Optical lens

Abstract

The invention provides an optical lens, which comprises nine lenses from an object side to an imaging surface along an optical axis: a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; the sixth lens has negative focal power; the seventh lens has positive focal power; the eighth lens has negative focal power; and the ninth lens has positive focal power. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal power distribution, the lens has one or more advantages of short focus, miniaturization, large field angle, large aperture, large target surface, low distortion and low sensitivity.

Description

TECHNICAL FIELD

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

[0002] With the rapid development of the fields of unmanned aerial vehicles, security and protection, automobiles, meteorology, medical treatment, VR, AR and the like, higher and higher requirements are put forward for the field of view of the lenses carried thereby. A wide-angle lens can compress the edge field of view light as much as possible by introducing barrel distortion, and thus realize an ultra-wide-angle lens. At present, the ultra-wide-angle lens still has many problems, for example, the common ultra-wide-angle lens has a small aperture, which can cause insufficient light entering the lens, unclear imaging in a dark environment, and the like. In addition, there are problems such as great difficulty in aberration correction, great distortion, defocus in high-low temperature environments and the like. SUMMARY

[0003] In view of the above problems, the present application aims to provide an optical lens, which has the advantages of excellent imaging quality.

[0004] The present application provides an optical lens, which has nine lenses in total, and comprises, along the optical axis from the object side to the imaging surface, in sequence: a first lens with negative focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a second lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a third lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a fourth lens with negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; a fifth lens with positive focal 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 negative focal power, the image side surface of which is a concave surface; a seventh lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; an eighth lens with negative focal power, the image side surface of which is a concave surface at the near optical axis; a ninth lens with positive focal power, the object side surface of which is a convex surface at the near optical axis, and the image side surface of which is a concave surface at the near optical axis; wherein the maximum field of view FOV of the optical lens, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 60°<(FOVxf) / IH<95°.

[0005] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.4<TTL / f<6.5.

[0006] It is further preferred that the effective focal length f of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.6 < f / EPD < 2.1.

[0007] It is further preferred that the real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4.2 < IH / EPD < 4.6.

[0008] It is further preferred that the central thickness CT2 of the second lens and the edge thickness ET2 of the second lens satisfy: 1.4 < CT2 / ET2 < 2.1.

[0009] It is further preferred that the central thickness CT2 of the second lens and the edge thickness ET2 of the second lens satisfy: 1.4 < CT2 / ET2 < 2.1.

[0010] It is further preferred that the effective focal length f of the optical lens, the radian value θ of the maximum field angle of the optical lens, and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.6 < IH / (f x θ) < 0.9.

[0011] It is further preferred that the central thickness CT9 of the ninth lens and the half-radii sagittal height SAG91 of the object side surface of the ninth lens satisfy: -1.3 < CT9 / SAG91 < -0.7.

[0012] It is further preferred that the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 2.9 < f2 / f < 9.4.

[0013] It is further preferred that the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 3.6 < f3 / f < 5.3.

[0014] Compared with the prior art, the optical lens provided by the present application adopts nine lenses with specific optical powers, and 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 improved, so that the lens has one or more advantages of short focal length, miniaturization, large field angle, large aperture, large target surface, low distortion, and low sensitivity. BRIEF DESCRIPTION OF DRAWINGS

[0015] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings in which: Figure 1 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

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

[0017] Figure 3 Field curvature curve diagram of the optical lens in Embodiment 1 of the present application.

[0018] Figure 4 Vernier curve diagram of the optical lens in Embodiment 1 of the present application.

[0019] Figure 5 Structure schematic diagram of the optical lens in Embodiment 2 of the present application.

[0020] Figure 6 F-Theta distortion curve diagram of the optical lens in Embodiment 2 of the present application.

[0021] Figure 7 Field curvature curve diagram of the optical lens in Embodiment 2 of the present application.

[0022] Figure 8 Vernier curve diagram of the optical lens in Embodiment 2 of the present application.

[0023] Figure 9 Structure schematic diagram of the optical lens in Embodiment 3 of the present application.

[0024] Figure 10 F-Theta distortion curve diagram of the optical lens in Embodiment 3 of the present application.

[0025] Figure 11 Field curvature curve diagram of the optical lens in Embodiment 3 of the present application.

[0026] Figure 12 Vernier curve diagram of the optical lens in Embodiment 3 of the present application.

[0027] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0028] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It is to be understood that the detailed description is merely descriptive of embodiments of the present application and is not intended to limit the scope of the present application in any way. Throughout the description, like reference numerals refer to like elements. The expression “and / or” includes any and all combinations of one or more of the associated listed items.

