Optical lens

Abstract

The invention provides an optical lens, which comprises eight lenses from an object side to an imaging surface along an optical axis: a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power, the object side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has positive focal power, and the image side surface of the fifth lens is a convex surface; the sixth lens has negative focal power, and the object side surface of the sixth lens is a concave surface; the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a convex surface; and the 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, and the optical lens has the advantage 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] In the field of UAV photogrammetry and mapping, the demand for ultra-wide-angle lenses is extremely urgent. At present, most mainstream UAV ultra-wide-angle lenses achieve the shooting effect by expanding the aperture and increasing the size of the lens group to meet various aerial photography tasks. However, such lenses have obvious disadvantages. In complex light and high-contrast scenes, overexposure and underexposure are likely to occur, resulting in a large amount of detail loss. To correct distortion, complex means are adopted, resulting in a sharp increase in the weight, volume, and power consumption of the lens, seriously restricting the performance of UAVs. Summary of the Invention

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

[0004] The present invention provides an optical lens, which has a total of eight lenses, and successively includes, along the optical axis from the object side to the imaging surface: 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; A third lens with a positive optical power, whose object side is convex and whose image side is convex; A fourth lens with a positive optical power, whose object side is convex and whose image side is convex; A fifth lens with a positive optical power, whose image side is convex; A sixth lens with a negative optical power, whose object 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 an optical power, whose image side is concave near the optical axis; Wherein, the aperture value Fno of the optical lens and the optical total length TTL of the optical lens satisfy: 0.13 / mm < Fno / TTL < 0.19 / mm.

[0005] Further preferably, the true 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: 2.7 < IH / f < 3.

[0006] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.8 < f1 / f < -2.2.

[0007] Further preferably, the effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: -1.5 < f12 / f < -1.

[0008] More preferably, the effective focal length f of the optical lens and the combined focal length f38 of the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: 1.1 < f38 / f < 1.9.

[0009] More preferably, the clear aperture semi-diameter CSD11 at the object side end of the first lens and the sag SAGX11 corresponding to the maximum clear aperture semi-diameter at the object side end of the first lens satisfy: 2.3 < CSD11 / SAGX11 < 3.

[0010] More 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: 1.6 < CSD11 / CSD81 < 2.

[0011] More preferably, the focal length f1 of the first lens, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: -1.2 < f1 / (R1 + R2) < -0.8.

[0012] More preferably, the maximum edge thickness value ETmax among the first lens to the eighth lens and the minimum edge thickness value ETmin among the first lens to the eighth lens satisfy: 5.2 < ETmax / ETmin < 7.5.

[0013] More preferably, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 2 < (R1 + R2) / (R1 - R2) < 2.5.

[0014] 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 make the lens have one or more advantages such as miniaturization, large aperture, large field of view angle, small distortion, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, where: Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0016] Figure 2 is an astigmatism curve diagram of the optical lens in Embodiment 1 of the present invention.

[0017] Figure 3It is the F-Theta distortion curve graph of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 4 It is the axial aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 5 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 6 It is the structural schematic diagram of the optical lens in Embodiment 2 of the present invention.

[0021] Figure 7 It is the astigmatism curve graph of the optical lens in Embodiment 2 of the present invention.

[0022] Figure 8 It is the F-Theta distortion curve graph of the optical lens in Embodiment 2 of the present invention.

[0023] Figure 9 It is the axial aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0024] Figure 10 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0025] Figure 11 It is the structural schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0026] Figure 12 It is the astigmatism curve graph of the optical lens in Embodiment 3 of the present invention.

[0027] Figure 13 It is the F-Theta distortion curve graph of the optical lens in Embodiment 3 of the present invention.

[0028] Figure 14 It is the axial aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 15 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0030] Figure 16 It is the structural schematic diagram of the optical lens in Embodiment 4 of the present invention.

[0031] Figure 17 It is the astigmatism curve graph of the optical lens in Embodiment 4 of the present invention.

[0032] Figure 18 It is the F-Theta distortion curve graph of the optical lens in Embodiment 4 of the present invention.

[0033] Figure 19It is the axial aberration curve graph of the optical lens in Embodiment 4 of the present invention.

[0034] Figure 20 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 4 of the present invention.

[0035] Figure 21 It is the structural schematic diagram of the optical lens in Embodiment 5 of the present invention.

