Optical lens

Abstract

The invention provides an optical lens, which comprises seven lenses with focal power and sequentially comprises a first lens with negative focal power, a second lens with positive focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power from an object side to an imaging surface along an optical axis, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; the third lens has negative focal power; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has positive focal power, and the image side surface of the fifth lens is a convex surface; the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a concave surface; the seventh lens has negative focal power; the optical total length TTL of the optical lens, the real image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens meet the following conditions: 0.17 lt; 1 degree * TTL / (IH / 2) / (FOV / 2) lt; and 0.24. According to the optical lens provided by the invention, the imaging quality of the optical lens can be improved, the aberration is reduced, and the imaging quality of the optical lens is improved.

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] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An optical lens has seven lenses with optical power, arranged sequentially along the optical axis from the object side to the imaging plane: The first lens with negative optical power has a convex object side and a concave image side. A second lens with negative optical power has a concave object side and a convex image side. A third lens with negative optical power; The fourth lens with positive optical power has a convex object-side surface and a convex image-side surface. The fifth lens with positive optical power has a convex image-side surface; The sixth lens has negative optical power, with both its object-side and image-side surfaces being concave. A seventh lens with negative optical power; Wherein, the total optical length TTL of the optical lens, the true image height IH corresponding to the maximum field of view of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 0.17<1°×TTL / (IH / 2) / (FOV / 2)<0.24.

[0006] Further preferably, the optical lens satisfies one or more of the following conditional expressions: the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 3.5 < TTL / f < 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: 3 < TTL / IH < 4.

[0007] Further preferably, the optical lens satisfies one or more of the following conditional expressions: 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: 1.9 < IH / EPD < 2.1; 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 < 1.3.

[0008] 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 maximum field angle FOV of the optical lens satisfy: 50° < f×FOV / IH < 60°.

[0009] Further preferably, the optical lens satisfies one or more of the following conditional expressions: the half-aperture d1 of the object side of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 1.93 < d1 / (IH / 2) / tan(FOV / 2) < 2.87; the true image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens, and the FOV of the maximum field angle of the optical lens satisfy: 0.86 < (IH / 2) / (f×tan(FOV / 2)) < 0.93.

[0010] Further preferably, the optical lens satisfies one or more of the following conditional expressions: the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -7.5 < f1 / f < -2; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -13 < f2 / f < -9; the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -14 < f3 / f < -12; the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < f5 / f < 1.2; the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -14 < f7 / f < -7.

[0011] Further preferably, the optical lens satisfies one or more of the following conditional expressions: The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f4 / f < 1.6; The object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.8 < R7 / f < 1.3; The image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -26 < R8 / f < -2.4.

[0012] Further preferably, the optical lens satisfies one or more of the following conditional expressions: The focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.4 < f6 / f < -0.8; The object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.2 < R11 / f < -0.7; The image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: 2.8 < R12 / f < 17.

[0013] Further preferably, the optical lens satisfies one or more of the following conditional expressions: The combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f1234 / f < 3; The combined focal length f56 of the fifth lens and the sixth lens and the combined focal length f567 of the fifth lens, the sixth lens, and the seventh lens satisfy: 0.75 < f56 / f567 < 2.3.

[0014] Further preferably, the optical lens satisfies one or more of the following conditional expressions: The focal length f1 of the first lens and the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens satisfy: -7.5 < f1 / f1234 < -0.7; The focal length f4 of the fourth lens and the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens satisfy: 0.5 < f4 / f1234 < 1.1.

[0015] The optical lens provided by the present invention uses 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 enhance the imaging quality of the optical lens, making the lens have one or more advantages such as miniaturization, large aperture, large image surface, high pixel count, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, where: Figure 1This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0017] Figure 2 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 3 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 4 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 5 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0021] Figure 6 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0022] Figure 7 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0023] Figure 8 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.

[0024] Figure 9 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0025] Figure 10 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0026] Figure 11 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0027] Figure 12 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0028] Figure 13 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 14 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.

[0030] Figure 15 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0031] Figure 16 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0032] Figure 17This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0033] Figure 18 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0034] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] The optical lens of this invention has seven lenses with optical power, arranged sequentially along the optical axis from the object side to the imaging plane: first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, and seventh lens.

