Optical Lenses

Abstract

The present invention discloses an optical lens including six lenses. The optical lens includes, in order from the object side to the imaging surface along the optical axis: a first lens having a negative focal refractive power with both the object-side surface and the image-side surface being concave; a second lens having a negative focal refractive power with the object-side surface being concave and the image-side surface being convex; a third lens having a positive focal refractive power with both the object-side surface and the image-side surface being convex; a fourth lens having a positive focal refractive power with both the object-side surface and the image-side surface being convex; a fifth lens having a negative focal refractive power with the object-side surface being concave and the image-side surface being convex; and a sixth lens having a positive focal refractive power with the object-side surface being convex and the image-side surface being concave. The fourth lens and the fifth lens are adhered to form an adhesive lens. The effective focal length f of the optical lens and the real image height IH corresponding to the maximum picture angle satisfy 0.55 < f / IH < 0.65.

Description

[Technical field]

[0001] This application claims priority to a Chinese application having application number 202210090900.4, filed on January 26, 2022, the contents of which are incorporated herein by reference for all purposes.

[0002] The present invention relates to the technical field of imaging lenses, in particular optical lenses. [Background technology]

[0003] In recent years, autonomous driving assistance systems have been developing rapidly, and image algorithms have also undergone a generational change. As an important component for autonomous driving assistance systems to obtain external information, automotive lenses also need to get rid of the old and absorb the good to develop new ones in order to meet current needs.

[0004] At present, traditional autonomous driving assistance systems usually rely on telephoto lenses and wide-angle lenses to obtain information in a single direction.Telephoto lenses have a long focal length but a small viewing range, and are generally used for capturing and observing objects at long distances, while wide-angle lenses have a large viewing range but a short focal length, and are generally used for capturing and observing objects at close distances.Therefore, instead of the traditional single-function lenses in autonomous driving assistance systems, it is necessary to design an optical lens that can combine the functions of telephoto lenses and wide-angle lenses, and has a large aperture, a wide viewing angle, and high resolution. Summary of the Invention [Problem to be solved by the invention]

[0005] Based on this, an object of the present invention is to provide an optical lens having the advantages of a large aperture, a wide angle of view, and high resolution. [Means for solving the problem]

[0006] To achieve the above object, the technical means of the present invention are as follows.

[0007] The optical lens including six lenses according to the present invention, in order from the object side along the optical axis toward the imaging surface, a first lens having a negative focal refractive power, where both the object-side surface and the image-side surface are concave surfaces; a second lens having a negative focal refractive power, where the object-side surface is a concave surface and the image-side surface is a convex surface; a third lens having a positive focal refractive power, where both the object-side surface and the image-side surface are convex surfaces; a fourth lens having a positive focal refractive power, where both the object-side surface and the image-side surface are convex surfaces; a fifth lens having a negative focal refractive power, where the object-side surface is a concave surface and the image-side surface is a convex surface; a sixth lens having a positive focal refractive power, where the object-side surface is a convex surface and the image-side surface is a concave surface, and includes the fourth lens and the fifth lens are adhered to form an adhesive lens, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum angle of view satisfy 0.55 < f / IH < 0.65.

[0008] The aperture HD1 of the object-side surface of the first lens corresponding to half of the maximum angle of view of the optical lens and the aperture D1 of the object-side surface of the first lens corresponding to the maximum angle of view satisfy 0.5 < HD1 / D1 < 0.6.

[0009] Preferably, the effective focal length f of the optical lens satisfies 5.9 mm < f < 6.5 mm.

[0010] Preferably, the real image height IH corresponding to the maximum angle of view of the optical lens satisfies 9.5 mm < IH < 10.5 mm.

[0011] Preferably, the aperture value of the optical lens is 1.7 < FNO < 1.9.

[0012] Preferably, the effective focal length f of the optical lens, the focal length f1 of the first lens, and the radius of curvature R1 of the object-side surface and the radius of curvature R2 of the image-side surface of the first lens satisfy -1.2 < f1 / f < -1.0 and 0.8 < (R1 + R2) / (R1 - R2) < 0.9, respectively.

[0013] Preferably, the effective focal length f of the optical lens, the focal length f2 of the second lens, and the radius of curvature R3 of the object-side surface, the radius of curvature R4 of the image-side surface, and the center thickness CT2 of the second lens satisfy -18.5 < f2 / f < -11.5 and 1.05 < R3 / (R4 + CT2) < 1.20, respectively.

