Optical lens

Abstract

This invention provides an optical lens comprising nine lenses of optical power, arranged sequentially along the optical axis from the object side to the imaging plane: a first lens with negative optical power, having a convex object side and a concave image side; a second lens with negative optical power, having a concave object side and a concave image side; a third lens with negative optical power, having a concave object side; a fourth lens with positive optical power, having a convex object side and a concave image side; a fifth lens with positive optical power, having a convex image side; a sixth lens with positive optical power, having a convex object side and a convex image side; a seventh lens with negative optical power, having a concave object side and a concave image side; an eighth lens with positive optical power, having a convex object side; and a ninth lens with positive optical power, having a convex object side near the optical axis and a concave image side near the optical axis.

Description

Technical Field

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

[0002] With the popularization of autonomous driving, 360° surround view and electronic rearview mirrors, the demand for high-definition wide-angle lenses for in-vehicle perception has surged. Traditional lenses currently have many shortcomings, for example, when the field of view of the lens increases, severe barrel distortion is prone to occur, and the image quality at the edge attenuates; the lens has a long size and a large volume. Therefore, developing an optical lens that is miniaturized, has a large field of view and low distortion has become an urgent demand and development trend at present. Summary of the Invention

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

[0004] The technical solution adopted in the present invention is as follows: An optical lens, in which the number of lenses with optical power is nine, sequentially arranged from the object side to the imaging surface along the optical axis comprises: 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 concave surface and whose image side surface is a concave surface; a third lens with negative optical power, whose object side surface is a concave surface; a fourth lens with positive 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 image side surface is a convex surface; a sixth lens with positive optical power, whose object side surface is a convex surface and whose image side surface is a convex surface; a seventh lens with negative optical power, whose object side surface is a concave surface and whose image side surface is a concave surface; an eighth lens with positive optical power, whose object side surface is a convex surface; a ninth lens with positive optical power, whose object side surface is a convex surface at the position near the optical axis, and whose image side surface is a concave surface at the position near the optical axis; Wherein, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -0.03<f / f3≤0; the curvature radius R17 of the object side surface of the ninth lens and the effective focal length f of the optical lens satisfy: 2.3<R17 / f<10; the curvature radius R18 of the image side surface of the ninth lens and the effective focal length f of the optical lens satisfy: 2.2<R18 / f<12.5.

[0005] Further preferably, a clear aperture half-diameter d18 of the image side of the ninth lens and a real image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.04<d18 / IH<0.07.

[0006] Further preferably, a sagittal height SAG10 of the clear aperture half-diameter of the image side of the fifth lens, a sagittal height SAG9 of the clear aperture half-diameter of the object side of the fifth lens, and a center thickness CT5 of the fifth lens satisfy: -0.5<(SAG10-SAG9) / CT5<-0.05.

[0007] Further preferably, a 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: 20<TTL / (IH / 2) / (FOV / 2)×180°<30.

[0008] Further preferably, an effective focal length f of the optical lens and a focal length f1 of the first lens satisfy: -0.15<f / f1<-0.08.

[0009] Further preferably, the effective focal length f of the optical lens and a focal length f6 of the sixth lens satisfy: 0.45<f / f6<0.65.

[0010] Further preferably, a combined focal length f12345 of the first lens, the second lens, the third lens, the fourth lens and the fifth lens, and the effective focal length f of the optical lens satisfy: 0.9<f12345 / f<1.65.

[0011] Further preferably, a curvature radius R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: -140<R3 / f<-75; a curvature radius R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: 3.3<R4 / f<4.5.

[0012] Further preferably, a curvature radius R11 of the object side of the sixth lens and a curvature radius R12 of the image side of the sixth lens satisfy: -3<R11 / R12<-0.5; a curvature radius R13 of the object side of the seventh lens and a curvature radius R14 of the image side of the seventh lens satisfy: -1.4<R13 / R14<-0.6.

[0013] Further preferably, the curvature radius R3 of the object side of the second lens and the curvature radius R4 of the image side of the second lens satisfy: 1<(R3-R4) / (R3+R4)<1.2.

[0014] The optical lens provided by this invention has 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 short focal length, large field of view, large image plane, 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 a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 6 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0021] Figure 7 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0022] Figure 8 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0023] Figure 9 This is the F-Theta distortion curve of the optical lens in Embodiment 2 of the present invention.

