Optical lens

Abstract

This invention provides an optical lens comprising eight 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 concave and its image side being convex; a third lens with negative optical power, its object side being convex and its image side being concave; 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, both its object side and image side being convex; a sixth lens with positive optical power, both its object side and image side being convex; a seventh lens with negative optical power, both its object side and image side being concave; and an eighth lens with positive optical power, both its object side and image side being convex. The optical lens provided by this invention can improve the imaging quality of an optical lens, reduce aberrations, and enhance the overall 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] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An optical lens comprising eight 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 concave object side and a convex image side.

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

[0012] The sixth lens has positive optical power, and both its object-side and image-side surfaces are convex.

[0013] The seventh lens with negative optical power has concave object-side and image-side surfaces;

[0014] The eighth lens, which has positive optical power, has convex surfaces on both its object side and image side.

[0015] The radius of curvature R5 of the object side surface of the third lens and the radius of curvature R7 of the object side surface of the fourth lens satisfy: -0.8 < (R5 + R7) / (R5 - R7) < 0.

[0016] Further preferably, 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: 2.1 < IH / EPD < 3.2.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: f2 / f > 13; the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: f3 / f < -10.

[0018] Further preferably, the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -1.5 < f123 / f45678 < -0.7.

[0019] Further preferably, the effective focal length f of the optical lens and the radius of curvature R5 of the object side surface of the third lens satisfy: 8.1 < R5 / f < 12.2; the effective focal length f of the optical lens and the radius of curvature R7 of the object side surface of the fourth lens satisfy: -24 < R7 / f < -9.9.

[0020] Further preferably, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: 1.2 < R5 / R6 < 2.7; the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R7 of the object side surface of the fourth lens satisfy: -0.95 < R5 / R7 < -0.4.

[0021] Further preferably, the radius of curvature R5 of the object side surface of the third lens and the focal length f3 of the third lens satisfy: -1 < R5 / f3 < -0.1; the radius of curvature R7 of the object side surface of the fourth lens and the focal length f4 of the fourth lens satisfy: -6.1 < R7 / f4 < -2.6.

[0022] Further preferably, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: 0.1 < (R5 - R6) / (R5 + R6) < 0.5.

[0023] Further preferably, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 1.1 < (R7 + R8) / (R7 - R8) < 1.8.

[0024] Further preferably, the sagittal height Sag5 of the clear aperture on the object side of the third lens and the clear aperture diameter d5 of the object side of the third lens satisfy: 0 < Sag5 / d5 < 0.1; the sagittal height Sag7 of the clear aperture on the object side of the fourth lens and the clear aperture diameter d7 of the object side of the fourth lens satisfy: -0.1 < Sag7 / d7 < 0.

[0025] The optical lens provided by the present invention adopts eight 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 aberration, and enhance the imaging quality of the optical lens, endowing the lens with one or more advantages such as a large aperture, a large field angle, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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:

[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 diagram of the optical lens in Embodiment 1 of the present invention.

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

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

[0031] Figure 5 is the axial aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

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

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

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

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

[0036] Figure 10 is the lateral chromatic aberration curve diagram of the optical lens in Embodiment 2 of the present invention.

[0037] Figure 11This is an axial 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 the F-Tan (Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.

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

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

[0044] Figure 18 This is the 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 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 a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0049] Figure 23 This is an axial 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 of this invention comprises eight lenses, 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, seventh lens, and eighth lens.

[0060] 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 positive 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 convex and its image-side surface being concave. The fourth lens may have positive optical power, with its object-side surface being concave and its image-side surface being convex. The fifth lens may have positive optical power, with both its object-side and image-side surfaces being convex. The sixth lens may have positive optical power, with both its object-side and image-side surfaces being convex. The seventh lens may have negative optical power, with both its object-side and image-side surfaces being concave. The eighth lens may have positive optical power, with both its object-side and image-side surfaces being convex.

[0061] In some embodiments, the optical lens may further include an aperture stop, which may be located between the third lens and the fourth lens. 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 lens and the fourth lens, it facilitates the correction of aperture aberrations.

