Optical lens

Abstract

The application provides an optical lens, which comprises eight lenses in sequence along an optical axis from an object side to an imaging surface, and the eight lenses comprise: a first lens with positive focal power, wherein the object side of the first lens is a convex surface, and the image side of the first lens is a concave surface; a second lens with positive focal power, wherein the object side of the second lens is a convex surface, and the image side of the second lens is a concave surface; a third lens with negative focal power, wherein the object side of the third lens is a concave surface, and the image side of the third lens is a concave surface; a fourth lens with positive focal power, wherein the object side of the fourth lens is a convex surface, and the image side of the fourth lens is a convex surface; a fifth lens with negative focal power, wherein the object side of the fifth lens is a concave surface, and the image side of the fifth lens is a convex surface; a sixth lens with positive focal power, wherein the object side of the sixth lens is a concave surface, and the image side of the sixth lens is a convex surface; a seventh lens with positive focal power, wherein the object side of the seventh lens is a convex surface near the optical axis; and an eighth lens with negative focal power, wherein the object side of the eighth lens is a concave surface. The optical lens provided by the application can improve the imaging quality of the optical lens, reduce aberration and improve the imaging quality of the optical lens.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of imaging lenses, in particular to an optical lens. BACKGROUND

[0002] With the development of security technology in recent years, the target size requirement of monitoring lenses is getting higher and higher. It is well known that the larger the sensor target size is, the better the photosensitive performance is, and the better the imaging effect is. However, most of the large target lenses on the market have the problems of large distortion and poor imaging effect in dark environment. SUMMARY

[0003] In view of the above problems, the present application aims to provide an optical lens with excellent imaging quality.

[0004] The technical scheme adopted by the present application is as follows:

[0005] An optical lens, which comprises eight lenses in sequence along the optical axis from the object side to the imaging surface, comprising:

[0006] a first lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;

[0007] a second lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;

[0008] a third lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface;

[0009] a fourth lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface;

[0010] a fifth lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface;

[0011] a sixth lens with positive refractive power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface;

[0012] a seventh lens with positive refractive power, the object side surface of which is a convex surface near the optical axis;

[0013] an eighth lens with negative refractive power, the object side surface of which is a concave surface;

[0014] wherein the real image height IH corresponding to the maximum field angle of the optical lens and the aperture value Fno of the optical lens satisfy: 8mm<IH / Fno<9mm.

[0015] It is further preferred that the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -0.5 < f1234 / f5678 < -0.3.

[0016] It is further preferred that the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 0.16 < f1 / f2 < 0.2.

[0017] It is further preferred that the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.5 < f1 / f < 1.6.

[0018] It is further preferred that the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 8 < f2 / f < 10.

[0019] It is further preferred that the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -2 < f3 / f < -1.8; the object side surface curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: -3.15 < R5 / f < -2.95.

[0020] It is further preferred that the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.3 < f4 / f < 1.5; the object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: -0.5 < R7 / R8 < -0.3.

[0021] It is further preferred that the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -3 < f5 / f < -1.5; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.3 < f6 / f < 1.8.

[0022] It is further preferred that the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.5 < f7 / f < 2.8; the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -0.85 < f8 / f < -0.6.

[0023] It is further preferred that the center thickness CT7 of the seventh lens and the center thickness CT8 of the eighth lens satisfy: 3.2 < CT7 / CT8 < 3.8.

[0024] Compared with the prior art, the optical lens provided by the application adopts eight lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens is improved, the aberration is reduced, and the imaging quality of the optical lens is improved, so that the lens has one or more advantages of a large image surface, a large aperture, small distortion, high definition and the like. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which:

[0026] Figure 1 It is a structural schematic diagram of the optical lens in embodiment 1 of the application.

[0027] Figure 2 It is an astigmatism curve diagram of the optical lens in embodiment 1 of the application.

[0028] Figure 3 It is an F-Tan(Theta) distortion curve diagram of the optical lens in embodiment 1 of the application.

[0029] Figure 4 It is an axial aberration curve diagram of the optical lens in embodiment 1 of the application.