[0014] Preferably, the effective focal length f of the optical lens, the focal length f3 of the third lens, and the radius of curvature R5 of the object-side surface of the third lens satisfy 2.0 < f3 / f < 2.2 and 1.10 < R5 / f3 < 1.25, respectively.

[0015] Preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy 1.2 < f4 / f < 1.9.

[0016] Preferably, the effective focal length f of the optical lens, the focal length f5 of the fifth lens, and the radius of curvature R9 of the object-side surface and the radius of curvature R10 of the image-side surface of the fifth lens satisfy -2.2 < f5 / f < -1.8 and 1.10 < R10 / (R9 + f5) < 1.35, respectively.

[0017] Preferably, the effective focal length f of the optical lens, the focal length f6 of the sixth lens, and the radius of curvature R11 of the object-side surface and the radius of curvature R12 of the image-side surface of the sixth lens satisfy 2.8 < f6 / f < 3.9 and -3.0 < (R11 + R12) / (R11 - R12) < -1.0, respectively.

Advantages of the Invention

[0018] Compared with the prior art, the beneficial effect of the present invention is to achieve the effects that the optical lens has a large aperture, a wide angle of view, and high resolution by reasonably combining the lens shapes and focal refractive powers between the lenses.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by the practice of the invention. [Brief description of the drawings]

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and will be readily understood from the following detailed description of the embodiments taken in conjunction with the accompanying drawings. [Figure 1] 1 is a schematic diagram illustrating the configuration of an optical lens according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing a field curvature curve of the optical lens according to the first embodiment of the present invention. [Diagram 3] FIG. 2 is an on-axis aberration curve diagram of the optical lens according to the first embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing a lateral chromatic aberration curve of the optical lens according to the first embodiment of the present invention. [Diagram 5] FIG. 2 is an MTF curve diagram of the optical lens according to the first embodiment of the present invention. [Figure 6] FIG. 4 is a schematic diagram illustrating the configuration of an optical lens according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a diagram showing a field curvature curve of an optical lens according to a second embodiment of the present invention. [Figure 8] FIG. 11 is a diagram showing an on-axis aberration curve of the optical lens according to the second embodiment of the present invention. [Figure 9] FIG. 11 is a diagram showing a lateral chromatic aberration curve of the optical lens according to the second embodiment of the present invention. [Figure 10] FIG. 4 is an MTF curve diagram of an optical lens according to a second embodiment of the present invention. [Figure 11] FIG. 11 is a schematic diagram illustrating the configuration of an optical lens according to a third embodiment of the present invention. [Figure 12] FIG. 11 is a diagram showing a field curvature curve of an optical lens according to a third embodiment of the present invention. [Figure 13] FIG. 11 is a diagram showing an on-axis aberration curve of an optical lens according to a third embodiment of the present invention. [Figure 14] FIG. 11 is a diagram showing a lateral chromatic aberration curve of the optical lens according to the third embodiment of the present invention. [Figure 15] FIG. 11 is an MTF curve diagram of an optical lens according to a third embodiment of the present invention. [Figure 16] FIG. 11 is a schematic diagram illustrating the configuration of an optical lens according to a fourth embodiment of the present invention. [Figure 17] FIG. 11 is a diagram showing a field curvature curve of an optical lens according to a fourth embodiment of the present invention. [Figure 18] FIG. 11 is an on-axis aberration curve diagram of the optical lens according to the fourth embodiment of the present invention. [Figure 19] FIG. 11 is a diagram showing a lateral chromatic aberration curve of the optical lens according to the fourth embodiment of the present invention. [Figure 20] FIG. 11 is an MTF curve diagram of an optical lens according to a fourth embodiment of the present invention.

[0021] The invention will be further described in the following detailed description with reference to the above-mentioned drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] In order to better understand the present application, each aspect of the present application will be described in more detail with reference to the drawings. It should be understood that these detailed descriptions are merely for the purpose of illustrating the embodiments of the present application, and are not intended to limit the scope of the present application. The same reference numerals represent the same parts throughout the present specification. The term "and / or" includes any and all combinations of one or more of the associated items.

[0023] It should be noted that in this specification, the terms "first", "second", "third" and the like are merely used to distinguish one feature from another, and are not intended to limit the features. Therefore, without departing from the gist of the present invention, the first lens described below may also be called the second lens or the third lens.

[0024] In the drawings, the thickness, size and shape of the lenses are slightly exaggerated for the sake of convenience. In particular, the spherical or aspherical shapes shown in each drawing are shown as examples. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown. The drawings are merely examples and are not drawn to scale.

