Optical lens

Abstract

The application provides an optical lens, which comprises six lenses in sequence along an optical axis from an object side to an imaging surface, and the six lenses comprise: a first lens with positive refractive power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; a second lens with negative refractive power, the object side surface of the second lens is a convex surface near the optical axis, and the image side surface of the second lens is a concave surface near the optical axis; a third lens with positive refractive power, the image side surface of the third lens is a convex surface; a fourth lens with positive refractive power, the object side surface and the image side surface of the fourth lens are both convex surfaces; a fifth lens with negative refractive power, the object side surface and the image side surface of the fifth lens are both concave surfaces; and a sixth lens with negative refractive power, the object side surface of the sixth lens is a concave surface near the optical axis, and the image side surface of the sixth lens is a convex surface near the optical axis; the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field of view angle satisfy 0.9 < f / IH < 1. The optical lens provided by the application has the advantages of large image surface, large aperture, long focus, large CRA and good imaging effect by reasonable configuration of the surface shape of each lens and reasonable matching of the refractive power.

Description

Technical Field

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

[0002] With the rapid development of drones, security, and automotive industries, the pursuit of imaging effects for their lenses has become more diversified. Currently, drones are developing rapidly, winning consumer favor with their unique high-altitude perspective and wide-angle shooting capabilities, leading to increasingly higher demands for their accompanying optical lenses. These lenses require not only high-definition image quality but also the ability to capture significant local details, ensuring that even from a high-altitude perspective, local details are rendered vividly, enabling the capture of close-up shots.

[0003] Therefore, it is necessary to develop an optical lens with a large image sensor, large aperture, long telephoto range, large CRA (Crystal Area Reduction), and good imaging performance to better meet market demands. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an optical lens with the advantage of excellent image quality.

[0005] This invention provides an optical lens comprising six lenses, arranged sequentially along the optical axis from the object side to the imaging plane:

[0006] The first lens with positive optical power has a convex object side and a concave image side.

[0007] The second lens with negative optical power has an object-side surface that is convex near the optical axis and an image-side surface that is concave near the optical axis.

[0008] The third lens with positive optical power has a convex image-side surface;

[0009] The fourth lens with positive optical power has convex surfaces on both its object side and image side.

[0010] The fifth lens with negative optical power has concave object-side and image-side surfaces;

[0011] The sixth lens with negative optical power has an object-side surface that is concave near the optical axis and an image-side surface that is convex near the optical axis.

[0012] The effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view satisfy: 0.9 <f / IH<1。

[0013] Further preferably, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view satisfy: 2 <TTL / IH<3。

[0014] More preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 2 < f1 / f < 8.

[0015] More preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -2 < f2 / f < -1.

[0016] More preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1 < f3 / f < 2.

[0017] More preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.7 < f4 / f < 1; the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -2 < f5 / f < -1.

[0018] More preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -7 < f6 / f < -3; the chief ray angle of incidence CRA of the optical lens satisfies: 25° < CRA < 38°.

[0019] More preferably, the effective focal length f of the optical lens and the combined focal length f45 of the fourth lens and the fifth lens satisfy: 1.5 < f45 / f < 2; the object-side curvature radius R41 of the fourth lens and the image-side curvature radius R52 of the fifth lens satisfy: 0.2 < R41 / R52 < 0.8.

[0020] More preferably, the focal length f1 of the first lens and the focal length f3 of the third lens satisfy: 1.5 < f1 / f3 < 4; the gap CT23 between the second lens and the third lens along the optical axis and the central thickness CT3 of the third lens along the optical axis satisfy: 1.5 < CT23 / CT3 < 2.5.

[0021] More preferably, the effective focal length f of the optical lens and the overall length TTL satisfy: 2 < TTL / f < 2.5.

[0022] More preferably, the effective focal length f of the optical lens, the radian value θ of the maximum field angle, and the true image height IH corresponding to the maximum field angle satisfy: -0.01 < (IH - f*θ) / (f*θ) < 0.02.

