Optical lens

Abstract

The invention provides an optical lens, which comprises six lenses from an object side to an imaging surface along an optical axis: a first lens with positive focal power; the second lens has positive focal power; the third lens has positive focal power; the fourth lens has negative focal power; the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a concave surface; the sixth lens has negative focal power, and the object side surface of the sixth lens is a concave surface; wherein the curvature radius R10 of the image side surface of the fifth lens and the curvature radius R11 of the object side surface of the sixth lens meet the following conditions: 0 lt; (R10 + R11) / (R10-R11) lt; 1. According to the optical lens provided by the invention, the six lenses with specific focal power are adopted, and through specific surface shape matching and reasonable focal power distribution, 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 long focus, large target surface, high imaging quality and the like.

Description

Technical Field

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

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

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

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

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

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

[0007] A first lens with positive optical power;

[0008] A second lens with positive optical power;

[0009] A third lens with positive optical power;

[0010] A fourth lens with negative optical power;

[0011] The fifth lens with positive optical power has a convex object side and a concave image side.

[0012] The sixth lens has negative optical power and its object side is concave.

[0013] The image-side curvature radius R10 of the fifth lens and the object-side curvature radius R11 of the sixth lens satisfy: 0 < (R10 + R11) / (R10 - R11) < 1.

[0014] Further preferably, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 12° < FOV / Fno < 17.5°; the total optical length TTL of the optical lens, the maximum field of view FOV of the optical lens, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 85 < 180° × TTL / IH / FOV < 119.

[0015] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: f5 / f > 0.6.

[0016] Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.7 < f6 / f < -0.4.

[0017] Further preferably, the effective focal length f of the optical lens and the object-side curvature radius R9 of the fifth lens satisfy: 0.4 < R9 / f < 1.

[0018] Further preferably, the effective focal length f of the optical lens and the image-side curvature radius R10 of the fifth lens satisfy: 0.5 < R10 / f < 7.

[0019] Further preferably, the effective focal length f of the optical lens and the object-side curvature radius R11 of the sixth lens satisfy: -2.7 < R11 / f < -0.3.

[0020] Further preferably, the object-side curvature radius R3 and the image-side curvature radius R4 of the second lens satisfy: 0.2 < R3 / R4 < 1.1; the object-side curvature radius R7 and the image-side curvature radius R8 of the fourth lens satisfy: 0.4 < R7 / R8 < 8.3.

[0021] Further preferably, the object-side curvature radius R9 and the image-side curvature radius R10 of the fifth lens satisfy: |(R9 - R10) / (R9 + R10)| < 0.9.

[0022] Further preferably, the image-side clear aperture sag Sag10 and the image-side clear aperture d10 of the fifth lens satisfy: 0 < Sag10 / d10 < 0.3; the object-side clear aperture sag Sag11 and the object-side clear aperture d11 of the sixth lens satisfy: -0.4 < Sag11 / d11 < 0.

[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 long focal length, large target surface, 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 structure in Embodiment 1 of the present invention.

[0026] Figure 2 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 3 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 4 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0029] Figure 5 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.

[0030] Figure 6 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 7 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0032] Figure 8 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.

[0033] Figure 9 This is the MTF curve of the optical lens in Embodiment 3 of the present invention.

[0034] Figure 10 This is a schematic diagram of the optical lens in Embodiment 4 of the present invention.

[0035] Figure 11 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 4 of the present invention.

[0036] Figure 12 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0037] Figure 13This is a schematic diagram of the optical lens structure in Embodiment 5 of the present invention.

[0038] Figure 14 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 5 of the present invention.

[0039] Figure 15 This is the MTF curve of the optical lens in Embodiment 5 of the present invention.

[0040] Figure 16 This is a schematic diagram of the optical lens in Embodiment 6 of the present invention.

[0041] Figure 17 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 6 of the present invention.

[0042] Figure 18 This is the MTF curve of the optical lens in Embodiment 6 of the present invention.

[0043] Figure 19 This is a schematic diagram of the optical lens in Embodiment 7 of the present invention.

[0044] Figure 20 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 7 of the present invention.

[0045] Figure 21 This is the MTF curve of the optical lens in Embodiment 7 of the present invention.

[0046] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] The optical lens provided in this embodiment of the invention includes six lenses, 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.

