Optical lens

Abstract

The application provides an optical lens, which comprises seven lenses in sequence along an optical axis from an object side to an imaging surface, and the seven lenses comprise: a first lens with negative optical power, wherein the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; a second lens with negative optical power, wherein the object side surface of the second lens is a concave surface; a third lens with positive optical power; a fourth lens with positive optical power, wherein the image side surface of the fourth lens is a convex surface; a fifth lens with negative optical power, wherein the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a concave surface; a sixth lens with positive optical power, wherein the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface; and a seventh lens with positive optical power, wherein the object side surface of the seventh lens is a convex surface. The optical lens provided by the application has one or more advantages of good infrared confocal effect, large field of view, large aperture and miniaturization, etc.

Description

TECHNICAL FIELD

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

[0002] Infrared confocal lenses are widely used in Internet of Things devices because they can collect optical information in the visible light and infrared wave bands and can image well in both daytime and nighttime environments. Among them, infrared confocal is a lens technology specification currently proposed in the vehicle-mounted and security industries, and is a development trend in the future market. However, most of the infrared confocal lenses currently used in vehicle-mounted and security industries not only need to have high-definition imaging quality, but also need to ensure high-quality image output under different light conditions in daytime and nighttime, and also need to have strong environmental adaptability to ensure that the lens can maintain good resolution in high and low temperature environments. However, the lenses on the market are difficult to meet the above requirements at the same time, so there is an urgent need to design a lens with large light flux, clear imaging, light structure and day and night confocal to better meet the use requirements. SUMMARY

[0003] In view of the above problems, the purpose of the present application is to provide an optical lens with the advantages of infrared confocal and excellent imaging quality.

[0004] The present application provides an optical lens, which has seven lenses, and includes, in order along the optical axis from the object side to the imaging surface:

[0005] The first lens has negative focal power, the object side surface is convex, and the image side surface is concave;

[0006] The second lens has negative focal power, and the object side surface is concave;

[0007] The third lens has positive focal power;

[0008] The fourth lens has positive focal power, and the image side surface is convex;

[0009] The fifth lens has negative focal power, the object side surface is concave, and the image side surface is concave;

[0010] The sixth lens has positive focal power, the object side surface is convex, and the image side surface is convex;

[0011] The seventh lens has positive focal power, and the object side surface is convex;

[0012] The effective focal length f of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.4<IH / f<2.6.

[0013] It is further preferred that a maximum field of view FOV of the optical lens and an aperture value Fno of the optical lens satisfy: 110° < FOV / Fno < 130°.

[0014] It is further preferred that an effective focal length f of the optical lens and a focal length f1 of the first lens satisfy: -2.3 < f1 / f < -2; the focal length f1 of the first lens, a radius of curvature R1 of an object side surface of the first lens and a radius of curvature R2 of an image side surface of the first lens satisfy: -0.5 < f1 / (R1+R2) < -0.2.

[0015] It is further preferred that an effective focal length f of the optical lens and a focal length f2 of the second lens satisfy: -3.6 < f2 / f < -1.9; a radius of curvature R3 of an object side surface of the second lens and the effective focal length f of the optical lens satisfy: -1.4 < R3 / f < -1.3.

[0016] It is further preferred that an effective focal length f of the optical lens and a focal length f3 of the third lens satisfy: 1.6 < f3 / f < 2.9.

[0017] It is further preferred that an effective focal length f of the optical lens and a focal length f4 of the fourth lens satisfy: 2.3 < f4 / f < 3.5; a radius of curvature R8 of an image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -2.5 < R8 / f < -1.8.

[0018] It is further preferred that an effective focal length f of the optical lens and a focal length f5 of the fifth lens satisfy: -1.3 < f5 / f < -0.9; the focal length f5 of the fifth lens, a radius of curvature R9 of an object side surface of the fifth lens and a radius of curvature R10 of an image side surface of the fifth lens satisfy: 2.6 < (R9-R10) / f5 < 3.1.

