Optical lens

Abstract

The invention provides an optical lens, which consists of eight lenses, and sequentially comprises 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 from an object side to an imaging surface, the second lens has negative focal power; the third lens has positive focal power; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a concave surface; the fifth lens has positive focal power, and the object side surface of the fifth lens is a convex surface; the sixth lens has negative focal power, and the image side surface of the sixth lens is a concave surface; the seventh lens has positive focal power, and the object side surface of the seventh lens is a convex surface; and the object side surface of the eighth lens is a concave surface, and the image side surface of the eighth lens is a concave surface near the optical axis. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, the imaging quality of the optical lens can be improved, and the lens has one or more advantages of large field angle, large aperture, 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] The law enforcement instrument is mainly used for digital recording of the scene in the law enforcement process, such as video shooting, photographing, audio recording, etc., so as to provide effective scene image data afterwards. In the process of on-site law enforcement, law enforcement personnel need to record a larger range and clear image, however, the lens of the law enforcement instrument on the market either records unclear images or has too small a field of view and cannot record too many pictures.

[0003] Therefore, how to make the lens of the law enforcement instrument meet high imaging quality is a problem to be solved at present. SUMMARY

[0004] In view of the above problems, the purpose of the present application is to provide an optical lens, which has the advantages of excellent imaging quality.

[0005] The technical scheme adopted by the present application is:

[0006] An optical lens composed of eight lenses, sequentially including, along the optical axis from the object side to the imaging surface:

[0007] A first lens with negative focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;

[0008] A second lens with negative focal power;

[0009] A third lens with positive focal power;

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

[0011] A fifth lens with positive focal power, the object side surface of which is a convex surface;

[0012] A sixth lens with negative focal power, the image side surface of which is a concave surface;

[0013] A seventh lens with positive focal power, the object side surface of which is a convex surface;

[0014] An eighth lens with negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface near the optical axis;

[0015] Wherein, the object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: 0.1<(R7-R8) / (R7+R8)<0.7, and the object side surface curvature radius R15 of the eighth lens and the image side surface curvature radius R16 of the eighth lens satisfy: -0.5<(R15+R16) / (R15-R16)<0.9.

[0016] Further preferably, the total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.5 < TTL / f < 10; the total track length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.4 < TTL / IH < 4.6.

[0017] Further preferably, the maximum field angle FOV of the optical lens and the aperture value FNO of the optical lens satisfy: 55° < FOV / FNO < 90°; the real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4 < IH / EPD < 6.

[0018] 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: 1.8 < IH / f < 3; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.6 < BFL / f < 1.6.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -3.4 < f1 / f < -1.3, the effective focal length f of the optical lens and the radius of curvature R1 of the object side surface of the first lens satisfy: 3.6 < R1 / f < 88, the effective focal length f of the optical lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 1 < R2 / f < 2.4.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -75 < f2 / f < -1.3; the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.3 < f3 / f < 5.3.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -13 < f4 / f < -2.1; the effective focal length f of the optical lens and the radius of curvature R7 of the object side surface of the fourth lens satisfy: 1.9 < R7 / f < 4.2; the effective focal length f of the optical lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 0.7 < R8 / f < 2.3.

[0022] Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.7 < f6 / f < -1; the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 0.8 < f7 / f < 1.5.

[0023] It is further preferred that the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -70 < f8 / f < -3.3; the object side curvature radius R15 of the eighth lens and the effective focal length f of the optical lens satisfy: -44 < R15 / f < -3.3; and the image side curvature radius R16 of the eighth lens and the effective focal length f of the optical lens satisfy: 2.4 < R16 / f < 25.

[0024] It is further preferred that the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 1.3 < f45678 / f < 7.9; and the object side half light entrance radius d1 of the first lens and the image side half light entrance radius d16 of the eighth lens satisfy: 1.5 < d1 / d16 < 2.8.

[0025] 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 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 such as a large field of view, a large aperture, and high imaging quality. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:

[0027] Figure 1 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

[0028] Figure 2 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

[0029] Figure 3 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

[0030] Figure 4 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

[0031] Figure 5 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

[0032] Figure 6 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

[0033] Figure 7 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

[0034] FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.Figure 8 F-Tan(Theta) Distortion curve of the optical lens in Embodiment 2 of the present application.

[0035] Figure 9 Axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0036] Figure 10 Decentration curve of the optical lens in Embodiment 2 of the present application.

[0037] Figure 11 MTF curve of the optical lens in Embodiment 2 of the present application.

[0038] Figure 12 Relative illuminance curve of the optical lens in Embodiment 2 of the present application.

[0039] Figure 13 Structure diagram of the optical lens in Embodiment 3 of the present application.

[0040] Figure 14 F-Tan(Theta) Distortion curve of the optical lens in Embodiment 3 of the present application.

[0041] Figure 15 Axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0042] Figure 16 Decentration curve of the optical lens in Embodiment 3 of the present application.

[0043] Figure 17 MTF curve of the optical lens in Embodiment 3 of the present application.

[0044] Figure 18 Relative illuminance curve of the optical lens in Embodiment 3 of the present application.

[0045] Figure 19 Structure diagram of the optical lens in Embodiment 4 of the present application.

[0046] Figure 20 F-Tan(Theta) Distortion curve of the optical lens in Embodiment 4 of the present application.

[0047] Figure 21 Axial aberration curve of the optical lens in Embodiment 4 of the present application.

[0048] Figure 22 Decentration curve of the optical lens in Embodiment 4 of the present application.

