Optical lens

Abstract

The invention provides an optical lens, which comprises seven lenses in total, and sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power from an object side to an imaging surface, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a concave surface; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has positive focal power, and the object side surface of the fifth lens is a convex surface; the sixth lens has negative focal power; and the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a concave surface. According to the optical lens provided by the invention, the imaging quality of the optical lens can be improved, the aberration can be reduced, the imaging quality of the optical lens can be improved, and the lens has one or more advantages of large target surface, large aperture, high imaging quality and the like.

Description

Technical Field

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

[0002] As people's requirements for driving experience continue to increase, automotive optical lenses are increasingly used in intelligent driving, and the status of automotive optical lenses in the automotive-related industries continues to improve.

[0003] Advanced Driver Assistance Systems (ADAS) play a crucial role in intelligent driving. They use various lenses and sensors to collect environmental information to ensure driver safety. Existing ADAS systems require not only a thin, compact form factor with high pixel count and resolution, but also the ability to produce clear images in low-light conditions. Therefore, developing an optical lens with excellent imaging performance is crucial. Summary of the Invention

[0004] In view of the above problems, an object of the present invention is to provide an optical lens having the advantage of excellent imaging quality.

[0005] The technical solution adopted in the present invention is:

[0006] An optical lens, comprising seven lenses, including the following elements in order from the object side to the imaging surface along the optical axis:

[0007] The first lens has a negative optical power, its object-side surface is concave, and its image-side surface is convex;

[0008] a second lens having positive refractive power, whose object-side surface is convex and whose image-side surface is concave;

[0009] a third lens element having negative optical power, whose object-side surface and image-side surface are concave;

[0010] a fourth lens element having positive refractive power, whose object-side surface is convex and whose image-side surface is convex;

[0011] a fifth lens element having positive optical power and a convex object-side surface;

[0012] a sixth lens having negative optical power;

[0013] a seventh lens element having positive refractive power, whose object-side surface is convex and whose image-side surface is concave;

[0014] The focal length f1 of the first lens and the focal length f3 of the third lens satisfy: 1.8 <f1 / f3<2.6;

[0015] The radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: -1 < (R5 + R6) / (R5 - R6) < -0.75.

[0016] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.3 < TTL / f < 4.8; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 4 < TTL / IH < 4.6.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -4.8 < f1 / f < -4.4; the radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -3 < R1 / f < -2.3; the radius of curvature R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: -41 < R2 / f < -39.

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 5.3 < f2 / f < 6.1; 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: 2 < R3 / f < 5; the radius of curvature R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 3 < R4 / f < 30.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -2.5 < f3 / f < -1.8; the radius of curvature R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: -1.7 < R5 / f < -1.3; 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: 10 < R6 / f < 42.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.7 < f4 / f < 2.2; the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 1 < R7 / f < 2; 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: -70 < R8 / f < -3.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.8 < f7 / f < 12.5; 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: 0.7 < R13 / f < 1.3; 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: 0.9 < R14 / f < 1.3.

[0022] Further preferably, the effective focal length f of the optical lens and the combined focal length f123 of the first lens, the second lens and the third lens satisfy: -2 < f123 / f < -1.6; the effective focal length f of the optical lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: 0.8 < f4567 / f < 1.

[0023] Further preferably, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -1.4 < f3 / f4 < -0.8; the radius of curvature R6 of the image side surface of the third lens and the radius of curvature R7 of the object side surface of the fourth lens satisfy: 8 < R6 / R7 < 36.

[0024] Further preferably, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: -0.9 < (R1 - R2) / (R1 + R2) < -0.85; the central thickness CT1 of the first lens and the central thickness CT2 of the second lens satisfy: 5 < CT1 / CT2 < 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 aberration, improve the imaging quality of the optical lens, and endow the lens with one or more advantages such as a large target surface, a large aperture, 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 following description of the embodiments in conjunction with the accompanying 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-Tan(Theta) distortion curve diagram of the optical lens in Embodiment 1 of the present invention.

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

[0031] Figure 5 Graph showing the vertical axis chromatic aberration of the optical lens in Example 1 of the present invention.