[0043] In some embodiments, the first lens may have negative optical power, with its object-side surface being convex and its image-side surface being concave. The second lens may have negative optical power, with its object-side surface being concave and its image-side surface being convex. The third lens may have negative optical power, with its object-side surface being either concave or convex, and its image-side surface being either concave or convex. The fourth lens may have positive optical power, with its object-side surface being convex and its image-side surface being convex. The fifth lens may have positive optical power, with its object-side surface being either concave or convex, and its image-side surface being convex. The sixth lens may have negative optical power, with its object-side surface being concave and its image-side surface being concave. The seventh lens may have negative optical power, with its object-side surface being either concave or convex, and its image-side surface being either concave or convex.

[0044] In some embodiments, the optical lens may also include an aperture stop, which may be located between the fourth and fifth lenses. It is understood that the aperture stop is used to limit the amount of light entering the lens, thereby altering the brightness of the image.

[0045] In some embodiments, the optical lens may further include a filter disposed between the seventh lens and the imaging plane. The filter is used to filter out interfering light and prevent it from reaching the imaging plane of the optical lens and affecting normal imaging.

[0046] In some embodiments, the fifth lens and the sixth lens can be cemented together to form a cemented lens group with positive optical power, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberrations 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.

[0047] In some embodiments, the total optical length TTL of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.17 < 1° × TTL / (IH / 2) / (FOV / 2) < 0.24. Meeting the above range can achieve a balance among the image height, focal length, and total optical length, and improve the imaging quality of the optical lens.

[0048] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 3.5 < TTL / f < 5. Meeting the above range can effectively limit the length of the lens and is beneficial to the miniaturization of the optical lens. More specifically, 3.86 < TTL / f < 4.9.

[0049] In some embodiments, 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: 3 < TTL / IH < 4. Meeting the above range ensures a larger image plane under the condition of the same total lens length, can match a larger-sized imaging chip to achieve high-definition imaging, and can better achieve the balance between the small total length and the large image plane of the lens. More specifically, 3.04 < TTL / IH < 3.98.

[0050] 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: 1.9 < IH / EPD < 2.1. Meeting the above range is beneficial to increasing the light transmission amount and making the peripheral field and the central field brighter and more uniform. More specifically, 1.92 < IH / EPD < 2.06.

[0051] 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 < 1.3. Meeting the above range controls the image height and focal length of the optical lens within a reasonable range, helps the optical lens have the characteristic of a large image plane, and improves the imaging quality. More specifically, 1.18 < IH / f < 1.28.

[0052] 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 maximum field angle FOV of the optical lens satisfy: 50° < f × FOV / IH < 60°. Meeting the above conditional formula is beneficial to achieving the balance between the field angle and large-target-plane imaging of the optical lens by reasonably restricting the relationship among the focal length, field angle, and image height of the optical lens, and better meets the use requirements of high-image-quality shooting of the optical lens. More specifically, 54.39° < f × FOV / IH < 57.85°.

[0053] In some embodiments, the clear aperture radius d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 1.93 < d1 / (IH / 2) / tan(FOV / 2) < 2.87. Meeting the above range can ensure the balance between the size of the optical lens, the field angle, and the image plane.

[0054] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens, and the FOV of the maximum field angle of the optical lens satisfy: 0.86 < (IH / 2) / (f × tan(FOV / 2)) < 0.93. Meeting the above requirements indicates that the optical distortion of the optical lens is well controlled, improving the resolution of the optical lens.

[0055] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -7.5 < f1 / f < -2. Meeting the above range, the first lens has an appropriate negative focal length, which is beneficial for the first lens to collect light rays at a larger angle and collect as much light as possible into the rear optical system, increasing the light flux while achieving a large field of view. More specifically, -7.36 < f1 / f < -2.15.

[0056] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -13 < f2 / f < -9; 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 < R3 / f < -1.3; 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: -2.5 < R4 / f < -1.8; 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: -0.2 < (R3 - R4) / (R3 + R4) < -0.11. Meeting the above range, the second lens has a negative focal length and a suitable surface shape, which can further diverge light rays and increase the field angle of the imaging system. More specifically, -12.81 < f2 / f < -9.26; -1.88 < R3 / f < -1.31; -2.41 < R4 / f < -1.88.

[0057] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -14 < f3 / f < -12. Meeting the above range, it has the effect of diverging light rays, which can disperse the central light rays and marginal light rays of each field of view, enabling 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, and being beneficial for increasing the relative illumination. More specifically, -13.98 < f3 / f < -12.74.