[0025] In this specification, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not defined, it is indicated that the lens surface is convex at least in the paraxial region, and if a lens surface is concave and the position of the concave surface is not defined, it is indicated 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 image plane is called the image-side surface of the lens.

[0026] It should be mentioned that, unless contradictory, the embodiments and features of the embodiments of the present application can be combined with each other. The present application will be described in detail below in combination with the embodiments with reference to the drawings.

[0027] The optical lens according to the embodiment of the present application includes, in order from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens.

[0028] In some embodiments, the first lens has a negative focal power and a biconcave shape. Such focal power and shape of the first lens are advantageous in collecting as much light as possible from a wide field of view into the rear optic.

[0029] In some embodiments, the second lens has a negative focal power and a concave-convex surface shape. Such a focal power and surface shape of the second lens is advantageous for collecting the light incident after passing through the first lens, and stably transferring the movement of the light, and is advantageous for reducing the front end aperture of the optical lens, reducing the volume of the optical lens, and realizing the miniaturization of the optical lens and reducing the cost.

[0030] In some embodiments, the third lens has a positive focal power and a biconvex surface shape, which is advantageous for converging light, smoothly causing the divergent light to enter the rear, and stably transferring the movement of light.

[0031] In some embodiments, the fourth lens has a positive focal power and a biconvex surface shape, which is advantageous in that the fourth lens can focus light and smoothly guide the divergent light backward, so that the movement of the light can be more stably transferred.

[0032] In some embodiments, the fifth lens has a negative focal power and a concave-convex surface shape, which plays a role in correcting aberrations and is advantageous in avoiding excessive divergence of the rear light.

[0033] In some embodiments, the image side surface of the fourth lens and the object side surface of the fifth lens are cemented together, and the fourth lens and the fifth lens are combined to form a cemented lens, which shares the overall chromatic aberration correction of the system, effectively corrects aberrations, reduces tolerance sensitivity problems such as tilt / misalignment that occur during the assembly process of the lens unit, and improves production yields.

[0034] In some embodiments, the sixth lens has a positive focal power and a convex-concave surface shape. Such focal power and surface shape settings of the sixth lens are advantageous for effectively transmitting more light beams to the imaging surface, correcting astigmatism and curvature of field, and improving the resolution of the optical lens. The sixth lens has an aspheric lens surface, which is advantageous for making the surface shape gentle and eliminating aberrations occurring during imaging, thereby improving the imaging quality of the optical lens.

[0035] In some embodiments, in order to further improve the imaging quality of the optical lens, a diaphragm for restricting the light beam is installed between the second lens and the fourth lens. When the diaphragm is installed between the second lens and the fourth lens, it is advantageous to converge the light entering the optical system and reduce the front aperture diameter of the optical lens.

[0036] In some embodiments, the effective focal length f of the optical lens satisfies 5.9 mm < f < 6.5 mm. Satisfying the above range helps to improve the lens's ability to emphasize the main body and its ability to photograph distant scenery.

[0037] In some embodiments, the f-number of the optical lens is 1.7 < FNO < 1.9. Satisfying the above range ensures that the optical lens has both telephoto and wide-angle capabilities and can guarantee the illumination luminance in the peripheral imaging area.

[0038] In some embodiments, the image height IH corresponding to the maximum angle of view satisfies 9.5 mm < IH < 10.5 mm. Satisfying the above range is advantageous for achieving the imaging effect of a large image plane of the optical lens, having higher optical performance, and realizing compatibility with image sensors of different specifications.

[0039] In some embodiments, the angle of incidence CRA of the chief ray of the optical lens on the image plane of the full field of view satisfies 0° < CRA < 6.5°. Satisfying the above range can increase the allowable error value between the CRA of the optical lens and the CRA of the chip photosensitive element and guarantee the illuminance in the peripheral imaging area.

[0040] In some embodiments, the effective focal length f of the optical lens and the image height IH corresponding to the maximum angle of view satisfy 0.55 < f / IH < 0.65. Satisfying the above range can ensure that the optical lens has a large imaging plane and meet the imaging needs of chips with a large target surface.

[0041] In some embodiments, the sum ΣCT of the central thicknesses of all the lenses of the optical lens and the overall optical length TTL satisfy 0.55 < ΣCT / TTL < 0.70. Satisfying the above range is advantageous for shortening the overall length of the optical lens.

