Optical lens

Abstract

The application provides an optical lens, which has seven 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 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 positive optical power, whose object side surface is a convex surface and whose image side surface is a convex surface; a fifth lens with negative optical power, whose object side surface is a concave surface and whose image side surface is a concave surface; a sixth lens with negative optical power, whose image side surface is a concave surface; and a seventh lens with positive optical power, whose object side surface is a convex surface and whose image side surface is a concave surface. The optical lens provided by the application improves the imaging quality of the optical lens, reduces aberration and improves the imaging quality of the optical lens through reasonable configuration of the surface shape of each lens and reasonable matching of the optical power.

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 continuous improvement of people's requirements for driving experience, vehicle-mounted application optical lenses are increasingly used in intelligent driving, and the status of vehicle-mounted optical lenses in the automotive-related industry is continuously rising.

[0003] Advanced Driver Assistance Systems (ADAS) play an important role in intelligent driving. It collects environmental information through various lenses paired with sensors to ensure the driving safety of drivers. Surround-view lenses are used to capture the environment around the vehicle. The images captured by multiple cameras are finally transmitted to the vehicle-mounted processor for real-time processing. The processor performs appropriate correction, stitching and fusion on these images, so as to generate a continuous, seamless, all-round 360-degree surround-view image. Surround-view lenses generally adopt wide-angle lenses, which have problems such as poor imaging quality and are difficult to meet user demands. Therefore, it is necessary to develop an optical lens with good imaging effect. Contents of the Invention

[0004] In view of the above problems, the objective of the present invention is to provide an optical lens, which has the advantage of excellent imaging quality.

[0005] The present invention provides an optical lens, in which the number of lenses with optical power is seven, and the lenses sequentially include from the object side to the image plane along the optical axis: 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; 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 positive optical power, whose object side surface is a convex surface and whose image side surface is a convex surface; a fifth lens with negative optical power, whose object side surface is a concave surface and whose image side surface is a concave surface; a sixth lens with negative optical power, 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; The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 9.5<f7 / f<12.5; the curvature radius R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1.3<R13 / f<2.6; the curvature radius R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1.7<R14 / f<4.5.

[0006] Further preferably, the combined focal length f45 of the fourth lens and the fifth lens and the effective focal length f of the optical lens satisfy: 2.7<f45 / f<4.

[0007] Further preferably, the clear half-aperture d12 of the image side of the sixth lens and the clear half-aperture d13 of the object side of the seventh lens satisfy: 0.62<d12 / d13<1.

[0008] Further preferably, the radius of curvature R1 of the object side of the first lens, the radius of curvature R2 of the image side of the first lens and the center thickness CT1 of the first lens satisfy: 2.7<R1 / (R2+CT1)<4.2.

[0009] Further preferably, the center thickness CT2 of the second lens, the center thickness CT3 of the third lens and the focal length f3 of the third lens satisfy: 0.58<(CT2+CT3) / f3<1.3.

[0010] Further preferably, the sagittal height SAG7 of the clear half-aperture of the object side of the fourth lens, the sagittal height SAG8 of the clear half-aperture of the image side of the fourth lens and the center thickness CT4 of the fourth lens satisfy: -0.6<(SAG8-SAG7) / CT4<-0.35.

[0011] 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: 5<IH / EPD<7.3.

[0012] 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: 58°<f×FOV / IH<75°.

[0013] Further preferably, the radius of curvature R9 of the object side of the fifth lens and the effective focal length f of the optical lens satisfy: -1.35<R9 / f<-0.9; the radius of curvature R10 of the image side of the fifth lens and the effective focal length f of the optical lens satisfy: 3.1<R10 / f<28.

[0014] Further preferably, the radius of curvature R13 of the object side of the seventh lens and the radius of curvature R14 of the image side of the seventh lens satisfy: -0.28<(R13-R14) / (R13+R14)<-0.1.

[0015] The optical lens provided by this invention uses seven lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as miniaturization, large aperture, ultra-wide field of view, and high imaging quality. Attached Figure Description

[0016] 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.