[0030] Figure 5 It is a curve diagram of the optical lens in embodiment 1 of the application. Axial chromatic aberration.

[0031] Figure 6 It is a structural schematic diagram of the optical lens in embodiment 2 of the application.

[0032] Figure 7 It is an astigmatism curve diagram of the optical lens in embodiment 2 of the application.

[0033] Figure 8 It is an F-Tan(Theta) distortion curve diagram of the optical lens in embodiment 2 of the application.

[0034] Figure 9 It is an axial aberration curve diagram of the optical lens in embodiment 2 of the application.

[0035] Figure 10 It is a curve diagram of the optical lens in embodiment 2 of the application. Axial chromatic aberration.

[0036] Figure 11 It is a structural schematic diagram of the optical lens in embodiment 3 of the application.

[0037] Figure 12 It is an astigmatism curve diagram of the optical lens in embodiment 3 of the application.

[0038] Figure 13A graph of F-Tan(Theta) distortion curve of the optical lens according to Embodiment 3 of the present application.

[0039] Figure 14 A graph of axial aberration curve of the optical lens according to Embodiment 3 of the present application.

[0040] Figure 15 A graph of lateral chromatic aberration curve of the optical lens according to Embodiment 3 of the present application.

[0041] Figure 16 A schematic structural diagram of an optical lens according to Embodiment 4 of the present application.

[0042] Figure 17 A graph of astigmatism curve of the optical lens according to Embodiment 4 of the present application.

[0043] Figure 18 A graph of F-Tan(Theta) distortion curve of the optical lens according to Embodiment 4 of the present application.

[0044] Figure 19 A graph of axial aberration curve of the optical lens according to Embodiment 4 of the present application.

[0045] Figure 20 A graph of lateral chromatic aberration curve of the optical lens according to Embodiment 4 of the present application.

[0046] The following detailed description will further describe the present application with reference to the above drawings. DETAILED DESCRIPTION

[0047] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be noted that these detailed descriptions are only descriptions of embodiments of the present application and are not intended in any way to limit the scope of the present application. Throughout the specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0048] It is to be noted that, in the present specification, the expressions first, second, third, etc. are used only to distinguish one feature from another feature, and do not represent any limitation on the features. Thus, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0049] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical surface or the aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0050] In the present disclosure, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region; if a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the imaging plane is referred to as the image side surface of the lens.

[0051] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. In addition, when expressions such as "at least one of" appear after a list of two or more items, it means that any one of the listed items can be present, and also that a combination of any two or more of the listed items can be present. In addition, when describing embodiments of the present application, the word "may" means "one or more embodiments of the present application". Also, the word "exemplary" is intended to mean an example or an illustration.

[0052] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that the terms should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0053] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0054] The optical lens provided by the embodiments of the present application comprises eight lenses, which are sequentially arranged along the optical axis from the object side to the imaging plane as the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens.

[0055] In some embodiments, the first lens can have positive refractive power, a convex object side surface, and a concave image side surface. The second lens can have positive refractive power, a convex object side surface, and a concave image side surface. The third lens can have negative refractive power, a concave object side surface, and a concave image side surface. The fourth lens can have positive refractive power, a convex object side surface, and a convex image side surface. The fifth lens can have negative refractive power, a concave object side surface, and a convex image side surface. The sixth lens can have positive refractive power, a concave object side surface, and a convex image side surface. The seventh lens can have positive refractive power, a convex object side surface at the paraxial region, and a concave or convex image side surface. The eighth lens can have negative refractive power, a concave object side surface, and a concave or convex image side surface.

[0056] In some embodiments, the optical lens can further include a diaphragm, which can be located between the object side and the first lens. It can be understood that the diaphragm is used to limit the amount of light entering, so as to change the brightness of the imaging.

