Optical lens

Abstract

The invention provides an optical lens, which comprises eight lenses from an object side to an imaging surface along an optical axis: a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power, the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a concave surface; the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a convex surface; and the eighth lens has negative focal power. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal power distribution, the lens has one or more advantages of ultra-wide angle, high pixel, large aperture, small distortion, high imaging quality and the like.

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 rapid development of unmanned aerial vehicles, security, automobiles, weather, medical treatment, VR, AR and other fields, the field of view of the lenses carried thereby is also required to be higher and higher. Wide-angle lenses can compress the edge field of view light as much as possible by introducing barrel distortion, thereby realizing an ultra-wide-angle lens with a field of view exceeding 220°. At present, there are still many problems in the ultra-wide-angle lens, such as a small aperture of a common ultra-wide-angle lens, which causes insufficient light entering the lens and unclear imaging, in addition to the problems of great difficulty in aberration correction and oversized head. SUMMARY

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

[0004] The present application provides an optical lens, which comprises eight lenses in sequence along the optical axis from the object side to the imaging surface, i.e. a first lens with negative focal power, whose object side surface is a convex surface and whose image side surface is a concave surface; a second lens with negative focal power, whose image side surface is a concave surface; a third lens with negative focal power, whose object side surface is a convex surface and whose image side surface is a concave surface; a fourth lens with positive focal power, whose image side surface is a convex surface; a fifth lens with positive focal power, whose object side surface is a convex surface and whose image side surface is a convex surface; a sixth lens with negative focal power, whose object side surface is a concave surface and whose image side surface is a concave surface; a seventh lens with positive focal power, whose object side surface is a convex surface and whose image side surface is a convex surface; an eighth lens with negative focal power, whose object side surface is a convex surface near the optical axis and whose image side surface is a concave surface; wherein the combined focal length f123 of the first lens, the second lens and the third lens and the effective focal length f of the optical lens satisfy -1.6 < f123 / f < -1.2.

[0005] Further preferably, the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy -1.1 < f123 / f45678 < -0.9.

[0006] Further preferably, the focal length f3 of the third lens satisfies: -190 < f3 / f < -90; the radius of curvature R5 of the object side surface of the third lens satisfies: 2.7 < R5 / f < 2.9.

[0007] Further preferably, the focal length f4 of the fourth lens satisfies: 2.6 < f4 / f < 2.8; the radius of curvature R8 of the image side surface of the fourth lens satisfies: -1.7 < R8 / f < -1.4.

[0008] Further preferably, the focal length f5 of the fifth lens satisfies: 1.9 < f5 / f < 2; the radius of curvature R9 of the object side surface of the fifth lens satisfies: 0.29 < (R9+R10) / (R9-R10) < 0.45.

[0009] Further preferably, the focal length f6 of the sixth lens satisfies: -2.9 < f6 / f < -2; the radius of curvature R11 of the object side surface of the sixth lens satisfies: -0.5 < (R11+R12) / (R11-R12) < -0.3.

[0010] Further preferably, the focal length f7 of the seventh lens satisfies: 1.5 < f7 / f < 2.3; the radius of curvature R14 of the image side surface of the seventh lens satisfies: -1.5 < R14 / f < -0.9.

[0011] Further preferably, the real image height IH corresponding to the maximum field angle of the optical lens satisfies: 3.6 < IH / f < 3.8.

[0012] Further preferably, the effective focal length f of the optical lens, the aperture value Fno of the optical lens and the total track length TTL of the optical lens satisfy: 0.19 < fxFno / TTL < 0.2.

[0013] Further preferably, the half entrance pupil radius CSD11 of the object side surface of the first lens satisfies: 2.5 < CSD11 / SAG11 < 3.2; the half entrance pupil radius CSD12 of the image side surface of the first lens satisfies: 1.35 < CSD12 / SAG12 < 1.45.