[0017] Figure 2 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 3 This is an F-Theta distortion curve of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 4 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 5 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0021] Figure 6 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0022] Figure 7 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0023] Figure 8 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0024] Figure 9 This is the F-Theta distortion curve of the optical lens in Embodiment 2 of the present invention.

[0025] Figure 10 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0026] Figure 11 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0027] Figure 12 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0028] Figure 13 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 14 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0030] Figure 15 This is the F-Theta distortion curve of the optical lens in Embodiment 3 of the present invention.

[0031] Figure 16 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0032] Figure 17 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0033] Figure 18 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0034] Figure 19 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0035] Figure 20 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0036] Figure 21 This is the F-Theta distortion curve of the optical lens in Embodiment 4 of the present invention.

[0037] Figure 22 This is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0038] Figure 23 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0039] Figure 24 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

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

[0041] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

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

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

[0044] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

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

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

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

[0048] The optical lens provided by the embodiments of the present invention has seven lenses with optical power, and sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens along the optical axis from the object side to the imaging surface.

[0049] In some implementations, the first lens may have negative optical power, with its object side surface being convex and its image side surface being concave. The second lens may have negative optical power, with its object side surface being concave, and its image side surface may be concave or convex. The third lens may have positive optical power, with its object side surface being convex and its image side surface being convex. The fourth lens may have positive optical power, with its object side surface being convex and its image side surface being convex. The fifth lens may have negative optical power, with its object side surface being concave and its image side surface being concave. The sixth lens may have negative optical power, with its object side surface being concave or convex, and its image side surface being concave. The seventh lens may have positive optical power, with its object side surface being convex and its image side surface being concave.

[0050] In some implementations, the optical lens may further include a diaphragm, and the diaphragm may be located between the third lens and the fourth lens. It can be understood that the diaphragm is used to limit the amount of incident light so as to change the brightness of imaging. When the diaphragm is located between the third lens and the fourth lens, it is convenient to correct the diaphragm aberration.

[0051] In some implementations, the optical lens may further include an optical filter and a protective glass, and the optical filter and the protective glass may be sequentially disposed between the seventh 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. The protective glass functions to protect the optical lens, preventing the photosensitive chip from being damaged and affecting the imaging effect of the lens.

[0052] In some implementations, the fourth lens and the fifth lens may be cemented to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, further 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.

[0053] In some implementations, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 9.5<f7 / f<12.5. The seventh lens with positive optical power can further converge light, optimize imaging quality, and correct residual aberrations (such as distortion, chromatic aberration, etc.), so as to ensure imaging clarity and color reproduction.

[0054] 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: 1.3<R13 / f<2.6; 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: 1.7<R14 / f<4.5. Meeting the above ranges, by reasonably limiting the refractive power proportion and the surface shape of the seventh lens, it is beneficial to increase the divergence degree of light, enlarge the area of light entering the imaging surface, and realize large target surface imaging.

[0055] In some embodiments, the combined focal length f45 of the fourth lens and the fifth lens and the effective focal length f of the optical lens satisfy: 2.7<f45 / f<4. Meeting the above conditions helps more light enter the cemented lens smoothly, and helps improve illumination.

[0056] In some embodiments, the clear half-caliber d12 of the image-side surface of the sixth lens and the clear half-caliber d13 of the object-side surface of the seventh lens satisfy: 0.62<d12 / d13<1. Meeting the above conditions is beneficial for the lens to control light, suppress stray light, improve aberration balance, and enhance mechanical stability.

[0057] 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: 2.7<R1 / (R2+CT1)<4.2. Meeting the above ranges can reduce the difficulty of correcting distortion in the edge field of view, and control the distortion within a reasonable range.

[0058] In some embodiments, the center thickness CT2 of the second lens, the center thickness CT3 of the third lens, and the focal length f3 of the third lens satisfy: 0.58<(CT2+CT3) / f3<1.3. By reasonably setting the relationship between the center thicknesses of the second and third lenses and the focal length of the third lens, the deflection degree of light can be effectively moderated, the field curvature and distortion of the system can be effectively reduced, and the imaging quality can be improved.