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

[0025] Figure 11 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0026] Figure 12 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0027] Figure 13 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0028] Figure 14 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 15 This is the F-Theta distortion curve of the optical lens in Embodiment 3 of the present invention.

[0030] Figure 16 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0031] Figure 17 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0032] Figure 18 This is the MTF curve of the optical lens in Embodiment 3 of the present invention.

[0033] Figure 19 This is a schematic diagram of the optical lens in Embodiment 4 of the present invention.

[0034] Figure 20 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0035] Figure 21 This is the F-Theta distortion curve of the optical lens in Embodiment 4 of the present invention.

[0036] Figure 22 This is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0037] Figure 23 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0038] Figure 24 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0039] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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 concave, and its image-side surface may be concave. The third lens may have negative optical power, its object-side surface may be concave, and its image-side surface may be either convex or concave. The fourth lens may have positive 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 either convex or concave, and its image-side surface may be convex. The sixth lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be convex. The seventh lens may have negative optical power, its object-side surface may be concave, and its image-side surface may be concave. The eighth lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be either concave or convex. 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.

[0049] In some embodiments, the optical lens may also include an aperture stop, which may be located between the fifth and sixth lenses. It is understood that the aperture stop is used to limit the amount of light entering the lens, thereby altering the brightness of the image.

[0050] In some embodiments, the optical lens may further include a filter and a protective glass, which are sequentially disposed along the optical axis between the ninth lens and the imaging plane. The filter is used to filter out interfering light, preventing it from reaching the imaging plane of the optical lens and affecting normal imaging. The protective glass protects the optical lens, preventing damage to the image sensor, and improves the lens's shock and scratch resistance, while having almost no impact on the image quality of the optical lens.

[0051] In some embodiments, the sixth and seventh lenses can be cemented together to form a cemented lens, which can effectively correct chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberrations of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0052] In some embodiments, to reduce the size of the optical lens, a non-optical-power reflective element for optical path refraction can be provided between the third and fourth lenses. This reflective element is a prism. The object-facing surface of the prism is the incident surface, and the surface facing the imaging plane is the exit surface; both the incident and exit surfaces are planes. A right-angle prism can be used. Light rays originating from the object-side direction enter the prism from the incident surface, are reflected by the reflective surface, and then exit from the exit surface. By bending the optical path with a prism, the thickness of the lens can be effectively shortened.

[0053] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -0.03<f / f3≤0. Meeting the above range, the third lens has negative optical power, which can reduce the beam diameter and reduce the size of the subsequent lens group.

[0054] In some embodiments, 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: 2.3<R17 / f<10; 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: 2.2<R18 / f<12.5. Meeting the above range, the surface shape of the ninth lens is reasonably limited, which is beneficial to increasing the divergence degree of light rays, enlarging the area of light rays entering the imaging surface, and realizing large target surface imaging.

[0055] In some embodiments, the clear half-aperture d18 of the image-side surface of the ninth lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.04<d18 / IH<0.07. Meeting the above range is beneficial to enlarging the exit angle of the chief ray of the marginal field of view to the imaging surface, so as to realize large target surface imaging.

[0056] In some embodiments, the sagittal height SAG10 of the clear half-aperture of the image-side surface of the fifth lens, the sagittal height SAG9 of the clear half-aperture of the object-side surface of the fifth lens, and the center thickness CT5 of the fifth lens satisfy: -0.5<(SAG10-SAG9) / CT5<-0.05. Meeting the above range can control the surface shape of the fifth lens, facilitate the manufacture and molding of the fifth lens, and reduce the defective rate. In addition, it can also avoid the surface shape being too curved and complex, so that the system field curvature tends to be balanced.

[0057] In some embodiments, 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: 20<TTL / (IH / 2) / (FOV / 2)×180°<30. Meeting the above range can achieve a balance between large image height, large field of view and miniaturization, and improve the imaging quality of the optical lens.

[0058] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -0.15<f / f1<-0.08. Meeting the above range, the first lens has an appropriate negative focal length, which is beneficial to enlarging the field of view of the optical lens.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0.45<f / f6<0.65. Meeting the above range, the sixth lens can further focus light rays, adjust the chief ray angle, optimize imaging quality, and correct residual aberrations such as distortion and chromatic aberration, so as to reduce the distortion of the optical lens.