[0057] In some embodiments, the optical lens can further include a filter, which can be disposed between the eighth lens and the imaging surface. The filter is used to filter out interference light, so as to prevent the interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0058] In some embodiments, the real image height IH corresponding to the maximum field angle of the optical lens and the aperture value Fno of the optical lens satisfy: 8mm<IH / Fno<9mm. Satisfying the above condition, the optical lens can have a larger aperture while having a larger imaging surface, ensuring that the lens also has a larger light flux in a darker environment, and the dark part can retain more imaging details, thereby improving the picture quality of the lens in different environments.

[0059] In some embodiments, the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy: -0.5<f1234 / f5678<-0.3. Satisfying the above condition, by reasonably balancing the focal length relationship of the front and rear lens groups, it is beneficial to balance various aberrations of the lens and improve the overall imaging quality.

[0060] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 0.16<f1 / f2<0.2. Satisfying the above condition, the first and second lenses both provide positive refractive power, and by reasonably matching the focal length relationship of the first and second lenses, the light rays can be further converged, which is beneficial to the further convergence of the incident light and better realizes the balance of the large aperture and the large wide angle of the lens.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.5 < f1 / f < 1.6. Satisfying the above condition, the first lens can have a larger positive refractive power, improve the light collection capability of the edge field of view, and facilitate the realization of large wide-angle imaging of the lens.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 8 < f2 / f < 10. Satisfying the above condition, the second lens can have a proper positive refractive power, facilitate the smooth transition of the light path, improve the imaging quality of the optical lens, and reduce the system sensitivity and improve the manufacturing yield.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -2 < f3 / f < -1.8. Satisfying the above condition, the third lens can have a larger negative refractive power, and can diverge the incident light to a greater extent, thereby effectively improving the height of the light entering the imaging surface and better realizing large target surface imaging of the lens.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -2 < f3 / f < -1.8. Satisfying the above condition, the third lens can have a larger negative refractive power, and can diverge the incident light to a greater extent, thereby effectively improving the height of the light entering the imaging surface and better realizing large target surface imaging of the lens.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.3 < f4 / f < 1.5. Satisfying the above condition, the difficulty of edge field of view distortion correction can be effectively reduced, the lens can have smaller distortion while realizing large field of view, the overall imaging quality can be improved, the system sensitivity can be reduced, and the manufacturing yield can be improved.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.3 < f4 / f < 1.5. Satisfying the above condition, the difficulty of edge field of view distortion correction can be effectively reduced, the lens can have smaller distortion while realizing large field of view, the overall imaging quality can be improved, the system sensitivity can be reduced, and the manufacturing yield can be improved.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -3 < f5 / f < -1.5. Satisfying the above condition, the light of the central field of view can be diverged to a certain extent, and the exit angle of the light of the edge field of view can be reduced by the curvature of the edge field of view, thereby improving the relative luminance of the edge field of view.

[0068] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.3 < f6 / f < 1.8. Satisfying the above condition is conducive to correcting the field curvature and distortion of the optical lens, and improving the imaging quality of the optical lens.

[0069] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.5 < f7 / f < 2.8. Satisfying the above condition is conducive to balancing the astigmatism and field curvature of the optical lens, and improving the imaging quality of the optical lens.

[0070] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -0.85 < f8 / f < -0.6. Satisfying the above condition is conducive to further diverging the incident light, making the peripheral light and the central light turn up to a higher imaging position, better achieving large target surface imaging of the lens, and improving the imaging quality.

[0071] In some embodiments, the central thickness CT7 of the seventh lens and the central thickness CT8 of the eighth lens satisfy: 3.2 < CT7 / CT8 < 3.8. Satisfying the above condition ensures that the lens meets the processing requirements while reducing 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.

[0072] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.3 < TTL / f < 1.38. Satisfying the above condition can effectively limit the length of the lens, which is conducive to realizing the miniaturization of the optical lens.

[0073] In some embodiments, 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: 1.9 < IH / f < 2.05. Satisfying the above condition is conducive to realizing the large image surface characteristic of the optical lens, which can make the lens match the large size photosensitive chip of the camera module, and thereby improve the imaging quality of the optical lens.

