Optical lens

Abstract

The application provides an optical lens, which has six 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, wherein an object side surface of the first lens is a concave surface and an image side surface of the first lens is a convex surface; a second lens with negative optical power, wherein an image side surface of the second lens is a concave surface; a third lens with negative optical power, wherein an image side surface of the third lens is a concave surface; a fourth lens with optical power, wherein an object side surface of the fourth lens is a convex surface and an image side surface of the fourth lens is a concave surface; a fifth lens with positive optical power, wherein an object side surface of the fifth lens is a convex surface and an image side surface of the fifth lens is a convex surface; and a sixth lens with positive optical power, wherein an object side surface of the sixth lens is a convex surface and an image side surface of the sixth lens is a concave surface. The optical lens provided by the application has one or more advantages such as a large aperture, a large field of view, a large image surface, small distortion and the like.

Description

Technical Field

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

[0002] With the vigorous development of automobile assisted driving and automatic driving technologies, on-board cameras play a pivotal role. A forward-looking camera can be called the core component of ADAS (Advanced Driving Assistance System). It not only undertakes the important task of distance measurement, but also can accurately identify objects and clearly distinguish road markings. For this reason, the visual algorithms required for it are extremely complex and have high technical thresholds. In order to fully utilize the performance of forward-looking cameras, developing an optical lens with excellent imaging performance has become an urgent task. Only in this way can it ensure stable and efficient operation in complex driving environments, and lay a solid foundation for the further development of automatic driving technology. Summary of the Invention

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

[0004] The technical solution adopted by the present invention is as follows: An optical lens, wherein the number of lenses with optical power is six, and sequentially comprises the following elements from the object side to the imaging plane along the optical axis: a first lens with negative optical power, the object side surface of which is a concave surface and the image side surface of which is a convex surface; a second lens with negative optical power, the image side surface of which is a concave surface; a third lens with negative optical power, the image side surface of which is a concave surface; a fourth lens with optical power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; a fifth lens with positive optical power, the object side surface of which is a convex surface and the image side surface of which is a convex surface; a sixth lens with positive optical power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; wherein, the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f456 of the fourth lens, the fifth lens and the sixth lens satisfy: -1.8 < f123 / f456 < -1.1; 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: 1.8 < IH / EPD < 2.2.

[0005] 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: 1 < f45 / f < 1.3.

[0006] Further preferably, the half-aperture d1 of the object-side surface of the first lens and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.55 <d1 / IH<0.7。

[0007] Further preferably, the image-side half-aperture sagitta SAG12 of the sixth lens and the image-side half-aperture d12 of the sixth lens satisfy: 0.15 <SAG12 / d12<0.3。

[0008] Further preferably, the distance CT12 between the first and second lenses on the optical axis, the distance CT23 between the second and third lenses on the optical axis, the distance CT34 between the third and fourth lenses on the optical axis, the distance CT45 between the fourth and fifth lenses on the optical axis, and the distance CT56 between the fifth and sixth lenses on the optical axis, together with the total optical length TTL of the optical lens, satisfy the following: 0.02 < (CT12 + CT23 + CT34 + CT45 + CT56) / TTL < 0.07.

[0009] Further preferably, the image-side half-aperture sagitta SAG4 of the second lens, the object-side half-aperture sagitta SAG3 of the second lens, and the center thickness CT2 of the second lens satisfy: 0.01<(SAG4-SAG3) / CT2<0.15.

[0010] Further preferably, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 4 <TTL / IH<4.7。

[0011] Further preferably, the distance BL between the image-side surface of the sixth lens of the optical lens and the imaging plane on the optical axis satisfies 0.45. <BL / f<0.85。

[0012] Further preferably, the sum of the center thicknesses ΣCT of the six lenses and the total optical length TTL of the optical lens satisfy the following condition: 0.72 < ΣCT / TTL < 0.9.

[0013] Further preferably, the true image height IH corresponding to the maximum field of view of the optical lens and the aperture value Fno of the optical lens satisfy: 3.2mm <IH / Fno<4mm。

[0014] The optical lens provided by this invention uses six 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 large aperture, large field of view, large image plane, and small distortion. 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 a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

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

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

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

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

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

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

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

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

[0029] Figure 15 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

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

[0031] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0032] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0033] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0034] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0035] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0036] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0037] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] This invention provides an optical lens with six 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, and a sixth lens.