[0049] Figure 23 MTF curve of the optical lens in Embodiment 4 of the present application.

[0050] Figure 24 Relative illuminance curve of the optical lens in Embodiment 4 of the present application.

[0051] Figure 25 Structural schematic diagram of the optical lens in Embodiment 5 of the present application.

[0052] Figure 26 F-Tan(Theta) distortion curve of the optical lens in Embodiment 5 of the present application.

[0053] Figure 27 Axial aberration curve of the optical lens in Embodiment 5 of the present application.

[0054] Figure 28 Decentration curve of the optical lens in Embodiment 5 of the present application.

[0055] Figure 29 MTF curve of the optical lens in Embodiment 5 of the present application.

[0056] Figure 30 Relative illuminance curve of the optical lens in Embodiment 5 of the present application.

[0057] Figure 31 Structural schematic diagram of the optical lens in Embodiment 6 of the present application.

[0058] Figure 32 F-Tan(Theta) distortion curve of the optical lens in Embodiment 6 of the present application.

[0059] Figure 33 Axial aberration curve of the optical lens in Embodiment 6 of the present application.

[0060] Figure 34 Decentration curve of the optical lens in Embodiment 6 of the present application.

[0061] Figure 35 MTF curve of the optical lens in Embodiment 6 of the present application.

[0062] Figure 36 Relative illuminance curve of the optical lens in Embodiment 6 of the present application.

[0063] Figure 37 Structural schematic diagram of the optical lens in Embodiment 7 of the present application.

[0064] Figure 38 F-Tan(Theta) distortion curve of the optical lens in Embodiment 7 of the present application.

[0065] Figure 39 Axial aberration curve of the optical lens in Embodiment 7 of the present application.

[0066] Figure 40 Figure 7 is a plot of the relative illumination curve for the optical lens of Example 7 of the present application.

[0067] Figure 41 Figure 8 is a plot of the MTF curve for the optical lens of Example 8 of the present application.

[0068] Figure 42 Figure 9 is a plot of the relative illumination curve for the optical lens of Example 8 of the present application.

[0069] Figure 43 Figure 10 is a schematic diagram of the optical lens of Example 9 of the present application.

[0070] Figure 44 Figure 11 is a plot of the F-Tan(Theta) distortion curve for the optical lens of Example 9 of the present application.

[0071] Figure 45 Figure 12 is a plot of the axial aberration curve for the optical lens of Example 9 of the present application.

[0072] Figure 46 Figure 13 is a plot of the sagittal chromatic aberration curve for the optical lens of Example 9 of the present application.

[0073] Figure 47 Figure 14 is a plot of the MTF curve for the optical lens of Example 9 of the present application.

[0074] Figure 48 Figure 15 is a plot of the relative illumination curve for the optical lens of Example 9 of the present application.

[0075] The following detailed description of the application will further illustrate the application with reference to the above figures. DETAILED DESCRIPTION

[0076] For a better understanding of the present application, various aspects of the present application will be discussed in more detail below with reference to the above figures. It should be appreciated that these details are merely illustrative of the present application and are not intended to limit the scope of the present application in any manner. Throughout this specification, like reference numerals can refer to like elements throughout the description and the figures. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0077] It should be noted that the terms first, second, third, etc. are merely used to distinguish one feature from another and do not imply any limitation on the features. Thus, a first lens discussed below could also be termed a second lens or a third lens without departing from the teachings of the present application.

[0078] In the drawings, the thickness, size, and shape of the lenses have been exaggerated slightly 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 to scale.

[0079] In this document, the paraxial region refers to a region near the optical axis. If the 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 the 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 surface is referred to as the image side surface of the lens.

[0080] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, mean that something is present, but do not exclude the presence of one or more additional features, elements, components, and / or combinations thereof. In addition, when describing the embodiments of the present application, the use of "may" means that one or more embodiments of the present application. Also, the word "exemplary" is intended to mean an example or an illustration.

[0081] 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.

[0082] 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 drawings and in conjunction with the embodiments.

[0083] The optical lens provided by the embodiment of the present application is composed of eight lenses, which are sequentially arranged along the optical axis from the object side to the imaging surface 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.

[0084] 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 can be concave or convex. The third 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 can be concave or convex. The fourth 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 fifth lens can have a positive focal power, the object side surface of which is convex, and the image side surface of which can be concave or convex. The sixth 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 seventh lens can have a positive focal power, the object side surface of which is convex, and the image side surface of which can be concave or convex. The eighth lens can have a negative focal power, the object side surface of which is concave, and the image side surface of which is concave at the near optical axis.

[0085] In some embodiments, the optical lens can further comprise a diaphragm, which can be located between the third lens and the fourth lens. It can be understood that the diaphragm can be used to limit the amount of light to change the brightness of the imaging.

[0086] In some embodiments, the optical lens can further comprise a filter, which can be arranged between the eighth lens and the imaging surface. The filter is used to filter out interference light to prevent the interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0087] In some embodiments, the sixth lens and the seventh lens can be glued to form a glued lens, which can effectively correct the chromatic aberration of the optical lens, reduce the sensitivity of the optical lens to decentration, balance the aberration of the optical lens, and improve the imaging quality of the optical lens. In addition, the glued lens can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0088] In some embodiments, the object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: 0.1<(R7-R8) / (R7+R8)<0.7, and the object side surface curvature radius R15 of the eighth lens and the image side surface curvature radius R16 of the eighth lens satisfy: -0.5<(R15+R16) / (R15-R16)<0.9. Satisfying the above range can correct the aberration of the optical lens, ensure the smoothness of the light passing through the fourth and eighth lenses, reduce the tolerance sensitivity of the optical lens, and facilitate the smooth entry of light. More specifically, 0.15<(R7-R8) / (R7+R8)<0.7; -0.49<(R15+R16) / (R15-R16)<0.85.

