 of the present invention.

[0051] Figure 28 Graph showing vertical axis chromatic aberration of the optical lens in Example 4 of the present invention.

[0052] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0053] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of embodiments of the present application and are not intended to limit the scope of the present 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.

[0054] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of the present invention.

[0055] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0056] In this article, the paraxial region refers to the area near the optical axis. If a lens surface is convex and the location of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the location of the concave surface is undefined, 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.

[0057] It should also be understood that the terms "comprises," "including," "having," "includes," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application." And, the term "exemplary" is intended to refer to an example or illustration.

[0058] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0059] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0060] The optical lens according to the embodiment of the present invention includes, in order from the object side to the image side along the optical axis, a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens, and a filter.

[0061] In some embodiments, the first lens element may have negative power to reduce the angle of incident light, effectively sharing the large object-side field of view. The first lens element has a convex object-side surface and a concave image-side surface, which helps collect as much light from the edge of the field of view as possible and feed it into the rear optical element, achieving wide-angle light collection.

[0062] In some embodiments, the second lens may have a negative optical power, with its object side being convex and its image side being concave, capable of sharing the negative optical power at the front end of the lens, thereby facilitating the reduction of excessive light deflection caused by the over-concentration of the optical power of the first lens and reducing the difficulty of chromatic aberration correction for the optical lens.

[0063] In some embodiments, the third lens may have a positive optical power, which is beneficial for converging light while reducing the light deflection angle, enabling a smooth transition of the light path. The object side of the third lens is concave and the image side is convex, which can reduce the impact of spherical aberration and astigmatism generated by the third lens itself on the optical lens and improve the imaging quality of the optical lens.

[0064] In some embodiments, the fourth lens may have a negative optical power, with its object side being convex and its image side being concave, which is beneficial for balancing various aberrations generated by the optical lens and improving the imaging quality of the optical lens.

[0065] In some embodiments, the fifth lens may have a positive optical power, which is beneficial for improving the light converging ability of the optical lens. Both the object side and the image side of the fifth lens are convex, which can reduce the spherical aberration and coma generated by the fifth lens itself and improve the imaging quality of the optical lens.

[0066] In some embodiments, the sixth lens may have a negative optical power, which is beneficial for increasing the imaging area of the optical lens and improving the imaging quality of the optical lens. The object side of the sixth lens is convex and the image side is concave, which can optimize the chromatic aberration of the optical lens and improve the imaging quality of the optical lens.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.5 < f3 / f < 14.5. Meeting the above range, by adjusting the focal length of the third lens, a larger magnification can be provided, enabling the photographed object to appear larger and with clearer details, and improving the imaging quality of the optical lens.

[0068] In some embodiments, the radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side satisfy: 4.5 < (R1 + R2) / (R1 - R2) < 5.5. Meeting the above range, by adjusting the radii of curvature of the object side and the image side of the first lens, better light control ability can be provided, reducing light interference from the side or non-optical axis direction, reducing reflection and scattering, and improving the clarity and contrast of the imaging.

[0069] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface satisfy: 100 < (R3 + R4) / (R3 - R4) < 150. Satisfying the above range, by adjusting the radii of curvature of the object side surface and the image side surface of the second lens, it is beneficial to strengthen the correction of higher-order aberrations and reduce the attenuation degree of the relative illumination of the optical lens.

[0070] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f satisfy: 4.0 < TTL / f < 4.5. Satisfying the above range can effectively limit the length of the lens and achieve miniaturization of the optical lens.

[0071] In some embodiments, the effective focal length f of the optical lens, the maximum field angle FOV, and the true image height IH corresponding to the maximum field angle satisfy: 0.3 < (IH / 2) / (f × tan(FOV / 2)) < 0.6. Satisfying the above range is beneficial for the optical lens to achieve a balance between the field angle size and the F-Tanθ distortion size, and improve the imaging quality of the optical lens.

[0072] In some embodiments, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field angle satisfy: 1.6 < IH / f < 1.8. Satisfying the above range is beneficial for the optical lens to achieve a balance between the field angle size and the F-Tanθ distortion size, and improve the imaging quality of the optical lens.

[0073] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -4.0 < f1 / f < -2.8. Satisfying the above range, by adjusting the focal length of the first lens, the field angle of the optical lens can be increased, and at the same time, the perspective and foreground emphasis effects of the optical lens can be enhanced, which helps to highlight the objects in the central field of view.

