Optical lens

Abstract

The invention provides an optical lens, which comprises six lenses with focal power, and sequentially comprises a first lens with positive focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, a fifth lens with positive focal power and a sixth lens with negative focal power from an object side to an imaging surface along an optical axis, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; the fourth lens has positive focal power, and the object side surface of the fourth lens is a convex surface; the fifth lens has negative focal power; the sixth lens has positive focal power; wherein the focal length f6 of the sixth lens and the effective focal length f of the optical lens meet the following conditions: 1lt; f6 / flt; 5; the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens meet the following conditions: 0.65 lt; r4 / flt; 2.2. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal power distribution, the lens has one or more advantages of long focus, large aperture, high imaging quality and the like.

Description

Technical Field

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

[0002] With the continuous improvement of people's requirements for driving experience, in-vehicle application optical lenses are increasingly used in intelligent driving, and the status of in-vehicle optical lenses in the automotive-related industry is continuously rising.

[0003] Advanced Driver Assistance Systems (ADAS) play an important role in intelligent driving. It collects environmental information through various lenses and sensors to ensure the driving safety of the driver. In addition to requiring the optical lens to have a thin, light, short and small shape and high pixel and high resolution characteristics, the existing ADAS system lenses also require the optical lens to be able to clearly image under low illuminance conditions. Therefore, it is necessary to develop an optical lens with good imaging effect. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide an optical lens with the advantage of excellent imaging quality.

[0005] The technical solution adopted by the present invention is as follows:

[0006] An optical lens, the number of lenses with optical power is six, and sequentially includes from the object side to the imaging surface along the optical axis:

[0007] A first lens with positive optical power, the object side surface of which is convex;

[0008] A second lens with negative optical power, the object side surface of which is concave, and the image side surface of which is concave;

[0009] A third lens with positive optical power, the object side surface of which is convex, and the image side surface of which is convex;

[0010] A fourth lens with positive optical power, the object side surface of which is convex;

[0011] A fifth lens with negative optical power;

[0012] A sixth lens with positive optical power;

[0013] Wherein, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 1 < f6 / f < 5; the image side curvature radius R4 of the second lens and the effective focal length f of the optical lens satisfy: 0.65 < R4 / f < 2.2.

[0014] Further preferably, the combined focal length f12 of the first lens and the second lens and the combined focal length f36 of the third lens, the fourth lens, the fifth lens and the sixth lens satisfy: -4.2 <f12 / f36<-1.2。

[0015] Further preferably, the object-side aperture d1 of the first lens and the image-side aperture d12 of the sixth lens satisfy: 1.2 <d1 / d12<2.9。

[0016] Further preferably, the object-side half-aperture height SAG3 of the sixth lens, the image-side half-aperture height SAG4 of the sixth lens, and the center thickness CT2 of the sixth lens satisfy: 0.2 < (SAG4 - SAG3) / CT2 < 2.5.

[0017] Further preferably, the total optical length (TTL) of the optical lens, the true image height (IH) corresponding to the maximum field of view (FOV) of the optical lens, and the maximum field of view (FOV) of the optical lens satisfy: 0.1 / ° <TTL / IH / FOV<0.3 / °。

[0018] Further preferably, the true image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 50° <f×FOV / IH<60°。

[0019] Further preferably, the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -0.6 <f5 / f6<-0.1。

[0020] Further preferably, the object-side radius of curvature R3 of the second lens and the image-side radius of curvature R4 of the second lens satisfy: -2.9 <R3 / R4<-0.55。

[0021] Further preferably, the object-side light-transmitting half-aperture height SAG11 of the sixth lens, the image-side light-transmitting half-aperture height SAG12 of the sixth lens, and the center thickness CT6 of the sixth lens satisfy: -0.1<(SAG12-SAG11) / CT6<0.1.

[0022] Further preferably, the object-side radius of curvature R11 of the sixth lens and the image-side radius of curvature R12 of the sixth lens satisfy: -0.4<(R11-R12) / (R11+R12)<1.1.