[0089] In some embodiments, the optical total length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.5 < TTL / f < 10; the optical total 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: 2.4 < TTL / IH < 4.6. Satisfying the above ranges, by reasonably controlling the total length, focal length and image height of the optical lens, the balance between the total length and volume of the optical lens is achieved, and the structural stability of the optical lens is improved. More specifically, 5.91 < TTL / f < 9.28, 2.6 < TTL / IH < 4.23.

[0090] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value FNO of the optical lens satisfy: 55° < FOV / FNO < 90°; the real image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4 < IH / EPD < 6. Satisfying the above ranges, the large field of view angle and large aperture characteristics of the optical lens are achieved, the light quantity is increased, and the relative luminance is improved. More specifically, 60.6° < FOV / FNO < 88.1°, 4.21 < IH / EPD < 5.54.

[0091] 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: 1.8 < IH / f < 3; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.6 < BFL / f < 1.6. Satisfying the above ranges, the image height, focal length and back focal length of the optical lens can be reasonably controlled. Under the condition that the focal length is fixed, the characteristics of large target surface and long back focal length of the optical lens are improved. The characteristics of large target surface help to improve the imaging quality of the optical lens, and the characteristics of long back focal length can meet the arrangement requirements of the rear-end chip and reduce the assembly and processing difficulty. More specifically, 2 < IH / f < 2.77, 0.66 < BFL / f < 1.44.

[0092] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -3.4 < f1 / f < -1.3, the effective focal length f of the optical lens and the radius of curvature R1 of the object side surface of the first lens satisfy: 3.6 < R1 / f < 88, the effective focal length f of the optical lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 1 < R2 / f < 2.4; the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 0.5 < (R1-R2) / (R1+R2) < 1. Satisfying the above ranges makes the first lens have a suitable negative focal length and a reasonable surface shape, which helps to collect as much light as possible into the optical lens at a large field angle to obtain more image information, and controls the trend of the edge light at a large angle to improve the imaging quality of the optical lens. More specifically, -3.15 < f1 / f < -1.47, 3.97 < R1 / f < 80.04, 1.04 < R2 / f < 2.22; 0.53 < (R1-R2) / (R1+R2) < 0.98.

[0093] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -75 < f2 / f < -1.3. Satisfying the above range makes the second lens have a suitable negative focal length, which helps to make the divergent light enter the lenses in the rear end smoothly, and makes the light trend smooth. More specifically, -68.87 < f2 / f < -1.47.

[0094] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.3 < f3 / f < 5.3. Satisfying the above range makes the third lens have a suitable positive focal length, which helps to converge light, and the lens shape is gentle, which is beneficial to reduce the volume and reduce the cost. More specifically, 1.47 < f3 / f < 4.86.

[0095] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -13 < f4 / f < -2.1; the effective focal length f of the optical lens and the radius of curvature R7 of the object side surface of the fourth lens satisfy: 1.9 < R7 / f < 4.2; the effective focal length f of the optical lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 0.7 < R8 / f < 2.3. Satisfying the above ranges helps to collect light emitted by the lenses in the front end by reasonably controlling the focal length ratio and the surface shape of the fourth lens, and makes the collected light smoothly enter the lenses in the rear, and is beneficial to improve the resolving power of the optical lens. More specifically, -12.58 < f4 / f < -2.35; 2.06 < R7 / f < 3.83; 0.81 < R8 / f < 2.09.

[0096] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.7 < f6 / f < -1; the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 0.8 < f7 / f < 1.5. By reasonably setting the focal lengths of the sixth lens and the seventh lens to better correct the chromatic aberration of the system, the overall imaging quality is improved. More specifically, -1.57 < f6 / f < -1.17; 0.9 < f7 / f < 1.34.

[0097] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -70 < f8 / f < -3.3; the object side curvature radius R15 of the eighth lens and the effective focal length f of the optical lens satisfy: -44 < R15 / f < -3.3; the image side curvature radius R16 of the eighth lens and the effective focal length f of the optical lens satisfy: 2.4 < R16 / f < 25. By reasonably controlling the focal length ratio of the eighth lens, the light ray to the image plane is smoothly controlled, the characteristics of a large target surface are obtained, and the optical lens is ensured to have high resolution capability on the basis of eliminating ghost images, thereby improving the imaging quality of the optical lens. More specifically, -9.16 < f8 / f < -3.65; -40.09 < R15 / f < -3.63; 2.64 < R16 / f < 22.73.

[0098] In some embodiments, the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 1.3 < f45678 / f < 7.9. By reasonably setting the positive refractive power of the stop rear lens group, the distortion and astigmatism generated by the front end lens of the optical lens are balanced, and the imaging quality of the optical lens is improved. More specifically, 1.39 < f45678 / f < 7.19.

[0099] In some embodiments, the object side half aperture diameter d1 of the first lens and the image side half aperture diameter d16 of the eighth lens satisfy: 1.5 < d1 / d16 < 2.8. By controlling the aperture ratio of the front and rear lenses, the light ray trend is limited within a reasonable range, and the imaging surface illuminance is uniform. More specifically, 1.61 < d1 / d16 < 2.57.

