Optical lens

Abstract

The present invention provides an optical lens, which sequentially includes, from the object side to the imaging surface along the optical axis: a first lens with a negative optical power, whose object side is convex and whose image side is concave; a second lens with a negative optical power, whose object side is concave near the optical axis and whose image side is concave; a third lens with a positive optical power, whose object side is convex near the optical axis; a fourth lens with a positive optical power, whose object side is concave and whose image side is convex; a fifth lens with a positive optical power, whose object side is convex and whose image side is convex; a sixth lens with a negative optical power, whose image side is concave; a seventh lens with a positive optical power, whose object side is convex and whose image side is convex; an eighth lens with a negative optical power, whose object side is convex near the optical axis and whose image side is concave. The optical lens of the present invention can improve the imaging quality of the optical lens and has the advantages of excellent 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 rapid development of fields such as drones, security, automobiles, meteorology, medical treatment, VR, and AR, higher and higher requirements are put forward for the field of view angle of the lenses carried by them. The wide-angle lens introduces barrel distortion, compresses the marginal field light as much as possible, and then realizes an ultra-wide-angle lens with a field of view angle exceeding 200°. At present, there are still many problems with ultra-wide-angle lenses. For example, common ultra-wide-angle lenses have a small aperture, which will cause insufficient light input of the lens and unclear imaging. In addition, there are problems such as large difficulty in aberration correction and large distortion. Summary of the Invention

[0003] Aiming at the above problems, the purpose of the present invention is to provide an optical lens, which has the advantage of excellent imaging quality.

[0004] The present invention provides an optical lens, which has a total of eight lenses, and sequentially includes from the object side to the imaging surface along the optical axis:

[0005] A first lens with a negative focal power, the object side surface of which is convex and the image side surface of which is concave;

[0006] A second lens with a negative focal power, the object side surface of which is concave near the optical axis and the image side surface of which is concave;

[0007] A third lens with a positive focal power, the object side surface of which is convex near the optical axis;

[0008] A fourth lens with a positive focal power, the object side surface of which is concave and the image side surface of which is convex;

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

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

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

[0012] An eighth lens with a negative focal power, the object side surface of which is convex near the optical axis and the image side surface of which is concave;

[0013] Wherein, the total optical length TTL of the optical lens and the aperture value Fno of the optical lens satisfy: 7.8mm < TTL / Fno < 8.5mm.

[0014] Further preferably, the true image height ih corresponding to the maximum half field of view angle of the optical lens, the effective focal length f of the optical lens, and the radian value θ of the maximum half field of view angle of the optical lens satisfy: 0.96 / rad < ih / (f×θ) < 1.04 / rad.

[0015] Further preferably, the true image height ih corresponding to the maximum half field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 2.6 < ih / EPD < 2.9.

[0016] Further preferably, the effective focal length f of the optical lens and the radian value θ of the maximum half field of view angle of the optical lens satisfy: 0.8mm / rad < f / θ < 0.87mm / rad.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -3.5 < f2 / f < -2.4.

[0018] Further preferably, the effective focal length f of the optical lens and the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens satisfy: 3.2 < f1234 / f < 9.5; the effective focal length f of the optical lens and the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy: 2.2 < f5678 / f < 2.8.

[0019] Further preferably, the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy: 1.2 < f1234 / f5678 < 4.2.

[0020] Further preferably, the curvature radius R15 of the object side surface of the eighth lens and the curvature radius R16 of the image side surface of the eighth lens satisfy: 2.2 < (R15 + R16) / (R15 - R16) < 3.4.

[0021] Further preferably, the clear aperture semi-diameter CSD11 at the object side end of the first lens and the clear aperture semi-diameter CSD81 at the object side end of the eighth lens satisfy: 2.3 < CSD11 / CSD81 < 3.

[0022] Further preferably, the sagitta corresponding to the maximum clear aperture semi-diameter at the image side end of the second lens and the central thickness CT2 of the second lens along the optical axis satisfy: 0.8 < SAGX22 / CT2 < 1.3.