[0023] The optical lens provided by this invention uses six 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 telephoto, large aperture, and high imaging quality. Attached Figure Description

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0025] Figure 1 This is a schematic diagram of the optical lens in Embodiment 1 of the present invention.

[0026] Figure 2 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 3 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 4 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 5 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 6 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 7 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0032] Figure 8 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 9 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 10 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0035] Figure 11 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0036] Figure 12 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0037] Figure 13 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 14 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0039] Figure 15 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.

[0040] Figure 16 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0041] Figure 17 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0042] Figure 18 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0043] Figure 19 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0044] Figure 20 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0045] Figure 21 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 4 of the present invention.

[0046] Figure 22 This is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0047] Figure 23 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0048] Figure 24 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0049] Figure 25 This is a schematic diagram of the optical lens structure in Embodiment 5 of the present invention.

[0050] Figure 26 This is a field curvature curve diagram of the optical lens in Embodiment 5 of the present invention.

[0051] Figure 27 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 5 of the present invention.

[0052] Figure 28 This is an axial aberration curve of the optical lens in Embodiment 5 of the present invention.

[0053] Figure 29 This is a chromatic aberration curve of the optical lens in Embodiment 5 of the present invention.

[0054] Figure 30 This is the MTF curve of the optical lens in Embodiment 5 of the present invention.

[0055] Figure 31 This is a schematic diagram of the optical lens in Embodiment 6 of the present invention.

[0056] Figure 32 This is a field curvature curve diagram of the optical lens in Embodiment 6 of the present invention.

[0057] Figure 33 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 6 of the present invention.

[0058] Figure 34 This is an axial aberration curve of the optical lens in Embodiment 6 of the present invention.

[0059] Figure 35 This is a chromatic aberration curve of the optical lens in Embodiment 6 of the present invention.

[0060] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0061] 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.

[0062] 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.

[0063] 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.

[0064] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] The optical lens provided in this embodiment of the invention has six lenses with optical power, which are arranged sequentially from the object side to the imaging plane along the optical axis as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens.

[0069] In some embodiments, the first lens may have positive optical power, with its object-side surface being convex and its image-side surface being either concave or convex. The second lens may have negative optical power, with both its object-side and image-side surfaces being concave. The third lens may have positive optical power, with both its object-side and image-side surfaces being convex. The fourth lens may have positive optical power, with both its object-side and image-side surfaces being convex. The fifth lens may have negative optical power, with both its object-side and image-side surfaces being either concave or convex. The sixth lens may have positive optical power, with both its object-side and image-side surfaces being either concave or convex.

[0070] In some embodiments, the optical lens may further include an aperture, which may be located between the second lens and the third lens. It can be understood that the aperture is used to limit the amount of incident light to change the brightness of the image. When the aperture is located between the second lens and the third lens, it is convenient for correcting the aperture aberration.

[0071] In some embodiments, the optical lens may further include a filter, which is disposed between the sixth lens and the imaging surface. The filter is used to filter out interfering light and prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0072] In some embodiments, the fourth lens and the fifth lens may be glued together to form a cemented 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.

[0073] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 1 < f6 / f < 5. Satisfying the above range is beneficial to suppressing the angle of the marginal field of view incident on the imaging surface, effectively transmitting more light beams to the imaging surface, and at the same time being able to balance the field curvature and spherical aberration of the optical lens, improving the imaging quality of the optical lens.

[0074] In some embodiments, the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 0.65 < R4 / f < 2.2. Reasonably controlling the curvature radius of the image side surface of the second lens is beneficial to controlling the shape of the second lens, optimizing the aberration balance of the lens group, and improving the imaging quality.

[0075] In some embodiments, the combined focal length f12 of the first lens and the second lens and the combined focal length f36 of the third lens, the fourth lens, the fifth lens, and the sixth lens satisfy: -4.2 < f12 / f36 < -1.2. Satisfying the above range can reasonably distribute the proportion of the optical power of the lens groups before and after the aperture, increase the relative illumination of the lens, and improve the imaging quality of the lens.

