Optical lens

Abstract

The application provides an optical lens, which comprises seven lenses in sequence along an optical axis from an object side to an imaging surface, and the seven 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 concave surface, and the image side surface of the second lens is a convex surface; a third lens with positive optical power, wherein the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; 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, wherein the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a concave surface; a sixth lens with positive optical power, wherein the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface; and a seventh lens with negative optical power, wherein the object side surface of the seventh lens is a concave surface. The optical lens provided by the application has one or more advantages, such as a large aperture, a large field of view, good resolving power, high illumination, high imaging quality and the like, through specific surface shape matching and reasonable optical power distribution.

Description

TECHNICAL FIELD

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

[0002] With the increasing demand for driving experience, vehicle application type optical lenses are increasingly used in intelligent driving, and the status of vehicle optical lenses in the automotive industry is continuously improving.

[0003] Advanced Driver Assistance System (ADAS) plays an important role in intelligent driving, which collects environmental information through various lenses combined with sensors to ensure the safety of drivers. In addition to the requirements of optical lenses for the existing ADAS system, such as light and thin shape, high pixel, high resolution and other characteristics, the optical lens is also required to clearly image under low illumination conditions, so 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 excellent imaging quality.

[0005] The technical scheme adopted by the present application is:

[0006] An optical lens, a total of seven lenses, including:

[0007] The first lens with negative focal power, the object side surface is convex, and the image side surface is concave;

[0008] The second lens with negative focal power, the object side surface is concave, and the image side surface is convex;

[0009] The third lens with positive focal power, the object side surface is convex, and the image side surface is convex;

[0010] The fourth lens with positive focal power, the object side surface is convex, and the image side surface is convex;

[0011] The fifth lens with negative focal power, the object side surface is convex, and the image side surface is concave;

[0012] The sixth lens with positive focal power, the object side surface is convex, and the image side surface is convex;

[0013] The seventh lens with negative focal power, the object side surface is concave;

[0014] The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -75 < f2 / f < -20; the half radius sagittal height SAG41 of the object side surface of the fourth lens, the half radius sagittal height SAG42 of the image side surface of the fourth lens, and the central thickness CT4 of the fourth lens satisfy: -0.4 < (SAG42-SAG41) / CT4 < -0.25.

[0015] Further preferably, the combined focal length f56 of the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 3.5 < f56 / f < 7.2.

[0016] Further preferably, the combined focal length f123 of the first lens, the second lens, and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: 0.45 < f123 / f4567 < 0.55.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.3 < f6 / f < 1.4.

[0018] Further preferably, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 75° < FOV / Fno < 100°.

[0019] Further preferably, the real image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.2 < IH / EPD < 4.2.

[0020] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 7.5 < TTL / f < 8.

[0021] Further preferably, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis satisfy: 0.55 < ∑CT / TTL < 0.65.

[0022] Further preferably, the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: 0.05 < f1 / f7 < 0.4.

[0023] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 4.4 < f4 / f < 5.5.

[0024] The optical lens provided by the application adopts seven lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens is improved, the aberration is reduced, and the imaging quality of the optical lens is improved, so that the lens has one or more advantages of large aperture, large field of view, good resolving power, high illumination, high imaging quality and the like. 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, including the cooperation of the following drawings, in which:

[0026] Figure 1 It is a structure schematic diagram of the optical lens in the embodiment 1 of the present application.

[0027] Figure 2 It is a field curvature curve diagram of the optical lens in the embodiment 1 of the present application.

[0028] Figure 3 It is an F-Theta distortion curve diagram of the optical lens in the embodiment 1 of the present application.

[0029] Figure 4 It is an axial aberration curve diagram of the optical lens in the embodiment 1 of the present application.

[0030] Figure 5 It is a lateral chromatic aberration curve diagram of the optical lens in the embodiment 1 of the present application.

[0031] Figure 6 It is an MTF curve diagram of the optical lens in the embodiment 1 of the present application.

[0032] Figure 7 It is a relative illumination curve diagram of the optical lens in the embodiment 1 of the present application.

[0033] Figure 8 It is a structure schematic diagram of the optical lens in the embodiment 2 of the present application.