[0023] Compared with the prior art, the optical lens provided by the present invention adopts eight lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and endow the lens with one or more advantages such as ultra-wide angle, large aperture, high pixel, and large target surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of embodiments in conjunction with the accompanying drawings, wherein:

[0025] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0026] Figure 2 is the field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 3 is the F-Theta distortion curve diagram of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 4 is the axial aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 5 is the lateral chromatic aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 6 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 7 is the field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 8 is the F-Theta distortion curve diagram of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 9 is the axial aberration curve diagram of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 10 is the lateral chromatic aberration curve diagram of the optical lens in Embodiment 2 of the present invention.

[0035] Figure 11 is a schematic structural diagram of the optical lens in Embodiment 3 of the present invention.

[0036] Figure 12 is the field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0037] Figure 13 is the F-Theta distortion curve diagram of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 14 This is the axial aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0039] Figure 15 This is the lateral chromatic aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0040] Figure 16 This is the structural schematic diagram of the optical lens in Embodiment 4 of the present invention.

[0041] Figure 17 This is the field curvature curve graph of the optical lens in Embodiment 4 of the present invention.

[0042] Figure 18 This is the F-Theta distortion curve graph of the optical lens in Embodiment 4 of the present invention.

[0043] Figure 19 This is the axial aberration curve graph of the optical lens in Embodiment 4 of the present invention.

[0044] Figure 20 This is the lateral chromatic aberration curve graph of the optical lens in Embodiment 4 of the present invention.

[0045] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0046] To better understand the present application, various aspects of the present application will be described in more detail 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.

[0047] It should be noted that in this specification, the expressions such as first, second, and third 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.

[0048] In the drawings, for the sake of clarity, the thickness, dimensions, and shape of the lenses 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 only examples and are not drawn to an exact scale.

[0049] In this text, 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 to be 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.

[0050] It should also be understood that the terms "comprises," "comprising," "has," "including," and / or "including having," when used in this specification, denote 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. In addition, when an expression such as "at least one of..." appears after a list of listed features, it modifies the entire list of listed features, rather than modifying an individual element in the list. In addition, when describing 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.

[0051] 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 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.

[0052] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0053] The optical lens provided by the embodiment of the present invention comprises a total of eight lenses, and the optical lens sequentially includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens along the optical axis from the object side to the imaging surface.

[0054] In some embodiments, the first lens may have a negative focal power, with its object side being convex and its image side being concave. The second lens may have a negative focal power, with its object side being concave near the optical axis and its image side being concave. The third lens may have a positive focal power, with its object side being convex near the optical axis and its image side may be concave or convex. The fourth lens may have a positive focal power, with its object side being concave and its image side being convex. The fifth lens may have a positive focal power, with its object side being convex and its image side being convex. The sixth lens may have a negative focal power, with its object side may be concave or convex and its image side being concave. The seventh lens may have a positive focal power, with its object side being convex and its image side being convex. The eighth lens may have a negative focal power, with its object side being convex near the optical axis and its image side being concave.

[0055] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the fourth lens and the fifth lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the imaging. When the diaphragm is located between the fourth lens and the fifth lens, it is convenient for the correction of diaphragm aberration.

[0056] 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.

[0057] In some embodiments, the total optical length TTL of the optical lens and the f-number Fno of the optical lens satisfy: 7.8mm < TTL / Fno < 8.5mm. By satisfying the above conditional formula, by controlling the relationship between the total length and the f-number of the optical lens, it is ensured that the optical lens can meet the requirements of large aperture and miniaturization design, and provide sufficient light transmission for camera shooting to meet the needs of high-quality and high-definition shooting.

[0058] In some embodiments, the true image height ih corresponding to the maximum half field of view angle of the optical lens, the effective focal length f of the optical lens, and the radian value θ of the maximum half field of view angle of the optical lens satisfy: 0.96 / rad < ih / (f×θ) < 1.04 / rad. By satisfying the above conditional formula, it is possible to control the optical lens to have small distortion and improve the imaging quality of the optical lens.