[0032] Figure 6 This is the MTF curve of the optical lens in Example 1 of the present invention.

[0033] Figure 7 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0034] Figure 8 Graph showing the field curvature of the optical lens in Example 2 of the present invention.

[0035] Figure 9 FIG. 4 is a graph showing the F-Tan (Theta) distortion curve of the optical lens in Example 2 of the present invention.

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

[0037] Figure 11 Graph showing vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

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

[0039] Figure 13 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0040] Figure 14 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0041] Figure 15 Graph showing the F-Tan (Theta) distortion of the optical lens in Example 3 of the present invention.

[0042] Figure 16 4 is an axial aberration curve diagram of the optical lens in Example 3 of the present invention.

[0043] Figure 17 Graph showing vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

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

[0045] Figure 19 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0046] Figure 204 is a field curvature curve diagram of the optical lens in Example 4 of the present invention.

[0047] Figure 21 Graph showing the F-Tan (Theta) distortion of the optical lens in Example 4 of the present invention.

[0048] Figure 22 4 is an axial aberration curve diagram of the optical lens in Example 4 of the present invention.

[0049] Figure 23 Graph showing vertical axis chromatic aberration of the optical lens in Example 4 of the present invention.

[0050] Figure 24 This is the MTF curve of the optical lens in Example 4 of the present invention.

[0051] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0052] 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 should be understood that these detailed descriptions are merely descriptions of embodiments of the present application and are not intended to limit the scope of the present 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.

[0053] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of the present invention.

[0054] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0055] In this article, the paraxial region refers to the area near the optical axis. If a lens surface is convex and the location of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the location of the concave surface is undefined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0056] It should also be understood that the terms "comprises," "including," "having," "includes," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application." And, the term "exemplary" is intended to refer to an example or illustration.

[0057] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0058] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0059] The optical lens provided in an embodiment of the present invention comprises seven lenses, which are arranged in order from the object side to the imaging surface along the optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

[0060] In some embodiments, the first lens may have negative optical power, its object-side surface is concave, and its image-side surface is convex. The second lens may have positive optical power, its object-side surface is convex, and its image-side surface is concave. The third lens may have negative optical power, its object-side surface is concave, and its image-side surface is concave. The fourth lens may have positive optical power, its object-side surface is convex, and its image-side surface is convex. The fifth lens may have positive optical power, its object-side surface is convex, and its image-side surface may be concave or convex. The sixth lens may have negative optical power, its object-side surface may be concave or convex, and its image-side surface may be concave or convex. The seventh lens may have positive optical power, its object-side surface is convex, and its image-side surface is concave.

[0061] In some embodiments, the optical lens may further include an aperture, which may be located between the third and fourth lens elements. It is understood that the aperture is used to limit the amount of light entering, thereby changing the brightness of the image. When the aperture is located between the third and fourth lens elements, it facilitates correction of aperture aberrations.

[0062] In some embodiments, the optical lens may further include a filter and a protective glass, which are sequentially arranged between the seventh lens and the imaging surface along the optical axis. The filter is used to filter out interfering light to prevent it 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 impact resistance and scratch resistance of the optical lens, while having almost no impact on the imaging quality of the optical lens.

[0063] In some embodiments, the fifth lens and the sixth lens may be glued together to form a glued lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; it 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.

[0064] In some embodiments, the focal length f1 of the first lens and the focal length f3 of the third lens satisfy: 1.8 < f1 / f3 < 2.6. Meeting the above range, by reasonably setting the focal length relationship between the first and third lenses, it is beneficial to the smooth transition of light, and at the same time correct various aberrations of the optical lens, improving the imaging quality of the optical lens. More specifically, 1.84 < f1 / f3 < 2.51.

[0065] In some embodiments, the object-side curvature radius R5 of the third lens and the image-side curvature radius R6 of the third lens satisfy: -1 < (R5 + R6) / (R5 - R6) < -0.75. Meeting the above range, the third lens is a double concave type, which has the function of diverging light, can disperse the central light and marginal light of each field of view, and can correct the aberration generated by the front-end lens. More specifically, -0.94 < (R5 + R6) / (R5 - R6) < -0.78.

