Optical lens

Abstract

The present invention provides an optical lens, which consists of six lenses, sequentially arranged from the object side to the imaging surface along the optical axis, including: a first lens with negative refractive power, whose image side surface is a concave surface; a second lens with negative refractive power, whose object side surface is a concave surface near the optical axis; a third lens with positive refractive power, whose object side surface is a convex surface; a fourth lens with positive refractive power, whose image side surface is a convex surface; a fifth lens with positive refractive power, whose object side surface is a concave surface near the optical axis, and whose image side surface is a convex surface near the optical axis; a sixth lens with positive refractive power, whose object side surface is a convex surface near the optical axis, and whose image side surface is a concave surface near the optical axis. The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.5<TTL / f<2.5. The optical lens provided by the present invention has the advantages of miniaturization, large aperture, large imaging surface, long focal length and the like through specific surface shape matching and reasonable refractive power distribution.

Description

Technical Field

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

[0002] With the continuous development and application of automotive intelligent technology, the use of automotive cameras is becoming increasingly widespread. To achieve more accurate recognition results, the number of automotive cameras installed in each car has increased from 2 to 3 to more than 7. The domestic market share of automotive cameras reached 6.6 billion yuan in 2020. With the rapid development of automotive intelligent technology, the market share of automotive cameras in China is expected to exceed 23 billion yuan by 2025, indicating an extremely broad market prospect.

[0003] Currently, the automotive camera market is dominated by exterior lenses, while interior lenses have a relatively low but rapidly growing share. The interior lenses used for fatigue monitoring are relatively conventional, with small apertures, long overall lengths, and blurry nighttime images, which are not conducive to normal operation in dimly lit environments inside the vehicle. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an optical lens with advantages such as a large aperture, short overall length, and high-definition imaging at night.

[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] The first lens with negative optical power has a concave image-side surface.

[0008] The second lens with negative optical power has a concave object-side surface near the optical axis.

[0009] A third lens with positive optical power has a convex object-side surface;

[0010] The fourth lens has positive optical power and its image-side surface is convex.

[0011] The fifth lens with positive optical power has an object-side surface that is concave near the optical axis and an image-side surface that is convex near the optical axis.

[0012] The sixth lens with positive optical power has an object-side surface that is convex near the optical axis and an image-side surface that is concave near the optical axis.

[0013] Wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.5 <TTL / f<2.5。

[0014] Further preferably, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.2<IH / f<1.6.

[0015] Further preferably, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 1<TTL / IH<2.

[0016] Further preferably, the effective focal length f of the optical lens and the aperture value Fno of the optical lens satisfy: 4mm<f / Fno<6mm.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -20<f1 / f<-3.

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -50<f2 / f<-2; the curvature radius R3 of the object-side surface of the second lens and the effective focal length f of the optical lens satisfy: -5<R3 / f<-0.5.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1<f3 / f<3.5.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1<f4 / f<3.

[0021] Further preferably, the curvature radius R11 of the object-side surface of the sixth lens and the curvature radius R12 of the image-side surface of the sixth lens satisfy: 0.8<R11 / R12<2; the curvature radius R12 of the image-side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 0.1<R12 / f<1.

[0022] Further preferably, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -15<f2 / f3<-1; the focal length f4 of the fourth lens and the focal length f5 of the fifth lens satisfy: 0.03<f4 / f5<0.3.

[0023] Further preferably, the effective aperture DM1 of the object-side surface of the first lens and the effective aperture DM3 of the object-side surface of the third lens satisfy: 1.1<DM1 / DM3<1.35; the effective aperture DM3 of the object-side surface of the third lens and the effective aperture DM6 of the object-side surface of the sixth lens satisfy: 1.1<DM6 / DM3<1.4.

[0024] Compared to existing technologies, the optical lens provided by this invention, through specific surface shape settings and reasonable power distribution, possesses telephoto characteristics, enabling it to better present larger local details and make the image more focused and compact, thus meeting the needs of local shooting. It also achieves the large image plane characteristic of the lens, allowing for the integration of larger-sized chips and high-definition imaging. Furthermore, the optical lens of this invention features a compact, large-aperture structure, effectively shortening the overall length of the optical lens and allowing more light to enter, enabling clear imaging even in low-light environments. Simultaneously, the optical lens operates in the infrared band, which can assist infrared light sources to effectively improve nighttime imaging quality. Attached Figure Description

[0025] 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:

[0026] Figure 1 This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0027] Figure 2 This is an astigmatism curve diagram of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 3 This is the F-Tanθ distortion curve of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 4 This is an axial chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 5 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 6 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0032] Figure 7 This is an astigmatism curve of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 8 This is the F-Tanθ distortion curve of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 9 This is an axial chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0035] Figure 10 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0036] Figure 11 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0037] Figure 12 This is an astigmatism curve diagram of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 13 This is the F-Tanθ distortion curve of the optical lens in Embodiment 3 of the present invention.