[0055] In some embodiments, the first lens may have a positive optical power. Its object side may be concave or convex, and its image side may be concave or convex. The second lens may have a positive optical power. Its object side may be concave or convex, and its image side may be concave or convex. The third lens may have a positive optical power. Its object side may be concave or convex, and its image side may be concave or convex. The fourth lens may have a negative optical power. Its object side may be concave or convex, and its image side may be concave or convex. The fifth lens may have a positive optical power. Its object side is convex, and its image side is concave. The sixth lens may have a negative optical power. Its object side is concave, and its image side may be concave or convex.

[0056] 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 imaging. When the aperture is located between the second lens and the third lens, it is convenient for correcting the aperture aberration.

[0057] In some embodiments, the optical lens may further include a filter, which may be 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.

[0058] In some embodiments, the third lens and the fourth 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.

[0059] In some embodiments, the radius of curvature R10 of the image side of the fifth lens and the radius of curvature R11 of the object side of the sixth lens satisfy: 0 < (R10 + R11) / (R10 - R11) < 1. Meeting the above range is beneficial to slowing down the change degree of the refraction angle of the incident light and avoiding excessive aberration caused by too strong refraction change. More specifically, 0.11 < (R10 + R11) / (R10 - R11) < 0.8.

[0060] In some embodiments, the maximum field of view FOV of the optical lens and the f-number Fno of the optical lens satisfy: 12° < FOV / Fno < 17.5°. Meeting the above range defines that the optical lens has a suitable field of view and f-number, can collect light at a large angle and obtain good imaging quality. More specifically, 13.3° < FOV / Fno < 16.9°.

[0061] In some embodiments, the total optical length TTL of the optical lens, the maximum field angle FOV of the optical lens, and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 85 < 180° × TTL / IH / FOV < 119. Meeting the above range is conducive to balancing the relationship among the total length, image height, and field angle of the optical lens. More specifically, 85.43 < 180° × TTL / IH / FOV < 118.12.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: f5 / f > 0.6. Meeting the above range can balance lens aberration and improve imaging quality. More specifically, f5 / f > 0.65.

[0063] 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 < -0.4. Meeting the above range defines that the sixth lens has a negative optical power, which is conducive to increasing the imaging area of the optical lens. At the same time, it can optimize the chromatic aberration of the optical lens and improve the imaging quality of the optical lens. More specifically, -1.7 < f6 / f < -0.48.

[0064] In some embodiments, the radius of curvature R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.4 < R9 / f < 1; the radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.5 < R10 / f < 7. Meeting the above range can limit the surface shapes of the object side and image side of the fifth lens, have the characteristic of correcting field curvature, and is conducive to the correction of the aberration of the entire optical lens. More specifically, 0.54 < R9 / f < 0.86; 0.6 < R10 / f < 6.37.

[0065] In some embodiments, the radius of curvature R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -2.7 < R11 / f < -0.3. Meeting the above range controls the object side surface of the sixth lens to be concave, which is conducive to increasing the imaging area and field angle of the optical lens, balancing the aberration of the optical lens, and improving the imaging quality of the optical lens. More specifically, -2.46 < R11 / f < -0.37.

[0066] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: 0.2 < R3 / R4 < 1.1; meeting the above range can effectively slow down the degree of light deflection when entering the second lens, which is conducive to maintaining the miniaturization of the lens head and increasing the light flux entering the lens at the same time. More specifically, 0.32 < R3 / R4 < 0.99.

[0067] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 0.4 < R7 / R8 < 8.3. By satisfying the above range and reasonably setting the surface shape of the fourth lens, the trend of light can be reasonably controlled, avoiding the problem of excessive lens sensitivity caused by excessive light deflection. More specifically, 0.52 < R7 / R8 < 7.56.

[0068] 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: |(R9 - R10) / (R9 + R10)| < 0.9. By satisfying the above range, the surface shapes of the object side and image side of the fifth lens can be restricted, having the characteristic of correcting field curvature, which is beneficial to the correction of the aberration of the entire optical lens. More specifically, -0.8 < (R9 - R10) / (R9 + R10) < 0.06.

[0069] In some embodiments, the sagittal height Sag10 of the clear aperture of the image side surface of the fifth lens and the clear aperture diameter d10 of the image side surface of the fifth lens satisfy: 0 < Sag10 / d10 < 0.3; the sagittal height Sag11 of the clear aperture of the object side surface of the sixth lens and the clear aperture diameter d11 of the object side surface of the sixth lens satisfy: -0.4 < Sag11 / d11 < 0. By satisfying the above range, it helps to control the trend of light in the marginal field of view and highlight the detailed information of the central field of view of the optical lens. More specifically, 0.01 < Sag10 / d10 < 0.21; -0.3 < Sag11 / d11 < -0.06.