[0059] In some embodiments, the clear half-caliber sag height SAG7 of the object-side surface of the fourth lens, the clear half-caliber sag height SAG8 of the image-side surface of the fourth lens, and the center thickness CT4 of the fourth lens satisfy: -0.6<(SAG8-SAG7) / CT4<-0.35. Meeting the above conditions can control the surface shape of the object-side surface of the fourth lens, which is beneficial to the manufacture and molding of the fourth lens and reduces the defective rate. In addition, it can also avoid the surface shape of this surface being too curved and complex, so that the system field curvature tends to be balanced, In some embodiments, the real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 5<IH / EPD<7.3. Meeting the above range enables the optical lens to satisfy a large image surface while ensuring sufficient image surface brightness at the edge field of view, preventing vignetting, and thus improving imaging quality.

[0060] In some embodiments, the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens, and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 58°<f×FOV / IH<75°. Meeting the above conditional expression, by reasonably limiting the relationship among the focal length, field angle and image height of the optical lens, is conducive to balancing the field 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.

[0061] In some embodiments, the curvature radius R9 of the object-side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -1.35<R9 / f<-0.9; the curvature radius R10 of the image-side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 3.1<R10 / f<28. Meeting the above range can make the fifth lens have an appropriate surface shape, which is conducive to balancing the astigmatism and field curvature of the optical lens and improving the imaging quality of the optical lens.

[0062] In some embodiments, the curvature radius R13 of the object-side surface of the seventh lens and the curvature radius R14 of the image-side surface of the seventh lens satisfy: -0.28<(R13-R14) / (R13+R14)<-0.1. Reasonably controlling the curvature radii of the object-side surface and the image-side surface of the seventh lens is thus conducive to controlling the shape of the seventh lens and correcting aberrations generated by itself.

[0063] In some embodiments, the combined focal length f13 of the first lens, the second lens and the third lens, and the combined focal length f47 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: 1.4<f13 / f47<4.5. Meeting the above range can reasonably distribute the optical power proportion of the lens groups before and after the aperture stop, increase the relative illumination of the lens, and improve the imaging quality of the lens.

[0064] In some embodiments, the combined focal length f13 of the first lens, the second lens and the third lens, and the effective focal length f of the optical lens satisfy: 4.2<f13 / f<11.5. Meeting the above requirements, by reasonably distributing the optical power of the first lens to the third lens, reduces the deflection angle of light at the front end of the lens and the generation of various off-axis aberrations.

[0065] In some embodiments, the combined focal length f47 of the fourth lens, the fifth lens, the sixth lens and the seventh lens and the effective focal length f of the optical lens satisfy: 2.3<f47 / f<3.2. Meeting the above requirements, by reasonably distributing the optical powers from the fourth lens to the seventh lens, the focal length of the optical lens is balanced, the correction capability for various aberrations at the rear end of the lens is improved, and the imaging quality of the optical lens is enhanced.

[0066] In some embodiments, the clear half aperture d1 of the object-side surface of the first lens and the clear half aperture d14 of the image-side surface of the seventh lens satisfy: 2.7<d1 / d14<4.4. By reasonably setting the ratio of the apertures of the first and last lenses, the lens can have a small head size while having a large imaging plane, which can better meet the balance of miniaturization and high pixels.

[0067] In some embodiments, the sagittal height SAG14 of the clear half aperture of the image-side surface of the seventh lens and the clear half aperture d14 of the image-side surface of the seventh lens satisfy: 0.19<SAG14 / d14<0.22. By reasonably controlling the sagittal height and aperture of the image-side surface of the seventh lens, the beam trend is controlled and the final imaging is performed, ensuring the field angle of the seventh 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.

[0068] In some embodiments, the spacing CT34 between the third lens and the fourth lens on the optical axis and the total optical length TTL of the optical lens satisfy: 0.05<CT34 / TTL<0.15. Controlling the spacing of the lens groups before and after the aperture stop helps to improve the structural compactness of the optical lens.