[0034] Figure 9 It is a field curvature curve diagram of the optical lens in the embodiment 2 of the present application.

[0035] Figure 10 It is an F-Theta distortion curve diagram of the optical lens in the embodiment 2 of the present application.

[0036] Figure 11 It is an axial aberration curve diagram of the optical lens in the embodiment 2 of the present application.

[0037] Figure 12 It is a lateral chromatic aberration curve diagram of the optical lens in the embodiment 2 of the present application.

[0038] Figure 13 It is an MTF curve diagram of the optical lens in the embodiment 2 of the present application.

[0039] Figure 14 The relative illumination curve of the optical lens in Embodiment 2 of the present application.

[0040] Figure 15 The structural schematic diagram of the optical lens in Embodiment 3 of the present application.

[0041] Figure 16 The field curvature curve of the optical lens in Embodiment 3 of the present application.

[0042] Figure 17 The F-Theta distortion curve of the optical lens in Embodiment 3 of the present application.

[0043] Figure 18 The axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0044] Figure 19 The lateral chromatic aberration curve of the optical lens in Embodiment 3 of the present application.

[0045] Figure 20 The MTF curve of the optical lens in Embodiment 3 of the present application.

[0046] Figure 21 The relative illumination curve of the optical lens in Embodiment 3 of the present application.

[0047] Figure 22 The structural schematic diagram of the optical lens in Embodiment 4 of the present application.

[0048] Figure 23 The field curvature curve of the optical lens in Embodiment 4 of the present application.

[0049] Figure 24 The F-Theta distortion curve of the optical lens in Embodiment 4 of the present application.

[0050] Figure 25 The axial aberration curve of the optical lens in Embodiment 4 of the present application.

[0051] Figure 26 The lateral chromatic aberration curve of the optical lens in Embodiment 4 of the present application.

[0052] Figure 27 The MTF curve of the optical lens in Embodiment 4 of the present application.

[0053] Figure 28 The relative illumination curve of the optical lens in Embodiment 4 of the present application.

[0054] The following detailed description will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0055] 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 these details are merely exemplary of the embodiments of the present application and are intended to provide a more detailed description of the application as claimed. Throughout the specification, like drawing reference numbers will be understood to refer to like parts throughout the specification and the claims. The expression "and / or" encompasses any and all combinations of one or more of the associated listed items.

[0056] It is noted that, in this specification, the terms first, second, third, etc. are merely used to distinguish one feature from another, and do not denote any limitation on the features. Thus, the first lens discussed below can also be called the second lens or the third lens without departing from the teachings of the present application.

[0057] 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.

[0058] In this specification, 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 called the object side surface of the lens, and the surface of each lens closest to the image plane is called the image side surface of the lens.

[0059] It is also to be understood that the use of the terms "include", "includes", "including", "comprise", "comprises", "comprising", "have", "has", "having", or "contains" or "containing", when used in this specification, means that there are other items not listed which are also included in the statement, but do not exclude the presence or addition of one or more other features, elements, components, and / or a combination thereof. In addition, when expressions such as "at least one of" appear after a list of items, it modifies the entire list of items and does not modify the individual elements of the list. Furthermore, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the term "exemplary" is intended to mean an example or an illustration.

[0060] 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.

[0061] It should be noted that the embodiments in the present application and the features in the embodiments 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 combination with the embodiments.

[0062] The optical lens provided by the embodiment of the present application is composed of seven lenses, which are sequentially arranged along the optical axis from the object side to the imaging surface as the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens.

[0063] In some embodiments, the first lens can have a negative focal length, the object side surface of which is a convex surface, and the image side surface of which is a concave surface. The second lens can have a negative focal length, the object side surface of which is a concave surface, and the image side surface of which is a convex surface. The third lens can have a positive focal length, the object side surface of which is a convex surface, and the image side surface of which is a convex surface. The fourth lens can have a positive focal length, the object side surface of which is a convex surface, and the image side surface of which is a convex surface. The fifth lens can have a negative focal length, the object side surface of which is a convex surface, and the image side surface of which is a concave surface. The sixth lens can have a positive focal length, the object side surface of which is a convex surface, and the image side surface of which is a convex surface. The seventh lens can have a negative focal length, the object side surface of which is a concave surface, and the image side surface of which can be a concave surface or a convex surface.

