Optical lens

Abstract

The present invention provides an optical lens, which has a total of eight lenses. Along the optical axis, from the object side to the imaging surface, it successively includes: a first lens with a negative optical power, whose object side is convex and image side is concave; a second lens with a negative optical power, whose object side is concave and image side is convex; a third lens with a positive optical power, whose image side is convex; a fourth lens with a positive optical power, whose object side is concave and image side is convex; a fifth lens with a positive optical power, whose object side is convex; a sixth lens with a negative optical power; a seventh lens with a positive optical power; an eighth lens with a negative optical power, whose object side is convex and image side is concave. The optical lens provided by the present invention improves the imaging quality of the optical lens, reduces aberration, and improves the imaging quality of the optical lens by reasonable configuration of each lens surface type and reasonable matching of optical powers, enabling the lens to have one or more advantages such as ultra-wide angle, high pixel, and high imaging quality.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and particularly to an optical lens. Background Art

[0002] With the continuous progress and development of existing image processing algorithms and AI technologies, as a special type of optical lens, high-definition wide-angle lenses are widely used in various fields such as action cameras, vehicle-mounted lenses, and smart homes. Therefore, the requirements for high-definition wide-angle lenses are also getting higher and higher.

[0003] However, there are still many deficiencies in existing high-definition wide-angle lens devices. For example, the size of the lens is too long, the volume is large, and the weight is heavy, which is not conducive to carrying; the increase in the field of view angle of the lens leads to difficulties in compensating system aberrations and a decline in imaging quality; the relative aperture of the lens is small, the light transmission performance is poor, and it cannot adapt to a darker environment; and the imaging target surface of the existing lens is small, making it difficult to meet market demands.

[0004] Therefore, it is necessary to develop an optical lens with one or more advantages such as an ultra-wide angle, high imaging quality, and high pixels, so as to better meet the high demands of the market for high-definition wide-angle lenses. Summary of the Invention

[0005] Aiming at the above problems, the purpose of the present invention is to provide an optical lens with one or more advantages such as an ultra-wide angle, high pixels, and high imaging quality.

[0006] The present invention provides an optical lens, which has a total of eight lenses. Along the optical axis from the object side to the imaging surface, it successively includes: a first lens with a negative focal power, whose object side is convex and image side is concave; a second lens with a negative focal power, whose object side is concave and image side is convex; a third lens with a positive focal power, whose image side is convex; a fourth lens with a positive focal power, whose object side is concave and image side is convex; a fifth lens with a positive focal power, whose object side is convex; a sixth lens with a negative focal power; a seventh lens with a positive focal power; an eighth lens with a negative focal power, whose object side is convex and image side is concave.

[0007] Further preferably, a reflection element is provided between the third lens and the fourth lens. The surface of the reflection element facing the object side is the incident surface, and the surface facing the imaging surface is the exit surface.

[0008] Further preferably, the effective focal length f of the optical lens and the overall optical length TTL satisfy: TTL / f < 25.0.

[0009] Further preferably, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle satisfy: TTL / IH < 9.0.

[0010] More preferably, the effective focal length f of the optical lens, the radian θ of the maximum half field angle, and the true image height IH corresponding to the maximum field angle satisfy: 0.75 < (IH / 2) / (f×θ) < 0.9.

[0011] More preferably, the effective focal length f of the optical lens and the back focal length BFL satisfy: BFL / f > 0.8.

[0012] More preferably, the effective focal length f of the optical lens, the maximum field angle FOV, and the true image height IH corresponding to the maximum field angle satisfy: 60.0 < (f×FOV) / IH.

[0013] More preferably, the true image height IHm corresponding to the central field angle of the optical lens and the true image height IH corresponding to the maximum field angle satisfy: 0.52 < IHm / IH.

[0014] More preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: f1 / f < -5.0.

[0015] More preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: f2 / f < -4.0.

