Optical lens

Abstract

The application provides an optical lens, which comprises eight lenses in sequence from an object side to an imaging surface along an optical axis, and the eight lenses comprise: a first lens with negative optical power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; a second lens with negative optical power, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a concave surface; a third lens with positive optical power, the object side surface of the third lens is a convex surface; a fourth lens with negative optical power, the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; a fifth lens with positive optical power, the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; a sixth lens with negative optical power, the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a concave surface; a seventh lens with positive optical power, 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 an eighth lens with negative optical power, the object side surface of the eighth lens is a convex surface near the optical axis, and the image side surface of the eighth lens is a concave surface. The optical lens provided by the application improves the imaging quality through specific surface shape matching and reasonable optical power distribution.

Description

Technical Field

[0001] This invention relates to the technical field of imaging lenses, and in particular to an optical lens. Background Technology

[0002] With the rapid development of fields such as drones, security, automobiles, meteorology, medical, VR, and AR, increasingly higher demands are being placed on the field of view of the lenses they are equipped with. Wide-angle lenses, by introducing barrel distortion, compress light at the edges of the field of view as much as possible, thus achieving an ultra-wide-angle lens with a field of view exceeding 220°. Currently, ultra-wide-angle lenses still have many problems. For example, common ultra-wide-angle lenses have relatively small apertures, resulting in insufficient light intake and unclear images. Additionally, aberration correction is difficult, and there are issues such as excessively large lens heads. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide an optical lens with the advantage of excellent image quality.

[0004] This invention provides an optical lens comprising eight lenses with optical power, arranged sequentially along the optical axis from the object side to the imaging plane:

[0005] The first lens with negative optical power has a convex object side and a concave image side.

[0006] A second lens with negative optical power has a concave object side and a concave image side.

[0007] A third lens with positive optical power has a convex object-side surface;

[0008] The fourth lens with negative optical power has a concave object side and a convex image side.

[0009] The fifth lens with positive optical power has a convex object-side surface and a convex image-side surface.

[0010] The sixth lens has negative optical power, with both its object-side and image-side surfaces being concave.

[0011] The seventh lens with positive optical power has a convex object-side surface and a convex image-side surface.

[0012] The eighth lens with negative optical power has an object-side surface that is convex near the optical axis and an image-side surface that is concave.

[0013] Wherein, the effective focal length f of the optical lens, the aperture value Fno of the optical lens, and the total optical length TTL of the optical lens satisfy: 0.18 <f×Fno / TTL<0.2。

[0014] Further preferably, the combined focal length f123 of the first lens, the second lens and the third lens and the effective focal length f of the optical lens satisfy: -3<f123 / f<-2.3.

[0015] Further preferably, the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 1.45<f45678 / f<1.65.

[0016] Further preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.6<f2 / f<-3.4; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -40<R3 / f<-8.

[0017] Further preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 4.1<f3 / f<5.2; the curvature radius R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 2<R5 / f<3.1.

[0018] Further preferably, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -2.9<f6 / f<-2.5; the curvature radius R11 of the object side surface of the sixth lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -0.5<(R11+R12) / (R11-R12)<-0.25.

[0019] Further preferably, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.3<f7 / f<2.5; the curvature radius R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8<R14 / f<-0.8.

[0020] Further preferably, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: -6.6<f8 / f<-2.

[0021] Further preferably, the clear half aperture CSD11 of the object side surface of the first lens and the clear half aperture CSD81 of the object side surface of the eighth lens satisfy: 2.2<CSD11 / CSD81<3.

[0022] Further preferably, the sag height SAG11 of the clear half aperture of the object side surface of the first lens and the central thickness CT1 of the first lens satisfy: 1.2<SAG11 / CT1<2.9.

[0023] Compared with existing technologies, the optical lens provided by this invention uses eight lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as ultra-wide angle, high pixel count, large aperture, low distortion, and high imaging quality. Attached Figure Description

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0040] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0041] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this 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.

[0042] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0043] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0044] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity 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 location of the concaveness 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 subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0045] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0046] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0047] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] The optical lens provided in this embodiment of the invention has eight lenses with optical power, and the optical lens includes, in sequence along the optical axis from the object side to the imaging plane: 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.