[0042] In some embodiments, the aperture HD1 of the object-side surface of the first lens corresponding to half of the maximum angle of view of the optical lens and the aperture D1 of the object-side surface of the first lens corresponding to the maximum angle of view satisfy 0.5 < HD1 / D1 < 0.6. Satisfying the above range ensures that the central field of view of the optical lens is concentrated near the optical axis, can reduce coma aberration and astigmatism as much as possible, and can obtain a larger illuminance for the peripheral field of view.

[0043] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy -1.2 < f1 / f < -1.0. Satisfying the above range can give the first lens a small negative focal refractive power, which is advantageous for increasing the optical back focal length of the lens.

[0044] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy -18.5 < f2 / f < -11.5. Satisfying the above range can give the second lens a large negative focal refractive power, which is advantageous for balancing the astigmatism and field curvature of the optical lens.

[0045] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy 2.0 < f3 / f < 2.2. Satisfying the above range can give the third lens a small positive focal refractive power, which is advantageous for balancing various aberrations of the optical lens.

[0046] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy 1.2 < f4 / f < 1.9. Satisfying the above range can give the fourth lens a small positive focal refractive power, which is advantageous for balancing various aberrations of the optical lens.

[0047] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy -2.2 < f5 / f < -1.8. When the above range is satisfied, the fifth lens can be given a small negative focal refractive power, which is advantageous for correcting the aberration caused by the front lens group and avoiding excessive divergence of the rear light.

[0048] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy 2.8 < f6 / f < 3.9. When the above range is satisfied, the sixth lens can be given a large positive focal refractive power, which is advantageous for balancing the spherical aberration and field curvature of the optical lens.

[0049] In some embodiments, the radius of curvature R1 of the object-side surface and the radius of curvature R2 of the image-side surface of the first lens of the optical lens satisfy 0.8 < (R1 + R2) / (R1 - R2) < 0.9. When the above range is satisfied, it is advantageous to increase the angle of view of the optical lens, balance the spherical aberration and field curvature of the optical lens, and improve the imaging quality of the optical lens.

[0050] In some embodiments, the radius of curvature R3 of the object-side surface, the radius of curvature R4 of the image-side surface of the second lens of the optical lens, and the central thickness CT2 of the second lens satisfy 1.05 < R3 / (R4 + CT2) < 1.20. When the above range is satisfied, it is advantageous to make the shapes of the object-side surface and the image-side surface of the second lens closer to concentric circles, balance the astigmatism and field curvature generated by the second lens, and improve the imaging quality of the optical lens.

[0051] In some embodiments, the radius of curvature R5 of the object-side surface of the third lens of the optical lens and the focal length f3 of the third lens satisfy 1.10 < R5 / f3 < 1.25. When the above range is satisfied, it is advantageous to reduce the sensitivity of the third lens, balance the various aberrations of the optical lens, and improve the imaging quality of the optical lens.

[0052] In some embodiments, the radius of curvature R9 of the object-side surface of the fifth lens of the optical lens, the radius of curvature R10 of the image-side surface, and the focal length f5 of the fifth lens satisfy 1.10 < R10 / (R9 + f5) < 1.35. When the above range is satisfied, it is advantageous for controlling the refraction angle of the light beam at the fifth lens, balancing various aberrations generated at the fifth lens, and improving the imaging quality of the optical lens.

[0053] In some embodiments, the radius of curvature R11 of the object-side surface of the sixth lens of the optical lens and the radius of curvature R12 of the image-side surface satisfy -2.0 < (R11 + R12) / (R11 - R12) < -1.0. When the above range is satisfied, the image-side surface of the sixth lens becomes gentle, optimizing the distortion aberration at the periphery of the optical lens, balancing the field curvature of the optical lens, correcting the astigmatism, and improving the imaging quality of the optical lens.

[0054] In some embodiments, the central thickness CT3 of the third lens of the optical lens and the overall optical length TTL satisfy 0.08 ≤ CT3 / TTL ≤ 0.26. When the above range is satisfied, it is advantageous for achieving the purpose of correcting the field curvature by the thick third lens.

[0055] In some embodiments, the central thickness CT4 of the fourth lens of the optical lens and the overall optical length TTL satisfy 0.11 ≤ CT4 / TTL ≤ 0.16. When the above range is satisfied, it is advantageous for achieving the purpose of correcting the field curvature by the thick fourth lens.

[0056] In some embodiments, the central thickness CT6 of the sixth lens of the optical lens and the overall optical length TTL satisfy 0.11 ≤ CT6 / TTL ≤ 0.2. When the above range is satisfied, it is advantageous for achieving the purpose of correcting the field curvature by the thick sixth lens.

[0057] To endow the system with better optical performance, the lens uses a plurality of aspherical lenses, and the shape of each aspherical surface of the above optical lens satisfies the following formula.