[0076] In some embodiments, the clear aperture radius d1 of the object side surface of the first lens and the clear aperture radius d12 of the image side surface of the sixth lens satisfy: 1.2 < d1 / d12 < 2.9. By reasonably setting the ratio of the apertures of the first and last lenses, the lens can have a smaller head size while having a larger imaging surface, and can better meet the balance of miniaturization and high pixel.

[0077] In some embodiments, the sagittal height SAG3 of the clear aperture semi-diameter on the object side of the sixth lens, the sagittal height SAG4 of the clear aperture semi-diameter on the image side of the sixth lens, and the central thickness CT2 of the sixth lens satisfy: 0.2 < (SAG4 - SAG3) / CT2 < 2.5. Satisfying the above conditions can limit the degree of central depression of the second lens and reduce the difficulty of aberration correction for the marginal field of view.

[0078] In some embodiments, the total optical length TTL of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.1 / ° < TTL / IH / FOV < 0.3 / °. Satisfying the above range can achieve a balance among large image height, long focal length, and miniaturization, and improve the imaging quality of the optical lens.

[0079] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 50° < f×FOV / IH < 60°. Satisfying the above conditional formula is conducive to achieving the balance between the field angle of the optical lens and large target surface imaging by reasonably restricting the relationship among the focal length, field angle, and image height of the optical lens, and better meeting the usage requirements of high image quality shooting of the optical lens.

[0080] In some embodiments, the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -0.6 < f5 / f6 < -0.1. Satisfying the above range can converge the incident angle of marginal rays by reasonably setting the focal length relationship between the fifth lens and the sixth lens, improve the illumination uniformity and clarity of the picture edge, and simultaneously finely correct aberrations such as distortion, so that the lens picture can obtain a high-quality, dark corner-free, and undistorted clear image.

[0081] In some embodiments, 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: -2.9 < R3 / R4 < -0.55. Satisfying the above conditions can make the second lens have an appropriate positive optical power, smoothly transition the light rays, and reduce the difficulty of chromatic aberration correction for the optical lens.

[0082] In some embodiments, the sagittal height SAG11 of the clear aperture semi-diameter on the object side of the sixth lens, the sagittal height SAG12 of the clear aperture semi-diameter on the image side of the sixth lens, and the central thickness CT6 of the sixth lens satisfy: -0.1 < (SAG12 - SAG11) / CT6 < 0.1. Satisfying the above conditions is conducive to correcting the coma of the off-axis field of view and improving the imaging quality of the off-axis field of view of the optical lens by controlling the relationship between the height difference of the sagittal heights of the image side and the object side of the sixth lens and the central thickness of the sixth lens.

[0083] In some embodiments, 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: -0.4 < (R11 - R12) / (R11 + R12) < 1.1. Meeting the above range is conducive to suppressing the angle of incidence of the marginal field of view on the imaging surface, effectively transmitting more light beams to the imaging surface, and at the same time being able to balance the field curvature and spherical aberration of the optical lens, improving the imaging quality of the optical lens.

[0084] In some embodiments, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: 1.4 < f12 / f < 4.5. Meeting the above requirements, by reasonably distributing the optical power of the first lens to the second lens, the deflection angle of the light rays at the front end of the lens is reduced, and the generation of various off-axis aberrations is reduced.

[0085] In some embodiments, the combined focal length f36 of the third lens, the fourth lens, the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: -2.2 < f36 / f < -0.72. Meeting the above requirements, by reasonably distributing the optical power of the third lens to the sixth lens, the focal length of the optical lens is balanced, the correction ability of various aberrations at the rear end of the lens is improved, and the imaging quality of the optical lens is improved.

[0086] In some embodiments, the combined focal length f45 of the fourth lens and the fifth lens and the effective focal length f of the optical lens satisfy: 0.37 < f45 / f < 0.7. Meeting the above conditions helps more light rays enter the cemented lens smoothly and helps improve the illuminance.

[0087] In some embodiments, the object side light-passing semi-aperture sag SAG7, the image side light-passing semi-aperture sag SAG8 of the fourth lens and the central thickness CT of the fourth lens satisfy: -0.8 < (SAG8 - SAG7) / CT4 < -0.4. Meeting the above conditions can control the surface shape of the object side surface of the fourth lens, which is beneficial to the manufacturing and forming of the fourth lens, reducing the defective rate. In addition, it can also prevent the surface shape from being too curved and complex, making the system field curvature tend to be balanced.