[0060] In some embodiments, the combined focal length f12345 of the first lens, the second lens, the third lens, the fourth lens and the fifth lens and the effective focal length f of the optical lens satisfy: 0.9<f12345 / f<1.65. Satisfying the above range and reasonably distributing the optical power from the first lens to the fifth lens can reduce the deflection angle of light at the front end of the lens and reduce the occurrence of various off-axis aberrations.

[0061] 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: -140<R3 / f<-75; 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: 3.3<R4 / f<4.5. Satisfying the above range can make the light trend more stable, and at the same time can correct coma and field curvature, improve the flatness of imaging, and enhance the imaging quality of the optical lens.

[0062] In some embodiments, the radius of curvature R11 of the object-side surface of the sixth lens and the radius of curvature R12 of the image-side surface of the sixth lens satisfy: -3<R11 / R12<-0.5; the radius of curvature R13 of the object-side surface of the seventh lens and the radius of curvature R14 of the image-side surface of the seventh lens satisfy: -1.4<R13 / R14<-0.6. Satisfying the above range can effectively adjust the angular difference of the light entering and exiting the cemented lens, which is beneficial to achieving low distortion.

[0063] In some embodiments, the radius of curvature R3 of the object-side surface of the second lens and the radius of curvature R4 of the image-side surface of the second lens satisfy: 1<(R3-R4) / (R3+R4)<1.2. Satisfying the above range and reasonably controlling the shape of the second lens can comprehensively balance the spherical aberration, chromatic aberration and field curvature of the optical system, reduce the risk of ghosting, improve the resolution capability of the optical system, and at the same time, help reduce the processing difficulty of the second lens.

[0064] In some embodiments, the clear half-aperture d1 of the object-side surface of the first lens and the clear half-aperture d18 of the image-side surface of the ninth lens satisfy: 5<d1 / d18<9. Satisfying the above range and reasonably setting the ratio of the apertures of the first and last lenses can enable the lens to have a small head size and a large imaging surface, which can better meet the balance of miniaturization and high pixels.

[0065] In some embodiments, the sagittal height SAG18 of the clear half-aperture of the image-side surface of the ninth lens and the clear half-aperture d18 of the image-side surface of the ninth lens satisfy: -0.2<SAG18 / d18<0.2. Satisfying the above range and reasonably controlling the ratio of the sagittal height to the aperture of the image-side surface of the ninth lens can control the light beam trend and perform final imaging, ensure the opening angle of the ninth lens is within a certain range, which is beneficial for the optical lens to achieve high resolution and endow the optical lens with high imaging quality.

[0066] In some embodiments, the center thickness CT4 of the fourth lens, the center thickness CT5 of the fifth lens and the focal length f5 of the fifth lens satisfy: 0.35<(CT4+CT5) / f5<0.9. Satisfying the above range can effectively moderate the deflection degree of light, effectively reduce the field curvature and distortion of the system, and improve the imaging quality.

[0067] In some embodiments, the radius of curvature R1 of the object-side surface of the first lens, the radius of curvature R2 of the image-side surface of the first lens and the center thickness CT1 of the first lens satisfy: 2<R1 / (R2+CT1)<2.8. Satisfying the above range can reduce the difficulty of correcting the distortion of the marginal field of view, and control the distortion within a reasonable range.

[0068] In some embodiments, the sag height SAG4 of the clear aperture half-diameter on the image-side surface of the second lens, the sag height SAG3 of the clear aperture half-diameter on the object-side surface of the second lens and the center thickness CT2 of the second lens satisfy: 0.4<(SAG4-SAG3) / CT2<4. Satisfying the above range can limit the central depression degree of the second lens, and reduce the difficulty of aberration correction for the marginal field of view.

[0069] In some embodiments, the sag height SAG16 of the clear aperture half-diameter on the image-side surface of the eighth lens, the sag height SAG15 of the clear aperture half-diameter on the object-side surface of the eighth lens and the center thickness CT8 of the eighth lens satisfy: -0.3<(SAG16-SAG15) / CT8<0.03. Satisfying the above range is beneficial to correcting the coma of the off-axis field of view, and is conducive to improving the imaging quality of the off-axis field of view of the optical lens.

[0070] In some embodiments, the sag height SAG18 of the clear aperture half-diameter on the image-side surface of the ninth lens, the sag height SAG17 of the clear aperture half-diameter on the object-side surface of the ninth lens and the center thickness CT9 of the ninth lens satisfy: -0.2<(SAG18-SAG17) / CT9<0.2. Satisfying the above range facilitates the processing and forming of the ninth lens, and helps to reduce the sensitivity of the ninth lens, so as to better balance the relationship between the miniaturization of the optical lens and the relative illumination of the off-axis field of view.