[0019] It is further preferred that an effective focal length f of the optical lens and a focal length f6 of the sixth lens satisfy: 1.6 < f6 / f < 2.4; a radius of curvature R12 of an image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -5.1 < R12 / f < -2.1.

[0020] It is further preferred that an effective focal length f of the optical lens and a focal length f7 of the seventh lens satisfy: 2.8 < f7 / f < 3.2; a radius of curvature R13 of an object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1.4 < R13 / f < 1.7.

[0021] It is further preferred that a radius of central ray on an object side CSD11 of the first lens and a radius of central ray on an object side CSD71 of the seventh lens satisfy: 1.1 < CSD11 / CSD71 < 1.4.

[0022] The optical lens provided by the application adopts seven 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 good infrared confocal effect, large field of view, large aperture, miniaturization, excellent imaging quality and the like. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, including the cooperation of the following drawings, in which:

[0024] Figure 1 It is a structural schematic diagram of the optical lens in embodiment 1 of the application.

[0025] Figure 2 It is an F-Theta distortion curve diagram of the optical lens in embodiment 1 of the application.

[0026] Figure 3 It is a field curvature curve diagram of the optical lens in embodiment 1 of the application.

[0027] Figure 4 It is a sagittal chromatic aberration curve diagram of the optical lens in embodiment 1 of the application.

[0028] Figure 5 It is a structural schematic diagram of the optical lens in embodiment 2 of the application.

[0029] Figure 6 It is an F-Theta distortion curve diagram of the optical lens in embodiment 2 of the application.

[0030] Figure 7 It is a field curvature curve diagram of the optical lens in embodiment 2 of the application.

[0031] Figure 8 It is a sagittal chromatic aberration curve diagram of the optical lens in embodiment 2 of the application.

[0032] Figure 9 It is a structural schematic diagram of the optical lens in embodiment 3 of the application.

[0033] Figure 10 It is an F-Theta distortion curve diagram of the optical lens in embodiment 3 of the application.

[0034] Figure 11 It is a field curvature curve diagram of the optical lens in embodiment 3 of the application.

[0035] Figure 12 It is a sagittal chromatic aberration curve diagram of the optical lens in embodiment 3 of the application.

[0036] Figure 13 Structure diagram of the optical lens in embodiment 4 of the present application.

[0037] Figure 14 F-Theta distortion curve diagram of the optical lens in embodiment 4 of the present application.

[0038] Figure 15 Field curvature curve diagram of the optical lens in embodiment 4 of the present application.

[0039] Figure 16 Axial chromatic aberration curve diagram of the optical lens in embodiment 4 of the present application.

[0040] Figure 17 Structure diagram of the optical lens in embodiment 5 of the present application.

[0041] Figure 18 F-Theta distortion curve diagram of the optical lens in embodiment 5 of the present application.

[0042] Figure 19 Field curvature curve diagram of the optical lens in embodiment 5 of the present application.

[0043] Figure 20 Axial chromatic aberration curve diagram of the optical lens in embodiment 5 of the present application.

[0044] Figure 21 Structure diagram of the optical lens in embodiment 6 of the present application.

[0045] Figure 22 F-Theta distortion curve diagram of the optical lens in embodiment 6 of the present application.

[0046] Figure 23 Field curvature curve diagram of the optical lens in embodiment 6 of the present application.

[0047] Figure 24 Axial chromatic aberration curve diagram of the optical lens in embodiment 6 of the present application.

[0048] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0049] 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 should be understood that these detailed descriptions are merely descriptive of embodiments of the present application and are not intended in any way to limit the scope of the present application. Throughout the specification, the same reference numbers refer to the same elements. The expression “and / or” includes any and all combinations of one or more of the associated listed items.

[0050] It should be noted that the terms first, second, third, etc. in the present specification are only used to distinguish one feature from another, 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.

[0051] 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 surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn strictly to scale.

[0052] In the present specification, 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 referred to as the object side surface of the lens, and the surface of each lens closest to the imaging surface is referred to as the image side surface of the lens.

