Optical lens

Abstract

The application provides an optical lens, which has nine lenses with optical power, and sequentially comprises, along an optical axis from an object side to an imaging surface: a first lens with negative optical power, whose object side surface is a convex surface and whose image side surface is a concave surface; a second lens with negative optical power, whose object side surface is a convex surface at a near optical axis and whose image side surface is a concave surface; a third lens with positive optical power, whose object side surface is a convex surface and whose image side surface is a convex surface; a fourth lens with negative optical power, whose object side surface is a convex surface and whose image side surface is a concave surface; a fifth lens with positive optical power, whose object side surface is a convex surface and whose image side surface is a convex surface; a sixth lens with negative optical power, whose object side surface is a convex surface and whose image side surface is a concave surface; a seventh lens with positive optical power, whose object side surface is a convex surface and whose image side surface is a concave surface; an eighth lens with negative optical power, whose object side surface is a concave surface and whose image side surface is a concave surface; and a ninth lens with positive optical power, whose object side surface is a convex surface and whose image side surface is a concave surface.

Description

Technical Field

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

[0002] As shooting scenarios such as outdoor casual photography and extreme sports recording become increasingly popular, the market demand for action cameras has risen significantly, and higher requirements have also been put forward for camera lenses. At present, traditional action camera lenses have technical shortcomings: conventional lenses have a limited field of view, while most ultra-wide-angle lenses adopt a fisheye structure with severe image distortion. Existing products are difficult to balance optical performance and miniaturization requirements, and cannot adapt to the lightweight design of equipment. Therefore, developing an optical lens that combines a large field of view, low distortion and miniaturization has become an urgent need and development trend at present. Contents of the Invention

[0003] In view of the above problems, the object of the present invention is to provide an optical lens, which has the advantage of excellent imaging quality.

[0004] The technical solution adopted by the present invention is as follows: An optical lens has nine lenses with optical power, sequentially arranged from the object side to the image plane along the optical axis as follows: A first lens with negative optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; A second lens with negative optical power, wherein the object side surface thereof is convex at the position close to the optical axis, and the image side surface thereof is a concave surface; A third lens with positive optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a convex surface; A fourth lens with negative optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; A fifth lens with positive optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a convex surface; A sixth lens with negative optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; A seventh lens with positive optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; An eighth lens with negative optical power, wherein the object side surface thereof is a concave surface, and the image side surface thereof is a concave surface; A ninth lens with positive optical power, wherein the object side surface thereof is convex at the position close to the optical axis, and the image side surface thereof is concave at the position close to the optical axis; Wherein, the real image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 3.1<IH / f<4; the focal length f9 of the ninth lens and the effective focal length f of the optical lens satisfy: 15<f9 / f<19.

[0005] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 14<TTL / f<17; the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 4<TTL / IH<5.

[0006] Further preferably, the real image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 6<IH / EPD<7.5; the total optical length TTL of the optical lens, the real image height IH corresponding to the maximum field of view of the optical lens and the maximum field of view FOV of the optical lens satisfy: 13.5<180°×TTL / (IH / 2) / (FOV / 2)<18.

[0007] Further preferably, the effective focal length f of the optical lens, the maximum field of view FOV of the optical lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 50°<f×FOV / IH<65°; the real image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens and the radian value θ of the maximum half field of view of the optical lens satisfy: 0.95<(IH / 2) / (f×θ)<1.03.

[0008] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -6<f1 / f<-5; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.4<f2 / f<-2.7; the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2.7<f3 / f<3.3; the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -9.6<f4 / f<-8; the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 3<f5 / f<3.8; the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -3.3<f6 / f<-2.7; the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 3.5<f7 / f<4.3; the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: -14.5<f8 / f<-11.5.

[0009] 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: 1.4<f123 / f<1.7; the combined focal length f456789 of the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens and the effective focal length f of the optical lens satisfy: 8.5<f456789 / f<11; the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: -1.8<f12 / f<-1.5; the combined focal length f67 of the sixth lens and the seventh lens and the effective focal length f of the optical lens satisfy: -13<f67 / f<-10.