[0062] In some embodiments, the optical lens may further include a filter, which may be disposed between the eighth lens and the imaging surface. The filter is used to filter out interfering light and prevent interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0063] In some embodiments, the sixth and seventh lenses can be cemented together to form a cemented lens, which can effectively correct 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.

[0064] In some embodiments, the object-side radius of curvature R5 of the third lens and the object-side radius of curvature R7 of the fourth lens satisfy: -0.8 < (R5 + R7) / (R5 - R7) < 0. Meeting this range helps to mitigate the change in the incident light refraction angle, avoiding excessive aberrations caused by overly strong refraction changes. More specifically, -0.34 < (R5 + R7) / (R5 - R7) < -0.08.

[0065] 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: 2.1 < IH / EPD < 3.2. Satisfying the above range can increase the width of the light beam entering the optical lens, improve the brightness at the image plane of the optical lens, and avoid the generation of vignetting. More specifically, 2.35 < IH / EPD < 2.85.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: f2 / f > 13. Satisfying the above range can effectively converge a large range of light entering the system, which is beneficial to avoiding excessive light deflection caused by the over-concentration of the optical power of the first lens and reducing the difficulty of aberration correction. More specifically, 14.66 < f2 / f < 131.73.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: f3 / f < -10. Satisfying the above range is beneficial to slowing down the deflection degree of the incident light, avoiding excessive aberration caused by too strong refraction change, and at the same time is beneficial to balancing various aberrations generated by the front lens group and improving the overall imaging quality. More specifically, -49.94 < f3 / f < -10.99.

[0068] In some embodiments, the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -1.5 < f123 / f45678 < -0.7. Satisfying the above range can effectively correct the aberrations generated by the lens groups before and after the aperture and improve the imaging quality of the optical lens. More specifically, -1.24 < f123 / f45678 < -0.97.

[0069] In some embodiments, the effective focal length f of the optical lens and the curvature radius R5 of the object side surface of the third lens satisfy: 8.1 < R5 / f < 12.2; the effective focal length f of the optical lens and the curvature radius R7 of the object side surface of the fourth lens satisfy: -24 < R7 / f < -9.9. Satisfying the above range is beneficial to slowing down the change degree of the refraction angle of the incident light of the lenses before and after the aperture and avoiding excessive aberration caused by too strong refraction change. More specifically, 9.13 < R5 / f < 11.01; -22.02 < R7 / f < -10.95.

[0070] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: 1.2 < R5 / R6 < 2.7; the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R7 of the object side surface of the fourth lens satisfy: -0.95 < R5 / R7 < -0.4. Satisfying the above ranges is conducive to slowing down the change degree of the refraction angle of incident light and avoiding excessive aberration caused by too strong refraction change. More specifically, 1.39 < R5 / R6 < 2.45; -0.84 < R5 / R7 < -0.49.

[0071] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the focal length f3 of the third lens satisfy: -1 < R5 / f3 < -0.1; the radius of curvature R7 of the object side surface of the fourth lens and the focal length f4 of the fourth lens satisfy: -6.1 < R7 / f4 < -2.6. Satisfying the above ranges can effectively balance lens aberration and improve imaging quality. More specifically, -0.84 < R5 / f3 < -0.21; -5.52 < R7 / f4 < -3.05.

[0072] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: 0.1 < (R5 - R6) / (R5 + R6) < 0.5. Satisfying the above ranges controls the object side surface and the image side surface of the third lens to have reasonable shapes and improves imaging quality. More specifically, 0.16 < (R5 - R6) / (R5 + R6) < 0.43.

[0073] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 1.1 < (R7 + R8) / (R7 - R8) < 1.8. Satisfying the above ranges can effectively correct aberration and improve the imaging quality of the optical lens. More specifically, 1.29 < (R7 + R8) / (R7 - R8) < 1.56.