[0088] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.8 < TTL / f < 3.5. Meeting the above range can effectively limit the length of the lens, which is beneficial to the miniaturization of the optical lens.

[0089] 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: 3 < TTL / IH < 7. It can better achieve the miniaturization of the lens, and at the same time ensure that under the same overall length of the lens, it has a larger image surface and can match a larger-sized imaging chip to achieve high-definition imaging.

[0090] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.98 < (IH / 2) / (f×tan(FOV / 2)) < 1.07. Meeting the above requirements indicates that the optical distortion of the optical lens is well controlled, improving the resolution of the optical lens.

[0091] In some embodiments, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 13° < FOV / Fno < 27°. Meeting the above conditions is beneficial to increasing the light input of the lens, enabling the lens to achieve high-definition imaging even in a dim environment.

[0092] 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: 0.55 < IH / EPD < 1.1. Meeting the above range enables the optical lens to meet the large image plane while ensuring sufficient image plane brightness in the edge field of view, preventing the occurrence of vignetting, thereby improving the imaging quality. [[ID=​​​​​​​​​​​​In some embodiments, the back focal length BFL of the optical lens and the total optical length TTL of the optical lens satisfy: 0.05 < BFL / TTL < 0.13. Reasonably configuring the ratio of the back focal length of the optical lens to the total optical length of the optical lens is beneficial to achieving a short back focal length of the optical lens, and is beneficial to miniaturizing the optical lens while ensuring sufficient space for the installation and focusing of optical elements.

[0098] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the aperture value Fno of the optical lens satisfy: 2.7 mm < IH / Fno < 6.2 mm. Satisfying the above conditions can ensure a large aperture of the optical lens while maintaining a large image plane of the optical lens, achieving a balance between a large image plane and a large aperture.

[0099] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -1.3 < f2 / f < -0.6. Satisfying the above conditions, the second lens uses a negative focal lens with a weak refractive power, which can avoid introducing too strong light deflection, thereby better controlling other aberrations (such as spherical aberration and coma).

[0100] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.5 < f4 / f < 0.8; the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -~0.7 < f5 / f < -0.4. The fourth lens and the fifth lens are glued together to form a doublet lens. The fourth lens and the fifth lens can have opposite optical powers, so that various aberrations of the optical lens can be fully corrected, the resolution can be improved, and high resolution can be achieved. At the same time, the use of the glued part is beneficial to reducing the tolerance sensitivity of the lens to tilt / eccentricity during the assembly process, improving the resolution stability, and further improving the system performance.

[0101] In some embodiments, the focal length f4 of the fourth lens and the focal length f5 of the fifth lens satisfy: -1.5 < f4 / f5 < -0.8. Satisfying the above conditions, by reasonably setting the focal lengths of the fourth and fifth lenses, better convergence of light can be achieved, the distance for light to enter the next lens can be shortened, and it is beneficial to miniaturize the optical lens.

[0102] In some embodiments, the central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy: 0.2 < CT2 / CT3 < 1.3. Satisfying the above conditions can reduce the sensitivity of the system performance, while ensuring the lens processing performance and assembly stability, and improving the assembly yield.

[0103] In some embodiments, the central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 0.3 < CT3 / CT4 < 1.1. Satisfying the above relationship, the two match each other, which helps to eliminate axial chromatic aberration.

[0104] In some embodiments, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: -0.8 < R1 / R2 < 0.95. By satisfying the above conditions, the light transmission amount of the optical lens can be effectively increased, and the field of view range of the optical lens can be effectively expanded.

[0105] In some embodiments, the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: -8 < (R9 - R10) / (R9 + R10) < 0.8. By making the optical system satisfy the above relational expression, it is beneficial to rationally configure the ratio of the radius of curvature of the object side surface and the image side surface of the fifth lens, control the shape of the fifth lens, comprehensively balance the spherical aberration, chromatic aberration and field curvature of the optical system, and reduce the risk of generating ghost images, improve the resolution ability of the optical system. At the same time, it is also beneficial to reduce the processing difficulty of the fifth lens.

