Optical lens

Abstract

This invention provides an optical lens comprising seven lenses, arranged sequentially along the optical axis from the object side to the image plane: a first lens with negative optical power, its object side being convex and its image side being concave; a second lens with positive optical power, its object side being convex and its image side being concave; a third lens with negative optical power, its object side being concave and its image side being convex; a fourth lens with positive optical power, its object side being concave and its image side being convex; a fifth lens with positive optical power, its object side being convex and its image side being concave; a sixth lens with negative optical power, its object side being convex and its image side being concave; and a seventh lens with positive optical power, its object side being convex and its image side being concave. The optical lens provided by this invention can improve the imaging quality of an optical lens, reduce aberrations, and enhance the image quality of the optical lens, giving the lens one or more advantages such as a large image plane, a large aperture, and high image quality.

Description

Technical Field

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

[0002] As people's demands for driving experience continue to increase, automotive optical lenses are being used more and more in intelligent driving, and the status of automotive optical lenses in the automotive industry is constantly rising.

[0003] Advanced Driver Assistance Systems (ADAS) play a crucial role in intelligent driving. They use various lenses and sensors to collect environmental information to ensure driver safety. Existing ADAS lenses not only require a slim and compact design with high pixel count and high resolution, but also need to produce clear images in low-light conditions. Therefore, it is necessary to develop an optical lens with excellent imaging performance. 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] The technical solution adopted in this invention is as follows:

[0006] An optical lens comprises seven lenses, arranged sequentially along the optical axis from the object side to the imaging plane:

[0007] The first lens with negative optical power has a convex object side and a concave image side.

[0008] A second lens with positive optical power has a convex object-side surface and a concave image-side surface;

[0009] A third lens with negative optical power has a concave object side and a convex image side.

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

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

[0012] The sixth lens with negative optical power has a convex object side and a concave image side.

[0013] The seventh lens with positive optical power has a convex object-side surface and a concave image-side surface.

[0014] Wherein, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -1.8 <f3 / f4<-1.6;

[0015] The focal length f3 of the third lens and the focal length f5 of the fifth lens satisfy: -2.5 < f3 / f5 < -2.2.

[0016] Further preferably, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.4 < TTL / f < 5.6; 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: 4.7 < TTL / IH < 4.9.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.4 < f1 / f < -2.2; the radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: 2.6 < R1 / f < 3; the radius of curvature R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.8 < R2 / f < 0.9.

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 4.9 < f2 / f < 5.4; 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: 2.2 < R3 / f < 2.5; 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: 3.4 < R4 / f < 3.8.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -4.3 < f3 / f < -4; the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.4 < f7 / f < 1.5.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.3 < f4 / f < 2.5; the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -44 < R7 / f < -42; the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -1.5 < R8 / f < -1.4.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.7 < f5 / f < 1.9; the radius of curvature R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 1 < R9 / f < 1.1; the radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 42 < R10 / f < 4-4.

[0022] It should be noted that there seems to be a small error in the original text where "42 < R10 / f < 4-4" should probably be "42 < R10 / f < 44". The translation is based on the original text as provided.Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.4 < f6 / f < -1.2; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: 42 < R11 / f < 44; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: 0.8 < R12 / f < 1.

[0023] Further preferably, the combined focal length f56 of the fifth lens and the sixth lens and the focal length f of the optical lens satisfy: -51 < f56 / f < -28; the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -1.9 < f123 / f4567 < -1.7.

[0024] Further preferably, the object-side curvature radius R7 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy: 0.9 < (R7 - R8) / (R7 + R8) < 1; the object-side curvature radius R9 of the fifth lens and the image-side curvature radius R10 of the fifth lens satisfy: -1 < (R9 - R10) / (R9 + R10) < -0.9.

[0025] 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 improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, enabling the lens to have one or more advantages such as a large target surface, a large aperture, and high imaging quality. BRIEF 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 description of the embodiments in conjunction with the following drawings, where:

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

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

[0029] Figure 3 is an F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 4 is an axial aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 5 is a lateral chromatic aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0032] Figure 6 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0033] Figure 7 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0034] Figure 8 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0035] Figure 9 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.

[0036] Figure 10 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0037] Figure 11 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0038] Figure 12 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0039] Figure 13 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0040] Figure 14 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0041] Figure 15 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.