[0100] In some embodiments, the effective focal length f of the optical lens, the maximum field of view FOV of the optical lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 55° < f x FOV / IH < 80°. By reasonably limiting the relationship among the focal length, the field of view and the image height of the optical lens, the balance between the large field of view and the large target surface imaging of the optical lens is achieved. More specifically, 58.15° < f x FOV / IH < 77.51°.

[0101] In some embodiments, the first lens satisfies: 0 < d1 / (IH / 2) / tan(FOV / 2) < 1.2, where d1 is a half of the entrance pupil diameter of the object side of the first lens, IH is a real image height corresponding to the maximum field angle of the optical lens, and FOV is the maximum field angle of the optical lens. When the above range is satisfied, the optical lens has a large field angle and a large image height while the front end has a small diameter. More specifically, 0.03 < d1 / (IH / 2) / tan(FOV / 2) < 1.12.

[0102] In some embodiments, the optical lens satisfies: 1.2 < f5 / f < 3.3, where f is the effective focal length of the optical lens, and f5 is the focal length of the fifth lens; and 0.9 < R9 / f < 5.7, where R9 is the radius of curvature of the object side of the fifth lens, and f is the effective focal length of the optical lens. When the above ranges are satisfied, the focal length ratio of the fifth lens and the surface shape of the fifth lens are controlled, which helps to smooth the light path of the front end lens, corrects the aberration generated by the front end lens, and improves the imaging quality. More specifically, 1.3 < f5 / f < 3.08; and 0.96 < R9 / f < 5.23.

[0103] In some embodiments, the optical lens satisfies: 0.7 < R12 / f < 1.3, where R12 is the radius of curvature of the image side of the sixth lens, and f is the effective focal length of the optical lens; and 0.7 < R13 / f < 1.3, where R13 is the radius of curvature of the object side of the seventh lens, and f is the effective focal length of the optical lens. When the above conditions are satisfied, the image side of the sixth lens and the object side of the seventh lens are cemented, which effectively corrects the chromatic aberration of the optical lens and reduces the sensitivity of the optical lens to decentration. More specifically, 0.81 < R12 / f < 1.2; and 0.81 < R13 / f < 1.2.

[0104] In some embodiments, the optical lens satisfies the condition formula: 1.8mm < f < 2.8mm, 0.9mm < EPD < 1.4mm, 15mm < TTL < 21mm, 1.8 < FNO < 2.3, 13° < CRA < 25°, 1.3mm < BFL < 4mm, 120° < FOV < 180°, 3.8mm < IH < 6mm; wherein f represents an effective focal length of the optical lens, EPD represents an entrance pupil diameter of the optical lens, TTL represents an optical total length of the optical lens, FNO represents an aperture value of the optical lens, CRA represents a chief ray angle of incidence at a maximum image height of the optical lens, BFL represents a back focal length of the optical lens, FOV represents a maximum field of view angle of the optical lens, and IH represents a real image height corresponding to the maximum field of view angle of the optical lens. The above condition is satisfied, indicating that the optical lens provided by the embodiment of the present application at least has the characteristics of large field of view angle, large aperture, high imaging quality, and the like. More specifically, 1.94mm < f < 2.62mm, 0.92mm < EPD < 1.31mm, 15.13mm < TTL < 20.1mm, 1.9 < FNO < 2.2, 13.86° < CRA < 24.21°, 1.4mm < BFL < 3.66mm, 127.26° < FOV < 176.1°, 3.91mm < IH < 5.81mm.

[0105] 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 itself. In the optical lens provided by the present application, the first lens, the second lens, the fifth lens, the sixth lens and the seventh lens are glass lenses, the fourth lens is a glass lens or a plastic lens, and the third lens and the eighth lens are plastic lenses.

[0106] 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 spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the third lens, the fourth lens, the fifth lens and the eighth lens of the present application are aspherical lenses, and the first lens, the second lens, the sixth lens and the seventh lens are spherical lenses.

[0107] 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:

[0108]

[0109] 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 surface, B, C, D, E, F, G, H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, sixteenth-order coefficients of the curved surface, respectively.

[0110] 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, and any change, replacement, combination or simplification made without departing from the innovative points of the application should be regarded as equivalent replacement, and all are included in the protection scope of the application.

[0111] Embodiment 1

[0112] 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 includes, along the optical axis from the object side to the imaging surface, 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.

[0113] The first lens L1 has a negative focal power, the object side surface S1 is a convex surface, and the image side surface S2 is a concave surface.

[0114] The second lens L2 has a negative focal power, the object side surface S3 is a convex surface, and the image side surface S4 is a concave surface.

[0115] The third lens L3 has a positive focal power, the object side surface S5 is a convex surface, and the image side surface S6 is a concave surface.

[0116] The fourth lens L4 has a negative focal power, the object side surface S7 is a convex surface, and the image side surface S8 is a concave surface.

[0117] The fifth lens L5 has a positive focal power, the object side surface S9 is a convex surface, and the image side surface S10 is a convex surface.

[0118] The sixth lens L6 has a negative focal power, the object side surface S11 is a concave surface, and the image side surface is a concave surface.

[0119] The seventh lens L7 has a positive focal power, the object side surface is a convex surface, and the image side surface S13 is a convex surface.

[0120] The sixth lens L6 and the seventh lens L7 form a cemented lens group with a positive focal power, that is, the cemented surface of the image side surface of the sixth lens L6 and the object side surface of the seventh lens L7 is S13.

[0121] The eighth lens L8 has negative refractive power, the object side surface S14 is a concave surface, and the image side surface S15 is a concave surface at the near optical axis.

