Optical lens

Abstract

The application provides an optical lens, which comprises, along an optical axis from an object side to an imaging surface, a front lens group with negative focal power and a rear lens group with positive focal power; the front lens group comprises a first lens with negative focal power, a convex object side surface and a concave image side surface; a second lens with negative focal power, a concave object side surface near the optical axis and a concave image side surface; and a third lens with negative focal power, a concave object side surface and a convex image side surface; the rear lens group comprises a fourth lens with positive focal power, a convex object side surface and a convex image side surface; a fifth lens with negative focal power, a concave object side surface and a concave image side surface; a sixth lens with positive focal power, a convex object side surface and a convex image side surface; and a seventh lens with positive focal power, a convex object side surface near the optical axis and a concave image side surface; the optical lens has one or more advantages of super wide angle, super large aperture, miniaturization and the like.

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 continuous development of information technologies such as computer network technology and intelligent control technology, the concept of intelligence has gradually permeated the imaging equipment industry, leading to the rapid development of intelligent imaging equipment represented by action cameras, aerial drones, and panoramic cameras. This drone obstacle avoidance lens is a hybrid glass-plastic lens that combines the advantages of both glass and plastic lenses. It effectively corrects system chromatic aberration, improves the light intake and image clarity of the optical system, and is of great significance in machine vision, pipeline inspection, and panoramic monitoring. It also has broad application prospects in aviation, defense, and civilian fields. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide an optical lens that has one or more advantages such as ultra-wide angle, large aperture, and miniaturization.

[0004] The present invention provides an optical lens composed of seven lenses, which, along the optical axis from the object side to the imaging plane, include: a front lens group with negative optical power and a rear lens group with positive optical power.

[0005] The front lens group, along the optical axis from the object side to the imaging plane, includes, in sequence:

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

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

[0008] A third lens with negative optical power has a concave object side and a convex image side.

[0009] The rear lens group, along the optical axis from the object side to the imaging plane, includes, in sequence:

[0010] The fourth lens with positive optical power has a convex object-side surface and a convex image-side surface.

[0011] The fifth lens with negative optical power has a concave object side and a concave image side.

[0012] The sixth lens with positive optical power has a convex object-side surface and a convex image-side surface.

[0013] The seventh lens with positive optical power has an object-side surface that is convex near the optical axis and an image-side surface that is concave.

[0014] Among them, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 160° < FOV / Fno < 165°.

[0015] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -5.5 < f1 / f < -3.5; the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: -0.35 < f1 / f7 < -0.05.

[0016] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -6 < f2 / f < -4.5; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -9 < R3 / f < -4; the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 4.5 < R4 / f < 6.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -15 < f3 / f < -8; the curvature radius R5 of the object side surface of the third lens, the curvature radius R6 of the image side surface of the third lens and the central thickness CT3 of the third lens satisfy: 0.9 < (R5 - CT3) / R6 < 1.

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.5 < f4 / f < 2.5.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -10 < f5 / f < -3.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 4 < f6 / f < 6.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 10 < f7 / f < 65; the curvature radius R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1.2 < R14 / f < 6.

[0022] Further preferably, the effective focal length f of the optical lens and the combined focal length fa of the front lens group satisfy: -1.9 < fa / f < -1.6; the effective focal length f of the optical lens and the combined focal length fb of the rear lens group satisfy: 1.8 < fb / f < 2.4.

[0023] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 10.2 < TTL / f < 10.5; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.75 < TTL / IH < 2.9.

[0024] Further preferably, the effective focal length f of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the radian value θ of the maximum half-field angle of the optical lens satisfy: 0.97 < (IH / 2) / (f×θ) < 1.03.