[0066] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.3 < TTL / f < 4.8. Meeting the above range can effectively limit the length of the lens, which is beneficial to the miniaturization of the optical lens. More specifically, 4.41 < TTL / f < 4.69.

[0067] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 4 < TTL / IH < 4.6. Meeting the above range, when ensuring the same overall length of the lens, it has a larger image plane, can match a larger-sized imaging chip to achieve high-definition imaging, and better achieve the balance between the small overall length and the large image plane of the lens. More specifically, 4.18 < TTL / IH < 4.43.

[0068] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -4.8 < f1 / f < -4.4; the radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -3 < R1 / f < -2.3; the radius of curvature R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: -41 < R2 / f < -39. Meeting the above ranges, by setting the first lens to have a negative refractive power and a suitable surface shape, it is beneficial for the first lens to accommodate a larger angle of light and collect as much light as possible into the rear optical system, increasing the light flux while achieving a large field of view. More specifically, -4.72 < f1 / f < -4.41; -2.75 < R1 / f < -2.55; -40.8 < R2 / f < -39.57.

[0069] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 5.3 < f2 / f < 6.1; 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: 2 < R3 / f < 5; the radius of curvature R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 3 < R4 / f < 30. Meeting the above ranges, by defining the second lens to have an appropriate positive optical power and a suitable surface shape, it has the effect of converging light, reducing the height of peripheral light, and is beneficial for reducing the aperture of the rear lens. More specifically, 5.31 < f2 / f < 6.1; 2.03 < R3 / f < 4.79; 3.17 < R4 / f < 28.42.

[0070] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -2.5 < f3 / f < -1.8; the radius of curvature R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: -1.7 < R5 / f < -1.3; 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: 10 < R6 / f < 42. Meeting the above ranges, it has the effect of diverging light, dispersing the central light and edge light of each field of view, enabling the rear optical system to have a larger light receiving surface to receive the light emerging from the image side surface of the third lens, achieving a larger light input, and being beneficial for increasing the relative illuminance. More specifically, -2.45 < f3 / f < -1.87; -1.59 < R5 / f < -1.42; 11.93 < R6 / f < 40.8.

[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.7 < f4 / f < 2.2; the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 1 < R7 / f < 2; the curvature radius R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -70 < R8 / f < -3. Satisfying the above ranges is beneficial to the convergence of light, enabling the divergent light to smoothly enter the rear optical system and better achieving high-quality imaging of the lens; at the same time, it can effectively correct the distortion of the edge field of view, reduce the degree of deformation of the edge of the captured image, and improve the image quality. More specifically, 1.71 < f4 / f < 2.16; 1.15 < R7 / f < 1.86; -69.04 < R8 / f < -3.13.

[0072] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.8 < f7 / f < 12.5; the curvature radius R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 0.7 < R13 / f < 1.3; the curvature radius R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 0.9 < R14 / f < 1.3. Satisfying the above ranges defines that the seventh lens has a positive optical power and a suitable surface shape, which is beneficial to the convergence of light, enables the light trend to smoothly transition to the rear, reduces the height of the light incident on the rear, slows down the upward trend of the light, and avoids the light energy loss caused by the excessive main ray angle of the large field of view light when reaching the imaging surface, which is beneficial to improving the illuminance of the edge field of view and is beneficial to achieving a short overall optical length. More specifically, 1.81 < f7 / f < 12.09; 0.76 < R13 / f < 1.18; 0.94 < R14 / f < 1.21.

[0073] In some embodiments, the effective focal length f of the optical lens and the combined focal length f123 of the first lens, the second lens and the third lens satisfy: -2 < f123 / f < -1.6; the effective focal length f of the optical lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: 0.8 < f4567 / f < 1. Satisfying the above ranges is beneficial to balancing various aberrations of the system and improving the overall imaging quality by reasonably setting the focal lengths of the lens groups before and after the aperture. More specifically, -1.98 < f123 / f < -1.62; 0.81 < f4567 / f < 0.92.