[0074] In some embodiments, the sagittal height Sag5 of the clear aperture of the object side surface of the third lens and the clear aperture d5 of the object side surface of the third lens satisfy: 0 < Sag5 / d5 < 0.1; the sagittal height Sag7 of the clear aperture of the object side surface of the fourth lens and the clear aperture d7 of the object side surface of the fourth lens satisfy: -0.1 < Sag7 / d7 < 0. Satisfying the above ranges helps to control the trend of light rays in the edge field of view and highlight the detailed information of the central field of view of the optical lens. More specifically, 0.01 < Sag5 / d5 < 0.06; -0.04 < Sag7 / d7 < -0.01.

[0075] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f satisfy: 5.8 < TTL / f < 7.9. Meeting the above range can effectively limit the length of the lens. More specifically, 6.39 < TTL / f < 7.71.

[0076] 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: 3.9 < TTL / IH < 4.7. Meeting the above range can preferably achieve the balance between the total length of the lens and the image plane. More specifically, 4.32 < TTL / IH < 4.43.

[0077] In some embodiments, the maximum field angle FOV of the optical lens and the f-number Fno satisfy: 45° < FOV / Fno < 65°. Meeting the above requirements is beneficial to expanding the field angle of the optical lens and increasing the aperture of the optical lens, which is conducive to the optical lens obtaining more scene information, meeting the requirements of large-range detection, and is beneficial to improving the problem that the relative brightness of the edge field of view drops rapidly, and thus is also beneficial to obtaining more scene information. More specifically, 49° < FOV / Fno < 63°.

[0078] In some embodiments, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field angle satisfy: 1.3 < IH / f < 1.9. Meeting the above range ensures that the optical lens has a large imaging surface, improves the lens resolution, and at the same time enables the lens to have a larger field angle in the case of a large imaging surface, which is beneficial to achieving the balance between high pixel and ultra-wide angle of the lens. More specifically, 1.46 < IH / f < 1.78.

[0079] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL satisfy: 0.8 < BFL / f < 1.4. Meeting the above range can make the lens have a long back focus, which is beneficial to the assembly of the module, reduces interference, and improves the production yield. More specifically, 0.87 < BFL / f < 1.23.

[0080] In some embodiments, the maximum field angle FOV of the optical lens, the effective focal length f of the optical lens, and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 50° < (FOV × f) / IH < 60°. Meeting the above range can balance the requirements of large-range detection and high-quality imaging, and improve the adaptability of the optical lens. More specifically, the maximum field angle FOV of the optical lens, the effective focal length f of the optical lens, and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 54.05° < (FOV × f) / IH < 56.52°.

[0081] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.9 < f1 / f < -1.4. Meeting the above range can make the first lens have a negative optical power, which is beneficial to reducing the inclination angle of the incident light, and is conducive to collecting the marginal field light into the rear optical lens as much as possible to achieve large-angle light collection. More specifically, -1.73 < f1 / f < -1.59.

[0082] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 3.2 < f4 / f < 4.5. Meeting the above range can effectively converge the light, correct the aberration generated by the front diaphragm lens group, and improve the overall imaging quality. More specifically, 3.55 < f4 / f < 4.05.

[0083] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 2.1 < f5 / f < 3.2. Meeting the above range can make the fifth lens have a positive optical power, which is beneficial to improving the light converging ability of the optical lens, and at the same time can balance the aberration of the optical lens and improve the imaging quality of the optical lens. More specifically, 2.39 < f5 / f < 2.91.

[0084] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.3 < f6 / f < 2. Meeting the above range can make the sixth lens have a positive optical power, further improve the light converging ability of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens. More specifically, 1.48 < f6 / f < 1.84.

[0085] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -1.2 < f7 / f < -0.8. Meeting the above range can make the seventh lens have a negative optical power, which is beneficial to increasing the imaging area and field angle of the optical lens and improving the imaging quality of the optical lens. More specifically, -1.09 < f7 / f < -0.9.