[0010] Further preferably, the combined focal length f67 of the sixth lens and the seventh lens and the focal length f7 of the seventh lens satisfy: -3.3<f67 / f7<-2.6; the curvature radius R13 of the object side of the seventh lens and the effective focal length f of the optical lens satisfy: 1.5<R13 / f<1.9; the curvature radius R14 of the image side of the seventh lens and the effective focal length f of the optical lens satisfy: 10.7<R14 / f<13.7.

[0011] Further preferably, the focal length f8 of the eighth lens and the focal length f9 of the ninth lens satisfy: -0.9<f8 / f9<-0.7; the curvature radius R16 of the image side of the eighth lens and the curvature radius R17 of the object side of the ninth lens satisfy: 11.2<R16 / R17<16.5; the curvature radius R17 of the object side of the ninth lens and the effective focal length f of the optical lens satisfy: 1.9<R17 / f<2.3; the curvature radius R18 of the image side of the ninth lens and the effective focal length f of the optical lens satisfy: 2.3<R18 / f<2.8.

[0012] Further preferably, the focal length f9 of the ninth lens and the focal length f1 of the first lens satisfy: -3.5<f9 / f1<-2.7; the clear aperture half-diameter d1 of the object side of the first lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 2.6<d1 / (IH / 2)<3.6.

[0013] Further preferably, the real image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 3.44<IH / f<3.6; the focal length f9 of the ninth lens and the effective focal length f of the optical lens satisfy: 16.47<f9 / f<17.36.

[0014] The optical lens provided by this invention uses nine lenses with optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as a large field of view, a large image plane, a large aperture, small distortion, and miniaturization. Attached Figure Description

[0015] 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: Figure 1 This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0016] Figure 2 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

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

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

[0019] Figure 5 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 6 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0021] Figure 7 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

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

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

[0024] Figure 10 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

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

[0026] Figure 12 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

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

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

[0029] Figure 15 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0030] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] This invention provides an optical lens with nine lenses having optical power, arranged sequentially along the optical axis from the object side to the imaging plane as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens.

[0039] In some embodiments, the first lens may have negative optical power, its object-side surface may be convex, and its image-side surface may be concave. The second lens may have negative optical power, its object-side surface may be convex near the optical axis, and its image-side surface may be concave. The third lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be convex. The fourth lens may have negative optical power, its object-side surface may be convex, and its image-side surface may be concave. The fifth lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be convex. The sixth lens may have negative optical power, its object-side surface may be convex, and its image-side surface may be concave. The seventh lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be concave. The eighth lens may have negative optical power, its object-side surface may be concave, and its image-side surface may be concave. The ninth lens can have positive optical power, its object side can be convex near the optical axis, and its image side can be concave near the optical axis.

[0040] In some embodiments, the optical lens may further include a stop, and the stop may be located between the third lens and the fourth lens. It can be understood that the stop is used to limit the amount of incoming light so as to change the brightness of the formed image.

[0041] In some embodiments, the optical lens may further include an optical filter, which is disposed between the ninth lens and the imaging surface along the optical axis. The optical filter is used to filter out interfering light, preventing the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0042] In some embodiments, the sixth lens and the seventh lens may be cemented to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the decentration sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby lowering the processing difficulty of the optical lens and increasing the assembly yield of the optical lens.

[0043] In some embodiments, in order to reduce the size of the optical lens, a non-power reflective element for folding the optical path may be disposed between the second lens and the third lens, and the reflective element is a prism. The surface of the prism facing the object side is an incident surface, and the surface facing the imaging surface is an exit surface, and both the incident surface and the exit surface are flat surfaces. The prism may adopt a right-angle prism, and light from the object side direction enters the prism from the incident surface, is reflected by the reflective surface, and then exits from the exit surface. By arranging the prism to bend the optical path, the thickness of the lens can be effectively shortened.

[0044] In some embodiments, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 3.1<IH / f<4. Meeting the above range is conducive to controlling the field angle of the system, suppressing optical distortion, and ensuring imaging quality. More specifically: 3.44<IH / f<3.6.