[0023] The optical lens provided by this invention employs six lenses with specific optical power. Through a specific surface shape combination and reasonable optical power distribution, the lens exhibits telephoto characteristics, enabling it to better present larger local details and make the image more focused and compact. It also achieves the large image plane characteristic of the lens, allowing it to present more image details. The optical lens also has a large aperture characteristic, effectively increasing the light throughput entering the lens and reducing the impact of noise generated in insufficient light on the image. This allows the lens to still have excellent imaging effects in dim environments, thus meeting the imaging needs of both bright and dark environments. Attached Figure Description

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0025] Figure 1 This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0026] Figure 2 This is the F-Tanθ distortion curve of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 3 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 4 This is an axial chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 5 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 6 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0031] Figure 7 This is the F-Tanθ distortion curve of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 8 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 9 This is an axial chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 10 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0035] Figure 11 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0036] Figure 12This is the F-Tanθ distortion curve of the optical lens in Embodiment 3 of the present invention.

[0037] Figure 13 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 14 This is an axial chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0039] Figure 15 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0040] Figure 16 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0041] Figure 17 This is the F-Tanθ distortion curve of the optical lens in Embodiment 4 of the present invention.

[0042] Figure 18 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0043] Figure 19 This is an axial chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0044] Figure 20 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0045] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0046] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0047] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0048] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0049] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0050] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0051] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0052] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0053] The optical lens of this invention comprises, in sequence along the optical axis from the object side to the imaging plane: a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, a sixth lens, and a filter.

[0054] In some embodiments, the first lens may have positive optical power, with its object-side surface being convex and its image-side surface being concave; the second lens may have negative optical power, with its object-side surface being convex near the optical axis and its image-side surface being concave near the optical axis; the third lens may have positive optical power, with its image-side surface being convex; the fourth lens may have positive optical power, with both its object-side and image-side surfaces being convex; the fifth lens may have negative optical power, with both its object-side and image-side surfaces being concave; and the sixth lens may have negative optical power, with its object-side surface being concave near the optical axis and its image-side surface being convex near the optical axis.

[0055] In some embodiments, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field angle satisfy: 0.9 < f / IH < 1. Meeting the above range can not only achieve the long focal length characteristics of the lens, presenting larger local details and making the picture more concentrated and compact, but also achieve the large image plane characteristics of the lens and realize high-pixel imaging of the lens.

[0056] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle satisfy: 2 < TTL / IH < 3. Meeting the above range is beneficial to limiting the overall length of the lens while better achieving large target plane imaging of the lens.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 2 < f1 / f < 8. Meeting the above range can make the first lens have an appropriate positive optical power, which is beneficial to the relatively gentle change of the refraction angle of incident light, avoiding excessive aberration caused by too strong refraction change, and at the same time helping more light to enter the rear optical system to achieve the large aperture performance of the lens.

[0058] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -2 < f2 / f < -1. Meeting the above range makes the second lens bear a large negative refractive power, which is beneficial to the smooth trend of light, transmitting as much marginal field light as possible to the rear-end system of the lens, and achieving the large aperture performance of the lens.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1 < f3 / f < 2. Meeting the above range is beneficial to better adjusting various chromatic aberrations of the system and improving resolution.

[0060] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.7 < f4 / f < 1. Meeting the above range makes the fourth lens bear a large positive refractive power, which is beneficial to the smooth trend of light, reducing the difficulty of correcting aberration, and improving the overall imaging quality.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -2 < f5 / f < -1. Meeting the above range makes the fifth lens bear an appropriate negative refractive power, which is beneficial to balancing the coma of the lens and improving the imaging quality of the optical lens.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -7 < f6 / f < -3. Having the sixth lens bear an appropriate negative refractive power is conducive to increasing the incident angle of light entering the image plane, enabling the lens to better match an imaging chip with a large CRA (chief ray angle of incidence) to achieve high-definition imaging; at the same time, it is conducive to increasing the imaging area of the lens and achieving large-format imaging of the lens. The chief ray angle of incidence CRA of the optical lens satisfies: 25° < CRA < 38°. Meeting the above range enables the lens to better match an imaging chip with a large CRA to achieve high-definition imaging and improve the adaptability of the optical lens to a large-CRA image sensor.

[0063] In some embodiments, the effective focal length f of the optical lens and the combined focal length f45 of the fourth and fifth lenses satisfy: 1.5 < f45 / f < 2; the object-side curvature radius R41 of the fourth lens and the image-side curvature radius R52 of the fifth lens satisfy: 0.2 < R41 / R52 < 0.8. Meeting the above range helps more light enter the system more smoothly, improve the relative illumination of the system, and at the same time, helps correct the chromatic aberration of the system and improve the overall imaging quality.