[0058]

number

[0059] Here, z is the distance in the optical axis direction between the curved surface and the apex of the curved surface, h is the distance from the optical axis to the curved surface, c is the curvature of the apex of the curved surface, K is a quadratic surface coefficient, and A, B, C, D, E, and F are quadratic, quartic, 6th, 8th, 10th, and 12th order surface coefficients, respectively.

[0060] The present invention will be further described below by dividing it into several examples. In each example, the thickness, curvature radius, and material selection of each lens of the optical lens are different, and the specific differences can be referred to the parameter table of each example. The following examples are only preferred embodiments of the present invention, and the embodiments of the present invention are not limited to the following examples. Any other changes, substitutions, combinations, or simplifications made without departing from the novel aspects of the present invention should be regarded as equivalent substitution forms and are included in the protection scope of the present invention.

[0061] Example 1 FIG. 1 shows a schematic configuration diagram of an optical lens according to a first embodiment of the present invention. As shown in the figure, the optical lens includes, in order from the object side toward the image plane along the optical axis, a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, an optical filter G1, and a protective glass G2.

[0062] The first lens L1 has negative focal refractive power, and its object-side surface S1 is concave and its image-side surface S2 is concave; the second lens L2 has negative focal refractive power, and its object-side surface S3 is concave and its image-side surface S4 is convex, and is an aperture ST; the third lens L3 has positive focal refractive power, and its object-side surface S5 and its image-side surface S6 are both convex; the fourth lens L4 has positive focal refractive power, and its object-side surface S7 and its image-side surface S8 are both convex; the fifth lens L5 has negative focal refractive power, and its object-side surface S9 is concave and its image-side surface S10 is convex; the sixth lens L6 has positive focal refractive power, and its object-side surface S11 is convex and its image-side surface S12 is concave; and the fourth lens L4 and the fifth lens L5 may be bonded together to form a bonded lens.

[0063] The parameters of each lens of the optical lens in Example 1 are as shown in Table 1-1.

[0064] Table 1-1 [Table 1]

[0065] The parameters of the surface shape of the aspheric lens of the optical lens in Example 1 are as shown in Table 1-2.

[0066] Table 1-2 [Table 2]

[0067] In this embodiment, the field curvature curve, axial aberration curve, lateral chromatic aberration curve, and MTF curve of the optical lens are as shown in FIG. 2, FIG. 3, FIG. 4, and FIG. 5, respectively.

[0068] 2 shows the field curvature curves indicating the degree of curvature at the meridional and sagittal image planes of light of different wavelengths in Example 1, where the horizontal axis indicates the shift amount (unit: millimeters) and the vertical axis indicates the half angle of view (unit: °). As can be seen from the figure, the field curvatures at the meridional and sagittal image planes are controlled within ±0.03 mm, which indicates that the field curvature of the optical lens is well corrected.

[0069] 3 shows the axial aberration curve showing the aberration on the optical axis at the image plane of Example 1, where the horizontal axis shows the axial aberration value (unit: millimeter) and the vertical axis shows the normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ±0.015 mm, which indicates that the optical lens can effectively correct the axial aberration.

[0070] 4 shows the magnification chromatic aberration curves showing the chromatic aberration at different image heights on the imaging plane of each wavelength relative to the central wavelength (0.55 micrometers) of Example 1, the horizontal axis shows the magnification chromatic aberration value (unit: micrometer) of each wavelength relative to the central wavelength, and the vertical axis shows the normalized angle of view. As can be seen from the figure, the magnification chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±5 micrometers, which indicates that the optical lens can effectively correct the chromatic aberration of the peripheral field and the secondary spectrum of the entire image plane.

[0071] 5 shows MTF curves showing the lens imaging modulation degree at different spatial frequencies in each visual field of Example 1, where the horizontal axis shows spatial frequency (unit: lp / mm) and the vertical axis shows MTF value. As can be seen from the figure, the MTF value of this example is 0.5 or more in all visual fields, and the MTF curve drops smoothly and uniformly from the central visual field to the peripheral visual field within the range of (0 to 120) lp / mm, and has good imaging quality and good detailed resolution at both low and high frequencies.

[0072] Example 2 FIG. 6 shows a schematic configuration diagram of an optical lens according to a second embodiment of the present invention. As shown in the figure, the optical lens includes, in order from the object side toward the image plane along the optical axis, 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, an optical filter G1, and a protective glass G2.