[0014] 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 super wide angle, high pixel, large aperture, small distortion, high imaging quality and the like. BRIEF DESCRIPTION OF DRAWINGS

[0015] 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: Figure 1 FIG. 1 is a structural schematic diagram of an optical lens in Embodiment 1 of the present application.

[0016] Figure 2 FIG. 2 is a field curvature curve diagram of the optical lens in Embodiment 1 of the present application.

[0017] Figure 3 FIG. 3 is an F-Theta distortion curve diagram of the optical lens in Embodiment 1 of the present application.

[0018] Figure 4 FIG. 4 is an axial aberration curve diagram of the optical lens in Embodiment 1 of the present application.

[0019] Figure 5 FIG. 5 is a transverse chromatic aberration curve diagram of the optical lens in Embodiment 1 of the present application.

[0020] Figure 6 FIG. 6 is a structural schematic diagram of an optical lens in Embodiment 2 of the present application.

[0021] Figure 7 FIG. 7 is a field curvature curve diagram of the optical lens in Embodiment 2 of the present application.

[0022] Figure 8 FIG. 8 is an F-Theta distortion curve diagram of the optical lens in Embodiment 2 of the present application.

[0023] Figure 9 FIG. 9 is an axial aberration curve diagram of the optical lens in Embodiment 2 of the present application.

[0024] Figure 10 FIG. 10 is a transverse chromatic aberration curve diagram of the optical lens in Embodiment 2 of the present application.

[0025] Figure 11 FIG. 11 is a structural schematic diagram of an optical lens in Embodiment 3 of the present application.

[0026] Figure 12 FIG. 12 is a field curvature curve diagram of the optical lens in Embodiment 3 of the present application.

[0027] Figure 13 FIG. 13 is an F-Theta distortion curve diagram of the optical lens in Embodiment 3 of the present application.

[0028] Figure 14 Axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0029] Figure 15 Axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0030] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0031] 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.

[0032] It should be noted that the expressions first, second, third, etc. in the present specification are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, 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.

[0033] 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 or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn strictly to scale.

[0034] In this context, 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 image plane is referred to as the image side surface of the lens.

[0035] It should also be understood that the use of the terms "including", "including", "having", "containing", and / or "comprising" when used in this specification, specifies 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 terms such as "at least one of" appear after a list of items, the phrase modifies the entire list of items and does not modify the list of items individually. In addition, when describing embodiments of the present application, the use of "may" indicates that "one or more embodiments of the present application". And the term "exemplary" is intended to refer to an example or illustration.

[0036] 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 the present application belongs. It should also be understood that the terms (such as those defined in a commonly used dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0037] 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 combination with the embodiments.

[0038] The optical lens provided by the embodiments of the present application comprises eight lenses, and the optical lens comprises, along the optical axis from the object side to the imaging surface, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens.

[0039] In some embodiments, the first lens can have a negative focal power, the object side surface of which is convex, and the image side surface of which is concave. The second lens can have a negative focal power, the object side surface of which can be concave or convex, and the image side surface of which is concave. The third lens can have a negative focal power, the object side surface of which is convex, and the image side surface of which is concave. The fourth lens can have a positive focal power, the object side surface of which can be concave or convex, and the image side surface of which is convex. The fifth lens can have a positive focal power, the object side surface of which is convex, and the image side surface of which is convex. The sixth lens can have a negative focal power, the object side surface of which is concave, and the image side surface of which is concave. The seventh lens can have a positive focal power, the object side surface of which is convex, and the image side surface of which is convex. The eighth lens can have a negative focal power, the object side surface of which is convex at the near optical axis, and the image side surface of which is concave.

[0040] In some embodiments, the optical lens can further comprise a diaphragm, which can be located between the fourth lens and the fifth lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging. When the diaphragm is located between the fourth lens and the fifth lens, the correction of the diaphragm aberration is facilitated.

