Optical lens

Abstract

The application provides an optical lens which is composed of seven lenses and sequentially comprises, along an optical axis from an object side to an imaging surface, a first lens with negative optical power, the object side of which is a convex surface and the image side of which is a concave surface; a second lens with negative optical power, the object side of which is a convex surface and the image side of which is a concave surface; a third lens with negative optical power, the object side of which is a concave surface and the image side of which is a concave surface; a fourth lens with positive optical power, the object side of which is a convex surface and the image side of which is a concave surface; a fifth lens with positive optical power, the object side of which is a convex surface and the image side of which is a convex surface; a sixth lens with negative optical power, the object side of which is a concave surface and the image side of which is a convex surface; and a seventh lens with positive optical power, the object side of which is a convex surface and the image side of which is a concave surface. The optical lens provided by the application can improve the imaging quality of the optical lens, reduce aberration and improve the imaging quality of the optical lens 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, in particular to an optical lens. BACKGROUND

[0002] With the continuous improvement of people's requirements for driving experience, vehicle application type optical lenses are used more and more in intelligent driving, and the status of vehicle optical lenses in the automobile industry is continuously improved. In the field of vehicle driving, in order to improve the driving safety and intelligentization of vehicles, it is necessary to monitor the vehicle cabin, and the OMS (passenger monitoring) vehicle lens has developed rapidly. The existing vehicle cabin monitoring lens generally has a resolution of about 1M or 2M, and as the FOV of the lens increases, the angular resolution and resolution decrease sharply. In addition to the requirements of the OMS system lens for the optical lens to have a light and thin shape with a small front aperture and to have high pixel and high resolution, the optical lens is also required to be able to clearly image under low illumination conditions, so it is necessary to develop an optical lens with good imaging effect. SUMMARY

[0003] 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.

[0004] The technical scheme adopted by the present application is:

[0005] An optical lens composed of seven lenses, including, along the optical axis from the object side to the imaging surface:

[0006] The first lens has a negative focal length, the object side surface is convex, and the image side surface is concave;

[0007] The second lens has a negative focal length, the object side surface is convex, and the image side surface is concave;

[0008] The third lens has a negative focal length, the object side surface is concave, and the image side surface is concave;

[0009] The fourth lens has a positive focal length, the object side surface is convex, and the image side surface is concave;

[0010] The fifth lens has a positive focal length, the object side surface is convex, and the image side surface is convex;

[0011] The sixth lens has a negative focal length, the object side surface is concave, and the image side surface is convex;

[0012] The seventh lens has a positive focal length, the object side surface is convex, and the image side surface is concave;

[0013] The object side surface curvature radius R13 of the seventh lens and the image side surface curvature radius R14 of the seventh lens satisfy: -0.5 < (R13-R14) / (R13+R14) < 0.

[0014] Further preferably, the total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.6 < TTL / f < 7; the total track length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.2 < TTL / IH < 2.7.

[0015] Further preferably, 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: 4.2 < IH / EPD < 6.3; the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the combined focal length f567 of the fifth lens, the sixth lens and the seventh lens satisfy: -1.65 < f1234 / f567 < -1.1.

[0016] Further preferably, 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: 2.25 < IH / f < 3.1; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.5 < BFL / f < 0.9.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -5.5 < f2 / f < -3.9; the effective focal length f of the optical lens and the object side surface curvature radius R3 of the second lens satisfy: 0.55 < R3 / f < 0.75.

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -2.75 < f3 / f < -2.1; the object side surface curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: -1.9 < R5 / f < -1.4; the image side surface curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: 5.7 < R6 / f < 7.4.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.8 < f4 / f < 2.2; the effective focal length f of the optical lens and the image side surface curvature radius R8 of the fourth lens satisfy: 12.9 < R8 / f < 53.1.

[0020] It is further preferred that the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -0.9 < f6 / f < -0.7; the effective focal length f of the optical lens and the image-side surface curvature radius R12 of the sixth lens satisfy: -3.5 < R12 / f < -2.3.

[0021] It is further preferred that the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 2.7 < f7 / f < 3.55; the effective focal length f of the optical lens and the image-side surface curvature radius R14 of the seventh lens satisfy: 1.4 < R14 / f < 2.6.

