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 near the optical axis, and the image side surface of the second lens is a concave surface; a third lens with negative optical power, wherein the object side surface and the image side surface of the third lens are both concave surfaces; 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 concave surface; a fifth lens with positive optical power, wherein the object side surface and the image side surface of the fifth lens are both convex surfaces; a sixth lens with negative optical power, wherein the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a concave surface near the optical axis; and a seventh lens with positive optical power, wherein the object side surface of the seventh lens is a convex surface near the optical axis, and the image side surface of the seventh lens is a convex surface. The optical lens provided by the application has one or more advantages of a large aperture, a large field of view, high imaging quality and the like through specific surface shape matching and reasonable optical power distribution.

Description

Technical Field

[0001] This invention relates to the technical field of imaging lenses, and in particular to an optical lens. Background Technology

[0002] As people's demands for driving experience continue to increase, automotive optical lenses are being used more and more in intelligent driving, and the status of automotive optical lenses in the automotive industry is constantly rising.

[0003] Advanced Driver Assistance Systems (ADAS) play a crucial role in intelligent driving. They use various cameras and sensors to collect environmental information to ensure driver safety. For example, typically, a surround-view camera is installed in each of the four directions (front, rear, left, and right) of a vehicle. By stitching together the images captured by these four cameras, a 360-degree panoramic view of the vehicle's surroundings can be provided to the driver. With the rapid development of ADAS, the requirements for surround-view cameras are also increasing. Therefore, it is necessary to develop an optical lens with high imaging quality. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an optical lens with the advantage of excellent image quality.

[0005] The technical solution adopted in this invention is as follows:

[0006] An optical lens comprises seven lenses, arranged sequentially along the optical axis from the object side to the imaging plane:

[0007] The first lens with negative optical power has a convex object side and a concave image side.

[0008] A second lens with negative optical power has an object-side surface that is concave near the optical axis and an image-side surface that is concave.

[0009] A third lens with negative optical power has concave object-side and image-side surfaces;

[0010] The fourth lens with positive optical power has a convex object side and a concave image side.

[0011] The fifth lens with positive optical power has convex surfaces on both its object side and image side.

[0012] The sixth lens with negative optical power has a concave object side and a concave image side near the optical axis.

[0013] The seventh lens with positive optical power has an object-side surface that is convex near the optical axis and an image-side surface that is convex.

[0014] Among them, the radius of curvature R3 of the object side of the second lens and the radius of curvature R8 of the image side of the fourth lens satisfy: 1.1 <

[0015] (R3 - R8) / (R3 + R8) < 1.5.

[0016] More preferably, the radius of curvature R3 of the object side surface of the second lens, the radius of curvature R4 of the image side surface of the second lens, and the central thickness CT2 of the second lens satisfy: -20 < R3 / (R4 + CT2) < -15.

[0017] More preferably, the sagittal height Sag13 of the clear aperture on the object side surface of the seventh lens satisfies: 0 < Sag13 < 0.1 mm; the perpendicular distance YC13 from the anti - inflection point on the object side surface of the seventh lens to the optical axis and the clear aperture diameter d13 of the object side surface of the seventh lens satisfy: 0.6 < YC13 / d13 < 0.8.

[0018] More preferably, the maximum field angle FOV of the optical lens and the f - number FNO of the optical lens satisfy: FOV / FNO > 95°.

[0019] More preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -3.3 < f3 / f < -2.7; the radius of curvature R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: 8 < R6 / f < 9.2.

[0020] More preferably, the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the effective focal length f of the optical lens satisfy: -1.5 < f1234 / f < -1.1.

[0021] More preferably, the radius of curvature R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -40 < R3 / f < -30; the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: -25 < R3 / R4 < -15.

[0022] More preferably, the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 4 < R8 / f < 6; the sagittal height Sag8 of the clear aperture on the image side surface of the fourth lens and the clear aperture diameter d8 of the image side surface of the fourth lens satisfy: 0 < Sag8 / d8 < 0.2.

[0023] More preferably, the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 1.5 < R12 / f < 2.9; the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: -1.2 < R12 / R11 < -0.2.

[0024] Further preferably, the radius of curvature R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1.1 < R13 / f < 1.9; the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -2.2 < R14 / f < -1.7.

