Optical lens

Abstract

The application provides an optical lens, which comprises eight lenses in sequence along an optical axis from an object side to an imaging surface, and the eight lenses comprise: a first lens with negative optical power, wherein the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; a second lens with negative optical power, wherein the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; a third lens with negative optical power; a fourth lens with positive optical power, wherein 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; a fifth lens with negative optical power; a sixth lens with positive optical power, wherein the image side surface of the sixth lens is a convex surface; a seventh lens with negative optical power, wherein the object side surface of the seventh lens is a concave surface, and the image side surface of the seventh lens is a concave surface; and an eighth lens with positive optical power, wherein the object side surface of the eighth lens is a convex surface, and the image side surface of the eighth lens is a convex surface. The optical lens provided by the application improves the imaging quality of the optical lens through reasonable configuration of the surface shape of each lens and reasonable matching of the optical power, so that the lens has one or more advantages such as a large aperture, an ultralarge field of view, high pixels, high imaging quality and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of imaging lenses, in particular to an optical lens. BACKGROUND

[0002] With the continuous improvement of people's requirements for driving experience, vehicle application type optical lenses are used more and more in intelligent driving, and the position of vehicle optical lenses in the automobile industry is continuously improved.

[0003] Advanced Driver Assistance System (ADAS) plays an important role in intelligent driving. It collects environmental information through various lenses combined with sensors to ensure the safety of drivers. The surround view lens is used to shoot the environment around the vehicle. The pictures captured by multiple cameras will be transmitted to the vehicle processor for real-time processing. The processor will correct, splice and fuse these pictures appropriately to generate a continuous, seamless and full-360-degree surround view image. The surround view lens generally uses a wide-angle lens, which has the problem of poor imaging quality and is difficult to meet user needs. Therefore, it is necessary to develop an optical lens with good imaging effect. SUMMARY

[0004] In view of the above problems, the purpose of the present application is to provide an optical lens with the advantages of excellent imaging quality.

[0005] The present application provides an optical lens, which has a total of eight lenses, and comprises, along the optical axis from the object side to the imaging surface:

[0006] a first lens with negative focal power, the object side surface of which is convex, and the image side surface of which is concave;

[0007] a second lens with negative focal power, the object side surface of which is convex, and the image side surface of which is concave;

[0008] a third lens with negative focal power;

[0009] a fourth lens with positive focal power, the object side surface of which is convex, and the image side surface of which is convex;

[0010] a fifth lens with negative focal power;

[0011] a sixth lens with positive focal power, the image side surface of which is convex;

[0012] a seventh lens with negative focal power, the object side surface of which is concave, and the image side surface of which is concave;

[0013] an eighth lens with positive focal power, the object side surface of which is convex, and the image side surface of which is convex;

[0014] The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -50 < f5 / f < -15.

[0015] It is further preferred that the total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.5 < TTL / f < 10.

[0016] It is further preferred that the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 4.8 < R1 / R2 < 6.5.

[0017] It is further preferred 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: 0 < (R7+R8) / (R7-R8) < 0.1.

[0018] It is further preferred that the central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 0.1 < CT3 / CT4 < 0.4.

[0019] It is further preferred that the back focal length BFL of the optical lens and the total track length TTL of the optical lens satisfy: 0.15 < BFL / TTL < 0.2.

[0020] It is further preferred that the central thickness CT4 of the fourth lens and the edge thickness ET4 of the fourth lens satisfy: 1.2 < CT4 / ET4 < 1.4.

[0021] It is further preferred that the radius of curvature R1 of the object side surface of the first lens, the radius of curvature R2 of the image side surface of the first lens and the central thickness CT1 of the first lens satisfy: 3.5 < R1 / (R2+CT1) < 4.3.

[0022] It is further preferred that the half diameter of the light passing through the object side surface DM11 of the first lens and the half diameter of the light passing through the image side surface DM82 of the eighth lens satisfy: 1.8 < DM11 / DM82 < 2.3.

[0023] It is further preferred that the real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 6 < IH / EPD < 6.5.