[0064] In some embodiments, the optical lens can further include a diaphragm, which can be located between the third lens and the fourth lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging. In addition, when the diaphragm is located between the third lens and the fourth lens, the diaphragm can reasonably distribute the functions of the first lens to the seventh lens, for example, the first lens, the second lens and the third lens can be used to receive light to a greater extent, and the fourth lens to the seventh lens can be used for the function of correcting aberration, which is conducive to balancing the structure of the entire optical system. In addition, when the diaphragm is located between the third lens and the fourth lens, the diaphragm aberration correction is facilitated.

[0065] In some embodiments, the optical lens can further include a filter, which can be arranged between the seventh lens and the imaging surface. The filter is used to filter out interference light to prevent interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0066] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -1.8 < f1 / f < -1.6. Satisfying the above condition, the first lens has an appropriate negative focal length, which is conducive to expanding the field of view of the optical lens.

[0067] In some embodiments, the combined focal length f56 of the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 3.5 < f56 / f < 7.2. Satisfying the above condition, it is helpful for more light to enter the cemented lens smoothly and for improving the illumination.

[0068] In some embodiments, a combined focal length f123 of the first lens, the second lens and the third lens and a combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: 0.45 < f123 / f4567 < 0.55. Satisfying the above range can reasonably allocate the light power ratio of the front and rear lens groups of the diaphragm, increase the relative luminance of the lens, and improve the imaging quality of the lens.

[0069] In some embodiments, an effective focal length f of the optical lens and a focal length f5 of the fifth lens satisfy: -1.9 < f5 / f < -1.3; and the effective focal length f of the optical lens and a focal length f6 of the sixth lens satisfy: 1.3 < f6 / f < 1.4. Satisfying the above conditions, the fifth lens and the sixth lens are cemented to form a double-cemented lens, the fifth lens and the sixth lens can have opposite positive and negative optical powers, so that various aberrations of the optical lens are sufficiently corrected, the resolution can be improved, and high resolution is achieved. At the same time, the use of the cemented part is conducive to reducing the tolerance sensitivity of the lens to tilt / offset during assembly, improving the resolution stability, and further improving the system performance.

[0070] In some embodiments, a maximum field of view FOV of the optical lens and an aperture value Fno of the optical lens satisfy: 75° < FOV / Fno < 100°. Satisfying the above conditions is conducive to improving the light intake of the lens, so that the lens can also achieve high-definition imaging in a dark environment.

[0071] In some embodiments, a real image height IH corresponding to a maximum field of view of the optical lens and an entrance pupil diameter EPD of the optical lens satisfy: 3.2 < IH / EPD < 4.2. Satisfying the above range makes the optical lens meet the large image surface while also meeting the sufficient image surface brightness of the edge field of view, preventing the occurrence of dark corner phenomenon, thereby improving the imaging quality.

[0072] In some embodiments, an optical total length TTL of the optical lens and an effective focal length f of the optical lens satisfy: 7.5 < TTL / f < 8. Satisfying the above conditions can effectively limit the length of the lens, which is conducive to realizing the miniaturization of the optical lens.

[0073] In some embodiments, an optical total length TTL of the optical lens and a sum ∑CT of the central thicknesses of the first lens to the seventh 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.

[0074] In some embodiments, the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: 0.05 < f1 / f7 < 0.4. By satisfying the above condition, by reasonably setting the focal length relationship of the first and last lenses in the lens, while ensuring that as many light rays as possible enter the system, the area of the light rays entering the imaging surface is increased, which is conducive to realizing large image surface imaging of the lens, while increasing the amount of light entering, improving the relative luminance of the system.

[0075] In some embodiments, the half-surface sagittal height SAG41 of the object side of the fourth lens, the half-surface sagittal height SAG42 of the image side of the fourth lens, and the central thickness CT4 of the fourth lens satisfy: -0.4 < (SAG42-SAG41) / CT4 < -0.25. By satisfying the above condition, by controlling the height difference between the image side and the object side of the fourth lens and the central thickness of the fourth lens, the shape of the fourth lens can be constrained, which is conducive to the design and processing of the fourth lens structure, conducive to correcting the aberration of each field of view, and conducive to improving the imaging quality of the optical lens.