[0106] In some embodiments, the optical lens satisfies the following conditional expressions: 9mm < f < 16mm; 6mm < EPD < 10mm; 30mm < TTL < 33mm; 1.3 < Fno < 1.8; 11° < CRA < 29°; 1.8mm < BFL < 4mm; 20° < FOV < 35°; 4mm < IH < 10mm. 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 principal ray incident angle at the maximum image height of the optical lens, BFL represents the back focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, and IH represents the true image height corresponding to the maximum field of view angle of the optical lens. By satisfying 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.

[0107] In some embodiments, the lens material in 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. 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.

[0108] In some embodiments, the first, second, third, fourth, fifth, and sixth 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 sixth lens of this invention is an aspherical lens; the first, second, third, fourth, and fifth lenses are spherical lenses.

[0109] 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:

[0110]

[0111] 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, and F are the fourth, sixth, eighth, tenth, and twelfth order surface coefficients, respectively.

[0112] 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.

[0113] Example 1

[0114] Please see Figure 1 The figure shown is a schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, in sequence along the optical axis from the object side to the imaging plane: a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a filter G1.

[0115] Among them, the first lens L1 has positive optical power, its object side S1 is convex, and its image side S2 is concave.

[0116] The second lens L2 has negative optical power, its object side S3 is concave, and its image side S4 is concave.

[0117] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is convex.

[0118] The fourth lens L4 has positive optical power, its object side S7 is convex, and its image side is convex.

[0119] The fifth lens L5 has negative optical power, its object side is concave, and its image side S9 is concave.

[0120] The fourth lens L4 and the fifth lens L5 form a cemented lens group with positive optical power, that is, the cemented surface of the image side of the fourth lens L4 and the object side of the fifth lens L5 is S8.

[0121] The sixth lens L6 has positive optical power, its object side S10 is convex, and its image side S11 is concave.

[0122] The object-side surface S12 and the image-side surface S13 of the filter G1 are both planar.

[0123] The imaging plane S14 is a plane.

[0124] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are glass spherical lenses; the sixth lens L6 is a glass aspherical lens.

[0125] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0126] Table 1-1

[0127]

[0128]

[0129] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0130] Table 1-2

[0131] Face number K B C D E F S10 5.22E-01 -5.75E-04 -2.03E-05 6.21E-07 -6.12E-08 1.16E-09 S11 8.91E+00 -3.09E-04 -2.09E-05 5.22E-07 -2.50E-08 6.27E-10

[0132] In this embodiment, the field curvature curve, F-Tan (Theta) 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.

[0133] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light 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 ±0.02 mm, indicating that the optical lens can effectively correct the field curvature.

[0134] Figure 3 The F-Tan (Theta) distortion curves for Example 1 are shown, representing the F-Tan (Theta) 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 of view (unit: °). As can be seen from the figure, the F-Tan (Theta) distortion of the optical lens is controlled within -2% to 0, indicating that the optical lens can effectively correct distortion.

[0135] Figure 4 The diagram shows the axial aberration curves for Example 1, representing the aberrations of each wavelength along 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. The diagram shows that the axial aberration offset is controlled within ±0.02 mm, indicating that the optical lens can effectively correct axial aberrations.

[0136] 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 (0.55 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 ±1 μm, indicating that the optical lens can effectively correct chromatic aberration.

[0137] 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 0–120 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.

[0138] Example 2

[0139] Please see Figure 7 The figure shows 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 image side surface S9 of the fifth lens L5 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0140] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0141] Table 2-1

[0142]

[0143] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0144] Table 2-2

[0145] Face number K B C D E F S10 1.37E-01 -3.10E-04 -9.11E-06 4.33E-07 -4.12E-08 8.09E-10 S11 1.82E+00 -1.60E-04 -2.76E-05 -8.41E-06 7.81E-07 -7.51E-08

[0146] In this embodiment, the field curvature curve, F-Tan (Theta) 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.

[0147] from Figure 8 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.02mm, indicating that the optical lens can effectively correct the field curvature.