[0073] The first lens L1 has negative focal power, its object side surface S1 is concave and its image side surface S2 is concave; the second lens L2 has negative focal power, its object side surface S3 is concave and its image side surface S4 is convex; the third lens L3 has positive focal power, its object side surface S5 and its image side surface S6 are both convex and form an aperture ST; the fourth lens L4 has positive focal power, its object side surface S7 and its image side surface S8 are both convex; the fifth lens L5 has negative focal power, its object side surface S9 is concave and its image side surface S10 is convex; the sixth lens L6 has positive focal power, its object side surface S11 is convex and its image side surface S12 is concave; and the fourth lens L4 and the fifth lens L5 are bonded together to form a bonded lens.

[0074] The parameters of each lens of the optical lens in Example 2 are as shown in Table 2-1.

[0075] Table 2-1 [Table 3]

[0076] The parameters of the surface shape of the aspheric lens of the optical lens in Example 2 are as shown in Table 2-2.

[0077] Table 2-2 [Table 4]

[0078] In this embodiment, the field curvature curve, axial aberration curve, lateral chromatic aberration curve, and MTF curve of the optical lens are as shown in FIGS. 7, 8, 9, and 10, respectively.

[0079] 7 shows the field curvature curves indicating the degree of curvature at the meridional and sagittal image planes of light of different wavelengths in Example 2, where the horizontal axis indicates the shift amount (unit: millimeters) and the vertical axis indicates the half angle of view (unit: °). As can be seen from the figure, the field curvature at the meridional and sagittal image planes is controlled within ±0.04 mm, which indicates that the field curvature of the optical lens is well corrected.

[0080] 8 shows the axial aberration curve showing the aberration on the optical axis at the image plane of Example 2, where the horizontal axis shows the axial aberration value (unit: millimeter) and the vertical axis shows the normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ±0.02 millimeters, which indicates that the optical lens can effectively correct the axial aberration.

[0081] 9 shows the magnification chromatic aberration curves showing the chromatic aberration at different image heights on the imaging plane of each wavelength relative to the central wavelength (0.55 micrometers) of Example 2, the horizontal axis shows the magnification chromatic aberration value (unit: micrometer) of each wavelength relative to the central wavelength, and the vertical axis shows the normalized angle of view. As can be seen from the figure, the magnification chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±5 micrometers, which indicates that the optical lens can effectively correct the chromatic aberration of the peripheral field and the secondary spectrum of the entire image plane.

[0082] 10 shows MTF curves showing the lens imaging modulation degree at different spatial frequencies in each visual field of Example 2, with the horizontal axis showing spatial frequency (unit: lp / mm) and the vertical axis showing MTF value. As can be seen from the figure, the MTF value of this example is 0.5 or more in all visual fields, and the MTF curve drops uniformly and smoothly from the central visual field to the peripheral visual field within the range of (0 to 120) lp / mm, and has good imaging quality and good detailed resolution at both low and high frequencies.

[0083] Example 3 FIG. 11 shows a schematic configuration diagram of an optical lens according to Example 3 of the present invention. As shown in the figure, the optical lens includes, in order from the object side toward the image plane along the optical axis, 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, an optical filter G1, and a protective glass G2.

[0084] The first lens L1 has negative focal power, its object side surface S1 is concave and its image side surface S2 is concave; the second lens L2 has negative focal power, its object side surface S3 is concave and its image side surface S4 is convex; the third lens L3 has positive focal power, its object side surface S5 and its image side surface S6 are both convex and form an aperture ST; the fourth lens L4 has positive focal power, its object side surface S7 and its image side surface S8 are both convex; the fifth lens L5 has negative focal power, its object side surface S9 is concave and its image side surface S10 is convex; the sixth lens L6 has positive focal power, its object side surface S11 is convex and its image side surface S12 is concave; and the fourth lens L4 and the fifth lens L5 are bonded together to form a bonded lens.

[0085] The parameters of each lens of the optical lens in Example 3 are as shown in Table 3-1.

[0086] Table 3-1 [Table 5]

[0087] The parameters of the surface shape of the aspheric lens of the optical lens in Example 3 are as shown in Table 3-2.

[0088] Table 3-2 [Table 6]

[0089] In this embodiment, the field curvature curve, axial aberration curve, lateral chromatic aberration curve, and MTF curve of the optical lens are as shown in FIGS. 12, 13, 14, and 15, respectively.

[0090] 12 shows the field curvature curves indicating the degree of curvature at the meridional and sagittal image planes of light of different wavelengths in Example 3, where the horizontal axis indicates the shift amount (unit: millimeters) and the vertical axis indicates the half angle of view (unit: °). As can be seen from the figure, the field curvatures at the meridional and sagittal image planes are controlled within ±0.03 mm, which indicates that the field curvature of the optical lens is well corrected.