[0071] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 20<TTL / f<30. Satisfying the above range can effectively limit the length of the lens, which is beneficial to realizing the miniaturization of the optical lens.

[0072] In some embodiments, 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: 6<TTL / IH<8. Satisfying the above range can better realize the miniaturization of the lens, ensure that the lens has a larger image plane under the condition of the same total length, and can match an imaging chip of a larger size to realize high-definition imaging.

[0073] 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 maximum field of view angle FOV of the optical lens satisfy: -0.35 < (IH / 2) / (f×tan(FOV / 2)) < -0.3. Satisfying the above range is beneficial to balancing the field of view angle of the optical lens and large target surface imaging, and better meets the use requirements of the optical lens for high-image-quality shooting.

[0074] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 95° < FOV / Fno < 105°. Satisfying the above range is beneficial to increasing the light intake of the lens, enabling the lens to perform high-definition imaging even in dim environments.

[0075] 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: 7 < IH / EPD < 7.5. Within the above range, while the optical lens meets the requirement of a large image plane, it can also ensure sufficient image plane brightness at the edge field of view, prevent vignetting, and thus improve imaging quality.

[0076] 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: 3.4 < IH / f < 3.6. Satisfying the above range can achieve an ultra-large field of view angle and imaging range, and can realize large image plane characteristics while ensuring the depth of field of the optical lens, thereby improving the imaging quality of the optical system.

[0077] 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: 0.85 < BL / f < 1. Satisfying the above range is conducive to achieving a balance between obtaining good imaging quality and ease of assembly, ensuring the imaging quality of the optical lens while avoiding interference between the lens and other elements, and reducing the assembly process difficulty of the camera module.

[0078] 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: 52° < f×FOV / IH < 60°. Satisfying the above range reasonably restricts the relationship among the focal length, field of view angle and image height of the optical lens, which is beneficial to balancing the large field of view angle of the optical lens and large target surface imaging.

[0079] In some embodiments, the semi-aperture d1 of the object side of the first 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: -1.2<d1 / (IH / 2) / tan(FOV / 2)<-0.7. Meeting the above range can ensure the balance among the size, field of view and image plane of the optical lens.

[0080] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -0.2<f / f2<-0.14. Within the above range, the second lens is also a negative lens, which can further diverge light rays and increase the field of view of the imaging system.

[0081] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.01<f / f4<0.2. Meeting the above range, the fourth lens converges the incident light from the front end, which is beneficial to correcting the aberrations caused by the front lens group and the distortion of the marginal field of view, so that the lens has low distortion and can provide a high-definition imaging effect.

[0082] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.15<f / f5<0.3. Meeting the above range, the fifth lens has appropriate positive optical power, which facilitates the smooth transition of light rays, balances the spherical aberration and field curvature of the fourth lens at the same time, and improves the imaging quality of the optical lens.

[0083] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -0.85<f / f7<-0.55. Meeting the above range, the seventh lens has appropriate negative optical power, which is beneficial to increasing the imaging area of the optical lens and improving the imaging quality of the optical lens.

[0084] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: 0.03<f / f8<0.15. Meeting the above range can balance the optical power, control the back focal offset after high and low temperature, and avoid defocusing.

[0085] In some embodiments, the effective focal length f of the optical lens and the focal length f9 of the ninth lens satisfy: 0≤f / f9<0.16. Meeting the above range helps to reasonably collect light, ensure the light transmission, improve the relative illumination, and increase the brightness of the optical lens at the image plane.

[0086] In some embodiments, the combined focal length f12345 of the first lens, the second lens, the third lens, the fourth lens and the fifth lens, and the combined focal length f6789 of the sixth lens, the seventh lens, the eighth lens and the ninth lens satisfy: -0.12<f12345 / f6789<0.15. When the above range is satisfied, the refractive powers of the lens groups before and after the stop cooperate with each other to achieve the purposes of correcting aberration, field curvature and distortion, and improve the imaging quality of the optical lens.

[0087] In some embodiments, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: 0≤f2 / f3<0.12. When the above range is satisfied, the system length can be shortened, the aberration and the distortion of the marginal field of view can be reduced, so that the lens has small distortion and can provide a high-definition imaging effect.