[0074] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -3.0 < f4 / f < -1.5. Satisfying the above range can make the fourth lens have an appropriate negative optical power, which is beneficial to balance various aberrations generated by the optical lens and improve the imaging quality of the optical lens.

[0075] 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 < 1.0. Satisfying the above range can make the fifth lens have an appropriate positive optical power, which can reduce the spherical aberration and coma generated by the fifth lens itself and improve the imaging quality of the optical lens.

[0076] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -5.5 < f6 / f < -3.0. Meeting the above range can endow the sixth lens with an appropriate negative optical power, which is beneficial to increasing the imaging area of the optical lens. Meanwhile, it can optimize the chromatic aberration of the optical lens and improve the imaging quality of the optical lens.

[0077] In some embodiments, the maximum field of view FOV of the optical lens satisfies: 115° < FOV < 145°. Meeting the above range can enable the optical lens to have a large field of view.

[0078] In some embodiments, the maximum field of view FOV of the optical lens and the f-number FNO satisfy: 55° < FOV / FNO < 75°. Meeting the above range is beneficial 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 obtaining more scene information and meeting the requirements of large-range detection. The realization of the large-aperture characteristic is beneficial to improving the problem of rapid decline of the relative brightness in the edge field of view, and thus is also conducive to obtaining more scene information.

[0079] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view satisfy: 2.0 < TTL / IH < 2.8. Meeting the above range can effectively balance the requirements of the image height and miniaturization of the optical lens.

[0080] In some embodiments, the true image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD satisfy: 3.0 < IH / EPD < 4.0. Meeting the above range can increase the width of the light beam entering the optical lens, improve the brightness at the image plane of the optical lens and avoid vignetting.

[0081] In some embodiments, the true image height IH corresponding to the half field of view of the optical lens θ and the true image height IH corresponding to the maximum field of view satisfy: 0.55 < IH θ / IH < 0.65. Meeting the above range can highlight the proportion of the imaging range of the central field of view in the entire imaging orientation. Compared with lenses with the same field of view angle, when matching chips of the same size, the proportion of the imaging range of the central field of view in the entire imaging range is larger, and more detailed information can be obtained.

[0082] In some embodiments, among the maximum field of view FOV of the optical lens, the true image height IH corresponding to the maximum field of view, and the clear aperture D1 of the object side surface of the first lens, they satisfy: 0.4 < D1 / IH / tan(FOV / 2) < 0.7. Meeting the above range can ensure the balance among the size, field of view angle, and image plane of the optical lens.

[0083] In some embodiments, the vector height Sag1 of the object side of the first lens and the semi-aperture d1 of the light passing through the object side of the first lens satisfy the following conditions: 0.4<Sag1 / d1<0.5; the vector height Sag2 of the image side of the first lens and the semi-aperture d2 of the light passing through the image side of the first lens satisfy the following conditions: 0.65<Sag2 / d2<0.85. Meeting the above ranges can highlight the proportion of the central field of view imaging range in the entire imaging orientation. Compared with lenses with the same field of view angle, when matching chips of the same size, the central field of view imaging range accounts for a larger proportion of the entire imaging range, thereby obtaining more detailed information. At the same time, it can reduce the deflection angle of the light at the central field of view angle, reduce the difficulty of aberration correction of the central field of view of the optical lens, and reduce the reliance on lens correction aberrations after the aperture.

[0084] In some embodiments, the fourth lens and the fifth lens can be cemented to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the decentration sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the difficulty of the optical lens processing technology and improving the assembly yield of the optical lens.

[0085] In order to make the system have better optical performance, multiple aspheric lenses are used in the lens, and the shape of each aspheric surface of the optical lens satisfies the following equation:

[0086]

[0087] Where z is the distance between the surface and the vertex in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the surface vertex, K is the quadratic surface coefficient, and A, B, C, D, E, and F are the second-order, fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order surface coefficients, respectively.

[0088] The present invention is further illustrated below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens vary; for details, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any other changes, substitutions, combinations, or simplifications that do not deviate from the novelties of the present invention shall be considered equivalent replacements and are included within the scope of protection of the present invention.

[0089] Example 1

[0090] See also Figure 1 , shown is a schematic structural diagram of the optical lens provided in Example 1 of the present invention, which includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a filter G1.