[0059] In some embodiments, the true image height ih corresponding to the maximum half field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 2.6 < ih / EPD < 2.9. By satisfying the above conditional formula, the optical lens can have a larger entrance pupil diameter and higher light transmission, thereby increasing the imaging effect when the optical lens works in a dark environment and reducing the aberration of the edge field of view.

[0060] In some embodiments, the effective focal length f of the optical lens and the radian value θ of the maximum half field of view angle of the optical lens satisfy: 0.8 mm / rad < f / θ < 0.87 mm / rad. By satisfying the above conditional formula, while the optical lens has sufficient focal length, it has a relatively large field of view angle to meet the requirement of the shooting range, which is beneficial to reducing the deflection angle of light, thereby better balancing the aberration of the optical lens, and is beneficial to compressing the length of the optical lens in the optical axis direction.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -3.5 < f2 / f < -2.4. By satisfying the above conditional formula, the second lens has the effect of diverging light. Under the same field of view angle, the light emerging from the image side of the first lens is further diverged, and the central light and edge light of each field can be dispersed, enabling the rear optical system to have a larger light receiving surface to receive the light emerging from the image side of the second lens, achieving a larger light entrance amount, which is beneficial to increasing the relative illumination.

[0062] In some embodiments, the effective focal length f of the optical lens and the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens satisfy: 3.2 < f1234 / f < 9.5. By satisfying the above conditional formula, by setting the front diaphragm lens group to have a relatively large refractive power, it is beneficial for large-angle light to enter the optical lens to achieve a large field of view angle of the optical lens, and it is also beneficial to improve the light flux of the optical lens and better achieve a large aperture of the optical lens.

[0063] In some embodiments, the effective focal length f of the optical lens and the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy: 2.2 < f5678 / f < 2.8. By satisfying the above conditional formula, by reasonably setting the positive refractive power of the rear diaphragm lens group, it is beneficial to balance the distortion and astigmatism generated by the front-end lens of the optical lens and improve the imaging quality of the optical lens.

[0064] In some embodiments, the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy: 1.2 < f1234 / f5678 < 4.2. By satisfying the above conditional formula, by reasonably setting the focal length relationship of each lens group before and after the diaphragm, the lens can have a relatively large field of view angle while correcting various aberrations of the optical lens and improving the imaging quality of the optical lens.

[0065] In some embodiments, the radius of curvature R15 of the object side surface of the eighth lens and the radius of curvature R16 of the image side surface of the eighth lens satisfy: 2.2 < (R15 + R16) / (R15 - R16) < 3.4. Satisfying the above conditional formula reduces the light converging ability of the eighth lens, plays a role in stably irradiating light onto the imaging surface, and at the same time enables more peripheral light to reach the imaging surface, improving the illuminance and light transmission of the optical lens field of view and reducing the sensitivity of the lens.

[0066] In some embodiments, the clear aperture semi-diameter CSD11 at the object side end of the first lens and the clear aperture semi-diameter CSD81 at the object side end of the eighth lens satisfy: 2.3 < CSD11 / CSD81 < 3. Satisfying the above conditional formula enables the optical lens to have a larger aperture, better realizes the collection of large-angle light, realizes the ultra-wide-angle imaging of the optical lens, and at the same time can increase the imaging area of the optical lens and realize the large target surface imaging of the optical lens.

[0067] In some embodiments, the sagitta corresponding to the maximum clear aperture semi-diameter at the image side end of the second lens and the central thickness CT2 of the second lens along the optical axis satisfy: 0.8 < SAGX22 / CT2 < 1.3. Satisfying the above conditional formula can reasonably control the surface shape of the second lens, which is beneficial to reducing the deflection angle of light in the optical lens, thereby reducing the sensitivity of the marginal light of the optical lens and improving the resolution.