[0025] Compared with the prior art, the optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can effectively improve the aberration of the optical lens, improve the imaging quality of the optical lens, and at the same time can achieve ultra-wide-angle imaging of the optical lens, recognize a larger range of objects and reasonably avoid them; it can make the optical lens have a large aperture performance. When the optical lens forms an image in a relatively dim environment, it can reduce the noise impact caused by too weak light, thereby improving the imaging quality; at the same time, it also makes the optical lens have one or more advantages such as miniaturization, small distortion, and high imaging quality. Description of the Drawings

[0026] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, where:

[0027] Figure 1 It is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 2 It is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 3 It is an f-theta distortion curve diagram of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 4 It is a vertical chromatic aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 5 It is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 6 It is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 7 It is an f-theta distortion curve diagram of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 8 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0035] Figure 9 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0036] Figure 10 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0037] Figure 11 This is an f-theta distortion curve of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 12 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0039] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] The optical lens provided in this embodiment of the invention consists of seven lenses, which are arranged sequentially along the optical axis from the object side to the imaging plane: a front lens group with negative optical power and a rear lens group with positive optical power.

[0048] Specifically, the front lens group comprises, along the optical axis from the object side to the imaging plane, a first lens, a second lens, and a third lens. The first lens may have negative optical power, with a convex object side and a concave image side; the second lens may have negative optical power, with a concave object side near the optical axis and a concave image side; and the third lens may have negative optical power, with a concave object side and a convex image side.

[0049] Specifically, the rear lens group includes, along the optical axis from the object side to the imaging plane, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. 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; the sixth lens may have positive optical power, with both its object-side and image-side surfaces being convex; and the seventh lens may have positive optical power, with its object-side surface being convex near the optical axis and its image-side surface being concave.

[0050] In some implementations, the fifth and sixth lenses can be combined to form a cemented lens, which can better correct the overall chromatic aberration of the system and improve the overall imaging quality.

[0051] In some embodiments, the optical lens may further include an aperture, which may be located between the third lens and the fourth lens, that is, between the front lens group and the rear lens group. It can be understood that the aperture is used to limit the amount of incident light to change the brightness of the image. When the aperture is located between the third lens and the fourth lens, it is convenient for correcting the aperture aberration.

[0052] In some embodiments, the optical lens may further include a filter and a protective glass, which may be sequentially arranged along the optical axis between the seventh lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging. The protective glass plays a role in protecting the optical lens, preventing the photosensitive chip from being damaged, and can improve the anti-shock ability of the optical lens, while having almost no impact on the imaging quality of the optical lens.

[0053] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 160° < FOV / Fno < 165°. Meeting the above conditions is beneficial to expanding the field of view angle of the optical lens and increasing the aperture of the optical lens, realizing the characteristics of ultra-wide angle and large aperture of the lens. The realization of the ultra-wide angle characteristic is beneficial for the optical lens to obtain more scene information, meet the needs of large-range detection and achieve reasonable avoidance. The realization of the large aperture characteristic is beneficial to improving the problem that the relative brightness of the edge field of view drops rapidly due to the wide angle, and thus is also beneficial to obtaining more scene information. When the optical lens images in a relatively dim environment, it can reduce the noise impact caused by too weak light, thereby improving the imaging quality.

[0054] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -5.5 < f1 / f < -3.5; the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: -0.35 < f1 / f < -0.05. Meeting the above conditions, by reasonably setting the negative refractive power of the first lens and the positive refractive power of the seventh lens, it is beneficial to reduce the inclination angle of the incident light, so as to collect the edge field of view light into the rear optical lens as much as possible, and achieve large-angle light collection to a large extent; at the same time, it can effectively increase the height of the light entering the imaging surface and realize large image plane imaging of the lens.

[0055] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -6 < f2 / f < -4.5; the radius of curvature R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -9 < R3 / f < -4; the radius of curvature R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 4.5 < R4 / f < 6. Meeting the above conditions, by reasonably setting the negative refractive power and surface shape of the second lens, the negative optical power at the front end of the lens can be shared, which is beneficial to reducing the excessive light deflection caused by the overly concentrated optical power of the first lens and reducing the difficulty of chromatic aberration correction of the optical lens.