[0091] 13 shows an axial aberration curve showing the aberration on the optical axis at the image plane of Example 3, where the horizontal axis shows the axial aberration value (unit: millimeter) and the vertical axis shows the normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ±0.02 millimeters, which indicates that the optical lens can effectively correct the axial aberration.

[0092] 14 shows the chromatic aberration curves of magnification at different image heights on the image plane of each wavelength relative to the central wavelength (0.55 micrometers) of Example 3, the horizontal axis shows the chromatic aberration value (unit: micrometer) of each wavelength relative to the central wavelength, and the vertical axis shows the normalized angle of view. As can be seen from the figure, the chromatic aberration of magnification of the longest wavelength and the shortest wavelength is controlled within ±6 micrometers, which indicates that the optical lens can effectively correct the chromatic aberration of peripheral vision and the secondary spectrum of the entire image plane.

[0093] 15 shows MTF curves showing the lens imaging modulation degree at different spatial frequencies in each visual field of Example 3, where the horizontal axis shows spatial frequency (unit: lp / mm) and the vertical axis shows MTF value. As can be seen from the figure, the MTF value of this example is 0.5 or more in all visual fields, and the MTF curve drops smoothly and uniformly from the central visual field to the peripheral visual field within the range of (0 to 120) lp / mm, and has good imaging quality and good detailed resolution at both low and high frequencies.

[0094] Example 4 FIG. 16 shows a schematic configuration diagram of an optical lens according to a fourth embodiment of the present invention. As shown in the figure, the optical lens includes, in order from the object side toward the image plane along the optical axis, 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, an optical filter G1, and a protective glass G2.

[0095] The first lens L1 has negative focal power, its object side surface S1 is concave and its image side surface S2 is concave; the second lens L2 has negative focal power, its object side surface S3 is concave and its image side surface S4 is convex; the third lens L3 has positive focal power, its object side surface S5 and its image side surface S6 are both convex and form an aperture ST; the fourth lens L4 has positive focal power, its object side surface S7 and its image side surface S8 are both convex; the fifth lens L5 has negative focal power, its object side surface S9 is concave and its image side surface S10 is convex; the sixth lens L6 has positive focal power, its object side surface S11 is convex and its image side surface S12 is concave; and the fourth lens L4 and the fifth lens L5 are bonded together to form a bonded lens.

[0096] The parameters of each lens of the optical lens in Example 4 are as shown in Table 4-1.

[0097] Table 4-1 [Table 7]

[0098] The parameters of the surface shape of the aspheric lens of the optical lens in Example 4 are as shown in Table 4-2.

[0099] Table 4-2 [Table 8]

[0100] In this embodiment, the field curvature curve, axial aberration curve, lateral chromatic aberration curve, and MTF curve of the optical lens are as shown in FIGS. 17, 18, 19, and 20, respectively.

[0101] 17 shows the field curvature curves indicating the degree of curvature at the meridional and sagittal image planes of light of different wavelengths in Example 4, where the horizontal axis indicates the shift amount (unit: millimeters) and the vertical axis indicates the half angle of view (unit: °). As can be seen from the figure, the field curvatures at the meridional and sagittal image planes are controlled within ±0.03 mm, which indicates that the field curvature of the optical lens is well corrected.

[0102] 18 shows the axial aberration curve showing the aberration on the optical axis at the image plane of Example 4, where the horizontal axis shows the axial aberration value (unit: millimeter) and the vertical axis shows the normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within ±0.02 millimeters, which indicates that the optical lens can effectively correct the axial aberration.

[0103] 19 shows the magnification chromatic aberration curves showing the chromatic aberration at different image heights on the imaging plane of each wavelength with respect to the central wavelength (0.55 micrometers) of Example 4, the horizontal axis shows the magnification chromatic aberration value (unit: micrometer) of each wavelength with respect to the central wavelength, and the vertical axis shows the normalized angle of view. As can be seen from the figure, the magnification chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±5 micrometers, which indicates that the optical lens can effectively correct the chromatic aberration of the peripheral field and the secondary spectrum of the entire image plane.

[0104] 20 shows MTF curves showing the lens imaging modulation degree at different spatial frequencies in each visual field of Example 4, with the horizontal axis showing spatial frequency (unit: lp / mm) and the vertical axis showing MTF value. As can be seen from the figure, the MTF value of this example is 0.5 or more in all visual fields, and the MTF curve drops uniformly and smoothly from the central visual field to the peripheral visual field within the range of (0 to 120) lp / mm, and has good imaging quality and good detailed resolution at both low and high frequencies.