[0024] The optical lens provided by the present application adopts eight lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved, so that the lens has one or more advantages of large aperture, super large field angle, high pixel, high imaging quality, etc. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:

[0026] Figure 1 Structure diagram of the optical lens in Embodiment 1 of the present application.

[0027] Figure 2 Field curvature curve of the optical lens in Embodiment 1 of the present application.

[0028] Figure 3 F-Theta distortion curve of the optical lens in Embodiment 1 of the present application.

[0029] Figure 4 Axial aberration curve of the optical lens in Embodiment 1 of the present application.

[0030] Figure 5 Vignetting curve of the optical lens in Embodiment 1 of the present application.

[0031] Figure 6 Structure diagram of the optical lens in Embodiment 2 of the present application.

[0032] Figure 7 Field curvature curve of the optical lens in Embodiment 2 of the present application.

[0033] Figure 8 F-Theta distortion curve of the optical lens in Embodiment 2 of the present application.

[0034] Figure 9 Axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0035] Figure 10 Vignetting curve of the optical lens in Embodiment 2 of the present application.

[0036] Figure 11 Structure diagram of the optical lens in Embodiment 3 of the present application.

[0037] Figure 12 Field curvature curve of the optical lens in Embodiment 3 of the present application.

[0038] Figure 13 F-Theta distortion curve of the optical lens in Embodiment 3 of the present application.

[0039] Figure 14 Axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0040] Figure 15 Vignetting curve of the optical lens in Embodiment 3 of the present application.

[0041] Figure 16 Structure diagram of the optical lens in Embodiment 4 of the present application.

[0042] Figure 17 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0043] Figure 18 This is the F-Theta distortion curve of the optical lens in Embodiment 4 of the present invention.

[0044] Figure 19 This is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0045] Figure 20 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0046] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] The optical lens provided in this embodiment of the invention comprises eight lenses, which are arranged sequentially along the optical axis from the object side to the imaging plane as follows: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens.

[0055] 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 convex and its image-side surface being concave. 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 has positive optical power, with both its object-side and image-side surfaces being convex. The fifth lens may have negative optical power, with both its object-side and image-side surfaces being either concave or convex. The sixth lens may have positive optical power, with both its object-side and image-side surfaces being either concave or 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.

[0056] 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 to change the brightness of the image. When the aperture stop is located between the fourth and fifth lenses, it facilitates the correction of aperture aberrations.

[0057] In some embodiments, the optical lens may further include a filter disposed between the eighth lens and the imaging surface. The filter is used to filter out interfering light and prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0058] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -50 < f5 / f < -15. Meeting the above conditions can make the fifth lens have an appropriate negative optical power, which is beneficial to increasing the imaging area of the optical lens and improving the imaging quality of the optical lens.

[0059] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.5 < TTL / f < 10. Meeting the above conditions can effectively limit the length of the lens and is beneficial to the miniaturization of the optical lens.

[0060] In some embodiments, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 4.8 < R1 / R2 < 6.5. Meeting the above conditions can reasonably set the surface shape of the first lens, enhance the light collection ability of the first lens, and thus achieve an ultra-large viewing angle.

[0061] 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: 0 < (R7 + R8) / (R7 - R8) < 0.1. Meeting the above range can make the light trend more stable; at the same time, it can correct coma and field curvature, improve the flatness of imaging, and improve the imaging quality of the optical lens.

[0062] In some embodiments, the central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 0.1 < CT3 / CT4 < 0.4. Meeting the above conditions can reasonably configure the ratio of the thickness of the third lens on the optical axis to the thickness of the fourth lens on the optical axis. The third lens and the fourth lens can regulate each other and maintain the characteristics of the miniaturization of the optical system.

[0063] In some embodiments, the back focal length BFL of the optical lens and the overall optical length TTL of the optical lens satisfy: 0.15 < BFL / TTL < 0.2. Meeting the above conditions can reasonably configure the ratio of the back focal length of the optical lens to the overall optical length of the optical lens. Under the condition of ensuring sufficient space for the installation and focusing of optical elements, it is beneficial to the miniaturization of the optical lens.