[0025] The optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberrations, improve the imaging quality of the optical lens, and endow the lens with one or more advantages such as a large aperture, a large field angle, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0027] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 2 is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 3 is an F-θ distortion curve diagram of the optical lens in Embodiment 1 of the present invention.

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

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

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

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

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

[0035] Figure 9 is an F-θ distortion curve diagram of the optical lens in Embodiment 2 of the present invention.

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

[0037] Figure 11 is a lateral chromatic aberration curve diagram of the optical lens in Embodiment 2 of the present invention.

[0038] Figure 12 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0039] Figure 13 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0040] Figure 14 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0041] Figure 15 This is the F-θ distortion curve of the optical lens in Embodiment 3 of the present invention.

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

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

[0044] Figure 18 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0045] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0046] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0047] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0048] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0049] In this article, "near the optical axis" refers to the region near the optical axis. If the lens surface is convex and its location is not defined, it means that the lens surface is convex at least near the optical axis; if the lens surface is concave and its location is not defined, it means that the lens surface is concave at least near the optical axis. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0050] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0051] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0052] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0053] The optical lens provided in this embodiment of the invention consists of seven lenses, which are arranged sequentially along the optical axis from the object side to the imaging plane as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

[0054] In some embodiments, the first lens may have negative optical power, with a convex object-side surface and a concave image-side surface. The second lens may have negative optical power, with a concave object-side surface near the optical axis and a concave image-side surface. The third lens may have negative optical power, with both its object-side and image-side surfaces concave. The fourth lens may have positive optical power, with a convex object-side surface and a concave image-side surface. The fifth lens may have positive optical power, with both its object-side and image-side surfaces convex. The sixth lens may have negative optical power, with a concave object-side surface and a concave image-side surface near the optical axis. The seventh lens may have positive optical power, with a convex object-side surface near the optical axis and a convex image-side surface.

[0055] In some embodiments, the optical lens may further include an aperture which may be located between the fourth lens and the fifth lens. It can be understood that the aperture can be used to limit the amount of incident light so as to change the brightness of the image. Additionally, when the aperture is located between the fourth lens and the fifth lens, the aperture can reasonably distribute the functions of the first lens to the seventh lens. For example, the first lens, the second lens, the third lens, and the fourth lens can be used to receive light to a large extent, and the fifth lens to the seventh lens can be used to correct aberration, which is beneficial to balancing the structure of the entire optical system. Furthermore, when the aperture is located between the fourth lens and the fifth lens, it is convenient to correct the aperture aberration.

[0056] In some embodiments, the optical lens may further include a filter and a protective glass. The filter and the protective glass may be sequentially arranged along the optical axis between the seventh lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging. The protective glass plays a role in protecting the optical lens, preventing the photosensitive chip from being damaged, and can improve the anti-impact and scratch-resistant capabilities of the optical lens, while having little impact on the imaging quality of the optical lens.

[0057] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 1.1 < (R3 - R8) / (R3 + R8) < 1.5. Meeting the above range, by reasonably defining the shapes of the object side surface of the second lens and the image side surface of the fourth lens, it helps to reduce the distortion of the optical lens and improve the imaging quality of the optical lens. Preferably, 1.3 < (R3 - R8) / (R3 + R8) < 1.4.

[0058] In some embodiments, the radius of curvature R3 of the object side surface of the second lens, the radius of curvature R4 of the image side surface of the second lens, and the central thickness CT2 of the second lens satisfy: -20 < R3 / (R4 + CT2) < -15. Meeting the above range, by reasonably controlling the shapes of the object side surface and the image side surface of the second lens and the central thickness of the second lens, it helps to meet the requirements of the processability and manufacturability of the optical lens. Preferably, -18 < R3 / (R4 + CT2) < -17.5.

[0059] In some embodiments, the sagittal height Sag13 of the clear aperture of the object side surface of the seventh lens satisfies: 0 < Sag13 < 0.1 mm; the perpendicular distance YC13 between the inflection point on the object side surface of the seventh lens and the optical axis and the clear aperture diameter d13 of the object side surface of the seventh lens satisfy: 0.6 < YC13 / d13 < 0.8. Meeting the above range, by reasonably controlling the sagittal height, clear aperture diameter, and inflection point height of the object side surface of the seventh lens, it helps to control the object side surface of the seventh lens to have an appropriate surface shape and improve the imaging quality of the edge field of view. Preferably, 0.65 < YC13 / d13 < 0.76.