[0016] More preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 5.8 < f3 / f.

[0017] More preferably, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 9.0 < f4 / f.

[0018] More preferably, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 3.3 < f5 / f < 4.6.

[0019] More preferably, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -6.5 < f6 / f < -1.2.

[0020] More preferably, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.2 < f7 / f < 5.5.

[0021] More preferably, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: f8 / f < -50.0.

[0022] More preferably, the curvature radius R3 of the object side of the second lens and the curvature radius R4 of the image side satisfy: -0.80 < (R3 - R4) / (R3 + R4) < -0.25.

[0023] More preferably, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface satisfy: 0.7 < (R7 - R8) / (R7 + R8) < 0.85.

[0024] More preferably, the distance CT34 between the third lens and the fourth lens on the optical axis and the effective focal length f of the optical lens satisfy: 1.0 < CT34 / f < 6.0.

[0025] More preferably, the sum ∑CT of the central thicknesses of the lenses from the first lens to the eighth lens and the overall optical length TTL of the optical lens satisfy: 0.35 < ∑CT / TTL < 0.55.

[0026] The optical lens provided by the present invention improves the imaging quality of the optical lens, reduces aberration, and improves the imaging quality of the optical lens through the reasonable configuration of each lens surface type and the reasonable combination of optical powers, enabling the lens to have one or more advantages such as ultra-wide angle, high pixel, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, where:

[0028] Figure 1 is a schematic structural diagram of the optical lens in the example of the present invention.

[0029] Figure 2 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 3 is an MTF curve graph of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 4 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 5 is an MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 6 is a schematic structural diagram of the optical lens in Embodiment 3 of the present invention.

[0034] Figure 7 is an MTF curve graph of the optical lens in Embodiment 3 of the present invention.

[0035] Figure 8 is a schematic structural diagram of the optical lens in Embodiment 4 of the present invention.

[0036] Figure 9 is an MTF curve graph of the optical lens in Embodiment 4 of the present invention.

[0037] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0038] To better understand the present application, more detailed descriptions of various aspects of the present application will be made with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application and do not limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0039] It should be noted that in this specification, the expressions such as first, second, third, etc. are only used to distinguish one feature from another feature and do not represent any limitation on the feature. Therefore, without departing from the teachings of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0040] In the drawings, for the sake of clarity, the thickness, dimensions, and shape of the lens have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are for illustrative purposes only and are not drawn to an exact scale.

[0041] In this document, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object being photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

[0042] It should also be understood that the terms "comprises", "comprising", "has", "including" and / or "including having", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. Further, when an expression such as "at least one of..." appears after the list of listed features, it modifies the entire list of listed features rather than individual elements in the list. Further, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". And the term "exemplary" is intended to refer to an example or illustration.

[0043] Unless otherwise defined, all terms (including technical and scientific terms) used herein shall 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 terms (such as those defined in a common dictionary) should be interpreted as having a meaning 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.

[0044] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will detail this application with reference to the drawings and in combination with the embodiments.

[0045] Example

[0046] Please refer to Figure 1 , which is a schematic structural diagram of the optical lens in the example of the present invention. Figure 1 The difference between (A) and (B) in is that the structure of the prism in (B) is a folding-back structure. The reason for this phenomenon is that in the design process, a folding-back coordinate breakpoint is added at the prism, and the target surface is changed to a reflecting mirror for the folding optical path, so that the optical lens coordinate system behind the prism is changed, resulting in the lens curvature radius R and thickness D / distance L behind the prism being opposite numbers. It should be noted that transforming the optical lens data of the folding-back structure into that of the straight-line structure is for unifying the coordinate system to facilitate the description and calculation of the optical lens, and should not be construed as a limitation on the scope of the present invention patent. Figure 1 The difference between (A) and (C) in is that the prism structure is cancelled in (C). The reason for this phenomenon is that in the design process, considering the assembly requirements of the optical lens, the optical path of the optical lens is designed as a folding-back structure, which is beneficial to the assembly in a narrow space. It should be noted that the purpose of adding the folding-back structure is to improve the compactness of the optical lens and avoid the optical lens being too large and unfavorable for assembly, and should not be construed as a limitation on the scope of the present invention patent.