[0029] It should be noted that, in the present specification, the expressions first, second, third, and the like are merely used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0030] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0031] In this document, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

[0032] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, mean that something is included, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. In addition, when expressions such as "at least one of" appear after a list of features, the expression is intended to modify the entire list of features and not the individual elements of the list. Furthermore, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the word "exemplary" is intended to mean an example or an illustration.

[0033] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (e.g., terms defined in commonly used dictionaries) should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0034] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0035] The optical lens provided by the embodiments of the present application comprises nine lenses, and the optical lens comprises, along the optical axis from the object side to the imaging surface, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens.

[0036] In some embodiments, the first lens can have a negative focal power, a convex object side surface, and a concave image side surface. The second lens can have a positive focal power, a convex object side surface, and a concave image side surface. The third lens can have a positive focal power, a convex object side surface, and a concave image side surface. The fourth lens can have a negative focal power, a concave object side surface, and a convex image side surface. The fifth lens can have a positive focal power, a convex object side surface, and a convex image side surface. The sixth lens can have a negative focal power, a convex or concave object side surface, and a concave image side surface. The seventh lens can have a positive focal power, a convex object side surface, and a convex image side surface. The eighth lens can have a negative focal power, a convex or concave object side surface, and a concave image side surface at the near optical axis. The ninth lens can have a positive focal power, a convex object side surface at the near optical axis, and a concave image side surface at the near optical axis.

[0037] In some embodiments, the optical lens can further include a diaphragm, which can be located between the fourth lens and the fifth lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging. When the diaphragm is located between the fourth lens and the fifth lens, the correction of the diaphragm aberration is facilitated.

[0038] In some embodiments, the optical lens can further include a filter, which is arranged between the ninth lens and the imaging surface. The filter is used to filter out interference light to prevent the interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0039] In some embodiments, the maximum field of view FOV of the optical lens, the effective focal length f of the optical lens, and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 60° < (FOV x f) / IH < 95°. Satisfying the above condition formula makes the optical lens have good optical performance, realizes the characteristics of high-pixel imaging of the optical lens, can well capture the details of the object, and is also beneficial to obtain a larger field of view while reducing the deflection angle of the outgoing light, thereby reducing the dark corner and suppressing distortion.

[0040] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.4 < TTL / f < 6.5. Satisfying the above condition formula can reasonably configure the ratio of the total optical length and the effective focal length of the optical lens, which is beneficial to realize the miniaturization design of the optical lens, and at the same time, is also beneficial to the optical lens to have a reasonable field of view range while realizing a certain focal length characteristic, thereby satisfying the wide-angle design of the optical lens, so that the optical lens can obtain sufficient object side space information.

[0041] In some embodiments, the effective focal length f of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.6 < f / EPD < 2.1. By satisfying the above condition, by controlling the ratio of the effective focal length and the entrance pupil diameter of the optical lens, the receiving ability of the optical lens to light is improved, as much information as possible on the object side is obtained, and imaging information with higher brightness and resolution is obtained.

[0042] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4.2 < IH / EPD < 4.6. By satisfying the above condition, by controlling the relationship between the entrance pupil diameter and the image height of the optical lens, the width of the light beam entering the optical lens is appropriate, which is conducive to the improvement of the image plane brightness, and the image plane area and the field of view range of the optical lens are appropriate.

[0043] In some embodiments, the sagittal height of half the entrance pupil radius SAG21 of the object side of the second lens and the center thickness CT2 of the second lens satisfy: 1 < SAG21 / CT2 < 1.2. By satisfying the above condition, the surface shape of the object side of the second lens can be reasonably controlled, which is conducive to reducing the deflection angle of light in the optical lens, thereby reducing the sensitivity of the edge light of the optical lens and improving the resolution.

[0044] In some embodiments, the center thickness CT2 of the second lens and the edge thickness ET2 of the second lens satisfy: 1.4 < CT2 / ET2 < 2.1. By satisfying the above condition, by controlling the center thickness and the edge thickness of the second lens within a certain range, the aberration generated by the optical lens can be effectively balanced, which is also conducive to the adjustment of the field curvature in engineering production, and thus is conducive to improving the imaging quality of the optical lens.

[0045] In some embodiments, the effective focal length f of the optical lens, the radian value θ of the maximum field of view angle of the optical lens, and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.6 < IH / (f x θ) < 0.9. By satisfying the above condition, the edge distortion of the optical lens can be controlled, which is conducive to realizing the characteristics of a large field of view angle and a large image plane of the optical lens, and effectively improving the proportion of the edge field of view in the entire image plane, so that the optical lens satisfies the high-pixel characteristics and the imaging quality of the optical lens is improved.