[0041] In some embodiments, the optical lens may further include a filter disposed between the eighth lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0042] In some embodiments, the combined focal length f123 of the first lens, the second lens, and the third lens satisfies the effective focal length f of the optical lens: -1.6 <f123 / f<-1.2。满足上述条件式,将第一透镜至第三透镜组成的前透镜组设计为负光焦度,使光学镜头能接收大角度视场光线,并有利于大角度光线束透过光阑,以满足光学镜头的超广角化,同时也有助于提升边缘视场处于成像面上的亮度,从而提升边缘视场处的成像清晰度。

[0043] In some embodiments, the combined focal length f123 of the first lens, the second lens, and the third lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy: -1.1 <f123 / f45678<-0.9。满足上述条件式,有利于合理控制光阑前后透镜组的焦距比,实现光学镜头的大光圈,大靶面的效果,同时,光线能够充满整个光阑,有利于光学镜头光阑前后的像差平衡。

[0044] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -190 <f3 / f<-90;满足上述条件式,使第三透镜为光学镜头提供负屈折力,从而有利于校正光学镜头的色差以及有利于修正光学镜头的像差,以提升光学镜头的成像解析力,同时还有利于减小光学镜头的偏心敏感度;同时,第三透镜还有利于调整来自第一透镜和第二透镜的光线走势,使边缘光线经过第三透镜继续发散,校正边缘视场像差。

[0045] In some embodiments, the object side curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: 2.7 <R5 / f<2.9。满足上述条件式,这样设置使得第三透镜的物侧侧面的形状为凸面,使得经过第二透镜的光线收缩至第三透镜中,可减小后面透镜的尺寸,有助于光学镜头的小型化,并且第三透镜可有效减少球差与像散产生以提升光学镜头的成像品质。

[0046] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 2.6 < f4 / f < 2.8. By setting the fourth lens to have a large positive refractive power, the light rays from the first three lenses can be converged, the aberration problems caused by the first three negative focal length lenses can be corrected, the aberration of the edge field of view can be effectively improved, and the overall imaging quality of the optical lens can be improved.

[0047] In some embodiments, the image side surface curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -1.7 < R8 / f < -1.4. By controlling the surface shape of the image side surface of the fourth lens, the spherical aberration of the optical lens can be effectively corrected, the influence of the astigmatism on the imaging of the optical lens can be reduced, and the light ray trend can be adjusted to make the optical lens have a large field of view and be ultra-thin.

[0048] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 1.9 < f5 / f < 2. By cooperating with the fourth lens to further limit the light ray trend, the aberration caused by the light ray turning of the front lenses can be corrected, and the imaging quality can be ensured.

[0049] In some embodiments, the object side surface curvature radius R9 of the fifth lens and the image side surface curvature radius R10 of the fifth lens satisfy: 0.29 < (R9+R10) / (R9-R10) < 0.45. By designing the fifth lens to be a double convex surface, the incident angle can be reasonably increased to meet the image height requirement of the optical lens, the sensitivity of the optical lens can be reduced, and the assembly stability can be improved.

[0050] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -2.9 < f6 / f < -2. By reasonably controlling the focal length value of the sixth lens, the large field of view light rays are slowly lifted, the parallel light trend of the light beam is changed to a divergent trend, which is conducive to controlling the back focus of the lens and realizing a large target surface and reducing the chief ray incident angle.

[0051] In some embodiments, the object side surface curvature radius R11 of the sixth lens and the image side surface curvature radius R12 of the sixth lens satisfy: -0.5 < (R11+R12) / (R11-R12) < -0.3. By designing the sixth lens to be a double concave surface, it can be ensured that the sixth lens can better diverge light rays, thereby reducing the risk of ghosting and improving the resolving power of the system.

[0052] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.5 < f7 / f < 2.3. Satisfying the above condition, the positive refractive power strength of the seventh lens provided for the optical lens can effectively constrain the rear end light rays, thereby effectively correcting chromatic aberration, and meanwhile, as the lens at the rear end position of the optical lens, the seventh lens can correct the aberration caused by the decentration of each lens on the object side, that is, the decentration sensitivity of the optical lens can be reduced, the astigmatism caused by the decentration of each lens on the object side can be suppressed, thereby correcting the aberration of the optical lens and improving the imaging resolution.