[0074] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -1.4 < f3 / f4 < -0.8; the image-side curvature radius R6 of the third lens and the object-side curvature radius R7 of the fourth lens satisfy: 8 < R6 / R7 < 36. Satisfying the above ranges and reasonably setting the focal length relationship and surface shape relationship of the lenses before and after the aperture can avoid excessive light deflection and reduce the difficulty of aberration correction. More specifically, -1.39 < f3 / f4 < -0.87; 8.5 < R6 / R7 < 34.62.

[0075] In some embodiments, the object-side curvature radius R1 of the first lens and the image-side curvature radius R2 of the first lens satisfy: -0.9 < (R1 - R2) / (R1 + R2) < -0.85. Satisfying the above range can make the collected light enter the rear optical system in a divergent form as much as possible, and at the same time effectively reduce the angle between the light incident on the edge field of view and the object side of the first lens, improving the overall relative illumination of the edge of the lens. More specifically, -0.89 < (R1 - R2) / (R1 + R2) < -0.86.

[0076] The central thickness CT1 of the first lens and the central thickness CT2 of the second lens satisfy: 5 < CT1 / CT2 < 7. Satisfying the above range, by reasonably setting the thicknesses of the first lens and the second lens, it is beneficial to adjust the light distribution, make the light pass through the lens more smoothly, is beneficial to the control of lens distortion, and makes the lens have less distortion. More specifically, 5.36 < CT1 / CT2 < 6.35.

[0077] 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: 1.7 < IH / EPD < 2.7. Satisfying the above range is beneficial to increasing the light transmission amount and making the brightness of the peripheral field of view and the central field of view more uniform. More specifically, 1.78 < IH / EPD < 1.92.

[0078] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1 < IH / f < 1.2. Satisfying the above range and controlling the image height and focal length of the optical lens within a reasonable range helps the optical lens to have the characteristic of a large image plane and improve the imaging quality. More specifically, 1.05 < IH / f < 1.12.

[0079] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.48 < BFL / f < 0.51. Satisfying the above range limits the optical lens to have an appropriate back focus, facilitates the reasonable arrangement of the positions of each lens, and at the same time reduces the processing and assembly difficulty.

[0080] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis satisfy: 0.77 < ∑CT / TTL < 0.8. Meeting the above range and reasonably configuring the total optical length of the optical lens and the sum of the thicknesses of each lens helps to achieve high pixel characteristics and improve the imaging quality of the optical lens.

[0081] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis and the effective focal length f of the optical lens satisfy: 3.49 < ΣCT / f < 3.69. Meeting the above range can effectively correct the field curvature and distortion of the optical lens and improve the imaging quality of the optical lens.

[0082] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1 < f5 / f < 1.6. Meeting the above range defines that the fifth lens has an appropriate positive optical power, which is beneficial to the convergence of light rays. By combining the fifth lens with a positive optical power and the sixth lens with a negative optical power, the optical path difference between different fields of view can be adjusted, the resolution can be improved, and it is beneficial for the light rays to enter the rear lens smoothly. Further, the field curvature can be reduced and the off-axis aberration of the optical lens can be corrected. More specifically, 1.06 < f5 / f < 1.52.

[0083] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.7 < f6 / f < -0.9. Meeting the above range defines that the sixth lens has an appropriate negative optical power, which can diverge the light rays emitted by the fifth lens, making the light rays in the edge field of view show an upward trend, which is beneficial for the image points on the imaging surface to be away from the optical axis, so as to achieve the effect of matching with a large chip, obtain a larger picture, effectively eliminate aberration, and improve the resolution ability of the optical lens. More specifically, -1.6 < f6 / f < -0.97.