[0042] Figure 16 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0043] Figure 17 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0044] Figure 18 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0045] Figure 19 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0046] Figure 20 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0047] Figure 21 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 4 of the present invention.

[0048] Figure 22 This is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0049] Figure 23 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0050] Figure 24 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0051] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] The optical lens provided in this embodiment of the invention has a total of seven lenses, which are arranged sequentially from the object side to the imaging plane along the optical axis as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

[0060] In some embodiments, the first lens may have negative optical power, with a convex object-side surface and a concave image-side surface. The second lens may have positive optical power, with a convex object-side surface and a concave image-side surface. The third lens may have negative optical power, with a concave object-side surface and a convex image-side surface. The fourth lens may have positive optical power, with a concave object-side surface and a convex image-side surface. The fifth lens may have positive optical power, with a convex object-side surface and a concave image-side surface. The sixth lens may have negative optical power, with a convex object-side surface and a concave image-side surface. The seventh lens may have positive optical power, with a convex object-side surface and a concave image-side surface.

[0061] In some embodiments, the optical lens may also include an aperture stop, which may be located between the third and fourth lenses. It is understood that the aperture stop is used to limit the amount of light entering the lens to change the brightness of the image. When the aperture stop is located between the third and fourth lenses, it facilitates the correction of aperture aberrations.

[0062] In some embodiments, the optical lens may further include a filter and a protective glass, which are sequentially disposed between the seventh lens and the imaging surface along the optical axis. 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 impact resistance and scratch resistance of the optical lens, while having almost no impact on the imaging quality of the optical lens.

[0063] In some embodiments, the fifth lens and the sixth lens may be glued together to form a glued 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.

[0064] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -1.8 < f3 / f4 < -1.6; the focal length f3 of the third lens and the focal length f5 of the fifth lens satisfy: -2.5 < f3 / f5 < -2.2. Satisfying the above ranges, by reasonably setting the focal length relationship of the third, fourth, and fifth lenses, it is beneficial to the smooth transition of light, while correcting various aberrations of the optical lens and improving the imaging quality of the optical lens. More specifically, -1.75 < f3 / f4 < -1.68; -2.41 < f3 / f5 < -2.26.

[0065] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.4 < TTL / f < 5.6. Satisfying the above range can effectively limit the length of the lens, which is beneficial to the miniaturization of the optical lens. More specifically, 5.4 < TTL / f < 5.58.

[0066] 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: 4.7 < TTL / IH < 4.9. Satisfying the above range ensures that the lens has a larger image surface under the same overall length, can match a larger size imaging chip to achieve high-definition imaging, and better achieves the balance between the small overall length and the large image surface of the lens. More specifically, 4.72 < TTL / IH < 4.88.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.4 < f1 / f < -2.2; the radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: 2.6 < R1 / f < 3; the radius of curvature R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.8 < R2 / f < 0.9; the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 0.5 < (R1 - R2) / (R1 + R2) < 0.6. Meeting the above ranges, by setting the first lens to have a negative refractive power and a suitable surface shape, it is beneficial for the first lens to accommodate a larger angle of light rays and collect as much light as possible to enter the rear optical system, increasing the light flux while achieving a large field of view. More specifically, -2.34 < f1 / f < -2.21; 2.68 < R1 / f < 2.94; 0.84 < R2 / f < 0.89; 0.51 < (R1 - R2) / (R1 + R2) < 0.55.

[0068] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 4.9 < f2 / f < 5.4; 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: 2.2 < R3 / f < 2.5; 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: 3.4 < R4 / f < 3.8. Meeting the above ranges, defining the second lens to have an appropriate positive optical power and a suitable surface shape has the effect of converging light rays, depressing the height of peripheral light rays, and is beneficial for reducing the aperture of the rear lens. More specifically, 4.94 < f2 / f < 5.36; 2.28 < R3 / f < 2.44; 3.49 < R4 / f < 3.77.

[0069] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -4.3 < f3 / f < -4. Meeting the above ranges, it has the effect of diverging light rays, can disperse the central light rays and edge light rays of each field of view, and enables the rear optical system to have a larger light receiving surface to receive the light rays emerging from the image side surface of the third lens, achieving a larger light input quantity and being beneficial for increasing the relative illuminance. More specifically, -4.25 < f3 / f < -4.09.