[0039] In some embodiments, the first lens may have negative optical power, its object-side surface may be concave, and its image-side surface may be convex. The second lens may have negative optical power, its object-side surface may be concave or convex, and its image-side surface may be concave. The third lens may have negative optical power, its object-side surface may be convex or concave, and its image-side surface may be concave. The fourth lens may have negative or 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 convex, 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 concave.

[0040] In some embodiments, the optical lens may also include an aperture stop, which may be located between the third and fourth lenses. It is understood that the aperture stop is used to limit the amount of light entering the lens, thereby altering the brightness of the image.

[0041] In some embodiments, the optical lens may further include a filter disposed along the optical axis between the sixth lens and the imaging plane. The filter is used to filter out interfering light and prevent it from reaching the imaging plane of the optical lens and affecting normal imaging.

[0042] In some embodiments, the fourth and fifth 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.

[0043] In some embodiments, the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f456 of the fourth lens, the fifth lens and the sixth lens satisfy: -1.8<f123 / f456<-1.1; 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: 1.8<IH / EPD<2.2. Satisfying the above ranges can reasonably distribute the power proportion of the lens groups before and after the diaphragm, which is beneficial to increasing the relative illumination of the lens and improving the imaging quality of the lens. Meanwhile, while satisfying a large image surface, the optical lens can also provide sufficient image surface brightness for the edge field of view, preventing the occurrence of vignetting, thereby improving the imaging quality.

[0044] 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: 1<f45 / f<1.3. Satisfying the above range helps more light smoothly enter the cemented lens and helps improve illumination.

[0045] In some embodiments, the clear semi-aperture d1 of the object-side surface of the first lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.55<d1 / IH<0.7. Satisfying the above range can not only ensure that the lens has a large field of view, but also ensure that the overall size of the lens is moderate.

[0046] In some embodiments, the sag SAG12 of the clear semi-aperture of the image-side surface of the sixth lens and the clear semi-aperture d12 of the image-side surface of the sixth lens satisfy: 0.15<SAG12 / d12<0.3. Satisfying the above range, reasonably controlling the ratio of the sag to the aperture of the image-side surface of the sixth lens can control the trend of light beams for final imaging, ensure that the opening angle of the sixth lens is within a certain range, which is beneficial for the optical lens to achieve high resolution, and endows the optical lens with high imaging quality.

[0047] In some embodiments, the spacing CT12 between the first lens and the second lens on the optical axis, the spacing CT23 between the second lens and the third lens on the optical axis, the spacing CT34 between the third lens and the fourth lens on the optical axis, the spacing CT45 between the fourth lens and the fifth lens on the optical axis, and the spacing CT56 between the fifth lens and the sixth lens on the optical axis, and the total optical length TTL of the optical lens satisfy: 0.02<(CT12+CT23+CT34+CT45+CT56) / TTL<0.07. Satisfying the above range can reduce the size of the lens.

[0048] In some embodiments, the sag SAG4 of the image-side clear semi-aperture of the second lens, the sag SAG3 of the object-side clear semi-aperture of the second lens, and the central thickness CT2 of the second lens satisfy: 0.01<(SAG4-SAG3) / CT2<0.15. Satisfying the above range can limit the central depression degree of the second lens and reduce the difficulty of aberration correction for edge fields of view.

[0049] 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 of the optical lens satisfy: 4<TTL / IH<4.7. Satisfying the above range can better realize the miniaturization of the lens, ensure that the lens has a larger image surface under the condition of the same total length, and can match an imaging chip of a larger size to achieve high-definition imaging.

[0050] In some embodiments, the distance BL on the optical axis from the image-side surface of the sixth lens of the optical lens to the imaging surface and the effective focal length f of the optical lens satisfy: 0.45<BL / f<0.85. Satisfying the above range is beneficial to strike a balance between achieving good imaging quality and easy assembly, ensures the imaging quality of the optical lens, avoids interference between the lens and other components, and reduces the difficulty of the assembly process of the camera module.

[0051] In some embodiments, the sum of the central thicknesses of six lenses ΣCT and the total optical length TTL of the optical lens satisfy: 0.72<ΣCT / TTL<0.9. Satisfying the above range can effectively compress the total length of the optical lens, and is beneficial to the structural design and production process of the optical lens.

[0052] In some embodiments, the real image height IH corresponding to the maximum field of view of the optical lens and the aperture value Fno of the optical lens satisfy: 3.2mm<IH / Fno<4mm. Satisfying the above range, while maintaining the large image surface of the optical lens, ensures that the optical lens has a large aperture, and realizes the balance between a large image surface and a large aperture.