[0088] In some embodiments, the focal length f6 of the sixth lens and the focal length f7 of the seventh lens satisfy: -1.65<f6 / f7<-1.05. When the above range is satisfied, it is beneficial to the correction of chromatic aberration, and the resolution capability of the system is improved.

[0089] In some embodiments, the central thickness CT5 of the fifth lens and the central thickness CT6 of the sixth lens satisfy: 1.8<CT5 / CT6<2.6. When the above range is satisfied, the fifth lens and the sixth lens can mutually regulate and control, maintaining the miniaturization feature of the optical system.

[0090] In some embodiments, the central thickness CT7 of the seventh lens and the central thickness CT8 of the eighth lens satisfy: 0.12<CT7 / CT8<0.45. When the above range is satisfied, the performance sensitivity of the system can be reduced, while ensuring the machinability of the lenses and assembly stability, and the assembly yield is improved.

[0091] In some embodiments, the radius of curvature R1 of the object-side surface of the first lens and the effective focal length f of the optical lens satisfy: 12<R1 / f<22; the radius of curvature R2 of the image-side surface of the first lens and the effective focal length f of the optical lens satisfy: 4<R2 / f<7. When the above range is satisfied, the surface shape of the first lens is reasonably set, which can enhance the light collection capability of the first lens, so as to achieve an ultra-large field of view angle.

[0092] 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: 2.8<R7 / f<3.4; 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: 2.2<R8 / f<5.8. When the above range is satisfied, the light trend can be more stable, and at the same time, coma and field curvature can be corrected, the flatness of imaging is improved, and the imaging quality of the optical lens is enhanced.

[0093] In some embodiments, the radius of curvature R11 of the object-side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 1.5<R11 / f<5.5; the radius of curvature R12 of the image-side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -3.2<R12 / f<-1.7. Meeting the above ranges and reasonably setting the surface shape of the sixth lens is beneficial to balancing the astigmatism and field curvature of the optical lens, and improving the imaging quality of the optical lens.

[0094] In some embodiments, 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: -3.2<R13 / f<-1.7; 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: 2<R14 / f<3.3. Meeting the above ranges and reasonably controlling the shape of the seventh lens can comprehensively balance the spherical aberration, chromatic aberration and field curvature of the optical system, reduce the risk of ghosting, and improve the resolution capability of the optical system. At the same time, it is also beneficial to reduce the processing difficulty of the seventh lens.

[0095] In some embodiments, the radius of curvature R15 of the object-side surface of the eighth lens and the effective focal length f of the optical lens satisfy: 2<R15 / f<10; the radius of curvature R16 of the image-side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -80<R16 / f<17. Meeting the above ranges and reasonably limiting the surface shape of the eighth lens contributes to light focusing, and improves the clarity of imaging and the uniformity of brightness.

[0096] In some embodiments, the radius of curvature R5 of the object-side surface of the third lens and the radius of curvature R6 of the image-side surface of the third lens satisfy: -400<(R5-R6) / (R5+R6)<0. Meeting the above ranges and reasonably controlling the shape of the third lens can optimize the aberration balance of the lens group and improve the imaging quality.

[0097] In some embodiments, the radius of curvature R7 of the object-side surface of the fourth lens and the radius of curvature R8 of the image-side surface of the fourth lens satisfy: -0.3<(R7-R8) / (R7+R8)<0.15. Meeting the above ranges can make the light trend more stable, and at the same time can correct coma and field curvature, improve the flatness of imaging, and enhance the imaging quality of the optical lens.

[0098] In some embodiments, the radius of curvature R17 of the object-side surface of the ninth lens and the radius of curvature R18 of the image-side surface of the ninth lens satisfy: -0.23<(R17-R18) / (R17+R18)<0.03. Meeting the above ranges and reasonably controlling the surface shape of the ninth lens helps to control the light trend of the marginal field of view, and improves the imaging quality of the marginal field of view.

[0099] In some embodiments, the optical lens satisfies the following conditional expressions: 2.69mm<f<2.71mm; 200.1°<FOV<200.3°; 1.34mm<EPD<1.36mm; 60.2mm<TTL<75.9mm; 1.9<Fno<2.1; 9.6mm<IH<9.62mm; 30°<CRA<43.9°; 2.4mm<BL<2.6mm. In the above conditional expressions, f denotes the effective focal length of the optical lens, FOV denotes the maximum field of view 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 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 plane. By satisfying the above ranges, the optical lens has at least one or more advantages such as short focal length, large field of view, large image plane, low distortion, and compact size.