[0068] In some embodiments, the true image height ih corresponding to the maximum half field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.8 < ih / f < 1.9. Satisfying the above conditional formula controls the image height and focal length of the optical lens within a reasonable range, which helps the optical lens to have the characteristic of a large image surface, and at the same time improves the resolution of the optical lens and the imaging quality.

[0069] In some embodiments, the sum ΣCT of the central thicknesses of the first lens to the eighth lens along the optical axis and the optical total length TTL of the optical lens satisfy: 0.55 < ΣCT / TTL < 0.65. Satisfying the above conditional formula reasonably configures the optical total length of the optical lens and the sum of the thicknesses of each lens, which helps to realize the high pixel characteristic and improve the imaging quality of the optical lens.

[0070] In some embodiments, the central thickness CT7 of the seventh lens along the optical axis and the edge thickness ET7 of the seventh lens satisfy: 2.6 < CT7 / ET7 < 3. Satisfying the above conditional formula, by controlling the thickness ratio of the seventh lens within a certain range, the seventh lens will not be locally too thick, which is beneficial to the processing and forming of the lens, thereby facilitating the reduction of the assembly difficulty, and the surface curvature change of the seventh lens is reasonable, which can effectively correct the field curvature of the system.

[0071] In some embodiments, the central thickness CT8 of the eighth lens along the optical axis and the edge thickness ET8 of the eighth lens satisfy: 0.4 < CT8 / ET8 < 0.6. Satisfying the above conditional formula reasonably limits the central thickness and edge thickness of the eighth lens, ensures that the last lens is not easily deformed during the assembly process, is very helpful for the stability of field curvature, has a larger forming and debugging process space, avoids stray light risks caused by appearance problems of the eighth lens, and can also better balance the distortion and astigmatism of the entire optical lens.

[0072] In some embodiments, the object-side curvature radius R1 of the first lens and the image-side curvature radius R2 of the first lens satisfy: 1.8 < (R1 + R2) / (R1 - R2) < 2.1. Satisfying the above conditional formula can make the object side and the image side close to a concentric circle structure, reduce the light-gathering ability of the first lens, and play a role in smoothly transitioning light.

[0073] In some embodiments, the focal length f1 of the first lens, the object-side curvature radius R1 of the first lens, and the image-side curvature radius R2 of the first lens satisfy: -0.5 < f1 / (R1 + R2) < -0.4. Satisfying the above conditional formula can constrain the surface shapes of the object side and the image side of the first lens, is beneficial to reducing the bending degree of light at the image side of the first lens, reducing the astigmatism of the optical system, ensuring that the optical lens has a large field of view angle while having small distortion, and thus improving the imaging quality.

[0074] In some embodiments, the object-side curvature radius R1 of the first lens and the sagitta SAGX11 corresponding to the maximum clear aperture at the object-side end of the first lens satisfy: 5.1 < R1 / SAGX11 < 6.3. Satisfying the above conditional formula can control the ratio relationship between the curvature radius of the object side of the first lens and the sagitta at the maximum effective aperture, provide negative refractive power for the optical lens, thereby capturing the light rays entering the optical lens at large angles, and expanding the field of view angle range of the optical lens.

[0075] In some embodiments, the optical lens satisfies the conditional formula: 1.5 mm < f < 1.6 mm, 210° ≤ FOV ≤ 220°, 1 mm < EPD < 1.2 mm; 1.4 < Fno < 1.6; 2.9 mm < ih < 3 mm; where f represents the effective focal length of the optical lens, TTL represents the optical total length of the optical lens, FOV represents the maximum field of view angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, Fno represents the aperture value of the optical lens, and ih represents the true image height corresponding to the maximum half field of view angle of the optical lens. Satisfying the above conditional formula, the optical lens has at least one or more advantages such as ultra-wide angle, large aperture, high pixel, and large target surface characteristics.