[0074] In some embodiments, the object side surface radius of curvature R5 of the third lens and the image side surface radius of curvature R6 of the third lens satisfy: -1.4 < R5 / R6 < -1.3. Satisfying the above condition is conducive to correcting the field curvature, astigmatism and distortion of the optical lens by reasonably setting the double-concave shape of the third lens, thereby ensuring the imaging quality of the optical lens.

[0075] In some embodiments, the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f1234 / f < 1.2. By satisfying the above condition, the object surface light of a wide field angle can be converged into the lens, the edge distortion of the lens can be better corrected, and no large aberration is generated, so that high-quality imaging of the lens can be better achieved.

[0076] In some embodiments, the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: -3.3 < f5678 / f < -2. By satisfying the above condition, the light entering the system can be properly diverged, which is beneficial to improving the height of the light entering the image surface, achieving large target surface imaging of the lens, and balancing the distortion and astigmatism generated by the front lens of the optical lens, and improving the imaging quality of the optical lens.

[0077] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the eighth lens along the optical axis and the total optical length TTL of the optical lens satisfy: 0.52 < ∑CT / TTL < 0.6. By satisfying the above condition, the total length of the optical lens can be effectively compressed, and the structure design and production process of the optical lens are also beneficial.

[0078] In some embodiments, the optical lens satisfies the condition: 8.5mm < f < 9.5mm, 85° < FOV < 95°, 11.5mm < TTL < 12.5mm, 1.9 < Fno < 2.1, 16.5mm < IH < 18mm; wherein f represents the effective focal length of the optical lens, FOV represents the maximum field of view of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, and IH represents the real image height corresponding to the maximum field of view of the optical lens. By satisfying the above condition, it indicates that the lens has a large field of view, can realize a large range of shooting range; it indicates that the lens has a large aperture value, and can realize high-definition imaging even in a dark environment; it indicates that the lens has a large target surface, can match a large target surface imaging chip to realize high-definition imaging, and the increase of the target surface can make the pixel distribution more sparse, effectively reduce the noise even in a dark environment, and the dynamic range will be wider, and more imaging details can be preserved in the dark part, so that a clearer shooting effect can be presented.

[0079] In some embodiments, the lens material in the optical lens provided by the present application can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. When the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass. The optical lens provided by the present application can adopt a full-plastic lens structure, which not only has excellent imaging performance, but also has a compact structure, and can better achieve the balance between miniaturization and high image quality.

[0080] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens can adopt a spherical lens or an aspherical lens. 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, the sixth lens, the seventh lens and the eighth lens can all adopt an aspherical lens, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and the size of the lenses, and better achieving the miniaturization of the lens.

[0081] In various embodiments of the present application, when the lens adopts an aspherical lens, the surface shape of the aspherical lens satisfies the following equation:

[0082] ;

[0083] wherein z is the distance of the curved surface to the vertex of the curved surface in the direction of the optical axis, 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 quadratic surface coefficient, A 2i is the aspherical surface coefficient of the 2i-th order.

[0084] The present application will be further described in the following embodiments. In various embodiments, the thickness, the radius of curvature and the material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present application, but the embodiments of the present application are not limited to the following embodiments, and any changes, substitutions, combinations or simplifications made without departing from the innovative points of the present application should be regarded as equivalent replacement methods, and are included in the protection scope of the present application.

[0085] Embodiment 1

[0086] Please refer to Figure 1Fig. 1 is a structural schematic diagram of an optical lens 100 provided in Embodiment 1 of the present application, which comprises, along an optical axis from an object side to an imaging surface S19, a stop ST, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8 and a filter G1.

[0087] The first lens L1 has positive focal power, the object side S1 is a convex surface, and the image side S2 is a concave surface.

[0088] The second lens L2 has positive focal power, the object side S3 is a convex surface, and the image side S4 is a concave surface.

[0089] The third lens L3 has negative focal power, the object side S5 is a concave surface, and the image side S6 is a concave surface.

[0090] The fourth lens L4 has positive focal power, the object side S7 is a convex surface, and the image side S8 is a convex surface.

[0091] The fifth lens L5 has negative focal power, the object side S9 is a concave surface, and the image side S10 is a convex surface.