[0045] In some embodiments, the focal length f9 of the ninth lens and the effective focal length f of the optical lens satisfy: 15<f9 / f<19. Meeting the above range can further converge the light, adjust the chief ray angle, and optimize the imaging quality. More specifically: 16.47<f9 / f<17.36.

[0046] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 14<TTL / f<17; the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 4<TTL / IH<5. Meeting the above ranges can effectively limit the length of the lens, which is beneficial to realizing the miniaturization of the optical lens. At the same time, on the premise of ensuring the same total length of the lens, the lens has a large image plane, which can match an imaging chip of a larger size to achieve high-definition imaging. More specifically: 15.17<TTL / f<15.8; 4.22<TTL / IH<4.58.

[0047] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 6<IH / EPD<7.5. Meeting the above ranges can not only meet the demand for a large field-of-view detection range, but also ensure sufficient light throughput, and improve the signal receiving capability in a low-light environment. More specifically: 6.72<IH / EPD<7.01.

[0048] In some embodiments, the total optical length TTL of the optical lens, the real image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 13.5<180°×TTL / (IH / 2) / (FOV / 2)<18. Meeting the above ranges can achieve a balance between large image height, large field of view angle and miniaturization. More specifically: 14.92<180°×TTL / (IH / 2) / (FOV / 2)<16.15.

[0049] In some embodiments, the effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens, and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 50°<f×FOV / IH<65°. Meeting the above ranges reasonably limits the relationship among the focal length, field of view angle and image height of the optical lens, which is beneficial to realizing the balance between the field of view angle of the optical lens and large-target-surface imaging. More specifically: 56.8°<f×FOV / IH<59.11°.

[0050] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens, the effective focal length f of the optical lens, and the radian value θ of the maximum half field of view angle of the optical lens satisfy: 0.95<(IH / 2) / (f×θ)<1.03. Meeting the above ranges is beneficial to controlling the full-field distortion of the system, ensuring small imaging deformation from the center to the edge, regular images, and realizing the low-distortion feature of the optical lens. More specifically: 0.96<(IH / 2) / (f×θ)<1.02.

[0051] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -6<f1 / f<-5. When the above range is satisfied, the first lens has an appropriate negative focal length, which is beneficial to expanding the field of view of the optical lens. More specifically: -5.43<f1 / f<-5.34.

[0052] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.4<f2 / f<-2.7. Satisfying the above range is beneficial to distortion optimization and temperature control. More specifically: -3.09<f2 / f<-3.02.

[0053] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2.7<f3 / f<3.3. When the above range is satisfied, the incident light at the front end is converged, which is beneficial to correcting the aberration caused by the front lens group and the distortion of the marginal field of view, so that the lens has small distortion and can provide a high-definition imaging effect. More specifically: 2.96<f3 / f<3.

[0054] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -9.6<f4 / f<-8; the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 3<f5 / f<3.8; the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -3.3<f6 / f<-2.7; the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 3.5<f7 / f<4.3; the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: -14.5<f8 / f<-11.5. Satisfying the above ranges can effectively correct chromatic aberration, reduce the eccentricity sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality. More specifically: -8.82<f4 / f<-8.72; 3.37<f5 / f<3.42; -3.04<f6 / f<-2.99; 3.86<f7 / f<3.93; -13.16<f8 / f<-12.61.

[0055] 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: 1.4<f123 / f<1.7. When the above range is satisfied, the optical powers of the first lens to the third lens are reasonably distributed, which can reduce the deflection angle of the light at the front end of the lens and reduce the generation of various off-axis aberrations. More specifically: 1.52<f123 / f<1.55.

[0056] In some embodiments, the combined focal length f456789 of the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens and the effective focal length f of the optical lens satisfy: 8.5<f456789 / f<11. Meeting the above range and reasonably distributing the optical power from the fourth lens to the ninth lens can balance the focal length of the optical lens, improve the correction capability for various aberrations at the rear end of the lens, and thus enhance the imaging quality of the optical lens. More specifically: 9.65<f456789 / f<10.2.