[0069] In some embodiments, the clear half aperture d14 of the image-side surface of the seventh lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.3<d14 / IH<0.44. Meeting the above conditions is beneficial to enlarging the exit angle of the chief ray of the marginal field of view to the imaging plane, so as to form a large imaging plane.

[0070] In some embodiments, the sagittal height SAG3 of the clear half aperture of the object-side surface of the second lens, the sagittal height SAG4 of the clear half aperture of the image-side surface of the second lens, and the center thickness CT2 of the second lens satisfy: 0.58<(SAG4-SAG3) / CT2<1.1. Meeting the above conditions can limit the central depression degree of the second lens and reduce the difficulty of aberration correction in the marginal field of view.

[0071] In some embodiments, the sag SAG13 of the clear aperture half-caliber on the object side of the seventh lens, the sag SAG14 of the clear aperture half-caliber on the image side of the seventh lens, and the center thickness CT7 of the seventh lens satisfy: -0.25<(SAG14-SAG13) / CT7<0. Satisfying the above conditions, by controlling the relationship between the sag height difference between the image side and the object side of the seventh lens and the center thickness of the seventh lens, it is beneficial to correct the coma of the off-axis field of view, and is beneficial to improving the imaging quality of the off-axis field of view of the optical lens.

[0072] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.2<TTL / f<11.5. It can effectively limit the length of the lens, which is beneficial to realizing the miniaturization of the optical lens.

[0073] In some embodiments, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.6<TTL / IH<3.7. It can better realize the miniaturization of the lens, and at the same time ensure that under the condition of the same total length of the lens, it has a larger image plane, which can match an imaging chip of a larger size to achieve high-definition imaging.

[0074] In some embodiments, the real image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens, and the maximum field angle FOV of the optical lens satisfy: -1<IH / (f×tan(FOV / 2))<-0.28. Satisfying the above conditional expressions, by reasonably limiting the relationship among the focal length, field angle and image height of the optical lens, it is beneficial to realize the balance between the field angle of the optical lens and large-target-surface imaging, and better meet the use requirements of the optical lens for high-image-quality shooting.

[0075] In some embodiments, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 90°<FOV / Fno<115°. Satisfying the above conditions is beneficial to increasing the light intake of the lens, so that the lens can perform high-definition imaging even in a dim environment.

[0076] 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: 2.7<IH / f<3.4. Satisfying the above conditions can achieve a larger field angle and imaging range, and can realize the large-image-plane characteristic 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 seventh lens to the imaging surface and the effective focal length f of the optical lens satisfy: 0.85<BL / f<1.15. Satisfying the above range is conducive to balancing between achieving good imaging quality and easy assembly, ensuring the imaging quality of the optical lens while avoiding interference between the lens and other components, and reducing the difficulty of the assembly process of the camera module.

[0078] In some embodiments, the total optical length TTL of the optical lens, the real image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.01 / °<TTL / IH / FOV<0.02 / °. Satisfying the above range can achieve a balance among large image height, long focal length and miniaturization, and improve the imaging quality of the optical lens.

[0079] In some embodiments, the sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis respectively and the total optical length TTL of the optical lens satisfy: 0.45<ΣCT / TTL<0.63. Satisfying the above conditions can effectively compress the total length of the optical lens, and is beneficial to the structural design and production process of the optical lens at the same time.

[0080] In some embodiments, the clear semi-aperture d1 of the object-side surface of the first lens, the real image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: -0.34<d1 / IH / tan(FOV / 2)<-0.13. Satisfying the above range can ensure the balance among the size of the optical lens, the field angle and the image plane.

[0081] In some embodiments, the distance BL on the optical axis from the image-side surface of the seventh lens to the imaging surface and the total optical length TTL of the optical lens satisfy: 0.1<BL / TTL<0.13. It is beneficial to realize the short back focal length of the optical lens, and is conducive to the miniaturization of the optical lens while ensuring sufficient space for the installation of optical elements.

[0082] In some embodiments, the real image height IH corresponding to the maximum field angle of the optical lens and the f-number Fno of the optical lens satisfy: 2.4mm<IH / Fno<3.5mm. Satisfying the above conditions can maintain a large image plane of the optical lens while ensuring that the optical lens has a large aperture, so as to achieve a balance between large image plane and large aperture.