[0148] from Figure 9 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within ±2%, indicating that the optical lens can correct distortion well.

[0149] from Figure 10 As can be seen, the axial aberration offset is controlled within ±0.01mm, indicating that the optical lens can effectively correct axial aberration.

[0150] from Figure 11 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1μm, indicating that the optical lens can effectively correct chromatic aberration.

[0151] from Figure 12 As can be seen, the MTF value of this embodiment is above 0.65 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0152] Example 3

[0153] Please see Figure 13 The figure shows 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 image side surface S2 of the first lens L1 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0154] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0155] Table 3-1

[0156]

[0157]

[0158] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0159] Table 3-2

[0160] Face number K B C D E F S10 2.06E-01 -1.07E-03 -7.32E-05 9.12E-06 -1.13E-06 4.68E-08 S11 4.35E+00 -5.76E-04 -8.16E-05 -3.64E-05 6.40E-06 -7.32E-07

[0161] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 300 are respectively as follows: Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 As shown.

[0162] from Figure 14 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.02mm, indicating that the optical lens can effectively correct the field curvature.

[0163] from Figure 15 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within ±2%, indicating that the optical lens can correct distortion well.

[0164] from Figure 16 As can be seen, the axial aberration offset is controlled within ±0.01mm, indicating that the optical lens can effectively correct axial aberration.

[0165] from Figure 17 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1μm, indicating that the optical lens can effectively correct chromatic aberration.

[0166] from Figure 18 As can be seen, the MTF value of this embodiment is above 0.5 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0167] Example 4

[0168] Please see Figure 19The diagram shows a schematic of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the image-side surface S2 of the first lens L1 is convex; the image-side surface of the fourth lens L4 is concave; the object-side surface of the fifth lens L5 is convex; the object-side surface S10 of the sixth lens L6 is concave; the image-side surface S11 of the sixth lens L6 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0169] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0170] Table 4-1

[0171]

[0172]

[0173] The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0174] Table 4-2

[0175] Face number K B C D E F S10 -7.14E+27 -6.83E-03 -3.43E-04 -2.15E-04 3.97E-05 -6.06E-06 S11 -9.12E+01 -7.78E-03 7.05E-04 -1.40E-04 1.25E-05 -4.05E-07

[0176] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 400 are respectively as follows: Figure 20 , Figure 21 , Figure 22 , Figure 23 , Figure 24 As shown.

[0177] from Figure 20 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.03mm, indicating that the optical lens can effectively correct the field curvature.

[0178] from Figure 21 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within 0-8%, indicating that the optical lens can correct distortion well.

[0179] from Figure 22 As can be seen, the axial aberration offset is controlled within -0.01mm to 0.03mm, indicating that the optical lens can effectively correct axial aberration.

[0180] from Figure 23 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1.5μm, indicating that the optical lens can effectively correct chromatic aberration.

[0181] from Figure 24As can be seen, the MTF value of this embodiment is above 0.38 throughout the entire field of view. In the range of 0 to 120 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.

[0182] Example 5

[0183] Please see Figure 25 The diagram shows a schematic of the structure of the optical lens 500 provided in Embodiment 5 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the image-side surface S2 of the first lens L1 is convex; the image-side surface of the fourth lens L4 is concave; the object-side surface of the fifth lens L5 is convex; the object-side surface S10 of the sixth lens L6 is concave; the image-side surface S11 of the sixth lens L6 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0184] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0185] Table 5-1

[0186]

[0187] The surface profile parameters of the aspherical lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0188] Table 5-2

[0189] Face number K B C D E F S10 -1.06E+33 -7.83E-03 -4.18E-04 -2.38E-04 4.14E-05 -6.37E-06 S11 -2.00E+02 -7.43E-03 5.40E-04 -1.50E-04 1.84E-05 -8.43E-07

[0190] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 500 are respectively as follows: Figure 26 , Figure 27 , Figure 28 , Figure 29 , Figure 30 As shown.

[0191] from Figure 26 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.04mm to 0.02mm, indicating that the optical lens can effectively correct the field curvature.

[0192] from Figure 27 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within 0-6%, indicating that the optical lens can correct distortion well.