[0076] In some embodiments, the back focal length BFL of the optical lens and the total optical length TTL of the optical lens satisfy: 0.09 < BFL / TTL < 0.17. By satisfying the above condition, by reasonably configuring the ratio of the back focal length of the optical lens to the total optical length of the optical lens, the short back focal length of the optical lens is realized, and in the case of ensuring sufficient space for optical element installation and focusing, the miniaturization of the optical lens is realized.

[0077] In some embodiments, the maximum field of view FOV of the optical lens, the effective focal length f of the optical lens, and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 60° < (f x FOV) / IH < 65°. By satisfying the above condition, by reasonably limiting the relationship between the focal length, the field of view angle, and the image height of the optical lens, the balance between the large field of view angle and the large target surface imaging of the optical lens is realized, and the use requirements of the vehicle-mounted camera are better met.

[0078] In some embodiments, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 2.1 < IH / f < 2.3. By satisfying the above condition, a larger field of view angle and imaging range can be realized, the large image surface characteristic can be realized while ensuring the depth of field of the optical lens, and thus the imaging quality of the optical system is improved.

[0079] 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 of the optical lens satisfy: 3.2 < TTL / IH < 3.7. By satisfying the above condition, the miniaturization of the lens can be better realized, and at the same total length, the lens has a larger image surface, which can match a larger size imaging chip to realize high-definition imaging.

[0080] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -75 < f2 / f < -20. With the above condition satisfied, the second lens also adopts a negative lens, which can further diverge the light rays and improve the field angle of the imaging system.

[0081] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 2.5 < f3 / f < 3.2; and the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 4.4 < f4 / f < 5.5. With the above conditions satisfied, the third and fourth lenses converge the front-end incident light rays, which is beneficial to correct the aberration and edge field distortion caused by the front-end lens group, so that the lens has smaller distortion and can provide high-definition imaging effect.

[0082] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -28 < f7 / f < -4.2. With the above condition satisfied, the seventh lens has an appropriate negative focal length, which is beneficial to further increase the imaging area of the optical lens, while balancing various aberrations generated by the front group of lenses, and improving the imaging quality of the optical lens.

[0083] In some embodiments, 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: 15° / mm < FOV / IH < 16° / mm. With the above condition satisfied, the optical lens has a large field angle under the premise of meeting the image height requirement, so that the optical lens has good optical performance and can capture the details of the object well.

[0084] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.75 < BFL / f < 1.3. With the above range satisfied, a balance between good imaging quality and easy-to-assemble optical back focal length is achieved, which ensures the imaging quality of the optical lens while avoiding interference between the lens and other elements, and reduces the difficulty of camera module assembly process.

[0085] In some embodiments, the object side surface curvature radius R1 of the first lens and the image side surface curvature radius R2 of the first lens satisfy: 4.5 < R1 / R2 < 5.8. With the above condition satisfied, the surface shape of the first lens can be reasonably set to enhance the light collecting ability of the first lens, thereby realizing a larger field angle.

[0086] In some embodiments, the second lens satisfies: 0.6 < R3 / R4 < 0.75. By satisfying the above relationship, the ratio of the curvature radius of the object side surface of the second lens at the optical axis and the curvature radius of the image side surface of the second lens at the optical axis is reasonably configured, the shape of the second lens is controlled, the spherical aberration, chromatic aberration and field curvature of the optical system are comprehensively balanced, the risk of ghosting is reduced, the resolving power of the optical system is improved, and the processing difficulty of the second lens is reduced.

[0087] In some embodiments, the second lens satisfies: -6 < (R3+R4) / (R3-R4) < -4.5. By satisfying the above condition, the curvature radii of the object side surface and the image side surface of the second lens are reasonably controlled, so as to facilitate the control of the shape of the second lens, the optimization of the aberration balance of the lens group, and the improvement of the imaging quality.