[0053] In some embodiments, the image side surface curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.5 < R14 / f < -0.9. Satisfying the above condition, the surface shape of the image side surface of the seventh lens is controlled, the spherical aberration of the optical lens is effectively corrected, the influence of astigmatism on the imaging of the optical lens is reduced, and the light ray trend is adjusted, so that the optical lens has a large field of view and is super-thin.

[0054] 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: 3.6 < IH / f < 3.8. Satisfying the above condition, the ratio of the effective focal length to the image height of the optical lens is controlled, the effective focal length is shortened to expand the field of view angle, so that the optical lens can capture a wider object side space, and meanwhile, the optical lens can match a large image chip to improve the imaging quality of the optical lens.

[0055] In some embodiments, the effective focal length f of the optical lens, the aperture value Fno of the optical lens, and the total optical length TTL of the optical lens satisfy: 0.19 < fxFno / TTL < 0.2. Satisfying the above condition, the optical lens satisfies the characteristics of short focal length and large aperture, has sufficient light amount, has a large wide-angle field of view to capture more scene information, and has a flexible depth of field to strengthen the picture layering, thereby facilitating clearer shooting images, and meanwhile, the optical length is limited, so that the optical lens also satisfies miniaturization.

[0056] In some embodiments, the object side surface half light entrance radius CSD11 of the first lens and the object side surface half light entrance vertex height SAG11 of the first lens satisfy: 2.5 < CSD11 / SAG11 < 3.2; and the image side surface half light entrance radius CSD12 of the first lens and the image side surface half light entrance vertex height SAG12 of the first lens satisfy: 1.35 < CSD12 / SAG12 < 1.45. Satisfying the above condition, the large-angle light rays can be incident to the optical lens, the image height and the imaging quality of the optical lens are improved, the surface shapes of the object side surface and the image side surface of the first lens are not too curved, the processing difficulty and the ghosting risk of the first lens are reduced, and the problem of uneven coating caused by too much bending of the first lens is avoided.

[0057] In some embodiments, the interval CT23 of the second lens and the third lens on the optical axis, the interval CR34 of the third lens and the fourth lens on the optical axis, and the total optical length TTL of the optical lens satisfy: 0.075≤(CT23+CT34) / TTL≤0.09. By satisfying the above condition, the air gap of the second lens and the third lens, the air gap of the third lens and the fourth lens on the optical axis, and the total optical length of the optical lens are reasonably configured, so as to shorten the total optical length of the optical lens, achieve miniaturization design, and facilitate the reasonable transition of light between the second lens, the third lens and the fourth lens, thereby improving the relative illumination of the optical lens.

[0058] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.6<f2 / f<-3.1. By satisfying the above condition, the second lens has a negative focal length, which ensures that the light beam entering the second lens is divergent, the large field of view light is slowly raised, which is beneficial to achieve a large aperture and a large target surface, and is beneficial to the smooth light trend and the reduction of aberration, thereby improving the imaging quality of the optical lens.

[0059] In some embodiments, the focal length f3 of the third lens and the central thickness CT3 of the third lens satisfy: -255<f3 / CT3<-170. By satisfying the above condition, the effective focal length and the thickness of the third lens are reasonably configured, so that the light entering the optical lens is more gentle, the sensitivity of the optical lens is reduced, the aberration of the optical lens is corrected, and the imaging quality of the optical lens is improved.

[0060] In some embodiments, the maximum field of view angle FOV of the optical lens and the chief ray angle of incidence CRA at the maximum image height of the optical lens satisfy: 5.6<FOV / CRA<6. By satisfying the above condition, the incident light of different field angles of the optical lens can be incident on the image sensor at a suitable angle, thereby improving the photosensitive performance of the image sensor and the imaging quality of the optical lens.