[0086] In some embodiments, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: 3.2 < f8 / f < 5.7. Meeting the above range can make the eighth lens have a positive optical power, control the light trend smoothly, transfer more light to the imaging surface, and improve the imaging quality of the optical lens. More specifically, 3.63 < f8 / f < 5.11.

[0087] In some embodiments, the effective focal length f of the optical lens and the combined focal length f67 of the sixth lens and the seventh lens satisfy: -4.4 < f67 / f < -3. When within the above range, the sixth and seventh lenses form a cemented lens with a negative optical power. By reasonably setting the focal lengths of the sixth and seventh cemented lenses, chromatic aberration of the optical lens can be effectively corrected, the decentration sensitivity of the optical lens can be reduced, and the aberrations of the optical lens can be balanced, improving the imaging quality of the optical lens. More specifically, -3.97 < f67 / f < -3.3.

[0088] In some embodiments, the effective focal length f of the optical lens and the radius of curvature R11 of the object side surface of the sixth lens satisfy: 1.9 < R11 / f < 5.1. When within the above range, the light can be effectively converged, aberrations can be corrected, and the overall imaging quality can be improved. More specifically, 2.14 < R11 / f < 4.62.

[0089] 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 eighth lens along the optical axis satisfy: 0.5 < ∑CT / TTL < 0.8. When within the above range, the overall length of the optical system can be compressed, making the structure of the system more compact. More specifically, 0.6 < ∑CT / TTL < 0.65.

[0090] 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: 1.1 < d1 / (IH / 2) / tan(FOV / 2) < 1.9. When within the above range, the relationship between the front aperture diameter, the field angle, and the image plane size of the optical lens can be balanced, facilitating miniaturization. More specifically, 1.25 < d1 / (IH / 2) / tan(FOV / 2) < 1.79.

[0091] In some embodiments, the central thickness CT3 of the third lens and the distance CT34 between the third lens and the fourth lens on the optical axis satisfy: 0.2 < CT34 / CT3 < 0.9. When within the above range, good processability of the lens and reasonable arrangement within the optical system can be maintained. More specifically, 0.23 < CT34 / CT3 < 0.85.

[0092] In some embodiments, the optical lens satisfies the conditional formula: 4mm < f < 6mm, 70° < FOV < 110°, 2.6mm < EPD < 3.8mm, 31mm < TTL < 39mm, 1.4 < Fno < 1.8, 7.5mm < IH < 8.5mm, 13° < CRA < 17.5°, 4.3mm < BFL < 6mm, where f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the f-number of the optical lens, IH represents the image height corresponding to the maximum field of view angle of the optical lens, CRA represents the chief ray angle of incidence at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention has at least the characteristics of a large field of view angle, a large image plane, a large aperture, etc. More specifically, 4.53mm < f < 5.48mm, 70° < FOV < 110°, 2.83mm < EPD < 3.43mm, 34.91mm < TTL < 35.62mm, 1.5 < Fno < 1.7, 8mm < IH < 8.1mm, 14.41° < CRA < 15.94°, 4.78mm < BFL < 5.55mm.

[0093] 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.

[0094] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens, the second lens, the fourth lens, the sixth lens, and the seventh lens of the present invention adopt spherical lenses, and the third lens, the fifth lens, and the eighth lens adopt aspherical lenses.

[0095] In various embodiments of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0096]

[0097] Where z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the quadratic surface coefficient, and B, C, D, E, F, G, and H are the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order surface coefficients, respectively.

[0098] 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.

[0099] Example 1

[0100] Please see Figure 1 The figure shown is a schematic diagram of the structure of the optical lens 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, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter G1.

[0101] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0102] The second lens L2 has positive optical power, its object side S3 is concave, and its image side S4 is convex.

[0103] The third lens L3 has negative optical power, its object side S5 is convex, and its image side S6 is concave.

[0104] The fourth lens L4 has positive optical power, with its object-side surface S7 being concave and its image-side surface S8 being convex.

[0105] The fifth lens L5 has positive optical power, and both its object side S9 and image side S10 are convex surfaces;

[0106] The sixth lens L6 has positive optical power, and both its object-side surface S11 and image-side surface S12 are convex.

