Optical lens

Abstract

The invention provides an optical lens, which comprises eight lenses from an object side to an imaging surface along an optical axis: a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power, 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; the third lens has negative focal power; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has negative focal power; the sixth lens has positive focal power, and the image side surface of the sixth lens is a convex surface; 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 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. According to the optical lens provided by the invention, the imaging quality of the optical lens is improved through the reasonable configuration of the surface types of the lenses and the reasonable matching of the focal power, so that the lens has one or more advantages of large aperture, ultra-large field angle, high pixel, 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 vehicle optical lenses are playing an increasingly important role in the automobile industry.

[0003] Advanced Driver Assistance System (ADAS) plays an important role in intelligent driving. It collects environmental information through various lenses and 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 cannot meet the needs of users. 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 sequentially includes, along the optical axis from the object side to the imaging surface: a first lens with negative focal power, whose object side surface is convex, and whose image side surface is concave; a second lens with negative focal power, whose object side surface is convex, and whose image side surface is concave; a third lens with negative focal power; a fourth lens with positive focal power, whose object side surface is convex, and whose image side surface is convex; a fifth lens with negative focal power; a sixth lens with positive focal power, whose image side surface is convex; a seventh lens with negative focal power, whose object side surface is concave, and whose image side surface is concave; an eighth lens with positive focal power, whose object side surface is convex, and whose image side surface is convex; The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -50 < f5 / f < -15.

[0006] Further preferably, 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.

[0007] It is further preferred that 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.

[0008] It is further preferred that 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.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] It is further preferred that 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.

[0013] It is further preferred that the object-side surface half diameter DM11 of the first lens and the image-side surface half diameter DM82 of the eighth lens satisfy: 1.8 < DM11 / DM82 < 2.3.

[0014] 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.

[0015] 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 and the like. BRIEF DESCRIPTION OF DRAWINGS

[0016] 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: Figure 1 FIG. 1 is a structure schematic diagram of an optical lens according to an embodiment of the present application.

[0017] Figure 2The field curvature curve of the optical lens in the embodiment 1 of the present application.

[0018] Figure 3 The F-Theta distortion curve of the optical lens in the embodiment 1 of the present application.

[0019] Figure 4 The axial aberration curve of the optical lens in the embodiment 1 of the present application.

[0020] Figure 5 The lateral chromatic aberration curve of the optical lens in the embodiment 1 of the present application.

[0021] Figure 6 The structure schematic diagram of the optical lens in the embodiment 2 of the present application.

[0022] Figure 7 The field curvature curve of the optical lens in the embodiment 2 of the present application.

[0023] Figure 8 The F-Theta distortion curve of the optical lens in the embodiment 2 of the present application.

[0024] Figure 9 The axial aberration curve of the optical lens in the embodiment 2 of the present application.

[0025] Figure 10 The lateral chromatic aberration curve of the optical lens in the embodiment 2 of the present application.

[0026] Figure 11 The structure schematic diagram of the optical lens in the embodiment 3 of the present application.

[0027] Figure 12 The field curvature curve of the optical lens in the embodiment 3 of the present application.

[0028] Figure 13 The F-Theta distortion curve of the optical lens in the embodiment 3 of the present application.

[0029] Figure 14 The axial aberration curve of the optical lens in the embodiment 3 of the present application.

[0030] Figure 15 The lateral chromatic aberration curve of the optical lens in the embodiment 3 of the present application.

[0031] Figure 16 The structure schematic diagram of the optical lens in the embodiment 4 of the present application.

[0032] Figure 17 The field curvature curve of the optical lens in the embodiment 4 of the present application.

[0033] Figure 18 The F-Theta distortion curve of the optical lens in the embodiment 4 of the present application.

[0034] Figure 19 Axial chromatic aberration curve of the optical lens in Embodiment 4 of the present application.

[0035] Figure 20 Axial chromatic aberration curve of the optical lens in Embodiment 4 of the present application.

[0036] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0037] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be noted that the detailed description is only a description of embodiments of the present application and is in no way limiting on the scope of the present application. Throughout the specification, like drawing reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0038] It should be noted that the expressions first, second, third, etc. in the present specification are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0039] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn strictly to scale.

[0040] In this context, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.