[0100] In some embodiments, the material of the lenses in the optical lens provided by the present invention may be glass or plastic. When the material of the lenses is plastic, the production cost can be effectively reduced. In addition, when the material of the lenses is glass, the chromatic aberration of the optical system can be effectively corrected by utilizing the low dispersion characteristic of glass itself. More specifically, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens of the present invention can all be made of glass. Adopting an all-glass structure can effectively correct the chromatic aberration of the optical lens, so that the optical lens has good thermal stability.

[0101] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth 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, the second lens, the third lens, the fourth lens, the sixth lens, and the seventh lens of the present invention can all be spherical lenses; the fifth lens, the eighth lens, and the ninth lens can all be aspherical lenses.

[0102] In various embodiments of the present invention, when the lenses are aspherical lenses, the shape of each aspherical surface of the optical lens satisfies the following equation: ; 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, and G are the 4th-order, 6th-order, 8th-order, 10th-order, 12th-order, and 14th-order surface coefficients respectively.

[0103] 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.

[0104] Example 1

[0105] 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 third lens L3, a prism G0, a fourth lens L4, a fifth lens L5, an aperture ST, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a filter G1, and a protective glass G2. The prism G0 can be a right-angle prism, which deflects the light incident from the third lens L3 by 90° before entering the fourth lens L4. The prism G0 in the diagram is an equivalent schematic.

[0106] 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 concave, and its image side S4 is concave. The third lens L3 has negative optical power, its object side S5 is concave, and its image side S6 is convex. The surface of prism G0 facing the object side is the incident surface S7, and the surface facing the imaging surface is the exit surface S8. Both the incident and exit surfaces are planes. Since prism G0 in the figure is an equivalent schematic diagram, the reflecting surface is not shown in the figure. The fourth lens L4 has positive 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 positive optical power, its object-side surface S13 is convex, and its image-side surface is convex. The seventh lens L7 has negative optical power, its object side is concave, 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 positive optical power, its object side S16 is convex, 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 the filter G1 are both planar. The object side S22 and the image side S23 of the protective glass G2 are both flat. The imaging plane S24 is a plane.

[0107] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the sixth lens L6, and the seventh lens L7 are all glass spherical lenses; the fifth lens L5, the eighth lens L8, and the ninth lens L9 are all glass aspherical lenses.

[0108] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0109] Table 1-1

[0110] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0111] Table 1-2

[0112] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 100 are respectively as follows: Figures 2 to 6 As shown.

[0113] 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 -0.03 mm to 0 mm, indicating that the optical lens 100 can effectively correct the field curvature.

[0114] 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 4%, indicating that the optical lens 100 can effectively correct distortion.

[0115] Figure 4The axial aberration curve of Embodiment 1 is shown, 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 -0.03 mm to 0.01 mm, indicating that the optical lens 100 can correct the axial aberration well.

[0116] Figure 5 The diagram shows the transverse chromatic aberration curves for Example 1, representing 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 diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1 μm to 2 μm, indicating that the optical lens 100 can effectively correct transverse chromatic aberration.

[0117] Figure 6 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 0.5 throughout the entire field of view. Within 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, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0118] Example 2

[0119] Please see Figure 7 The figure shows 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 image side surface S6 of the third lens L3 is concave; 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 200 in Example 2 are shown in Table 2-1.

[0121] Table 2-1

[0122] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0123] Table 2-2

[0124] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 200 are respectively as follows: Figures 8 to 12 As shown.

[0125] from Figure 8 As can be seen, the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.01mm to 0mm, indicating that the optical lens 200 can effectively correct the field curvature.

[0126] from Figure 9 As can be seen, the distortion of the optical lens is controlled within 0% to 3%, indicating that the optical lens 200 can effectively correct distortion.

[0127] from Figure 10 As can be seen, the axial aberration offset is controlled within ±0.01mm, indicating that the optical lens 200 can correct the axial aberration well.

[0128] from Figure 11 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1μm, indicating that the optical lens 200 can effectively correct transverse chromatic aberration.