[0060] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value FNO of the optical lens satisfy: FOV / FNO > 95°. Meeting the above range, by reasonably controlling the field of view angle and aperture value of the optical lens, it is beneficial to obtain the characteristics of a large field of view angle and a large aperture, facilitating the optical lens to obtain more scene information. Preferably, FOV / FNO > 98°.

[0061] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -3.3 < f3 / f < -2.7; the radius of curvature R6 of the image side of the third lens and the effective focal length f of the optical lens satisfy: 8 < R6 / f < 9.2. Meeting the above range, by controlling the third lens to have an appropriate negative optical power, it helps to increase the imaging area and improve the imaging quality. Reasonably limiting the radius of curvature of the image side of the third lens and the focal length of the optical lens helps to reduce distortion and improve the imaging quality. Preferably, -3.3 < f3 / f < -2.9, 8.4 < R6 / f < 8.8.

[0062] In some embodiments, the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the effective focal length f of the optical lens satisfy: -1.5 < f1234 / f < -1.1. Meeting the above range, by controlling the front lens group to have an appropriate negative optical power, it helps to collect the light rays in the edge field of view and increase the image plane. Preferably, -1.5 < f1234 / f < -1.2.

[0063] In some embodiments, the radius of curvature R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: -40 < R3 / f < -30; the radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: -25 < R3 / R4 < -15. Meeting the above range, by reasonably limiting the shapes of the object side and the image side of the second lens and the focal length of the optical lens, it helps to reduce field curvature and improve the imaging quality of the optical lens. Preferably, -39 < R3 / f < -36, -22 < R3 / R4 < -20.

[0064] In some embodiments, the radius of curvature R8 of the image side of the fourth lens and the effective focal length f of the optical lens satisfy: 4 < R8 / f < 6; the sagittal height Sag8 of the image side clear aperture of the fourth lens and the clear aperture d8 of the image side of the fourth lens satisfy: 0 < Sag8 / d8 < 0.2. Meeting the above range, by reasonably limiting the radius of curvature, sagittal height, clear aperture of the image side of the fourth lens and the focal length of the optical lens, it helps to correct aberration, while improving the imaging quality of the edge field of view and highlighting the detailed information of the central field of view of the optical lens. Preferably, 5.1 < R8 / f < 5.4, 0.05 < Sag8 / d8 < 0.12.

[0065] In some embodiments, the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 1.5 < R12 / f < 2.9; the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: -1.2 < R12 / R11 < -0.2. Satisfying the above ranges, by reasonably defining the shapes of the object side surface and the image side surface of the sixth lens and the focal length of the optical lens, it helps to reduce coma and improve the imaging quality. Preferably, 1.6 < R12 / f < 2.5, -1.1 < R12 / R11 < -0.5.

[0066] In some embodiments, the radius of curvature R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1.1 < R13 / f < 1.9; the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -2.2 < R14 / f < -1.7. Satisfying the above ranges, by reasonably defining the shapes of the object side surface and the image side surface of the seventh lens and the focal length of the optical lens, it helps to reduce aberration, increase the image plane, and improve the imaging quality. Preferably, 1.2 < R13 / f < 1.85, -2.1 < R14 / f < -1.9.

[0067] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 12 < TTL / f < 14. Satisfying the above ranges, by controlling the overall optical length and the focal length of the optical lens within a suitable range, it ensures that there is enough space to adjust each lens structure and improve the imaging quality. Preferably, 12.5 < TTL / f < 13.5.

[0068] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 6.5 < IH / EPD < 8.5. Satisfying the above ranges, by reasonably controlling the relationship between the image height and the entrance pupil diameter, it helps to increase the width of the light beam entering the optical lens, improve the relative illuminance of the edge field of view, and enhance the imaging quality. Preferably, 6.7 < IH / EPD < 7.9.

[0069] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: BFL / f > 2.4. Satisfying the above ranges, by reasonably controlling the optical lens to have a suitable back focal length, it helps to reasonably arrange each lens in the optical lens, reduce the assembly difficulty, and improve the yield. Preferably, BFL / f > 2.45.