[0036] Figure 22 It is the astigmatism curve graph of the optical lens in Embodiment 5 of the present invention.

[0037] Figure 23 It is the F-Theta distortion curve graph of the optical lens in Embodiment 5 of the present invention.

[0038] Figure 24 It is the axial aberration curve graph of the optical lens in Embodiment 5 of the present invention.

[0039] Figure 25 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 5 of the present invention.

[0040] Figure 26 It is the structural schematic diagram of the optical lens in Embodiment 6 of the present invention.

[0041] Figure 27 It is the astigmatism curve graph of the optical lens in Embodiment 6 of the present invention.

[0042] Figure 28 It is the F-Theta distortion curve graph of the optical lens in Embodiment 6 of the present invention.

[0043] Figure 29 It is the axial aberration curve graph of the optical lens in Embodiment 6 of the present invention.

[0044] Figure 30 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 6 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, third, etc. are only used to distinguish one feature from another, and do not represent any limitation on the features. 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 ease of illustration, the thickness, size, 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 only examples and are not drawn to an exact scale.

[0049] 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 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 "containing", 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. 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 an individual element in the list. In addition, 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.

[0051] Unless otherwise defined, all terms used herein (including technical and scientific terms) 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 following will detail the present application with reference to the drawings and in conjunction with the embodiments.

[0053] The optical lens provided by the embodiment of the present invention has a total of eight lenses, which sequentially include: 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 optical power, its object side is convex, and its image side is concave. The second lens may have a negative optical power, its object side is concave, and its image side may be concave or convex. The third lens may have a positive optical power, its object side is convex, and its image side is convex. The fourth lens may have a positive optical power, its object side is convex, and its image side is convex. The fifth lens may have a positive optical power, its object side may be concave or convex, and its image side is convex. The sixth lens may have a negative optical power, its object side is concave, and its image side may be concave or convex. The seventh lens may have a positive optical power, its object side is convex, and its image side is convex. The eighth lens may have a positive or negative optical power, its object side may be concave or convex, and its image side is concave near the optical axis.

[0055] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the second lens and the third lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the image.

[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 aperture value Fno of the optical lens and the total optical length TTL of the optical lens satisfy: 0.13 / mm < Fno / TTL < 0.19 / mm. Satisfying the above conditional formula enables the optical lens to simultaneously take into account the requirements of large aperture and miniaturization design, and at the same time provides sufficient light transmission for shooting, thereby meeting the need for high-quality and high-definition shooting under low-light conditions.

[0058] In some embodiments, the true 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: 2.7 < IH / f < 3. Satisfying the above conditional formula is beneficial to realizing the wide-angle characteristic of the optical lens, thereby meeting the large-range shooting requirements, and can also realize the large image plane characteristic, thereby improving the imaging quality of the optical lens.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.8 < f1 / f < -2.2. By satisfying the above conditional formula and setting the first lens of the optical lens as a lens with a negative optical power, the light rays entering the optical lens at a large angle can be captured, and the field of view angle range of the optical lens can be expanded; meanwhile, it is also beneficial to reduce the sensitivity of the optical lens and achieve the miniaturized design of the optical lens.

[0060] In some embodiments, the effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: -1.5 < f12 / f < -1. By satisfying the above conditions and reasonably distributing the focal lengths of the front lens group composed of the first lens and the second lens, the object surface light with a wide field of view angle can be converged into the lens, better correcting the distortion of the lens without generating large aberrations; meanwhile, the front lens group can have appropriate refractive power, which is beneficial to reducing the total length of the optical lens.

[0061] In some embodiments, the effective focal length f of the optical lens and the combined focal length f38 of the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: 1.1 < f38 / f < 1.9. By satisfying the above conditions and reasonably distributing the focal lengths of the rear lens group composed of the third lens to the eighth lens, 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.

[0062] In some embodiments, the clear aperture semi-diameter CSD11 at the object side end of the first lens and the sagittal height SAGX11 corresponding to the maximum clear aperture semi-diameter at the object side end of the first lens satisfy: 2.3 < CSD11 / SAGX11 < 3. By satisfying the above conditional formula, the optical lens meets the small-aperture design requirements, which is beneficial to compressing the central field of view of the optical lens and making the imaging quality of the edge field better.