[0107] The seventh lens L7 has negative optical power, and both its object-side surface S12 and image-side surface S13 are concave.

[0108] The sixth lens L6 and the seventh lens L7 form a cemented lens group with negative optical power, that is, the cemented surface of the image side of the sixth lens L6 and the object side of the seventh lens L7 is S12.

[0109] The eighth lens L8 has positive optical power, and both its object-side surface S14 and image-side surface S15 are convex.

[0110] The object-side surface S16 and the image-side surface S17 of filter G1 are both planar.

[0111] The imaging plane S18 is a plane.

[0112] The first, second, fourth, sixth, and seventh lenses are glass spherical lenses, while the third, fifth, and eighth lenses are glass aspherical lenses.

[0113] The relevant parameters of each lens in the optical lens of Example 1 are shown in Table 1-1.

[0114] Table 1-1

[0115]

[0116]

[0117] The surface profile parameters of the aspherical lens in Example 1 are shown in Table 1-2.

[0118] Table 1-2

[0119] Face number K B C D E F G H S5 -9.56E+01 -2.00E-04 -8.59E-07 1.88E-07 1.44E-08 1.33E-10 -5.07E-11 1.78E-12 S6 2.85E+01 6.85E-05 -9.43E-07 3.08E-07 3.86E-09 2.54E-11 -1.48E-11 7.20E-13 S9 6.16E-01 5.71E-05 -4.09E-07 -5.22E-08 7.23E-10 1.01E-10 -7.93E-14 -3.85E-14 S10 3.41E+00 -1.04E-04 -2.64E-07 -3.19E-09 -1.94E-10 1.40E-10 -9.15E-13 -2.90E-14 S14 -7.28E+00 -1.52E-04 1.51E-06 1.22E-07 2.39E-08 1.52E-09 5.24E-11 -4.57E-12 S15 3.63E+01 4.92E-04 9.25E-06 5.10E-07 2.32E-08 1.50E-09 -2.63E-12 -5.48E-13

[0120] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, transverse chromatic aberration curve, axial aberration curve, and MTF curve of the optical lens are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown.

[0121] 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 can effectively correct the field curvature.

[0122] 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 -30% to 0, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0123] Figure 4 The diagram shows the transverse chromatic aberration curve of the optical lens 100 in this embodiment. It represents the chromatic aberration of each wavelength relative to the center wavelength (0.55 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, indicating that the optical lens 100 can effectively correct chromatic aberration.

[0124] Figure 5 The diagram shows the axial aberration curve of the optical lens 100 in this embodiment, which represents the aberration of each wavelength on 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, indicating that the optical lens 100 can correct axial aberration well.

[0125] 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 0.38 throughout the entire field of view. Within the range of 0–180 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.

[0126] Example 2

[0127] Please see Figure 7 The figure shows a schematic diagram of the optical lens 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 optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0128] The relevant parameters of each lens in the optical lens of Example 2 are shown in Table 2-1.

[0129] Table 2-1

[0130]

[0131] The surface profile parameters of the aspherical lens in Example 2 are shown in Table 2-2.

[0132] Table 2-2

[0133] Face number K B C D E F G H S5 -9.73E+01 -2.32E-04 -1.87E-06 1.99E-07 1.48E-08 5.50E-11 -5.89E-11 2.35E-12 S6 2.34E+01 3.25E-06 -3.78E-06 2.35E-07 3.84E-09 -2.56E-10 -5.04E-11 2.13E-12 S9 8.99E-01 7.99E-05 -2.52E-07 -3.52E-08 -1.42E-10 3.89E-11 -1.58E-12 -2.78E-14 S10 3.57E+00 -1.51E-04 3.89E-06 2.00E-08 -1.72E-09 8.70E-11 -1.80E-12 -1.44E-14 S14 -1.49E+01 -8.08E-04 -3.72E-05 -1.26E-07 2.95E-08 2.04E-09 1.15E-10 -9.72E-13 S15 4.61E+01 -4.98E-04 -1.49E-05 3.96E-07 3.13E-08 1.19E-09 -4.71E-11 3.77E-12

[0134] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, transverse chromatic aberration curve, axial aberration curve, and MTF curve of the optical lens are respectively as follows: Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 As shown.

