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, and in particular to optical lenses. [Background technology]

[0003] In recent years, autonomous driving assistance systems have been developing rapidly, and image algorithms have undergone a generational change. As an important component for autonomous driving assistance systems to acquire external information, automotive lenses also need to be developed by discarding the old and incorporating the good to meet current needs.

[0004] Currently, conventional automated driving assistance systems generally rely on telephoto and wide-angle lenses to acquire information in a single direction. Telephoto lenses have a long focal length but a small field of view and are generally used to capture and observe objects at long distances, while wide-angle lenses have a large field of view but a short focal length and are generally used to capture and observe objects at close distances. Therefore, instead of the traditional multiple lenses with a single function in automated driving assistance systems, it is necessary to design an optical lens that can combine the functions of a telephoto and wide-angle lens, and has a large aperture, a wide field of view, 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 picture angle 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 picture angle of the optical lens and the aperture D1 of the object-side surface of the first lens corresponding to the maximum picture angle 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 picture angle 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 curvature radius R1 of the object-side surface and the curvature radius 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, the curvature radius R3 of the object-side surface of the second lens, the curvature radius 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 curvature radius 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, the curvature radius R9 of the object-side surface of the fifth lens, and the curvature radius R10 of the image-side surface 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, the curvature radius R11 of the object-side surface of the sixth lens, and the curvature radius R12 of the image-side surface 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 of a large aperture, a wide angle of view, and high resolution of the optical lens 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 practice of the invention. [Brief explanation of the drawings]

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

[0022] For a better understanding of 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 explaining 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 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," etc. are used merely to distinguish one feature from another, and do not 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 ease of explanation. Specifically, 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 the region near the optical axis. When a lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region. When a lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the image plane is called the image-side surface of the lens.

[0026] It should be noted 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 surface shape, which is advantageous for 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, which is advantageous for collecting the incident light after passing through the first lens and stably transferring the movement of the light, and is also advantageous for reducing the front aperture and volume of the optical lens, thereby realizing a compact optical lens and reducing costs.

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

[0032] In some embodiments, the fifth lens has a negative focal power and a concave-convex surface shape, which is advantageous for correcting aberrations and preventing 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. By combining the fourth lens and the fifth lens to form a cemented lens, the overall chromatic aberration correction of the system is shared, aberrations are effectively corrected, tolerance sensitivity issues such as tilt / misalignment that occur during the assembly process of the lens unit are reduced, and production yields are improved.

[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 to the imaging plane, correcting astigmatism and field curvature, and improving the resolving power of the optical lens. The sixth lens has an aspherical lens surface, which provides a gentle surface shape and eliminates aberrations that occur 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, an aperture for restricting the light beam is installed between the second lens and the fourth lens. When the aperture 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 ability of the lens to emphasize the main body and the ability to photograph distant scenery.

[0037] In some embodiments, the aperture value 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 region.

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

[0039] In some embodiments, the incident angle 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 region.

[0040] In some embodiments, the effective focal length f of the optical lens and the image height IH corresponding to the maximum picture angle 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 plane.

[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. When the above range is satisfied, it 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. When the above range is satisfied, it is possible to ensure that the central field of view of the optical lens is concentrated near the optical axis, reduce coma aberration and astigmatism as much as possible, and 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. When the above range is satisfied, it is possible to 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. When the above range is satisfied, it is possible to 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. When the above range is satisfied, it is possible to 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. When the above range is satisfied, it is possible to 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 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 vertex of the curved surface, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is a quadratic surface coefficient, and A, B, C, D, E, and F are quadratic, quartic, hexagonal, octagonal, decagonal, and twelfth-order surface coefficients, respectively.

[0060] The present invention will be further described below through several examples. In each example, the thickness, curvature radius, and material selection of each optical lens are different, and specific differences can be seen in the parameter table of each example. The following examples are merely 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 considered as equivalent substitutions and fall within 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 to 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 power, and its object-side surface S1 is concave, and its image-side surface S2 is concave. The second lens L2 has negative focal power, and its object-side surface S3 is concave, and its image-side surface S4 is convex, and is an aperture stop ST. The third lens L3 has positive focal power, and its object-side surface S5 and its image-side surface S6 are both convex. The fourth lens L4 has positive focal power, and its object-side surface S7 and its image-side surface S8 are both convex. The fifth lens L5 has negative focal power, and its object-side surface S9 is concave, and its image-side surface S10 is convex. The sixth lens L6 has positive focal power, and its object-side surface S11 is convex, and its image-side surface S12 is concave. The fourth lens L4 and the fifth lens L5 may be cemented together to form a cemented 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 aspherical 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 FIGS. 2, 3, 4, and 5, respectively.