[0084] In some embodiments, the optical lens satisfies the following conditional expressions: 7.2 mm < f < 7.7 mm; 4 mm < EPD < 4.6 mm; 32 mm < TTL < 37 mm; 1.6 < Fno < 1.9; 30° < CRA < 32°; 3.5 mm < BFL < 4 mm; 60° < FOV < 70°; 7.5 mm < IH < 8.5 mm. In the above conditional expressions, f represents the effective focal length 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, CRA represents the chief ray angle of incidence of the optical lens, BFL represents the back focal length of the optical lens, FOV represents the maximum field angle of the optical lens, and IH represents the true image height corresponding to the maximum field angle of the optical lens. Meeting the above ranges, the optical lens has at least one or more advantages such as a large target surface, a large aperture, and a long focal length characteristic. More specifically, 7.35 mm < f < 7.59 mm; 4.19 mm < EPD < 4.47 mm; 33.53 mm < TTL < 35.38 mm; 1.69 < Fno < 1.81; 30.47° < CRA < 31.32°; 3.66 mm < BFL < 3.75 mm; 63° < FOV < 69°; 7.99 mm < IH < 8.21 mm.

[0085] In some embodiments, the lens material of the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. On the other hand, when the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present invention can adopt an all-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

[0086] 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 spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens of the present invention adopt spherical lenses, and the seventh lens adopts an aspherical lens.

[0087] In various embodiments of the present invention, when the lens adopts an aspherical lens, the surface shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0088]

[0089] Where z is the distance between the surface and the vertex in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the surface vertex, K is the quadratic surface coefficient, and B, C, D, E, and F are the fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order surface coefficients, respectively.

[0090] The present invention is further illustrated below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens vary; for details, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any other changes, substitutions, combinations, or simplifications that do not deviate from the novelties of the present invention shall be considered equivalent replacements and are included within the scope of protection of the present invention.

[0091] Example 1

[0092] See also Figure 1 , shown is a schematic structural diagram of the optical lens 100 provided in Example 1 of the present invention. The optical lens 100 includes, in order from the object side to the imaging surface along the optical axis: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1, and a protective glass G2.

[0093] The first lens L1 has negative refractive power, its object-side surface S1 is concave, and its image-side surface S2 is convex;

[0094] The second lens L2 has positive refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave;

[0095] The third lens L3 has negative refractive power, its object-side surface S5 is concave, and its image-side surface S6 is concave;

[0096] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is convex;

[0097] The fifth lens L5 has positive refractive power, its object-side surface S9 is convex, and its image-side surface is convex;

[0098] The sixth lens L6 has negative refractive power, its object-side surface is concave, and its image-side surface S11 is concave;

[0099] The fifth lens L5 and the sixth lens L6 form a cemented lens group with positive refractive power. That is, the cemented surface between the image-side surface of the fifth lens L5 and the object-side surface of the sixth lens L6 is S10.

[0100] The seventh lens L7 has positive refractive power, its object-side surface S12 is convex, and its image-side surface S13 is concave;

[0101] The object-side surface S14 and the image-side surface S15 of the filter G1 are both flat surfaces;

[0102] The object side surface S16 and the image side surface S17 of the protective glass G2 are both flat surfaces;

[0103] The imaging surface S18 is a plane.

[0104] The seventh lens L7 is a glass aspherical lens, and the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are glass spherical lenses.

[0105] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0106] Table 1-1

[0107]

[0108] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0109] Table 1-2

[0110]

[0111]

[0112] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, vertical chromatic aberration curve, and MTF curve of the optical lens 100 are shown as follows: Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 shown.

[0113] Figure 2 The field curvature curves for Example 1 are shown, representing 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 angle (unit: degrees). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.03mm, indicating that the optical lens 100 is able to effectively correct field curvature.

[0114] Figure 3 The F-Tan (Theta) distortion curve for Example 1 shows the distortion of light of different wavelengths at different image heights on the imaging plane. 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 of the optical lens is controlled within a range of -20% to 0, indicating that the optical lens 100 is capable of effectively correcting distortion.

[0115] Figure 4 The axial aberration curve of Example 1 is shown, which shows 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 offset of the axial aberration is controlled within -0.01mm to 0.02mm, indicating that the optical lens 100 is able to correct axial aberration well.