[0053] In some embodiments, the combined focal length f123 of the first lens, the second lens and the third lens and the effective focal length f of the optical lens satisfy: -1.6<f123 / f<-0.85. Satisfying the above range, by reasonably distributing the optical power of the first lens to the third lens, the deflection angle of light at the front end of the lens is reduced, and the generation of various off-axis aberrations is reduced.

[0054] In some embodiments, the combined focal length f456 of the fourth lens, the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 0.7<f456 / f<0.95. Satisfying the above range, by reasonably distributing the optical power of the fourth lens to the sixth lens, the focal length of the optical lens can be balanced, the various aberration correction capabilities at the rear end of the lens can be improved, and the imaging quality of the optical lens can be enhanced.

[0055] In some embodiments, the clear half-aperture d1 of the object-side surface of the first lens and the clear half-aperture d12 of the image-side surface of the sixth lens satisfy: 1.2 < d1 / d12 < 1.7. When the above range is satisfied, by reasonably setting the aperture ratio of the first lens to the last lens, the lens can have a smaller head size and a larger imaging surface at the same time, which can better meet the balance between miniaturization and high pixels.

[0056] In some embodiments, the sag SAG8 at the clear half-aperture of the image-side surface of the fourth lens, the sag SAG7 at the clear half-aperture of the object-side surface of the fourth lens, and the central thickness CT4 of the fourth lens satisfy: 0.03 < (SAG8 - SAG7) / CT4 < 0.06. When the above range is satisfied, controlling the relationship between the sag difference between the image-side surface and the object-side surface of the fourth lens and the central thickness of the fourth lens is beneficial to the manufacturing and molding of the fourth lens and reduces the defective rate. At the same time, it can also prevent the surface shape of the fourth lens from being too curved and complex, so that the field curvature of the system tends to be balanced.

[0057] In some embodiments, the sag SAG12 at the clear half-aperture of the image-side surface of the sixth lens, the sag SAG11 at the clear half-aperture of the object-side surface of the sixth lens, and the central thickness CT6 of the sixth lens satisfy: -0.05 < (SAG12 - SAG11) / CT6 < -0.02. When the above range is satisfied, controlling the relationship between the sag difference between the image-side surface and the object-side surface of the sixth lens and the central thickness of the sixth lens is beneficial to correcting the coma of off-axis fields of view, and is beneficial to improving the imaging quality of off-axis fields of view of the optical lens.

[0058] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.3 < TTL / f < 5. When the above range is satisfied, the length of the lens can be effectively limited, which is conducive to realizing the miniaturization of the optical lens.

[0059] In some embodiments, the real image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 0.7 < (IH / 2) / (f×tan(FOV / 2)) < 0.85. When the above range is satisfied, it indicates that the optical distortion of the optical lens is well controlled, the resolving power of the optical lens is improved, and a special distortion specification is achieved at the same time, ensuring that the edge field of view occupies a larger proportion in the whole imaging picture, so that the imaging at the edge of the field of view is clearer.

[0060] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 35° < FOV / Fno < 40°. When the above range is satisfied, it is beneficial to increase the light input of the lens, enabling the lens to form high-definition images even in dim environments.

[0061] In some embodiments, the actual image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 1<IH / f<1.2. Satisfying the above range can achieve a larger field of view and imaging range, realize large image surface characteristics while ensuring the depth of field of the optical lens, thereby improving the imaging quality of the optical system.

[0062] In some embodiments, the total optical length TTL of the optical lens, the actual 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: 0.05 / °<TTL / IH / FOV<0.07 / °. Satisfying the above range can achieve a balance among large image height, large field of view and miniaturization, and improve the imaging quality of the optical lens.

[0063] In some embodiments, the effective focal length f of the optical lens, the maximum field of view FOV of the optical lens, and the actual image height IH corresponding to the maximum field of view of the optical lens satisfy: 58°<f×FOV / IH<65°. Satisfying the above range, reasonably limiting the relationship among the focal length, field of view and image height of the optical lens is conducive to realizing the balance between the field of view of the optical lens and large target surface imaging, and better meets the application requirements of high image quality shooting of the optical lens.

[0064] In some embodiments, the clear half-aperture d1 of the object side surface of the first lens, the actual 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: 0.76<d1 / IH / tan(FOV / 2)<0.95. Satisfying the above range can ensure the balance among the size, field of view and image surface of the optical lens.