[0041] It should also be understood that the use of the terms "have", "has", "having", "include", "includes" or "including" when used in this specification, specifies the presence of stated features, elements, components, and / or steps, but do not preclude the presence or addition of one or more other features, elements, components, steps, and / or groups thereof. Also, the term "comprising" is used herein to mean that the compositions and methods include the recited elements, but not excluding others. Further, when describing the embodiments of the present application, the use of "or" means "and / or" unless otherwise stated.

[0042] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0043] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0044] The optical lens provided by the embodiments of the present application comprises eight lenses, which are sequentially arranged along the optical axis from the object side to the imaging surface and include 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.

[0045] In some embodiments, the first lens can have a negative focal power, the object side surface of which is convex, and the image side surface of which is concave. The second lens can have a negative focal power, the object side surface of which is convex, and the image side surface of which is concave. The third lens can have a negative focal power, the object side surface of which can be concave or convex, and the image side surface of which can be concave or convex. The fourth lens has a positive focal power, the object side surface of which is convex, and the image side surface of which is convex. The fifth lens can have a negative focal power, the object side surface of which can be concave or convex, and the image side surface of which can be concave or convex. The sixth lens can have a positive focal power, the object side surface of which can be concave or convex, and the image side surface of which is convex. The seventh lens can have a negative focal power, the object side surface of which is concave, and the image side surface of which is concave. The eighth lens can have a positive focal power, the object side surface of which is convex, and the image side surface of which is convex.

[0046] In some embodiments, the optical lens can further comprise a diaphragm, which can be located between the fourth lens and the fifth lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging. When the diaphragm is located between the fourth lens and the fifth lens, the correction of the diaphragm aberration is facilitated.

[0047] In some embodiments, the optical lens can further include a filter disposed between the eighth lens and the imaging surface. The filter is configured to filter out interference light to prevent the interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0048] 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. Satisfying the above condition can make the fifth lens have appropriate negative refractive power, which is conducive to increasing the imaging area of the optical lens and improving the imaging quality of the optical lens.

[0049] In some embodiments, 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. Satisfying the above condition can effectively limit the length of the lens, which is conducive to realizing the miniaturization of the optical lens.

[0050] 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. Satisfying the above condition can reasonably set the surface shape of the first lens, enhance the light collecting ability of the first lens, and thus realize an ultra-large field of view.

[0051] 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. Satisfying the above range can make the light trend more stable, correct coma and field curvature, improve the flatness of imaging, and improve the imaging quality of the optical lens.

[0052] 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. Satisfying the above condition can reasonably configure the ratio of the thickness of the third lens on the optical axis and the thickness of the fourth lens on the optical axis, and the third lens and the fourth lens can regulate each other to maintain the miniaturization feature of the optical system.

[0053] In some embodiments, 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. Satisfying the above condition can reasonably configure the ratio of the back focal length of the optical lens and the total optical length of the optical lens, which is conducive to realizing the miniaturization of the optical lens while ensuring that the optical elements have enough space for installation and focusing.

[0054] 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. By satisfying the above condition, by controlling the ratio of the thickness of the fourth lens on the optical axis and the edge thickness, not only can the high-order aberration generated by the optical lens be effectively balanced, but also the field curvature adjustment of the fourth lens can be facilitated, thereby improving the imaging quality of the optical lens.

[0055] In some embodiments, the object side surface radius of curvature R1 of the first lens, the image side surface radius of curvature R2 of the first lens, and the central thickness CT1 of the first lens satisfy: 3.5 < R1 / (R2+CT1) < 4.3. By satisfying the above range, the correction difficulty of the edge field distortion can be reduced, and the distortion can be controlled within a reasonable range.

[0056] In some embodiments, the object side surface diameter DM11 of the first lens and the image side surface diameter DM82 of the eighth lens satisfy: 1.8 < DM11 / DM82 < 2.3. By satisfying the above range, by reasonably setting the ratio of the diameters of the first and last lenses, the lens can have a smaller head size while having a larger imaging surface, which can better balance miniaturization and high pixels.

[0057] In some embodiments, 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. By satisfying the above range, the optical lens can satisfy the edge field of view with sufficient image surface brightness while satisfying the large image surface, thereby preventing the occurrence of dark corner phenomenon and improving the imaging quality.