[0070] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -5.9 < f1 / f < -4.9. Meeting the above range, by controlling the first lens to have an appropriate negative optical power, it helps to achieve large-angle light collection and achieve the characteristic of a large field angle. Preferably, -5.9 < f1 / f < -5.5.

[0071] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.5 < f2 / f < -3. Meeting the above range, by controlling the second lens to have an appropriate negative optical power, it helps to share the negative optical power of the front lens, avoid large light deflection caused by concentrated optical power, and improve the imaging quality. Preferably, -3.3 < f2 / f < -3.

[0072] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 3.4 < f4 / f < 3.8. Meeting the above range, by controlling the fourth lens to have an appropriate positive optical power, it helps to converge light and improve the imaging quality of the edge field of view. Preferably, 3.4 < f4 / f < 3.6.

[0073] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 1.9 < f5 / f < 2.4. Meeting the above range, by controlling the fifth lens to have an appropriate positive optical power, it helps to further converge the light of the edge field angle and improve the relative illumination of the lens. Preferably, 1.9 < f5 / f < 2.3.

[0074] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -2 < f6 / f < -1.5. Meeting the above range, by controlling the sixth lens to have an appropriate negative optical power, it helps to reduce the field curvature and improve the imaging quality. Preferably, -1.9 < f6 / f < -1.5.

[0075] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.4 < f7 / f < 2.1. Meeting the above range, by controlling the seventh lens to have an appropriate positive optical power, it helps to optimize spherical aberration and can effectively transmit more light beams to the image plane, improving the imaging quality. Preferably, 1.6 < f7 / f < 2.1.

[0076] In some embodiments, the fifth lens and the sixth lens form a cemented lens group with positive optical power, and the image side surface of the fifth lens and the object side surface of the sixth lens are cemented surfaces. 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 < f56 / f < 9. Meeting the above range and controlling the cemented lens formed by the fifth lens and the sixth lens to have an appropriate positive optical power helps to reduce chromatic aberration and improve imaging quality. Preferably, 4.6 < f56 / f < 8.5.

[0077] 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: -0.6 < f1234 / f567 < -0.4. Meeting the above range and controlling the optical powers of the front lens group and the rear lens group within a suitable range helps to control the reasonable distribution of the optical powers of the lenses of the optical lens and improve the structural stability of the optical lens. Preferably, -0.6 < f1234 / f567 < -0.5.

[0078] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the focal length f2 of the second lens satisfy: 10 < R3 / f2 < 14. Meeting the above range and reasonably defining the shape of the object side surface of the second lens and the focal length of the second lens can reduce the difficulty of aberration correction of the subsequent lenses and improve the imaging quality. Preferably, 11.5 < R3 / f2 < 12.5.

[0079] In some embodiments, the radius of curvature R8 of the image side surface of the fourth lens and the focal length f4 of the fourth lens satisfy: 1.2 < R8 / f4 < 1.7. Meeting the above range and reasonably defining the shape of the image side surface of the fourth lens and the focal length of the fourth lens can control the smooth trend of light rays and improve the imaging quality. Preferably, 1.4 < R8 / f4 < 1.5.

[0080] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: 0.8 < (R3 + R4) / (R3 - R4) < 1. Meeting the above range and reasonably defining the shapes of the object side surface and the image side surface of the second lens helps to further reduce field curvature and improve the imaging quality. Preferably, 0.9 < (R3 + R4) / (R3 - R4) < 1.

[0081] In some embodiments, the central thickness CT2 of the second lens and the edge thickness ET2 of the second lens satisfy: 2.5 < CT2 / ET2 < 3. Meeting the above range and reasonably controlling the edge thickness ratio of the second lens can reduce the processing difficulty of the second lens and effectively correct the aberration of the edge field at the same time. Preferably, 2.55 < CT2 / ET2 < 2.70.