[0070] 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 < 2.8. By satisfying the above range, it is beneficial to limit the overall length of the lens while better realizing the long focal length performance of the system. More specifically, 2 < TTL / f < 2.59.

[0071] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3.4 < TTL / IH < 5. By satisfying the above range, a better balance between the overall length of the lens and the image plane is achieved. More specifically, 3.7 < TTL / IH < 4.6.

[0072] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 0.9 < IH / EPD < 1.3. By satisfying the above range, the width of the light beam entering the optical lens can be increased, improving the brightness at the image plane of the optical lens and avoiding vignetting. More specifically, 1.02 < IH / EPD < 1.16.

[0073] 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: 0.4 < IH / f < 0.7. Meeting 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 characteristics of a long focal length and a large image plane, improving the imaging quality. More specifically, 0.48 < IH / f < 0.58.

[0074] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.25 < BFL / f < 0.5. Meeting the above range and defining that the optical lens has an appropriate back focus facilitates the reasonable arrangement of the positions of each lens and reduces the processing and assembly difficulty. More specifically, 0.3 < BFL / f < 0.4.

[0075] 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 sixth lens along the optical axis satisfy: 0.6 < ∑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 the characteristics of high pixels and improve the imaging quality of the optical lens. More specifically, 0.61 < ∑CT / TTL < 0.75.

[0076] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: f1 / f > 1.1. Meeting the above range and setting the first lens to have a positive refractive power can converge the incident light rays and allow more light rays to enter the system, which is beneficial to increasing the light input of the lens and enabling the lens to achieve high-definition imaging in a darker environment. More specifically, f1 / f > 1.22.

[0077] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: f2 / f > 1.2. Meeting the above range and defining that the second lens has a positive optical power is beneficial to further converging the light rays, making the light ray trend smoother, optimizing the aberration, and improving the resolution. More specifically, f2 / f > 1.37.

[0078] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.5 < f3 / f < 1. Meeting the above range and reasonably setting the focal length of the third lens is beneficial to further converging the light rays, enabling the converged light rays to smoothly enter the rear optical system, reducing the difficulty of correcting the peripheral field distortion, and improving the overall imaging quality. More specifically, 0.56 < f3 / f < 0.93.

[0079] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -5.6 < f4 / f < -0.5. Meeting the above range, by reasonably setting the focal length of the fourth lens, the positive spherical aberration generated by the fourth negative lens can be balanced with the negative spherical aberration generated by the previous positive lenses, improving the overall imaging quality. At the same time, the trend of light can be reasonably controlled to avoid the problem of excessive lens sensitivity caused by excessive light deflection. More specifically, -5.09 < f4 / f < -0.61.

[0080] In some embodiments, the effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: 1 < f12 / f < 4.1. Meeting the above range, by reasonably limiting the focal length of the lens group in front of the aperture, the incident light can be converged, and more light can enter the system, which is beneficial to increasing the light input of the lens and enabling the lens to achieve high-definition imaging in a relatively dark environment. More specifically, 1.16 < f12 / f < 3.82.

[0081] In some embodiments, the curvature radius R11 of the object side surface of the sixth lens and the focal length f6 of the sixth lens satisfy: 0.1 < R11 / f6 < 4.6. Meeting the above range, controlling the surface shape of the object side surface of the sixth lens is beneficial to increasing the imaging area and the field angle of the optical lens, balancing the aberration of the optical lens, and improving the imaging quality of the optical lens. More specifically, 0.21 < R11 / f6 < 4.13.

[0082] In some embodiments, the focal length f4 of the fourth lens and the focal length f6 of the sixth lens satisfy: 0.3 < f4 / f6 < 8.1. Meeting the above range is beneficial to the smooth transition of light, while correcting various aberrations of the optical lens and improving the imaging quality of the optical lens. More specifically, 0.36 < f4 / f6 < 7.4.

[0083] In some embodiments, the focal length f5 of the fifth lens and the curvature radius R9 of the object side surface of the fifth lens satisfy: f5 / R9 > 1; the focal length f5 of the fifth lens and the curvature radius R10 of the image side surface of the fifth lens satisfy: f5 / R10 > 0.1. Meeting the above range can limit the surface shapes of the object side and the image side of the fifth lens, have the characteristic of correcting field curvature, and are beneficial to the correction of the aberration of the entire optical lens. More specifically, f5 / R9 > 1.18; f5 / R10 > 0.16.