[0122] The object side surface S16 and the image side surface S17 of the filter G1 are both planar surfaces.

[0123] The imaging surface S18 is a planar surface.

[0124] The first lens L1, the second lens L2, the sixth lens L6 and the seventh lens L7 are all glass spherical lenses, the fifth lens L5 is a glass aspherical lens, and the third lens L3, the fourth lens L4 and the eighth lens L8 are all plastic aspherical lenses.

[0125] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0126] Table 1-1

[0127]

[0128]

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

[0130] Table 1-2

[0131] Face number K B C D E F G H S5 -4.38E+00 5.69E-03 -9.05E-05 6.78E-04 -6.25E-04 6.74E-04 -2.49E-04 3.58E-05 S6 1.76E+01 3.96E-03 -9.50E-04 -8.39E-03 7.80E-03 -2.75E-03 3.79E-04 5.82E-06 S7 1.04E+01 1.16E-02 -8.52E-03 1.77E-03 -1.78E-03 1.95E-04 3.77E-04 -1.30E-04 S8 -1.94E+01 -6.03E-03 2.28E-05 1.40E-04 1.73E-04 -1.24E-04 -2.58E-05 6.24E-06 S9 -9.35E+00 -9.10E-03 2.78E-03 4.03E-04 -7.38E-05 -2.13E-05 0.00E+00 0.00E+00 S10 -1.79E+02 -5.36E-04 -4.50E-04 3.02E-04 1.84E-04 -3.14E-05 0.00E+00 0.00E+00 S14 -3.40E+01 -3.15E-02 -1.59E-04 4.25E-04 -1.12E-04 -9.66E-06 6.90E-06 -5.38E-07 S15 1.29E+01 -2.47E-02 1.79E-03 7.28E-05 -2.29E-05 -6.05E-06 2.13E-06 -1.59E-07

[0132] Figure 2 The F-Tan(Theta) distortion curve of the optical lens 100 in this embodiment is shown, 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 change of the distortion value is relatively stable with the increase of the field angle, which shows that the optical lens 100 can correct the distortion well.

[0133] Figure 3 The axial aberration curve of the optical lens 100 in this embodiment is shown, 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-0.04mm-0.06mm, which shows that the optical lens 100 can correct the axial aberration well.

[0134] Figure 4A curve diagram of the axial chromatic aberration of the optical lens 100 in the embodiment is shown, 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 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 diagram, the axial chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1 μm-5 μm, which indicates that the optical lens 100 can better correct chromatic aberration.

[0135] Figure 5 A modulation transfer function (MTF) curve diagram of the optical lens 100 in the embodiment is shown, which represents the imaging modulation degree of the lens at different spatial frequencies under each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the diagram, the MTF value of the embodiment is above 0.38 within the full field of view, and the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, which has better imaging quality and better detail resolution capability in the case of low frequency and high frequency.

[0136] Figure 6 A relative luminance curve of the optical lens 100 in the embodiment is shown, which represents the relative luminance value of different field angles on the imaging surface, the horizontal axis represents the half field angle (unit: °), and the vertical axis represents the relative luminance (unit: %). As can be seen from the diagram, the relative luminance value of the optical lens is still greater than 70% at the maximum half field angle, which indicates that the optical lens has better relative luminance.

[0137] Embodiment 2

[0138] Please refer to Figure 7 , which is a structural schematic diagram of the optical lens 200 provided in the embodiment 2 of the application. Compared with the embodiment 1, the main difference is that the image side S6 of the third lens L3 is a convex surface, the object side S11 of the sixth lens L6 is a convex surface, and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0139] The related parameters of each lens in the optical lens 200 in the embodiment 2 are shown in Table 2-1.

[0140] Table 2-1

[0141]

[0142] The surface type parameters of the aspheric lens of the optical lens 200 in the embodiment 2 are shown in Table 2-2.

[0143] Table 2-2

[0144]

[0145]

[0146] In the present embodiment, the F-Tan(Theta) distortion curve, axial aberration curve, sagittal chromatic aberration curve, MTF curve and relative illumination diagram of the optical lens 200 are shown in FIGS. 1-4, respectively. Figures 8 to 12

[0147] As can be seen from FIG. 1, the change of the distortion value is relatively stable as the field angle increases, indicating that the optical lens 200 can correct distortion well. Figure 8 As can be seen from FIG. 2, the shift of the axial aberration is controlled within -0.06mm-0.04mm, indicating that the optical lens 200 can correct axial aberration well.

[0148] Figure 9 As can be seen from FIG. 3, the sagittal chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1um-5um, indicating that the optical lens 200 can correct chromatic aberration well.

[0149] As can be seen from FIG. 4, the MTF value of the present embodiment is above 0.4 in the full field of view, and the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in low frequency and high frequency cases. Figure 10 As can be seen from FIG. 4, the relative illumination value of the optical lens is still greater than 85% at the maximum half field angle, indicating that the optical lens 200 has good relative illumination.

[0150] Figure 11 Example 3

[0151] Please refer to FIG. 5, which is a structural schematic diagram of an optical lens 300 provided in the embodiment 3 of the present application. Compared with the embodiment 1, the main difference is that: the image side S6 of the third lens L3 is a convex surface; the image side S10 of the fifth lens L5 is a concave surface; the object side S11 of the sixth lens L6 is a convex surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different. Figure 12 The related parameters of each lens in the optical lens 300 in the embodiment 3 are shown in Table 3-1.