[0047] The optical lens provided by the embodiment of the present invention has a total of eight lenses, which are, in order from the object side to the imaging surface along the optical axis, 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.

[0048] In some embodiments, the first lens may have a negative optical power, which is beneficial to reducing the inclination angle of the incident light, thereby effectively sharing the large field of view on the object side. The object side surface of the first lens is convex, and the image side surface is concave, which is beneficial to collecting the marginal field of view light into the rear optical lens as much as possible and realizing the collection of large-angle light.

[0049] In some embodiments, the second lens may have a negative optical power, which helps the light to transition smoothly, expands the field of view angle of the optical imaging lens, reduces the difficulty of correcting distortion and chromatic aberration of the rear lens, and improves the image quality of the optical imaging lens. The object side of the second lens is concave, and the image side is convex, which is conducive to receiving the light emitted from the first lens and further diverging the light, making the trend of the light as smooth as possible, and at the same time reducing the field curvature and improving the imaging quality of the optical lens.

[0050] In some embodiments, the third lens may have a positive optical power, which is conducive to improving the light converging ability of the optical lens, and at the same time balancing various aberrations generated by the optical lens, and improving the imaging quality of the optical lens. The image side of the third lens is convex, and the marginal field light is deflected towards the optical axis after passing through the image side of the third lens, which is conducive to reducing the rear aperture of the optical lens.

[0051] In some embodiments, the fourth lens may have a positive optical power, which is conducive to improving the light converging ability of the optical lens, and at the same time can balance various aberrations of the optical lens, and improve the imaging quality of the optical lens. The object side of the fourth lens is concave, and the image side is convex, which can turn and converge the light, share the converging effect of the third lens on the light, is conducive to the light entering the fifth lens more smoothly, reducing the aperture of the rear lens group, and at the same time reducing the sensitivity of the optical lens.

[0052] In some embodiments, the fifth lens may have a positive optical power, which is conducive to improving the light converging ability of the optical lens, and at the same time can balance various aberrations of the optical lens, and improve the imaging quality of the optical lens. The object side of the fifth lens is convex, which can further converge the light emitted from the fourth lens, reduce the aperture of the rear lens, and converge the light so that it reaches the imaging surface, which is conducive to compressing the total length of the optical lens.

[0053] In some embodiments, the sixth lens may have a negative optical power, which is conducive to diverging the light converged by the fourth lens and the fifth lens so that it can reach a higher imaging position. The sixth lens may have a convex object side and a concave image side or a concave object side and a convex image side.

[0054] In some embodiments, the seventh lens may have a positive optical power, which is conducive to further converging the light, and at the same time, when paired with the sixth lens having a negative optical power, can play a role in correcting chromatic aberration. The seventh lens may have a convex object side and a concave image side or both the object side and the image side are convex or a concave object side and a convex image side.

[0055] In some embodiments, the eighth lens may have a negative optical power, which is conducive to diverging the incident light, causing the peripheral light and the central light to turn upwards and reach a higher imaging position. The object side of the eighth lens is convex, and the image side is concave, which can diverge the central light so that the light can reach a higher imaging position. At the same time, it converges the light in the peripheral field of view, which can reduce the incident angle of the light entering the chip and contribute to improving the relative illumination of the optical lens.

[0056] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the fifth lens and the sixth lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the image. In addition, when the diaphragm is located between the fifth lens and the sixth lens, the diaphragm can reasonably distribute the functions of the first lens to the eighth lens. For example, the first lens, the second lens, and the fifth lens can be used to receive light to a greater extent and reduce the generation of various aberrations, and the sixth lens to the eighth lens can be used to correct aberrations, which is beneficial to balancing the structure of the entire optical system. In addition, when the diaphragm is located between the fifth lens and the sixth lens, it is convenient to correct the diaphragm aberration.