[0058] In some embodiments, the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens, and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 55° < (f x FOV) / IH < 65°. By satisfying the above condition, by reasonably limiting the relationship between the focal length, the field angle, and the image height of the optical lens, the balance between the large field angle of the optical lens and the large target surface imaging can be achieved, thereby better meeting the use requirements of the vehicle-mounted surround view camera.

[0059] In some embodiments, the real 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. By satisfying the above condition, a super large field angle and imaging range can be achieved, which can ensure the depth of field of the optical lens while realizing the large image surface characteristics, thereby improving the imaging quality of the optical system.

[0060] In some embodiments, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 2.6 < TTL / IH < 2.9. Satisfying the above condition, the miniaturization of the lens can be better realized, and meanwhile, the lens has a larger image surface under the condition of the same total length, which can match a larger imaging chip to realize high-definition imaging.

[0061] 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. Satisfying the above condition, the first lens has a proper negative focal length, which is conducive to expanding the field of view angle of the optical lens.

[0062] 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. Satisfying the above condition, the second lens also adopts a negative lens, which can further diverge light rays and improve the field of view angle of the imaging system.

[0063] 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. Satisfying the above condition, the fourth lens converges the incident light rays at the front end, which is conducive to correcting the aberration and edge field distortion caused by the front lens group, so that the lens has smaller distortion and can provide high-definition imaging effect.

[0064] 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. Satisfying the above condition, the sixth lens has a proper positive focal power, which is conducive to smooth transition of light rays and balances the spherical aberration and field curvature of the fifth lens, thereby improving the imaging quality of the optical lens.

[0065] 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. Satisfying the above condition, the seventh lens has a proper negative focal length, which is conducive to further increasing the imaging area of the optical lens and balancing various aberrations generated by the front lens group, thereby improving the imaging quality of the optical lens.

[0066] 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. Satisfying the above condition, the eighth lens helps to reasonably collect light, ensures the light flux, improves the relative luminance, and thus improves the brightness at the image surface of the optical lens.

[0067] In some embodiments, the maximum field of view FOV of the optical lens and the real image height IH corresponding to the maximum field of view FOV of the optical lens satisfy: 30° / mm<FOV / IH<32° / mm. By satisfying the above condition, the optical lens has a large field of view, and the optical lens has good optical performance and can capture details of the object well.

[0068] In some embodiments, the real image height IH corresponding to the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 3.2mm<IH / Fno<3.6mm. By satisfying the above condition, the optical lens has a large image surface and a large aperture, and the balance between the large image surface and the large aperture is achieved.

[0069] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 105°<FOV / Fno<110°. By satisfying the above condition, the field of view of the optical lens is expanded, and the aperture of the optical lens is increased, and the characteristics of the super wide angle and the large aperture of the lens are achieved. The realization of the super wide angle characteristic is conducive to obtaining more scene information and meeting the demand of wide range detection, and the realization of the large aperture characteristic is conducive to improving the problem of rapid decline of relative brightness at the edge of the field of view caused by the wide angle, thereby also conducive to obtaining more scene information.

[0070] In some embodiments, 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: -0.6<R5 / R6<1.6. By satisfying the above condition, the third lens can balance the system field curvature, and the edge image quality degradation is avoided.

[0071] In some embodiments, the curvature radius R9 of the object side surface of the fifth lens and the curvature radius R10 of the image side surface of the fifth lens satisfy: -3.2<(R9+R10) / (R9-R10)<3.6. By satisfying the above condition, by reasonably setting the surface type of the fifth lens, the light rays are smoothly transitioned, the correction of the astigmatism and the field curvature is facilitated, the imaging quality of the optical lens is improved, and the stability of the optical system is ensured.

[0072] In some embodiments, the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: -0.3<(R13+R14) / (R13-R14)<0. By satisfying the above condition, the curvature radii of the object side surface and the image side surface of the seventh lens are reasonably controlled, thereby facilitating the control of the shape of the seventh lens, the correction of the aberration generated by itself, and the improvement of the imaging quality.