[0088] In some embodiments, the third lens satisfies: -0.55 < (R5+R6) / (R5-R6) < -0.3. By satisfying the above range, the light ray trend is more stable, the coma and field curvature are corrected, the imaging flatness is improved, and the imaging quality of the optical lens is improved.

[0089] In some embodiments, the seventh lens satisfies: -4.2 < (R13+R14) / (R13-R14) < 0. By satisfying the above range, the shape of the object side surface and the image side surface of the seventh lens is reasonably limited, the seventh lens has an appropriate surface type, the light ray trend of the edge field of view is controlled, and the imaging quality of the edge field of view is improved.

[0090] In some embodiments, the second lens satisfies: 1 < CT2 / CT3 < 1.6. By satisfying the above condition, the ratio of the thickness of the second lens on the optical axis and the thickness of the third lens on the optical axis is reasonably configured, the second lens and the third lens can be mutually regulated, and the miniaturization feature of the optical system is maintained.

[0091] In some embodiments, the fourth lens and the fifth lens satisfy: 0.05 < (CT45+CT67) / CT4 < 0.2. By satisfying the above condition, the gap and the center thickness between the fourth lens and the fifth lens and between the sixth lens and the seventh lens are reasonably arranged, and the miniaturization feature of the system is facilitated.

[0092] In some embodiments, the center thickness CT2 of the second lens and the edge thickness ET2 of the second lens satisfy: 0.9 < CT2 / ET2 < 1. By making the optical system satisfy the above relationship, the molding of the lens is facilitated, the difficulty of assembly is reduced, and the field curvature of the system can be effectively corrected.

[0093] In some embodiments, the object-side half-field radius sagittal height SAG71 of the seventh lens, the image-side half-field radius sagittal height SAG72 of the seventh lens, and the center thickness CT7 of the seventh lens satisfy: -0.1 < (SAG72-SAG71) / CT7 < 0.1. By controlling the relationship between the height difference of the sagittal heights of the image side and the object side of the seventh lens and the center thickness of the seventh lens, the coma of the off-axis field is corrected, and the imaging quality of the optical lens off-axis field is improved.

[0094] In some embodiments, the object-side half-field radius DM11 of the first lens and the image-side half-field radius DM72 of the seventh lens satisfy: 1.5 < DM11 / DM72 < 1.7. By satisfying the above condition, the light rays in a large range are ensured to enter the system while effectively reducing the aperture size of the lens, which is beneficial to balance the field of view and the aperture of the lens.

[0095] In some embodiments, the Abbe number Vd6 of the sixth lens and the Abbe number Vd7 of the seventh lens satisfy: 45 < Vd6-Vd7 < 50. When the above relationship is satisfied, the lens material can be selected appropriately, so that the chromatic aberration can be effectively corrected, the imaging clarity of the optical system is improved, and the imaging quality of the optical system is improved.

[0096] 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: 0.89 < (IH / 2) / (f x θ) < 0.92. By satisfying the above condition, small distortion can be better achieved, and high resolution can be more favorably achieved.

[0097] In some embodiments, the optical lens satisfies the condition formula: 30mm < TTL < 34mm, 4mm < f < 4.3mm, 140° < FOV < 143°, 9mm < IH < 9.5mm, 1.4 < Fno < 1.9, 13° < CRA < 19°, 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, Fno represents the aperture value of the optical lens, and CRA represents the chief ray incidence angle at the maximum image height. Satisfying the above condition indicates that the optical lens provided by the embodiments of the present application at least 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 front and back of the subject can remain relatively clear; has a large field of view angle, provides a wider shooting field of view for application scenarios such as vehicle-mounted front-view lenses, and captures more image information; has a large imaging surface, can match a large-size chip to realize high-definition imaging; and has a large aperture, and can realize high-definition imaging even in a complex light environment.

[0098] 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 characteristic of the glass itself. The first lens, the third lens, the fifth lens and the sixth lens in the optical lens provided by the present application can adopt glass material, and the second lens, the fourth lens and the seventh lens can adopt plastic material, so that the cost can be effectively reduced, the aberration can be corrected, the volume can be reduced, the thermal stability performance can be improved, and an optical lens product with higher cost performance can be provided.