[0056] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: -1.8 < R3 / R4 < -0.7; meeting the above conditions, by reasonably setting the double concave surface shape of the second lens, it is beneficial to receive large-angle incident light and control the incident light to enter the optical system more gently, thereby reducing the tolerance sensitivity of the optical system.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -15 < f3 / f < -8; meeting the above conditions, the third lens can have appropriate negative refractive power and surface shape, which can further reduce the light deflection angle, make the light trend transition smoothly, and improve the imaging quality of the optical lens.

[0058] In some embodiments, the radius of curvature R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: -4 < R6 / f < -2.5; meeting the above conditions, the difficulty of edge field distortion correction can be effectively reduced, ensuring that the lens has a small distortion while achieving a large field angle, improving the overall imaging quality, and at the same time reducing the system sensitivity and improving the manufacturing yield.

[0059] In some embodiments, the radius of curvature R5 of the object side surface of the third lens, the radius of curvature R6 of the image side surface of the third lens and the central thickness CT3 of the third lens satisfy: 0.9 < (R5 - CT3) / R6 < 1. Meeting the above conditions, by setting the third lens to a meniscus shape close to a concentric circle, the deflection angle of light in the third lens can be alleviated, and at the same time, the chromatic aberration and distortion generated by the first two lenses can be effectively balanced, improving the overall imaging quality.

[0060] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.5 < f4 / f < 2.5. Meeting the above conditions, by setting the fourth lens to have a large positive refractive power, the large-range light entering the system can be effectively converged, and at the same time, the off-axis aberration brought by the negative lens group in front of the diaphragm can be corrected, improving the imaging quality of the optical lens.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -10 < f5 / f < -3. Meeting the above conditions can endow the fifth lens with appropriate negative refractive power, which is beneficial to increasing the imaging area of the optical lens, optimizing the chromatic aberration of the optical 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: 4 < f6 / f < 6. Meeting the above conditions can endow the sixth lens with appropriate positive refractive power, which is beneficial to improving the light converging ability of the optical lens, balancing various aberrations generated by the optical lens, and improving the imaging quality of the optical lens.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 10 < f7 / f < 65; meeting the above conditions can endow the seventh lens with appropriate positive refractive power, which is beneficial to suppressing the angle of the marginal field incident on the imaging surface, effectively transmitting more light beams to the imaging surface, and improving the imaging quality of the optical lens.

[0064] In some embodiments, the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1.2 < R14 / f < 6. Meeting the above conditions, by reasonably controlling the radius of curvature of the image side surface of the seventh lens, the incident angle of light on the image surface can be reduced, and the illuminance of the marginal field can be enhanced.

[0065] In some embodiments, the effective focal length f of the optical lens and the combined focal length fa of the front lens group satisfy: -1.9 < fa / f < -1.6; meeting the above conditions, by setting the front lens group before the aperture to have a large negative refractive power, the object surface light within a wide field of view can be collected as much as possible, which is beneficial to achieving ultra-wide-angle imaging of the optical lens, and better correcting the edge distortion of the lens, and improving the imaging quality of the edge.

[0066] In some embodiments, the effective focal length f of the optical lens and the combined focal length fb of the rear lens group satisfy: 1.8 < fb / f < 2.4. Meeting the above conditions, by setting the rear lens group after the aperture to have a large positive refractive power, it is beneficial to balancing the distortion and astigmatism generated by the front lens of the optical lens, and improving the imaging quality of the optical lens.

[0067] In some embodiments, the effective focal length f of the optical lens and the combined focal length fa of the front lens group satisfy: -1 < fa / fb < -0.6; by satisfying the above conditions, through reasonable setting of the focal length relationship between the front and rear lens groups of the aperture stop, the deflection angles of the light rays before and after the aperture stop can be reduced, which helps the smooth transition of the light rays, expands the field angle of the optical lens, reduces the difficulty of correcting distortion and chromatic aberration of the rear lens, and improves the image quality of the optical lens.