[0022] It is further preferred that the object-side surface curvature radius R11 of the sixth lens and the image-side surface curvature radius R12 of the sixth lens satisfy: -1 < (R11-R12) / (R11+R12) < -0.5; the object-side surface curvature radius R5 of the third lens and the image-side surface curvature radius R6 of the third lens satisfy: -0.8 < (R5+R6) / (R5-R6) < -0.3.

[0023] Compared with the prior art, 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 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 super wide angle, large aperture, miniaturization, high pixel, etc. BRIEF DESCRIPTION OF DRAWINGS

[0024] The above and / or additional aspects and advantages of the application will become apparent and be readily understood from the following description, taken in connection with the accompanying drawings, in which:

[0025] Figure 1 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the application.

[0026] Figure 2 FIG. 2 is a field curvature curve of the optical lens according to the embodiment of the application.

[0027] Figure 3 FIG. 3 is an F-Theta distortion curve of the optical lens according to the embodiment of the application.

[0028] Figure 4 FIG. 4 is an axial aberration curve of the optical lens according to the embodiment of the application.

[0029] Figure 5 FIG. 5 is a transverse chromatic aberration curve of the optical lens according to the embodiment of the application.

[0030] Figure 6 FIG. 6 is an MTF curve of the optical lens according to the embodiment of the application.

[0031] Figure 7 Structure diagram of the optical lens in Embodiment 2 of the present application.

[0032] Figure 8 Field curvature curve diagram of the optical lens in Embodiment 2 of the present application.

[0033] Figure 9 F-Theta distortion curve diagram of the optical lens in Embodiment 2 of the present application.

[0034] Figure 10 Axial aberration curve diagram of the optical lens in Embodiment 2 of the present application.

[0035] Figure 11 Vignetting curve diagram of the optical lens in Embodiment 2 of the present application.

[0036] Figure 12 MTF curve diagram of the optical lens in Embodiment 2 of the present application.

[0037] Figure 13 Structure diagram of the optical lens in Embodiment 3 of the present application.

[0038] Figure 14 Field curvature curve diagram of the optical lens in Embodiment 3 of the present application.

[0039] Figure 15 F-Theta distortion curve diagram of the optical lens in Embodiment 3 of the present application.

[0040] Figure 16 Axial aberration curve diagram of the optical lens in Embodiment 3 of the present application.

[0041] Figure 17 Vignetting curve diagram of the optical lens in Embodiment 3 of the present application.

[0042] Figure 18 MTF curve diagram of the optical lens in Embodiment 3 of the present application.

[0043] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0044] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It is to be understood that the detailed description is merely descriptive of embodiments of the present application and is not intended in any way to limit the scope of the present application. Throughout the specification, like reference numerals refer to like elements. The expression “and / or” includes any and all combinations of one or more of the associated listed items.

[0045] It should be noted that the terms first, second, third, etc. in the present specification are only used to distinguish one feature from another, 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.

[0046] 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.

[0047] In the present specification, the paraxial region refers to a region near the optical axis. If the 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 the 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 imaging surface is referred to as the image side surface of the lens.

[0048] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. In addition, when expressions such as "at least one of" appear after a list of one or more items, the phrase "at least one of" is intended to refer to any single one of the listed items individually, as well as to all possible combinations of two or more of the listed items. Furthermore, when describing embodiments of the present application, the use of "may" indicates that one or more embodiments of the present application. Also, the word "exemplary" is intended to mean an example or an illustration.

[0049] 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 should also be understood that the terms 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.

[0050] 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 drawings and in conjunction with embodiments.

[0051] The optical lens provided by the embodiments 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.

[0052] In some embodiments, the first lens can have a negative focal power, a convex object side surface, and a concave image side surface. The second lens can have a negative focal power, a convex object side surface, and a concave image side surface. The third lens can have a negative focal power, a concave object side surface, and a concave image side surface. The fourth lens can have a positive focal power, a convex object side surface, and a concave image side surface. The fifth lens can have a positive focal power, a convex object side surface, and a convex image side surface. The sixth lens can have a negative focal power, a concave object side surface, and a convex image side surface. The seventh lens can have a positive focal power, a convex object side surface, and a concave image side surface.

[0053] In some embodiments, the optical lens can further include 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. 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.

[0054] In some embodiments, the optical lens can further include a filter, which can be disposed 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.