[0065] In some embodiments, the distance BL on the optical axis from the image side surface of the sixth lens of the optical lens to the imaging surface and the total optical length TTL of the optical lens satisfy: 0.05<BL / TTL<0.2. Satisfying the above range is conducive to realizing the short back focal length of the optical lens, and is conducive to realizing the miniaturization of the optical lens while ensuring sufficient space for installation and focusing of optical elements.

[0066] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -44<f1 / f<-4.5. Satisfying the above range, the first lens has an appropriate negative focal length, which is conducive to expanding the field of view of the optical lens.

[0067] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -4.6<f2 / f<-1.8. Satisfying the above range, the second lens adopts a negative focal lens with strong refractive power, which is conducive to further increasing the imaging area of the optical lens, balancing various aberrations generated by the front group of lenses, and improving the imaging quality of the optical lens.

[0068] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -10 < f3 / f < -1.5. When the above range is satisfied, the third lens is also a negative lens, which can further diverge light and increase the field of view angle of the imaging system.

[0069] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.8 < f5 / f < 1.1. When the above range is satisfied, the fifth lens converges the incident light from the front end, which is beneficial to correcting the aberration caused by the front lens group and the distortion of the edge field of view, so that the lens has small distortion and can provide high-definition imaging effects.

[0070] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 3.4 < f6 / f < 13.5. When the above range is satisfied, the sixth lens performs final imaging with the light beam converged by the fifth lens, ensuring that the effective focal length of the sixth lens is within a certain range, which is beneficial to achieving high imaging quality.

[0071] In some embodiments, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: 0.43 < f2 / f3 < 2.2. When the above range is satisfied, reasonably setting the focal length ratio of the second lens and the third lens can shorten the system length, reduce aberration and distortion of the edge field of view, so that the lens has small distortion and can provide high-definition imaging effects.

[0072] In some embodiments, the central thickness CT1 of the first lens and the central thickness CT2 of the second lens satisfy: 0.3 < CT1 / CT2 < 1. When the above range is satisfied, the mutual matching of the two helps to eliminate axial chromatic aberration.

[0073] In some embodiments, the central thickness CT5 of the fifth lens and the central thickness CT6 of the sixth lens satisfy: 0.33 < CT5 / CT6 < 0.7. When the above range is satisfied, the system performance sensitivity can be reduced, while ensuring the processability of the lenses and assembly stability, and improving the assembly yield.

[0074] 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: -3.4 < R1 / f < -1.7; the curvature radius R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: -4.4 < R2 / f < -2.7. When the above range is satisfied, the first lens is a meniscus lens. Reasonably limiting the shape of the first lens enables the first lens to collect as much light with large field of view as possible and allow the light to enter the rear system smoothly, increasing the light flux of the optical lens and effectively expanding the field of view range of the optical lens.

[0075] 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: -7 < R3 / f < 3.8; the radius of curvature R4 of the image-side surface of the second lens and the effective focal length f of the optical lens satisfy: 1.5 < R4 / f < 15. Satisfying the above ranges can make the propagation trend of light 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.

[0076] In some embodiments, the radius of curvature R5 of the object-side surface of the third lens and the effective focal length f of the optical lens satisfy: -4.5 < R5 / f < 0.77; the radius of curvature R6 of the image-side surface of the third lens and the effective focal length f of the optical lens satisfy: 0.53 < R6 / f < 4. Satisfying the above ranges, reasonably controlling the shape of the third lens is beneficial to optimizing the aberration balance of the lens group and improving imaging quality.

[0077] 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: 1 < R7 / f < 1.55; 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: 0.85 < R8 / f < 1.3. Satisfying the above ranges, reasonably defining the surface shape of the fourth lens is beneficial to balancing the astigmatism and field curvature of the optical lens and improving the imaging quality of the optical lens.

[0078] In some embodiments, the radius of curvature R9 of the object-side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.85 < R9 / f < 1.3; the radius of curvature R10 of the image-side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -1.15 < R10 / f < -0.9. Satisfying the above ranges, reasonably defining the surface shape of the fifth lens can balance the field curvature of the system and avoid the deterioration of edge image quality.

[0079] 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 < R11 / f < 1.6; 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: 0.85 < R12 / f < 1.75. Satisfying the above ranges, reasonably defining the surface shape of the sixth lens is beneficial to increasing the divergence degree of light, increasing the area of light entering the imaging surface, and realizing large target surface imaging.