[0058] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < f5 / f < 1.2. Meeting the above range, defining that the fifth lens has an appropriate positive optical power and surface shape is conducive to light convergence. And by combining the fifth lens with positive optical power and the sixth lens with negative optical power, the optical path difference between different fields of view can be adjusted, the resolution can be improved, which is beneficial to making the light enter the rear lens smoothly, further reducing the field curvature and correcting the off-axis aberration of the optical lens. More specifically, 0.78 < f5 / f < 1.13.

[0059] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -14 < f7 / f < -7; the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: 0.4 < R13 / R14 < 2. The seventh lens has an appropriate negative focal length and surface shape, which is beneficial to further increasing the imaging area of the optical lens. More specifically, -13.07 < f7 / f < -7.22; 0.44 < R13 / R14 < 1.9.

[0060] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f4 / f < 1.6; the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 0.8 < R7 / f < 1.3; the curvature radius R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -26 < R8 / f < -2.4; the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: -1 < (R7 + R8) / (R7 - R8) < -0.4. Meeting the above range is beneficial to the convergence of light, enabling the diverging light to enter the rear optical system smoothly, 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 deformation degree of the edge of the captured image, and improve the image quality. More specifically, 1.08 < f4 / f < 1.56; 0.81 < R7 / f < 1.22; -25.14 < R8 / f < -2.46; -0.95 < (R7 + R8) / (R7 - R8) < -0.41.

[0061] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.4 < f6 / f < -0.8; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.2 < R11 / f < -0.7; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: 2.8 < R12 / f < 17; the object-side curvature radius R11 of the sixth lens and the image-side curvature radius R12 of the sixth lens satisfy: -0.9 < (R11 + R12) / (R11 - R12) < -0.5. Meeting the above ranges and defining the sixth lens to have an appropriate negative optical power and surface shape can diverge the light rays emerging from 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 aberrations, and improving the resolution ability of the optical lens. More specifically, -1.32 < f6 / f < -0.83; -1.15 < R11 / f < -0.74; 2.88 < R12 / f < 16.97; -0.88 < (R11 + R12) / (R11 - R12) < -0.58.

[0062] In some embodiments, the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f1234 / f < 3. Meeting the above range and reasonably setting the focal length of the lens group before the aperture is beneficial for balancing various aberrations of the system and improving the overall imaging quality. More specifically, 1 < f1234 / f < 2.94.

[0063] In some embodiments, the combined focal length f56 of the fifth lens and the sixth lens and the combined focal length f567 of the fifth lens, the sixth lens, and the seventh lens satisfy: 0.75 < f56 / f567 < 2.3. Meeting the above range is beneficial for correcting the chromatic aberration and field curvature of the lens, as well as slowing down the light deflection angle, reducing sensitivity, and reducing the lens molding difficulty. More specifically, 0.79 < f56 / f567 < 2.23.

[0064] In some embodiments, the focal length f1 of the first lens and the combined focal length f1234 of the first, second, third, and fourth lenses satisfy: -7.5 < f1 / f1234 < -0.7; the focal length f4 of the fourth lens and the combined focal length f1234 of the first, second, third, and fourth lenses satisfy: 0.5 < f4 / f1234 < 1.1. While ensuring that as much light as possible enters the system, increasing the area of the light entering the imaging surface is beneficial for achieving large image surface imaging of the lens, while also increasing the light input and improving the relative illuminance of the system. More specifically, -7.26 < f1 / f1234 < -0.73; 0.51 < f4 / f1234 < 1.08.

[0065] In some embodiments, the distance BL on the optical axis from the image side surface of the seventh lens to the imaging surface and the effective focal length f of the optical lens satisfy: 0.32 < BL / f < 0.68. Meeting the above range is beneficial for achieving a balance between obtaining good imaging quality and easy assembly, ensuring the imaging quality of the optical lens while avoiding interference between the lens and other components, and reducing the assembly process difficulty of the camera module.

[0066] In some embodiments, the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: 0.2 < f1 / f7 < 0.6. By reasonably setting the focal length relationship between the first and last lenses in the lens, while ensuring that as much light as possible enters the system, increasing the area of the light entering the imaging surface is beneficial for achieving large image surface imaging of the lens, while also increasing the light input and improving the relative illuminance of the system. More specifically, 0.23 < f1 / f7 < 0.57.