[0084] In some embodiments, the optical lens satisfies the following conditional expressions: 11.2 mm < f < 17.6 mm; 26° < FOV < 34°; 5.9 mm < EPD < 8.8 mm; 29 mm < TTL < 37 mm; 1.7 < Fno < 2.4; 6.2 mm < IH < 10.2 mm; 12.7° < CRA < 22.8°; 4 mm < BFL < 6.4 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, FNO represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, CRA represents the chief ray angle of incidence of the optical lens, and BFL represents the back focal length 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, 12.45 mm < f < 16.05 mm; 6.55 mm < EPD < 8.03 mm; 30.99 mm < TTL < 35.01 mm; 1.89 < Fno < 2.21; 14.09° < CRA < 20.75°; 4.4 mm < BFL < 5.86 mm; 27.99° < FOV < 32.01°; 6.94 mm < IH < 9.23 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. Additionally, 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, and the sixth 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 achieving 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.

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

[0088] Example 1

[0089] Please see Figure 1 The diagram shown is a schematic diagram of the structure of the optical lens provided in Embodiment 1 of the present invention. The optical lens 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, a filter G1, and a protective glass G2.

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

[0091] The second lens L2 has positive optical power, its object side S3 is concave, and its image side S4 is convex.

[0092] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is convex.

[0093] The fourth lens L4 has negative optical power, its object side S6 is concave, and its image side S7 is convex.

[0094] The third lens L3 and the fourth lens L4 form a cemented lens group with positive optical power, that is, the cemented surface of the image side of the third lens L3 and the object side of the fourth lens L4 is S6.

[0095] The fifth lens L5 has positive optical power, its object side S8 is convex, and its image side S9 is concave.

[0096] The sixth lens L6 has negative optical power, its object side S10 is concave, and its image side S11 is concave.

[0097] The object-side surface S12 and the image-side surface S13 of the filter G1 are both planar.

[0098] The object side S14 and image side S15 of the protective glass G2 are both flat.

[0099] The imaging plane S16 is a plane.

[0100] 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.

[0101] The relevant parameters of each lens in the optical lens of Example 1 are shown in Table 1-1.

[0102] Table 1-1

[0103]

[0104]

[0105] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 2 , Figure 3 As shown.

[0106] Figure 2 The F-Tan (Theta) distortion curve of Example 1 is shown, which represents 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 of view (unit: °). As can be seen from the figure, the distortion of the optical lens is controlled within ±0.5%, indicating that the optical lens can effectively correct distortion.

[0107] Figure 3 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 0.35 throughout the entire field of view. Within the range of 0–240 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.

[0108] Example 2

[0109] Please see Figure 4 The figure shows a schematic diagram of the optical lens provided in Embodiment 2 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 object side surface S5 of the third lens L3 is a concave surface; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0110] The relevant parameters of each lens in the optical lens of Example 2 are shown in Table 2-1.

[0111] Table 2-1

[0112]

[0113]

[0114] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 5 , Figure 6 As shown.

[0115] from Figure 5 As can be seen, the distortion of the optical lens is controlled within ±2%, indicating that the optical lens can effectively correct distortion. From... Figure 6 As can be seen, the MTF value of this embodiment is above 0.25 throughout the entire field of view. In the range of 0 to 240 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.

[0116] Example 3

[0117] Please see Figure 7 The figure shows a schematic diagram of the optical lens provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side surface S11 of the sixth lens L6 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0118] The relevant parameters of each lens in the optical lens of Example 3 are shown in Table 3-1.

[0119] Table 3-1

[0120]

[0121]

[0122] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 8 , Figure 9 As shown.

[0123] from Figure 8 As can be seen, the distortion of the optical lens is controlled within ±2%, indicating that the optical lens can effectively correct distortion. From... Figure 9 As can be seen, the MTF value of this embodiment is above 0.2 throughout the entire field of view. In the range of 0 to 240 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.

[0124] Example 4

[0125] Please see Figure 10The diagram shows a schematic of the optical lens provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the object-side surface S1 of the first lens L1 is concave; the image-side surface S2 of the first lens L1 is convex; the object-side surface S3 of the second lens L2 is convex; the image-side surface S4 of the second lens L2 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.

[0126] The relevant parameters of each lens in the optical lens of Example 4 are shown in Table 4-1.

[0127] Table 4-1

[0128]

[0129]

[0130] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 11 , Figure 12 As shown.