[0135] from Figure 8 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.03 mm, indicating that the optical lens can effectively correct the field curvature.

[0136] from Figure 9 As can be seen, the distortion of the optical lens is controlled within -30% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image.

[0137] from Figure 10 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens 100 can correct chromatic aberration well.

[0138] from Figure 11 As can be seen, the axial aberration offset is controlled within ±0.01mm, indicating that the optical lens 100 can effectively correct axial aberration.

[0139] 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 180 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.

[0140] Example 3

[0141] Please see Figure 13 The figure shows a schematic diagram of the optical lens provided in Embodiment 3 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 optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0142] The relevant parameters of each lens in the optical lens of Example 3 are shown in Table 3-1.

[0143] Table 3-1

[0144]

[0145]

[0146] The surface profile parameters of the aspherical lens in Example 3 are shown in Table 3-2.

[0147] Table 3-2

[0148] Face number K B C D E F G H S5 9.68E+00 -8.11E-05 3.39E-06 4.04E-07 6.85E-08 -1.28E-09 -3.67E-10 1.75E-11 S6 4.42E+01 1.55E-04 -6.34E-06 1.03E-06 1.72E-08 -1.78E-09 -1.25E-10 6.79E-12 S9 3.76E-01 3.22E-05 -3.39E-08 -7.45E-08 2.05E-10 9.87E-11 -1.26E-13 -6.53E-14 S10 4.37E+00 -3.42E-05 -7.23E-07 3.47E-08 1.99E-10 1.02E-10 -2.37E-12 -1.48E-14 S14 -3.84E+01 -7.22E-04 -3.67E-05 3.63E-07 8.93E-08 1.34E-09 -1.34E-10 2.88E-12 S15 1.00E+02 6.82E-05 -2.28E-05 1.73E-06 2.67E-08 -9.49E-11 1.52E-11 1.09E-12

[0149] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, transverse chromatic aberration curve, axial aberration curve, and MTF curve of the optical lens are respectively as follows: Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 As shown.

[0150] from Figure 14 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.03 mm, indicating that the optical lens can effectively correct the field curvature.

[0151] from Figure 15 As can be seen, the distortion of the optical lens is controlled within -15% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image.

[0152] from Figure 16 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens 100 can correct chromatic aberration well.

[0153] from Figure 17 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens 100 can effectively correct axial aberration.

[0154] from Figure 18 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 180 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.

[0155] Example 4

[0156] Please see Figure 19 The figure shows a schematic diagram of the optical lens provided in Embodiment 4 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 optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0157] The relevant parameters of each lens in the optical lens of Example 4 are shown in Table 4-1.

[0158] Table 4-1

[0159]

[0160]

[0161] The surface profile parameters of the aspherical lens in Example 4 are shown in Table 4-2.

[0162] Table 4-2

[0163] Face number K B C D E F G H S5 7.14E+01 -9.58E-05 5.78E-06 7.17E-07 7.90E-08 -3.26E-09 -5.03E-10 3.45E-11 S6 3.09E+01 -7.95E-05 -1.60E-05 3.21E-07 -1.37E-08 -1.42E-09 -1.56E-10 -5.16E-11 S9 4.67E-01 4.24E-05 -1.18E-07 -7.26E-08 2.17E-10 9.72E-11 -1.99E-13 -6.86E-14 S10 4.33E+00 -2.82E-05 -2.13E-07 3.30E-08 7.78E-11 1.03E-10 -2.41E-12 -1.70E-14 S14 -2.92E+01 -7.63E-04 -3.93E-05 3.02E-07 8.41E-08 9.87E-10 -1.40E-10 4.58E-12 S15 1.00E+02 5.42E-05 -2.47E-05 1.60E-06 2.24E-08 -1.76E-10 1.61E-11 1.33E-12

[0164] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, transverse chromatic aberration curve, axial aberration curve, and MTF curve of the optical lens are respectively as follows: Figure 20 , Figure 21 , Figure 22 , Figure 23 , Figure 24 As shown.