[0039] Figure 14 This is an axial chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0040] Figure 15 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0041] Figure 16 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0042] Figure 17 This is an astigmatism curve of the optical lens in Embodiment 4 of the present invention.

[0043] Figure 18 This is the F-Tanθ distortion curve of the optical lens in Embodiment 4 of the present invention.

[0044] Figure 19 This is an axial chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0045] Figure 20 This is a chromatic aberration curve of the optical lens in Embodiment 4 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 consists of six lenses, which are arranged sequentially along the optical axis from the object side to the imaging plane as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens.

[0055] In some embodiments, the first lens may have negative optical power, and the image side thereof is a concave surface. The second lens may have negative optical power, and the object side thereof is a concave surface at the paraxial region. The third lens may have positive optical power, and the object side thereof is a convex surface. The fourth lens may have positive optical power, and the image side thereof is a convex surface. The fifth lens may have positive optical power, the object side thereof is a concave surface at the paraxial region, and the image side thereof is a convex surface at the paraxial region. The sixth lens may have positive optical power, the object side thereof is a convex surface at the paraxial region, and the image side thereof is a concave surface at the paraxial region.

[0056] In some embodiments, the optical lens may further include a stop for limiting the light beam. The stop may be disposed between the second lens and the third lens, which can reduce the generation of ghost images of the optical lens, and at the same time effectively reduce the difficulty of distortion correction of the lens.

[0057] In some embodiments, the optical lens may further include a filter and a protective glass. The filter and the protective glass may be sequentially disposed between the sixth lens and the imaging surface along the optical axis. The filter is used to filter out interfering light, preventing the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging. The protective glass functions to protect the optical lens, can improve the impact resistance and scratch resistance of the optical lens, and has almost no effect on the imaging quality of the optical lens at the same time.

[0058] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.5<TTL / f<2.5. Satisfying the above conditions, by reasonably setting the ratio of the total optical length to the effective focal length of the optical lens, not only can the length of the lens be effectively limited to realize the miniaturization of the optical lens, but also it is beneficial for the light to better converge on the imaging surface, so as to improve the imaging quality of the lens.

[0059] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.2<IH / f<1.6. Satisfying the above conditions can not only realize the telephoto characteristic of the lens to meet the demand for partial shooting, but also realize the large image plane characteristic of the lens, which can match a chip of a larger size and realize high-pixel imaging of the lens.

[0060] In some embodiments, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 1<TTL / IH<2. Satisfying the above conditions, by reasonably limiting the ratio of the total optical length to the image height of the optical lens, the total optical length can be shortened while realizing large target surface imaging, the balance between the miniaturization of the optical lens and large target surface imaging is achieved, and the market competitiveness is improved.

[0061] In some embodiments, the effective focal length f of the optical lens and the aperture value Fno of the optical lens satisfy: 4mm<f / Fno<6mm. Meeting the above conditions is conducive to expanding the aperture of the optical lens while achieving the telephoto performance of the lens, so that the lens can achieve high-definition imaging even in a dim environment at night (assisted by an infrared light source).

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -20<f1 / f<-3. Meeting the above conditions enables the first lens to effectively collect incident light information to achieve wide-angle characteristics, while balancing the relationship between the working aperture and the field of view of the first lens, so that the lens achieves a large field of view with a relatively small aperture.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -50<f2 / f<-2. Meeting the above conditions facilitates the smooth transition of light rays, can effectively balance the aberration caused by the negative refractive power of the first lens, and improve the imaging resolution.

[0064] In some embodiments, the curvature radius R3 of the object-side surface of the second lens and the effective focal length f of the optical lens satisfy: -5<R3 / f<-0.5. Meeting the above conditions, by reasonably setting the shape of the second lens, is conducive to converging light rays, balancing the aberration introduced by the first lens, reducing the difficulty of distortion correction, preventing the image of the lens at the edge field of view from distortion, and improving the imaging quality of the optical system

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1<f3 / f<3.5. Meeting the above conditions enables the third lens to bear a relatively large positive refractive power, which is conducive to accelerating the deflection trend of light rays and promoting the structural miniaturization of the optical lens.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1<f4 / f<3. Meeting the above conditions, by reasonably setting the optical power of the fourth lens, facilitates the smooth transition of light rays, balances various aberrations generated by the fourth lens itself, and improves the imaging quality of the optical system.