[0064] In some embodiments, the central thickness CT4 of the fourth lens and the edge thickness ET4 of the fourth lens satisfy: 1.2 < CT4 / ET4 < 1.4. Meeting the above conditions, by controlling the ratio of the thickness of the fourth lens on the optical axis to the edge thickness, not only can the high-order aberrations generated by the optical lens be effectively balanced, but it is also beneficial to the field curvature adjustment of the fourth lens, thereby improving the imaging quality of the optical lens.

[0065] In some embodiments, the object-side curvature radius R1 of the first lens, the image-side curvature radius R2 of the first lens, and the central thickness CT1 of the first lens satisfy: 3.5 < R1 / (R2 + CT1) < 4.3. Meeting the above range can reduce the correction difficulty of the marginal field distortion and control the distortion within a reasonable range.

[0066] In some embodiments, the clear aperture semi-diameter DM11 of the object side of the first lens and the clear aperture semi-diameter DM82 of the image side of the eighth lens satisfy: 1.8 < DM11 / DM82 < 2.3. Meeting the above range, by reasonably setting the ratio of the apertures of the first and last lenses, the lens can have a smaller head size while having a larger imaging surface, and can better meet the balance of miniaturization and high pixels.

[0067] 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: 6 < IH / EPD < 6.5. Meeting the above range enables the optical lens to meet the large image surface while also ensuring sufficient image surface brightness in the marginal field of view, preventing the occurrence of vignetting, and thus improving the imaging quality.

[0068] In some embodiments, the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens, and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 55° < (f × FOV) / IH < 65°. Meeting the above conditional formula, by reasonably restricting the relationship between the focal length, field angle, and image height of the optical lens, it is beneficial to achieve the balance of the large field angle and large target surface imaging of the optical lens, and better meet the usage requirements of vehicle-mounted surround-view cameras.

[0069] 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: 3 < IH / f < 3.6. Meeting the above conditions can achieve an ultra-large field angle and imaging range, and can achieve the characteristics of a large image surface while ensuring the depth of field of the optical lens, thereby improving the imaging quality of the optical system.

[0070] 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: 2.6 < TTL / IH < 2.9. Meeting the above conditions can better achieve the miniaturization of the lens. At the same time, when ensuring the same total length of the lens, it has a larger image plane and can match a larger-sized imaging chip to achieve high-definition imaging.

[0071] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -2.5 < f1 / f < -1.9. Meeting the above conditions, the first lens has an appropriate negative focal length, which is beneficial to expanding the field angle of the optical lens.

[0072] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.8 < f2 / f < -3.4. Meeting the above conditions, the second lens also uses a negative lens, which can further diverge light and increase the field angle of the imaging system.

[0073] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1.8 < f4 / f < 1.9. Meeting the above conditions, the fourth lens converges the incident light at the front end, which is beneficial to correcting the aberration brought by the front lens group and the distortion of the edge field of view, making the lens have less distortion and providing a high-definition imaging effect.

[0074] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 2.3 < f6 / f < 2.7. Meeting the above conditions can make the sixth lens have an appropriate positive optical power, which is beneficial to the smooth transition of light, and at the same time balances the spherical aberration and field curvature of the fifth lens, improving the imaging quality of the optical lens.

[0075] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.3 < f7 / f < -1. Meeting the above conditions, the seventh lens has an appropriate negative focal length, which is beneficial to further increasing the imaging area of the optical lens and at the same time balancing various aberrations generated by the front group of lenses, improving the imaging quality of the optical lens.

[0076] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: 1.5 < f8 / f < 1.7. Meeting the above conditions for the eighth lens helps to reasonably collect light, ensure the light passing amount, improve the relative illumination, and enhance the brightness of the optical lens at the image plane.

[0077] In some embodiments, the maximum field of view (FOV) of the optical lens and the true image height (IH) corresponding to the maximum field of view of the optical lens satisfy: 30° / mm < FOV / IH < 32° / mm. Meeting the above conditions can ensure that the optical lens has a large field of view characteristic while meeting the image height requirement, thereby enabling the optical lens to have good optical performance and capturing details of the photographed object well.