[0073] In some embodiments, the image side curvature radius R8 of the fourth lens element and the effective focal length f of the optical lens satisfy: -2.8 <R8 / f<-2.4。满足上述范围,可以使第四透镜像侧面具有适当的面型,有利于平衡光学镜头的像散和场曲,提升光学镜头的成像品质。

[0074] In some embodiments, the image side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: <R12 / f<0.15。满足上述范围,可以将第五透镜出射的光线进行发散,使边缘视场的光线呈上升趋势,有利于成像面上的像点远离光轴,以有利于实现与大芯片匹配的效果,获得更大的画面,可以有效消除像差,提高光学镜头的解像能力。

[0075] In some embodiments, the image side curvature radius R16 of the eighth lens and the effective focal length f of the optical lens satisfy: -1.5 <R16 / f<-1。满足上述范围,合理限定第八透镜像侧面的形状,能够控制第八透镜具有适当的面型,有助于控制边缘视场的光线走势,提高边缘视场的成像质量。

[0076] 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;第五透镜的焦距f5与第六透镜的焦距f6满足:-22<f5 / f6<-7;第六透镜的焦距f6与第七透镜的焦距f7满足:-2.4<f6 / f7<-1.8。满足上述范围,有利于光线平稳过渡,有利于校正光学镜头的像差,提升光学镜头的成像品质。

[0077] In some embodiments, the total optical length TTL of the optical lens and the sum of the center thicknesses of the first through eighth lenses along the optical axis, ΣCT, satisfy the following condition: 0.55 < ΣCT / TTL < 0.65. Meeting this condition effectively reduces the total length of the optical lens and facilitates its structural design and production process.

[0078] In some embodiments, the distance CT56 between the fifth and sixth lenses, the distance CT67 between the sixth and seventh lenses, the distance CT78 between the seventh and eighth lenses, and the center thickness CT6 of the sixth lens satisfy the following conditions: 0.45 < (CT56 + CT67 + CT78) / CT6 < 0.65. Meeting these conditions and properly arranging the gaps between the fifth, sixth, seventh, and eighth lenses, as well as the center thickness of the sixth lens, facilitates system miniaturization.

[0079] 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. By satisfying the above condition, by controlling the ratio of the thickness of the third lens on the optical axis and the edge thickness, the aberration generated by the lens itself can be balanced.

[0080] In some embodiments, the object-side surface semi-aperture radius sagittal height SAG71 of the seventh lens, the image-side surface semi-aperture radius sagittal height SAG72 of the seventh lens, and the central thickness CT7 of the seventh lens satisfy: 1.5 < (SAG72-SAG71) / CT7 < 2.2. By satisfying the above condition, the surface shape of the object-side surface of the seventh lens can be controlled, which is beneficial for the manufacturing and forming of the seventh lens and reduces the defective rate. In addition, the surface shape is also prevented from being too curved and complex, so that the system field curvature tends to be balanced.

[0081] In some embodiments, the object-side surface semi-aperture radius sagittal height SAG81 of the eighth lens, the image-side surface semi-aperture radius sagittal height SAG82 of the eighth lens, and the central thickness CT8 of the eighth lens satisfy: -0.7 < (SAG82-SAG81) / CT8 < -0.6. By satisfying the above condition, by controlling the height difference between the sagittal heights of the image-side surface and the object-side surface of the eighth lens and the central thickness of the eighth lens, the coma of the off-axis field can be corrected, and the imaging quality of the optical lens off-axis field can be improved.

[0082] In some embodiments, the object-side surface semi-aperture radius DM11 of the first lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.7 < DM11 / IH < 0.9. By satisfying the above range, the balance of the front aperture of the optical lens and the image size can be ensured.

[0083] In some embodiments, the real 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 x θ) < 0.96. By satisfying the above condition, small distortion can be better achieved, and high resolution can be more beneficially achieved.

[0084] In some embodiments, the optical lens satisfies the condition formula: 17mm < TTL < 19mm, 1.8mm < f < 2.1mm, 200° < FOV < 210°, 6.4mm < IH < 6.7mm, 1.8 < Fno < 2, wherein 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 of view angle of the optical lens, IH represents the image height corresponding to the maximum field of view angle of the optical lens, and Fno represents the aperture value of the optical lens. Satisfying the above condition indicates that the optical lens provided in the embodiments of the present application at least: has a small total optical length; has the characteristics of short focal length and wide angle, the depth of field of the short focal length lens is relatively deep, and the subject in front and back can remain relatively clear; has a super large field of view angle, which provides a wider shooting field of view for the application scenarios such as vehicle-mounted surround view lens, and takes more image information; has a larger imaging surface, which can match a larger size chip to realize high-definition imaging; has a large aperture, which can realize high-definition imaging even in a complex light environment.