[0057] In some embodiments, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: -1.8<f12 / f<-1.5. Meeting the above range can effectively correct off-axis aberrations and improve imaging quality. More specifically: -1.65<f12 / f<-1.62.

[0058] In some embodiments, the combined focal length f67 of the sixth lens and the seventh lens and the effective focal length f of the optical lens satisfy: -13<f67 / f<-10. Meeting the above range is beneficial to optimizing chromatic aberration and spherical aberration, and better controlling the temperature. More specifically: -11.63<f67 / f<-11.32.

[0059] In some embodiments, the combined focal length f67 of the sixth lens and the seventh lens and the focal length f7 of the seventh lens satisfy: -3.3<f67 / f7<-2.6; the radius of curvature R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1.5<R13 / f<1.9; the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 10.7<R14 / f<13.7. Meeting the above range is beneficial to realizing a large image surface while shortening the total length, and is conducive to correcting distortion and improving the overall imaging quality. More specifically: -3.01<f67 / f7<-2.91; 1.68<R13 / f<1.72; 11.87<R14 / f<12.5.

[0060] In some embodiments, the focal length f8 of the eighth lens and the focal length f9 of the ninth lens satisfy: -0.9<f8 / f9<-0.7; the radius of curvature R16 of the image-side surface of the eighth lens and the radius of curvature R17 of the object-side surface of the ninth lens satisfy: 11.2<R16 / R17<16.5; the radius of curvature R17 of the object-side surface of the ninth lens and the effective focal length f of the optical lens satisfy: 1.9<R17 / f<2.3; the radius of curvature R18 of the image-side surface of the ninth lens and the effective focal length f of the optical lens satisfy: 2.3<R18 / f<2.8. Satisfying the above ranges can effectively balance the astigmatism and coma left by the previous lenses, so that the lens has better imaging quality. More specifically: -0.81<f8 / f9<-0.74; 12.46<R16 / R17<14.97; 2.08<R17 / f<2.15; 2.5<R18 / f<2.58.

[0061] In some embodiments, the focal length f9 of the ninth lens and the focal length f1 of the first lens satisfy: -3.5<f9 / f1<-2.7. Satisfying the above ranges and reasonably controlling the ratio of the focal lengths of the first and last lenses can make the lens have a small head size while having a large imaging plane, which can better meet the balance of miniaturization and high pixels. More specifically: -3.21<f9 / f1<-3.04.

[0062] In some embodiments, the clear aperture half-diameter d1 of the object-side surface of the first lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 2.6<d1 / (IH / 2)<3.6. Satisfying the above ranges can ensure that the lens has a large field of view while keeping the overall size of the lens moderate. More specifically: 2.88<d1 / (IH / 2)<3.3.

[0063] In some embodiments, the distance BL on the optical axis from the image-side surface of the ninth lens of the optical lens to the imaging plane and the effective focal length f of the optical lens satisfy: 0.71<BL / f<0.74. Satisfying the above ranges is beneficial to achieving a balance between obtaining good imaging reception effect and easy assembly, ensuring the imaging quality of the optical lens, avoiding interference between the lens and other elements, and reducing the assembly process difficulty of the camera module.

[0064] 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: 4.5<R3 / f<5.5; the radius of curvature R4 of the image-side surface of the second lens and the effective focal length f of the optical lens satisfy: 1.3<R4 / f<1.7. Satisfying the above ranges can control the surface curvature degree of the second lens, reasonably control various aberrations generated by the second lens itself, and reduce the tolerance sensitivity of the second lens. More specifically: 4.93<R3 / f<5; 1.48<R4 / f<1.51.

[0065] In some embodiments, the radius of curvature R7 of the object-side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 9.7<R7 / f<11.8; the radius of curvature R8 of the image-side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 3.3<R8 / f<4. Meeting the above ranges and reasonably controlling the surface profile of the fourth lens is beneficial to correcting various aberrations of the optical lens, improving the relative illumination of the marginal field of view, and enhancing the imaging quality of the optical lens. More specifically: 10.7<R7 / f<10.82; 3.7<R8 / f<3.75.