[0078] In some embodiments, the true image height (IH) corresponding to the maximum field of view of the optical lens and the f-number (Fno) of the optical lens satisfy: 3.2mm < IH / Fno < 3.6mm. Meeting the above conditions can ensure that the optical lens has a large aperture while maintaining a large image plane, achieving a balance between a large image plane and a large aperture.

[0079] In some embodiments, the maximum field of view (FOV) of the optical lens and the f-number (Fno) of the optical lens satisfy: 105° < FOV / Fno < 110°. Meeting the above conditions is conducive to expanding the field of view of the optical lens and increasing the aperture of the optical lens, achieving the characteristics of an ultra-wide angle and a large aperture for the lens. The realization of the ultra-wide angle characteristic is beneficial for the optical lens to obtain more scene information and meet the requirements of large-range detection. The realization of the large aperture characteristic is beneficial for improving the problem of rapid decline in relative brightness of the edge field of view caused by the wide angle, and thus is also beneficial for obtaining more scene information.

[0080] 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: -0.6 < R5 / R6 < 1.6. Meeting the above conditions, the third lens can balance the system field curvature and avoid deterioration of the edge image quality.

[0081] In some embodiments, the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: -3.2 < (R9 + R10) / (R9 - R10) < 3.6. Meeting the above conditions, by reasonably setting the surface shape of the fifth lens, it is conducive to the smooth transition of light, facilitating the correction of astigmatism and field curvature, improving the imaging quality of the optical lens, and ensuring the stability of the optical system.

[0082] In some embodiments, the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: -0.3 < (R13 + R14) / (R13 - R14) < 0. Meeting the above conditions, reasonably controlling the radii of curvature of the object side surface and the image side surface of the seventh lens is conducive to controlling the shape of the seventh lens, correcting the aberration generated by itself, and improving the imaging quality.

[0083] In some embodiments, the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -2.8 < R8 / f < -2.4. Satisfying the above range can make the image side surface of the fourth lens have an appropriate surface shape, which is beneficial to balancing the astigmatism and field curvature of the optical lens and improving the imaging quality of the optical lens.

[0084] In some embodiments, the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 0 < R12 / f < 0.15. Satisfying the above range can diverge the light rays emitted by the fifth lens, making the light rays in the edge field of view show an upward trend, which is beneficial to the image points on the imaging surface moving away from the optical axis, so as to be beneficial to achieving the effect of matching with a large chip, obtaining a larger picture, effectively eliminating aberration, and improving the resolution ability of the optical lens.

[0085] In some embodiments, the radius of curvature R16 of the image side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -1.5 < R16 / f < -1. Satisfying the above range and reasonably defining the shape of the image side surface of the eighth lens can control the eighth lens to have an appropriate surface shape, which helps to control the light ray trend in the edge field of view and improve the imaging quality of the edge field of view.

[0086] In some embodiments, the focal length f4 of the fourth lens and the focal length f5 of the fifth lens satisfy: -0.15 < f4 / f5 < 0; the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -22 < f5 / f6 < -7; the focal length f6 of the sixth lens and the focal length f7 of the seventh lens satisfy: -2.4 < f6 / f7 < -1.8. Satisfying the above range is beneficial to the smooth transition of light rays, beneficial to correcting the aberration of the optical lens, and improving the imaging quality of the optical lens.

[0087] In some embodiments, the total 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: 0.55 < ∑CT / TTL < 0.65. Satisfying the above conditions can effectively compress the total length of the optical lens, and at the same time is beneficial to the structural design and production process of the optical lens.

[0088] In some embodiments, the spacing CT56 between the fifth lens and the sixth lens on the optical axis, the spacing CT67 between the sixth lens and the seventh lens on the optical axis, the spacing CT78 between the seventh lens and the eighth lens on the optical axis, and the central thickness CT6 of the sixth lens satisfy: 0.45 < (CT56 + CT67 + C78) / CT6 < 0.65. Satisfying the above conditions and reasonably arranging the sizes of the gaps between the fifth lens, the sixth lens, the seventh lens and the eighth lens and the central thickness of the sixth lens is beneficial to realizing the miniaturization characteristics of the system.