[0076] In some embodiments, all eight lenses in the optical lens can be made of plastic lenses or adopt a structure with a combination of glass and plastic materials. Preferably, the optical lens of the present invention adopts a lens structure with a combination of eight glass and plastic materials. Specifically, the first lens and the fourth lens can be made of glass lenses, and the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are all plastic lenses. Adopting a glass-plastic hybrid structure can improve the thermal stability performance, effectively reduce costs, correct aberrations, reduce the volume, and provide an optical lens product with higher cost performance.

[0077] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens can adopt 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, in the optical lens provided by the present invention, the first lens and the fourth lens can adopt spherical lenses, and the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens can adopt aspherical lenses.

[0078] In each embodiment of the present invention, when the lens adopts an aspherical lens, the surface shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0079] ;

[0080] where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and B, C, D, E, F, G, and H are the surface coefficients of the fourth order, sixth order, eighth order, tenth order, twelfth order, fourteenth order, and sixteenth order, respectively.

[0081] The present invention will be further described in multiple embodiments below. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are slightly different. For specific differences, please refer to the parameter tables of each embodiment. The following embodiments are only the 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 all included in the protection scope of the present invention.

[0082] Embodiment 1

[0083] Please refer to Figure 1, as shown is a schematic structural diagram of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 sequentially includes, along the optical axis from the object side to the imaging surface S19: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a diaphragm ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter G1.

[0084] Among them, the first lens L1 has a negative optical power. Its object side surface S1 is a convex surface, and its image side surface S2 is a concave surface;

[0085] The second lens L2 has a negative optical power. Its object side surface S3 is a concave surface near the optical axis, and its image side surface S4 is a concave surface;

[0086] The third lens L3 has a positive optical power. Its object side surface S5 is a convex surface near the optical axis, and its image side surface S6 is a concave surface;

[0087] The fourth lens L4 has a positive optical power. Its object side surface S7 is a concave surface, and its image side surface S8 is a convex surface;

[0088] The fifth lens L5 has a positive optical power. Its object side surface S9 is a convex surface, and its image side surface S10 is a convex surface;

[0089] The sixth lens L6 has a negative optical power. Its object side surface S11 is a concave surface, and its image side surface S12 is a concave surface;

[0090] The seventh lens L7 has a positive optical power. Its object side surface S13 is a convex surface, and its image side surface S14 is a convex surface;

[0091] The eighth lens L8 has a negative optical power. Its object side surface S15 is a convex surface near the optical axis, and its image side surface S16 is a concave surface;

[0092] Both the object side surface S17 and the image side surface S18 of the filter G1 are flat surfaces;

[0093] The imaging surface S19 is a flat surface.

[0094] The first lens L1 and the fourth lens L4 adopt glass spherical lenses; the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 all adopt plastic aspherical lenses.

[0095] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0096] Table 1-1

[0097]

[0098] The surface type parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0099] Table 1-2

[0100]

[0101] In this embodiment, the field curvature curve graph, F-Theta distortion curve graph, axial aberration curve graph, and lateral chromatic aberration curve graph of the optical lens 100 are respectively as Figure 2 , Figure 3 , Figure 4 and Figure 5 shown.

[0102] Figure 2 shows the field curvature curve graph in this embodiment, which represents the field curvature of light rays in the meridional image plane and the sagittal image plane. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the semi-field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.05 mm, indicating that the optical lens 100 can correct the field curvature well.

[0103] Figure 3 shows the F-Theta distortion curve graph in this embodiment, which represents the distortion at different field angles on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the semi-field angle (unit: °). It can be seen from the figure that the distortion value is controlled within -2% to 9%, indicating that the optical lens 100 can correct the distortion well.

[0104] Figure 4 shows the axial aberration curve graph in this embodiment, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. It can be seen from the figure that the offset of the axial aberration is controlled within ±0.02 mm, indicating that the optical lens 100 can correct the axial aberration well.