[0070] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.4 < f7 / f < 1.5. Satisfying the above range, defining that the seventh lens has a positive optical power is beneficial to light convergence, enabling the light path to smoothly transition to the rear, reducing the height of the light incident on the rear, slowing down the upward trend of the light, avoiding light energy loss caused by an excessive chief ray angle between the large-field light and the chip when reaching the imaging surface, being conducive to improving the illuminance of the edge field of view, and being beneficial to achieving a short overall optical length. More specifically, 1.43 < f7 / f < 1.47.

[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.3 < f4 / f < 2.5; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: -44 < R7 / f < -42; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -1.5 < R8 / f < -1.4; the object-side curvature radius R7 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy: 0.9 < (R7 - R8) / (R7 + R8) < 1. Satisfying the above range is beneficial to light convergence, enabling the diverging light to smoothly enter the rear optical system and better achieving high-quality imaging of the lens; at the same time, it can effectively correct the distortion of the edge field of view, reduce the degree of deformation of the edge of the captured image, and improve the image quality. More specifically, 2.36 < f4 / f < 2.47; -43.96 < R7 / f < -42.3; -1.49 < R8 / f < -1.42; 0.92 < (R7 - R8) / (R7 + R8) < 0.94.

[0072] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.7 < f5 / f < 1.9; the object-side curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: 1 < R9 / f < 1.1; the image-side curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: 42 < R10 / f < 44; the object-side curvature radius R9 of the fifth lens and the image-side curvature radius R10 of the fifth lens satisfy: -1 < (R9 - R10) / (R9 + R) < -0.9. Satisfying the above range defines that the fifth lens has an appropriate positive optical power and a suitable surface shape, which is beneficial to light convergence. And the cooperation of the fifth lens with positive optical power and the sixth lens with negative optical power can adjust the optical path difference between different fields of view, improve the resolution, be beneficial to the smooth entry of light into the rear lens, and further reduce the field curvature and correct the off-axis aberration of the optical lens. More specifically, 1.76 < f5 / f < 1.84; 1.02 < R9 / f < 1.08; 42.3 < R10 / f < 43.96; -0.96 < (R9 - R10) / (R9 + R10) < -0.94.

[0073] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.4 < f6 / f < -1.2; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: 42 < R11 / f < 44; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: 0.8 < R12 / f < 1. Satisfying the above ranges, defining that the sixth lens has an appropriate negative optical power can diverge the light rays emitted by the fifth lens, making the light rays in the peripheral field of view show an upward trend, which is beneficial for the image points on the imaging surface to be away from the optical axis, so as to facilitate achieving the effect of matching with a large chip, obtaining a larger picture, effectively eliminating aberration, and improving the resolution ability of the optical lens. More specifically, -1.34 < f6 / f < -1.28; 42.3 < R11 / f < 43.96; 0.88 < R12 / f < 0.93.

[0074] In some embodiments, the combined focal length f56 of the fifth lens and the sixth lens and the focal length f of the optical lens satisfy: -51 < f56 / f < -28. Satisfying the above ranges, defining the focal length relationship between the cemented lens group and the rear diaphragm lens group 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, improve the imaging quality of the optical lens; and can also reduce the assembly sensitivity of the optical lens. More specifically, -50.61 < f56 / f < -28.55.

[0075] In some embodiments, the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -1.9 < f123 / f4567 < -1.7. Satisfying the above ranges, by reasonably setting the focal lengths of the lens groups before and after the diaphragm, it is beneficial to balance various aberrations of the system and improve the overall imaging quality. More specifically, -1.88 < f123 / f4567 < -1.77.

[0076] 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: 2 < IH / EPD < 2.2. Satisfying the above ranges is beneficial to increasing the light transmission amount, making the peripheral field of view and the central field of view brighter and more uniform. More specifically, 2 < IH / EPD < 2.12.

[0077] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.1 < IH / f < 1.2. Satisfying the above ranges, controlling the image height and focal length of the optical lens within a reasonable range helps the optical lens to have the characteristic of a large image surface and improve the imaging quality. More specifically, 1.12 < IH / f < 1.18.