[0061] In some embodiments, the object side light half aperture radius CSD31 of the third lens and the object side light half aperture radius sag31 of the third lens satisfy: 3.4<CSD31 / SAG31<5.1. By satisfying the above condition, the edge region surface of the object side of the third lens is adjusted, the ghost reflection energy is reduced, the field curvature is optimized, and the imaging quality of the optical lens is improved.

[0062] In some embodiments, the image-side half-field aperture radius CSD22 of the second lens and the image-side half-field aperture sag SAG22 of the second lens satisfy: 2.3 < CSD22 / SAG22 < 3. By adjusting the surface shape of the edge region of the image side of the second lens to satisfy the above condition, the edge field of view light is diverged, and at the same time, the off-axis aberration of the edge field of view of the optical lens is corrected, and the imaging quality of the optical lens is improved.

[0063] In some embodiments, the central thickness CT4 of the fourth lens and the image-side half-field aperture sag SAG42 of the fourth lens satisfy: -2.5 < CT4 / SAG42 < -1.9. By satisfying the above condition, the central thickness of the fourth lens is not too large or the image side is too curved to increase the difficulty of lens manufacturing while satisfying the refractive power, thereby reducing the production cost.

[0064] In some embodiments, the optical lens satisfies the following condition: 1.55 mm < f < 1.6 mm; 205° < FOV < 220°; 1 mm < EPDI < 1.1 mm; 12 mm < TTL < 12.5 mm; 1.5 ≤ Fno ≤ 1.55; 5.7 mm < IH < 6.1 mm. By satisfying the above condition, the optical lens has at least one or more advantages of short focal length, ultra-large field of view, large entrance pupil diameter, short total length, large aperture, large image surface, low distortion, and low sensitivity.

[0065] In some embodiments, the eight lenses in the optical lens can be made of plastic or made of glass-plastic hybrid material. Preferably, the optical lens of the present application adopts an eight-lens structure of glass-plastic hybrid material, which can improve the thermal stability. Specifically, the first lens and the fifth lens can be made of glass, and the second lens, the third lens, the fourth lens, the sixth lens, the seventh lens, and the eighth lens can be made of plastic. The glass-plastic hybrid structure can effectively reduce the cost, correct the aberration, reduce the volume, and provide a higher cost-effective optical lens product.

[0066] 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 be made of 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 lens miniaturization. More specifically, the first lens and the fifth lens of the optical lens of the present application can be made of a spherical lens, and the second lens, the third lens, the fourth lens, the sixth lens, the seventh lens, and the eighth lens can be made of an aspherical lens.

[0067] In various embodiments of the present application, when the lens is an aspherical lens, the shape of each aspherical surface of the optical lens satisfies the following equation: ; 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 of the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the coefficient of the quadratic curved surface, B, C, D, E, F, G, H are the coefficients of the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, sixteenth-order curved surface respectively.

[0068] The application will be further described in the following embodiments. In each embodiment, 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 the preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments only, any change, replacement, combination or simplification made without departing from the innovative points of the application should be regarded as equivalent replacement mode, and all are included in the protection scope of the application.

[0069] Embodiment 1 Please refer to Figure 1 , which is a structural schematic diagram of the optical lens 100 provided in the embodiment 1 of the application. The optical lens 100 comprises, along the optical axis from the object side to the imaging surface S19, a first lens L1, a second lens L2, a third lens L3, a stop ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8 and a filter G1.