[0055] In some embodiments, the fifth lens and the sixth lens can be cemented to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the sensitivity of the optical lens to decentration, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0056] In some embodiments, the object side surface radius of curvature R13 of the seventh lens and the image side surface radius of curvature R14 of the seventh lens satisfy: -0.5 < (R13-R14) / (R13+R14) < 0. Satisfying the above range, the seventh lens has a suitable surface shape, the light ray trend smoothly transitions to the rear, the height of the light ray incident to the rear is reduced, the upward trend of the light ray is slowed down, the light energy loss caused by the large angle between the main light ray and the chip when the large field of view light ray reaches the imaging surface is avoided, the illumination of the edge field of view is improved, and the short total optical length is facilitated. More specifically, -0.34 < (R13-R14) / (R13+R14) < -0.2.

[0057] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.6 < TTL / f < 7. Satisfying the above range, the length of the lens can be effectively limited, which is conducive to the miniaturization of the optical lens. More specifically, 6.22 < TTL / f < 6.84.

[0058] In some embodiments, the total track 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: 2.2 < TTL / IH < 2.7. Satisfying the above range ensures that the lens has a larger image surface under the condition of equal total length, which can match a larger imaging chip to realize high-definition imaging, and better realize the balance between small total length and large image surface of the lens. More specifically, 2.44 < TTL / IH < 2.48.

[0059] In some embodiments, 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: 4.2 < IH / EPD < 6.3. Satisfying the above range can increase the width of the light beam entering the optical lens, so that the brightness of the optical lens at the image surface is improved to avoid dark corners. More specifically, 4.63 < IH / EPD < 5.71.

[0060] In some embodiments, the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the combined focal length f567 of the fifth lens, the sixth lens and the seventh lens satisfy: -1.65 < f1234 / f567 < -1.1. Satisfying the above range, by reasonably setting the lens group relationship before and after the diaphragm, it is beneficial to balance various aberrations of the system and improve the overall imaging quality. More specifically, -1.52 < f1234 / f567 < -1.24.

[0061] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.25 < IH / f < 3.1. Satisfying the above range controls the image height and focal length of the optical lens within a reasonable range, which helps the optical lens to have the characteristics of large image surface and improves the imaging quality. More specifically, 2.51 < IH / f < 2.8.

[0062] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.5 < BFL / f < 0.9. Satisfying the above range limits the optical lens to have a suitable back focus, which facilitates the reasonable arrangement of the positions of the lenses and reduces the processing and assembly difficulty. More specifically, 0.56 < BFL / f < 0.8.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -5.5 < f2 / f < -3.9; the effective focal length f of the optical lens and the radius of curvature R3 on the object side of the second lens satisfy: 0.55 < R3 / f < 0.75. Satisfying the above ranges, the second lens has a suitable negative focal power and surface shape, can share the negative focal power of the front end of the optical lens, thereby avoiding excessive deflection of light caused by excessive concentration of the focal power of the first lens, and reducing the difficulty of chromatic aberration correction of the optical lens. More specifically, -5.04 < f2 / f < -4.28; 0.64 < R3 / f < 0.69.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -2.75 < f3 / f < -2.1; the radius of curvature R5 on the object side of the third lens and the effective focal length f of the optical lens satisfy: -1.9 < R5 / f < -1.4; the radius of curvature R6 on the image side of the third lens and the effective focal length f of the optical lens satisfy: 5.7 < R6 / f < 7.4. Satisfying the above ranges, the third lens has a suitable negative focal power and surface shape, has the effect of diverging light, further diverges the light emitted by the first lens and the second lens at the same field of view, can disperse the central light and the edge light of each field of view, can make the rear optical system have a larger light receiving surface to receive the light emitted by the third lens on the image side, realize a larger light amount, and is beneficial to increasing the relative luminance. More specifically, -2.5 < f3 / f < -2.38; -1.74 < R5 / f < -1.6; 6.28 < R6 / f < 6.74.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.8 < f4 / f < 2.2; the effective focal length f of the optical lens and the radius of curvature R8 on the image side of the fourth lens satisfy: 12.9 < R8 / f < 53.1. Satisfying the above ranges, the light can be effectively converged, the difficulty of edge field distortion correction is reduced, the lens can have smaller distortion while realizing a large field of view, and the overall imaging quality is improved. More specifically, 1.99 < f4 / f < 2.05; 14.31 < R8 / f < 48.28.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -0.9 < f6 / f < -0.7; the effective focal length f of the optical lens and the image-side surface curvature radius R12 of the sixth lens satisfy: -3.5 < R12 / f < -2.3. Satisfying the above ranges, various aberrations generated by the front lens group can be effectively balanced, while the degree of divergence of light is increased, the area of light entering the imaging surface is increased, large target surface imaging of the lens is achieved, and the imaging quality of the optical lens is improved. More specifically, -0.79 < f6 / f < -0.76; -3.16 < R12 / f < -2.53.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 2.7 < f7 / f < 3.55; the effective focal length f of the optical lens and the image-side surface curvature radius R14 of the seventh lens satisfy: 1.4 < R14 / f < 2.6. Satisfying the above ranges, the seventh lens can have appropriate positive focal power, which is beneficial to balancing the astigmatism of the optical lens and improving the imaging quality of the optical lens. More specifically, 2.99 < f7 / f < 3.23; 1.54 < R14 / f < 2.35.