[0063] 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: 1.6 < CSD11 / CSD81 < 2. By satisfying the above conditional formula and controlling the ratio of the clear aperture semi-diameter at the object side end of the first lens to the clear aperture semi-diameter at the object side end of the eighth lens, the optical lens can have a smaller aperture size, which is convenient for being mounted on an unmanned aerial vehicle device; meanwhile, it ensures that the optical lens can collect light rays at a large angle, achieve large-field-of-view imaging of the optical lens, increase the imaging area of the optical lens, and improve the imaging quality.

[0064] In some embodiments, the focal length f1 of the first lens, the curvature radius R1 of the object side surface of the first lens, and the curvature radius R2 of the image side surface of the first lens satisfy: -1.2 < f1 / (R1 + R2) < -0.8. By satisfying the above conditional formula, the surface shapes of the object side surface and the image side surface of the first lens can be constrained, which is beneficial to reducing the bending degree of light at the image side surface of the first lens, reducing the astigmatism of the optical lens, so as to balance the astigmatism problem brought by the large field of view angle of the optical lens, so that the astigmatism of the optical lens will not be too large while having a large field of view, and thus ensure that the optical lens has excellent imaging quality.

[0065] In some embodiments, the maximum edge thickness value ETmax among the first lens to the eighth lens and the minimum edge thickness value ETmin among the first lens to the eighth lens satisfy: 5.2 < ETmax / ETmin < 7.5. By satisfying the above conditional formula, in order to achieve the miniaturized design of the optical lens, the ratio of the maximum edge thickness value of the eight lenses of the optical lens to the minimum edge thickness value of the eight lenses of the optical lens is controlled to reduce the total length of the optical lens, and it is helpful to reduce the distortion and aberration of the optical lens, and the imaging quality of the optical lens can be improved.

[0066] In some embodiments, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 2 < (R1 + R2) / (R1 - R2) < 2.5. By satisfying the above conditional formula, by reasonably defining the shapes of the object side surface and the image side surface of the first lens, the distortion generated by the first lens can be reduced, the difficulty of distortion correction of the subsequent lens can be reduced, and it is helpful to improve the imaging quality.

[0067] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the eighth lens along the optical axis respectively satisfy: 1.3 < TTL / ∑CT < 1.4. By satisfying the above conditional formula, reasonably configuring the total optical length of the optical lens and the sum of the thicknesses of each lens helps to achieve high pixel characteristics and improve the imaging quality of the optical lens; at the same time, it can effectively shorten the total optical length of the optical lens and meet the requirements of miniaturization and lightweight design.

[0068] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.6 < f2 / f < -2.2. By satisfying the above conditional formula, it is beneficial to cooperate with the first lens to make large-angle light enter the optical lens, thereby expanding the field of view angle of the optical lens, and at the same time, it is also beneficial to correct the astigmatism and chromatic aberration of the optical lens and improve the imaging quality of the optical lens.

[0069] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1.9 < f3 / f < 2.2. By satisfying the above conditional formula, by providing the third lens with a positive optical power and defining the ratio of the focal length of the third lens to the effective focal length of the optical lens, it is beneficial to adjust the light path from the first lens and the second lens, enabling the optical lens to have characteristics of a certain large field of view angle, low sensitivity, and miniaturization.

[0070] In some embodiments, the distance CT12 between the first lens and the second lens on the optical axis and the overall optical length TTL of the optical lens satisfy: 0.1 < CT12 / TTL < 0.13. By satisfying the above conditional formula, by reasonably restricting the air gap between the first lens and the second lens, the light deflection can tend to be slow, which is beneficial to reducing the sensitivity of the optical lens.

[0071] In some embodiments, the sagittal height SAGX11 corresponding to the maximum clear aperture semi-diameter at the object side end of the first lens and the central thickness CT1 of the first lens satisfy: 0.6 < SAGX11 / CT1 < 0.9. By satisfying the above conditional formula, by controlling the ratio of the sagittal height of the object side surface of the first lens to the central thickness of the first lens on the optical axis, the surface shape of the object side surface can be biased towards being curved; at the same time, a larger sagittal height is beneficial for the first lens to collect light with a large field of view, achieving high angular resolution at the center of the optical lens, and thus improving the imaging quality of the central region.