[0049] In some embodiments, the first lens may have negative optical power, with a convex object-side surface and a concave image-side surface. The second lens may have negative optical power, with both its object-side and image-side surfaces being concave. The third lens may have positive optical power, with a convex object-side surface and its image-side surface being either concave or convex. The fourth lens may have negative optical power, with a concave object-side surface and a convex image-side surface. The fifth lens may have positive optical power, with both its object-side and image-side surfaces being convex. The sixth lens may have negative optical power, with both its object-side and image-side surfaces being concave. The seventh lens may have positive optical power, with both its object-side and image-side surfaces being convex. The eighth lens may have negative optical power, with its object-side surface being convex near the optical axis and its image-side surface being concave.

[0050] In some embodiments, the optical lens may also include an aperture stop, which may be located between the third and fourth lenses. It is understood that the aperture stop is used to limit the amount of light entering the lens to change the brightness of the image. When the aperture stop is located between the third and fourth lenses, it facilitates the correction of aperture aberrations.

[0051] In some embodiments, the optical lens may further include an optical filter, which is disposed between the eighth lens and the imaging surface. The optical filter is configured to filter out stray light, preventing the stray light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0052] In some embodiments, the effective focal length f of the optical lens, the aperture value Fno of the optical lens and the total optical length TTL of the optical lens satisfy: 0.18<f×Fno / TTL<0.2. Meeting the above conditional expression enables the optical lens to have the characteristics of a short focal length matched with a large aperture, so that the optical lens has sufficient light intake, the optical lens has a wide-angle field of view to capture more scene information, and flexible depth of field control is used to enhance the layering of the image, which is beneficial to making the captured image clearer. Meanwhile, the limitation on the total optical length enables the optical lens to also meet the miniaturization requirement.

[0053] In some embodiments, the combined focal length f123 of the first lens, the second lens and the third lens and the effective focal length f of the optical lens satisfy: -3<f123 / f<-2.3. Meeting the above conditional expression, the front lens group composed of the first lens to the third lens is designed to have negative optical power, so that the optical lens can receive light rays of a large-angle field of view, and facilitates the large-angle light beam to pass through the diaphragm, so as to meet the ultra-wide-angle requirement of the optical lens. At the same time, it also helps to improve the brightness of the edge field of view on the imaging surface, thereby improving the imaging definition at the edge field of view.

[0054] In some embodiments, the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 1.45<f45678 / f<1.65. Meeting the above conditional expression is beneficial to correcting chromatic aberration and field curvature of the optical lens, reducing the deflection angle of light, lowering sensitivity, reducing the difficulty of lens molding, and achieving the balance of overall spherical aberration, so as to obtain good imaging quality of the axial field of view.

[0055] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.6<f2 / f<-3.4. Meeting the above conditional expression enables the second lens to have a negative focal length, ensures that the light beam entering the second lens diverges, makes the light of the large field of view rise slowly, is beneficial to realizing a large aperture and a large target surface, and at the same time facilitates a gentle light trend, reduces the generation of aberrations, and is beneficial to achieving high imaging quality.

[0056] In some embodiments, the radius of curvature R3 of the object-side surface of the second lens and the effective focal length f of the optical lens satisfy: -40<R3 / f<-8. Meeting the above conditional expression, by reasonably setting the object-side surface of the second lens as a concave surface, it is beneficial to converge light while reducing the deflection angle of the light, shortening the distance for the light to reach the next lens, and is beneficial to reducing the total length of the lens.

[0057] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 4.1<f3 / f<5.2. By satisfying the above conditional expression, arranging the third lens with positive optical power and defining the ratio of the focal length of the third lens to the effective focal length of the optical lens is beneficial to adjust the trend of light rays from the first lens and the second lens, so that the optical lens has the characteristics of a certain large field of view angle, low sensitivity and miniaturization.