[0068] In some embodiments, the object-side surface curvature radius R11 of the sixth lens and the image-side surface curvature radius R12 of the sixth lens satisfy: -1 < (R11-R12) / (R11+R12) < -0.5. Satisfying the above ranges, the surface type of the sixth lens is controlled, which is beneficial to increasing the imaging area and the field of view of the optical lens, balancing the aberration of the optical lens, and improving the imaging quality of the optical lens. More specifically, -0.78 < (R11-R12) / (R11+R12) < -0.72.

[0069] In some embodiments, the object-side surface curvature radius R5 of the third lens and the image-side surface curvature radius R6 of the third lens satisfy: -0.8 < (R5+R6) / (R5-R6) < -0.3. Satisfying the above ranges, the light smoothly transitions, which can effectively correct the distortion of the edge field of view, reduce the deformation degree of the edge of the photographed picture, and improve the picture quality. More specifically, -0.62 < (R5+R6) / (R5-R6) < -0.56.

[0070] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 70° < FOV / Fno < 85°. Satisfying the above ranges, the optical lens has a suitable field of view and aperture value, which can collect light at a large angle and obtain good imaging quality. More specifically, 75.73° < FOV / Fno < 78.31°.

[0071] In some embodiments, the effective focal length f of the optical lens, 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: 50° < (f x FOV) / IH < 60°. By reasonably limiting the relationship among the focal length, the field of view, and the image height of the optical lens, the optical lens has a large field of view and a large image surface, thereby having good optical performance and being capable of capturing details of the object. More specifically, 55.49° < (f x FOV) / IH < 57.52°.

[0072] In some embodiments, the total 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: 0.5 < ∑CT / TTL < 0.6. By satisfying the above range, the total length of the optical lens can be effectively compressed, and the structure design and the production process of the optical lens are facilitated. More specifically, 0.52 < ∑CT / TTL < 0.55.

[0073] In some embodiments, the effective focal length f of the optical lens, the radian θ of the maximum half field of view, and the real image height IH corresponding to the maximum field of view satisfy: 0.99 < (IH / 2) / (f x θ) < 1.04. By satisfying the above range, the ultra-wide-angle characteristics of the optical lens are facilitated, and the optical lens is capable of having a smaller distortion.

[0074] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -3 < f1 / f < -2.4. By setting the first lens to have a negative refractive power, the first lens is capable of receiving a larger angle of light and collecting as much light as possible into the rear optical system, thereby achieving a large field of view and increasing the light flux. More specifically, -2.75 < f1 / f < -2.64.

[0075] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.7 < f5 / f < 0.9; and the effective focal length f of the optical lens and the radius of curvature R9 of the object side surface of the fifth lens satisfy: 0.9 < R9 / f < 1.15. By setting the fifth lens to have a positive refractive power, the light is converged while the field curvature and the distortion of the optical lens are corrected, thereby improving the imaging quality of the optical lens. More specifically, 0.77 < f5 / f < 0.84; and 0.99 < R9 / f < 1.04.

[0076] In some embodiments, an image-side half-field radius sag Sag12 of the sixth lens and a image-side half-field radius d12 of the sixth lens satisfy: -0.3 < Sag12 / d12 < 0; an image-side half-field radius sag Sag14 of the seventh lens and a image-side half-field radius d14 of the seventh lens satisfy: 0 < Sag14 / d14 < 0.3. Satisfying the above ranges helps to control the trend of edge field of view light, highlight the central field of view details of the optical lens. More specifically, -0.19 < Sag12 / d12 < -0.15; 0.1 < Sag14 / d14 < 0.19.