[0078] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.6 < BFL / f < 0.7. Meeting the above range defines that the optical lens has an appropriate back focus, facilitating the reasonable arrangement of the positions of each lens and reducing the processing and assembly difficulty. More specifically, 0.6 < BFL / f < 0.65.

[0079] In some embodiments, the overall optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis satisfy: 0.74 < ∑CT / TTL < 0.77. Meeting the above range and reasonably configuring the overall optical length of the optical lens and the sum of the thicknesses of each lens helps to achieve high-pixel characteristics and improve the imaging quality of the optical lens.

[0080] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis and the effective focal length f of the optical lens satisfy: 4.08 < ΣCT / f < 4.21. Meeting the above range can effectively correct the field curvature and distortion of the optical lens and improve the imaging quality of the optical lens.

[0081] In some embodiments, the optical lens satisfies the following conditional expressions: 6.5 mm < f < 7.5 mm; 3.6 mm < EPD < 4.1 mm; 37 mm < TTL < 39 mm; 1.7 < Fno < 1.9; 23° < CRA < 25°; 4.2 mm < BFL < 4.5 mm; 60° < FOV < 70°; 7.5 mm < IH < 8.5 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the overall optical length of the optical lens, Fno represents the aperture value of the optical lens, CRA represents the chief ray angle of incidence of the optical lens, BFL represents the back focal length of the optical lens, FOV represents the maximum field angle of the optical lens, and IH represents the true image height corresponding to the maximum field angle of the optical lens. Meeting the above range, the optical lens has at least one or more advantages such as a large target surface, a large aperture, and a long focal length characteristic. More specifically, 6.82 mm < f < 7.1 mm; 3.77 mm < EPD < 4 mm; 37.82 mm < TTL < 38.93 mm; 1.74 < Fno < 1.81; 23.63° < CRA < 24.16°; 4.25 mm < BFL < 4.41 mm; 62° < FOV < 67°; 7.9 mm < IH < 8.1 mm.

[0082] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens is made of plastic, production costs can be effectively reduced. Conversely, when the lens is made of glass, the low dispersion characteristic of glass itself can effectively correct the geometric chromatic aberration of the optical system. The optical lens provided by the present invention can employ an all-glass lens structure, which can reduce dispersion, effectively correct chromatic aberration of the optical lens, and improve image quality.

[0083] 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, the first, second, third, fourth, fifth, and sixth lenses of this invention are spherical lenses, and the seventh lens is an aspherical lens.

[0084] 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:

[0085]

[0086] 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, and F are the fourth, sixth, eighth, tenth, and twelfth order surface coefficients, respectively.

[0087] 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.

[0088] Example 1

[0089] 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, 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, a seventh lens L7, a filter G1, and a protective glass G2.

[0090] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0091] The second lens L2 has positive optical power, its object side S3 is convex, and its image side S4 is concave.

[0092] The third lens L3 has negative optical power, its object side S5 is concave, and its image side S6 is convex.

[0093] The fourth lens L4 has positive optical power, its object side S7 is concave, and its image side S8 is convex.

[0094] The fifth lens L5 has positive optical power, its object side S9 is convex, and its image side is concave.

[0095] The sixth lens L6 has negative optical power, its object side is convex, and its image side S11 is concave.

[0096] The fifth lens L5 and the sixth lens L6 form a cemented lens group with negative optical power, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens L6 is S10.

[0097] The seventh lens L7 has positive optical power, its object side surface S12 is convex, and its image side surface S13 is concave.

[0098] The object-side surface S14 and the image-side surface S15 of filter G1 are both planar.

[0099] The object side S16 and the image side S17 of the protective glass G2 are both flat.

[0100] The imaging plane S18 is a plane.

[0101] The seventh lens L7 is a glass aspherical lens, while the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are glass spherical lenses.

[0102] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0103] Table 1-1

[0104]

[0105] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0106] Table 1-2

[0107] Face number K B C D E F S12 -2.62E+00 1.38E-03 -2.72E-05 1.52E-06 -7.31E-08 1.45E-09 S13 1.24E+01 9.06E-04 3.49E-05 -2.48E-06 3.36E-07 -1.02E-08

[0108] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown.