[0089] In some embodiments, the central thickness CT3 of the third lens and the edge thickness ET3 of the third lens satisfy: 0.6 < CT3 / ET3 < 1. Meeting the above conditions, by controlling the ratio relationship between the thickness of the third lens on the optical axis and the edge thickness, it is beneficial to balance the aberration generated by the lens itself.

[0090] In some embodiments, the object-side clear aperture sagittal height SAG71 of the seventh lens, the image-side clear aperture sagittal height SAG72 of the seventh lens, and the central thickness CT7 of the seventh lens satisfy: 1.5 < (SAG72 - SAG71) / CT7 < 2.2. Meeting the above conditions can control the surface shape of the object side of the seventh lens, which is beneficial to the manufacture and shaping of the seventh lens, reducing the defective rate. In addition, it can also avoid the surface shape being too curved and complex, making the system field curvature tend to be balanced.

[0091] In some embodiments, the object-side clear aperture sagittal height SAG81 of the eighth lens, the image-side clear aperture sagittal height SAG82 of the eighth lens, and the central thickness CT8 of the eighth lens satisfy: -0.7 < (SAG82 - SAG81) / CT8 < -0.6. Meeting the above conditions, by controlling the relationship between the sagittal height difference between the image side and the object side of the eighth lens and the central thickness of the eighth lens, it is beneficial to correct the coma of the off-axis field, and is beneficial to improving the imaging quality of the off-axis field of the optical lens.

[0092] In some embodiments, the object-side clear aperture DM11 of the first lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.7 < DM11 / IH < 0.9. Meeting the above range can ensure the balance between the front port diameter and the image plane size of the optical lens.

[0093] 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 radian value θ of the maximum half-field angle of the optical lens satisfy: 0.92 < (IH / 2) / (f×θ) < 0.96. Meeting the above conditions can better achieve small distortion and is more beneficial to achieving high resolution.

[0094] In some embodiments, the optical lens satisfies the conditional formula: 17 mm < TTL < 19 mm, 1.8 mm < f < 2.1 mm, 200° < FOV < 210°, 6.4 mm < IH < 6.7 mm, 1.8 < Fno < 2, where TTL represents the total optical length of the optical lens, f represents the effective focal length of the optical lens, FOV represents the maximum field angle of the optical lens, IH represents the image height corresponding to the maximum field angle of the optical lens, and Fno represents the aperture value of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention at least: has a relatively small total optical length; has the characteristics of short focal length and wide angle. The depth of field of a short focal length lens is relatively deep, and both the front and back of the subject can remain relatively clear; has an extremely large field angle, providing a wider shooting field of view for application scenarios such as vehicle-mounted surround-view lenses and capturing more image information; has a relatively large imaging surface, which can be matched with a larger-sized chip to achieve high-definition imaging; has a large aperture and can achieve high-definition imaging even in a complex light environment.

[0095] In some embodiments, the lens material in 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. Additionally, 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 first lens and the fourth lens in the optical lens provided by the present invention can adopt glass materials, and the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens can adopt plastic materials. Adopting a glass-plastic hybrid structure can effectively reduce costs, correct aberrations, reduce the volume, improve the thermal stability performance, and provide an optical lens product with higher cost performance.

[0096] 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 and the fourth lens of the present invention adopt spherical lenses; the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens adopt aspherical lenses.

[0097] In each embodiment 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:

[0098] ;

[0099] 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.

[0100] 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.

[0101] Example 1

[0102] 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, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter G1, and a protective glass G2.

[0103] The first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0104] The second lens L2 has negative optical power, its object side S3 is convex near the optical axis, and its image side S4 is concave.

[0105] The third lens L3 has negative optical power, its object side S5 is concave, and its image side S6 is concave.

[0106] The fourth lens L4 has positive optical power, its object side S7 is convex, and its image side S8 is convex.