[0091] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0092] The second lens L2 has negative refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave;

[0093] The third lens L3 has positive refractive power, its object-side surface S5 is concave, and its image-side surface S6 is convex;

[0094] Aperture ST;

[0095] The fourth lens L4 has negative refractive power, its object-side surface S7 is convex, and its image-side surface S8 is concave;

[0096] The fifth lens L5 has positive refractive power, and its object-side surface S8 and image-side surface S9 are both convex;

[0097] The fourth lens L4 and the fifth lens L5 form a cemented lens group, that is, the cemented surface between the image-side surface of the fourth lens L4 and the object-side surface of the fifth lens L5 is S8;

[0098] The sixth lens L6 has negative optical power, its object-side surface S10 is convex, and its image-side surface S11 is concave; the object-side surface S12 and image-side surface S13 of the filter G1 are both flat.

[0099] The imaging surface S14 is a plane.

[0100] The relevant parameters of each lens in the optical lens in Example 1 are shown in Table 1-1.

[0101] Table 1-1

[0102]

[0103] The surface parameters of the aspheric lens of the optical lens in Example 1 are shown in Table 1-2.

[0104] Table 1-2

[0105] Face number K A B C D E F S1 -1.00E+00 0.00E+00 1.25E-03 -1.71E-03 9.54E-05 -1.55E-07 -1.49E-07 S2 -6.43E-01 0.00E+00 1.87E-03 -5.27E-03 7.12E-04 -9.64E-05 1.73E-06 S3 -8.87E+01 0.00E+00 1.05E-02 -1.25E-04 -3.10E-05 -1.02E-04 1.49E-05 S4 3.99E+01 0.00E+00 9.86E-05 3.83E-03 -2.36E-03 4.10E-04 -3.79E-05 S7 7.61E+00 0.00E+00 -2.49E-02 1.41E-02 -2.47E-02 1.25E-02 -2.68E-03 S8 -2.99E+00 0.00E+00 4.28E-02 -2.64E-02 9.83E-03 -3.73E-03 6.31E-04 S9 1.23E+00 0.00E+00 -6.74E-03 1.27E-03 -5.58E-04 1.21E-04 -1.71E-05 S10 -7.82E+00 0.00E+00 -4.34E-02 1.21E-03 -1.49E-03 3.22E-04 -5.47E-05 S11 -1.17E+01 0.00E+00 -2.00E-02 -9.24E-04 2.89E-04 -4.55E-05 2.17E-06

[0106] In this embodiment, the field curvature curve, F-Tanθ distortion curve, MTF curve, relative illumination curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown as follows: Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 shown.

[0107] Figure 2The field curvature curves for Example 1 are shown, representing the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: degrees). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within a range of -0.09mm to 0.06mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0108] Figure 3 The F-Tanθ distortion curve for Example 1 shows the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging surface. The horizontal axis represents F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within a range of -50% to 0%, and the image compression in the edge angle area is relatively smooth, effectively improving the clarity of the expanded image.

[0109] Figure 4 The MTF (Modulation Transfer Function) curve for Example 1 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.3 across the entire field of view. Within the range of 0 to 160 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0110] Figure 5 The relative illumination curve of Example 1 is shown, which represents the relative illumination values ​​at different field angles on the imaging plane. The horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 70% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0111] Figure 6 The following graph shows the axial aberration curve for Example 1, which represents the aberration on the optical axis at the imaging plane for 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 graph, the offset of the axial aberration is controlled within -50μm to 50μm, indicating that the optical lens can effectively correct axial aberration.

[0112] Figure 7The vertical chromatic aberration curve for Example 1 is shown. It plots the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for both the longest and shortest wavelengths is controlled within a range of -4 μm to 8 μm, demonstrating that this optical lens is capable of excellently correcting chromatic aberration in the peripheral field of view and the secondary spectrum across the entire image plane.

[0113] Example 2

[0114] See also Figure 8 , shown is a schematic structural diagram of the optical lens provided in Example 2 of the present invention. Compared with Example 1, this embodiment is different mainly in optical parameters such as the curvature radius of each lens surface and the lens thickness.

[0115] The relevant parameters of each lens in the optical lens in Example 2 are shown in Table 2-1.