[0085] In some embodiments, the lens material in the optical lens provided by the present application can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. When the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristics of the glass itself. The first lens and the fourth lens in the optical lens provided by the present application can be made of glass, and the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens can be made of plastic. The use of glass-plastic hybrid structure can effectively reduce the cost, correct the aberration, reduce the volume, improve the thermal stability and provide an optical lens product with higher cost performance.

[0086] 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 be a spherical lens or an aspherical lens. 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 application are spherical lenses, and the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are aspherical lenses.

[0087] In various embodiments of the present application, when the lens is an aspherical lens, the shape of each aspherical surface of the optical lens satisfies the following equation: ; wherein z is the distance of the curved surface from the vertex of the curved surface in the direction of the optical axis, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the quadratic surface coefficient, and B, C, D, E, F, G and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order and sixteenth-order surface coefficients, respectively.

[0088] The application will be further described in the following embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different, and the specific differences can be seen from the parameter table of each embodiment. The following embodiments are only preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments only, and any changes, substitutions, combinations or simplifications made without departing from the innovative points of the application should be regarded as equivalent replacement methods, and are included in the protection scope of the application.

[0089] Embodiment 1 Please refer to Figure 1 , which is a structural schematic diagram of the optical lens 100 provided in the embodiment 1 of the application, which includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a stop 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.

[0090] The first lens L1 has a negative focal power, the object side surface S1 is a convex surface, and the image side surface S2 is a concave surface; The second lens L2 has a negative focal power, the object side surface S3 is a convex surface at the near optical axis, and the image side surface S4 is a concave surface; The third lens L3 has a negative focal power, the object side surface S5 is a concave surface, and the image side surface S6 is a concave surface; The fourth lens L4 has a positive focal power, the object side surface S7 is a convex surface, and the image side surface S8 is a convex surface; The fifth lens L5 has a negative focal power, the object side surface S9 is a convex surface, and the image side surface S10 is a concave surface; The sixth lens L6 has a positive focal power, the object side surface S11 is a convex surface, and the image side surface S12 is a convex surface; The seventh lens L7 has a negative focal power, the object side surface S13 is a concave surface, and the image side surface S14 is a concave surface; The eighth lens L8 has a positive focal power, the object side surface S15 is a convex surface, and the image side surface S16 is a convex surface; The object side surface S17 and the image side surface S18 of the filter G1 are both flat surfaces; The object side surface S19 and the image side surface S20 of the protective glass G2 are both flat surfaces; The imaging surface S21 is a flat surface.

[0091] The first lens L1 and the fourth lens L4 are glass spherical lenses, and 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.

[0092] The related parameters of each lens in the optical lens in Embodiment 1 are shown in Table 1-1.

[0093] Table 1-1 The surface type parameters of the aspherical lens of the optical lens in Embodiment 1 are shown in Table 1-2.

[0094] Table 1-2 In this embodiment, the field curvature curve, the F-Theta distortion curve, the axial aberration curve, and the transverse chromatic aberration curve of the optical lens are shown in FIGS. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5

[0095] Figure 2 The field curvature curve of Embodiment 1 is shown, which represents the curvature of light rays on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.05 mm~0.05 mm, which shows that the optical lens can well correct the field curvature.

[0096] Figure 3 The F-Theta distortion curve of Embodiment 1 is shown, which represents the F-Theta distortion of light rays at different image heights on the imaging surface, the horizontal axis represents the F-Theta distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within -8%~6%, which shows that the optical lens can well correct the distortion.

[0097] Figure 4 The axial aberration curve of Embodiment 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging surface, 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 offset of the axial aberration is controlled within -0.03 mm~0.03 mm, which shows that the optical lens can well correct the axial aberration.

[0098] Figure 5 The transverse chromatic aberration curve of Embodiment 1 is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.555 μm) at different image heights on the imaging surface, the horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. As can be seen from the figure, the transverse chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -2 μm~8 μm, which shows that the optical lens can well correct the chromatic aberration.