[0116] Figure 5 A graph of vertical chromatic aberration for Example 1 is shown. It plots the chromatic aberration of each wavelength relative to the center wavelength (0.55 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view angle. As can be seen from the graph, the vertical chromatic aberration for both the longest and shortest wavelengths is controlled within a range of -1 μm to 3 μm, demonstrating that the optical lens 100 is capable of excellent chromatic aberration correction.

[0117] Figure 6 The MTF (Modulation Transfer Function) curve for Example 1 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.4 across the entire field of view. Within the range of 0 to 160 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0118] Example 2

[0119] See also Figure 7 , shown is a schematic structural diagram of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0120] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0121] Table 2-1

[0122]

[0123]

[0124] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0125] Table 2-2

[0126] Face number K B C D E F S12 -3.81E+00 1.43E-04 -4.24E-05 7.76E-07 -8.09E-08 1.64E-09 S13 1.27E+00 9.11E-04 -3.42E-05 2.98E-06 -2.26E-07 8.49E-09

[0127] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, vertical chromatic aberration curve, and MTF curve of the optical lens 200 are shown as follows: Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 shown.

[0128] from Figure 8 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.03 mm, indicating that the optical lens 200 can correct the field curvature well.

[0129] from Figure 9 It can be seen from the figure that the distortion of the optical lens is controlled within -20% to 0, which means that the optical lens 200 can correct the distortion well.

[0130] from Figure 10 It can be seen from the figure that the offset of the axial aberration is controlled within -0.01 mm to 0.02 mm, indicating that the optical lens 200 can correct the axial aberration well.

[0131] from Figure 11 It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1μm to 3μm, indicating that the optical lens 200 can correct chromatic aberration very well.

[0132] from Figure 12 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 evenly and smoothly from the center to the edge of the field of view, achieving good imaging quality and detail resolution in both low-frequency and high-frequency conditions.

[0133] Example 3

[0134] See also Figure 13 , shown is a schematic structural diagram of an optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the image-side surface of the fifth lens L5 is concave; the object-side surface of the sixth lens L6 is convex; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0135] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0136] Table 3-1

[0137]

[0138] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0139] Table 3-2

[0140] Face number K B C D E F S12 -2.21E+00 4.57E-04 -3.16E-05 9.32E-07 -1.13E-07 1.41E-09 S13 1.68E+00 1.06E-03 -1.71E-05 3.45E-06 -3.15E-07 1.10E-08

[0141] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, vertical chromatic aberration curve, and MTF curve of the optical lens 300 are shown as follows: Figure 14 、 Figure 15 、 Figure 16 、 Figure 17 、 Figure 18 shown.

[0142] from Figure 14 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.03mm to 0.01mm, indicating that the optical lens 300 can correct the field curvature well.

[0143] from Figure 15 It can be seen from the figure that the distortion of the optical lens is controlled within a range of -20% to 0, indicating that the optical lens 300 can correct the distortion well.

[0144] from Figure 16 It can be seen from the figure that the offset of the axial aberration is controlled within -0.01 mm to 0.02 mm, indicating that the optical lens 300 can correct the axial aberration well.

[0145] from Figure 17 It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1μm to 3μm, indicating that the optical lens 300 can correct chromatic aberration very well.

[0146] 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 evenly and smoothly from the center to the edge of the field of view, achieving good imaging quality and detail resolution in both low-frequency and high-frequency conditions.

[0147] Example 4

[0148] See also Figure 19 , shown is a schematic structural diagram of an optical lens 400 provided in Example 4 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the image-side surface S11 of the sixth lens L6 is a convex surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0149] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0150] Table 4-1

[0151]

[0152]

[0153] The surface parameters of the aspheric lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0154] Table 4-2

[0155] Face number K B C D E F S12 -5.50E+00 4.38E-04 -3.78E-05 1.55E-06 -9.26E-08 1.88E-09 S13 8.62E-01 9.34E-04 -3.15E-05 3.28E-06 -2.00E-07 5.37E-09

[0156] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, vertical chromatic aberration curve, and MTF curve of the optical lens 400 are shown as follows: Figure 20 、 Figure 21 、 Figure 22 、 Figure 23 、 Figure 24 shown.