[0082] In some embodiments, the optical lens satisfies the following condition: 1.3mm <f<1.8mm;FOV> 190°; EPD < 0.9mm; 18mm <TTL<21mm;1.6<FNO<2.2;5.4mm<IH<6mm;12°<CRA<17°;BFL> 3.5mm. In the above conditional formula, f represents the effective focal length of the optical lens, FOV represents the maximum field of view of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, FNO represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field of view of the optical lens, CRA represents the principal ray incident angle at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above range, the optical lens possesses at least one or more advantages such as a large target surface, a large aperture, and a large field of view. Preferably, the optical lens meets the following conditional formula: 1.4mm <f<1.6mm;FOV> 198°; 0.7mm <EPD<0.9mm;18.5mm<TTL<20.5mm;1.8<FNO<2.1;5.4mm<IH<5.8mm;13.5°<CRA<16°;BFL> 3.7mm.

[0083] In some embodiments, the first, second, third, fourth, fifth, sixth, and seventh lenses can be spherical or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce the aberrations of the optical system, thereby reducing the number of lenses and their size, and better achieving lens miniaturization. More specifically, the first and fourth lenses of this invention are spherical lenses, while the second, third, fifth, sixth, and seventh lenses are aspherical lenses.

[0084] In various embodiments of the present invention, when an aspherical lens is used, the shapes of each aspherical surface of the optical lens satisfy the following equations:

[0085]

[0086] Where z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the quadratic surface coefficient, and B, C, D, E, F, G, and I are the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order surface coefficients, respectively.

[0087] The present invention will be further described below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different; for specific differences, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

[0088] Example 1

[0089] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1, and a protective glass G2.

[0090] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0091] The second lens L2 has negative optical power, its object side S3 is concave near the optical axis, and its image side S4 is concave.

[0092] The third lens L3 has negative optical power, and its object side S5 and image side S6 are both concave.

[0093] The fourth lens L4 has positive optical power, its object side S7 is convex, and its image side S8 is concave.

[0094] The fifth lens L5 has positive optical power, and both its object side S9 and image side S10 are convex surfaces;

[0095] The sixth lens L6 has negative optical power, its object side S10 is concave near the optical axis, and its image side S11 is concave.

[0096] The fifth lens L5 and the sixth lens L6 form a cemented lens group with positive optical 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.

[0097] The seventh lens L7 has positive optical power, its object side surface S12 is convex, and its image side surface S13 is concave.

[0098] The object-side surface S14 and the image-side surface S15 of filter G1 are both planar.

[0099] The object side S16 and the image side S17 of the protective glass G2 are both flat.

[0100] The imaging plane S18 is a plane.

[0101] The first lens L1 and the fourth lens L4 are glass spherical lenses, while the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are plastic aspherical lenses.

[0102] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0103] Table 1-1

[0104]

[0105] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0106] Table 1-2

[0107] Face number K B C D E F G I S3 1.99E+02 6.32E-03 -8.25E-04 8.10E-05 -4.21E-06 9.32E-08 0.00E+00 0.00E+00 S4 3.04E-02 -7.00E-03 1.68E-03 -1.02E-03 1.87E-04 -1.37E-05 0.00E+00 0.00E+00 S5 3.22E-01 -2.33E-02 1.26E-02 -1.92E-03 1.33E-04 -6.05E-07 0.00E+00 0.00E+00 S6 3.42E+01 -1.94E-02 9.64E-03 -1.70E-03 1.76E-04 -9.83E-06 0.00E+00 0.00E+00 S9 -3.22E-01 6.32E-03 -8.25E-04 8.10E-05 -4.21E-06 9.32E-08 0.00E+00 0.00E+00 S10 7.13E+00 -2.63E-02 8.96E-03 -5.94E-03 1.77E-03 -1.63E-05 1.05E-04 -8.60E-05 S11 -3.29E+01 -2.00E-01 1.33E-01 -8.74E-02 3.55E-02 -6.26E-03 -8.04E-04 4.04E-04 S12 -1.66E+01 -4.18E-02 1.34E-02 -2.72E-03 7.08E-04 -3.48E-04 8.05E-05 -5.71E-06 S13 -4.25E+00 -2.67E-02 3.51E-03 -1.23E-04 1.79E-05 -7.06E-05 4.31E-08 2.36E-06

[0108] In this embodiment, the field curvature curve, F-θ distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown.

[0109] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.03 mm to 0.04 mm, indicating that the optical lens can effectively correct the field curvature.