[0072] In some embodiments, the optical lens satisfies the conditional formula: 1.2 mm < f < 1.7 mm, 8.2 mm < TTL < 10.2 mm, 1.4 < Fno < 1.6, 4 mm < IH < 4.6 mm, 165° < FOV < 185°, where f represents the effective focal length of the optical lens, TTL represents the overall optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, and FOV represents the maximum field of view angle of the optical lens. By satisfying the above conditions, it shows that the optical lens provided by the embodiments of the present invention at least has: a large aperture, enabling the lens to achieve high-definition imaging even in a relatively dark environment; a large field of view angle, allowing for a large field of view range; a short overall length, which is beneficial for better realizing the miniaturization and portability of the device.

[0073] In some embodiments, the eight lenses in the optical lens can all 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, which can improve the thermal stability performance. 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 and plastic hybrid structure can effectively reduce costs, correct aberrations, reduce volume, and provide an optical lens product with higher cost performance.

[0074] 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 may 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, in the optical lens provided by the present invention, 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 are all aspherical lenses.

[0075] In various embodiments of the present invention, when the lens is an aspherical lens, the aspherical surface shapes of the optical lens satisfy the following equation: ; 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 conic coefficients of the fourth order, sixth order, eighth order, tenth order, twelfth order, fourteenth order, and sixteenth order, respectively.

[0076] 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 to the following embodiments. Any 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.

[0077] Embodiment 1 Please refer to Figure 1 , which shows 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 diaphragm ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter G1; 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; The second lens L2 has a negative optical power. Its object side surface S3 is a concave surface, and its image side surface S4 is a concave surface near the optical axis; The third lens L3 has a positive optical power. Its object side surface S5 is a convex surface, and its image side surface S6 is a convex surface; The fourth lens L4 has a positive optical power. Its object side surface S7 is a convex surface, and its image side surface S8 is a convex surface; The fifth lens L5 has a positive optical power. Its object side S9 is concave near the optical axis, and its image side S10 is convex. The sixth lens L6 has a negative optical power. Its object side S11 is concave, and its image side S12 is concave. The seventh lens L7 has a positive optical power. Its object side S13 is convex, and its image side S14 is convex. The eighth lens L8 has a positive optical power. Its object side S15 is convex near the optical axis, and its image side S16 is concave near the optical axis. Both the object side S17 and the image side S18 of the filter G1 are flat. The imaging surface S19 is flat.

[0078] The first lens L1 and the fourth lens L4 are glass aspherical 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 are all plastic aspherical lenses.

[0079] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0080] Table 1-1 The surface type parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0081] Table 1-2 In this embodiment, the astigmatism 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 , Figure 5 shown.

[0082] Figure 2 shows the astigmatism curve graph of the optical lens 100 in this embodiment, which represents the astigmatism 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 astigmatism of the meridional image plane and the sagittal image plane is controlled within ±0.1 mm, indicating that the optical lens 100 can correct astigmatism well.

[0083] Figure 3The F-Theta distortion curve of the optical lens 100 in Embodiment 1 is shown, which represents the F-Theta distortion of light rays at different image heights on the imaging surface. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the F-Theta distortion of the optical lens is controlled within ±10%, indicating that the optical lens 100 can correct the distortion well.

[0084] Figure 4 The axial aberration curve diagram of the optical lens 100 in this embodiment is shown, which represents the 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. 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.

[0085] Figure 5 The lateral chromatic aberration curve diagram of the optical lens 100 in this embodiment is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.555 μm) at different image heights on the imaging surface. 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 -1 μm to 3 μm, indicating that the optical lens 100 can correct the chromatic aberration well.

[0086] Embodiment 2 Please refer to Figure 6 , which shows the structural schematic diagram of the optical lens 200 provided in Embodiment 2 of the present invention. Compared with Embodiment 1, the main differences are as follows: The image side surface S4 of the second lens L2 is a convex surface; the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0087] The relevant parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0088] Table 2-1 The surface type parameters of the aspherical lens of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0089] Table 2-2 In this embodiment, the astigmatism curve diagram, F-Theta distortion curve diagram, axial aberration curve diagram, and lateral chromatic aberration curve diagram of the optical lens 200 are respectively as Figure 7 , Figure 8 , Figure 9 , Figure 10 shown.