[0116] Table 2-1

[0117]

[0118] The surface parameters of the aspheric lens of the optical lens in Example 2 are shown in Table 2-2.

[0119] Table 2-2

[0120] Face number K A B C D E F S1 -1.05E+00 0.00E+00 1.02E-03 -1.66E-03 7.96E-05 1.05E-07 -1.05E-07 S2 -6.89E-01 0.00E+00 1.19E-03 -4.60E-03 8.33E-04 -9.78E-05 -2.10E-06 S3 -3.65E+01 0.00E+00 1.04E-02 1.24E-04 3.42E-05 -1.02E-04 1.67E-05 S4 3.43E+01 0.00E+00 1.27E-03 3.81E-03 -2.43E-03 4.73E-04 -3.40E-05 S7 7.66E+00 0.00E+00 -2.81E-02 1.43E-02 -2.46E-02 1.29E-02 -3.14E-03 S8 -3.24E+00 0.00E+00 4.46E-02 -2.96E-02 9.96E-03 -3.48E-03 6.24E-04 S9 1.15E+00 0.00E+00 -5.84E-03 1.04E-03 -5.55E-04 1.36E-04 -2.02E-05 S10 -3.00E+01 0.00E+00 -4.40E-02 2.44E-03 -1.56E-03 3.30E-04 -4.78E-05 S11 -1.42E+01 0.00E+00 -2.34E-02 -6.17E-04 2.84E-04 -3.98E-05 1.48E-06

[0121] In this embodiment, the field curvature curve, F-Tanθ distortion curve, MTF curve, relative illumination curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown as follows: Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 、 Figure 14 shown.

[0122] Figure 9 The field curvature curves for Example 2 are shown, representing the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: degrees). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within a range of -0.12mm to 0mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0123] Figure 10The F-Tanθ distortion curve for Example 2 shows the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging surface. The horizontal axis represents F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within a range of -55% to 0%, and the image compression in the edge angle region is relatively smooth, effectively improving the clarity of the expanded image.

[0124] Figure 11 The MTF (Modulation Transfer Function) curve for Example 2 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.4 across the entire field of view. Within the range of 0 to 160 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0125] Figure 12 The relative illumination curve of Example 2 is shown, which represents the relative illumination values ​​at 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, indicating that the optical lens has good relative illumination.

[0126] Figure 13 The following graph shows the axial aberration curve for Example 2, which represents the aberration on the optical axis at the imaging plane for 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 graph, the offset of the axial aberration is controlled within a range of -50 μm to 40 μm, indicating that the optical lens is able to effectively correct axial aberration.

[0127] Figure 14 The vertical chromatic aberration curve for Example 2 is shown. It plots the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for both the longest and shortest wavelengths is controlled within a range of -2 μm to 10 μm, demonstrating that this optical lens is capable of excellently correcting chromatic aberration in the peripheral field of view and the secondary spectrum across the entire image plane.

[0128] Example 3

[0129] See also Figure 15 , shown is a schematic structural diagram of the optical lens provided in Example 3 of the present invention. Compared with Example 1, this embodiment is different mainly in optical parameters such as the curvature radius of each lens surface and the lens thickness.

[0130] The relevant parameters of each lens in the optical lens in Example 3 are shown in Table 3-1.

[0131] Table 3-1

[0132]

[0133]

[0134] The surface parameters of the aspheric lens of the optical lens in Example 3 are shown in Table 3-2.

[0135] Table 3-2

[0136] Face number K A B C D E F S1 -1.06E+00 0.00E+00 7.78E-04 -1.76E-03 9.30E-05 2.90E-07 -9.17E-08 S2 -7.28E-01 0.00E+00 -7.38E-03 -5.83E-03 1.10E-03 -1.12E-04 -8.69E-06 S3 -1.00E+02 0.00E+00 1.19E-02 -3.42E-04 -3.18E-04 -8.81E-05 1.62E-05 S4 2.53E+01 0.00E+00 9.75E-04 2.13E-03 -2.37E-03 4.57E-04 -2.97E-05 S7 8.16E+00 0.00E+00 -2.48E-02 1.24E-02 -2.31E-02 1.37E-02 -3.58E-03 S8 -4.06E+00 0.00E+00 4.36E-02 -2.58E-02 1.06E-02 -3.32E-03 4.25E-04 S9 1.17E+00 0.00E+00 -5.05E-03 8.87E-04 -4.86E-04 1.24E-04 -1.03E-05 S10 -4.00E+00 0.00E+00 -4.23E-02 3.30E-03 -1.55E-03 2.78E-04 -3.72E-05 S11 -1.05E+01 0.00E+00 -2.03E-02 -8.86E-04 2.09E-04 -3.25E-05 1.52E-06

[0137] In this embodiment, the field curvature curve, F-Tanθ distortion curve, MTF curve, relative illumination curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown as follows: Figure 16 、 Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 、 Figure 21 shown.