[0152] Table 3-1

[0153] Figure 13

[0154]

[0155]

[0156]

[0157]

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

[0159] Table 3-2

[0160] Face number K B C D E F G H S5 2.63E-01 4.54E-03 6.82E-04 5.71E-04 -6.82E-04 5.25E-04 -1.97E-04 3.08E-05 S6 -1.55E+01 -1.50E-05 7.98E-03 -9.61E-03 6.62E-03 -2.53E-03 4.52E-04 -1.83E-05 S7 8.25E+00 1.90E-02 -1.23E-02 3.58E-03 -2.55E-03 -1.80E-04 4.87E-04 -1.46E-04 S8 -1.22E+01 -1.30E-02 2.25E-03 2.34E-04 -5.10E-04 -2.54E-04 -4.22E-05 4.04E-05 S9 -6.84E+00 -6.57E-03 -2.35E-04 -1.43E-05 6.65E-05 6.05E-05 0.00E+00 0.00E+00 S10 7.12E+02 -5.40E-03 -8.32E-04 1.93E-04 6.94E-05 7.10E-05 0.00E+00 0.00E+00 S14 1.53E+01 -2.42E-02 1.60E-03 -1.08E-03 -1.99E-04 8.06E-05 3.26E-05 -1.14E-05 S15 5.40E+01 -1.34E-02 -1.78E-04 -5.85E-05 -4.51E-06 1.11E-06 2.09E-07 -4.69E-08

[0161] In this embodiment, the F-Tan (Theta) distortion curve, axial aberration curve, transverse chromatic aberration curve, MTF curve, and relative illumination diagram of the optical lens 300 are respectively as follows: Figures 14 to 18 As shown.

[0162] from Figure 14 As can be seen, the distortion value changes relatively smoothly as the field of view increases, indicating that the optical lens 300 can correct distortion well.

[0163] from Figure 15 As can be seen, the axial aberration offset is controlled within -0.1mm to 0.02mm, indicating that the optical lens 300 can correct axial aberration well.

[0164] from Figure 16 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 4μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0165] from Figure 17 As can be seen, the MTF value of this embodiment is above 0.35 throughout the entire field of view. The MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution in both low and high frequency conditions.

[0166] from Figure 18 As can be seen, the relative illumination value of the optical lens is still greater than 85% at the maximum half field of view, indicating that the optical lens has good relative illumination.

[0167] Example 4

[0168] Please see Figure 19 The diagram shows a schematic of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main differences between this embodiment and Embodiment 1 are: the image-side surface S6 of the third lens L3 is convex; the image-side surface S10 of the fifth lens L5 is concave; the object-side surface S11 of the sixth lens L6 is convex; the image-side surface S13 of the seventh lens L7 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

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

[0170] Table 4-1

[0171]

[0172] The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0173] Table 4-2

[0174]

[0175]

[0176] In this embodiment, the F-Tan (Theta) distortion curve, axial aberration curve, transverse chromatic aberration curve, MTF curve, and relative illumination diagram of the optical lens 400 are respectively as follows: Figures 20 to 24 As shown.

[0177] from Figure 20 As can be seen, the distortion value changes relatively smoothly as the field of view increases, indicating that the optical lens 400 can correct distortion well.

[0178] from Figure 21 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.08mm, indicating that the optical lens 400 can correct axial aberration well.

[0179] from Figure 22 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -4μm to 3μm, indicating that the optical lens 400 can correct chromatic aberration well.

[0180] from Figure 23 As can be seen, the MTF value of this embodiment is above 0.45 throughout the entire field of view. The MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution in both low and high frequency conditions.

[0181] from Figure 24 As can be seen, the relative illumination value of the optical lens is still greater than 78% at the maximum half field of view, indicating that the optical lens has good relative illumination.

[0182] Example 5

[0183] Please see Figure 25 The figure shows a schematic diagram of the structure of the optical lens 500 provided in Embodiment 5 of the present invention. The main differences between this embodiment and Embodiment 1 are: the object-side surface S3 of the second lens L2 is concave; the image-side surface S6 of the third lens L3 is convex; the image-side surface S10 of the fifth lens L5 is concave; the object-side surface S11 of the sixth lens L6 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

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

[0185] Table 5-1

[0186]

[0187]

[0188] The surface profile parameters of the aspherical lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0189] Table 5-2

[0190] Face number K B C D E F G H S5 4.00E+00 2.45E-03 -1.12E-03 1.74E-03 -7.05E-04 2.86E-04 -8.53E-05 1.45E-05 S6 -1.24E+01 -6.67E-03 8.36E-03 -5.67E-03 4.34E-03 -1.99E-03 4.65E-04 -3.45E-05 S7 1.37E+01 1.53E-02 -1.28E-02 4.36E-03 -7.29E-04 -3.45E-04 1.75E-04 -1.99E-05 S8 -1.15E+01 -1.56E-02 2.08E-04 -1.50E-04 3.02E-05 1.17E-05 -8.87E-08 1.01E-06 S9 -1.20E+01 -3.26E-03 1.84E-03 -6.68E-05 -1.13E-06 2.29E-06 0.00E+00 0.00E+00 S10 1.02E+02 -5.14E-03 1.83E-03 -1.79E-04 -8.82E-05 -4.50E-06 0.00E+00 0.00E+00 S14 8.95E+01 -1.69E-02 -8.11E-04 -1.90E-04 -2.47E-05 1.90E-06 -5.04E-07 -7.86E-07 S15 2.08E+01 -1.46E-02 1.54E-04 1.69E-05 -2.33E-06 -4.15E-07 6.23E-08 -2.91E-09

[0191] In this embodiment, the F-Tan (Theta) distortion curve, axial aberration curve, transverse chromatic aberration curve, MTF curve, and relative illumination diagram of the optical lens 500 are respectively as follows: Figures 26 to 30 As shown.