[0090] FromFigure 7 It can be seen that the astigmatism of the meridional image plane and the sagittal image plane is controlled within ±0.2 mm, indicating that the optical lens 200 can correct astigmatism well. From Figure 8 It can be seen that the F-Theta distortion of the optical lens is controlled within -8% to 10%, indicating that the optical lens 200 can correct distortion well. From Figure 9 It can be seen that the offset of the axial aberration is controlled within ±0.02 mm, indicating that the optical lens 200 can correct axial aberration well. From Figure 10 It can be seen that the lateral chromatic aberration between the longest wavelength and the shortest wavelength is controlled within -1 μm to 2 μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0091] Embodiment 3 Please refer to Figure 11 , which shows a schematic structural 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 S9 of the fifth lens L5 is a convex surface; the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0092] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0093] Table 3-1 The surface type parameters of the aspherical lenses of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0094] Table 3-2 In this embodiment, the astigmatism 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 , Figure 15 shown.

[0095] From Figure 12 It can be seen that the astigmatism of the meridional image plane and the sagittal image plane is controlled within ±0.1 mm, indicating that the optical lens 300 can correct astigmatism well. From Figure 13 It can be seen that the F-Theta distortion of the optical lens is controlled within -7% to 10%, indicating that the optical lens 300 can correct distortion well. From Figure 14 It can be seen that the offset of the axial aberration is controlled within ±0.02 mm, indicating that the optical lens 300 can correct axial aberration well. From Figure 15It can be seen that the vertical chromatic aberration between the longest wavelength and the shortest wavelength is controlled within -1μm to 2μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0096] Example 4 Please refer to Figure 16 , which shows the structural schematic diagram of the optical lens 400 provided in Example 4 of the present invention. Compared with Example 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 400 in Example 4 are shown in Table 4-1.

[0098] Table 4-1 The surface type parameters of the aspherical lenses in the optical lens 400 in Example 4 are shown in Table 4-2.

[0099] Table 4-2 In this embodiment, the astigmatism curve graph, F-Theta distortion curve graph, axial aberration curve graph, and vertical chromatic aberration curve graph of the optical lens 400 are respectively as Figure 17 , Figure 18 , Figure 19 , Figure 20 shown.

[0100] From Figure 17 it can be seen that the astigmatism between the meridional image plane and the sagittal image plane is controlled within ±0.2mm, indicating that the optical lens 400 can correct astigmatism well. From Figure 18 it can be seen that the F-Theta distortion of the optical lens is controlled within ±10%, indicating that the optical lens 400 can correct distortion well. From Figure 19 it can be seen that the offset of the axial aberration is controlled within ±0.02mm, indicating that the optical lens 400 can correct axial aberration well. From Figure 20 it can be seen that the vertical chromatic aberration between the longest wavelength and the shortest wavelength is controlled within -1μm to 2μm, indicating that the optical lens 400 can correct chromatic aberration well.

[0101] Example 5 Please refer to Figure 21 , which shows the structural schematic diagram of the optical lens 500 provided in Example 5 of the present invention. Compared with Example 1, the main difference is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0102] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0103] Table 5-1 The surface parameters of the aspherical lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0104] Table 5-2 In this embodiment, the astigmatism curve graph, F-Theta distortion curve graph, axial aberration curve graph, and lateral chromatic aberration curve graph of the optical lens 500 are respectively as Figure 22 , Figure 23 , Figure 24 , Figure 25 shown.

[0105] From Figure 22 it can be seen that the astigmatism between the meridional image plane and the sagittal image plane is controlled within -0.3 mm to 0.1 mm, indicating that the optical lens 500 can correct astigmatism well. From Figure 23 it can be seen that the F-Theta distortion of the optical lens is controlled within -8% to 12%, indicating that the optical lens 500 can correct distortion well. From Figure 24 it can be seen that the offset of the axial aberration is controlled within ±0.05 mm, indicating that the optical lens 500 can correct axial aberration well. From Figure 25 it can be seen that the lateral chromatic aberration between the longest wavelength and the shortest wavelength is controlled within 0 to 2 μm, indicating that the optical lens 500 can correct chromatic aberration well.

[0106] Example 6 Please refer to Figure 26 , which shows the structural schematic diagram of the optical lens 600 provided in Embodiment 6 of the present invention. Compared with Embodiment 1, the main differences are that: the eighth lens L8 has a negative optical power; the image side surface S12 of the sixth lens L6 is a convex surface; the object side surface S15 of the eighth lens L8 is a concave surface; the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0107] The relevant parameters of each lens in the optical lens 600 in Example 6 are shown in Table 6-1.