[0099] Embodiment 2​ Please refer to Figure 6 , which is a structural schematic diagram of the optical lens 200 provided in Embodiment 2 of the present application. Compared with Embodiment 1, the difference lies in that the image side surface S6 of the third lens L3 is a convex surface; the object side surface S9 of the fifth lens L5 is a concave surface; the object side surface S11 of the sixth lens L6 is a concave surface; and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0100] The related parameters of each lens in the optical lens in Embodiment 2 are shown in Table 2-1.

[0101] Table 2-1 The surface type parameters of the aspheric lens of the optical lens in Embodiment 2 are shown in Table 2-2.

[0102] Table 2-2 In this embodiment, the field curvature curve, the F-Theta distortion curve, the axial aberration curve and the transverse aberration curve of the optical lens are shown in Figure 7 , Figure 8 , Figure 9 , Figure 10 respectively.

[0103] Figure 7 The field curvature curve of Embodiment 2 is shown, which represents the curvature degree of light rays on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and the sagittal image surface is controlled within-0.05mm~0.1mm, which shows that the optical lens can well correct the field curvature.

[0104] Figure 8 The F-Theta distortion curve of Embodiment 2 is shown, which represents the F-Theta distortion of light rays at different image heights on the imaging surface, the horizontal axis represents the F-Theta distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within-6%~10%, which shows that the optical lens can well correct the distortion.

[0105] Figure 9 The axial aberration curve of Embodiment 2 is shown, which represents the aberration of each wavelength on the optical axis at the imaging surface, 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 offset of the axial aberration is controlled within-0.05mm~0.02mm, which shows that the optical lens can well correct the axial aberration.

[0106] Figure 10The axial chromatic aberration curve of the optical lens of embodiment 2 is shown in the figure, which represents the chromatic aberration of each wavelength at different image heights on the imaging surface relative to the central wavelength (0.555 μm), the horizontal axis represents the axial chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the figure, the axial chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -2 μm ~ 7 μm, which shows that the optical lens can correct chromatic aberration very well.

[0107] Embodiment 3 Please refer to Figure 11 , which is a structural schematic diagram of the optical lens 300 provided in embodiment 3 of the present application. Compared with embodiment 1, the difference is that the object side S5 of the third lens L3 is a convex surface; the object side S9 of the fifth lens L5 is a concave surface; the image side S10 of the fifth lens L5 is a convex surface; and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0108] The related parameters of each lens in the optical lens of embodiment 3 are shown in Table 3-1.

[0109] Table 3-1 The surface type parameters of the aspherical lens of the optical lens in embodiment 3 are shown in Table 3-2.

[0110] Table 3-2 In this embodiment, the field curvature curve, the F-Theta distortion curve, the axial aberration curve, and the axial chromatic aberration curve of the optical lens are shown in Figure 12 , Figure 13 , Figure 14 , Figure 15 respectively.

[0111] Figure 12 The field curvature curve of embodiment 3 is shown in the figure, which represents the bending degree of light rays on the meridional image surface and the sagittal image surface, 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 image surface and the sagittal image surface is controlled within -0.1 mm ~ 0.1 mm, which shows that the optical lens can correct the field curvature well.

[0112] Figure 13 The F-Theta distortion curve of embodiment 3 is shown in the figure, which represents the F-Theta distortion of light rays at different image heights on the imaging surface, 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% ~ 7%, which shows that the optical lens can correct the distortion well.

[0113] Figure 14 The axial aberration curve of the optical lens of embodiment 3 is shown, which represents the aberration of the optical axis at the imaging surface at each wavelength, 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 shift of the axial aberration is controlled within -0.05mm~0.04mm, which shows that the optical lens can correct the axial aberration well.

[0114] Figure 15 The axial aberration curve of the optical lens of embodiment 3 is shown, which represents the aberration of the optical axis at the imaging surface at each wavelength, 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 shift of the axial aberration is controlled within -0.05mm~0.04mm, which shows that the optical lens can correct the axial aberration well.

[0115] Embodiment 4 Please refer to Figure 16 , which is a structural schematic diagram of the optical lens 400 provided in embodiment 4 of the present application. Compared with embodiment 1, the difference between the two embodiments is that the image side S6 of the third lens L3 is a convex surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0116] The related parameters of each lens in the optical lens in embodiment 4 are shown in Table 4-1.