[0192] from Figure 26 As can be seen, the distortion value changes relatively smoothly as the field of view increases, indicating that the optical lens 500 can correct distortion well.

[0193] from Figure 27 As can be seen, the axial aberration offset is controlled within -0.03mm to 0.02mm, indicating that the optical lens 500 can correct axial aberration well.

[0194] from Figure 28 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 3μm, indicating that the optical lens 500 can correct chromatic aberration well.

[0195] from Figure 29 As can be seen, the MTF value of this embodiment is above 0.55 throughout the entire field of view. The MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution in both low and high frequency conditions.

[0196] from Figure 30 As can be seen, the relative illumination value of the optical lens is still greater than 78% at the maximum half field of view, indicating that the optical lens has good relative illumination.

[0197] Example 6

[0198] Please see Figure 31, which is a structural schematic diagram of the optical lens 600 provided in Embodiment 6 of the present application. Compared with Embodiment 1, the main difference is that the sixth lens L6 and the seventh lens L7 form a cemented lens group with negative focal power; the object side S3 of the second lens L2 is a concave surface; the image side S6 of the third lens L3 is a convex surface; the image side S13 of the seventh lens L7 is a concave surface; and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0199] The related parameters of each lens in the optical lens 600 in Embodiment 6 are shown in Table 6-1.

[0200] Table 6-1

[0201]

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

[0203] Table 6-2

[0204]

[0205]

[0206] In this embodiment, the F-Tan(Theta) distortion curve, the axial aberration curve, the transverse chromatic aberration curve, the MTF curve, and the relative luminance diagram of the optical lens 600 are shown in Figures 32 to 36 , respectively.

[0207] As can be seen from Figure 32 , the change of the distortion value is relatively stable with the increase of the field angle, which indicates that the optical lens 600 can better correct the distortion.

[0208] As can be seen from Figure 33 , the shift amount of the axial aberration is controlled within-0.2mm-0.05mm, which indicates that the optical lens 600 can better correct the axial aberration.

[0209] As can be seen from Figure 34 , the transverse chromatic aberration of the longest wavelength and the shortest wavelength is controlled within-1μm-3μm, which indicates that the optical lens 600 can better correct the chromatic aberration.

[0210] As can be seen from Figure 35 , the MTF value of this embodiment is above 0.35 in the full field of view, and the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, which has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0211] As can be seen from Figure 36It can be seen from the figure that the relative illumination value of the optical lens is still greater than 80% at the maximum half field angle, which indicates that the optical lens has a good relative illumination.

[0212] Embodiment 7

[0213] Please refer to Figure 37 , which is a structural schematic diagram of the optical lens 700 provided in Embodiment 7 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 object side S5 of the third lens L3 is a concave surface; the image side S6 of the third lens L3 is a convex surface; the object side S11 of the sixth lens L6 is a convex surface; and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0214] The related parameters of each lens in the optical lens 700 in Embodiment 7 are shown in Table 7-1.

[0215] Table 7-1

[0216]

[0217]

[0218] The surface type parameters of the aspherical lens of the optical lens 700 in Embodiment 7 are shown in Table 7-2.

[0219] Table 7-2

[0220] Face number K B C D E F G H S5 3.68E+02 -1.96E-03 -3.74E-04 7.58E-04 -7.72E-04 3.55E-04 -8.40E-05 8.11E-06 S6 -8.56E+00 -1.40E-02 7.99E-03 -8.59E-03 5.46E-03 -1.77E-03 2.15E-04 3.79E-06 S7 8.23E+00 1.33E-02 -1.28E-02 4.44E-03 -6.47E-04 -3.61E-04 1.65E-04 -1.76E-05 S8 -6.31E+00 -4.16E-03 1.60E-03 -3.52E-04 -4.30E-05 1.12E-05 1.50E-06 1.82E-07 S9 -1.43E+01 -5.75E-03 8.19E-04 5.23E-05 1.60E-05 -2.18E-06 0.00E+00 0.00E+00 S10 -8.45E-01 -2.61E-03 -4.67E-04 7.15E-05 -2.94E-05 5.37E-06 0.00E+00 0.00E+00 S14 2.73E+02 -9.81E-03 -1.16E-05 4.64E-06 -1.14E-06 -8.48E-07 2.68E-08 4.18E-09 S15 -1.25E+00 -1.16E-02 5.42E-05 6.61E-06 -2.73E-06 -2.63E-07 9.16E-08 -5.53E-09

[0221] In this embodiment, the F-Tan(Theta) distortion curve, the axial aberration curve, the transverse aberration curve, the MTF curve, and the relative illumination diagram of the optical lens 700 are shown in Figures 38 to 42 , respectively.

[0222] It can be seen from Figure 38 that the change of the distortion value is relatively stable with the increase of the field angle, which indicates that the optical lens 700 can correct the distortion well.

[0223] It can be seen from Figure 39 that the shift amount of the axial aberration is controlled within-0.02mm-0.02mm, which indicates that the optical lens 700 can correct the axial aberration well.

[0224] It can be seen from Figure 40 that the transverse aberration of the longest wavelength and the shortest wavelength is controlled within-2μm-3μm, which indicates that the optical lens 700 can correct the chromatic aberration well.