[0046] In some embodiments, the center thickness CT9 of the ninth lens and the sagittal height of half the entrance pupil radius SAG91 of the object side of the ninth lens satisfy: -1.3 < CT9 / SAG91 < -0.7. By satisfying the above condition, while satisfying the flexural force, the center thickness of the ninth lens is avoided to be too large or the object side is too curved to increase the difficulty of lens manufacturing, thereby reducing the production cost.

[0047] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 2.9 < f2 / f < 9.4. Satisfying the above condition formula, the large-angle light rays are incident into the optical lens with the cooperation of the first lens, so as to expand the field of view angle of the optical lens, and the astigmatism and chromatic aberration of the optical lens are corrected, and the imaging quality of the optical lens is improved.

[0048] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 3.6 < f3 / f < 5.3. Satisfying the above condition formula, by setting the third lens with positive refractive power and limiting the ratio of the focal length of the third lens to the effective focal length of the optical lens, the light ray trend from the first lens and the second lens is adjusted, and the edge aberration is corrected, and the imaging resolution is improved.

[0049] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -20 < f4 / f < -6. Satisfying the above condition formula, as the intermediate lens of the imaging lens group, the fourth lens provides negative refractive power for the optical lens, which can better constrain the light beam, so as to correct the chromatic aberration of the optical lens, and the aberration of each lens on the object side due to eccentricity error can be corrected in the middle, and the correction pressure of the rear lens group is reduced.

[0050] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -2.4 < f6 / f < -1.4. Satisfying the above condition formula, the focal length value of the sixth lens is reasonably controlled, the large field of view light is slowly lifted, the parallel light trend of the light beam changes to the divergent trend, which is beneficial to control the back focus of the lens, and is beneficial to realize large target surface and reduce the chief ray incidence angle.

[0051] In some embodiments, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: -7.9 < f8 / f < -3.7. Satisfying the above condition formula, the width of the light beam is expanded, so that the light beam with a larger angle is expanded in width after passing through the first lens to the seventh lens, and the wide light beam is fully incident on the imaging surface of the optical lens, so that the optical lens has a wider field of view range, and high-pixel imaging is realized.

[0052] In some embodiments, the total optical length TTL of the optical lens and the aperture value Fno of the optical lens satisfy: 5.8 mm < TTL / Fno < 9.2 mm. Satisfying the above condition 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 also obtain sufficient light quantity in a dark environment, and the high-quality and high-definition shooting needs are met.

[0053] In some embodiments, the object-side half-field radius CSD11 of the first lens and the object-side half-field radius sagittal height SAG11 of the first lens satisfy: 3.5 < CSD11 / SAG11 < 4.2. Satisfying the above condition formula, the large-angle light is incident to the optical lens, the imaging quality of the optical lens is high, the first lens object-side surface profile is not over-bent, the processing difficulty of the first lens is reduced, the problem of uneven coating caused by the first lens being too curved is avoided, and the problem of the first lens object-side surface being too flat is also avoided, thereby reducing the risk of ghosting.

[0054] In some embodiments, the center thickness CT9 of the ninth lens and the object-side half-field radius sagittal height SAG91 of the ninth lens and the image-side half-field radius sagittal height SAG92 of the ninth lens satisfy: -2.5 < (SAG91 + SAG92) / CT9 < -1.3. Satisfying the above condition formula, the refractive power and thickness of the ninth lens in the direction perpendicular to the optical axis are controlled, the ninth lens is not too thick or too thin, the incidence angle of the light on the object-side surface of the ninth lens is reduced, and the tolerance sensitivity of the optical lens is reduced; at the same time, the ninth lens has multiple inflection points, which is beneficial to correcting the distortion and field curvature generated by the object-side lens of the ninth lens, and the refractive power of the multiple lenses close to the imaging surface of the optical lens is uniformly distributed.

[0055] In some embodiments, the optical lens satisfies the following condition formula: 2.2 mm < f < 2.7 mm; 170° ≤ FOV < 220°; 1.3 mm < EPD < 1.5 mm; 11 mm < TTL < 15 mm; 1.6 < Fno ≤ 2; 5.9 mm < IH ≤ 6 mm; wherein f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle 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, and IH represents the image height corresponding to the maximum field of view angle of the optical lens. Satisfying the above condition formula, the optical lens has one or more advantages of short focal length, large field of view angle, large entrance pupil diameter, short total length, large aperture, large target surface, low distortion, low sensitivity, and the like.