[0092] The sixth lens L6 has positive focal power, the object side S11 is a concave surface, and the image side S12 is a convex surface.

[0093] The seventh lens L7 has positive focal power, the object side S13 is a convex surface near the optical axis, and the image side S14 is a convex surface.

[0094] The eighth lens L8 has negative focal power, the object side S15 is a concave surface, and the image side S16 is a concave surface near the optical axis.

[0095] The object side S17 and the image side S18 of the filter G1 are both flat surfaces.

[0096] The imaging surface S19 is a flat surface.

[0097] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7 and the eighth lens L8 are all plastic aspherical lenses.

[0098] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0099] Table 1-1

[0100]

[0101] The surface type parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0102] Table 1-2

[0103]

[0104] In this embodiment, the astigmatism curve, F-Tan(Theta) distortion curve, axial aberration curve, and lateral chromatic aberration curve of the optical lens 100 are shown in FIGS. 1-2A, 1-2B, 1-2C, and 1-2D, respectively. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5

[0105] Figure 2 FIG. 1-2A shows the astigmatism curve of the optical lens 100 in this embodiment, which represents the astigmatism of the light rays on the sagittal image surface and the tangential image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the astigmatism of the sagittal image surface and the tangential image surface is controlled within ±0.1 mm, which shows that the optical lens 100 can better correct the astigmatism.

[0106] Figure 3 FIG. 1-2B shows the F-Tan(Theta) distortion curve of the optical lens 100 in this embodiment, which represents the distortion of different field angles on the imaging surface, the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the distortion value is controlled within ±1%, which shows that the optical lens 100 can better correct the distortion.

[0107] Figure 4 FIG. 1-2C shows the axial aberration curve of the optical lens 100 in this embodiment, which represents the axial aberration of each wavelength on the optical axis at the imaging surface, the horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the offset of the axial aberration is controlled within ±0.03 mm, which shows that the optical lens 100 can better correct the axial aberration.

[0108] Figure 5 FIG. 1-2D shows the lateral chromatic aberration curve of the optical lens 100 in this embodiment, which represents the chromatic aberration of each wavelength at different image heights on the imaging surface relative to the central wavelength (0.555 μm), the horizontal axis represents the lateral chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. As can be seen from the figure, the lateral chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2 μm, which shows that the optical lens 100 can better correct the chromatic aberration.

[0109] Embodiment 2

[0110] Please refer to Figure 6 ​The figure shown is a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side surface S16 of the eighth lens L8 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0111] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0112] Table 2-1

[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-Tan (Theta) distortion curve, axial 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.

[0118] from Figure 7 As can be seen, the astigmatism of the meridional and sagittal image planes is controlled within ±0.1mm, indicating that the optical lens 200 can effectively correct astigmatism.

[0119] from Figure 8 As can be seen, the distortion value is controlled within ±1%, indicating that the optical lens 200 can correct distortion well.

[0120] from Figure 9 As can be seen, the axial aberration offset is controlled within ±0.03mm, indicating that the optical lens 200 can effectively correct axial aberration.

[0121] from Figure 10 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0122] Example 3

[0123] 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 S14 of the seventh lens L7 is concave near the optical axis; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0124] The related parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0125] Table 3-1

[0126]

[0127] The surface type parameters of the aspherical lenses of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0128] Table 3-2

[0129]

[0130] In this embodiment, the astigmatism curve, F-Tan(Theta) distortion curve, axial aberration curve, and transverse aberration curve of the optical lens 300 are shown in Figure 12 、 Figure 13 、 Figure 14 、 Figure 15 respectively.

[0131] As can be seen from Figure 12 , the astigmatism of the meridional image surface and the sagittal image surface is controlled within ±0.1 mm, which shows that the optical lens 300 can correct astigmatism well.

[0132] As can be seen from Figure 13 , the distortion value is controlled within ±1%, which shows that the optical lens 300 can correct distortion well.

[0133] As can be seen from Figure 14 , the offset of the axial aberration is controlled within ±0.02 mm, which shows that the optical lens 300 can correct axial aberration well.