[0157] from Figure 20 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.03 mm, indicating that the optical lens 400 can correct the field curvature well.

[0158] from Figure 21 It can be seen from the figure that the distortion of the optical lens is controlled within a range of -20% to 0, indicating that the optical lens 400 can correct the distortion well.

[0159] from Figure 22 It can be seen from the figure that the offset of the axial aberration is controlled within -0.01 mm to 0.02 mm, indicating that the optical lens 400 can correct the axial aberration well.

[0160] from Figure 23 It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1μm to 3μm, indicating that the optical lens 400 can correct chromatic aberration very well.

[0161] from Figure 24 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 evenly and smoothly from the center to the edge of the field of view, achieving good imaging quality and detail resolution in both low-frequency and high-frequency conditions.

[0162] Please refer to Table 5, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, real image height IH corresponding to the maximum field of view angle, chief ray incidence angle CRA at the maximum image height, maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0163] Table 5

[0164]

[0165]

[0166] In summary, the optical lens provided by the present invention uses seven lenses with specific optical powers. Through the combination of specific surface shapes and reasonable optical power distribution, it is possible to improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, so that the lens has one or more advantages such as a large target area, a large aperture, and high imaging quality.

[0167] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations 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 any one or more embodiments or examples.

[0168] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An optical lens, comprising seven lenses, characterized in that: It sequentially 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 concave and whose image side is convex; A second lens with a positive optical power, whose object side is convex and whose image side is concave; A third lens with a negative optical power, whose object side is concave and whose image side is concave; A fourth lens with a positive optical power, whose object side is convex and whose image side is convex; A fifth lens with a positive optical power, whose object side is convex; A sixth lens with a negative optical power; A seventh lens with a positive optical power, whose object side is convex and whose image side is concave; Wherein, the focal length f1 of the first lens and the focal length f3 of the third lens satisfy: 1.8 < f1 / f3 < 2.6; The curvature radius R5 of the object side of the third lens and the curvature radius R6 of the image side of the third lens satisfy: -1 < (R5 + R6) / (R5 - R6) < -0.

75.

2. The optical lens according to claim 1, wherein: The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.3 < TTL / f < 4.8; The overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 4 < TTL / IH < 4.

6.

3. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -4.8 < f1 / f < -4.4; The curvature radius R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: -3 < R1 / f < -2.3; The curvature radius R2 of the image side of the first lens and the effective focal length f of the optical lens satisfy: -41 < R2 / f < -39.

4. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 5.3 < f2 / f < 6.1; The curvature radius R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: 2 < R3 / f < 5; The curvature radius R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: 3 < R4 / f < 30.

5. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -2.5 < f3 / f < -1.8; The curvature radius R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: -1.7 < R5 / f < -1.3; The curvature radius R6 of the image side of the third lens and the effective focal length f of the optical lens satisfy: 10 < R6 / f < 42.

6. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.7 < f4 / f < 2.2; The curvature radius R7 of the object side of the fourth lens and the effective focal length f of the optical lens satisfy: 1 < R7 / f < 2; The curvature radius R8 of the image side of the fourth lens and the effective focal length f of the optical lens satisfy: -70 < R8 / f < -3.

7. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.8 < f7 / f < 12.5; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.7 < R13 / f < 1.3; the image-side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.9 < R14 / f < 1.

3.

8. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the combined focal length f123 of the first lens, the second lens, and the third lens satisfy: -2 < f123 / f < -1.6; the effective focal length f of the optical lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: 0.8 < f4567 / f < 1.

9. The optical lens according to claim 1, wherein: The focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -1.4 < f3 / f4 < -0.8; the image-side curvature radius R6 of the third lens and the object-side curvature radius R7 of the fourth lens satisfy: 8 < R6 / R7 < 36.

10. The optical lens according to claim 1, wherein: The object-side curvature radius R1 of the first lens and the image-side curvature radius R2 of the first lens satisfy: -0.9 < (R1 - R2) / (R1 + R2) < -0.85; the central thickness CT1 of the first lens and the central thickness CT2 of the second lens satisfy: 5 < CT1 / CT2 < 7.

Images