[0077] In some embodiments, the optical lens satisfies the condition: 2mm < f < 2.5mm, 1mm < EPD < 1.35mm, 12.6mm < TTL < 16.5mm, 1.65 < Fno < 2.25, 17.4° < CRA < 22°, 1.1mm < BFL < 1.9mm, 130° < FOV < 170°, 5.1mm < IH < 6.7mm; wherein f represents an effective focal length of the optical lens, EPD represents an entrance pupil diameter of the optical lens, TTL represents an overall optical length of the optical lens, Fno represents an aperture value of the optical lens, CRA represents a chief ray angle of incidence at a maximum image height of the optical lens, BFL represents a back focal length of the optical lens, FOV represents a maximum field of view angle of the optical lens, and IH represents a real image height corresponding to the maximum field of view angle of the optical lens. Satisfying the above conditions indicates that the optical lens provided by the embodiments of the present application at least has the characteristics of miniaturization, large target surface, large field of view angle, large aperture, etc. More specifically, 2.19mm < f < 2.26mm, 1.08mm < EPD < 1.23mm, 14.03mm < TTL < 15.01mm, 1.84 < Fno < 2.06, 19.23° < CRA < 20.04°, 1.27mm < BFL < 1.75mm, 144° < FOV < 156°, 5.67mm < IH < 6.14mm.

[0078] In some embodiments, the material of the lenses in the optical lens provided by the present application can be glass or plastic. When the material of the lenses is plastic, the production cost can be effectively reduced. When the material of the lenses is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The first lens and the fourth lens in the optical lens provided by the present application are glass lenses, and the second lens, the third lens, the fifth lens, the sixth lens and the seventh lens are plastic lenses. The optical lens of the present application adopts a glass-plastic hybrid structure to improve the thermal stability.

[0079] 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 a spherical structure, an aspherical structure can effectively reduce aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better achieving miniaturization of the lens. More specifically, the first lens and the fourth lens of the present application adopt a spherical lens, and the second lens, the third lens, the fifth lens, the sixth lens and the seventh lens all adopt an aspherical lens, which can effectively reduce aberration of the optical lens, thereby reducing the number of lenses and the size of the lenses, and better achieving miniaturization of the lens.

[0080] 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:

[0081]

[0082] 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 of 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 and F are respectively the fourth-order, sixth-order, eighth-order, tenth-order and twelfth-order surface coefficients.

[0083] The present application is further described in the following embodiments. In various embodiments, the thickness, the radius of curvature and 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 preferred embodiments of the present application, but the embodiments of the present 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 present application should be regarded as equivalent replacement modes, and are included in the protection scope of the present application.

[0084] Embodiment 1

[0085] Please refer to Figure 1 , which is a structural schematic diagram of the optical lens 100 provided in the embodiment 1 of the present application. The optical lens 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 diaphragm ST, a fifth lens L5, a sixth lens L6, a seventh lens L7 and a filter G1.

[0086] The first lens L1 has a negative focal power, the object side surface S1 thereof is a convex surface, and the image side surface S2 thereof is a concave surface.

[0087] The second lens L2 has a negative focal power, the object side surface S3 thereof is a convex surface, and the image side surface S4 thereof is a concave surface.

[0088] The third lens L3 has a negative focal power, the object side surface S5 thereof is a concave surface, and the image side surface S6 thereof is a concave surface.

[0089] The fourth lens L4 has positive refractive power, the object side S7 is a convex surface, and the image side S8 is a concave surface;

[0090] The fifth lens L5 has positive refractive power, the object side S9 is a convex surface, and the image side S10 is a convex surface;

[0091] The sixth lens L6 has negative refractive power, the object side S10 is a concave surface, and the image side S11 is a convex surface;

[0092] The fifth lens L5 and the sixth lens L6 constitute a cemented lens group with positive refractive power, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens L6 is S10;

[0093] The seventh lens L7 has positive refractive power, the object side S12 is a convex surface, and the image side S13 is a concave surface;

[0094] The object side S14 and the image side S15 of the filter G1 are both flat surfaces;

[0095] The imaging surface S16 is a flat surface.

[0096] 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, and the seventh lens L7 are plastic aspherical lenses.

