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, 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 near the optical axis and whose image side surface is a concave surface; a third lens with positive optical power, whose image side surface is a convex surface; a fourth lens with positive optical power, whose object side surface is a concave surface and whose image side surface is a convex surface; a fifth lens with negative optical power, whose object side surface is a convex surface and whose image side surface is a concave surface near the optical axis; and a sixth lens with positive optical power, whose object side surface is a convex surface and whose image side surface is a concave surface near the optical axis. The optical lens provided by the application has one or more advantages, such as miniaturization, super wide angle, small CRA, large imaging surface, large aperture, high imaging quality and the like, through specific surface shape matching and reasonable optical power distribution.

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 in-depth integration of artificial intelligence and automation technology, intelligent lawn mowing robots are gradually replacing traditional buried-line lawn mowing equipment and becoming mainstream products in the field of courtyard maintenance. However, the current radar infrared detection lenses of commercially available lawn mowers either have too small an aperture, resulting in too dark recorded images, or too small a field of view, failing to comprehensively detect changes in the surrounding environment. Summary of the Invention

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

[0004] The technical solution adopted by the present invention is as follows: An optical lens, in which the number of lenses with optical power is six, sequentially arranged from the object side to the imaging surface along the optical axis as follows: A first lens with negative optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; A second lens with negative optical power, wherein the object side surface thereof is a concave surface at a position near the optical axis, and the image side surface thereof is a concave surface; A third lens with positive optical power, wherein the image side surface thereof is a convex surface; A fourth lens with positive optical power, wherein the object side surface thereof is a concave surface, and the image side surface thereof is a convex surface; A fifth lens with negative optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface at a position near the optical axis; A sixth lens with positive optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface at a position near the optical axis; Wherein, the real image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 2.5<IH / f<2.6; the maximum field of view FOV of the optical lens and the maximum chief ray incident angle CRA of the optical lens satisfy: 17<FOV / CRA<30.

[0005] Further preferably, the total optical length TTL of the optical lens and the aperture value Fno of the optical lens satisfy: 18mm<TTL / Fno<19mm.

[0006] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -2.7<f1 / f<-2.2; the curvature radius R1 of the object side surface of the first lens and the focal length f1 of the first lens satisfy: -3.4<R1 / f1<-2.1.

[0007] Further preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -4.5<f2 / f<-3.5; the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 7<R4 / f<13.

[0008] Further preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2.2<f3 / f<3.6; the curvature radius R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: -2.2<R6 / f<-2.1.

[0009] Further preferably, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 5.5<f4 / f<6.5.

[0010] Further preferably, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -90<f5 / f<-75.

[0011] Further preferably, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 6.3<f6 / f<8.1.

[0012] Further preferably, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: -1.5<f12 / f<-1.2.

[0013] Further preferably, the combined focal length f3456 of the third lens, the fourth lens, the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 1.5<f3456 / f<1.8.

[0014] The optical lens provided by the present invention adopts six lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be enhanced, so that the lens has one or more advantages such as ultra-wide angle, large aperture, miniaturization, small CRA, large image plane, and high imaging quality. Brief Description of the Drawings

[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 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0016] Figure 2 is an F-Theta distortion curve diagram of the optical lens in Embodiment 1 of the present invention.

[0017] Figure 3This is a field curvature curve diagram 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 the F-Theta distortion curve of the optical lens in Embodiment 2 of the present invention.

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

[0023] Figure 9 This is 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 the F-Theta distortion curve of the optical lens in Embodiment 3 of the present invention.

[0027] Figure 13 This is a field curvature curve diagram 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] The optical lens provided by the embodiments of the present invention has six lenses with optical power, which are, in order from the object side to the imaging surface along the optical axis, 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, 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 near the optical axis and its image-side surface being concave. The third lens may have positive optical power, with its object-side surface being either concave or convex, and its image-side surface being convex. The fourth lens may have positive optical power, with its object-side surface being concave and its image-side surface being convex. The fifth lens may have negative optical power, with its object-side surface being convex and its image-side surface being concave near the optical axis. The sixth lens may have positive optical power, with its object-side surface being convex and its image-side surface being concave near the optical axis.