[0058] In some embodiments, the curvature radius R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 2<R5 / f<3.1. Satisfying the above conditional expression, such arrangement makes the shape of the object side surface of the third lens a convex surface, so that the light rays passing through the second lens are converged into the third lens, which can reduce the size of the subsequent lenses, contribute to the miniaturization of the optical lens, and the third lens can effectively reduce the generation of spherical aberration and astigmatism to improve the imaging quality of the optical lens.

[0059] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -2.9<f6 / f<-2.5. Satisfying the above conditional expression, the focal length value of the sixth lens is reasonably controlled, so that the light rays of a large field of view rise slowly, the parallel light trend of the light beam changes to a divergent trend, which is beneficial to controlling the back focal length of the lens, realizing a large target surface and reducing the chief ray incidence angle.

[0060] In some embodiments, the curvature radius R11 of the object side surface of the sixth lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -0.5<(R11+R12) / (R11-R12)<-0.25. Satisfying the above conditional expression, the sixth lens is designed as a biconcave shape, which ensures that the sixth lens can better diverge light rays, thereby reducing the risk of ghosting and improving the resolution capability of the system.

[0061] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.3<f7 / f<2.5. Satisfying the above conditional expression, the positive optical power provided by the seventh lens for the optical lens can better constrain the rear-end light rays, so that chromatic aberration can be effectively corrected. Meanwhile, as the lens at the rear end position in the optical lens, the seventh lens can well correct the aberration caused by the eccentricity error of each lens on the object side, that is, the eccentricity sensitivity of the optical lens can be reduced, the astigmatism generated by the eccentricity of each lens on the object side can be suppressed, so as to realize the correction of the aberration of the optical lens and improve the imaging resolution.

[0062] In some embodiments, the curvature radius R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8<R14 / f<-0.8. By satisfying the above conditional expression, the surface profile of the image side surface of the seventh lens is controlled, which effectively corrects the spherical aberration of the optical lens, reduces the influence of astigmatism on the imaging of the optical lens, and in addition can adjust the trend of light rays, so that the optical lens has a large field of view angle and an ultra-thin profile.

[0063] In some embodiments, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: -6.6<f8 / f<-2. Satisfying the above conditional expression is beneficial to expanding the width of the light beam, so that the width of the light beam with a relatively large angle is expanded after passing through the first lens to the seventh lens, thereby effectively utilizing the negative optical power of the eighth lens to make the wide light beam fully incident on the imaging surface of the optical lens, enabling the optical lens to have a wider field of view range, which is beneficial to achieving high-pixel imaging.

[0064] In some embodiments, the clear half aperture CSD11 of the object side surface of the first lens and the clear half aperture CSD81 of the object side surface of the eighth lens satisfy: 2.2<CSD11 / CSD81<3. By satisfying the above conditional expression, controlling the ratio of the clear half aperture at the object side end of the first lens to the clear half aperture at the object side end of the eighth lens can make the optical lens have a relatively small aperture size, which is convenient for being mounted on unmanned aerial vehicle equipment; at the same time, it ensures that the optical lens can collect large-angle light rays, realize large field of view angle imaging of the optical lens, increase the imaging area of the optical lens, and improve the imaging quality.

[0065] In some embodiments, the sag height SAG11 of the clear half aperture of the object side surface of the first lens and the center thickness CT1 of the first lens satisfy: 1.2<SAG11 / CT1<2.9. By satisfying the above conditional expression and controlling the ratio of the sag height of the object side surface of the first lens to the center thickness of the first lens on the optical axis, the surface profile of the object side surface can be made to tend to bend; meanwhile, a relatively large sag height is beneficial for the first lens to collect light rays of a large field of view, realize high angular resolution at the center of the optical lens, and further improve the imaging quality of the central area.

[0066] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.7<f1 / f<-3. By satisfying the above conditional expression, the first lens of the optical lens is configured as a lens with negative optical power, which can control the incident angle of light rays, expand the field of view angle range of the optical lens, and simultaneously increase the back focal length of the optical lens, so as to avoid interference between the lens and the photosensitive chip.

[0067] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -80<f4 / f<-50. By satisfying the above conditional expression, and arranging the fourth lens with negative refractive power, it can be ensured that large-angle light enters the optical lens, the wide-angle property of the optical lens is achieved, and the brightness of the image plane in the large-angle field of view is improved.