[0056] In some embodiments, the lens material in the optical lens provided by the present application can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. When the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected due to the low dispersion characteristic of the glass itself. The first lens and the fourth lens in the optical lens provided by the present application can be made of glass, and the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens can be made of plastic. The glass-plastic hybrid structure can effectively reduce the cost, correct the aberration, reduce the volume, improve the thermal stability, and provide an optical lens product with higher cost performance.

[0057] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens can adopt a spherical lens or an aspherical lens. Compared with a spherical structure, an aspherical structure can effectively reduce aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better achieving miniaturization of the lens. More specifically, the first lens and the fourth lens of the present application adopt a spherical lens, and the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens adopt an aspherical lens.

[0058] In various embodiments of the present application, when the lens adopts an aspherical lens, the shape of each aspherical surface of the optical lens satisfies the following equation: ; wherein z is the distance of the curved surface from the vertex of the curved surface in the direction of the optical axis, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the quadratic surface coefficient, and B, C, D, E, F, G, H, I, J are respectively the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, sixteenth-order, eighteenth-order and twentieth-order surface coefficients.

[0059] The present application is further described in the following embodiments. In various embodiments, the thickness, the radius of curvature and the material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present application, but the embodiments of the present application are not limited to the following embodiments only, and any changes, substitutions, combinations or simplifications made without departing from the innovative points of the present application should be regarded as equivalent replacement modes, and are included in the protection scope of the present application.

[0060] Embodiment 1 Please refer to Figure 1 , which is a structural schematic diagram of the optical lens 100 provided in the embodiment 1 of the present application. The optical lens 100 includes, in order from the object side to the imaging surface S21 along the optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a diaphragm ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9 and a filter G1.

[0061] The first lens L1 has a negative focal power, the object side surface S1 thereof is a convex surface, and the image side surface S2 thereof is a concave surface. The second lens L2 has a positive focal power, the object side surface S3 thereof is a convex surface, and the image side surface S4 thereof is a concave surface. The third lens L3 has a positive focal power, the object side surface S5 thereof is a convex surface, and the image side surface S6 thereof is a concave surface. The fourth lens L4 has a negative focal power, the object side surface S7 thereof is a concave surface, and the image side surface S8 thereof is a convex surface. The fifth lens L5 has positive refractive power, the object side S9 is a convex surface, and the image side S10 is a convex surface; The sixth lens L6 has negative refractive power, the object side S11 is a concave surface, and the image side S12 is a concave surface; The seventh lens L7 has positive refractive power, the object side S13 is a convex surface, and the image side S14 is a convex surface; The eighth lens L8 has negative refractive power, the object side S15 is a concave surface, and the image side S16 is a concave surface at the near optical axis; The ninth lens L9 has positive refractive power, the object side S17 is a convex surface at the near optical axis, and the image side S18 is a concave surface at the near optical axis; The object side S19 and the image side S20 of the filter G1 are both flat surfaces; The imaging surface S21 is a flat surface.

[0062] The first lens L1 and the fourth lens L4 are glass spherical lenses; the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 are plastic aspherical lenses.

[0063] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0064] Table 1-1 The surface type parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0065] Table 1-2 In this embodiment, the F-Theta distortion curve, the field curvature curve, and the vertical axis chromatic aberration curve of the optical lens 100 are shown in FIGS. Figure 2 , Figure 3 , Figure 4

[0066] Figure 2 The F-Theta distortion curve of the optical lens 100 in this embodiment is shown in FIG., which represents the distortion of different field angles on the imaging surface. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the distortion value is controlled within -40%~0, which indicates that the optical lens 100 can correct the distortion well.

[0067] Figure 3 ​A field curvature curve of the optical lens 100 in the embodiment is shown, which represents the field curvature of light rays on the tangential image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the tangential image surface and the sagittal image surface is controlled within ±0.05mm, which shows that the optical lens 100 can better correct the field curvature.

[0068] Figure 4 A curve of the optical lens 100 in the embodiment is shown, which represents the field curvature of light rays on the tangential image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the tangential image surface and the sagittal image surface is controlled within ±0.05mm, which shows that the optical lens 100 can better correct the field curvature.

[0069] Embodiment 2 Please refer to Figure 5 , which is a structural schematic diagram of the optical lens 200 provided in the embodiment 2 of the application. Compared with the embodiment 1, the main difference is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0070] The related parameters of each lens in the optical lens 200 in the embodiment 2 are shown in Table 2-1.

[0071] Table 2-1 The surface type parameters of the aspherical lens of the optical lens 200 in the embodiment 2 are shown in Table 2-2.