[0099] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens can adopt 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, the third lens, the fifth lens and the sixth lens of the present application adopt a spherical lens, and the second lens, the fourth lens and the seventh lens adopt an aspherical lens.

[0100] In various embodiments of the present application, when the lens adopts an aspherical lens, the shape of each aspherical surface of the optical lens satisfies the following equation:

[0101] ;

[0102] Wherein, z is the distance of the curved surface and the curved surface vertex in the direction of the optical axis, h is the distance of the optical axis to the curved surface, c is the curvature of the curved surface vertex, K is the quadratic curved surface coefficient, B, C, D, E, F, G, H are the fourth order, sixth order, eighth order, tenth order, twelfth order, fourteenth order, sixteenth order curved surface coefficients respectively.

[0103] The application will be further described in the following embodiments. In each embodiment, the thickness, the radius of curvature, the material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only the preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments only, any change, substitution, combination or simplification made without departing from the innovative points of the application should be regarded as equivalent replacement, and all are included in the protection scope of the application.

[0104] Embodiment 1

[0105] Please refer to Figure 1 , which is a structural schematic diagram of the optical lens 100 provided in the embodiment 1 of the application, the optical lens 100 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 diaphragm ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7 and a filter G1.

[0106] The first lens L1 has negative focal power, the object side surface S1 is a convex surface, and the image side surface S2 is a concave surface;

[0107] The second lens L2 has negative focal power, the object side surface S3 is a concave surface, and the image side surface S4 is a convex surface;

[0108] The third lens L3 has positive focal power, the object side surface S5 is a convex surface, and the image side surface S6 is a convex surface;

[0109] The fourth lens L4 has positive focal power, the object side surface S7 is a convex surface, and the image side surface S8 is a convex surface;

[0110] The fifth lens L5 has negative focal power, the object side surface S9 is a convex surface, and the image side surface is a concave surface;

[0111] The sixth lens L6 has positive focal power, the object side surface is a convex surface, and the image side surface S11 is a convex surface;

[0112] The fifth lens L5 and the sixth lens L6 constitute a cemented lens group, that is, the cemented surface of the image side surface of the fifth lens L5 and the object side surface of the sixth lens L6 is S10;

[0113] The seventh lens L7 has negative focal power, the object side surface S12 is a concave surface, and the image side surface S13 is a convex surface;

[0114] The object side S14 and the image side S15 of the filter G1 are both planar surfaces.

[0115] The imaging surface S16 is a planar surface.

[0116] The first lens L1, the third lens L3, the fifth lens L5, and the sixth lens L6 are glass spherical lenses, the second lens L2 is a glass aspherical lens, and the fourth lens L4 and the seventh lens L7 are plastic aspherical lenses.

[0117] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0118] Table 1-1

[0119]

[0120] The surface type parameters of the aspherical lenses in the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0121] Table 1-2

[0122]

[0123] In this embodiment, the field curvature curve, the F-Theta distortion curve, the axial aberration curve, the transverse chromatic aberration curve, the MTF curve, and the relative illumination curve of the optical lens 100 are shown in FIGS. 1-1 to 1-5, respectively. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7

[0124] 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 -0.02mm~0.02mm, which shows that the optical lens can well correct the field curvature.

[0125] 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 -10%~0, which shows that the optical lens can well correct the distortion.

[0126] Figure 4 ​The axial aberration curve of the embodiment 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 shift of the axial aberration is controlled within ±0.01 mm, which shows that the optical lens can correct the axial aberration well.

[0127] Figure 5 The curve of the axial aberration of the embodiment 1 is shown, which represents the color difference of each wavelength at different image heights on the imaging plane relative to the central wavelength (0.546 μm), the horizontal axis represents the axial 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 axial aberration of the longest wavelength and the shortest wavelength is controlled within ±1.5 μm, which shows that the optical lens can correct the color difference very well.

[0128] Figure 6 The MTF (modulation transfer function) curve of the embodiment 1 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies under each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of the embodiment is above 0.45 in the full field of view, and in the range of 0-120 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0129] Figure 7 The relative luminance curve of the embodiment 1 is shown, which represents the relative luminance value of different field angles on the imaging plane, the horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative luminance (unit: %). As can be seen from the figure, the relative luminance value of the optical lens is still greater than 70% at the maximum half field angle, which shows that the optical lens has good relative luminance.