[0107] The fifth lens L5 has negative optical power, its object side S9 is convex, and its image side S10 is concave.

[0108] The sixth lens L6 has positive optical power, its object side S11 is convex, and its image side S12 is convex.

[0109] The seventh lens L7 has negative optical power, its object side S13 is concave, and its image side S14 is concave.

[0110] The eighth lens L8 has positive optical power, its object side S15 is convex, and its image side S16 is convex.

[0111] The object-side surface S17 and the image-side surface S18 of filter G1 are both planar.

[0112] The object side S19 and image side S20 of the protective glass G2 are both flat.

[0113] The imaging plane S21 is a plane.

[0114] The first lens L1 and the fourth lens L4 are glass spherical lenses, while the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are plastic aspherical lenses.

[0115] The relevant parameters of each lens in the optical lens of Example 1 are shown in Table 1-1.

[0116] Table 1-1

[0117]

[0118] The surface profile parameters of the aspherical lens in Example 1 are shown in Table 1-2.

[0119] Table 1-2

[0120]

[0121] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown.

[0122] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the 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 -0.05 mm to 0.05 mm, indicating that the optical lens can effectively correct the field curvature.

[0123] Figure 3 The F-Theta distortion curve of Example 1 is shown, which represents the F-Theta distortion of light at different image heights on the imaging plane. The horizontal axis represents the F-Theta distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within -8% to 6%, indicating that the optical lens can effectively correct distortion.

[0124] Figure 4The axial aberration curve of Example 1 is shown, 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 -0.03 mm to 0.03 mm, indicating that the optical lens can correct axial aberration well.

[0125] Figure 5 The diagram shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.555 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -2 μm to 8 μm, indicating that the optical lens can correct chromatic aberration very well.

[0126] Example 2

[0127] Please see Figure 6 The figure shows a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The difference between this embodiment and Embodiment 1 is that: the image side S6 of the third lens L3 is a convex surface; the object side S9 of the fifth lens L5 is a concave surface; the object side S11 of the sixth lens L6 is a concave surface; and the optical parameters such as the radius of curvature and lens 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]

[0134] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0135] Figure 7The field curvature curve of Example 2 is shown, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the 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 -0.05 mm to 0.1 mm, indicating that the optical lens can effectively correct the field curvature.

[0136] Figure 8 The F-Theta distortion curve for Example 2 is shown, representing the F-Theta distortion of light at different image heights on the imaging plane. The horizontal axis represents the F-Theta distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within -6% to 10%, indicating that the optical lens can effectively correct distortion.

[0137] Figure 9 The axial aberration curve of Example 2 is shown, 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 -0.05 mm to 0.02 mm, indicating that the optical lens can correct axial aberration well.

[0138] Figure 10 The diagram shows the transverse chromatic aberration curves for Example 2, representing the chromatic aberration of each wavelength relative to the center wavelength (0.555 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -2 μm to 7 μm, indicating that the optical lens can correct chromatic aberration very well.

[0139] Example 3

[0140] Please see Figure 11 The figure shows a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The difference between this embodiment and Embodiment 1 is that: the object side surface S5 of the third lens L3 is a convex surface; the object side surface S9 of the fifth lens L5 is a concave surface; the image side surface S10 of the fifth lens L5 is a convex surface; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0141] The relevant parameters of each lens in the optical lens of Example 3 are shown in Table 3-1.

[0142] Table 3-1

[0143]

[0144] The surface profile parameters of the aspherical lens in Example 3 are shown in Table 3-2.

[0145] Table 3-2

[0146]

[0147] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0148] Figure 12 The field curvature curve of Example 3 is shown, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the 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 -0.1 mm to 0.1 mm, indicating that the optical lens can effectively correct the field curvature.

[0149] Figure 13 The F-Theta distortion curve for Example 3 is shown, representing the F-Theta distortion of light at different image heights on the imaging plane. The horizontal axis represents the F-Theta distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within -8% to 7%, indicating that the optical lens can effectively correct distortion.

[0150] Figure 14 The axial aberration curve of Example 3 is shown, 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 -0.05 mm to 0.04 mm, indicating that the optical lens can correct axial aberration well.