[0097] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0098] Table 1-1

[0099]

[0100] The surface type parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0101] Table 1-2

[0102] Surface number K B C D E F S3 -1.74E+00 1.92E-02 -1.09E-02 8.82E-04 3.03E-05 -6.62E-06 S4 -1.33E+00 2.55E-02 -1.60E-02 1.05E-03 2.75E-04 -2.41E-05 S5 -1.19E+01 -3.59E-02 2.16E-02 -5.76E-03 9.61E-04 -5.08E-05 S6 4.15E+01 -2.16E-02 1.32E-02 -3.52E-03 6.18E-04 -4.55E-05 S9 7.28E-01 -3.65E-02 7.41E-03 -8.61E-03 3.83E-03 -9.49E-04 S10 -2.51E+00 -2.95E-01 1.46E-01 -5.56E-02 1.58E-02 -1.76E-03 S11 -1.98E+01 -4.71E-02 1.98E-02 -4.18E-03 5.88E-04 -3.68E-05 S12 -5.18E+00 1.26E-03 -1.02E-03 9.87E-05 2.06E-05 -3.74E-06 S13 -7.96E+00 1.03E-02 -5.61E-03 1.10E-03 -9.73E-05 2.45E-06

[0103] Figure 2 The field curvature curve of the optical lens 100 in this embodiment is shown, which represents the bending degree of the 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 ±0.04 mm, which shows that the optical lens 100 can better correct the field curvature.

[0104] Figure 3The F-Theta distortion curve of the optical lens 100 in the embodiment is shown, which represents the distortion of different field angles on the imaging surface, the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the distortion value is controlled within ±1%, which shows that the optical lens 100 can better correct the distortion.

[0105] Figure 4 The axial aberration curve of the optical lens 100 in the embodiment is shown, which represents the axial 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, which shows that the optical lens 100 can better correct the axial aberration.

[0106] Figure 5 The transverse chromatic aberration curve of the optical lens 100 in the embodiment is shown, which represents the chromatic aberration of each wavelength at different image heights on the imaging surface relative to the central wavelength (0.555μm), 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 ±4μm, which shows that the optical lens 100 can better correct the chromatic aberration.

[0107] Figure 6 The modulation transfer function (MTF) curve of the optical lens 100 in the embodiment is shown, which represents the lens imaging modulation degree of 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 0.4 within the full field of view, and in the range of 0-160lp / 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 low frequency and high frequency cases.

[0108] Embodiment 2

[0109] Please refer to Figure 7 , which is a structural schematic diagram of the optical lens 200 provided in the embodiment 2 of the present application. Compared with the embodiment 1, the main difference is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0110] The related parameters of each lens in the optical lens 200 in the embodiment 2 are shown in Table 2-1.

[0111] Table 2-1

[0112]

[0113]

[0114] The surface profile parameters of the aspherical lenses of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0115] Table 2-2

[0116] Surface number K B C D E F S3 -1.81E+00 1.99E-02 -1.08E-02 8.94E-04 3.29E-05 -7.33E-06 S4 -1.32E+00 2.51E-02 -1.61E-02 1.03E-03 2.86E-04 -3.22E-05 S5 -1.27E+01 -3.64E-02 2.15E-02 -5.77E-03 9.60E-04 -5.41E-05 S6 5.00E+01 -2.08E-02 1.32E-02 -3.57E-03 5.90E-04 -3.38E-05 S9 7.08E-01 -3.52E-02 6.94E-03 -8.72E-03 4.11E-03 -1.05E-03 S10 -2.57E+00 -2.87E-01 1.43E-01 -5.72E-02 1.61E-02 -1.53E-03 S11 -3.26E+01 -4.81E-02 1.97E-02 -4.19E-03 5.93E-04 -3.61E-05 S12 -5.92E+00 7.45E-04 -1.09E-03 9.67E-05 2.01E-05 -3.58E-06 S13 -1.01E+01 1.07E-02 -5.75E-03 1.09E-03 -9.67E-05 2.84E-06

[0117] In the present embodiment, the field curvature curve, the F-Theta distortion curve, the axial aberration curve, the transverse chromatic aberration curve and the MTF curve of the optical lens 200 are shown in Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 respectively.

[0118] As can be seen from Figure 8 , the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.07 mm, which indicates that the optical lens 200 can well correct the field curvature.

[0119] As can be seen from Figure 9 , the distortion value is controlled within ±3%, which indicates that the optical lens 200 can well correct the distortion.

[0120] As can be seen from Figure 10 , the shift of the axial aberration is controlled within ±0.04 mm, which indicates that the optical lens 200 can well correct the axial aberration.