[0066] In some embodiments, the optical lens satisfies the following conditional expressions: 2.3mm<f<2.8mm; 190°<FOV<220°; 1.2mm<EPD<1.4mm; 38mm<TTL<41mm; 1.8<Fno<2.1; 8.5mm<IH<9.5mm; 31°<CRA<34°; 1.8mm<BL<2mm. In the above conditional expressions, f denotes the effective focal length of the optical lens, FOV denotes the maximum field of view angle of the optical lens, EPD denotes the entrance pupil diameter of the optical lens, TTL denotes the total optical length of the optical lens, Fno denotes the f-number of the optical lens, IH denotes the real image height corresponding to the maximum field of view angle of the optical lens, CRA denotes the chief ray incident angle at the maximum image height of the optical lens, and BL denotes the distance on the optical axis from the image-side surface of the ninth lens of the optical lens to the imaging surface. Meeting the above ranges, the optical lens has at least one or more advantages such as a large field of view angle, a large image plane, a large aperture, low distortion, and miniaturization. More specifically: 2.56mm<f<2.6mm; 203°<FOV<205°; 1.31mm<EPD<1.34mm; 39.32mm<TTL<40.55mm; 1.94<Fno<1.96; 8.85mm<IH<9.31mm; 31.89°<CRA<33.51°; 1.86mm<BL<1.9mm.

[0067] In some embodiments, the material of the lenses in the optical lens provided by the present invention may be glass or plastic. When the lens is made of plastic, the production cost can be effectively reduced. In addition, when the lens is made of glass, the low dispersion characteristic of the glass itself can be used to effectively correct the chromatic aberration of magnitude of the optical system. More specifically, the first lens, the second lens, the third lens, the sixth lens, and the seventh lens of the present invention may all be made of glass; the fourth lens, the fifth lens, the eighth lens, and the ninth lens may all be made of plastic.

[0068] In some embodiments, the first, second, third, fourth, fifth, sixth, seventh, eighth, and ninth lenses can be spherical or aspherical lenses. Compared to spherical structures, aspherical structures can effectively reduce aberrations in the optical system, thereby reducing the number of lenses and their size, and better achieving lens miniaturization. More specifically, the first, sixth, and seventh lenses of this invention can all be spherical lenses; and the second, third, fourth, fifth, eighth, and ninth lenses can all be aspherical lenses.

[0069] In various embodiments of the present invention, when an aspherical lens is used, the shapes of each aspherical surface of the optical lens satisfy the following equations: ; Where z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the quadratic surface coefficient, and B, C, D, E, F, G, and H are the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order surface coefficients, respectively.

[0070] 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.

[0071] Example 1

[0072] Please see Figure 1 The diagram shows a schematic representation of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100, along the optical axis from the object side to the imaging plane, includes, in sequence: a first lens L1, a second lens L2, a prism G1, 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, a ninth lens L9, and a filter G2. The prism G1 can be a right-angle prism, which deflects the light incident from the second lens L2 by 90° before it enters the third lens L3. The prism G1 in the diagram is an equivalent schematic.

[0073] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave. The second lens L2 has negative optical power, its object side S3 is convex near the optical axis, and its image side S4 is concave. The surface of prism G1 facing the object side is the incident surface S5, and the surface facing the imaging surface is the exit surface S6. Both the incident and exit surfaces are planes. Since prism G1 in the figure is an equivalent schematic diagram, the reflecting surface is not shown in the figure. The third lens L3 has positive optical power, its object side S7 is convex, and its image side S8 is convex. The fourth lens L4 has negative optical power, its object side S9 is convex, and its image side S10 is concave. The fifth lens L5 has positive optical power, its object-side surface S11 is convex, and its image-side surface S12 is convex. The sixth lens L6 has negative optical power, its object side S13 is convex, and its image side is concave. The seventh lens L7 has positive optical power, its object side is convex, and its image side S15 is concave. The sixth lens L6 and the seventh lens L7 form a cemented lens group, that is, the cemented surface of the image side of the sixth lens L6 and the object side of the seventh lens L7 is S14. The eighth lens L8 has negative optical power, its object side S16 is concave, and its image side S17 is concave. The ninth lens L9 has positive optical power, its object side S18 is convex near the optical axis, and its image side S19 is concave near the optical axis. The object-side surface S20 and the image-side surface S21 of filter G2 are both planar. The imaging plane S22 is a plane.