[0151] Figure 15 The diagram shows the transverse chromatic aberration curves for Example 3, representing the chromatic aberration of each wavelength relative to the center wavelength (0.555 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -4 μm to 8 μm, indicating that the optical lens can correct chromatic aberration very well.

[0152] Example 4

[0153] Please see Figure 16The figure shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The difference between this embodiment and Embodiment 1 is that the image side surface S6 of the third lens L3 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0154] The relevant parameters of each lens in the optical lens of Example 4 are shown in Table 4-1.

[0155] Table 4-1

[0156]

[0157] The surface profile parameters of the aspherical lens in Example 4 are shown in Table 4-2.

[0158] Table 4-2

[0159]

[0160] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens are respectively as follows: Figure 17 , Figure 18 , Figure 19 , Figure 20 As shown.

[0161] Figure 17 The field curvature curve of Example 4 is shown, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the 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 -0.1 mm to 0.05 mm, indicating that the optical lens can effectively correct the field curvature.

[0162] Figure 18 The F-Theta distortion curve for Example 4 is shown, representing the F-Theta distortion of light at different image heights on the imaging plane. The horizontal axis represents the F-Theta distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within -8% to 6%, indicating that the optical lens can effectively correct distortion.

[0163] Figure 19 The axial aberration curve of Example 4 is shown, 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 -0.03 mm to 0.04 mm, indicating that the optical lens can correct axial aberration well.

[0164] Figure 20The diagram shows the transverse chromatic aberration curves for Example 4, representing the chromatic aberration of each wavelength relative to the center wavelength (0.555 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -4 μm to 6 μm, indicating that the optical lens can correct chromatic aberration very well.

[0165] Please refer to Tables 5-1 and 5-2 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, and maximum field of view FOV, as well as the values ​​corresponding to each conditional expression in each embodiment.

[0166] Table 5-1

[0167]

[0168] Table 5-2

[0169]

[0170] In summary, the optical lens provided by the present invention employs 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 large aperture, ultra-wide field of view, high pixel count, and high imaging quality.

[0171] 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.

[0172] 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, eight pieces of lenses in total, characterized in that, In order from the object side to the imaging plane along the optical axis, the optical lens comprises in sequence: a first lens with negative refractive power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a second lens with negative refractive power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a third lens with negative refractive power; a fourth lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a fifth lens with negative refractive power; a sixth lens with positive refractive power, the image side surface of which is a convex surface; a seventh lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface; an eighth lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -50 < f5 / f < -15. The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.5 < TTL / f < 10.

2. The optical lens of claim 1, wherein, The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1.8 < f4 / f < 1.

9.

3. The optical lens of claim 1, wherein, The object side surface curvature radius R1 of the first lens and the image side surface curvature radius R2 of the first lens satisfy: 4.8 < R1 / R2 < 6.

5.

4. The optical lens of claim 1, wherein, The object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: 0 < (R7+R8) / (R7-R8) < 0.

1.

5. The optical lens of claim 1, wherein, The central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 0.1 < CT3 / CT4 < 0.

4.

6. The optical lens of claim 1, wherein, The back focal length BFL of the optical lens and the total optical length TTL of the optical lens satisfy: 0.15 < BFL / TTL < 0.

2.

7. The optical lens of claim 1, wherein, The central thickness CT4 of the fourth lens and the edge thickness ET4 of the fourth lens satisfy: 1.2 < CT4 / ET4 < 1.

4.

8. The optical lens of claim 1, wherein, The object side surface curvature radius R1 of the first lens, the image side surface curvature radius R2 of the first lens, and the central thickness CT1 of the first lens satisfy: 3.5 < R1 / (R2+CT1) < 4.

3.

9. The optical lens of claim 1, wherein, The object side surface half light entrance radius DM11 of the first lens and the image side surface half light entrance radius DM82 of the eighth lens satisfy: 1.8 < DM11 / DM82 < 2.

3.

10. The optical lens of claim 1, wherein, The real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 6 < IH / EPD < 6.5.

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