[0110] Figure 3 The F-θ distortion curve of Example 1 is shown, which represents the F-θ distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-θ distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-θ distortion of the optical lens is controlled within 0 to 8%, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0111] Figure 4 The axial aberration curve of Example 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial aberration offset is controlled within -0.01 mm to 0.04 mm, indicating that the optical lens can correct axial aberration well.

[0112] Figure 5 The diagram shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.546 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -2 μm to 2 μm, indicating that the optical lens can excellently correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0113] Figure 6 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.3 throughout the entire field of view. Within the range of 0–160 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0114] Example 2

[0115] Please see Figure 7 The figure shown is a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0116] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0117] Table 2-1

[0118]

[0119]

[0120] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0121] Table 2-2

[0122] Face number K B C D E F G I S3 2.00E+02 5.61E-03 -8.66E-04 9.10E-05 -4.77E-06 1.02E-07 0.00E+00 0.00E+00 S4 -3.62E-01 -4.50E-03 1.60E-03 -1.04E-03 2.07E-04 -1.34E-05 0.00E+00 0.00E+00 S5 6.31E-01 -2.83E-02 1.39E-02 -1.99E-03 1.09E-04 2.84E-06 0.00E+00 0.00E+00 S6 3.43E+01 -2.40E-02 1.11E-02 -1.81E-03 1.45E-04 -3.89E-06 0.00E+00 0.00E+00 S9 -3.78E-01 -2.56E-02 7.23E-03 -5.01E-03 1.82E-03 8.82E-05 -1.56E-04 -7.41E-06 S10 4.26E+00 -1.78E-01 1.34E-01 -8.23E-02 3.11E-02 -4.33E-03 -1.32E-03 4.90E-04 S11 -3.57E+01 -2.81E-02 1.11E-02 -2.70E-03 6.75E-04 -3.48E-04 9.60E-05 -8.44E-06 S12 -1.29E+01 -2.29E-02 4.10E-03 -1.09E-03 1.45E-04 -4.90E-05 -7.01E-06 2.91E-06 S13 -4.85E+00 -1.33E-02 -7.26E-04 5.67E-04 -1.43E-04 5.02E-06 1.46E-06 -1.43E-07

[0123] In this embodiment, the field curvature curve, F-θ distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 200 are respectively as follows: Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 As shown. From Figure 8 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.03mm to 0.03mm, indicating that the optical lens 200 can effectively correct field curvature. From Figure 9 As can be seen, the F-θ distortion of the 200mm optical lens is controlled within 0-6%, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image. From Figure 10 As can be seen, the axial aberration offset is controlled within -0.01mm to 0.03mm, indicating that the optical lens 200 can effectively correct axial aberration. From Figure 11 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -2 to 2 μm, indicating that the optical lens 200 can excellently correct chromatic aberration at the edge of the field of view and the second-order spectrum of the entire image plane. From Figure 12 As can be seen, the MTF value of this embodiment is above 0.35 throughout the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0124] Example 3

[0125] Please see Figure 13 The figure shown is a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0126] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0127] Table 3-1

[0128]

[0129] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0130] Table 3-2

[0131] Face number K B C D E F G I S3 2.00E+02 5.66E-03 -8.66E-04 9.10E-05 -4.77E-06 1.03E-07 0.00E+00 0.00E+00 S4 -3.62E-01 -5.10E-03 1.72E-03 -1.06E-03 2.06E-04 -1.33E-05 0.00E+00 0.00E+00 S5 6.31E-01 -2.83E-02 1.38E-02 -1.99E-03 1.09E-04 2.96E-06 0.00E+00 0.00E+00 S6 3.43E+01 -2.36E-02 1.09E-02 -1.82E-03 1.45E-04 -6.41E-06 0.00E+00 0.00E+00 S9 -3.46E-01 -2.53E-02 7.12E-03 -5.00E-03 1.89E-03 -3.20E-06 -3.45E-04 1.14E-04 S10 4.02E+00 -1.73E-01 1.36E-01 -8.28E-02 3.07E-02 -3.90E-03 -1.02E-03 3.63E-04 S11 -3.74E+01 -2.77E-02 1.11E-02 -2.65E-03 7.00E-04 -3.44E-04 9.60E-05 -8.27E-06 S12 -1.46E+01 -2.36E-02 4.05E-03 -1.07E-03 1.50E-04 -4.69E-05 -5.92E-06 3.56E-06 S13 -4.23E+00 -1.35E-02 -7.52E-04 5.73E-04 -1.41E-04 5.54E-06 1.48E-06 -1.42E-07