[0040] In some embodiments, the optical lens may further include a diaphragm, which may be disposed between the second lens and the third lens. It can be understood that the diaphragm is used to limit the amount of incoming light to change the brightness of imaging. When the diaphragm is located between the second lens and the third lens, it is convenient to correct the diaphragm aberration.

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

[0042] In some embodiments, the real image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 2.5<IH / f<2.6. Satisfying the above conditional expression, the ratio of the effective focal length to the image height of the optical lens is controlled. Shortening the effective focal length can expand the field of view, enabling the optical lens to capture a wider space on the object side, increasing the width of the light beam entering the optical lens, so that the brightness of the optical lens at the image plane is improved to avoid vignetting; at the same time, the optical lens is provided with large image plane characteristics, which matches a large image plane chip to improve the resolution and ensure the imaging quality of the optical lens.

[0043] In some embodiments, the maximum field of view FOV of the optical lens and the maximum chief ray incident angle CRA of the optical lens satisfy: 17<FOV / CRA<30. Satisfying the above conditional expression enables incident light rays of different field angles of the optical lens to enter the image sensor at an appropriate angle, thereby improving the photosensitive performance of the image sensor and enhancing the imaging quality of the optical lens.

[0044] In some embodiments, the total optical length TTL of the optical lens and the aperture value Fno of the optical lens satisfy: 18mm<TTL / Fno<19mm. Meeting the above conditional formula, by controlling the relationship between the total length of the optical lens and the aperture value, it is ensured that the optical lens can meet the design requirements of large aperture and miniaturization, so that the optical lens can obtain sufficient light flux even in a dim environment, meeting the needs of high-quality and high-definition shooting.

[0045] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -2.7<f1 / f<-2.2. Meeting the above conditional formula, the first lens has negative refractive power, which can diverge the light rays passing through it, expand the field of view of the optical lens, and simplify the balance between the overall aberration correction and imaging quality of the optical lens.

[0046] In some embodiments, the curvature radius R1 of the object side of the first lens and the focal length f1 of the first lens satisfy: -3.4<R1 / f1<-2.1. Meeting the above conditional formula can constrain the surface shape of the object side of the first lens, which is beneficial to reduce the bending degree of light rays at the image side of the first lens, helps the incident light rays to converge, reduces the astigmatism of the optical lens, so as to balance the astigmatism problem caused by the large field of view of the optical lens, so that the astigmatism will not be too large while the optical lens has a large field of view, thereby ensuring that the optical lens has excellent imaging quality; at the same time, the curvature radius value of the object side of the first lens is relatively large, making its object side relatively gentle, preventing the object side of the first lens from being scratched.

[0047] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -4.5<f2 / f<-3.5. Meeting the above conditional formula, setting the second lens to have negative refractive power can further control the incident angle of light rays, expand the range of the field of view of the optical lens, and at the same time increase the back focal length of the optical lens to avoid interference between the lens and the photosensitive chip, and also facilitate aberration correction, which can further improve the imaging quality of the optical lens.

[0048] In some embodiments, the curvature radius R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: 7<R4 / f<13. Meeting the above conditional formula, such arrangement makes the shape of the image side of the second lens a concave surface, so that the light rays passing through the first lens are converged into the second lens, which can reduce the size of the subsequent lenses, contribute to the miniaturization of the optical lens, and the second lens can effectively reduce the generation of spherical aberration and astigmatism to improve the imaging quality of the optical lens.

[0049] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2.2<f3 / f<3.6. Satisfying the above conditional expression enables the third lens to have the function of converging light rays. When matched with the negative optical power of the first lens and the second lens, it can further converge the light rays passing through the second lens, reduce the height of peripheral light rays, which is beneficial to reducing the caliber of the rear-end lens, and at the same time facilitates balancing aberrations and improving resolution.