[0129] from Figure 12 As can be seen, the MTF value of this embodiment is above 0.5 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, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0130] Example 3

[0131] Please see Figure 13 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 surface S17 of the eighth lens L8 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0132] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0133] Table 3-1

[0134] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0135] Table 3-2

[0136] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 300 are respectively as follows: Figures 14 to 18 As shown.

[0137] from Figure 14 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.01mm, indicating that the optical lens 300 can effectively correct field curvature.

[0138] from Figure 15 As can be seen, the distortion of the optical lens is controlled within 0% to 4%, indicating that the optical lens 300 can effectively correct distortion.

[0139] from Figure 16 As can be seen, the axial aberration offset is controlled within ±0.01mm, indicating that the optical lens 300 can effectively correct axial aberration.

[0140] from Figure 17 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1μm, indicating that the optical lens 300 can effectively correct transverse chromatic aberration.

[0141] from Figure 18 As can be seen, the MTF value of this embodiment is above 0.6 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.

[0142] Example 4

[0143] Please see Figure 19 The figure shown is a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side surface S11 of the fifth lens L5 is concave; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0144] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0145] Table 4-1

[0146] The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0147] Table 4-2

[0148] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 400 are respectively as follows: Figures 20 to 24 As shown.

[0149] from Figure 20 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.02mm to 0.01mm, indicating that the optical lens 400 can effectively correct field curvature.

[0150] from Figure 21 As can be seen, the distortion of the optical lens is controlled within 0% to 3%, indicating that the optical lens 400 can effectively correct distortion.

[0151] from Figure 22 As can be seen, the axial aberration offset is controlled within ±0.01mm, indicating that the optical lens 400 can effectively correct axial aberration.

[0152] from Figure 23 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within 0μm~2μm, indicating that the optical lens 400 can correct transverse chromatic aberration well.

[0153] from Figure 24 As can be seen, the MTF value of this embodiment is above 0.5 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, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0154] Please refer to Table 5 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.

[0155] Table 5

[0156] In summary, the optical lens provided by the present invention has 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 short focal length, large field of view, large image plane, small distortion, and miniaturization.

[0157] 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.

[0158] 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 image plane, the system sequentially comprises: a first lens with negative refractive power, whose object side surface is convex and whose image side surface is concave; a second lens with negative refractive power, whose object side surface is concave and whose image side surface is concave; a third lens with negative refractive power, whose object side surface is concave; a fourth lens with positive refractive power, whose object side surface is convex and whose image side surface is concave; a fifth lens with positive refractive power, whose image side surface is convex; a sixth lens with positive refractive power, whose object side surface is convex and whose image side surface is convex; a seventh lens with negative refractive power, whose object side surface is concave and whose image side surface is concave; an eighth lens with positive refractive power, whose object side surface is convex; a ninth lens with positive refractive power, whose object side surface is convex at the paraxial region, and whose image side surface is concave at the paraxial region; wherein the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -0.03<f / f3≤0; 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: 2.3<R17 / f<10; 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: 2.2<R18 / f<12.

5.

2. The optical lens according to claim 1, characterized in that, The semi-diameter d18 of the clear aperture of the image side surface of the ninth lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.04<d18 / IH<0.

07.

3. The optical lens according to claim 1, characterized in that, The sag height SAG10 of the clear aperture of the image side surface of the fifth lens, the sag height SAG9 of the clear aperture of the object side surface of the fifth lens, and the center thickness CT5 of the fifth lens satisfy: -0.5<(SAG10-SAG9) / CT5<-0.

05.

4. The optical lens according to claim 1, characterized in that, 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: 20<TTL / (IH / 2) / (FOV / 2)×180°<30.

5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -0.15<f / f1<-0.

08.

6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0.45<f / f6<0.

65.

7. The optical lens according to claim 1, characterized in that, The combined focal length f12345 of the first lens, the second lens, the third lens, the fourth lens and the fifth lens, and the effective focal length f of the optical lens satisfy: 0.9<f12345 / f<1.

65.

8. The optical lens according to claim 1, characterized in that, 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: -140<R3 / f<-75; 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: 3.3<R4 / f<4.

5.

9. The optical lens according to claim 1, characterized in that, The radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: -3<R11 / R12<-0.5; the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: -1.4<R13 / R14<-0.

6.

10. The optical lens according to claim 1, characterized in that, The object-side radius of curvature R3 of the second lens and the image-side radius of curvature R4 of the second lens satisfy: 1<(R3-R4) / (R3+R4)<1.2.

Images