[0108] Table 6-1 The surface parameters of the aspherical lens of the optical lens 600 in Example 6 are shown in Table 6-2.

[0109] Table 6-2 In this embodiment, the astigmatism curve graph, F-Theta distortion curve graph, axial aberration curve graph, and lateral chromatic aberration curve graph of the optical lens 600 are respectively as shown in Figure 27 , Figure 28 , Figure 29 , Figure 30 .

[0110] It can be seen from Figure 27 that the astigmatism between the meridional image plane and the sagittal image plane is controlled within -0.2 mm to 0.1 mm, indicating that the optical lens 600 can correct astigmatism well. It can be seen from Figure 28 that the F-Theta distortion of the optical lens is controlled within -8% to 12%, indicating that the optical lens 600 can correct distortion well. It can be seen from Figure 29 that the offset of the axial aberration is controlled within ±0.03 mm, indicating that the optical lens 600 can correct axial aberration well. It can be seen from Figure 30 that the lateral chromatic aberration between the longest wavelength and the shortest wavelength is controlled within -1 μm to 3 μm, indicating that the optical lens 600 can correct chromatic aberration well.

[0111] Please refer to Table 7 for the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the overall optical length TTL, the aperture value Fno, the true image height IH corresponding to the maximum field of view angle, the chief ray angle of incidence CRA at the maximum image height, the maximum field of view angle FOV, and the values corresponding to each conditional formula in each embodiment.

[0112] Table 7 In summary of the above embodiments, the optical lens provided by the present invention adopts an eight-piece glass-plastic hybrid structure. Through specific surface shape settings and reasonable optical power distribution, the structure of the optical lens is relatively compact, effectively shortening the overall length of the optical lens, which is conducive to miniaturization; it has a large aperture, enabling the lens to achieve high-definition imaging even in a relatively dark environment; at the same time, it has a large field of view angle and a large viewing range. In addition, it can reasonably correct the overall aberration of the optical lens, with the characteristics of small distortion and high pixels, improving the imaging quality of the optical lens.

[0113] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", "some examples", etc. mean 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.

[0114] The above-described embodiments merely 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 to the scope of the patent for 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 fall within the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention shall be subject to the appended claims.

Claims

1. An optical lens, consisting of eight lenses in total, 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 surface is convex and whose image side surface is concave; A second lens with a negative optical power, whose object side surface is concave; A third lens with a positive optical power, whose object side surface is convex and whose image side surface is convex; A fourth lens with a positive optical power, whose object side surface is convex and whose image side surface is convex; A fifth lens with a positive optical power, whose image side surface is convex; A sixth lens with a negative optical power, whose object side surface is concave; A seventh lens with a positive optical power, whose object side surface is convex and whose image side surface is convex; An eighth lens with an optical power, whose image side surface is concave near the optical axis; Wherein, the aperture value Fno of the optical lens and the overall optical length TTL of the optical lens satisfy: 0.13 / mm < Fno / TTL < 0.19 / mm.

2. The optical lens according to claim 1, wherein The true 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: 2.7 < IH / f < 3.

3. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.8 < f1 / f < -2.

2.

4. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the combined focal length f12 of the first lens and the second lens satisfy: -1.5 < f12 / f < -1.

5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the combined focal length f38 of the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: 1.1 < f38 / f < 1.

9.

6. The optical lens according to claim 1, wherein The clear aperture semi-diameter CSD11 at the object side end of the first lens and the sagitta SAGX11 corresponding to the maximum clear aperture semi-diameter at the object side end of the first lens satisfy: 2.3 < CSD11 / SAGX11 < 3.

7. 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: 1.6 < CSD11 / CSD81 < 2.

8. The optical lens according to claim 1, wherein, The focal length f1 of the first lens, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: -1.2 < f1 / (R1 + R2) < -0.

8.

9. The optical lens according to claim 1, characterized in that, The maximum edge thickness value ETmax among the first lens to the eighth lens and the minimum edge thickness value ETmin among the first lens to the eighth lens satisfy: 5.2 < ETmax / ETmin < 7.

5.

10. The optical lens according to claim 1, characterized in that, The curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 2 < (R1 + R2) / (R1 - R2) < 2.5.

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