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

[0058] In some embodiments, in order to reduce the size of the optical lens, a reflecting element with no optical power for light path folding may be provided between the third lens and the fourth lens, and the reflecting element is a prism. The surface of the prism facing the object side is the incident surface, and the surface facing the imaging surface is the exit surface, and both the incident surface and the exit surface are flat surfaces. The prism can be a right-angle prism. The light from the object side direction enters the prism from the incident surface, is reflected by the reflecting surface, and then exits from the exit surface. By setting the prism to bend the light path, the thickness of the lens can be effectively shortened.

[0059] In some embodiments, the effective focal length f of the optical lens and the overall optical length TTL satisfy: TTL / f < 25.0. Satisfying the above range indicates that the optical length of the optical lens can be effectively limited, which is beneficial to realizing the miniaturization of the optical lens.

[0060] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle satisfy: TTL / IH < 9.0. Satisfying the above range indicates that the overall optical length and the image plane height of the optical lens can be effectively limited, which is beneficial to realizing a short overall optical length and a large image height.

[0061] In some embodiments, the effective focal length f of the optical lens, the radian θ of the maximum half field of view angle, and the true image height IH corresponding to the maximum field of view angle satisfy: 0.75 < (IH / 2) / (f×θ) < 0.9. Meeting the above range indicates that the structure has high design flexibility, can effectively control the distortion range, and meet the requirements of different distortion algorithms.

[0062] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL satisfy: BFL / f > 0.8. Meeting the above range can make the lens have a large back focal length, which is beneficial to the assembly of the module, reduces interference, and improves the production yield.

[0063] In some embodiments, the effective focal length f of the optical lens, the maximum field of view angle FOV, and the true image height IH corresponding to the maximum field of view angle satisfy: 60.0 < (f×FOV) / IH. Meeting the above range is beneficial to meeting the requirements of a large field of view of the optical lens, realizing a large image height and a long focal length at the same time, and is more conducive to achieving small distortion and improving the imaging quality of the optical lens.

[0064] In some embodiments, the true image height IHm corresponding to the central field of view angle of the optical lens and the true image height IH corresponding to the maximum field of view angle satisfy: 0.52 < IHm / IH. Meeting the above range can effectively increase the proportion of the central field of view imaging range in the entire imaging range. Compared with lenses with the same field of view angle, the proportion of the central field of view imaging range in the entire imaging range is larger, and more detailed information can be obtained.

[0065] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: f1 / f < -5.0. Meeting the above range can make the first lens have an appropriate negative optical power, avoid excessive concentration of negative optical power, and at the same time is beneficial to increasing the field of view angle, and is beneficial to collecting as much marginal field of view light as possible into the rear optical lens to achieve large-angle light collection.

[0066] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: f2 / f < -4.0. Meeting the above range can make the second lens have an appropriate negative optical power, increase the field of view angle, and improve the imaging quality of the optical lens.

[0067] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 5.8 < f3 / f. Meeting the above range can make the third lens have an appropriate positive optical power, which is beneficial to improving the light converging ability of the optical lens, and at the same time can balance various aberrations generated by the optical lens and improve the imaging quality of the optical lens.

[0068] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 9.0 < f4 / f. Satisfying the above range can make the fourth lens have an appropriate positive optical power, which is beneficial to improving the light converging ability of the optical lens, and at the same time can balance the aberration of the optical lens and improve the imaging quality of the optical lens.

[0069] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 3.3 < f5 / f < 4.6. Satisfying the above range can make the fifth lens have an appropriate positive optical power, which is beneficial to improving the light converging ability of the optical lens, and at the same time can balance the aberration of the optical lens and improve the imaging quality of the optical lens.