[0067] In some embodiments, the curvature radius R11 of the object-side surface of the sixth lens and the curvature radius R12 of the image-side surface of the sixth lens satisfy: 0.8<R11 / R12<2; the curvature radius R12 of the image-side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 0.1<R12 / f<1. Meeting the above conditions, by reasonably setting the shape of the sixth lens, can accelerate the deflection of light rays, so as to increase the focusing height of light rays, and at the same time help to increase the photosensitive area of the image plane, effectively improving the imaging quality of the optical lens.

[0068] In some embodiments, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -15<f2 / f3<-1. Satisfying the above conditions, by reasonably setting the focal length ratio of the lenses before and after the diaphragm, it is beneficial to the gentle transition of light, reduces the difficulty of distortion correction, and improves the overall imaging quality.

[0069] In some embodiments, the focal length f4 of the fourth lens and the focal length f5 of the fifth lens satisfy: 0.03<f4 / f5<0.3. Satisfying the above conditions, by reasonably setting the focal length ratio of the fourth lens and the fifth lens, it is beneficial to correct the on-axis aberration of the optical lens and improve the imaging quality of the optical lens; at the same time, it can also improve the angle of ghost light between the fourth lens and the fifth lens, and reduce ghost energy.

[0070] In some embodiments, the effective aperture DM1 of the object side of the first lens and the effective aperture DM3 of the object side of the third lens satisfy: 1.1<DM1 / DM3<1.35; the effective aperture DM3 of the object side of the third lens and the effective aperture DM6 of the object side of the sixth lens satisfy: 1.1<DM6 / DM3<1.4. Satisfying the above conditions is beneficial to increasing the light throughput of the system while reducing the loss of light entering and exiting the system, enabling the system to perform high-definition imaging in low-light or even dim environments while also improving the response speed of the system, so as to better achieve the large-aperture imaging effect of the lens.

[0071] In some embodiments, the effective focal length f of the optical lens, the maximum field of view angle FOV, and the image height IH corresponding to the maximum field of view angle satisfy: 40°<(f×FOV) / IH<55°. Satisfying the above conditions, by reasonably limiting the relationship among the focal length, the field of view angle and the image height of the optical lens, it is beneficial to achieve the balance between the long focal length and large target surface imaging of the optical lens.

[0072] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 5<f5 / f<60. Satisfying the above conditions, by reasonably setting the focal length of the fifth lens, it is beneficial to further converge the light, reduce the angle between the chief ray of the marginal field of view and the optical axis, so as to reduce the spot diameter and improve aberration; at the same time, it can also increase the imaging area of the optical lens and improve the imaging quality of the optical lens.

[0073] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 4<f6 / f<50. Satisfying the above conditions, by reasonably setting the focal length of the sixth lens, the deflection of light can be accelerated, so as to increase the focusing height of the light, and at the same time help to increase the photosensitive area of the image plane, effectively improving the imaging quality of the optical lens.

[0074] In some embodiments, the curvature radius R9 of the object-side surface of the fifth lens and the curvature radius R10 of the image-side surface of the fifth lens satisfy: 0.2<R9 / R10<2; and the curvature radius R9 of the object-side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -1<R9 / f<-0.05. By satisfying the above conditions, the meniscus shape of the fifth lens is reasonably arranged, which can accelerate the convergence of light rays, reduce the difficulty of correcting marginal aberrations, and effectively improve the imaging quality of the optical lens.

[0075] In some embodiments, the curvature radius R8 of the image-side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -1.5<R8 / f<-0.5. Satisfying the above conditions is beneficial to balancing various aberrations of the lens, improving the imaging quality of the optical lens, while reducing the processing difficulty of the fourth lens and improving the machinability.

[0076] In some embodiments, the central thickness CT5 of the fifth lens along the optical axis and the central thickness CT6 of the sixth lens along the optical axis satisfy: 0.5<CT5 / CT6<0.8. Satisfying the above conditions is beneficial to the gentle transition of light rays and improves the image quality.

[0077] In some embodiments, the total optical length TTL of the optical lens and the separation distance CT45 between the fourth lens and the fifth lens along the optical axis satisfy: 0.15<CT45 / TTL<0.25. Satisfying the above conditions is beneficial to the gentle transition of light rays, reduces the sensitivity of the optical system, and realizes the compact structure of the optical system at the same time.