[0068] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 10.2 < TTL / f < 10.5; by satisfying the above conditions, the length of the lens can be effectively limited, which is beneficial to the miniaturization of the optical lens.

[0069] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.75 < TTL / IH < 2.9. By satisfying the above conditions, the miniaturization of the lens can be better achieved. At the same time, when the overall length of the lens is the same, it has a larger image plane, which can match a larger-sized imaging chip to achieve high-definition imaging.

[0070] In some embodiments, the overall optical length TTL of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.038 mm / ° < TTL / FOV < 0.042 mm / °. By satisfying the above conditions, the requirements of ultra-wide-angle imaging and miniaturization of the optical lens can be effectively balanced. Ultra-wide-angle imaging can identify a larger range of objects and can achieve reasonable avoidance. Miniaturization can make its structure compact, which is beneficial to the installation of the whole machine and better meets the use requirements of miniaturized electronic devices.

[0071] In some embodiments, the effective focal length f of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the radian value θ of the maximum half field angle of the optical lens satisfy: 0.97 < (IH / 2) / (f×θ) < 1.03. By satisfying the above conditions, it shows that the F-theta distortion of the optical lens is well controlled, and the resolution of the optical lens is improved.

[0072] In some embodiments, the effective semi-aperture DM11 of the object side of the first lens and the effective semi-aperture DM12 of the image side of the first lens satisfy: 1.8 < DM11 / DM12 < 2.4; by satisfying the above conditions, by effectively controlling the apertures of the object side and the image side of the first lens, while increasing the field angle, the front aperture of the optical lens is controlled.

[0073] In some embodiments, the effective semi-aperture DM11 of the object side surface of the first lens and the effective semi-aperture DM12 of the image side surface of the seventh lens satisfy: 2.55 < DM11 / DM72 < 3; Meeting the above conditions can make the lens have a larger entrance aperture. While ensuring that as much light as possible enters the system, it increases the area of light entering the imaging surface, which is beneficial to achieving the balance of a large image surface and a large aperture of the lens.

[0074] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 1 < BFL / f < 1.8. Meeting the above conditions can make the lens have an appropriate optical back focal length, which is beneficial to reducing the interference between the lens and the imaging chip, ensuring the compatibility between the lens and the fuselage, and making the structure of the lens more compact.

[0075] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4.5 < IH / EPD < 5. Meeting the above conditions can effectively increase the width of the incident light beam at different field angles, improve the brightness of the optical lens at the image plane to avoid the generation of vignetting, and at the same time increase the imaging area of the optical lens to achieve large target surface imaging of the lens.

[0076] In some embodiments, the optical lens satisfies the conditional formula: 8mm < TTL < 8.8mm, 0.75mm < f < 0.85mm, 205° < FOV < 215°, 2.5mm < IH < 3.3mm, 1.2 < Fno < 1.4, where TTL represents the overall optical length of the optical lens, f represents the effective focal length of the optical lens, FOV represents the maximum field angle of the optical lens, IH represents the true image height corresponding to the maximum field angle of the optical lens, and Fno represents the aperture value of the optical lens. Meeting the above conditions indicates that the optical lens has a large field angle, can identify a larger range of objects and reasonably avoid them; has a large aperture value, and even when imaging in a relatively dim environment, it can reduce the noise impact caused by too weak light, thereby improving the imaging quality; at the same time, it also has a smaller overall length, the structure is relatively compact, and it can better meet the usage requirements of small electronic devices.

[0077] In some embodiments, the seven lenses in the optical lens can all adopt plastic lenses or adopt a structure with a combination of glass and plastic materials. Preferably, the optical lens of the present invention adopts a lens structure with a combination of seven glass and plastic materials, which can improve the thermal stability performance. Specifically, the first lens and the third lens can adopt glass lenses, and the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are all plastic lenses; adopting a glass-plastic hybrid structure can effectively reduce costs, correct aberrations, reduce the volume, and provide an optical lens product with higher cost performance.