[0070] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -6.5 < f6 / f < -1.2. Satisfying the above range can make the sixth lens have an appropriate negative optical power, which is beneficial to diverging the light converged by the fourth lens and the fifth lens and increasing the image height of the optical lens.

[0071] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.2 < f7 / f < 5.5. Satisfying the above range can make the seventh lens have a suitable positive optical power, which is beneficial to suppressing the angle of the marginal field light exiting.

[0072] In some embodiments, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: f8 / f < -50.0. Satisfying the above range can make the eighth lens have a suitable negative optical power, which is beneficial to diverging the light, making the peripheral light and the central light turn upwards and reach a higher imaging position.

[0073] In some embodiments, the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface satisfy: -0.80 < (R3 - R4) / (R3 + R4) < -0.25. Satisfying the above range can receive the light exiting the first lens and further diverge the light, making the trend of the light as gentle as possible, and at the same time can reduce the field curvature and improve the imaging quality of the optical lens.

[0074] In some embodiments, the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface satisfy: 0.7 < (R7 - R8) / (R7 + R8) < 0.85. Satisfying the above range can turn and converge the light, sharing the converging effect of the third lens on the light, which is beneficial to the light entering the fifth lens more gently, reducing the aperture of the rear lens group, and at the same time reducing the sensitivity of the optical lens.

[0075] In some embodiments, the spacing distance CT34 between the third lens and the fourth lens on the optical axis and the effective focal length f of the optical lens satisfy: 1.0 < CT34 / f < 6.0. Meeting the above range can achieve the folded-back structure of the optical lens and reduce the thickness of the lens.

[0076] In some embodiments, the sum ∑CT of the central thicknesses of the lenses from the first lens to the eighth lens and the overall optical length TTL of the optical lens satisfy: 0.35 < ∑CT / TTL < 0.55. Meeting the above range is beneficial to compressing the overall length and volume of the optical lens and maintaining the miniaturization of the optical lens.

[0077] In some embodiments, the optical lens satisfies the conditional formula: FOV > 190°, 33.0 mm < TTL < 35.5 mm, 1.4 mm < f < 2.0 mm, 4.0 mm < IH < 6.0 mm, where FOV represents the maximum field of view angle of the optical lens, TTL represents the overall optical length of the optical lens, f represents the effective focal length of the optical lens, and IH represents the true image height corresponding to the maximum field of view angle of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention has at least one of the characteristics of ultra-wide angle and large image plane.

[0078] In some embodiments, the sixth lens and the seventh lens can be glued together to form a glued lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing technology difficulty of the optical lens and improving the assembly yield of the optical lens.

[0079] 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 second lens, the third lens, and the eighth lens in the optical lens provided by the present invention can be aspherical lenses, and the first lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens can be spherical lenses.

[0080] In various embodiments of the present invention, when the lens is an aspherical lens, the surface shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0081] ;

[0082] Among them, z is the distance between the surface and the vertex of the surface in the optical axis direction, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the conic coefficient, and B, C, D, E, and F are the surface coefficients of the fourth, sixth, eighth, tenth, and twelfth orders respectively.

[0083] The present invention will be further described below with multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are somewhat different. For specific differences, refer to the parameter tables of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any other changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0084] Embodiment 1

[0085] Please refer to Figure 2 , which shows a schematic structural diagram of the optical lens provided in Embodiment 1 of the present invention. The optical lens sequentially 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 prism, a fourth lens L4, a fifth lens L5, a diaphragm ST, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter G1.