[0053] It should also be understood that the terms "comprises", "comprising", "includes", "including", "has", "having" and / or "contains", when used in this specification, specify the presence of stated features, elements and / or components, but do not preclude the presence or addition of one or more other features, elements, components and / or groups thereof. Furthermore, as used herein, the term "and / or" means "and", "or", or both, for example, "A and / or B" means "A and B", "A or B", or both "A and B".

[0054] 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 the terms 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.

[0055] 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 combination with the embodiments.

[0056] The optical lens of the embodiment of the present application comprises, 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, a sixth lens, and a seventh lens.

[0057] 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 negative focal power, a concave object side surface, and a concave or convex image side surface. The third lens can have a positive focal power, a concave or convex object side surface, and a concave or convex image side surface. The fourth lens can have a positive focal power, a concave or convex object side surface, and a convex image side surface. The fifth lens can have a negative focal power, a concave object side surface, and a concave image side surface. The sixth lens can have a positive focal power, a convex object side surface, and a convex image side surface. The seventh lens can have a positive focal power, a convex object side surface, and a concave or convex image side surface.

[0058] In some embodiments, the optical lens can further include a diaphragm, which can be located between the third lens and the fourth lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging. In addition, when the diaphragm is located between the third lens and the fourth lens, the diaphragm can reasonably distribute the functions of the first lens to the seventh lens, for example, the first lens, the second lens, and the third lens can be used to receive light to a greater extent, and the fourth lens to the seventh lens can be used to correct the function of the aberration, which is beneficial to balance the structure of the entire optical system. In addition, when the diaphragm is located between the third lens and the fourth lens, the correction of the diaphragm aberration is facilitated.

[0059] In some embodiments, the optical lens can further include a filter, which can be disposed between the seventh lens and the imaging surface. The filter is used to filter out interference light to prevent interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0060] In some embodiments, the fifth lens and the sixth lens can be glued to form a glued lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens. In addition, the glued lens can 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.

[0061] In some embodiments, the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.4<IH / f<2.6. By satisfying the above condition, the ratio of the effective focal length and the image height of the optical lens is controlled. Shortening the effective focal length can expand the field angle, so that the optical lens can shoot a wider object side space. At the same time, it can ensure that the chip matches a large image surface, that is, the optical lens has the characteristics of large field angle and large image surface.

[0062] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 110°<FOV / Fno<130°. Satisfying the above condition formula ensures that the optical lens satisfies the ultra-large field of view and large aperture, reduces the influence of the off-axis aberration on the system, makes the optical lens have the characteristics of large aperture, high relative luminance, and small distortion, and further improves the imaging quality.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.3<f1 / f<-2. Satisfying the above condition formula sets the first lens of the optical lens as a negative focal length lens, which can capture light rays at a large angle entering the optical lens, expand the field of view range of the optical lens, and at the same time, is beneficial to reducing the sensitivity of the optical lens and realizing the miniaturization design of the optical lens.

[0064] In some embodiments, the focal length f1 of the first lens, the object side surface curvature radius R1 of the first lens, and the image side surface curvature radius R2 of the first lens satisfy: -0.5<f1 / (R1+R2)<-0.2. Satisfying the above condition formula can constrain the surface shape of the object side surface and the image side surface of the first lens, which is beneficial to reducing the bending degree of the light rays at the image side surface of the first lens, reducing the astigmatism of the optical lens, balancing the astigmatism problem brought by the large field of view of the optical lens, making the astigmatism not too large while the optical lens has a large field of view, and further ensuring that the optical lens has excellent imaging quality.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -3.6<f2 / f<-1.9. Satisfying the above condition formula makes the second lens have a negative focal length, ensures that the light ray bundle entering the second lens diverges, makes the large field of view light rays slowly rise, is beneficial to realizing the large aperture and large target surface, at the same time, is beneficial to the smooth light ray trend, reduces the aberration, and is beneficial to realizing the high imaging quality.