[0130] Embodiment 2

[0131] Please refer to Figure 8 , which is a structural schematic diagram of the optical lens 200 provided in the embodiment 2 of the present application, and the main difference between the embodiment and the embodiment 1 is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0132] The related parameters of each lens in the optical lens 200 in the embodiment 2 are shown in Table 2-1.

[0133] Table 2-1

[0134]

[0135] The surface type parameters of the aspheric lens of the optical lens 200 in the embodiment 2 are shown in Table 2-2.

[0136] Table 2-2

[0137]

[0138] In the embodiment, the field curvature curve, the F-Theta distortion curve, the axial aberration curve, the transverse chromatic aberration curve, the MTF curve and the relative illumination curve of the optical lens 200 are respectively shown in Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 、 Figure 14 It can be seen from Figure 9 that the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.04mm~0.02mm, which indicates that the optical lens 200 can well correct the field curvature. It can be seen from Figure 10 that the F-Theta distortion of the optical lens 200 is controlled within -10%~0, which indicates that the optical lens can well correct the distortion. It can be seen from Figure 11 that the offset of the axial aberration is controlled within -0.02mm~0.01mm, which indicates that the optical lens 200 can well correct the axial aberration. It can be seen from Figure 12 that the transverse chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1μm~1μm, which indicates that the optical lens 200 can well correct the chromatic aberration. It can be seen from Figure 13 that the MTF value of the embodiment is above 0.4 in the full field of view, and in the range of 0~120lp / mm, the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency. It can be seen from Figure 14 that the relative illumination value of the optical lens 200 is still greater than 70% at the maximum half field of view, which indicates that the optical lens 200 has good relative illumination.

[0139] Embodiment 3

[0140] Please refer to Figure 15 , which is a structural schematic diagram of the optical lens 300 provided in the embodiment 3 of the application. Compared with the embodiment 1, the main difference is that the image side surface S13 of the seventh lens L7 is concave at the near optical axis; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0141] The related parameters of each lens in the optical lens 300 in the embodiment 3 are shown in Table 3-1.

[0142] Table 3-1

[0143]

[0144] The surface type parameters of the aspherical lenses of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0145] Table 3-2

[0146]

[0147] In the present embodiment, the field curvature curve, the F-Theta distortion curve, the axial aberration curve, the transverse chromatic aberration curve, the MTF curve and the relative illumination curve of the optical lens 300 are shown in Figure 16 , Figure 17 , Figure 18 , Figure 19 , Figure 20 , Figure 21 It can be seen from Figure 16 that the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.03 mm, which indicates that the optical lens 300 can well correct the field curvature. It can be seen from Figure 17 that the F-Theta distortion of the optical lens 300 is controlled within -12%~0, which indicates that the optical lens 300 can well correct the distortion. It can be seen from Figure 18 that the shift of the axial aberration is controlled within -0.01 mm~0.01 mm, which indicates that the optical lens 300 can well correct the axial aberration. It can be seen from Figure 19 that the transverse chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±1.5 μm, which indicates that the optical lens 300 can well correct the chromatic aberration. It can be seen from Figure 20 that the MTF value of the present embodiment is above 0.48 in the full field of view, and in the range of 0~120 lp / mm, the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency. It can be seen from Figure 21 that the relative illumination value of the optical lens 300 is still greater than 60% at the maximum half field of view, which indicates that the optical lens 300 has good relative illumination.