[0070] The first lens L1 has negative focal power, the object side S1 thereof is a convex surface, and the image side S2 thereof is a concave surface; The second lens L2 has negative focal power, the object side S3 thereof is a convex surface, and the image side S4 thereof is a concave surface; The third lens L3 has negative focal power, the object side S5 thereof is a convex surface, and the image side S6 thereof is a concave surface; The fourth lens L4 has positive focal power, the object side S7 thereof is a convex surface, and the image side S8 thereof is a convex surface; The fifth lens L5 has positive focal power, the object side S9 thereof is a convex surface, and the image side S10 thereof is a convex surface; The sixth lens L6 has negative focal power, the object side S11 thereof is a concave surface, and the image side S12 thereof is a concave surface; The seventh lens L7 has positive focal power, the object side S13 thereof is a convex surface, and the image side S14 thereof is a convex surface; The eighth lens L8 has negative focal power, the object side S15 thereof is a convex surface at the near optical axis, and the image side S16 thereof is a concave surface; The object side S17 and the image side S18 of the filter G1 are both flat surfaces; The imaging surface S19 is a flat surface.

[0071] The first lens L1 and the fifth lens L5 are glass spherical lenses; the second lens L2, the third lens L3, the fourth lens L4, the sixth lens L6, the seventh lens L7 and the eighth lens L8 are plastic aspherical lenses.

[0072] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0073] Table 1-1 The surface parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0074] Table 1-2 In this embodiment, the field curvature curve, the F-Theta distortion curve, the axial aberration curve and the transverse aberration curve of the optical lens 100 are shown in FIGS. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5

[0075] Figure 2 The field curvature curve of the optical lens 100 in Embodiment 1 is shown in FIG. 1-1, which represents the curvature of the light rays on the meridional image surface and the sagittal 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 field curvature of the meridional image surface and the sagittal image surface is controlled within-0.05mm~0.1mm, which shows that the optical lens 100 can well correct the field curvature.

[0076] Figure 3 The F-Theta distortion curve of the optical lens 100 in Embodiment 1 is shown in FIG. 1-2, which represents the F-Theta distortion of the light rays at 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 F-Theta distortion of the optical lens is controlled within 0~10%, which shows that the optical lens 100 can well correct the distortion.

[0077] Figure 4 The axial aberration curve of the optical lens 100 in Embodiment 1 is shown in FIG. 1-3, 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-0.02mm~0.04mm, which shows that the optical lens 100 can well correct the axial aberration.

[0078] Figure 5 ​The axial chromatic aberration curve of the optical lens 100 in Embodiment 1 is shown, which represents the chromatic aberration of each wavelength at different image heights on the imaging plane relative to the central wavelength (0.555 μm), the horizontal axis represents the axial 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 axial chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -4 μm ~ 6 μm, which shows that the optical lens 100 can correct chromatic aberration well.

[0079] Embodiment 2 Please refer to Figure 6 , which is a structural schematic diagram of the optical lens 200 provided in Embodiment 2 of the present application. Compared with Embodiment 1, the main difference is that the object side S3 of the second lens L2 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0080] The related parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0081] Table 2-1 The surface type parameters of the aspherical lens of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0082] Table 2-2 In this embodiment, the field curvature curve, the F-Theta distortion curve, the axial aberration curve, and the axial chromatic aberration curve of the optical lens 200 are shown in Figure 7 , Figure 8 , Figure 9 , Figure 10 respectively.

[0083] As can be seen from Figure 7 , the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.1 mm ~ 0.05 mm, which shows that the optical lens 200 can correct the field curvature well.

[0084] As can be seen from Figure 8 , the F-Theta distortion of the optical lens is controlled within 0 ~ 10%, which shows that the optical lens 200 can correct the distortion well.

[0085] As can be seen from Figure 9 , the offset of the axial aberration is controlled within -0.02 mm ~ 0.02 mm, which shows that the optical lens 200 can correct the axial aberration well.

[0086] As can be seen from Figure 10It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -4μm~6μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0087] Example 3 See also Figure 11 , shown is a schematic structural diagram of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main differences between this embodiment and Example 1 are: the object-side surface S7 of the fourth lens L4 is concave; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0088] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0089] Table 3-1 The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0090] Table 3-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens 300 are shown as follows: Figure 12 、 Figure 13 、 Figure 14 、 Figure 15 shown.