[0083] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -3.2<f1 / f<-2.5. Satisfying the above range can allow a wide range of light to enter the optical lens to obtain more image information, and help to control lens distortion, reduce field curvature, and improve the geometric accuracy of the imaging surface.

[0084] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -5<f2 / f<-2.6. The second lens has a negative focal length, which can perform a second adjustment on the full field-of-view light beam, a second deflection on the large field-of-view light beam, and redirect the light beam to the transition lens group, thereby facilitating the realization of a large field of view of the optical lens.

[0085] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 2.1<f3 / f<3. Meeting the above conditions can control the trend of the optical path, provide a more reasonable incident angle of light for the subsequent lenses, improve the uniformity of relative illumination, and enhance the imaging quality.

[0086] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1<f4 / f<1.4. Meeting the above conditions, the fourth lens adopts a positive focal lens with strong refractive power, which can further focus the light, adjust the chief ray angle, optimize the imaging quality, correct residual aberrations (such as distortion, chromatic aberration, etc.), and reduce the distortion of the wide-angle lens.

[0087] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.8<f5 / f<-1.1. Meeting the above conditions, the fifth lens adopts a negative focal lens with strong refractive power, which is beneficial to further increase the imaging area of the optical lens, while balancing various aberrations generated by the front group of lenses, and improving the imaging quality of the optical lens.

[0088] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -100<f6 / f<-7.2. The sixth lens meeting the above conditions can balance the optical power, control the back focal offset after high and low temperature changes, and avoid defocusing.

[0089] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 0.57<f1 / f2<1.1. By reasonably setting the focal length ratio of the first lens and the second lens, the system length can be shortened, aberrations and distortion of the edge field of view can be reduced, so that the lens has small distortion and can provide a high-definition imaging effect.

[0090] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: 1.8<f3 / f4<2.5. Meeting the above conditions, by reasonably setting the focal lengths of the third lens and the fourth lens, the convergence of light can be better realized, the distance for light to enter the next lens can be shortened, which is beneficial to the miniaturization of the optical lens.

[0091] In some embodiments, the focal length f6 of the sixth lens and the focal length f7 of the seventh lens satisfy: -9.8<f6 / f7<-0.7. By satisfying the above range and reasonably setting the focal length relationship between the sixth lens and the seventh lens, the incident angle of marginal rays can be converged, the illumination uniformity and definition at the edge of the frame can be improved, and at the same time, aberrations such as distortion can be finely corrected, so that the lens frame can obtain a high-quality, clear image without vignetting and deformation.

[0092] In some embodiments, the center thickness CT6 of the sixth lens and the center thickness CT7 of the seventh lens satisfy: 0.6<CT6 / CT7<0.95. Satisfying the above conditions can reduce the performance sensitivity of the system, while ensuring the machinability of the lenses and assembly stability, and improving the assembly yield.

[0093] In some embodiments, the curvature radius R1 of the object-side surface of the first lens and the effective focal length f of the optical lens satisfy: 7<R1 / f<11.5; the curvature radius R2 of the image-side surface of the first lens and the effective focal length f of the optical lens satisfy: 1.7<R2 / f<2.2. The first lens is a meniscus negative lens. By reasonably configuring the ratio of the curvature radii of the object-side surface and the image-side surface of the first lens to the effective focal length of the optical lens, the first lens can collect as many light rays with a large field of view angle as possible and allow the light rays to smoothly enter the subsequent system, increasing the light throughput of the optical lens and effectively expanding the field of view range of the optical lens.

[0094] In some embodiments, the curvature radius R5 of the object-side surface of the third lens and the effective focal length f of the optical lens satisfy: 1.8<R5 / f<4; the curvature radius R6 of the image-side surface of the third lens and the effective focal length f of the optical lens satisfy: -30<R6 / f<-3.2. Satisfying the above range can make the light ray trend more stable; at the same time, it can correct coma and field curvature, improve the flatness of imaging, and enhance the imaging quality of the optical lens.