[0138] Figure 16 The field curvature curves for Example 3 are shown, representing the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: degrees). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within a range of -0.04mm to 0.02mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0139] Figure 17 The F-Tanθ distortion curve for Example 3 is shown. It represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the graph, the F-Tanθ distortion of the optical lens is controlled within a range of -70% to 0%, and image compression is relatively smooth in the edge angle region, effectively improving the clarity of the expanded image.

[0140] Figure 18The MTF (Modulation Transfer Function) curve for Example 3 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.5 across the entire field of view. Within the range of 0 to 160 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0141] Figure 19 The relative illumination curve of Example 3 is shown, which shows the relative illumination values ​​at different field angles on the imaging plane. The horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is still greater than 70% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0142] Figure 20 The following graph shows the axial aberration curve for Example 3, which represents the aberration on the optical axis at the imaging plane for 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 graph, the offset of the axial aberration is controlled within -30μm to 40μm, indicating that the optical lens can effectively correct axial aberration.

[0143] Figure 21 The vertical chromatic aberration curve for Example 3 is shown. It plots the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for both the longest and shortest wavelengths is controlled within a range of -2 μm to 10 μm, demonstrating that this optical lens is capable of excellently correcting chromatic aberration in the peripheral field of view and the secondary spectrum across the entire image plane.

[0144] Example 4

[0145] See also Figure 22 , shown is a schematic structural diagram of the optical lens provided in Example 4 of the present invention. Compared with Example 1, this embodiment is different mainly in optical parameters such as the curvature radius of each lens surface and the lens thickness.

[0146] The relevant parameters of each lens in the optical lens in Example 4 are shown in Table 4-1.

[0147] Table 4-1

[0148]

[0149]

[0150] The surface parameters of the aspheric lens of the optical lens in Example 4 are shown in Table 4-2.

[0151] Table 4-2

[0152] Face number K A B C D E F S1 -1.03E+00 0.00E+00 1.15E-03 -1.77E-03 8.93E-05 1.85E-07 -9.02E-08 S2 -7.29E-01 0.00E+00 -9.55E-03 -6.08E-03 1.12E-03 -1.09E-04 -7.88E-06 S3 -9.49E+01 0.00E+00 1.21E-02 -1.88E-04 -3.19E-04 -8.64E-05 1.55E-05 S4 2.41E+01 0.00E+00 9.94E-04 2.03E-03 -2.37E-03 4.58E-04 -2.91E-05 S7 8.27E+00 0.00E+00 -2.75E-02 1.16E-02 -2.32E-02 1.38E-02 -3.60E-03 S8 -3.52E+00 0.00E+00 3.66E-02 -2.85E-02 1.14E-02 -2.99E-03 3.42E-04 S9 1.52E+00 0.00E+00 -6.88E-03 1.06E-03 -4.07E-04 1.00E-04 -1.21E-05 S10 -3.31E+00 0.00E+00 -4.15E-02 2.25E-03 -1.49E-03 2.52E-04 -3.93E-05 S11 -1.03E+01 0.00E+00 -1.97E-02 -1.37E-03 2.43E-04 -2.82E-05 1.63E-06

[0153] In this embodiment, the field curvature curve, F-Tanθ distortion curve, MTF curve, relative illumination curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens are shown as follows: Figure 23 、 Figure 24 、 Figure 25 、 Figure 26 、 Figure 27 、 Figure 28 shown.

[0154] Figure 23 The field curvature curves for Example 4 are shown, showing the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: degrees). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within a range of -0.05mm to 0.03mm, demonstrating that the optical lens is capable of effectively correcting field curvature.