[0068] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 1.4<f5 / f<1.8. By satisfying the above conditional expression, the propagation path of light is further restricted in cooperation with the fourth lens, which is beneficial to correcting the aberration generated by the light refracted by the previous lenses, and ensures the imaging quality.

[0069] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 3.6<IH / f<3.7. By satisfying the above conditional expression, the ratio of the effective focal length to the image height of the optical lens is controlled. Shortening the effective focal length can expand the field of view angle, so that the optical lens can capture a wider object-side space, and at the same time, the optical lens can be matched with a large image plane chip, so as to improve the imaging quality of the optical lens.

[0070] In some embodiments, the clear aperture half-diameter CSD22 of the image side surface of the second lens and the sag height SAG22 of the clear aperture half-diameter of the image side surface of the second lens satisfy: 4.6<CSD22 / SAG22<8. By satisfying the above conditional expression, adjusting the surface shape of the edge region of the image side surface of the second lens is beneficial to diverging the light of the marginal field of view, and can correct the off-axis aberration of the marginal field of view of the optical lens, so as to improve the imaging quality of the optical lens.

[0071] In some embodiments, the clear aperture half-diameter CSD11 of the object side surface of the first lens and the sag height SAG11 of the clear aperture half-diameter of the object side surface of the first lens satisfy: 2.9<CSD11 / SAG11<3.2. By satisfying the above conditional expression, the object side surface of the first lens is restricted, so that the optical lens meets the design requirement of small aperture, which is beneficial to compressing the central field of view of the optical lens, and makes the imaging quality of the marginal field of view better.

[0072] In some embodiments, the optical lens satisfies the following conditional expressions: 1.6mm<f<1.7mm; 1mm<EPD<1.2mm; 12.4mm<TTL<13.2mm; 1.49<Fno≤1.5; 31°<CRA<37°; 5.8mm<IH<6.1mm; 210°≤FOV≤215°. In the above conditional expressions, f represents the effective focal length of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, CRA represents the chief ray incident angle at the maximum image height of the optical lens, IH represents the real image height corresponding to the maximum field of view of the optical lens, and FOV represents the maximum field of view of the optical lens. By satisfying the above conditional expressions, the optical lens has at least one or more advantages among the characteristics of short focal length, ultra-large field of view, large entrance pupil diameter, short total length, large aperture, large image plane, low distortion, and low sensitivity.

[0073] In some embodiments, all eight lenses in the optical lens may adopt plastic lenses or a glass-plastic hybrid material matching structure. Preferably, the optical lens of the present invention adopts an eight-lens glass-plastic hybrid matching lens structure, which can improve thermal stability performance. Specifically, the first lens and the fifth lens may be glass lenses, and the second lens, the third lens, the fourth lens, the sixth lens, the seventh lens, and the eighth lens are all plastic lenses; the adoption of the glass-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, the first lens and the fifth lens in the optical lens provided by the present invention may be spherical lenses; the second lens, the third lens, the fourth lens, the sixth lens, the seventh lens, and the eighth lens may all be aspherical lenses.

[0075] In various embodiments of the present invention, when the lenses adopt aspherical lenses, each aspherical surface shape of the optical lens satisfies the following equation:

[0076]

[0077] Wherein, 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, H are the 4th-order, 6th-order, 8th-order, 10th-order, 12th-order, 14th-order, and 16th-order surface coefficients respectively.

[0078] The present invention will be further described below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different; for specific differences, please refer to the parameter tables of each embodiment. The following embodiments are merely 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 considered equivalent substitutions and are included within the protection scope of the present invention.

[0079] Example 1

[0080] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane S19, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter G1.

[0081] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0082] The second lens L2 has negative optical power, its object side S3 is concave, and its image side S4 is concave.

[0083] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is concave.

[0084] The fourth lens L4 has negative optical power, its object side S7 is concave, and its image side S8 is convex.

[0085] The fifth lens L5 has positive optical power, its object side S9 is convex, and its image side S10 is convex.

[0086] The sixth lens L6 has negative optical power, its object side S11 is concave, and its image side S12 is concave.