[0072] Table 2-2 In the embodiment, the F-Theta distortion curve, the field curvature curve and the axial chromatic aberration curve of the optical lens 200 are shown in Figure 6 、 Figure 7 、 Figure 8 respectively.

[0073] As can be seen from Figure 6 , the distortion value is controlled within -35%~0, which shows that the optical lens 200 can better correct the distortion.

[0074] As can be seen from Figure 7 , the field curvature of the tangential image surface and the sagittal image surface is controlled within ±0.05mm, which shows that the optical lens 200 can better correct the field curvature.

[0075] As can be seen from Figure 8As can be seen from the Figs. 1 and 2, the sagittal chromatic aberration of the longest wavelength and the shortest wavelength is controlled within 0~5μm, which indicates that the optical lens 200 can correct the sagittal chromatic aberration well.

[0076] Embodiment 3 Please refer to Fig. 3, Figure 9 which is a structural schematic diagram of an optical lens 300 provided in Embodiment 3 of the present application. Compared with Embodiment 1, the main difference is that the object side S11 of the sixth lens L6 is a convex surface; the object side S15 of the eighth lens L8 is a convex surface; and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0077] The related parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0078] Table 3-1 The surface type parameters of the aspheric lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0079] Table 3-2 In this embodiment, the F-Theta distortion curve, the field curvature curve and the sagittal chromatic aberration curve of the optical lens 300 are shown in Figs. 3, Figure 10 , Figure 11 , Figure 12 respectively.

[0080] As can be seen from the Fig. 3, Figure 10 the distortion value is controlled within -15%~0, which indicates that the optical lens 300 can correct the distortion well.

[0081] As can be seen from the Fig. 3, Figure 11 the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.05mm~0.1mm, which indicates that the optical lens 300 can correct the field curvature well.

[0082] As can be seen from the Fig. 3, Figure 12 the sagittal chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1μm~3μm, which indicates that the optical lens 300 can correct the sagittal chromatic aberration well.

[0083] Please refer to Table 4, which is the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view, the chief ray angle CRA at the maximum image height, the maximum field of view FOV of the optical lens, and the numerical value corresponding to each conditional expression in each embodiment.

[0084] Table 4 In summary, the optical lens provided by the present application adopts nine lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens is improved, the aberration is reduced, and the imaging quality of the optical lens is improved, so that the lens has one or more advantages of short focal length, miniaturization, large field of view, large aperture, large target surface, low distortion, low sensitivity, and the like.

[0085] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0086] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An optical lens, comprising nine lenses, characterized in that: Along the optical axis from the object side to the imaging surface, it includes: The first lens has a negative optical power, its object-side surface is convex and its image-side surface is concave; a second lens having positive refractive power, whose object-side surface is convex and whose image-side surface is concave; a third lens element having positive optical power, whose object-side surface is convex and whose image-side surface is concave; a fourth lens element having negative optical power, whose object-side surface is concave and whose image-side surface is convex; a fifth lens element having positive refractive power, whose object-side surface and image-side surface are convex; a sixth lens element having negative optical power and a concave image-side surface; a seventh lens element having positive refractive power, whose object-side surface and image-side surface are convex; An eighth lens element having negative optical power, whose image-side surface is concave near the optical axis; The ninth lens element has positive refractive power, its object-side surface is convex near the optical axis, and its image-side surface is concave near the optical axis; The maximum field of view FOV of the optical lens, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy the following conditions: 60°<(FOV×f) / IH<95°.

2. The optical lens according to claim 1, wherein: The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.4 <TTL / f<6.5。 3. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the entrance pupil diameter EPD of the optical lens meet the following conditions: 1.6 <f / EPD<2.1。 4. The optical lens according to claim 1, wherein: The true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens meet the following requirements: 4.2 <IH / EPD<4.6。 5. The optical lens according to claim 1, wherein: The object side semi-aperture height SAG21 of the second lens and the center thickness CT2 of the second lens satisfy: 1 <SAG21 / CT2<1.2。 6. The optical lens according to claim 1, wherein: The center thickness CT2 of the second lens and the edge thickness ET2 of the second lens satisfy: 1.4 <CT2 / ET2<2.1。 7. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens, the arc value θ of the maximum field angle of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.6 <IH / (f×θ)<0.9。 8. The optical lens according to claim 1, wherein: The center thickness CT9 of the ninth lens and the object side semi-aperture height SAG91 of the ninth lens satisfy: -1.3 <CT9 / SAG91<-0.7。 9. The optical lens according to claim 1, wherein: The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 2.9 <f2 / f<9.4。 10. The optical lens according to claim 1, wherein: The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 3.6 <f3 / f<5.3。

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