[0068] 2 shows field curvature curves indicating the degree of curvature at the meridional and sagittal image planes for 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: degrees). As can be seen from the figure, the field curvature at the meridional and sagittal image planes is controlled within ±0.03 mm, which indicates that the field curvature of the optical lens is well corrected.

[0069] 3 shows an axial aberration curve showing the aberration on the optical axis at the image plane of Example 1, where the horizontal axis indicates the axial aberration value (unit: millimeters) and the vertical axis indicates 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 chromatic aberration curves of magnification at different image heights on the image plane for each wavelength relative to the central wavelength (0.55 micrometers) of Example 1, where the horizontal axis indicates the chromatic aberration value (unit: micrometers) of magnification at each wavelength relative to the central wavelength, and the vertical axis indicates the normalized angle of view. As can be seen from the figure, the chromatic aberration of magnification at the longest and shortest wavelengths 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 indicating the lens imaging modulation degree at different spatial frequencies in each field of view of Example 1, with the horizontal axis representing spatial frequency (unit: lp / mm) and the vertical axis representing MTF value. As can be seen from the figure, the MTF value of this example is 0.5 or higher throughout the entire field of view, and the MTF curve drops smoothly and uniformly from the central field to the peripheral field within the range of (0 to 120) lp / mm, providing good imaging quality and good detail 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, and its object-side surface S1 is concave, and its image-side surface S2 is concave. The second lens L2 has negative focal power, and its object-side surface S3 is concave, and its image-side surface S4 is convex. The third lens L3 has positive focal power, and its object-side surface S5 and image-side surface S6 are both convex, and is an aperture stop ST. The fourth lens L4 has positive focal power, and its object-side surface S7 and image-side surface S8 are both convex. The fifth lens L5 has negative focal power, and its object-side surface S9 is concave, and its image-side surface S10 is convex. The sixth lens L6 has positive focal power, and its object-side surface S11 is convex, and its image-side surface S12 is concave. The fourth lens L4 and the fifth lens L5 are cemented together to form a cemented 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 aspherical lens of the optical lens in Example 2 are as shown in Table 2-2.

[0077] Table 2-2 [Table 4]

[0078] In this example, 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 field curvature curves indicating the degree of curvature at the meridional and sagittal image planes for 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 indicates the axial aberration value (unit: millimeters) and the vertical axis indicates 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 chromatic aberration curves of magnification at different image heights on the image plane for each wavelength relative to the central wavelength (0.55 micrometers) in Example 2, where the horizontal axis indicates the chromatic aberration value (unit: micrometers) for each wavelength relative to the central wavelength, and the vertical axis indicates the normalized angle of view. As can be seen from the figure, the chromatic aberration of magnification at the longest and shortest wavelengths 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 indicating the lens imaging modulation degree at different spatial frequencies in each field of view for Example 2, with the horizontal axis representing spatial frequency (unit: lp / mm) and the vertical axis representing MTF value. As can be seen from the figure, the MTF value for this example is 0.5 or greater throughout the entire field of view, and the MTF curve drops smoothly and uniformly from the central field to the peripheral field within the range of (0 to 120) lp / mm, providing good imaging quality and good detail resolution at both low and high frequencies.

[0083] Example 3 FIG. 11 shows a schematic configuration diagram of an optical lens according to a third 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.

[0084] The first lens L1 has negative focal power, and its object-side surface S1 is concave, and its image-side surface S2 is concave. The second lens L2 has negative focal power, and its object-side surface S3 is concave, and its image-side surface S4 is convex. The third lens L3 has positive focal power, and its object-side surface S5 and image-side surface S6 are both convex, and is an aperture stop ST. The fourth lens L4 has positive focal power, and its object-side surface S7 and image-side surface S8 are both convex. The fifth lens L5 has negative focal power, and its object-side surface S9 is concave, and its image-side surface S10 is convex. The sixth lens L6 has positive focal power, and its object-side surface S11 is convex, and its image-side surface S12 is concave. The fourth lens L4 and the fifth lens L5 are cemented together to form a cemented 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 aspherical lens of the optical lens in Example 3 are as shown in Table 3-2.