[0131] from Figure 11 As can be seen, the distortion of the optical lens is controlled within ±2%, indicating that the optical lens can effectively correct distortion. From... Figure 12 As can be seen, the MTF value of this embodiment is above 0.25 throughout the entire field of view. In the range of 0 to 240 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.

[0132] Example 5

[0133] Please see Figure 13 The figure shows a schematic diagram of the optical lens 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 object-side surface S5 of the third lens L3 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.

[0134] The relevant parameters of each lens in the optical lens of Example 5 are shown in Table 5-1.

[0135] Table 5-1

[0136]

[0137]

[0138] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 14 , Figure 15 As shown.

[0139] from Figure 14 As can be seen, the distortion of the optical lens is controlled within ±1.5%, indicating that the optical lens can effectively correct distortion. From... Figure 15 As can be seen, the MTF value of this embodiment is above 0.28 throughout the entire field of view. In the range of 0 to 240 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.

[0140] Example 6

[0141] Please see Figure 16 The figure shows a schematic diagram of the optical lens provided in Embodiment 6 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.

[0142] The relevant parameters of each lens in the optical lens of Example 6 are shown in Table 6-1.

[0143] Table 6-1

[0144]

[0145]

[0146] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 17 , Figure 18 As shown.

[0147] from Figure 17 As can be seen, the distortion of the optical lens is controlled within ±2%, indicating that the optical lens can effectively correct distortion. From... Figure 18 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 240 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.

[0148] Example 7

[0149] Please see Figure 19The diagram shows a schematic of the optical lens provided in Embodiment 7 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the third lens L3 and the fourth lens L4 form a cemented lens group with negative optical power; the image-side surface S6 of the third lens L3 is concave; the object-side surface S6 of the fourth lens L4 is convex; the image-side surface S7 of the fourth lens L4 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.

[0150] The relevant parameters of each lens in the optical lens of Example 7 are shown in Table 7-1.

[0151] Table 7-1

[0152]

[0153]

[0154] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens are respectively as follows: Figure 20 , Figure 21 As shown.

[0155] from Figure 20 As can be seen, the distortion of the optical lens is controlled within ±2.5%, indicating that the optical lens can effectively correct distortion. From... Figure 21 As can be seen, the MTF value of this embodiment is above 0.28 throughout the entire field of view. In the range of 0 to 240 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.

[0156] Please refer to Table 12 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0157] Table 12

[0158]

[0159]

[0160] In summary, the optical lens provided by the present 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 long focal length, large target surface, and high imaging quality.

[0161] 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.

[0162] 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, characterized in that, It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with a positive optical power; A second lens with a positive optical power; A third lens with a positive optical power; A fourth lens with a negative optical power; A fifth lens with a positive optical power, whose object side is convex and whose image side is concave; A sixth lens with a negative optical power, whose object side is concave; Wherein, the radius of curvature R10 of the image side of the fifth lens and the radius of curvature R11 of the object side of the sixth lens satisfy: 0 < (R10 + R11) / (R10 - R11) < 1.

2. The optical lens according to claim 1, characterized in that, The maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 12° < FOV / Fno < 17.5°; The total optical length TTL of the optical lens, the maximum field angle FOV of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 85 < 180° × TTL / IH / FOV < 119.

3. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: f5 / f > 0.

6.

4. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.7 < f6 / f < -0.

4.

5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the radius of curvature R9 of the object side of the fifth lens satisfy: 0.4 < R9 / f < 1.

6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the radius of curvature R10 of the image side of the fifth lens satisfy: 0.5 < R10 / f < 7.

7. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the radius of curvature R11 of the object side of the sixth lens satisfy: -2.7 < R11 / f < -0.

3.

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: 0.2 < R3 / R4 < 1.1; The radius of curvature R7 of the object side of the fourth lens and the radius of curvature R8 of the image side of the fourth lens satisfy: 0.4 < R7 / R8 < 8.

3.

9. The optical lens according to claim 1, characterized in that, The radius of curvature R9 of the object side of the fifth lens and the radius of curvature R10 of the image side of the fifth lens satisfy: |(R9 - R10) / (R9 + R10)| < 0.

9.

10. The optical lens according to claim 1, characterized in that, The sagittal height Sag10 of the image side clear aperture of the fifth lens and the clear aperture diameter d10 of the image side of the fifth lens satisfy: 0 < Sag10 / d10 < 0.3; The sagittal height Sag11 of the object side clear aperture of the sixth lens and the clear aperture diameter d11 of the object side of the sixth lens satisfy: -0.4 < Sag11 / d11 < 0.

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