[0134] As can be seen from Figure 15 , the transverse aberration of the longest wavelength and the shortest wavelength is controlled within ±2 μm, which shows that the optical lens 300 can correct chromatic aberration well.

[0135] Embodiment 4

[0136] Please refer to Figure 16 , which is a structural schematic diagram of the optical lens 400 provided in Embodiment 4 of the present application. Compared with Embodiment 1, the main difference is that the image side surface S14 of the seventh lens L7 is concave at the near optical axis; the image side surface S16 of the eighth lens L8 is convex; and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0137] The related parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0138] Table 4-1

[0139]

[0140] The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0141] Table 4-2

[0142]

[0143] In this embodiment, the astigmatism curve, F-Tan (Theta) distortion curve, axial 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.

[0144] from Figure 17 As can be seen, the astigmatism of the meridional and sagittal image planes is controlled within ±0.1mm, indicating that the optical lens 400 can effectively correct astigmatism.

[0145] from Figure 18 As can be seen, the distortion value is controlled within ±1%, indicating that the optical lens 400 can correct distortion well.

[0146] from Figure 19 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens 400 can effectively correct axial aberration.

[0147] from Figure 20 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens 400 can correct chromatic aberration well.

[0148] 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, 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.

[0149] Table 5

[0150]

[0151] In summary, the optical lens provided by the present invention has at least the following advantages:

[0152] (1) Through specific surface shape setting and reasonable power distribution, a large field of view angle is achieved, and a large range of shooting range can be realized; at the same time, a large aperture value is achieved, and high-definition imaging can be realized even in a dark environment.

[0153] (2) The lens has a large target surface, can match a large target surface imaging chip to realize high-definition imaging, and the increase of the target surface can make the pixel distribution more sparse, effectively reduce the noise even in a dark environment, the dynamic range will be wider, and more imaging details can be retained in the dark part, so that clearer shooting effect can be presented; at the same time, the overall aberration of the optical lens can be reasonably corrected, so that the optical lens has small distortion and high definition, and the imaging quality of the optical lens is improved.

[0154] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0155] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the present application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. An optical lens comprising eight lenses, characterized in that, It successively includes from the object side to the imaging surface along the optical axis: A first lens with positive optical power, whose object side is convex and whose image side is concave; A second lens with positive optical power, whose object side is convex and whose image side is concave; A third lens with negative optical power, whose object side is concave and whose image side is concave; A fourth lens with positive optical power, whose object side is convex and whose image side is convex; A fifth lens with negative optical power, whose object side is concave; whose image side is convex; A sixth lens with positive optical power, whose object side is concave and whose image side is convex; A seventh lens with positive optical power, whose object side is convex near the optical axis; An eighth lens with negative optical power, whose object side is concave; Wherein, the true image height IH corresponding to the maximum field angle of the optical lens and the F - number Fno of the optical lens satisfy: 8mm < IH / Fno < 9mm; The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.5 < f1 / f < 1.

6.

2. The optical lens according to claim 1, characterized in that, The combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: - 0.5 < f1234 / f5678 < - 0.

3.

3. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 0.16 < f1 / f2 < 0.

2.

4. The optical lens according to claim 1, characterized in that, The overall length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.3 < TTL / f < 1.

38.

5. 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: 8 < f2 / f < 10.

6. 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: - 2 < f3 / f < - 1.8; the curvature radius R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: - 3.15 < R5 / f < - 2.

95.

7. 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: 1.3 < f4 / f < 1.5; the curvature radius R7 of the object side of the fourth lens and the curvature radius R8 of the image side of the fourth lens satisfy: - 0.5 < R7 / R8 < - 0.

3.

8. 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: - 3 < f5 / f < - 1.5; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.3 < f6 / f < 1.

8.

9. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.5 < f7 / f < 2.8; the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: - 0.85 < f8 / f < - 0.

6.

10. The optical lens according to claim 1, characterized in that, The central thickness CT7 of the seventh lens and the central thickness CT8 of the eighth lens satisfy: 3.2 < CT7 / CT8 < 3.8.

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