[0088] Table 3-2 [Table 6]

[0089] In this example, 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 field curvature curves indicating the degree of curvature at the meridional and sagittal image planes for 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: degrees). As can be seen from the figure, the field curvature at the meridional and sagittal image planes is 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 indicates the axial aberration value (unit: millimeters) and the vertical axis indicates 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 for each wavelength relative to the central wavelength (0.55 micrometers) in Example 3, where the horizontal axis indicates the chromatic aberration value (unit: micrometer) for each wavelength relative to the central wavelength, and the vertical axis indicates the normalized angle of view. As can be seen from the figure, the chromatic aberration of magnification at the longest and shortest wavelengths is controlled within ±6 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.

[0093] 15 shows MTF curves indicating the lens imaging modulation degree at different spatial frequencies in each field of view for Example 3, with the horizontal axis representing spatial frequency (unit: lp / mm) and the vertical axis representing MTF value. As can be seen from the figure, the MTF value for this example is 0.5 or greater throughout the entire field of view, and the MTF curve drops smoothly and uniformly from the central field to the peripheral field within the range of (0 to 120) lp / mm, providing good imaging quality and good detail 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, and its object-side surface S1 is concave, and its image-side surface S2 is concave. The second lens L2 has negative focal power, and its object-side surface S3 is concave, and its image-side surface S4 is convex. The third lens L3 has positive focal power, and its object-side surface S5 and image-side surface S6 are both convex, and is an aperture stop ST. The fourth lens L4 has positive focal power, and its object-side surface S7 and image-side surface S8 are both convex. The fifth lens L5 has negative focal power, and its object-side surface S9 is concave, and its image-side surface S10 is convex. The sixth lens L6 has positive focal power, and its object-side surface S11 is convex, and its image-side surface S12 is concave. The fourth lens L4 and the fifth lens L5 are cemented together to form a cemented 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 aspherical lens of the optical lens in Example 4 are as shown in Table 4-2.

[0099] Table 4-2 [Table 8]

[0100] In this example, 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 field curvature curves indicating the degree of curvature at the meridional and sagittal image planes for 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: degrees). As can be seen from the figure, the field curvature at the meridional and sagittal image planes is controlled within ±0.03 mm, which indicates that the field curvature of the optical lens is well corrected.

[0102] 18 shows an axial aberration curve showing the aberration on the optical axis at the image plane of Example 4, where the horizontal axis indicates the axial aberration value (unit: millimeters) and the vertical axis indicates 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 chromatic aberration curves of magnification at different image heights on the image plane for each wavelength relative to the central wavelength (0.55 micrometers) of Example 4, where the horizontal axis indicates the chromatic aberration value (unit: micrometer) of magnification at each wavelength relative to the central wavelength, and the vertical axis indicates the normalized angle of view. As can be seen from the figure, the chromatic aberration of magnification at the longest and shortest wavelengths 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 indicating the lens imaging modulation degree at different spatial frequencies in each field of view of Example 4, with the horizontal axis representing spatial frequency (unit: lp / mm) and the vertical axis representing MTF value. As can be seen from the figure, the MTF value of this example is 0.5 or higher throughout the entire field of view, and the MTF curve drops smoothly and uniformly from the central field to the peripheral field within the range of (0 to 120) lp / mm, providing good imaging quality and good detail resolution at both low and high frequencies.

[0105] Table 5 shows the 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 illustrate some embodiments of the present invention, and although the descriptions are specific and detailed, they should not be understood as limiting the scope of the present invention. It should be noted that a person skilled in the art may make some modifications and improvements without departing from the spirit of the present invention, and all such modifications and improvements fall within the scope of the present invention. Therefore, the scope of the present invention is defined by the appended claims.

Claims

1. An optical lens consisting of six lenses, which are arranged in order from the object side to the image plane along the optical axis as follows: a first lens having a negative focal power, the object-side surface and the image-side surface of which are both concave; 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 and whose object-side surface and image-side surface are both convex; a fifth lens having a negative focal power and a concave surface on the object side and a convex surface on the image side; a sixth lens element having a convex object-side surface and a concave image-side surface, and having positive focal power; the fourth lens and the fifth lens are bonded 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 diameter HD1 of the object-side surface of the first lens corresponding to half the maximum angle of view of the optical lens and an aperture diameter D1 of the object-side surface of the first lens corresponding to the maximum angle of view of the optical lens satisfy 0.5<HD1 / D1<0.6 in the same cross section in which the optical axis is located.

2. 2. The optical lens according to claim 1, wherein the 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 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.

9. 2. 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, wherein an effective focal length f of the optical lens, a focal length f6 of the sixth lens, 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 of the sixth lens satisfy 2.8<f6 / f<3.9 and −3.0<(R11+R12) / (R11−R12)<−1.0, respectively.

Images