[0121] As can be seen from Figure 11 , the transverse chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±3 μm, which indicates that the optical lens 200 can well correct the chromatic aberration.

[0122] As can be seen from Figure 12 , the MTF value of the present embodiment is above 0.38 in the full field of view, and in the range of 0-160 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.

[0123] Embodiment 3

[0124] Please refer to Figure 13 , which is a structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present application. Compared with Embodiment 1, the main difference is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0125] The related parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0126] Table 3-1

[0127]

[0128] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0129] Table 3-2

[0130]

[0131]

[0132] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 300 are respectively as follows: Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 As shown.

[0133] from Figure 14 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.1mm, indicating that the optical lens 300 can effectively correct field curvature.

[0134] from Figure 15 As can be seen, the distortion value is controlled within ±4%, indicating that the optical lens 300 can correct distortion well.

[0135] from Figure 16 As can be seen, the axial aberration offset is controlled within ±0.04mm, indicating that the optical lens 300 can correct axial aberration well.

[0136] from Figure 17 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within ±4μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0137] from Figure 18 As can be seen, the MTF value of this embodiment is above 0.4 throughout the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0138] Please refer to Table 4 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0139] Table 4

[0140]

[0141]

[0142] In summary of the above embodiments, 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 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 super wide angle, large aperture, miniaturization, high pixel, etc.

[0143] In the description of the present specification, the description referring to 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.

[0144] The above described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that for those skilled 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 consisting of seven pieces of lenses, characterized in that, In order from the object side to the imaging plane along the optical axis, sequentially comprise: a first lens with negative focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a second lens with negative focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a third lens with negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface; a fourth lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a fifth lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a sixth lens with negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; a seventh lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; wherein the object side surface curvature radius R13 of the seventh lens and the image side surface curvature radius R14 of the seventh lens satisfy: -0.5<(R13-R14) / (R13+R14)<0; 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: 4.2<IH / EPD<6.3; the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the combined focal length f567 of the fifth lens, the sixth lens and the seventh lens satisfy: -1.65<f1234 / f567<-1.

1.

2. 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: 5.6<TTL / f<7; the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.2<TTL / IH<2.

7.

3. The optical lens of claim 1, wherein, The object side surface curvature radius R13 of the seventh lens and the image side surface curvature radius R14 of the seventh lens satisfy: -0.34<(R13-R14) / (R13+R14)<-0.2; 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: 4.63<IH / EPD<5.71; the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the combined focal length f567 of the fifth lens, the sixth lens and the seventh lens satisfy: -1.52<f1234 / f567<-1.

24.

4. The optical lens of claim 1, wherein, 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: 2.25<IH / f<3.1; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.5<BFL / f<0.

9.

5. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -5.5<f2 / f<-3.9; the effective focal length f of the optical lens and the object side surface curvature radius R3 of the second lens satisfy: 0.55<R3 / f<0.

75.

6. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f3 of the third lens satisfy: -2.75 < f3 / f < -2.1; a radius of curvature R5 on an object side of the third lens and the effective focal length f of the optical lens satisfy: -1.9 < R5 / f < -1.4; a radius of curvature R6 on an image side of the third lens and the effective focal length f of the optical lens satisfy: 5.7 < R6 / f < 7.

4.

7. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f4 of the fourth lens satisfy: 1.8 < f4 / f < 2.2; the effective focal length f of the optical lens and a radius of curvature R8 on an image side of the fourth lens satisfy: 12.9 < R8 / f < 53.

1.

8. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f6 of the sixth lens satisfy: -0.9 < f6 / f < -0.7; the effective focal length f of the optical lens and a radius of curvature R12 on an image side of the sixth lens satisfy: -3.5 < R12 / f < -2.

3.

9. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f7 of the seventh lens satisfy: 2.7 < f7 / f < 3.55; the effective focal length f of the optical lens and a radius of curvature R14 on an image side of the seventh lens satisfy: 1.4 < R14 / f < 2.

6.

10. The optical lens of claim 1, wherein, A radius of curvature R11 on an object side of the sixth lens and a radius of curvature R12 on an image side of the sixth lens satisfy: -1 < (R11-R12) / (R11+R12) < -0.5; a radius of curvature R5 on an object side of the third lens and a radius of curvature R6 on an image side of the third lens satisfy: -0.8 < (R5+R6) / (R5-R6) < -0.3.

Images