[0087] The seventh lens L7 has positive optical power, its object side S13 is convex, and its image side S14 is convex.

[0088] The eighth lens L8 has negative optical power, its object side S15 is convex near the optical axis, and its image side S16 is concave.

[0089] The object-side surface S17 and the image-side surface S18 of filter G1 are both planar.

[0090] The imaging plane S19 is a plane.

[0091] The first lens L1 and the fifth lens L5 are glass spherical lenses; the second lens L2, the third lens L3, the fourth lens L4, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are all plastic aspherical lenses.

[0092] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0093] Table 1-1

[0094]

[0095] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0096] Table 1-2

[0097]

[0098]

[0099] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown.

[0100] Figure 2 The field curvature curve of the optical lens 100 in Embodiment 1 is shown, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.05 mm to 0.1 mm, indicating that the optical lens 100 can effectively correct the field curvature.

[0101] Figure 3 The figure shows the F-Theta distortion curve of the optical lens 100 in Embodiment 1, which represents the F-Theta distortion of light at different field of view angles on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within -5% to 10%, indicating that the optical lens 100 can correct distortion well.

[0102] Figure 4The diagram shows the axial aberration curve of the optical lens 100 in Embodiment 1, 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. As can be seen from the figure, the axial aberration offset is controlled within -0.04 mm to 0.02 mm, indicating that the optical lens 100 can correct axial aberration well.

[0103] Figure 5 The diagram shows the transverse chromatic aberration curve of the optical lens 100 in Embodiment 1. It represents the chromatic aberration of each wavelength relative to the center wavelength (0.555 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the figure, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1 μm to 5 μm, indicating that the optical lens 100 can effectively correct chromatic aberration.

[0104] Example 2

[0105] Please see Figure 6 The figure shown is a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0106] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0107] Table 2-1

[0108]

[0109]

[0110] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0111] Table 2-2

[0112] S3 0.00E+00 -1.72E-02 3.49E-03 -6.45E-05 -4.05E-05 3.17E-06 2.25E-07 -2.94E-08 S4 -5.74E+00 -2.15E-02 1.37E-02 -9.83E-03 2.22E-03 1.14E-03 -6.31E-04 9.07E-05 S5 1.35E-01 4.50E-02 4.81E-03 -3.23E-03 -1.59E-03 -3.30E-04 4.09E-04 -2.41E-05 S6 1.90E+01 9.09E-02 3.51E-02 -5.82E-03 -7.37E-03 3.38E-04 5.53E-04 -2.17E-04 S7 -3.08E+01 4.05E-03 1.16E-02 4.16E-03 -2.33E-03 -3.12E-03 -1.39E-03 1.26E-03 S8 -1.25E+00 6.65E-03 -8.37E-03 -2.36E-03 6.54E-04 3.24E-04 -5.85E-04 1.29E-05 S11 -1.53E-01 -1.11E-03 4.82E-04 -4.81E-04 -1.58E-04 9.63E-07 8.50E-06 -1.09E-06 S12 -7.63E+01 2.17E-02 -7.49E-04 -1.11E-04 -8.99E-06 2.68E-06 -3.07E-06 1.04E-07 S13 -4.01E+00 7.28E-03 -1.29E-03 1.55E-04 -6.28E-05 1.62E-05 4.78E-06 -1.18E-06 S14 -2.41E+00 2.59E-03 -3.49E-03 5.87E-04 1.34E-04 -2.55E-05 -6.72E-06 1.58E-06 S15 -8.50E+00 -3.71E-02 -3.54E-03 4.43E-04 1.22E-04 -3.12E-07 -2.50E-06 1.52E-07 S16 -3.32E+00 -2.98E-02 3.65E-03 -1.73E-04 -8.36E-06 1.51E-06 -7.37E-08 -2.96E-09

[0113] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0114] from Figure 7 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.05mm to 0.1mm, indicating that the optical lens 200 can effectively correct the field curvature.

[0115] from Figure 8 As can be seen, the F-Theta distortion of the optical lens is controlled within -5% to 10%, indicating that the optical lens 200 can correct distortion well.