[0165] from Figure 20 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.03 mm, indicating that the optical lens can effectively correct the field curvature.

[0166] from Figure 21 As can be seen, the distortion of the optical lens is controlled within -15% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image.

[0167] from Figure 22 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens 100 can correct chromatic aberration well.

[0168] from Figure 23 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens 100 can effectively correct axial aberration.

[0169] from Figure 24 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 180 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.

[0170] 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.

[0171] Table 5

[0172]

[0173]

[0174] In summary, the optical lens provided by the present invention uses eight 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 ultra-wide angle, high pixel count, and high imaging quality.

[0175] 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.

[0176] 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 eight lenses, characterized in that, It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with negative optical power, whose object side surface is convex and whose image side surface is concave; A second lens with positive optical power, whose object side surface is concave and whose image side surface is convex; A third lens with negative optical power, whose object side surface is convex and whose image side surface is concave; A fourth lens with positive optical power, whose object side surface is concave and whose image side surface is convex; A fifth lens with positive optical power, whose object side surface and image side surface are both convex; A sixth lens with positive optical power, whose object side surface and image side surface are both convex; A seventh lens with negative optical power, whose object side surface and image side surface are both concave; An eighth lens with positive optical power, whose object side surface and image side surface are both convex; Wherein, the curvature radius R5 of the object side surface of the third lens and the curvature radius R7 of the object side surface of the fourth lens satisfy: -0.8 < (R5 + R7) / (R5 - R7) < 0; The combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -1.5 < f123 / f45678 < -0.

7.

2. The optical lens according to claim 1, characterized in that, 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: 2.1 < IH / EPD < 3.

2.

3. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 13 < f2 / f ≤ 131.72; the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -49.93 ≤ f3 / f < -10.

4. The optical lens according to claim 1, characterized in that, The curvature radius R5 of the object side surface of the third lens and the curvature radius R7 of the object side surface of the fourth lens satisfy: -0.34 < (R5 + R7) / (R5 - R7) < -0.08; The combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -1.24 < f123 / f45678 < -0.

97.

5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the curvature radius R5 of the object side surface of the third lens satisfy: 8.1 < R5 / f < 12.2; the effective focal length f of the optical lens and the curvature radius R7 of the object side surface of the fourth lens satisfy: -24 < R7 / f < -9.

9.

6. The optical lens according to claim 1, characterized in that, The curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: 1.2 < R5 / R6 < 2.7; the curvature radius R5 of the object side surface of the third lens and the curvature radius R7 of the object side surface of the fourth lens satisfy: -0.95 < R5 / R7 < -0.

4.

7. The optical lens according to claim 1, characterized in that, The curvature radius R5 of the object side surface of the third lens and the focal length f3 of the third lens satisfy: -1 < R5 / f3 < -0.1; the curvature radius R7 of the object side surface of the fourth lens and the focal length f4 of the fourth lens satisfy: -6.1 < R7 / f4 < -2.

6.

8. The optical lens according to claim 1, characterized in that, The radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: 0.1 < (R5 - R6) / (R5 + R6) < 0.

5.

9. The optical lens according to claim 1, characterized in that, The radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 1.1 < (R7 + R8) / (R7 - R8) < 1.

8.

10. The optical lens according to claim 1, characterized in that, The sagittal height Sag5 of the clear aperture of the object side surface of the third lens and the clear aperture diameter d5 of the object side surface of the third lens satisfy: 0 < Sag5 / d5 < 0.1; the sagittal height Sag7 of the clear aperture of the object side surface of the fourth lens and the clear aperture diameter d7 of the object side surface of the fourth lens satisfy: -0.1 < Sag7 / d7 < 0.

Images