[0078] In some embodiments, the first, second, third, fourth, fifth, sixth, and seventh lenses can be spherical or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce aberrations in the optical system, thereby reducing the number of lenses and their size, and better achieving lens miniaturization. More specifically, in the optical lens provided by this invention, the first and third lenses are spherical lenses, while the second, fourth, fifth, sixth, and seventh lenses can be aspherical lenses.

[0079] In various embodiments of the present invention, when an aspherical lens is used, the shapes of each aspherical surface of the optical lens satisfy the following equations:

[0080]

[0081] 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 B, C, D, E, F, G, and H are the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order surface coefficients, respectively.

[0082] 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.

[0083] Example 1

[0084] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane S17, the following components in sequence: a front lens group with negative optical power, an aperture stop ST, a rear lens group with positive optical power, and a filter G1.

[0085] The front lens group consists of, along the optical axis from the object side to the imaging plane, the following elements in sequence: first lens L1, second lens L2, and third lens L3.

[0086] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0087] The second lens L2 has negative optical power, its object side S3 is concave near the optical axis, and its image side S4 is concave.

[0088] The third lens L3 has negative optical power, its object side S5 is concave, and its image side S6 is convex.

[0089] The rear lens group, along the optical axis from the object side to the imaging plane, includes the following lenses in sequence: fourth lens L4, fifth lens L5, sixth lens L6, and seventh lens L7.

[0090] Among them, the fourth lens L4 has positive optical power, its object side S7 is convex, and its image side S8 is convex.

[0091] The fifth lens L5 has negative optical power, its object side S9 is concave, and its image side S10 is concave.

[0092] The sixth lens L6 has positive optical power, its object side S11 is convex, and its image side S12 is convex; the fifth lens L5 and the sixth lens L6 form a cemented lens;

[0093] The seventh lens L7 has positive optical power, its object side S13 is convex near the optical axis, and its image side S14 is concave.

[0094] The object-side surface S15 and the image-side surface S16 of filter G1 are both planar.

[0095] The imaging plane S17 is a plane.

[0096] The first lens L1 and the third lens L3 are glass spherical lenses; the second lens L2, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all plastic aspherical lenses.

[0097] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0098] Table 1-1

[0099]

[0100] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0101] Table 1-2

[0102]

[0103] In this embodiment, the field curvature curve, f-theta distortion curve, and transverse chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 As shown.

[0104] Figure 2The field curvature curve of the optical lens 100 in this embodiment is shown, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.1 mm, indicating that the optical lens 100 can correct the field curvature well.

[0105] Figure 3 The f-theta distortion curve of the optical lens 100 in this embodiment is shown, which represents the distortion at different field-of-view angles on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the field-of-view angle (unit: °). As can be seen from the figure, the f-theta distortion value of the lens is controlled within ±2.5%, indicating that the optical lens 100 can correct distortion well.

[0106] Figure 4 The diagram shows the transverse chromatic aberration curve of the optical lens 100 in this embodiment. It represents the chromatic aberration of each wavelength relative to the center wavelength (0.555 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 ±13 μm, indicating that the optical lens 100 can effectively correct chromatic aberration.

[0107] Example 2

[0108] Please see Figure 5 The figure shown is a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature of each lens surface, lens thickness, and material selection are different.

[0109] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0110] Table 2-1

[0111]

[0112]

[0113] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0114] Table 2-2

[0115]

[0116] In this embodiment, the field curvature curve, f-theta distortion curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 6, Figure 7 , Figure 8 As shown.

[0117] from Figure 6 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.2mm, indicating that the optical lens 200 can effectively correct the field curvature.

[0118] from Figure 7 As can be seen, the f-theta distortion value is controlled within ±4%, indicating that the optical lens 200 can correct distortion well.

[0119] from Figure 8 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±12.5μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0120] Example 3

[0121] Please see Figure 9 The figure shown is a structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature of each lens surface, lens thickness, and material selection are different.