[0155] Figure 24 The F-Tanθ distortion curve for Example 4 is shown. It represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging surface. The horizontal axis represents F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within a range of -70% to 0%, and the image compression in the edge angle area is relatively smooth, effectively improving the clarity of the expanded image.

[0156] Figure 25 The MTF (Modulation Transfer Function) curve for Example 4 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this example is consistently above 0.3 across the entire field of view. Within the range of 0 to 160 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0157] Figure 26 The relative illumination curve of Example 4 is shown, which represents the relative illumination values ​​at 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 60% at the maximum half field angle, indicating that the optical lens has good relative illumination.

[0158] Figure 27 The following graph shows the axial aberration curve for Example 4, which represents the aberration on the optical axis at the imaging plane for 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 graph, the offset of the axial aberration is controlled within a range of -30μm to 25μm, indicating that the optical lens can effectively correct axial aberration.

[0159] Figure 28 The vertical chromatic aberration curve for Example 4 is shown. It plots the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for both the longest and shortest wavelengths is controlled within a range of -4 μm to 10 μm, demonstrating that this optical lens is capable of excellently correcting chromatic aberration in the peripheral field of view and the secondary spectrum across the entire image plane.

[0160] Please refer to Table 5, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture value FNO, true image height IH and maximum field of view FOV of the optical lens, as well as the numerical values ​​corresponding to each conditional expression in each embodiment.

[0161] Table 5

[0162]

[0163]

[0164] In summary, the optical lens provided by the present invention can effectively limit the length of the lens, which is conducive to the miniaturization of the optical lens. By rationally configuring the surface shapes of each lens and rationally matching the optical power, the resolution of the optical lens is improved, the aberration is reduced, and the imaging quality of the optical lens is improved.

[0165] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0166] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An optical lens, comprising six lenses, characterized in that: It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with negative optical power, whose object side is convex and image side is concave; A second lens with negative optical power, whose object side is convex and image side is concave; A third lens with positive optical power, whose object side is concave and image side is convex; A fourth lens with negative optical power, whose object side is convex and image side is concave; A fifth lens with positive optical power, whose object side and image side are both convex; A sixth lens with negative optical power, whose object side is convex and image side is concave; The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.5 < f3 / f < 14.5, and the curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side satisfy: 4.5 < (R1 + R2) / (R1 - R2) < 5.

5.

2. The optical lens according to claim 1, wherein: The maximum field of view FOV of the optical lens satisfies: 115° < FOV < 145°. The maximum field of view FOV of the optical lens and the aperture value FNO satisfy: 55° < FOV / FNO < 75°. The total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view satisfy: 2.0 < TTL / IH < 2.

8. The true image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD satisfy: 3.0 < IH / EPD < 4.

0. The true image height IH corresponding to the half field of view of the optical lens θ and the true image height IH corresponding to the maximum field of view satisfy: 0.55 < IH θ / IH < 0.

65. Among the maximum field of view FOV of the optical lens, the true image height IH corresponding to the maximum field of view, and the light passing aperture D1 of the object side surface of the first lens, they satisfy: 0.4 < D1 / IH / tan(FOV / 2) < 0.

7. The sagittal height Sag1 of the object side surface of the first lens and the half light passing aperture d1 of the object side surface of the first lens satisfy: 0.4 < Sag1 / d1 < 0.

5. The sagittal height Sag2 of the image side surface of the first lens and the half light passing aperture d2 of the image side surface of the first lens satisfy: 0.65 < Sag2 / d2 < 0.

85.

3. The optical lens according to claim 1, wherein: The curvature radius R3 of the object side of the second lens and the curvature radius R4 of the image side satisfy: 100 < (R3 + R4) / (R3 - R4) < 150.

4. The optical lens according to claim 1, wherein: The overall optical length TTL of the optical lens and the effective focal length f satisfy: 4.0 < TTL / f < 4.

5.

5. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens, the maximum field angle FOV, and the true image height IH corresponding to the maximum field angle satisfy: 0.3 < (IH / 2) / (f × tan(FOV / 2)) < 0.

6.

6. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the true image height IH corresponding to the maximum field angle satisfy: 1.6 < IH / f < 1.

8.

7. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -4.0 < f1 / f < -2.

8.

8. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -3.0 < f4 / f < -1.

5.

9. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.7 < f5 / f < 1.

0.

10. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -5.5 < f6 / f < -3.0.

Images