[0078] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens may be spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberrations of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens and the third lens of the present invention may adopt spherical lenses, and the second lens, the fourth lens, the fifth lens, and the sixth lens may adopt aspherical lenses.

[0079] In some embodiments, the material of the lenses in the optical lens provided by the present invention may be glass or plastic. When the material of the lens is plastic, the production cost can be effectively reduced. In addition, when the material of the lens is glass, the geometric chromatic aberration of the optical system can be effectively corrected by utilizing the low dispersion characteristic of the glass itself. The optical lens provided by the present invention includes at least one glass lens and one plastic lens. By adopting a hybrid collocation of six glass and plastic lenses, it can have good thermal stability on the premise of meeting high pixels, and can reduce the cost. More specifically, the first lens and the third lens of the present invention may be glass lenses, and the second lens, the fourth lens, the fifth lens, and the sixth lens may be plastic lenses.

[0080] In some embodiments, the optical lens satisfies the conditional expressions: 11mm<TTL<14mm, 5mm<f<8mm, 7.5mm<IH<9.5mm, Fno<1.5, 60°<FOV<75°; where TTL denotes the total optical length of the optical lens, f denotes the effective focal length of the optical lens, IH denotes the real image height corresponding to the maximum field of view of the optical lens, Fno denotes the aperture value of the optical lens, and FOV denotes the maximum field of view of the optical lens. Satisfying the above conditions indicates that the optical lens provided by the embodiments of the present invention at least has the characteristics of large image height, telephoto property, large aperture and miniaturization.

[0081] In various embodiments of the present invention, when aspheric lenses are adopted as the lenses, each aspheric surface shape of the optical lens satisfies the following equation:

[0082]

[0083] where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and B, C, D, E, F, G, H are respectively the 4th-order, 6th-order, 8th-order, 10th-order, 12th-order, 14th-order and 16th-order surface coefficients.

[0084] The present invention will be further described below with reference to a plurality of embodiments. In each embodiment, the thickness, curvature radius and material selection part of each lens in the optical lens are partially different, and the specific differences can be referred to the parameter tables of the respective embodiments. The following embodiments are only preferred implementations of the present invention, but the implementations of the present invention are not limited to the following embodiments. Any other changes, substitutions, combinations or simplifications made without departing from the innovative points of the present invention shall be regarded as equivalent replacement manners, and all shall fall within the protection scope of the present invention.

[0085] Embodiment 1

[0086] Please refer to Figure 1 , which shows a schematic structural diagram of the optical lens 100 provided in Embodiment 1 of the present invention. Along the optical axis from the object side to the imaging surface, the optical lens sequentially includes: a first lens L1, a second lens L2, a diaphragm ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, an optical filter G1, and a protective glass G2.

[0087] wherein the first lens L1 has negative refractive power, its object side surface S1 is a convex surface, and its image side surface S2 is a concave surface;

[0088] the second lens L2 has negative refractive power, its object side surface S3 is a concave surface at the position close to the optical axis, and its image side surface S4 is a convex surface at the position close to the optical axis;

[0089] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is concave.

[0090] The fourth lens L4 has positive optical power, and both its object-side surface S7 and image-side surface S8 are convex.

[0091] The fifth lens L5 has positive optical power, its object side S9 is concave near the optical axis, and its image side S10 is convex near the optical axis.

[0092] The sixth lens L6 has positive optical power, its object side S11 is convex near the optical axis, and its image side S12 is concave near the optical axis.

[0093] The object-side surface S13 and the image-side surface S14 of filter G1 are both planar.

[0094] The object side S15 and the image side S16 of the protective glass G2 are both flat.

[0095] The imaging plane S17 is a plane.

[0096] The first lens L1 and the third lens L3 are glass spherical lenses, while the second lens L2, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are plastic aspherical lenses.

[0097] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0098] Table 1-1

[0099]

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

[0101] Table 1-2

[0102]

[0103] In this embodiment, the astigmatism curve, F-Tanθ distortion curve, axial chromatic aberration curve, and transverse chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown.

[0104] Figure 2The astigmatism curves for Example 1 are shown, representing the astigmatism of light with a wavelength (0.940 μm) in the meridional and sagittal image planes. The horizontal axis represents the offset (in mm), and the vertical axis represents the field of view (in °). As can be seen from the figure, the astigmatism in both the meridional and sagittal image planes is controlled within ±0.2 mm, indicating that the optical lens 100 can effectively correct astigmatism.