[0105] Figure 5 shows the lateral chromatic aberration curve graph in this embodiment, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.555 μm) at different image heights on the imaging plane. The horizontal axis represents the lateral chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. It can be seen from the figure that the lateral chromatic aberration between the longest wavelength and the shortest wavelength is controlled within 0 to 4 μm, indicating that the optical lens 100 can correct the lateral chromatic aberration well.

[0106] Embodiment 2

[0107] Please refer to Figure 6 , which shows the schematic structural diagram of the optical lens 200 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.

[0108] In the optical lens 200 in Embodiment 2, the relevant parameters of each lens are shown in Table 2-1.

[0109] Table 2-1

[0110]

[0111] The surface shape parameters of the aspherical lens of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0112] Table 2-2

[0113]

[0114] In this embodiment, the field curvature curve graph, F-Theta distortion curve graph, axial aberration curve graph, and lateral chromatic aberration curve graph of the optical lens 200 are respectively as Figure 7 , Figure 8 , Figure 9 and Figure 10 shown.

[0115] From Figure 7 it can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.05 mm, indicating that the optical lens 200 can correct the field curvature well.

[0116] From Figure 8 it can be seen that the distortion value is controlled within -4% to 10%, indicating that the optical lens 200 can correct the distortion well.

[0117] From Figure 9 it can be seen that the offset of the axial aberration is controlled within -0.04 mm to 0.02 mm, indicating that the optical lens 200 can correct the axial aberration well.

[0118] From Figure 10 it can be seen that the lateral chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -2 μm to 5 μm, indicating that the optical lens 200 can correct the lateral chromatic aberration well.

[0119] Embodiment 3

[0120] Please refer to Figure 11 , which shows the structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present invention. Compared with Embodiment 1, the main difference is that: the object side surface S11 of the sixth lens L6 is convex near the optical axis; the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0121] In the optical lens 300 in Embodiment 3, the relevant parameters of each lens are shown in Table 3-1.

[0122] Table 3-1

[0123]

[0124] The surface shape parameters of the aspherical lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0125] Table 3-2

[0126]

[0127] In this embodiment, the field curvature curve graph, F-Theta distortion curve graph, axial aberration curve graph, and lateral chromatic aberration curve graph of the optical lens 300 are respectively as Figure 12 , Figure 13 , Figure 14 and Figure 15 shown.

[0128] From Figure 12 it can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.05 mm, indicating that the optical lens 300 can correct the field curvature well.

[0129] From Figure 13 it can be seen that the distortion value is controlled within -3% to 10%, indicating that the optical lens 300 can correct the distortion well.

[0130] From Figure 14 it can be seen that the offset of the axial aberration is controlled within ±0.03 mm, indicating that the optical lens 300 can correct the axial aberration well.

[0131] From Figure 15 it can be seen that the lateral chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±4 μm, indicating that the optical lens 300 can correct the lateral chromatic aberration well.

[0132] Embodiment 4

[0133] Please refer to Figure 16 , which shows the structural schematic diagram of the optical lens 400 provided in Embodiment 4 of the present invention. Compared with Embodiment 1, the main difference is that: the image side surface S6 of the third lens L3 is a convex surface; the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0134] The relevant parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0135] Table 4-1

[0136]

[0137] The surface shape parameters of the aspherical lens of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0138] Table 4-2

[0139]

[0140] In this embodiment, the field curvature curve graph, F-Theta distortion curve graph, axial aberration curve graph, and lateral chromatic aberration curve graph of the optical lens 400 are respectively as shown in Figure 17 , Figure 18 , Figure 19 and Figure 20 shown.

[0141] It can be seen from Figure 17 that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.05 mm, indicating that the optical lens 400 can well correct the field curvature.

[0142] It can be seen from Figure 18 that the distortion value is controlled within 0-10%, indicating that the optical lens 400 can better correct the distortion.

[0143] It can be seen from Figure 19 that the offset of the axial aberration is controlled within -0.03 mm to 0.01 mm, indicating that the optical lens 400 can better correct the axial aberration.