[0086] Among them, the first lens L1 has a negative optical power, its object side S1 is a convex surface, and its image side S2 is a concave surface; the second lens L2 has a negative optical power, its object side S3 is a concave surface, and its image side S4 is a convex surface; the third lens L3 has a positive optical power, its object side S5 is a concave surface, and its image side S6 is a convex surface; the surface of the prism facing the object side is the incident surface, and the surface facing the imaging surface is the exit surface, and both the incident surface and the exit surface are flat surfaces; the fourth lens L4 has a positive optical power, its object side S7 is a concave surface, and its image side S8 is a convex surface; the fifth lens L5 has a positive optical power, its object side S9 is a convex surface, and its image side S10 is a concave surface; the sixth lens L6 has a negative optical power, its object side S11 is a convex surface, and its image side S12 is a concave surface; the seventh lens L7 has a positive optical power, its object side S12 is a convex surface, and its image side S13 is a concave surface, and the sixth lens L6 and the seventh lens L7 form a cemented lens, and its cemented surface is S12; the eighth lens L8 has a negative optical power, its object side S14 is a convex surface, and its image side S15 is a concave surface; the object side S16 and the image side S17 of the filter G1 are both flat surfaces; the imaging surface S18 is a flat surface.

[0087] The first lens L1, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are glass spherical lenses; the second lens L2, the third lens L3, and the eighth lens L8 are glass aspherical lenses.

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

[0089] Table 1-1

[0090]

[0091] The surface profile parameters of the aspherical lens in the optical lens of Embodiment 1 are shown in Table 1-2.

[0092] Table 1-2

[0093]

[0094] In this embodiment, Figure 3 The MTF (Modulation Transfer Function) curve graph of Embodiment 1 is shown, which represents the modulation of the lens imaging at different spatial frequencies in each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF value of this embodiment is above 0.3 in the entire field of view. In the range of 0 to 230 lp / mm, the MTF curve decreases uniformly and smoothly during the process from the central field of view to the edge field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0095] Embodiment 2

[0096] Please refer to Figure 4 , which shows the schematic structural diagram of the optical lens provided in Embodiment 2 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0097] The relevant parameters of each lens in the optical lens of Embodiment 2 are shown in Table 2-1.

[0098] Table 2-1

[0099]

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

[0101] Table 2-2

[0102]

[0103] From Figure 5 it can be seen that the MTF value of this embodiment is above 0.4 in the entire field of view. In the range of 0 to 230 lp / mm, the MTF curve decreases uniformly and smoothly during the process from the central field of view to the edge field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0104] Embodiment 3

[0105] Please refer to Figure 6 , which shows the structural schematic diagram of the optical lens provided in Embodiment 3 of the present invention. Compared with Embodiment 1, the main difference lies in that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0106] The relevant parameters of each lens in the optical lens of Embodiment 3 are shown in Table 3-1.

[0107] Table 3-1

[0108]

[0109] The aspheric lens surface type parameters of the optical lens in Embodiment 3 are shown in Table 3-2.

[0110] Table 3-2

[0111]

[0112] From Figure 7 , it can be seen that the MTF value of this embodiment is above 0.5 within the entire field of view. In the range of 0 - 230 lp / mm, the MTF curve decreases uniformly and smoothly from the center to the edge of the field of view, and it has excellent imaging quality and excellent detail resolution ability in both low-frequency and high-frequency cases.

[0113] Embodiment 4

[0114] Please refer to Figure 8 , which shows the structural schematic diagram of the optical lens provided in Embodiment 4 of the present invention. Compared with Embodiment 1, the main difference lies in that the prism, the curvature radius of each lens surface, the lens thickness and other optical parameters are different.

[0115] The relevant parameters of each lens in the optical lens of Embodiment 4 are shown in Table 4-1.

[0116] Table 4-1

[0117]

[0118] The aspheric lens surface type parameters of the optical lens in Embodiment 4 are shown in Table 4-2.

[0119] Table 4-2

[0120]

[0121] From Figure 9It can be seen that the MTF value of this embodiment is above 0.4 within the entire field of view. In the range of 0 to 230 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0122] Please refer to Table 5 for the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the aperture value Fno, the true image height IH, the entrance pupil diameter EPD, the chief ray angle of incidence CRA at the maximum image height, and the maximum field of view angle FOV, as well as the numerical values corresponding to each conditional expression in each embodiment.