[0074] The first lens L1, the sixth lens L6, and the seventh lens L7 are all glass spherical lenses; the second lens L2 and the third lens L3 are all glass aspherical lenses; the fourth lens L4, the fifth lens L5, the eighth lens L8, and the ninth lens L9 are all plastic aspherical lenses.

[0075] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0076] Table 1-1

[0077] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0078] Table 1-2

[0079] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and MTF curve of the optical lens 100 are respectively as follows: Figures 2 to 5 As shown.

[0080] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light of different wavelengths 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 ±0.06 mm, indicating that the optical lens 100 can effectively correct the field curvature.

[0081] Figure 3 The F-Theta distortion curve of Example 1 is shown, which represents the F-Theta distortion at different image heights 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 distortion of the optical lens is controlled within 0% to 5%, indicating that the optical lens 100 can effectively correct distortion.

[0082] Figure 4 The diagram shows the axial aberration curves for Example 1, which represent the aberrations of each wavelength along 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 diagram, the axial aberration offset is controlled within ±0.02 mm, indicating that the optical lens 100 can effectively correct axial aberrations.

[0083] Figure 5 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.3 throughout the entire field of view. Within the range of 0~120 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0084] Example 2

[0085] 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.

[0086] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0087] Table 2-1

[0088] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0089] Table 2-2

[0090] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and MTF curve of the optical lens 200 are respectively as follows: Figures 7 to 10 As shown.

[0091] from Figure 7 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.12mm to 0.04mm, indicating that the optical lens 200 can effectively correct the field curvature.

[0092] from Figure 8 As can be seen, the distortion of the optical lens is controlled within 0% to 5%, indicating that the optical lens 200 can effectively correct distortion.

[0093] from Figure 9 As can be seen, the axial aberration offset is controlled within -0.01mm to 0.03mm, indicating that the optical lens 200 can effectively correct axial aberration.

[0094] from Figure 10 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0~120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0095] Example 3

[0096] 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 optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0097] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0098] Table 3-1

[0099] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0100] Table 3-2

[0101] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and MTF curve of the optical lens 300 are respectively as follows: Figures 12 to 15 As shown.

[0102] from Figure 12 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.04mm to 0.08mm, indicating that the optical lens 300 can effectively correct field curvature.

[0103] from Figure 13 As can be seen, the distortion of the optical lens is controlled within ±5%, indicating that the optical lens 300 can effectively correct distortion.

[0104] from Figure 14 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens 300 can effectively correct axial aberration.

[0105] from Figure 15 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0~120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0106] 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, principal ray incident angle CRA at the maximum image height, true image height IH corresponding to the maximum field of view, maximum field of view FOV, entrance pupil diameter EPD, distance BL from the image side of the ninth lens to the imaging plane on the optical axis, and the numerical values ​​corresponding to each conditional expression in each embodiment.

[0107] Table 4

[0108] In summary, the optical lens provided by the present invention employs nine lenses with optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as a large field of view, a large image plane, a large aperture, low distortion, and miniaturization.

[0109] 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.