[0105] Table 5 shows optical characteristics corresponding to each of the above examples. As shown in the table, the optical characteristics include the effective focal length f of the optical lens, the total optical length TTL, the aperture value FNO, the real image height IH, and the angle of view FOV, as well as numerical values ​​corresponding to each conditional expression in the above examples.

[0106] Table 5 [Table 9]

[0107] As described above, the embodiment of the present invention achieves the effects of a large aperture of the optical lens, a wide angle of view, and high resolution by rationally combining the lens shape and focal refractive power between each lens.

[0108] The above examples merely show some embodiments of the present invention, and although the description is specific and detailed, it should not be understood as limiting the scope of the present invention. It should be noted that those skilled in the art can make some modifications and improvements without departing from the spirit of the present invention, and all of these are within the scope of protection of the present invention. Therefore, the scope of protection of the present invention is subject to the scope of the attached claims.

Claims

1. An optical lens including six lenses, which are arranged in the following order along the optical axis from the object side to the image plane: a first lens having a negative focal power, the first lens having a concave object-side surface and a concave image-side surface; a second lens having a negative focal power, the second lens having a concave object-side surface and a convex image-side surface; a third lens having a positive focal power, the object-side surface and the image-side surface of which are both convex; a fourth lens having a positive focal power, the object-side surface and the image-side surface of which are both convex; a fifth lens having a negative focal power, the fifth lens having a concave object-side surface and a convex image-side surface; a sixth lens having a positive focal power, the sixth lens having a convex object-side surface and a concave image-side surface; the fourth lens and the fifth lens are bonded to each other to form a bonded lens; an effective focal length f of the optical lens and a real image height IH corresponding to a maximum angle of view satisfy 0.55<f / IH<0.65; an aperture HD1 of an object-side surface of a first lens corresponding to half the maximum angle of view of the optical lens and an aperture D1 of the object-side surface of the first lens corresponding to the maximum angle of view satisfy 0.5<HD1 / D1<0.

6.

2. The optical lens according to claim 1 , wherein an effective focal length f of the optical lens satisfies 5.9 mm<f<6.5 mm.

3. 2. The optical lens according to claim 1, wherein a real image height IH corresponding to a maximum angle of view of the optical lens satisfies 9.5 mm<IH<10.5 mm.

4. 2. The optical lens according to claim 1, wherein the aperture value of the optical lens is 1.7<FNO<1.

9.

5. 2. The optical lens according to claim 1, wherein an effective focal length f of the optical lens, a focal length f1 of the first lens, a radius of curvature R1 of the object-side surface of the first lens, and a radius of curvature R2 of the image-side surface thereof satisfy −1.2<f1 / f<−1.0 and 0.8<(R1+R2) / (R1−R2)<0.9, respectively.

6. 2. The optical lens according to claim 1, wherein an effective focal length f of the optical lens, a focal length f2 of the second lens, a radius of curvature R3 of the object-side surface of the second lens, a radius of curvature R4 of the image-side surface, and a center thickness CT2 of the second lens satisfy −18.5<f2 / f<−11.5 and 1.05<R3 / (R4+CT2)<1.20, respectively.

7. 2. The optical lens according to claim 1, wherein an effective focal length f of the optical lens, a focal length f3 of the third lens, and a radius of curvature R5 of the object-side surface of the third lens satisfy 2.0<f3 / f<2.2 and 1.10<R5 / f3<1.25, respectively.

8. 2. The optical lens according to claim 1, wherein an effective focal length f of the optical lens and a focal length f4 of the fourth lens satisfy 1.2<f4 / f<1.

9.

9. The optical lens according to claim 1, wherein an effective focal length f of the optical lens, a focal length f5 of the fifth lens, a radius of curvature R9 of the object-side surface of the fifth lens, and a radius of curvature R10 of the image-side surface of the fifth lens satisfy −2.2<f5 / f<−1.8 and 1.10<R10 / (R9+f5)<1.35, respectively.

10. The optical lens according to claim 1, characterized in that an effective focal length f of the optical lens, a focal length f6 of the sixth lens, and a radius of curvature R11 of the object-side surface of the sixth lens and a radius of curvature R12 of the image-side surface thereof respectively satisfy 2.8<f6 / f<3.9 and -3.0<(R11+R12) / (R11-R12)<-1.0.

Images