[0123] Table 5

[0124]

[0125] In summary of the above embodiments, the optical lens provided by the present invention improves the imaging quality of the optical lens, reduces aberration, and enhances the imaging quality of the optical lens through the reasonable configuration of each lens surface type and the reasonable combination of optical powers, enabling the lens to have one or more advantages such as ultra-wide angle, high pixel, and high imaging quality.

[0126] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0127] The above-described embodiments merely represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. An optical lens, comprising eight lenses, characterized in that: 依次包括沿光轴从物侧到成像面的部件: 第一透镜,具有负光焦度,其物侧面为凸面,像侧面为凹面; 第二透镜,具有负光焦度,其物侧面为凹面,像侧面为凸面; 第三透镜,具有正光焦度,其像侧面为凸面; 第四透镜,具有正光焦度,其物侧面为凹面,像侧面为凸面; 第五透镜,具有正光焦度,其物侧面为凸面; 第六透镜,具有负光焦度; 第七透镜,具有正光焦度; 第八透镜,具有负光焦度,其物侧面为凸面,像侧面为凹面;第四透镜的焦距f4与光学镜头的有效焦距f满足:9.0 < f4 / f ≤ 13.73;光学镜头的有效焦距f与最大半视场角的弧度θ和最大视场角所对应的真实像高IH满足:0.75 < (IH / 2) / (f×θ) < 0.9。 2. The optical lens according to claim 1, characterized in that: 在第三透镜和第四透镜之间设有反射元件,反射元件朝向物侧的面为入射面,朝向成像面的为出射面。 3. The optical lens according to claim 1, characterized in that: 光学镜头的有效焦距f与光学总长TTL满足:17.40 ≤ TTL / f < 25.0。 4. The optical lens according to claim 1, characterized in that: 光学镜头的光学总长TTL与最大视场角所对应的真实像高IH满足:5.86 ≤ TTL / IH < 9.0。 5. The optical lens according to claim 1, characterized in that: 光学镜头的有效焦距f与最大半视场角的弧度θ和最大视场角所对应的真实像高IH满足:0.77 ≤ (IH / 2) / (f×θ) ≤ 0.87。 6. The optical lens according to claim 1, characterized in that: 光学镜头的有效焦距f、最大视场角FOV与最大视场角所对应的真实像高IH满足:60.0 < (f×FOV) / IH ≤ 74.14。 7. The optical lens according to claim 1, characterized in that: 第一透镜的焦距f1与光学镜头的有效焦距f满足:-7.10 ≤ f1 / f < -5.0。 8. The optical lens according to claim 1, characterized in that: 第二透镜的焦距f2与光学镜头的有效焦距f满足:-7.41 ≤ f2 / f < -4.0。 9. The optical lens according to claim 1, characterized in that: 第四透镜的焦距f4与光学镜头的有效焦距f满足:9.47 ≤ f4 / f ≤ 13.73。 10. The optical lens according to claim 1, characterized in that: 第二透镜的物侧面曲率半径R3与像侧面曲率半径R4满足:-0.80 < (R3 - R4) / (R3 + R4) < -0.25。 11. The optical lens according to claim 1, characterized in that: 第四透镜的物侧面曲率半径R7与像侧面曲率半径R8满足:0.7 < (R7 - R8) / (R7 + R8) < 0.85。 12. The optical lens according to claim 1, characterized in that: 第三透镜和第四透镜在光轴上的间隔距离CT34与光学镜头的有效焦距f满足:1.0 < CT34 / f < 6.0。 13. The optical lens according to claim 1, characterized in that: 第一透镜至第八透镜的各透镜的中心厚度之和∑CT与光学镜头的光学总长TTL满足:0.35 < ∑CT / TTL < 0.55。

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