[0064] In some embodiments, the fourth and fifth lenses can be glued together to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0065] In some embodiments, the focal length f1 of the first lens and the focal length f3 of the third lens satisfy: 1.5 < f1 / f3 < 4. Meeting the above range is conducive to the smooth trend of light, reducing the difficulty of correcting aberration, and improving the overall imaging quality. The gap CT23 between the second and third lenses along the optical axis and the central thickness CT3 of the third lens along the optical axis satisfy: 1.5 < CT23 / CT3 < 2.5. Meeting the above range is conducive to the smooth trend of light, reducing the difficulty of correcting aberration, and improving the overall imaging quality.

[0066] In some embodiments, the effective focal length f of the optical lens and the overall optical length TTL satisfy: 2 < TTL / f < 2.5. Meeting the above range is conducive to restricting the overall length of the lens while better realizing the telephoto performance of the system.

[0067] In some embodiments, the effective focal length f of the optical lens, the radian value θ of the maximum field angle, and the true image height IH corresponding to the maximum field angle satisfy: -0.01 < (IH - f*θ) / (f*θ) < 0.02. Meeting the above range can increase the focal length of the lens while keeping the field angle and the size of the imaging plane unchanged, highlighting the imaging effect in the central area of the imaging plane of the lens.

[0068] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL satisfy: 0.2 < BFL / f < 0.3. Meeting the above range is beneficial to achieving the long focal length performance of the lens, while enabling the lens to have a large back focal length, which is conducive to the assembly of the module, reducing interference, and improving the production yield.

[0069] In some embodiments, the curvature radius R11 of the object side surface of the first lens and the curvature radius R12 of the image side surface of the second lens satisfy: 0.1 < R11 / R12 < 0.8. The curvature radius R21 of the object side surface of the second lens and the curvature radius R22 of the image side surface of the second lens satisfy: 2 < R21 / R22 < 5. Meeting the above range, by reasonably setting the surface types of the first lens and the second lens, the light entering the system can be effectively increased, achieving the large aperture performance of the lens and improving the imaging quality in bright and dark environments.

[0070] In some embodiments, the effective focal length f4 of the fourth lens and the effective focal length f5 of the fifth lens satisfy: -0.8 < f4 / f5 < -0.4. Meeting the above range is beneficial to the smooth transition of light, reducing the correction difficulty of chromatic aberration, and improving the overall imaging quality.

[0071] In some embodiments, the curvature radius R61 of the object side surface of the sixth lens and the curvature radius R62 of the image side surface of the sixth lens satisfy: 0.55 < R61 / R62 < 0.9. Meeting the above range, setting the sixth lens as a meniscus lens reduces the correction difficulty of aberration.

[0072] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -3.5 < f1 / f2 < -1.5. Meeting the above range, by reasonably setting the focal length relationship between the first lens and the second lens, the light can enter the subsequent system more smoothly, reducing the correction difficulty of aberration, and at the same time contributing to achieving the long focal length performance of the lens.

[0073] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value F# satisfy: 35° < FOV / F# < 50°. Meeting the above range is beneficial to expanding the field of view angle of the optical lens and increasing the aperture of the optical lens, achieving the characteristics of a large field of view angle and a large aperture.

[0074] As an implementation manner, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the second lens and the sixth lens adopt aspherical lenses, and the first lens, the third lens, the fourth lens, and the fifth lens adopt spherical lenses.

[0075] To achieve better optical performance, at least one aspherical lens is used in the lens, and the shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0076]

[0077] Where z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the quadratic surface coefficient, and A, B, C, D, E, F, and G are the second, fourth, sixth, eighth, tenth, twelfth, and fourteenth order surface coefficients, respectively.

[0078] The present invention will be further described below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different; for specific differences, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

[0079] Example 1

[0080] Please see Figure 1 The diagram shown is a schematic diagram of the structure of the optical lens provided in Embodiment 1 of the present invention. The optical lens includes, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a filter G1.

[0081] The first lens L1 has positive optical power, its object side S1 is convex, and its image side S2 is concave.

[0082] The second lens L2 has negative optical power, its object side S3 is convex near the optical axis, and its image side S4 is concave near the optical axis.

[0083] The third lens L3 has positive optical power, and its object side S5 and image side S6 are both convex surfaces.

[0084] Aperture ST;

[0085] The fourth lens L4 has positive optical power, and both its object-side surface S7 and image-side surface S8 are convex.