[0109] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.03 mm, indicating that the optical lens 100 can effectively correct the field curvature.

[0110] Figure 3 The F-Tan (Theta) distortion curve of Example 1 is shown, which represents the distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the distortion of the optical lens is controlled within -10% to 0, indicating that the optical lens 100 can effectively correct distortion.

[0111] Figure 4 The diagram shows the axial aberration curves for Example 1, which represent the aberrations of each wavelength along the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the diagram, the axial aberration offset is controlled within -0.01 mm to 0.03 mm, indicating that the optical lens 100 can effectively correct axial aberrations.

[0112] Figure 5 The diagram shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.55 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 -1 μm to 4 μm, indicating that the optical lens 100 can correct chromatic aberration very well.

[0113] Figure 6The 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 spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.38 throughout the entire field of view. Within the range of 0–160 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.

[0114] Example 2

[0115] Please see Figure 7 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 and lens thickness of each lens surface are different.

[0116] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0117] Table 2-1

[0118]

[0119]

[0120] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0121] Table 2-2

[0122] Face number K B C D E F S12 -2.67E+00 1.35E-03 -2.88E-05 1.58E-06 -7.62E-08 1.37E-09 S13 1.24E+01 9.03E-04 3.27E-05 -2.40E-06 3.36E-07 -1.16E-08

[0123] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 200 are respectively as follows: Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 As shown.

[0124] from Figure 8 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.03mm, indicating that the optical lens 200 can effectively correct the field curvature.

[0125] from Figure 9 As can be seen, the distortion of the optical lens is controlled within -10% to 0, indicating that the optical lens 200 can effectively correct distortion.

[0126] from Figure 10As can be seen, the axial aberration offset is controlled within -0.01mm to 0.03mm, indicating that the optical lens 200 can correct the axial aberration well.

[0127] from Figure 11 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 4μm, indicating that the optical lens 200 can correct chromatic aberration very well.

[0128] from Figure 12 As can be seen, the MTF value of this embodiment is above 0.35 throughout the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0129] Example 3

[0130] Please see Figure 13 The figure shown is a schematic diagram of the structure 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 and lens thickness of each lens surface are different.

[0131] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0132] Table 3-1

[0133]

[0134]

[0135] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0136] Table 3-2

[0137] Face number K B C D E F S12 -2.67E+00 1.37E-03 -2.79E-05 1.54E-06 -7.41E-08 1.43E-09 S13 1.20E+01 8.98E-04 3.32E-05 -2.45E-06 3.31E-07 -1.08E-08

[0138] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 300 are respectively as follows: Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 As shown.

[0139] from Figure 14 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.03mm, indicating that the optical lens 300 can effectively correct the field curvature.

[0140] from Figure 15 As can be seen, the distortion of the optical lens is controlled within -10% to 0, indicating that the optical lens 300 can effectively correct distortion.

[0141] from Figure 16 As can be seen, the axial aberration offset is controlled within -0.01mm to 0.03mm, indicating that the optical lens 300 can correct axial aberration well.

[0142] from Figure 17 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 4μm, indicating that the optical lens 300 can correct chromatic aberration very well.

[0143] from Figure 18 As can be seen, the MTF value of this embodiment is above 0.4 throughout the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0144] Example 4

[0145] Please see Figure 19 The figure shown is a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0146] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0147] Table 4-1

[0148]

[0149] The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0150] Table 4-2

[0151] Face number K B C D E F S12 -2.60E+00 1.40E-03 -2.66E-05 1.50E-06 -7.07E-08 1.43E-09 S13 1.26E+01 8.83E-04 3.76E-05 -2.55E-06 3.22E-07 -8.36E-09

[0152] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 400 are respectively as follows: Figure 20 , Figure 21 , Figure 22 , Figure 23 , Figure 24 As shown.

[0153] from Figure 20As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.03mm, indicating that the optical lens 400 can effectively correct the field curvature.

[0154] from Figure 21 As can be seen, the distortion of the optical lens is controlled within -10% to 0, indicating that the optical lens 400 can effectively correct distortion.

[0155] from Figure 22 As can be seen, the axial aberration offset is controlled within -0.01mm to 0.03mm, indicating that the optical lens 400 can correct axial aberration well.