[0148] Embodiment 4

[0149] Please refer to Figure 22 , which is a structural schematic diagram of the optical lens 400 provided in Embodiment 4 of the present application. Compared with Embodiment 1, the main difference is that the image side surface S13 of the seventh lens L7 is a concave surface at the near optical axis; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0150] The related parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0151] Table 4-1

[0152]

[0153] The surface profile parameters of the aspherical lens of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0154] Table 4-2

[0155]

[0156] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, MTF curve, and relative illumination curve of the optical lens 400 are shown in FIGS. 4-2A, 4-2B, 4-2C, 4-2D, 4-2E, and 4-2F, respectively. Figure 23 、 Figure 24 、 Figure 25 、 Figure 26 、 Figure 27 、 Figure 28 From FIGS. 4-2A, 4-2B, 4-2C, 4-2D, 4-2E, and 4-2F, it can be seen that the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.03 mm, which indicates that the optical lens 400 can well correct the field curvature. Figure 23 From FIGS. 4-2A, 4-2B, 4-2C, 4-2D, 4-2E, and 4-2F, it can be seen that the F-Theta distortion of the optical lens 400 is controlled within -11%~0, which indicates that the optical lens 400 can well correct the distortion. Figure 24 From FIGS. 4-2A, 4-2B, 4-2C, 4-2D, 4-2E, and 4-2F, it can be seen that the shift of the axial aberration is controlled within -0.01 mm~0.01 mm, which indicates that the optical lens 400 can well correct the axial aberration. Figure 25 From FIGS. 4-2A, 4-2B, 4-2C, 4-2D, 4-2E, and 4-2F, it can be seen that the transverse chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±1.5 μm, which indicates that the optical lens 400 can well correct the chromatic aberration. Figure 26 From FIGS. 4-2A, 4-2B, 4-2C, 4-2D, 4-2E, and 4-2F, it can be seen that the MTF value of this embodiment is above 0.3 in the full field of view, and in the range of 0~120 lp / mm, the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in the low frequency and high frequency cases. Figure 27 From FIGS. 4-2A, 4-2B, 4-2C, 4-2D, 4-2E, and 4-2F, it can be seen that the relative illumination value of the optical lens 400 is still greater than 60% at the maximum half field of view, which indicates that the optical lens 400 has good relative illumination. Figure 28

[0157] Please refer to Table 5, 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 maximum field of view FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0158] Table 5

[0159]

[0160] ​In summary, the optical lens provided by the present application adopts seven lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens is improved, the aberration is reduced, and the imaging quality of the optical lens is improved, so that the lens has one or more advantages of large aperture, large field of view, good resolving power, high illumination, high imaging quality, etc.

[0161] 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 description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0162] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to 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, in total seven pieces of lenses, characterized in that, In order from the object side to the imaging surface along the optical axis, successively comprise: a first lens with negative focal length, the object side surface of which is convex, and the image side surface of which is concave; a second lens with negative focal length, the object side surface of which is concave, and the image side surface of which is convex; a third lens with positive focal length, the object side surface of which is convex, and the image side surface of which is convex; a fourth lens with positive focal length, the object side surface of which is convex, and the image side surface of which is convex; a fifth lens with negative focal length, the object side surface of which is convex, and the image side surface of which is concave; a sixth lens with positive focal length, the object side surface of which is convex, and the image side surface of which is convex; a seventh lens with negative focal length, the object side surface of which is concave; wherein the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -75 < f2 / f < -20; the object side surface half radius sagittal height SAG41 of the fourth lens, the image side surface half radius sagittal height SAG42 of the fourth lens, and the central thickness CT4 of the fourth lens satisfy: -0.4 < (SAG42-SAG41) / CT4 < -0.

25.

2. The optical lens of claim 1, wherein, The combined focal length f56 of the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 3.5 < f56 / f < 7.

2.

3. The optical lens of claim 1, wherein, The combined focal length f123 of the first lens, the second lens, and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: 0.45 < f123 / f4567 < 0.

55.

4. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.3 < f6 / f < 1.

4.

5. The optical lens of claim 1, wherein, The maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 75° < FOV / Fno < 100°.

6. The optical lens of claim 1, wherein, The real image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.2 < IH / EPD < 4.

2.

7. The optical lens of claim 1, wherein, The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 7.5 < TTL / f < 8.

8. The optical lens of claim 1, wherein, The total sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis and the total optical length TTL of the optical lens satisfy: 0.55 < ∑CT / TTL < 0.

65.

9. The optical lens of claim 1, wherein, The focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: 0.05 < f1 / f7 < 0.

4.

10. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 4.4 < f4 / f < 5.5.

Images