[0105] Figure 3 The F-Tanθ distortion curve of Example 1 is shown, which represents the F-Tanθ distortion of light with a wavelength (0.940 μm) at different image heights on the imaging plane. The horizontal axis represents the F-Tanθ distortion value (unit: %), and the vertical axis represents the field of view (unit: °). As can be seen from the figure, the F-Tanθ distortion of the optical lens 100 is controlled within ±5%, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0106] Figure 4 The axial chromatic aberration curve of Example 1 is shown, which represents the chromatic aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial chromatic aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial chromatic aberration offset is controlled within ±0.04 mm, indicating that the optical lens 100 can effectively correct the axial chromatic aberration.

[0107] 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 (0.940 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 ±1.5 μm, indicating that the optical lens 100 can effectively correct chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane.

[0108] Example 2

[0109] Please see Figure 6 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 object side S1 of the first lens L1 is concave, the image side S6 of the third lens L3 is convex, 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 200 in Example 2 are shown in Table 2-1.

[0111] Table 2-1

[0112]

[0113]

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

[0115] Table 2-2

[0116]

[0117] In this embodiment, the astigmatism curve, F-Tanθ distortion curve, axial chromatic aberration curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown. From Figure 7 As can be seen, the astigmatism in the meridional and sagittal image planes of optical lens 200 is controlled within ±0.4mm, indicating that optical lens 200 can effectively correct astigmatism. From Figure 8 As can be seen, the F-Tanθ distortion of the 200mm optical lens is controlled within ±5%, and the image compression in the edge angle area is relatively smooth, effectively improving the sharpness of the unfolded image. From Figure 9 As can be seen, the axial chromatic aberration offset is controlled within ±0.03mm, indicating that the optical lens 200 can effectively correct axial chromatic aberration. From Figure 10 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1.2μm, indicating that the optical lens 200 can correct the chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane very well.

[0118] Example 3

[0119] Please see Figure 11 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 S4 of the second lens L2 is concave, the image-side surface S6 of the third lens L3 is convex, and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0120] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0121] Table 3-1

[0122]

[0123] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0124] Table 3-2

[0125] Face number K B C D E F G H S3 -3.0000E+02 2.7475E-04 7.2463E-04 -6.5290E-05 -1.2785E-05 1.9966E-06 -6.2708E-08 -1.1159E-09 S4 -2.1163E+02 9.9621E-03 -1.2809E-04 4.4072E-05 8.5076E-06 -5.7501E-06 6.5986E-07 -1.3752E-08 S7 -3.0000E+02 2.7875E-03 -4.1421E-04 3.4752E-05 -6.4618E-06 -3.2576E-07 1.3434E-07 -6.1502E-09 S8 6.2280E-01 -3.8435E-04 -2.0453E-04 -5.1217E-06 1.3542E-06 1.4112E-07 -5.4660E-08 4.1700E-09 S9 -3.2423E+00 -9.7602E-04 -6.1597E-03 1.7231E-03 -1.3927E-04 -1.2393E-06 7.8003E-07 -3.4034E-08 S10 -4.7904E+00 -3.3368E-02 8.1591E-03 -1.4660E-03 1.4762E-04 3.8283E-06 -1.7531E-06 9.1805E-08 S11 -3.8569E+00 -1.2842E-02 1.5733E-03 -1.8167E-04 7.8040E-06 2.4515E-07 -5.5277E-08 2.4311E-09 S12 -4.5555E+00 -5.2220E-03 3.4559E-04 -3.1909E-05 5.6597E-07 6.7784E-08 -4.8292E-09 1.0601E-10

[0126] In this embodiment, the astigmatism curve, F-Tanθ distortion curve, axial chromatic aberration curve, and transverse chromatic aberration curve of the optical lens 300 are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown. From Figure 12 As can be seen, the astigmatism in the meridional and sagittal image planes of optical lens 300 is controlled within ±0.2mm, indicating that optical lens 300 can effectively correct astigmatism. From Figure 13 As can be seen, the F-Tanθ distortion of the 300mm optical lens is controlled within ±5%, and the image compression in the edge angle area is relatively smooth, effectively improving the sharpness of the unfolded image. From Figure 14 As can be seen, the axial chromatic aberration offset is controlled within ±0.04mm, indicating that the optical lens 300 can effectively correct axial chromatic aberration. From Figure 15 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1.5μm, indicating that the optical lens 300 can correct the chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane very well.