[0080] 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: 0.8 < R11 / R12 < 1.35. Satisfying the above ranges is beneficial to suppressing the incident angle of edge field of view on the imaging surface, effectively transmitting more light beams to the imaging surface, and at the same time balancing the field curvature and spherical aberration of the optical lens, improving the imaging quality of the optical lens.

[0081] In some embodiments, the radius of curvature R1 of the object-side surface of the first lens and the radius of curvature R2 of the image-side surface of the first lens satisfy: -0.4<(R1-R2) / (R1+R2)<-0.05. Satisfying the above range can reasonably define the surface shape of the first lens, which is conducive to the divergence of light, obtaining a larger image, effectively eliminating aberration and improving the resolution capability of the optical lens.

[0082] In some embodiments, the optical lens satisfies the following conditional expressions: 5.8mm<f<6mm; 70°<FOV<70.1°; 3.1mm<EPD<3.3mm; 28mm<TTL<28.1mm; 1.7<Fno<1.9; 6.3mm<IH<6.6mm; 18.5°<CRA<22.2°; 2.7mm<BL<4.6mm. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field of view of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the real image height corresponding to the maximum field of view of the optical lens, CRA represents the incident angle of the chief ray at the maximum image height of the optical lens, and BL represents the distance from the image-side surface of the sixth lens of the optical lens to the imaging plane on the optical axis. Satisfying the above range, the optical lens has at least one or more advantages such as large aperture, large field of view, large image plane, small distortion, etc.

[0083] In some embodiments, the lens material in the optical lens provided by the present invention may be glass or plastic. When the lens is made of plastic, the production cost can be effectively reduced. When the lens is made of glass, the low dispersion property of glass itself can effectively correct the geometric chromatic aberration of the optical system. More specifically, the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens of the present invention can all be made of glass, and the all-glass structure can effectively correct the chromatic aberration of the optical lens.

[0084] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens can be spherical lenses or aspheric lenses. Compared with the spherical structure, the aspheric structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lens, and better realizing the miniaturization of the lens. More specifically, in the present invention, the first lens, the second lens, the fourth lens, the fifth lens and the sixth lens can all be spherical lenses, and the third lens can be an aspheric lens.

[0085] In various embodiments of the present invention, when an aspheric lens is adopted as the lens, the shape of each aspheric surface of the optical lens satisfies the following equation: ; 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.

[0086] 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. Example 1

[0087] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane, 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, and a filter G1.

[0088] Among them, the first lens L1 has negative optical power, its object side S1 is concave, and its image side S2 is convex. 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 convex, and its image side S6 is concave. The fourth lens L4 has negative optical power, its object side S7 is convex, and its image side is concave. The fifth lens L5 has positive optical power, its object side is convex, and its image side S9 is convex. The fourth lens L4 and the fifth lens L5 form a cemented lens group, 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 positive optical power, its object side S10 is convex, and its image side S11 is concave. The object-side surface S12 and the image-side surface S13 of the filter G1 are both planar. The imaging plane S14 is a plane.

[0089] The first lens L1, the second lens L2, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all glass spherical lenses; the third lens L3 is a glass aspherical lens.

[0090] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0091] 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.

[0092] Table 1-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 100 are respectively as follows: Figures 2 to 5 As shown.

[0093] 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 mm to 0.06 mm, indicating that the optical lens 100 can effectively correct the field curvature.

[0094] Figure 3 The F-Theta distortion curve of Embodiment 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 -15% to 0%, indicating that the optical lens 100 can effectively correct distortion.

[0095] Figure 4 The diagram shows the axial aberration curves for Example 1, which represent the aberrations of each wavelength along the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the diagram, the axial aberration offset is controlled within -0.2 mm to 0.1 mm, indicating that the optical lens 100 can effectively correct axial aberrations.

[0096] 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 -3 μm to 2 μm, indicating that the optical lens 100 can effectively correct transverse chromatic aberration. Example 2

[0097] Please see Figure 6The 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 fourth lens L4 has positive optical power; the object side S5 of the third lens L3 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0098] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0099] 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.

[0100] Table 2-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figures 7 to 10 As shown.

[0101] from Figure 7 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.04mm to 0.06mm, indicating that the optical lens 200 can effectively correct the field curvature.

[0102] from Figure 8 As can be seen, the distortion of the optical lens is controlled within -10% to 0%, indicating that the optical lens 200 can effectively correct distortion.