[0050] In some embodiments, the curvature radius R6 of the image-side surface of the third lens and the effective focal length f of the optical lens satisfy: -2.2<R6 / f<-2.1. Satisfying the above conditional expression, the image-side surface of the third lens is designed as a convex surface, which can reasonably limit the width of the light beam emitted from the third lens, while reducing the sensitivity of the optical lens and improving assembly stability.

[0051] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 5.5<f4 / f<6.5. Satisfying the above conditional expression, by providing the fourth lens with a relatively large positive optical power, it is possible to further converge the light rays from the first three lenses, correct the aberration problems caused by the first three lenses, and effectively improve the aberration of the marginal field of view, so as to enhance the overall imaging quality of the optical lens.

[0052] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -90<f5 / f<-75. Satisfying the above conditional expression, the fifth lens is set to have negative optical power, so that the light rays of a large field of view rise slowly, changing the parallel light trend of the light beam to a divergent trend, which is beneficial to controlling the back focal length of the lens and realizing a large target surface.

[0053] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 6.3<f6 / f<8.1. Satisfying the above conditional expression, the positive optical power provided by the sixth lens for the optical lens can better constrain the rear-end light rays, thereby effectively correcting chromatic aberration. At the same time, the seventh lens, as the lens at the rear end position in the optical lens, can better correct the aberrations generated by the eccentricity errors of the object-side lenses, that is, it can reduce the eccentricity sensitivity of the optical lens, suppress the astigmatism generated by the eccentricity of the object-side lenses, so as to realize the correction of the aberrations of the optical lens and improve the imaging resolution.

[0054] In some embodiments, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: -1.5<f12 / f<-1.2. Satisfying the above conditional expression, the front lens group composed of the first lens and the second lens is designed to have negative optical power, so that the optical lens can receive light rays with a large field of view angle, and is beneficial for large-angle light beams to pass through the aperture stop, so as to meet the ultra-wide-angle requirement of the optical lens, and at the same time help to improve the brightness of the edge field of view on the imaging surface, thereby improving the imaging definition at the edge field of view.

[0055] In some embodiments, the combined focal length f3456 of the third lens, the fourth lens, the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 1.5<f3456 / f<1.8. Satisfying the above conditional expression, the rear lens group composed of the third lens to the sixth lens is designed to have positive optical power, which is beneficial to correct the chromatic aberration and field curvature of the optical lens, reduce the deflection angle of light rays, lower the sensitivity, reduce the difficulty of lens molding, and can achieve the balance of the overall spherical aberration, so as to obtain good imaging quality of the on-axis field of view.

[0056] In some embodiments, the clear semi-aperture CSD11 on the object side of the first lens and the clear semi-aperture CSD61 on the object side of the sixth lens satisfy: 1.5<CSD11 / CSD61<1.8. Satisfying the above conditional expression, by controlling the ratio of the clear semi-aperture at the object side end of the first lens to the clear semi-aperture at the object side end of the sixth lens, the optical lens can have a smaller aperture size to meet the small-head design; at the same time, it is ensured that the optical lens can collect large-angle light rays, realize large field-of-view angle imaging of the optical lens, increase the imaging area of the optical lens, and improve the imaging quality.

[0057] In some embodiments, the sag SAG11 of the clear semi-aperture on the object side of the first lens and the center thickness CT1 of the first lens satisfy: 0.5<SAG11 / CT1<0.9. Satisfying the above conditional expression, controlling the ratio of the sag of the object side of the first lens to the center thickness of the first lens on the optical axis can make the surface profile of the object side tend to be curved, and the relatively large sag is beneficial for the first lens to collect light rays of a large field of view, realize high angular resolution at the center of the optical lens, and further improve the imaging quality of the central area.