[0095] In some embodiments, the curvature radius R7 of the object-side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 0.95<R7 / f<1.55; the curvature radius R8 of the image-side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -1.2<R8 / f<-0.9. Satisfying the above range can make the light ray trend more stable; at the same time, it can correct coma and field curvature, improve the flatness of imaging, and enhance the imaging quality of the optical lens.

[0096] In some embodiments, the curvature radius R9 of the object-side surface of the fifth lens and the curvature radius R10 of the image-side surface of the fifth lens satisfy: -0.34<R9 / R10<0. Satisfying the above range can give the fifth lens an appropriate surface profile, which is beneficial to balancing the astigmatism and field curvature of the optical lens, and improving the imaging quality of the optical lens.

[0097] In some embodiments, the curvature radius R13 of the object-side surface of the seventh lens and the curvature radius R14 of the image-side surface of the seventh lens satisfy: 0.55<R13 / R14<0.88. Meeting the above conditions is conducive to converging light rays, so as to adjust the trend of marginal light beams.

[0098] In some embodiments, the curvature radius R1 of the object-side surface of the first lens and the curvature radius R2 of the image-side surface of the first lens satisfy: 0.55<(R1-R2) / (R1+R2)<0.75. The surface shape of the first lens that meets the above conditions facilitates the divergence of light rays to obtain a larger field of view, can effectively eliminate aberrations, and improve the resolution capability of the optical lens.

[0099] In some embodiments, the curvature radius R9 of the object-side surface of the fifth lens and the curvature radius R10 of the image-side surface of the fifth lens satisfy: -2<(R9-R10) / (R9+R10)<-1. By making the optical system satisfy the above relational expression, the ratio of the curvature radius of the object-side surface of the fifth lens to the curvature radius of the image-side surface of the fifth lens can be reasonably configured, the shape of the fifth lens is controlled, the spherical aberration, chromatic aberration and field curvature of the optical system are comprehensively balanced, the risk of ghosting is reduced, the resolution capability of the optical system is improved, and at the same time, the processing difficulty of the fifth lens is reduced.

[0100] In some embodiments, the optical lens satisfies the conditional expressions: 1.8mm<f<2mm, 0.8mm<EPD<1.1mm, 16mm<TTL<20mm, 1.7<Fno<2.2, 38°<CRA<46°, 1.8mm<BL<2.1mm, 190°<FOV<220°, 5.5mm<IH<6mm; where f represents the effective focal length of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the f-number of the optical lens, CRA represents the chief ray incidence angle at the maximum image height of the optical lens, BL represents the distance on the optical axis from the image-side surface of the seventh lens to the imaging plane, FOV represents the maximum field of view of the optical lens, and IH represents the real image height corresponding to the maximum field of view of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention at least: has a small total optical length; has the characteristics of short focal length and wide angle, and the short-focus lens has a deep depth of field, which can maintain relatively clear in front of and behind the subject; has an ultra-large field of view, which provides a wider shooting field of view for application scenarios such as vehicle surround-view lenses, and captures more image information; has a large imaging plane, which can match chips of larger sizes to achieve high-definition imaging; has a large aperture, which can achieve high-definition imaging even in complex light environments.

[0101] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, production costs can be effectively reduced. Conversely, when the lens material is glass, the low dispersion characteristic of glass itself can effectively correct geometric chromatic aberration of the optical system. The first and third lenses in the optical lens provided by the present invention can be made of glass, the second, fourth, and fifth lenses can be made of plastic, and the sixth and seventh lenses can be made of either glass or plastic. This glass-plastic hybrid structure effectively reduces costs, corrects aberrations, reduces size, improves thermal stability, and provides a more cost-effective optical lens product.

[0102] In some embodiments, the first, second, third, fourth, fifth, sixth, and seventh 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 and third lenses of this invention are spherical lenses; the second, fourth, and fifth lenses are aspherical lenses; and the sixth and seventh lenses are either spherical or aspherical lenses.

[0103] 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, and F are the fourth, sixth, eighth, tenth, and twelfth order surface coefficients, respectively.

[0104] 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.