[0091] from Figure 12 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.1mm~0.05mm, indicating that the optical lens 300 can correct the field curvature well.

[0092] from Figure 13 It can be seen that the F-Theta distortion of the optical lens is controlled within 0~10%, indicating that the optical lens 300 can correct the distortion well.

[0093] from Figure 14 It can be seen that the offset of the axial aberration is controlled within -0.02mm~0.04mm, indicating that the optical lens 300 can correct the axial aberration well.

[0094] from Figure 15 It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -4μm~5μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0095] Please refer to Table 4 for the optical characteristics of the above-mentioned embodiments, including the effective focal length f, the total track length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the chief ray angle of incidence CRA at the maximum image height, the maximum field of view angle FOV of the optical lens, and the numerical value corresponding to each conditional expression in the embodiments.

[0096] Table 4 In summary of the above embodiments, the optical lens provided by the present application adopts eight pieces of glass-plastic hybrid structure, and through specific surface shape matching and reasonable refractive power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved, so that the lens has one or more advantages of ultra-wide angle, high pixel, large aperture, small distortion, high imaging quality, etc.

[0097] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection 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.

[0098] The above-mentioned embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be noted that, for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application 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 a negative optical power, whose object side is convex and whose image side is concave; A second lens with a negative optical power, whose image side is concave; A third lens with a negative optical power, whose object side is convex and whose image side is concave; A fourth lens with a positive optical power, whose image side is convex; A fifth lens with a positive optical power, whose object side is convex and whose image side is convex; A sixth lens with a negative optical power, whose object side is concave and whose image side is concave; A seventh lens with a positive optical power, whose object side is convex and whose image side is convex; An eighth lens with a negative optical power, whose object side is convex near the optical axis and whose image side is concave; Wherein, the combined focal length f123 of the first lens, the second lens and the third lens and the effective focal length f of the optical lens satisfy: -1.6 < f123 / f < -1.

2.

2. The optical lens according to claim 1, wherein: The combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -1.1 < f123 / f45678 < -0.

9.

3. The optical lens according to claim 1, wherein: The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -190 < f3 / f < -90; the curvature radius R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: 2.7 < R5 / f < 2.

9.

4. The optical lens according to claim 1, wherein: The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 2.6 < f4 / f < 2.8; the curvature radius R8 of the image side of the fourth lens and the effective focal length f of the optical lens satisfy: -1.7 < R8 / f < -I.

4.

5. The optical lens according to claim 1, wherein: The focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 1.9 < f5 / f < 2; the curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side of the fifth lens satisfy: 0.29 < (R9 + R10) / (R9 - R10) < 0.

45.

6. The optical lens according to claim 1, wherein: The focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -2.9 < f6 / f < -2; the curvature radius R11 of the object side of the sixth lens and the curvature radius R12 of the image side of the sixth lens satisfy: -0.5 < (R11 + R12) / (R11 - R12) < -0.

3.

7. The optical lens according to claim 1, wherein: The focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.5 < f7 / f < 2.3; the curvature radius R14 of the image side of the seventh lens and the effective focal length f of the optical lens satisfy: -1.5 < R14 / f < -0.

9.

8. The optical lens according to claim 1, wherein: 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: 3.6 < IH / f < 3.

8.

9. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens, the aperture value Fno of the optical lens and the overall optical length TTL of the optical lens satisfy: 0.19 < f × Fno / TTL < 0.

2.

10. The optical lens according to claim 1, wherein: The clear semi-diameter CSD11 of the object side surface of the first lens and the sag SAG11 of the clear semi-diameter of the object side surface of the first lens satisfy: 2.5 < CSD11 / SAG11 < 3.2; the clear semi-diameter CSD12 of the image side surface of the first lens and the sag SAG12 of the clear semi-diameter of the image side surface of the first lens satisfy: 1.35 < CSD12 / SAG12 < 1.45.

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