[0225] It can be seen from Figure 41It can be seen from the figure that the MTF value of the optical lens in the embodiment is above 0.4 in the full field of view, and the MTF curve uniformly and smoothly decreases from the central field of view to the edge field of view, and the optical lens has good imaging quality and good detail resolution capability in the case of low frequency and high frequency.

[0226] From Figure 42 It can be seen from the figure that the relative illumination value of the optical lens is still greater than 80% at the maximum half field of view, which indicates that the optical lens has good relative illumination.

[0227] Embodiment 8

[0228] Please refer to Figure 43 , which is a structural schematic diagram of the optical lens 800 provided in the embodiment 8 of the present application. Compared with the embodiment 1, the main difference is that the object side S3 of the second lens L2 is a concave surface, the image side S4 of the second lens L2 is a convex surface, the object side S5 of the third lens L3 is a concave surface, the image side S6 of the third lens L3 is a convex surface, the object side S11 of the sixth lens L6 is a convex surface, and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0229] The related parameters of each lens in the optical lens 800 in the embodiment 8 are shown in Table 8-1.

[0230] Table 8-1

[0231]

[0232] The surface type parameters of the aspheric lens of the optical lens 800 in the embodiment 8 are shown in Table 8-2.

[0233] Table 8-2

[0234]

[0235]

[0236] In the embodiment, the F-Tan(Theta) distortion curve, the axial aberration curve, the off-axis chromatic aberration curve, the MTF curve and the relative illumination diagram of the optical lens 800 are respectively shown in Figures 44 to 48 .

[0237] From Figure 44 It can be seen that the change of the distortion value is relatively stable with the increase of the field of view, which indicates that the optical lens 800 can better correct the distortion.

[0238] From Figure 45 It can be seen that the shift amount of the axial aberration is controlled within-0.02mm-0.02mm, which indicates that the optical lens 800 can better correct the axial aberration.

[0239] from Figure 46 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 4μm, indicating that the optical lens 800 can correct chromatic aberration well.

[0240] from Figure 47 As can be seen, the MTF value of this embodiment is above 0.55 throughout the entire field of view. The MTF curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution in both low and high frequency conditions.

[0241] from Figure 48 As can be seen, the relative illumination value of the optical lens is still greater than 90% at the maximum half field of view, indicating that the optical lens has good relative illumination.

[0242] Please refer to Table 9 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.

[0243] Table 9

[0244]

[0245]

[0246] In summary, the optical lens provided by the present invention employs eight lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as a large field of view, a large aperture, and high imaging quality.

[0247] 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.

[0248] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope 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, several modifications and improvements can be made, which are 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 consisting of eight pieces of lenses, characterized in that, In order from the object side to the imaging surface along the optical axis, successively comprises: a first lens with negative refractive power, the object side surface of which is convex, and the image side surface of which is concave; a second lens with negative refractive power; a third lens with positive refractive power; a fourth lens with negative refractive power, the object side surface of which is convex, and the image side surface of which is concave; a fifth lens with positive refractive power, the object side surface of which is convex; a sixth lens with negative refractive power, the image side surface of which is concave; a seventh lens with positive refractive power, the object side surface of which is convex; an eighth lens with negative refractive power, the object side surface of which is concave, and the image side surface of which is concave at the near optical axis; wherein the object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: 0.1<(R7-R8) / (R7+R8)<0.7, and the object side surface curvature radius R15 of the eighth lens and the image side surface curvature radius R16 of the eighth lens satisfy: -0.5<(R15+R16) / (R15-R16)<0.

9.

2. The optical lens of claim 1, wherein, The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.5<TTL / f<10; 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: 2.4<TTL / IH<4.

6.

3. The optical lens of claim 1, wherein, The maximum field angle FOV of the optical lens and the aperture value FNO of the optical lens satisfy: 55°<FOV / FNO<90°; the real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4<IH / EPD<6.

4. The optical lens of claim 1, wherein, 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: 1.8<IH / f<3; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.6<BFL / f<1.

6.

5. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -3.4<f1 / f<-1.3; the effective focal length f of the optical lens and the object side surface curvature radius R1 of the first lens satisfy: 3.6<R1 / f<88; the effective focal length f of the optical lens and the image side surface curvature radius R2 of the first lens satisfy: 1<R2 / f<2.

4.

6. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -75<f2 / f<-1.3; the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.3<f3 / f<5.

3.

7. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -13<f4 / f<-2.1; the effective focal length f of the optical lens and the object side surface curvature radius R7 of the fourth lens satisfy: 1.9<R7 / f<4.2; the effective focal length f of the optical lens and the image side surface curvature radius R8 of the fourth lens satisfy: 0.7<R8 / f<2.

3.

8. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f6 of the sixth lens satisfy: -1.7 < f6 / f < -1; an effective focal length f of the optical lens and a focal length f7 of the seventh lens satisfy: 0.8 < f7 / f < 1.

5.

9. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f8 of the eighth lens satisfy: -70 < f8 / f < -3.3; a radius of curvature R15 of an object side surface of the eighth lens and an effective focal length f of the optical lens satisfy: -44 < R15 / f < -3.3; a radius of curvature R16 of an image side surface of the eighth lens and an effective focal length f of the optical lens satisfy: 2.4 < R16 / f < 25.

10. The optical lens of claim 1, wherein, A combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and an effective focal length f of the optical lens satisfy: 1.3 < f45678 / f < 7.9; a half radius of light passing d1 of an object side surface of the first lens and a half radius of light passing d16 of an image side surface of the eighth lens satisfy: 1.5 < d1 / d16 < 2.8.

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