[0105] Example 1

[0106] Please see Figure 1The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1, and a protective glass G2.

[0107] 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 positive optical power, its object side S5 is convex, and its image side S6 is convex. The fourth lens L4 has positive optical power, its object side S7 is convex, and its image side is convex. The fifth lens L5 has negative optical power, its object side is concave, and its image side S9 is concave. The fourth lens L4 and the fifth lens L5 form a cemented lens group with positive optical power, that is, the cemented surface of the image side of the fourth lens L4 and the object side of the fifth lens L5 is S8. The sixth lens L6 has negative optical power, its object side S10 is convex, and its image side S11 is concave. The seventh lens L7 has positive optical power, its object side surface S12 is convex, and its image side surface S13 is concave. The object-side surface S14 and the image-side surface S15 of filter G1 are both planar. The object side S16 and the image side S17 of the protective glass G2 are both flat. The imaging plane S18 is a plane.

[0108] The first lens L1, the third lens L3, and the seventh lens L7 are glass spherical lenses, while the second lens L2, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are plastic aspherical lenses.

[0109] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0110] Table 1-1 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 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: Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown.

[0112] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.04 mm to 0.02 mm, indicating that the optical lens can effectively correct the field curvature.

[0113] Figure 3 The F-Theta distortion curve of Example 1 is shown, which represents the F-Theta distortion of light at different image heights on the imaging plane. The horizontal axis represents the F-Theta distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within -12% to 0, indicating that the optical lens can correct distortion well.

[0114] Figure 4 The axial aberration curve of Example 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 can correct axial aberration well.

[0115] 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 (0.546 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 ±2 μm, indicating that the optical lens can effectively correct chromatic aberration.

[0116] Figure 6 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the 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 image quality and good detail resolution.

[0117] Example 2

[0118] 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 difference between this embodiment and Embodiment 1 is that: the sixth lens L6 is a glass spherical lens; the seventh lens L7 is a plastic aspherical lens; the image side S4 of the second lens L2 is a convex surface; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0119] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0120] Table 2-1 The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0121] Table 2-2 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: Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 As shown.

[0122] from Figure 8 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.02mm, indicating that the optical lens can effectively correct the field curvature.

[0123] from Figure 9 As can be seen, the F-Theta distortion of the optical lens is controlled within -12% to 0, indicating that the optical lens can correct distortion well.

[0124] from Figure 10 As can be seen, the axial aberration offset is controlled within -0.03mm to 0.01mm, indicating that the optical lens can effectively correct axial aberration.

[0125] from Figure 11 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 2μm, indicating that the optical lens can correct chromatic aberration well.

[0126] from Figure 12 As can be seen, the MTF value of this embodiment is above 0.5 throughout the entire field of view. Within the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, indicating good imaging quality and good detail resolution.

[0127] Example 3

[0128] Please see Figure 13 The figure shows a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The difference between this embodiment and Embodiment 1 is that the object side surface S10 of the sixth lens L6 is concave; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0129] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0130] Table 3-1 The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0131] Table 3-2 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: Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 As shown.

[0132] from Figure 14 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.02mm, indicating that the optical lens can effectively correct the field curvature.

[0133] from Figure 15 As can be seen, the F-Theta distortion of the optical lens is controlled within -20% to 0, indicating that the optical lens can correct distortion well.

[0134] from Figure 16 As can be seen, the axial aberration offset is controlled within ±0.01mm, indicating that the optical lens can effectively correct axial aberration.

[0135] 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 can effectively correct chromatic aberration.

[0136] 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 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, which has good imaging quality and good detail resolution.

[0137] Example 4

[0138] Please see Figure 19 The figure shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The difference between this embodiment and Embodiment 1 is that: the sixth lens L6 is a glass spherical lens; the seventh lens L7 is a plastic aspherical lens; the fourth lens L4 and the fifth lens L5 are not cemented lens groups; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0139] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0140] Table 4-1 The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0141] Table 4-2 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: Figure 20 , Figure 21 , Figure 22 , Figure 23 , Figure 24 As shown.