[0086] The fifth lens L5 has negative optical power, and both its object side S9 and image side S10 are concave.

[0087] The fourth lens L4 and the fifth lens L5 form a cemented lens group, that is, the image side of the fourth lens L4 and the object side of the fifth lens L5 are cemented surfaces.

[0088] The sixth lens L6 has negative optical power. Its object-side surface S11 is concave near the optical axis, and its image-side surface S12 is convex near the optical axis.

[0089] The object-side surface S13 and the image-side surface S14 of filter G1 are both planar.

[0090] The imaging plane S15 is a plane.

[0091] The second lens L2 and the sixth lens L6 are glass aspherical lenses, while the first lens L1, the third lens L3, the fourth lens L4, and the fifth lens L5 are all glass spherical lenses.

[0092] The relevant parameters of each lens in the optical lens of Example 1 are shown in Table 1-1.

[0093] Table 1-1

[0094]

[0095] The surface profile parameters of the aspherical lens in Example 1 are shown in Table 1-2.

[0096] Table 1-2

[0097] Face number K A B C D E F G S3 -1.35E+02 0.00E+00 -2.53E-04 -3.79E-06 2.12E-07 -3.92E-09 3.60E-11 -1.34E-13 S4 -1.31E+00 0.00E+00 -4.57E-04 2.78E-06 1.46E-07 -4.27E-09 5.29E-11 -2.48E-13 S11 -2.00E+00 0.00E+00 -2.13E-03 1.74E-04 -4.88E-06 6.61E-08 -3.59E-10 -1.50E-14 S12 -3.32E+00 0.00E+00 -2.53E-03 1.75E-04 -4.43E-06 6.04E-08 -4.18E-10 1.10E-12

[0098] In this embodiment, the F-Tanθ distortion curve, transverse chromatic aberration curve, axial chromatic aberration curve, and MTF curve of the optical lens are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown.

[0099] Figure 2 The F-Tanθ distortion curve of Example 1 is shown, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion value (unit: %), and the vertical axis represents the field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -10% to 0, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0100] Figure 3 The diagram shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.587 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±5 μm, indicating that the optical lens can excellently correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0101] Figure 4 The axial chromatic aberration curve of Example 1 is shown, which represents the chromatic aberration of each wavelength along the optical axis at the imaging plane. The horizontal axis represents the axial chromatic aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial chromatic aberration offset is controlled within ±0.07 mm, indicating that the optical lens can effectively correct the axial chromatic aberration.

[0102] Figure 5 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents the frequency range (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of this example is above 0.5 throughout the entire field of view. Within the range of 0–30 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0103] Example 2

[0104] Please see Figure 6 The figure shown is a schematic diagram of the optical lens provided in Embodiment 2 of the present invention. Compared with Embodiment 1, the main difference in this embodiment is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0105] The relevant parameters of each lens in the optical lens of Example 2 are shown in Table 2-1.

[0106] Table 2-1

[0107]

[0108]

[0109] The surface profile parameters of the aspherical lens in Example 2 are shown in Table 2-2.

[0110] Table 2-2

[0111] Face number K A B C D E F G S3 -1.35E+02 0.00E+00 -2.53E-04 -3.79E-06 2.11E-07 -3.92E-09 3.60E-11 -1.35E-13 S4 -1.30E+00 0.00E+00 -4.57E-04 2.75E-06 1.46E-07 -4.29E-09 5.26E-11 -2.45E-13 S11 -1.83E+01 0.00E+00 -1.55E-03 -1.36E-03 1.33E-03 -1.73E-04 -1.84E-07 7.61E-07 S12 -1.69E+00 0.00E+00 -7.87E-03 2.92E-03 -5.81E-04 1.23E-04 -5.80E-06 -7.74E-08

[0112] In this embodiment, the F-Tanθ distortion curve, transverse chromatic aberration curve, axial chromatic aberration curve, and MTF curve of the optical lens are respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0113] Figure 7The F-Tanθ distortion curves for Example 2 are shown, representing the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion value (unit: %), and the vertical axis represents the field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -10% to 0, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0114] Figure 8 The diagram shows the transverse chromatic aberration curves for Example 2, representing the chromatic aberration of each wavelength relative to the center wavelength (0.587 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the figure, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±5 μm, indicating that the optical lens can excellently correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0115] Figure 9 The axial chromatic aberration curve of Example 2 is shown, which represents the chromatic aberration of each wavelength along the optical axis at the imaging plane. The horizontal axis represents the axial chromatic aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial chromatic aberration offset is controlled within ±0.07 mm, indicating that the optical lens can effectively correct the axial chromatic aberration.