[0132] In this embodiment, the field curvature curve, F-θ distortion curve, axial aberration curve, transverse chromatic aberration curve, MTF curve, and relative illumination curve of the optical lens 300 are respectively as follows: Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 As shown. From Figure 14As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.03mm to 0.05mm, indicating that the optical lens 300 can effectively correct field curvature. Figure 15 As can be seen, the F-θ distortion of the 300mm optical lens is controlled within 0-10%, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image. From Figure 16 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.02mm, indicating that the optical lens 300 can effectively correct axial aberration. From Figure 17 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 2μm, indicating that the optical lens 300 can excellently correct chromatic aberration at the edge of the field of view and the second-order spectrum of the entire image plane. From Figure 18 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0133] 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, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0134] Table 4

[0135]

[0136]

[0137] In summary, the optical lens provided by the present invention employs seven lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as large aperture, large field of view, and high imaging quality.

[0138] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0139] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens comprising seven lenses, characterized in that, It successively includes from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side is convex and whose image side is concave; A second lens with a negative optical power, whose object side is concave near the optical axis and whose image side is concave; A third lens with a negative optical power, whose object side and image side are both concave; A fourth lens with a positive optical power, whose object side is convex and whose image side is concave; A fifth lens with a positive optical power, whose object side and image side are both convex; A sixth lens with a negative optical power, whose object side is concave and whose image side is concave near the optical axis; A seventh lens with a positive optical power, whose object side is convex near the optical axis and whose image side is convex; Wherein, the radius of curvature R3 of the object side of the second lens and the radius of curvature R8 of the image side of the fourth lens satisfy: 1.1 < (R3 - R8) / (R3 + R8) < 1.5; The true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 6.5 < IH / EPD < 8.

5.

2. The optical lens according to claim 1, characterized in that, The radius of curvature R3 of the object side of the second lens, the radius of curvature R4 of the image side of the second lens, and the central thickness CT2 of the second lens satisfy: -20 < R3 / (R4 + CT2) < -15.

3. The optical lens according to claim 1, characterized in that, The sagittal height Sag13 of the clear aperture radius of the object side of the seventh lens satisfies: 0 < Sag13 < 0.1 mm; the vertical distance YC13 between the inflection point on the object side of the seventh lens and the optical axis and the clear aperture diameter d13 of the object side of the seventh lens satisfy: 0.6 < YC13 / d13 < 0.

8.

4. The optical lens according to claim 1, characterized in that, The maximum field angle FOV of the optical lens and the f-number FNO of the optical lens satisfy: 95° < FOV / FNO ≤ 108.7°; The radius of curvature R3 of the object side of the second lens and the radius of curvature R8 of the image side of the fourth lens satisfy: 1.32 ≤ (R3 - R8) / (R3 + R8) ≤ 1.33; The true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 6.76 ≤ IH / EPD ≤ 7.

83.

5. The optical lens according to claim 1, characterized in that, The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -3.3 < f3 / f < -2.7; the radius of curvature R6 of the image side of the third lens and the effective focal length f of the optical lens satisfy: 8 < R6 / f < 9.

2.

6. The optical lens according to claim 1, characterized in that, The combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the effective focal length f of the optical lens satisfy: -1.5 < f1234 / f < -1.

1.

7. The optical lens according to claim 1, characterized in that, The radius of curvature R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: -40 < R3 / f < -30; the radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: -25 < R3 / R4 < -15.

8. The optical lens according to claim 1, characterized in that, The radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 4 < R8 / f < 6; the sagittal height Sag8 of the image side surface of the fourth lens and the clear aperture semi-diameter d8 of the image side surface of the fourth lens satisfy: 0 < Sag8 / d8 < 0.

2.

9. The optical lens according to claim 1, characterized in that, The radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 1.5 < R12 / f < 2.9; the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: -1.2 < R12 / R11 < -0.

2.

10. The optical lens according to claim 1, characterized in that, The radius of curvature R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1.1 < R13 / f < 1.9; the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -2.2 < R14 / f < -1.7.

Images