[0142] from Figure 20 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.02mm, indicating that the optical lens can effectively correct the field curvature.

[0143] from Figure 21 As can be seen, the F-Theta distortion of the optical lens is controlled within -15% to 0, indicating that the optical lens can correct distortion well.

[0144] from Figure 22 As can be seen, the axial aberration offset is controlled within ±0.01mm, indicating that the optical lens can effectively correct axial aberration.

[0145] from Figure 23 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -2μm to 1μm, indicating that the optical lens can correct chromatic aberration well.

[0146] from Figure 24 As can be seen, the MTF value of this embodiment is above 0.5 throughout the entire field of view. Within the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, indicating good imaging quality and good detail resolution.

[0147] 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, true image height IH corresponding to the maximum field of view, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, distance BL from the image side of the seventh lens to the imaging plane on the optical axis, and the numerical values ​​corresponding to each conditional expression in each embodiment.

[0148] Table 5 In summary, the optical lens provided by the present invention employs seven lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as miniaturization, large aperture, ultra-wide field of view, and high imaging quality.

[0149] 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.

[0150] 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 seven lenses having optical power, characterized in that, Along the optical axis from the object side to the image plane, the system sequentially includes: a first lens with negative optical power, whose object side is a convex surface and whose image side is a concave surface; a second lens with negative optical power, whose object side is a concave surface; a third lens with positive optical power, whose object side is a convex surface and whose image side is a convex surface; a fourth lens with positive optical power, whose object side is a convex surface and whose image side is a convex surface; a fifth lens with negative optical power, whose object side is a concave surface and whose image side is a concave surface; a sixth lens with negative optical power, whose image side is a concave surface; a seventh lens with positive optical power, whose object side is a convex surface and whose image side is a concave surface; The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 9.5<f7 / f<12.5; the radius of curvature R13 of the object side of the seventh lens and the effective focal length f of the optical lens satisfy: 1.3<R13 / f<2.6; the radius of curvature R14 of the image side of the seventh lens and the effective focal length f of the optical lens satisfy: 1.7<R14 / f<4.

5.

2. The optical lens according to claim 1, characterized in that, The combined focal length f45 of the fourth lens and the fifth lens and the effective focal length f of the optical lens satisfy: 2.7<f45 / f<4.

3. The optical lens according to claim 1, characterized in that, The clear aperture half-diameter d12 of the image side of the sixth lens and the clear aperture half-diameter d13 of the object side of the seventh lens satisfy: 0.62<d12 / d13<1.

4. The optical lens according to claim 1, characterized in that, The radius of curvature R1 of the object side of the first lens, the radius of curvature R2 of the image side of the first lens, and the central thickness CT1 of the first lens satisfy: 2.7<R1 / (R2+CT1)<4.

2.

5. The optical lens according to claim 1, characterized in that, The central thickness CT2 of the second lens, the central thickness CT3 of the third lens, and the focal length f3 of the third lens satisfy: 0.58<(CT2+CT3) / f3<1.

3.

6. The optical lens according to claim 1, characterized in that, The sagittal height SAG7 at the clear aperture half-diameter of the object side of the fourth lens, the sagittal height SAG8 at the clear aperture half-diameter of the image side of the fourth lens, and the central thickness CT4 of the fourth lens satisfy: -0.6<(SAG8-SAG7) / CT4<-0.

35.

7. The optical lens according to claim 1, characterized in that, 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: 5<IH / EPD<7.

3.

8. The optical lens according to claim 1, characterized in that, 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: 58°<f×FOV / IH<75°.

9. The optical lens according to claim 1, characterized in that, The radius of curvature R9 of the object side of the fifth lens and the effective focal length f of the optical lens satisfy: -1.35<R9 / f<-0.9; the radius of curvature R10 of the image side of the fifth lens and the effective focal length f of the optical lens satisfy: 3.1<R10 / f<28.

10. The optical lens according to claim 1, characterized in that, The radius of curvature R13 of the object side of the seventh lens and the radius of curvature R14 of the image side of the seventh lens satisfy: -0.28<(R13-R14) / (R13+R14)<-0.1.

Images