[0117] Table 4-1 The surface type parameters of the aspherical lens of the optical lens in embodiment 4 are shown in Table 4-2.

[0118] Table 4-2 In this embodiment, the field curvature curve, the F-Theta distortion curve, the axial aberration curve, and the axial aberration curve of the optical lens are shown in Figure 17 , Figure 18 , Figure 19 , Figure 20 respectively.

[0119] Figure 17 The field curvature curve of embodiment 4 is shown, which represents the curvature of the meridional image surface and the sagittal image surface, the horizontal axis represents the shift (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.1mm~0.05mm, which shows that the optical lens can correct the field curvature well.

[0120] Figure 18The F-Theta distortion curve of embodiment 4 is shown, which represents the F-Theta distortion of light rays 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%~6%, which shows that the optical lens can well correct the distortion.

[0121] Figure 19 The axial aberration curve of embodiment 4 is shown, which represents the axial 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 offset of the axial aberration is controlled within -0.03mm~0.04mm, which shows that the optical lens can better correct the axial aberration.

[0122] Figure 20 The sagittal chromatic aberration curve of embodiment 4 is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.555μm) at different image heights on the imaging plane. The horizontal axis represents the sagittal chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the figure, the sagittal chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -4μm~6μm, which shows that the optical lens can very well correct the chromatic aberration.

[0123] Please refer to Table 5-1 and Table 5-2, which are the optical properties corresponding to each of the above embodiments, including the effective focal length f, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view, the chief ray angle CRA at the maximum image height, the maximum field of view FOV, and the numerical values corresponding to each condition in each embodiment.

[0124] Table 5-1 Table 5-2 In summary of the above embodiments, the optical lens provided by the present application adopts eight lenses with specific optical power, 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. The lens has one or more advantages such as large aperture, ultra-large field of view, high pixel, high imaging quality, etc.

[0125] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present 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 can be combined in any one or more embodiments or examples in a suitable manner.

[0126] The above-described embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but cannot be understood as a limitation on the patent scope of the present application. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An optical lens, comprising eight lenses, characterized in that: Along the optical axis from the object side to the imaging surface, it includes: a first lens having negative optical power, wherein the object-side surface is convex and the image-side surface is concave; a second lens having negative optical power, the object-side surface of which is convex and the image-side surface of which is concave; a third lens having negative optical power; a fourth lens element having positive refractive power, whose object-side surface is convex and whose image-side surface is convex; a fifth lens having negative optical power; a sixth lens element having positive refractive power and a convex image-side surface; a seventh lens element having negative optical power, whose object-side surface and image-side surface are concave; an eighth lens element having positive refractive power, whose object-side surface is convex and whose image-side surface is convex; The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: <f5 / f<-15。 2. The optical lens according to claim 1, wherein: 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。 3. The optical lens according to claim 1, wherein: The object side curvature radius R1 of the first lens and the image side curvature radius R2 of the first lens satisfy: 4.8 <R1 / R2<6.5。 4. The optical lens according to claim 1, wherein: The object-side curvature radius R7 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy: 0<(R7+R8) / (R7-R8)<0.

1.

5. The optical lens according to claim 1, wherein: The center thickness CT3 of the third lens and the center thickness CT4 of the fourth lens satisfy: 0.1 <CT3 / CT4<0.4。 6. The optical lens according to claim 1, wherein: The back focal length BFL of the optical lens and the total optical length TTL of the optical lens meet the following conditions: 0.15 <BFL / TTL<0.2。 7. The optical lens according to claim 1, wherein: The center 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 according to claim 1, wherein: The object side curvature radius R1 of the first lens, the image side curvature radius R2 of the first lens and the center thickness CT1 of the first lens meet the following conditions: 3.5 <R1 / (R2+CT1)<4.3。 9. The optical lens according to claim 1, wherein: The object side light semi-aperture DM11 of the first lens and the image side light semi-aperture DM82 of the eighth lens meet the following conditions: 1.8 <DM11 / DM82<2.3。 10. The optical lens according to claim 1, wherein: 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: <IH / EPD<6.5。

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