[0103] from Figure 9 As can be seen, the axial aberration offset is controlled within -0.05mm to 0.1mm, indicating that the optical lens 200 can correct axial aberration well.

[0104] from Figure 10 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -5μm to 3μm, indicating that the optical lens 200 can effectively correct transverse chromatic aberration. Example 3

[0105] Please see Figure 11 The figure shows 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 fourth lens L4 has positive optical power; the object side surface S3 of the second lens L2 is convex; the object side surface S5 of the third lens L3 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0106] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0107] 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.

[0108] Table 3-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 300 are respectively as follows: Figures 12 to 15 As shown.

[0109] from Figure 12 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.04mm, indicating that the optical lens 300 can effectively correct field curvature.

[0110] from Figure 13 As can be seen, the distortion of the optical lens is controlled within -10% to 0%, indicating that the optical lens 300 can effectively correct distortion.

[0111] from Figure 14 As can be seen, the axial aberration offset is controlled within 0mm~0.05mm, indicating that the optical lens 300 can correct axial aberration well.

[0112] from Figure 15 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -5μm to 3μm, indicating that the optical lens 300 can effectively correct transverse chromatic aberration.

[0113] Please refer to Table 4 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, principal ray incident angle CRA at the maximum image height, true image height IH corresponding to the maximum field of view, maximum field of view FOV, entrance pupil diameter EPD, distance BL from the image side of the sixth lens to the imaging plane on the optical axis, and the numerical values ​​corresponding to each conditional expression in each embodiment.

[0114] Table 4 In summary, the optical lens provided by the present invention employs six 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 large aperture, large field of view, large image plane, and small distortion.

[0115] 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.

[0116] 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 six lenses having optical power, characterized in that, It sequentially comprises from the object side to the imaging surface along the optical axis: a first lens with negative refractive power, the object side surface of which is a concave surface and the image side surface of which is a convex surface; a second lens with negative refractive power, the image side surface of which is a concave surface; a third lens with negative refractive power, the image side surface of which is a concave surface; a fourth lens with refractive power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; a fifth lens with positive refractive power, the object side surface of which is a convex surface and the image side surface of which is a convex surface; a sixth lens with positive refractive power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; wherein, the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f456 of the fourth lens, the fifth lens and the sixth lens satisfy: -1.8<f123 / f456<-1.1; 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: 1.8<IH / EPD<2.

2.

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: 1<f45 / f<1.

3.

3. The optical lens according to claim 1, characterized in that, the clear aperture semi-diameter d1 of the object side surface of the first lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 0.55<d1 / IH<0.

7.

4. The optical lens according to claim 1, characterized in that, the sag SAG12 of the clear aperture semi-diameter of the image side surface of the sixth lens and the clear aperture semi-diameter d12 of the image side surface of the sixth lens satisfy: 0.15<SAG12 / d12<0.

3.

5. The optical lens according to claim 1, characterized in that, the spacing CT12 between the first lens and the second lens on the optical axis, the spacing CT23 between the second lens and the third lens on the optical axis, the spacing CT34 between the third lens and the fourth lens on the optical axis, the spacing CT45 between the fourth lens and the fifth lens on the optical axis, the spacing CT56 between the fifth lens and the sixth lens on the optical axis and the total optical length TTL of the optical lens satisfy: 0.02<(CT12+CT23+CT34+CT45+CT56) / TTL<0.

07.

6. The optical lens according to claim 1, characterized in that, the sag SAG4 of the clear aperture semi-diameter of the image side surface of the second lens, the sag SAG3 of the clear aperture semi-diameter of the object side surface of the second lens and the center thickness CT2 of the second lens satisfy: 0.01<(SAG4-SAG3) / CT2<0.

15.

7. The optical lens according to claim 1, characterized in that, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 4<TTL / IH<4.

7.

8. The optical lens according to claim 1, characterized in that, the distance BL on the optical axis from the image side surface of the sixth lens of the optical lens to the imaging surface and the effective focal length f of the optical lens satisfy: 0.45<BL / f<0.

85.

9. The optical lens according to claim 1, characterized in that, the sum ΣCT of the center thicknesses of the six lenses and the total optical length TTL of the optical lens satisfy: 0.72<ΣCT / TTL<0.

9.

10. 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 aperture value Fno of the optical lens satisfy: 3.2mm<IH / Fno<4mm.

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