[0110] 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 nine 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 optical power, whose object side surface is convex and whose image side surface is concave; a second lens with negative optical power, whose object side surface is convex near the optical axis and whose image side surface is concave; a third lens with positive optical power, whose object side surface is convex and whose image side surface is convex; a fourth lens with negative optical power, whose object side surface is convex and whose image side surface is concave; a fifth lens with positive optical power, whose object side surface is convex and whose image side surface is convex; a sixth lens with negative optical power, whose object side surface is convex and whose image side surface is concave; a seventh lens with positive optical power, whose object side surface is convex and whose image side surface is concave; an eighth lens with negative optical power, whose object side surface is concave and whose image side surface is concave; a ninth lens with positive optical power, whose object side surface is convex near the optical axis and whose image side surface is concave near the optical axis; wherein the real image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 3.1<IH / f<4; the focal length f9 of the ninth lens and the effective focal length f of the optical lens satisfy: 15<f9 / f<19.

2. The optical lens according to claim 1, characterized in that, The optical lens satisfies at least one of the following conditional expressions: the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 14<TTL / f<17; the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 4<TTL / IH<5.

3. The optical lens according to claim 1, characterized in that, The optical lens satisfies at least one of the following conditional expressions: the real image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 6<IH / EPD<7.5; the total optical length TTL of the optical lens, the real image height IH corresponding to the maximum field of view of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 13.5<180°×TTL / (IH / 2) / (FOV / 2)<18.

4. The optical lens according to claim 1, characterized in that, The optical lens satisfies at least one of the following conditional expressions: the effective focal length f of the optical lens, the maximum field of view FOV of the optical lens, and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 50°<f×FOV / IH<65°; the real image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens, and the radian value θ of the maximum half field of view of the optical lens satisfy: 0.95<(IH / 2) / (f×θ)<1.

03.

5. The optical lens according to claim 1, characterized in that, The optical lens satisfies at least one of the following conditional expressions, where the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -6<f1 / f<-5; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.4<f2 / f<-2.7; the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2.7<f3 / f<3.3; the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -9.6<f4 / f<-8; the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 3<f5 / f<3.8; the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -3.3<f6 / f<-2.7; the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 3.5<f7 / f<4.3; the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: -14.5<f8 / f<-11.

5.

6. The optical lens according to claim 1, characterized in that, The optical lens satisfies at least one of the following conditional expressions, where 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: 1.4<f123 / f<1.7; the combined focal length f456789 of the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens and the effective focal length f of the optical lens satisfy: 8.5<f456789 / f<11; the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: -1.8<f12 / f<-1.5; the combined focal length f67 of the sixth lens and the seventh lens and the effective focal length f of the optical lens satisfy: -13<f67 / f<-10.

7. The optical lens according to claim 1, characterized in that, The optical lens satisfies at least one of the following conditional expressions, where the combined focal length f67 of the sixth lens and the seventh lens and the focal length f7 of the seventh lens satisfy: -3.3<f67 / f7<-2.6; the radius of curvature R13 of the object-side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1.5<R13 / f<1.9; the radius of curvature R14 of the image-side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 10.7<R14 / f<13.

7.

8. The optical lens according to claim 1, characterized in that, The optical lens satisfies at least one of the following conditional expressions, where the focal length f8 of the eighth lens and the focal length f9 of the ninth lens satisfy: -0.9<f8 / f9<-0.7; the radius of curvature R16 of the image-side surface of the eighth lens and the radius of curvature R17 of the object-side surface of the ninth lens satisfy: 11.2<R16 / R17<16.5; the radius of curvature R17 of the object-side surface of the ninth lens and the effective focal length f of the optical lens satisfy: 1.9<R17 / f<2.3; the radius of curvature R18 of the image-side surface of the ninth lens and the effective focal length f of the optical lens satisfy: 2.3<R18 / f<2.

8.

9. The optical lens according to claim 1, characterized in that, The optical lens satisfies at least one of the following conditional expressions: the focal length f9 of the ninth lens and the focal length f1 of the first lens satisfy: -3.5<f9 / f1<-2.7; the clear aperture half-diameter d1 of the object side surface of the first lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 2.6<d1 / (IH / 2)<3.

6.

10. The optical lens according to claim 1, characterized in that, The optical lens satisfies at least one of the following conditional expressions: 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: 3.44<IH / f<3.6; the focal length f9 of the ninth lens and the effective focal length f of the optical lens satisfy: 16.47<f9 / f<17.36.

Images