[0116] Figure 10 The MTF (Modulation Transfer Function) curve of Example 2 is shown, which represents the lens imaging modulation at different spatial frequencies in each field of view. The horizontal axis represents the frequency range (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of this example is above 0.4 throughout the entire field of view. Within the range of 0–30 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0117] Example 3

[0118] Please see Figure 11 The figure shown is a schematic diagram of the optical lens provided in Embodiment 3 of the present invention. Compared with Embodiment 1, the main difference in this embodiment is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0119] The relevant parameters of each lens in the optical lens of Example 3 are shown in Table 3-1.

[0120] Table 3-1

[0121]

[0122] The surface profile parameters of the aspherical lens in Example 3 are shown in Table 3-2.

[0123] Table 3-2

[0124] Face number K A B C D E F G S3 -1.76E+02 0.00E+00 -2.71E-04 -3.82E-06 2.12E-07 -3.91E-09 3.60E-11 -1.35E-13 S4 -1.24E+00 0.00E+00 -4.56E-04 2.70E-06 1.46E-07 -4.26E-09 5.29E-11 -2.50E-13 S11 -1.97E+00 0.00E+00 -2.09E-03 1.74E-04 -4.89E-06 6.56E-08 -3.66E-10 2.50E-13 S12 -3.14E+00 0.00E+00 -2.50E-03 1.76E-04 -4.44E-06 6.00E-08 -4.18E-10 1.18E-12

[0125] In this embodiment, the F-Tanθ distortion curve, transverse chromatic aberration curve, axial chromatic aberration curve, and MTF curve of the optical lens are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0126] Figure 12 The F-Tanθ distortion curve of Example 3 is shown, which represents the F-Tanθ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion value (unit: %), and the vertical axis represents the field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -10% to 0, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0127] Figure 13 The diagram shows the transverse chromatic aberration curves for Example 3, representing the chromatic aberration of each wavelength relative to the center wavelength (0.587 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the figure, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±4 μm, indicating that the optical lens can excellently correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0128] Figure 14 The axial chromatic aberration curve of Example 3 is shown, which represents the chromatic aberration of each wavelength along the optical axis at the imaging plane. The horizontal axis represents the axial chromatic aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial chromatic aberration offset is controlled within ±0.07 mm, indicating that the optical lens can effectively correct the axial chromatic aberration.

[0129] Figure 15 The MTF (Modulation Transfer Function) curve of Example 3 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents the frequency range (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of this example is above 0.4 throughout the entire field of view. Within the range of 0–30 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0130] Example 4

[0131] Please see Figure 16 The figure shows a schematic diagram of the optical lens provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the object side surface S5 of the third lens L3 is concave; the fourth lens L4 and the fifth lens L5 are spaced apart and are not cemented lenses; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0132] The relevant parameters of each lens in the optical lens of Example 4 are shown in Table 4-1.

[0133] Table 4-1

[0134]

[0135]

[0136] The surface profile parameters of the aspherical lens in Example 4 are shown in Table 4-2.

[0137] Table 4-2

[0138] Face number K A B C D E F G S3 -8.74E+01 0.00E+00 -2.70E-04 -1.66E-06 2.29E-07 -5.96E-09 7.15E-11 -3.39E-13 S4 -2.00E+00 0.00E+00 -4.67E-04 8.27E-06 5.61E-08 -4.82E-09 8.55E-11 -5.36E-13 S11 -1.05E+00 0.00E+00 -3.81E-04 1.85E-04 -7.40E-06 1.35E-07 -1.07E-09 1.58E-12 S12 -1.19E+00 0.00E+00 -1.42E-04 1.17E-04 -3.45E-06 4.12E-08 -8.75E-11 -1.33E-12

[0139] In this embodiment, the F-Tanθ distortion curve, transverse chromatic aberration curve, axial chromatic aberration curve, and MTF curve of the optical lens are respectively as follows: Figure 17 , Figure 18 , Figure 19 , Figure 20 As shown.