[0193] from Figure 28As can be seen, the axial aberration offset is controlled within -0.01mm to 0.02mm, indicating that the optical lens can effectively correct axial aberration.

[0194] from Figure 29 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1μm, indicating that the optical lens can effectively correct chromatic aberration.

[0195] from Figure 30 As can be seen, the MTF value of this embodiment is above 0.5 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0196] Example 6

[0197] Please see Figure 31 The figure shown is a schematic diagram of the structure of the optical lens 600 provided in Embodiment 6 of the present invention. The main difference between this embodiment and Embodiment 1 is that the fourth lens L4 and the fifth lens L5 do not form a cemented lens group; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0198] The relevant parameters of each lens in the optical lens 600 in Example 6 are shown in Table 6-1.

[0199] Table 6-1

[0200]

[0201]

[0202] The surface profile parameters of the aspherical lens of the optical lens 600 in Example 6 are shown in Table 6-2.

[0203] Table 6-2 In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 600 are respectively as follows: Figure 32 , Figure 33 , Figure 34 , Figure 35 As shown.

[0206] from Figure 32 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.06mm to 0.1mm, indicating that the optical lens can effectively correct the field curvature.

[0207] from Figure 33 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within ±2%, indicating that the optical lens can correct distortion well.

[0208] from Figure 34 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.01mm, indicating that the optical lens can effectively correct axial aberration.

[0209] from Figure 35 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1μm, indicating that the optical lens can effectively correct chromatic aberration.

[0210] Please refer to Table 7 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.

[0211] Table 7

[0212]

[0213]

[0214] In summary, the optical lens provided by the present invention employs six 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 telephoto, large aperture, and high imaging quality.

[0215] 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.

[0216] 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 six lenses having optical power, characterized in that, It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with positive optical power, whose object side is convex; A second lens with negative optical power, whose object side is concave and whose image side is concave; A third lens with positive optical power, whose object side is convex and whose image side is convex; A fourth lens with positive optical power, whose object side is convex; A fifth lens with negative optical power; A sixth lens with positive optical power; Wherein, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 1 < f6 / f < 5; the radius of curvature R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: 0.65 < R4 / f < 2.

2.

2. The optical lens according to claim 1, characterized in that, The combined focal length f12 of the first lens and the second lens and the combined focal length f36 of the third lens, the fourth lens, the fifth lens and the sixth lens satisfy: -4.2 < f12 / f36 < -1.

2.

3. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter d1 of the object side of the first lens and the clear aperture semi-diameter d12 of the image side of the sixth lens satisfy: 1.2 < d1 / d12 < 2.

9.

4. The optical lens according to claim 1, characterized in that, The sagittal height SAG3 of the clear aperture of the object side of the sixth lens, the sagittal height SAG4 of the clear aperture of the image side of the sixth lens and the central thickness CT2 of the sixth lens satisfy: 0.2 < (SAG4 - SAG&3) / CT2 < 2.

5.

5. The optical lens according to claim 1, characterized in that, The overall optical length TTL of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.1 / ° < TTL / IH / FOV < 0.3 / °.

6. The optical lens according to claim 1, characterized in that, The true image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens and the maximum field angle FOV of the optical lens satisfy: 50° < f×FOV / IH < 60°.

7. The optical lens according to claim 1, characterized in that, The focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -0.6 < f5 / f6 < -0.

1.

8. 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 radius of curvature R4 of the image side of the second lens satisfy: -2.9 < R3 / R4 < -0.

55.

9. The optical lens according to claim 1, characterized in that, The sagittal height SAG11 of the clear aperture of the object side of the sixth lens, the sagittal height SAG12 of the clear aperture of the image side of the sixth lens and the central thickness CT6 of the sixth lens satisfy: -0.1 < (SAG12 - SAG11) / CT6 < 0.

1.

10. The optical lens according to claim 1, characterized in that, The radius of curvature R11 of the object side of the sixth lens and the radius of curvature R12 of the image side of the sixth lens satisfy: -0.4 < (R11 - R12) / (R11 + R12) < 1.1.

Images