[0058] In some embodiments, the clear semi-aperture CSD11 on the object side of the first lens and the spacing CT12 of the first lens and the second lens on the optical axis satisfy: 3<CSD11 / CT12<3.5. Satisfying the above conditional expression, by controlling the clear aperture of the object side of the first lens and reducing the air gap between the first lens and the second lens, it is beneficial to reduce the total length of the optical lens, make the layout of the optical lens more compact, and reduce the risk of ghost image generation; furthermore, it is also beneficial to reduce the difficulty of structural layout of the optical lens, and improve the assembly and molding yield of the optical lens.

[0059] In some embodiments, the clear semi-aperture CSD32 of the image side of the third lens and the sagittal height SAG32 of the clear semi-aperture of the image side of the third lens satisfy: -3.4<CSD32 / SAG32<-3.1. Satisfying the above conditional expression, by adjusting the surface profile of the edge region of the image side of the third lens, it is beneficial to diverge the light rays of the edge field of view, and at the same time can correct the off-axis aberration of the edge field of view of the optical lens, so as to improve the imaging quality of the optical lens.

[0060] In some embodiments, the optical lens satisfies the following conditional expressions: 2.9mm<f<3.1mm; 140°<FOV<150°; 2.4mm<EPD<2.6mm; 21mm<TTL<23mm; 1.1<Fno<1.3; 4.5°<CRA<8.5°; 7.4mm<IH<7.7mm. In the above conditional expressions, f denotes the effective focal length of the optical lens, TTL denotes the total optical length of the optical lens, FOV denotes the maximum field of view angle of the optical lens, EPD denotes the entrance pupil diameter of the optical lens, Fno denotes the f-number of the optical lens, CRA denotes the chief ray incident angle at the maximum image height of the optical lens, and IH denotes the real image height corresponding to the maximum field of view angle of the optical lens. Satisfying the above conditional expressions, the optical lens has at least one or more of the following advantages: short focal length, ultra-large field of view angle, large entrance pupil diameter, short total length, large aperture, small CRA, large image plane, low distortion, and low sensitivity.

[0061] In some embodiments, the material of the lenses in the optical lens provided by the present invention may be glass or plastic. When the material of the lens is plastic, the production cost can be effectively reduced. In addition, when the material of the lens is glass, the geometric chromatic aberration of the optical system can be effectively corrected by utilizing the low dispersion characteristic of the glass itself. In the present invention, the second lens, the fourth lens, the fifth lens, and the sixth lens are made of plastic; the first lens and the third lens are made of glass.

[0062] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens may 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 lenses, and better realizing the miniaturization of the lens. More specifically, in the present invention, the second lens, the fourth lens, the fifth lens, and the sixth lens are aspheric lenses; the first lens and the third lens are spherical lenses.

[0063] In various embodiments of the present invention, when the lenses adopt aspheric lenses, each aspheric surface shape 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, F, G, and H are the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order surface coefficients, respectively.

[0064] 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.

[0065] Example 1

[0066] Please see Figure 1 The figure shown is a schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, in sequence along the optical axis from the object side to the imaging plane: a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a filter G1.

[0067] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave. The second lens L2 has negative optical power, its object side S3 is concave near the optical axis, and its image side S4 is concave. The third lens L3 has positive optical power, its object side S5 is concave, and its image side S6 is convex. The fourth lens L4 has positive optical power, its object side S7 is concave, and its image side S8 is convex. The fifth lens L5 has negative optical power, its object side S9 is convex, and its image side S10 is concave near the optical axis. The sixth lens L6 has positive optical power, its object side S11 is convex, and its image side S12 is concave near the optical axis. The object-side surface S13 and the image-side surface S14 of filter G1 are both planar. The imaging plane S15 is a plane.

[0068] The first lens L1 and the third lens L3 are glass spherical lenses; the second lens L2, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are plastic aspherical lenses.

[0069] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0070] 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.

[0071] Table 1-2 In this embodiment, the F-Theta distortion curve, field curvature curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown.

[0072] Figure 2 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 field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within 0~2%, indicating that the optical lens can effectively correct distortion.

[0073] Figure 3 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 field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.2 mm to 0.1 mm, indicating that the optical lens can effectively correct the field curvature.