[0122] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0123] Table 3-1

[0124]

[0125] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0126] Table 3-2

[0127]

[0128] In this embodiment, the field curvature curve, f-theta distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 300 are respectively as follows: Figure 10 , Figure 11 , Figure 12 As shown.

[0129] from Figure 10 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.075mm, indicating that the optical lens 300 can effectively correct the field curvature.

[0130] from Figure 11 As can be seen, the f-theta distortion value is controlled within ±2%, indicating that the optical lens 300 can correct distortion well.

[0131] It can be seen from Figure 12 that the vertical chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±12 μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0132] Please refer to Table 4 for the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the overall optical length TTL, the aperture value Fno, the true image height IH corresponding to the maximum field angle, the chief ray angle of incidence CRA at the maximum image height, the maximum field angle FOV, and the values corresponding to each conditional formula in each embodiment.

[0133] Table 4

[0134]

[0135]

[0136] In summary of the above embodiments, the optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can effectively improve the aberration of the optical lens, improve the imaging quality of the optical lens, and at the same time can achieve ultra-wide-angle imaging of the optical lens (FOV can reach 210°), enabling shooting in a large range, being able to identify objects in a larger range and reasonably avoid them, and the lens has a small distortion (f-theta distortion < 4%); it can endow the optical lens with a large aperture performance (Fno can reach 1.3). When the optical lens forms an image in a relatively dim environment, it can reduce the noise impact caused by too weak light, thereby improving the imaging quality; at the same time, it also makes the optical lens have a small overall optical length (8 mm < TTL < 8.8 mm), with a compact structure, which is conducive to the installation of the whole machine and better adapts to the usage requirements of miniaturized electronic devices.

[0137] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0138] 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 seven lenses, characterized in that, It sequentially includes, from the object side to the imaging surface along the optical axis: a front lens group with a negative optical power and a rear lens group with a positive optical power; The front lens group sequentially includes, from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side surface is convex and whose image side surface is concave; A second lens with a negative optical power, whose object side surface is concave near the optical axis and whose image side surface is concave; A third lens with a negative optical power, whose object side surface is concave and whose image side surface is convex; The rear lens group sequentially includes, from the object side to the imaging surface along the optical axis: A fourth lens with a positive optical power, whose object side surface is convex and whose image side surface is convex; A fifth lens with a negative optical power, whose object side surface is concave and whose image side surface is concave; A sixth lens with a positive optical power, whose object side surface is convex and whose image side surface is convex; A seventh lens with a positive optical power, whose object side surface is convex near the optical axis and whose image side surface is concave; Wherein, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 160° < FOV / Fno < 165°.

2. 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: -5.5 < f1 / f < -3.5; the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: -0.35 < f1 / f7 < -0.

05.

3. 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: -6 < f2 / f < -4.5; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -9 < R3 / f < -4; the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 4.5 < R4 / f < 6.

4. 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: -15 < f3 / f < -8; the curvature radius R5 of the object side surface of the third lens, the curvature radius R6 of the image side surface of the third lens and the central thickness CT3 of the third lens satisfy: 0.9 < (R5 - CT3) / R6 < 1.

5. 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: 1.5 < f4 / f < 2.

5.

6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -10 < f5 / f < -3.

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: 4 < f6 / f < 6.

8. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 10 < f7 / f < 65; the curvature radius R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1.2 < R14 / f < 6.

9. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the combined focal length fa of the front lens group satisfy: -1.9 < fa / f < -1.6; the effective focal length f of the optical lens and the combined focal length fb of the rear lens group satisfy: 1.8 < fb / f < 2.

4.

10. The optical lens according to claim 1, characterized in that, The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 10.2 < TTL / f < 10.5; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of view of the optical lens satisfy: 2.75 < TTL / IH < 2.

9.

11. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens, the true image height IH corresponding to the maximum field angle of view of the optical lens, and the radian value θ of the maximum half-field angle of view of the optical lens satisfy: 0.97 < (IH / 2) / (f×θ) < 1.03.

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