[0140] Figure 17 The F-Tanθ distortion curves for Example 4 are shown, representing the F-Tanθ distortion of different wavelengths of light at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion value (unit: %), and the vertical axis represents the field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens is controlled within -10% to 0, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0141] Figure 18 The diagram shows the transverse chromatic aberration curves for Example 4, representing the chromatic aberration of each wavelength relative to the center wavelength (0.587 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the figure, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±4 μm, indicating that the optical lens can excellently correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0142] Figure 19The axial chromatic aberration curve of Example 4 is shown, which represents the chromatic aberration on the optical axis at the imaging plane for each wavelength. The horizontal axis represents the axial chromatic aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. It can be seen from the figure that the offset of the axial chromatic aberration is controlled within ±0.05 mm, indicating that the optical lens can better correct the axial chromatic aberration.

[0143] Figure 20 The MTF (Modulation Transfer Function) curve of Example 4 is shown, which represents the modulation of the lens imaging at different spatial frequencies for each field of view. The horizontal axis represents the frequency range (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF value of this embodiment is above 0.55 within the entire field of view. In the range of 0 - 30 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0144] Please refer to Table 5 for the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the aperture value F#, the true image height IH corresponding to the maximum field of view angle, the chief ray angle of incidence CRA, and the maximum field of view angle FOV, as well as the numerical values corresponding to each conditional formula in each embodiment.

[0145] Table 5

[0146]

[0147]

[0148] Combining the above embodiments, the optical lens provided by the present invention, through the reasonable configuration of each lens surface type and the reasonable combination of the optical power, enables the lens to have a long focal length characteristic (16 mm < f < 20 mm), can better present larger local details, make the picture more concentrated and compact; can also achieve the large image plane characteristic of the lens (16 mm < IH < 20 mm), and can present more picture details; the optical lens also has a large aperture characteristic (1.3 < F# < 1.6), effectively increasing the light flux entering the lens, reducing the influence of noise generated when the light is insufficient on the imaging picture, and enabling the lens to still have excellent imaging effects in a dim environment, so as to meet the imaging requirements in both bright and dim environments. The optical lens also has the advantage of a large CRA, can better match the imaging chip with a large CRA to achieve high-definition imaging, and improve the adaptability of the optical lens to the image sensor with a large CRA.

[0149] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0150] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens comprising six lenses, characterized in that, It successively includes from the object side to the imaging surface along the optical axis: A first lens with positive optical power, whose object side is convex and whose image side is concave; A second lens with negative optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; A third lens with positive optical power, whose image side is convex; A fourth lens with positive optical power, whose object side and image side are both convex; A fifth lens with negative optical power, whose object side and image side are both concave; A sixth lens with negative optical power, whose object side is concave near the optical axis and whose image side is convex near the optical axis; The effective focal length f of the optical lens and the true image height IH corresponding to the maximum field angle satisfy: 0.9 < f / IH < 1; The effective focal length f of the optical lens, the radian value θ of the maximum field angle and the true image height IH corresponding to the maximum field angle satisfy: -0.01 < (IH - f*θ) / (f*θ) ≤ 0.012; The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -7 < f6 / f < -3; 2. The optical lens according to claim 1, characterized in that, The overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle satisfy: 2 < TTL / IH < 3; 3. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 2 < f1 / f < 8; 4. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -2 < f2 / f ≤ -1.405; 5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.309 ≤ f3 / f < 2; 6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.7 < f4 / f < 1; The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -2 < f5 / f < -1; 7. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -7 < f6 / f ≤ -3.388; The chief ray angle of incidence CRA of the optical lens satisfies: 25° < CRA < 38°; 8. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the combined focal length f45 of the fourth lens and the fifth lens satisfy: 1.5 < f45 / f ≤ 1.856; The curvature radius R41 of the object side of the fourth lens and the curvature radius R52 of the image side of the fifth lens satisfy: 0.2 < R41 / R52 < 0.8; 9. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the focal length f3 of the third lens satisfy: 1.5 < f1 / f3 < 4; The gap CT23 between the second lens and the third lens along the optical axis and the central thickness CT3 of the third lens along the optical axis satisfy: 1.5 < CT23 / CT3 < 2.5; 10. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the overall optical length TTL satisfy: 2 < TTL / f < 2.5; 11. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens, the radian value θ of the maximum field angle and the true image height IH corresponding to the maximum field angle satisfy: -0.006 ≤ (IH - f*θ) / (f*θ) ≤ 0.012; The effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view satisfy the following condition: 0.944≤f / IH≤0.961.

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