[0156] from Figure 23 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 4μm, indicating that the optical lens 400 can correct chromatic aberration very well.

[0157] from Figure 24 As can be seen, the MTF value of this embodiment is above 0.38 throughout the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0158] Please refer to Table 5 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0159] Table 5

[0160]

[0161]

[0162] In summary, the optical lens provided by the present invention employs seven lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as large target surface, large aperture, and high imaging quality.

[0163] 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.

[0164] 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, in total seven pieces of lenses, characterized in that, In order from the object side to the imaging plane along the optical axis, the optical lens comprises in sequence: a first lens with negative refractive power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; a second lens with positive refractive power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; a third lens with negative refractive power, the object side surface of which is a concave surface and the image side surface of which is a convex surface; a fourth lens with positive refractive power, the object side surface of which is a concave surface and the image side surface of which is a convex surface; a fifth lens with positive refractive power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; a sixth lens with negative refractive power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; a seventh lens with positive refractive power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; wherein the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy -1.8 < f3 / f4 < -1.6; the focal length f3 of the third lens and the focal length f5 of the fifth lens satisfy -2.5 < f3 / f5 < -2.2; the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy 5.4 < TTL / f < 5.6; and the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy 4.7 < TTL / IH < 4.

9.

2. The optical lens of claim 1, wherein, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy -1.75 < f3 / f4 < -1.68; the focal length f3 of the third lens and the focal length f5 of the fifth lens satisfy -2.41 < f3 / f5 < -2.26; the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy 5.4 < TTL / f < 5.58; and the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy 4.72 < TTL / IH < 4.

88.

3. The optical lens of claim 1, wherein, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy -2.4 < f1 / f < -2.2; the object side surface radius of curvature R1 of the first lens and the effective focal length f of the optical lens satisfy 2.6 < R1 / f < 3; and the image side surface radius of curvature R2 of the first lens and the effective focal length f of the optical lens satisfy 0.8 < R2 / f < 0.

9.

4. The optical lens of claim 1, wherein, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy 4.9 < f2 / f < 5.4; the object side surface radius of curvature R3 of the second lens and the effective focal length f of the optical lens satisfy 2.2 < R3 / f < 2.5; and the image side surface radius of curvature R4 of the second lens and the effective focal length f of the optical lens satisfy 3.4 < R4 / f < 3.

8.

5. The optical lens of claim 1, wherein, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy -4.3 < f3 / f < -4; and the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy 1.4 < f7 / f < 1.

5.

6. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f4 of the fourth lens satisfy: 2.3 < f4 / f < 2.5; a curvature radius R7 on an object side of the fourth lens and the effective focal length f of the optical lens satisfy: -44 < R7 / f < -42; a curvature radius R8 on an image side of the fourth lens and the effective focal length f of the optical lens satisfy: -1.5 < R8 / f < -1.

4.

7. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f5 of the fifth lens satisfy: 1.7 < f5 / f < 1.9; a curvature radius R9 on an object side of the fifth lens and the effective focal length f of the optical lens satisfy: 1 < R9 / f < 1.1; a curvature radius R10 on an image side of the fifth lens and the effective focal length f of the optical lens satisfy: 42 < R10 / f < 44.

8. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f6 of the sixth lens satisfy: -1.4 < f6 / f < -1.2; a curvature radius R11 on an object side of the sixth lens and the effective focal length f of the optical lens satisfy: 42 < R11 / f < 44; a curvature radius R12 on an image side of the sixth lens and the effective focal length f of the optical lens satisfy: 0.8 < R12 / f < 1.

9. The optical lens of claim 1, wherein, A combined focal length f56 of the fifth lens and the sixth lens and the focal length f of the optical lens satisfy: -51 < f56 / f < -28; a combined focal length f123 of the first lens, the second lens and the third lens and a combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -1.9 < f123 / f4567 < -1.

7.

10. The optical lens of claim 1, wherein, A curvature radius R7 on an object side of the fourth lens and a curvature radius R8 on an image side of the fourth lens satisfy: 0.9 < (R7-R8) / (R7+R8) < 1; a curvature radius R9 on an object side of the fifth lens and a curvature radius R10 on an image side of the fifth lens satisfy: -1 < (R9-R10) / (R9+R10) < -0.9.

Images