[0074] Figure 4 The diagram shows the axial aberration curves for Example 1, representing 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. The diagram shows that the axial aberration offset is controlled within ±0.04 mm, indicating that the optical lens can effectively correct axial aberrations.

[0075] 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 (0.940 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, indicating that the optical lens can effectively correct chromatic aberration.

[0076] Example 2

[0077] Please see Figure 6The figure shown is a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0078] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0079] 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.

[0080] Table 2-2 In this embodiment, the F-Theta distortion curve, field curvature curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0081] from Figure 7 As can be seen, the F-Theta distortion of the optical lens is controlled within ±1%, indicating that the optical lens can effectively correct distortion.

[0082] from Figure 8 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.2mm to 0.1mm, indicating that the optical lens can effectively correct the field curvature.

[0083] from Figure 9 As can be seen, the axial aberration offset is controlled within -0.03mm to 0.05mm, indicating that the optical lens can effectively correct axial aberration.

[0084] from Figure 10 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±3μm, indicating that the optical lens can effectively correct chromatic aberration.

[0085] Example 3

[0086] 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 object side surface S5 of the third lens L3 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0087] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0088] 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.

[0089] Table 3-2 In this embodiment, the F-Theta distortion curve, field curvature curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 300 are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0090] from Figure 12 As can be seen, the F-Theta distortion of the optical lens is controlled within ±1%, indicating that the optical lens can effectively correct distortion.

[0091] from Figure 13 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.1mm, indicating that the optical lens can effectively correct the field curvature.

[0092] from Figure 14 As can be seen, the axial aberration offset is controlled within -0.03mm to 0.04mm, indicating that the optical lens can effectively correct axial aberration.

[0093] from Figure 15 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±3μm, indicating that the optical lens can effectively correct chromatic aberration.

[0094] Please refer to Table 4 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, maximum field of view FOV, principal ray incident angle CRA at the maximum image height of the optical lens, and the values ​​corresponding to each conditional expression in each embodiment.

[0095] Table 4 In summary, the optical lens provided by the present invention employs six lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as ultra-wide angle, large aperture, miniaturization, small CRA, large image plane, and high imaging quality.

[0096] 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.

[0097] 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, 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 surface is convex and image side surface is concave; a second lens with negative optical power, whose object side surface is concave near the optical axis and image side surface is concave; a third lens with positive optical power, whose image side surface is convex; a fourth lens with positive optical power, whose object side surface is concave and image side surface is convex; a fifth lens with negative optical power, whose object side surface is convex and image side surface is concave near the optical axis; a sixth lens with positive optical power, whose object side surface is convex and image side surface is concave near the optical axis; wherein the real image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 2.5<IH / f<2.6; the maximum field of view angle FOV of the optical lens and the maximum chief ray incident angle CRA of the optical lens satisfy: 17<FOV / CRA<30; the total optical length TTL of the optical lens and the F-number Fno of the optical lens satisfy: 18mm<TTL / Fno<19mm.

2. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -2.7<f1 / f<-2.2; the curvature radius R1 of the object side surface of the first lens and the focal length f1 of the first lens satisfy: -3.4<R1 / f1<-2.

1.

3. The optical lens according to claim 1, characterized in that, The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -4.5<f2 / f<-3.5; the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 7<R4 / f<13.

4. The optical lens according to claim 1, characterized in that, The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2.2<f3 / f<3.6; the curvature radius R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: -2.2<R6 / f<-2.

1.

5. The optical lens according to claim 1, characterized in that, The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 5.5<f4 / f<6.

5.

6. The optical lens according to claim 1, characterized in that, The focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -90<f5 / f<-75.

7. The optical lens according to claim 1, characterized in that, The focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 6.3<f6 / f<8.

1.

8. The optical lens according to claim 1, characterized in that, The combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: -1.5<f12 / f<-1.

2.

9. The optical lens according to claim 1, characterized in that, The combined focal length f3456 of the third lens, the fourth lens, the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 1.5<f3456 / f<1.8.

Images