[0067] In some embodiments, the focal length f4 of the fourth lens and the focal length f5 of the fifth lens satisfy: 0.9 < f4 / f5 < 2. It is beneficial for the light before and after the aperture to transition smoothly, which is beneficial for correcting aberrations and improving the imaging quality of the optical lens. More specifically, 0.96 < f4 / f5 < 1.93.

[0068] In some embodiments, the optical lens satisfies the following conditional expressions: 7mm < f < 8mm; 4.5mm < EPD < 4.9mm; 28mm < TTL < 38mm; 1.5 < Fno < 1.7; 21° < CRA < 37°; 2.5mm < BL < 5mm; 65° < FOV < 75°; 9mm < IH < 10mm. 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 principal ray incident angle at the maximum image height of the optical lens, BL represents the distance from the image side of the seventh lens to the imaging plane on the optical axis, 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 ranges, the optical lens has at least one or more advantages such as miniaturization, large image plane, large aperture, and large field angle. More specifically, 7.42mm < f < 7.83mm; 4.58mm < EPD < 4.83mm; 28.78mm < TTL < 37.01mm; 1.61 < Fno < 1.63; 21.06° < CRA < 36.06°; 2.56mm < BL < 4.95mm; 68° < FOV < 70°; 9.31mm < IH < 9.44mm.

[0069] In some embodiments, the lens material of the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. On the other hand, when the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present invention can adopt an all-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

[0070] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better achieving the miniaturization of the lens. More specifically, the seventh lens of the present invention adopts an aspherical lens; the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens adopt spherical lenses.

[0071] In various embodiments of the present invention, when the lens adopts an aspherical lens, the surface shapes of the aspherical surfaces of the optical lens satisfy the following equations: ; 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.

[0072] 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.

[0073] Example 1 Please see Figure 1 The diagram shown is a structural schematic of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens includes, in sequence along the optical axis from the object side to the imaging plane: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, and a filter G1.

[0074] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave. The second lens L2 has negative optical power, its object side S3 is concave, and its image side S4 is convex. The third lens L3 has negative optical power, its object side S5 is concave, and its image side S6 is convex. The fourth lens L4 has positive optical power, and its object side S7 is convex, and its image side S8 is convex. The fifth lens L5 has positive optical power, its object side S9 is convex, and its image side is convex. The sixth lens L6 has negative optical power, its object side is concave, and its image side S11 is concave. The fifth lens L5 and the sixth lens L6 form a cemented lens group with positive 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. The seventh lens L7 has negative optical power. Its object-side surface S12 is convex near the optical axis, and its image-side surface S13 is concave near the optical axis. The object-side surface S14 and the image-side surface S15 of filter G1 are both planar. The imaging plane S16 is a plane.

[0075] 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, while the seventh lens L7 is a glass aspherical lens.

[0076] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0077] Table 1-1 The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0078] Table 1-2 In this embodiment, the F-Tan (Theta) distortion curve, field curvature 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.

[0079] Figure 2 The F-Tan(Theta) distortion curve of Example 1 is shown, which represents the F-Tan(Theta) distortion of light at different image heights on the imaging plane. The horizontal axis represents the F-Tan(Theta) distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tan(Theta) distortion of the optical lens is controlled within -16% to 0, indicating that the optical lens can correct distortion well.

[0080] Figure 3 The field curvature curves of Example 1 are shown, representing the degree of curvature of light rays 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 -0.02 mm to 0.06 mm, indicating that the optical lens can effectively correct the field curvature.

[0081] Figure 4 The axial aberration curves for Example 1 are shown, representing 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 figure, the axial aberration offset is controlled within -0.01 mm to 0.02 mm, indicating that the optical lens can effectively correct axial aberrations.

[0082] Figure 5The transverse chromatic aberration curve of Example 1 is shown, 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 figure, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -3 μm to 4 μm, indicating that the optical lens can effectively correct chromatic aberration.

[0083] Figure 6 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents 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 0.4 throughout the entire field of view. Within the range of 0–120 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.

[0084] Example 2 Please see Figure 7 The figure shows a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The optical lens in this embodiment is roughly the same as that in Embodiment 1. The main difference is that the object side surface S9 of the fifth lens L5 is concave; the optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0085] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0086] Table 2-1 The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0087] Table 2-2 In this embodiment, the F-Tan (Theta) distortion curve, field curvature 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.