[0127] Example 4

[0128] Please see Figure 16 The figure shows a schematic diagram 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 object side S1 of the first lens L1 is concave; the image side S6 of the third lens L3 is convex; the object side S7 of the fourth lens L4 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0129] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0130] Table 4-1

[0131]

[0132]

[0133] The surface profile parameters of the aspherical lens in Example 4 are shown in Table 4-2.

[0134] Table 4-2

[0135]

[0136] In this embodiment, the astigmatism curve, F-Tanθ distortion curve, axial chromatic aberration curve, and transverse chromatic aberration curve of the optical lens 400 are respectively as follows: Figure 17 , Figure 18 , Figure 19 , Figure 20 As shown. From Figure 17 As can be seen, the astigmatism in the meridional and sagittal image planes of optical lens 400 is controlled within ±0.35mm, indicating that optical lens 400 can effectively correct astigmatism. From Figure 18 As can be seen, the F-Tanθ distortion of the 400mm optical lens is controlled within ±4.5%, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image. From Figure 19 As can be seen, the axial chromatic aberration offset is controlled within ±0.035mm, indicating that the optical lens 400 can effectively correct axial chromatic aberration. From Figure 20 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1.1μm, indicating that the optical lens 400 can correct the chromatic aberration at the edge of the field of view and the secondary spectrum of the entire image plane very well.

[0137] Please refer to Table 5 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.

[0138] Table 5

[0139]

[0140]

[0141] In summary, the optical lens provided by the present invention has at least the following advantages:

[0142] (1) The lens has a telephoto feature, which can better present larger local details, making the picture more focused and compact, thus meeting the needs of local shooting; it can also realize the large image plane feature of the lens, and can carry a larger chip to achieve high-definition imaging.

[0143] (2) It has a compact large aperture structure, which effectively shortens the overall length of the optical lens and allows more light to enter the optical lens, so that the system can also form clear images in dim environments; at the same time, the optical lens operates in the infrared band, which can assist the infrared light source to effectively improve the imaging quality at night.

[0144] (3) The glass-plastic hybrid structure is adopted, which enhances the light transmittance, optimizes the lens offset at different temperatures, and can have good thermal stability while meeting the requirements of high pixel count, and can reduce costs.

[0145] 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.

[0146] 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, Sequentially arranged along the optical axis from the object side to the imaging surface, the optical system comprises: a first lens with negative optical power, whose image-side surface is a concave surface; a second lens with negative optical power, whose object-side surface is a concave surface at a position near the optical axis; a third lens with positive optical power, whose object-side surface is a convex surface; a fourth lens with positive optical power, whose image-side surface is a convex surface; a fifth lens with positive optical power, whose object-side surface is a concave surface at a position near the optical axis, and whose image-side surface is a convex surface at a position near the optical axis; a sixth lens with positive optical power, whose object-side surface is a convex surface at a position near the optical axis, and whose image-side surface is a concave surface at a position near the optical axis; wherein the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.5<TTL / f<2.

5.

2. The optical lens according to claim 1, characterized in that, The real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.2<IH / f<1.

6.

3. The optical lens according to claim 1, characterized in that, The total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 1<TTL / IH<2.

4. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the F-number Fno of the optical lens satisfy: 4mm<f / Fno<6mm.

5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -20<f1 / f<-3.

6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -50<f2 / f<-2; the curvature radius R3 of the object-side surface of the second lens and the effective focal length f of the optical lens satisfy: -5<R3 / f<-0.

5.

7. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1<f3 / f<3.

5.

8. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1<f4 / f<3.

9. The optical lens according to claim 1, characterized in that, The curvature radius R11 of the object-side surface of the sixth lens and the curvature radius R12 of the image-side surface of the sixth lens satisfy: 0.8<R11 / R12<2; the curvature radius R12 of the image-side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 0.1<R12 / f<1.

10. The optical lens according to claim 1, characterized in that, The focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -15<f2 / f3<-1; the focal length f4 of the fourth lens and the focal length f5 of the fifth lens satisfy: 0.03<f4 / f5<0.

3.

11. The optical lens according to claim 1, characterized in that, The effective clear aperture DM1 of the object-side surface of the first lens and the effective clear aperture DM3 of the object-side surface of the third lens satisfy: 1.1<DM1 / DM3<1.35; the effective clear aperture DM3 of the object-side surface of the third lens and the effective clear aperture DM6 of the object-side surface of the sixth lens satisfy: 1.1<DM6 / DM3<1.4.

Images