[0116] from Figure 9 As can be seen, the axial aberration offset is controlled within -0.06mm to 0.03mm, indicating that the optical lens 200 can effectively correct axial aberration.

[0117] from Figure 10 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -4μm to 6μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0118] Example 3

[0119] Please see Figure 11 The figure shown is a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side S6 of the third lens L3 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0120] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0121] Table 3-1

[0122]

[0123] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0124] Table 3-2

[0125]

[0126]

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

[0128] from Figure 12 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.05mm, indicating that the optical lens 300 can effectively correct the field curvature.

[0129] from Figure 13As can be seen, the F-Theta distortion of the optical lens is controlled within -5% to 10%, indicating that the optical lens 300 can correct distortion well.

[0130] from Figure 14 As can be seen, the axial aberration offset is controlled within ±0.04mm, indicating that the optical lens 300 can effectively correct axial aberration.

[0131] from Figure 15 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -4μm to 5μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0132] Please refer to Table 4 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0133] Table 4

[0134]

[0135]

[0136] In summary, the optical lens provided by the present invention adopts an eight-element glass-plastic hybrid structure. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as ultra-wide angle, high pixel count, large aperture, low distortion, and high imaging quality.

[0137] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0138] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens comprising eight lenses having optical power, characterized in that, Along the optical axis from the object side to the imaging plane, the system sequentially comprises: a first lens with negative refractive power, wherein its object side is a convex surface, and its image side is a concave surface; a second lens with negative refractive power, wherein its object side is a concave surface, and its image side is a concave surface; a third lens with positive refractive power, wherein its object side is a convex surface; a fourth lens with negative refractive power, wherein its object side is a concave surface, and its image side is a convex surface; a fifth lens with positive refractive power, wherein its object side is a convex surface, and its image side is a convex surface; a sixth lens with negative refractive power, wherein its object side is a concave surface, and its image side is a concave surface; a seventh lens with positive refractive power, wherein its object side is a convex surface, and its image side is a convex surface; an eighth lens with negative refractive power, wherein its object side is a convex surface near the optical axis, and its image side is a concave surface; wherein the effective focal length f of the optical lens, the aperture value Fno of the optical lens, and the total optical length TTL of the optical lens satisfy: 0.18<f×Fno / TTL<0.2; the combined focal length f123 of the first lens, the second lens and the third lens and the effective focal length f of the optical lens satisfy: -3<f123 / f<-2.3; the sag height SAG11 of the clear aperture on the object side of the first lens and the center thickness CT1 of the first lens satisfy: 1.2<SAG11 / CT1<2.

9.

2. The optical lens according to claim 1, characterized in that, The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -80<f4 / f<-50, and the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 1.4<f5 / f<1.

8.

3. The optical lens according to claim 1, characterized in that, The combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 1.45<f45678 / f<1.

65.

4. The optical lens according to claim 1, characterized in that, The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.6<f2 / f<-3.4; the curvature radius R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: -40<R3 / f<-8.

5. The optical lens according to claim 1, characterized in that, The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 4.1<f3 / f<5.2; the curvature radius R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: 2<R5 / f<3.

1.

6. The optical lens according to claim 1, characterized in that, The focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -2.9<f6 / f<-2.5; the curvature radius R11 of the object side of the sixth lens and the curvature radius R12 of the image side of the sixth lens satisfy: -0.5<(R11+R12) / (R11-R12)<-0.

25.

7. The optical lens according to claim 1, characterized in that, The focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.3<f7 / f<2.5; the curvature radius R14 of the image side of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8<R14 / f<-0.

8.

8. The optical lens according to claim 1, characterized in that, The focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: -6.6<f8 / f<-2.

9. The optical lens according to claim 1, characterized in that, The half-aperture CSD11 of the object-side surface of the first lens and the half-aperture CSD81 of the object-side surface of the eighth lens satisfy: 2.2 <CSD11 / CSD81<3。 10. The optical lens according to claim 1, characterized in that, The object-side half-aperture CSD11 of the first lens and the object-side half-aperture sagitta SAG11 of the first lens satisfy: 2.9 <CSD11 / SAG11<3.2。

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