[0088] from Figure 8 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -8% to 0, indicating that the optical lens can correct distortion well.

[0089] from Figure 9 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.1mm to 0.03mm, indicating that the optical lens can effectively correct the field curvature.

[0090] from Figure 10 As can be seen, the axial aberration offset is controlled within -0.01mm to 0.04mm, indicating that the optical lens can effectively correct axial aberration.

[0091] from Figure 11 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -3μm to 5μm, indicating that the optical lens can correct chromatic aberration well.

[0092] from Figure 12 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 120 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.

[0093] Example 3 Please see Figure 13 The diagram shows a schematic of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The optical lens in this embodiment is generally the same as that in Embodiment 1, except that: the object side S5 of the third lens L3 is convex; the image side S6 of the third lens L3 is concave; the object side S12 of the seventh lens L7 is concave; the image side S13 of the seventh lens L7 is convex; and the optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0094] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0095] Table 3-1 The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0096] Table 3-2 In this embodiment, the F-Tan (Theta) distortion curve, field curvature 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.

[0097] from Figure 14As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -12% to 0, indicating that the optical lens can correct distortion well.

[0098] from Figure 15 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.02mm to 0.08mm, indicating that the optical lens can effectively correct the field curvature.

[0099] from Figure 16 As can be seen, the axial aberration offset is controlled within -0.01mm to 0.01mm, indicating that the optical lens can effectively correct axial aberration.

[0100] from Figure 17 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within 0~3μm, indicating that the optical lens can correct chromatic aberration well.

[0101] 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 120 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.

[0102] Please refer to Tables 4-1 and 4-2 for the optical characteristics corresponding to 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, distance BL from the image side of the seventh lens to the imaging plane on the optical axis, and the numerical values ​​corresponding to each conditional expression in each embodiment.

[0103] Table 4-1 Table 4-2 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 miniaturization, large aperture, large image plane, high pixel count, and high imaging quality.

[0104] 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.

[0105] 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 having optical power, characterized in that, It 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 is convex and whose image side is concave; A second lens with a negative optical power, whose object side is concave and whose image side is convex; A third lens with a negative optical power; A fourth lens with a positive optical power, whose object side is convex and whose image side is convex; A fifth lens with a positive optical power, whose image side is convex; A sixth lens with a negative optical power, whose object side is concave and whose image side is concave; A seventh lens with a negative optical power; Wherein, the total optical length TTL of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.17 < 1°×TTL / (IH / 2) / (FOV / 2) < 0.

24.

2. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional formulas: The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 3.5 < TTL / f < 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: 3 < TTL / IH < 4.

3. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional formulas: 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: 1.9 < IH / EPD < 2.1; 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.

3.

4. 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 the optical lens, and the maximum field angle FOV of the optical lens satisfy: 50° < f×FOV / IH < 60°.

5. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional formulas: The clear aperture radius d1 of the object side of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 1.93 < d1 / (IH / 2) / tan(FOV / 2) < 2.87; The true image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens, and the FOV of the maximum field angle of the optical lens satisfy: 0.86 < (IH / 2) / (f×tan(FOV / 2)) < 0.

93.

6. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional formulas: The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -7.5 < f1 / f < -2; The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -13 < f2 / f < -9; The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -14 < f3 / f < -12; The focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < f5 / f < 1.2; The focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -14 < f7 / f < -7.

7. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f4 / f < 1.6; The object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.8 < R7 / f < 1.3; The image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -26 < R8 / f < -2.

4.

8. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.4 < f6 / f < -0.8; The object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.2 < R11 / f < -0.7; The image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: 2.8 < R12 / f < 17.

9. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f1234 / f < 3; The combined focal length f56 of the fifth lens and the sixth lens and the combined focal length f567 of the fifth lens, the sixth lens, and the seventh lens satisfy: 0.75 < f56 / f567 < 2.

3.

10. The optical lens according to claim 1, characterized in that, The optical lens satisfies one or more of the following conditional expressions: The focal length f1 of the first lens and the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens satisfy: -7.5 < f1 / f1234 < -0.7; The focal length f4 of the fourth lens and the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens satisfy: 0.5 < f4 / f1234 < 1.1.

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