[0144] It can be seen from Figure 20 that the lateral chromatic aberration of the longest wavelength and the shortest wavelength is controlled within 0-4 μm, indicating that the optical lens 400 can better correct the lateral chromatic aberration.

[0145] 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 (half image height) corresponding to the maximum half field angle, the chief ray angle of incidence CRA at the maximum image height, the maximum field angle FOV, and the values corresponding to each conditional expression in each embodiment.

[0146] Table 5

[0147]

[0148] Compared with the prior art, the optical lens provided by the present invention has at least the following advantages:

[0149] (1) For the optical lens provided by the present invention, through specific surface shape settings and reasonable optical power distribution, the optical lens has a large aperture and can achieve high-definition imaging even in a relatively dark environment; it can achieve an ultra-wide angle of the lens, thereby being able to obtain more scene information and meeting the requirements of large-range detection of the optical lens.

[0150] (2)The optical lens provided by the present invention has a large image plane, which can well match a large-size chip and ensure good resolution quality. At the same time, it can reasonably correct the overall aberration of the optical lens, making the optical lens have small distortion and high pixels, and improving the imaging quality of the optical lens.

[0151] (3)The optical lens provided by the present invention adopts a hybrid glass and plastic structure, which not only enables the lens to have good thermal stability, improves the stability of the lens under high and low temperature conditions and at the same time improves the imaging quality, but also greatly reduces the production cost of the lens, reduces the volume of the lens, and preferably realizes the miniaturization of the lens.

[0152] 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 any one or more embodiments or examples in a suitable manner.

[0153] The above embodiments only represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on 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 shall be subject to the appended claims.

Claims

1. An optical lens, with a total of eight lenses, characterized in that, It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side is convex and whose image side is concave; A second lens with a negative optical power, whose object side is concave near the optical axis and whose image side is concave; A third lens with a positive optical power, whose object side is convex near the optical axis; A fourth lens with a positive optical power, whose object side is concave and whose image side is convex; A fifth lens with a positive optical power, whose object side is convex and whose image side is convex; A sixth lens with a negative optical power, whose image side is concave; A seventh lens with a positive optical power, whose object side is convex and whose image side is convex; An eighth lens with a negative optical power, whose object side is convex near the optical axis and whose image side is concave; Wherein, the total optical length TTL of the optical lens and the aperture value Fno of the optical lens satisfy: 7.8mm < TTL / Fno < 8.5mm.

2. The optical lens according to claim 1, wherein The true image height ih corresponding to the maximum half field of view angle of the optical lens, the effective focal length f of the optical lens and the radian value θ of the maximum half field of view angle of the optical lens satisfy: 0.96 / rad < ih / (f×θ) < 1.04 / rad.

3. The optical lens according to claim 1, wherein The true image height ih corresponding to the maximum half field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 2.6 < ih / EPD < 2.

9.

4. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the radian value θ of the maximum half field of view angle of the optical lens satisfy: 0.8mm / rad < f / θ < 0.87mm / rad.

5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -3.5 < f2 / f < -2.

4.

6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens satisfy: 3.2 < f1234 / f < 9.5; The effective focal length f of the optical lens and the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: 2.2 < f5678 / f < 2.

8.

7. The optical lens according to claim 1, wherein The combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: 1.2 < f1234 / f5678 < 4.

2.

8. The optical lens according to claim 1, wherein The object side curvature radius R15 of the eighth lens and the image side curvature radius R16 of the eighth lens satisfy: 2.2 < (R15 + R16) / (R15 - R16) < 3.

4.

9. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter CSD11 at the object side end of the first lens and the clear aperture semi-diameter CSD81 at the object side end of the eighth lens satisfy: 2.3 < CSD11 / CSD81 < 3.

10. The optical lens according to claim 1, wherein, The sagitta corresponding to the maximum clear aperture semi-diameter at the image side end of the second lens and the central thickness CT2 of the second lens along the optical axis satisfy: 0.8 < SAGX22 / CT2 < 1.3.

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