[0066] In some embodiments, the object side surface curvature radius R3 of the second lens and the effective focal length f of the optical lens satisfy: -1.4<R3 / f<-1.3. Satisfying the above condition formula sets the shape of the object side surface of the second lens as a concave surface, makes the light rays passing through the first lens shrink into the second lens, reduces the size of the rear lens, helps 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.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.6 < f3 / f < 2.9. By satisfying the above condition, the light path from the first lens and the second lens is adjusted 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, so that the optical lens has the characteristics of large field of view, low sensitivity and miniaturization.

[0068] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.3 < f4 / f < 3.5. By satisfying the above condition, the aberration of the edge field of view is effectively improved by setting the fourth lens with a larger positive refractive power, and the overall imaging quality of the optical lens is improved.

[0069] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.3 < f4 / f < 3.5. By satisfying the above condition, the aberration of the edge field of view is effectively improved by setting the fourth lens with a larger positive refractive power, and the overall imaging quality of the optical lens is improved.

[0070] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.3 < f5 / f < -0.9. By satisfying the above condition, the fifth lens can have a smaller negative refractive power, which is beneficial to correct the aberration caused by the front lens and avoid excessive divergence of the rear light.

[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.3 < f5 / f < -0.9. By satisfying the above condition, the fifth lens can have a smaller negative refractive power, which is beneficial to correct the aberration caused by the front lens and avoid excessive divergence of the rear light.

[0072] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.6 < f6 / f < 2.4. By satisfying the above condition, the sixth lens can have a larger positive refractive power, which is beneficial to reduce the eccentric sensitivity of the light beam imaging and correct the aberration of the optical lens to have better imaging quality.

[0073] In some embodiments, the image-side surface radius of curvature R12 of the sixth lens and the effective focal length f of the optical lens satisfy: -5.1 < R12 / f < -2.1. Satisfying the above condition formula, the image-side surface of the sixth lens is convex, the trend of the light rays exiting from the image-side surface of the sixth lens is limited, and the optical lens can satisfy a large field of view and a large imaging area while correcting the spherical aberration of the optical lens and improving the imaging quality of the optical lens.

[0074] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 2.8 < f7 / f < 3.2. Satisfying the above condition formula, the positive refractive power strength provided by the seventh lens to the optical lens can effectively correct the color aberration, and the seventh lens as the last lens in the optical lens can correct the aberration caused by the decentration of each lens on the object side, that is, the decentration sensitivity of the optical lens can be reduced, the astigmatism caused by the decentration of each lens on the object side can be suppressed, the aberration of the optical lens can be corrected, and the imaging resolution can be improved.

[0075] In some embodiments, the object-side surface radius of curvature R13 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.4 < R13 / f < 1.7. Satisfying the above condition formula, the surface shape of the image-side surface of the seventh lens is controlled, the spherical aberration of the optical lens is effectively corrected, the influence of the astigmatism on the imaging of the optical lens is reduced, and the trend of the light rays is adjusted, so that the optical lens has a large field of view and is ultra-thin.

[0076] In some embodiments, the object-side surface half-aperture radius CSD11 of the first lens and the object-side surface half-aperture radius CSD71 of the seventh lens satisfy: 1.1 < CSD11 / CSD71 < 1.4. Satisfying the above condition formula, the optical lens has a large aperture, can better realize the collection of a large-angle light ray, realize the ultra-wide-angle imaging of the optical lens, can increase the imaging area of the optical lens, and realize the large target imaging of the optical lens.

[0077] In some embodiments, the effective focal length f of the optical lens and the aperture value Fno of the optical lens satisfy: 1.4 mm < f / Fno < 1.8 mm. Satisfying the above condition formula, the optical lens has a large aperture, so that the optical lens has sufficient light amount, and the captured image is clearer; at the same time, the short focal length is matched with the large aperture, the optical lens has a large wide-angle view to capture more scene information, solves the problem of weak light shooting through the large aperture, and strengthens the picture layering with flexible depth of field control.

[0078] In some embodiments, the focal length f2 of the second lens and the center thickness CT2 of the second lens satisfy: -19 < f2 / CT2 < -3. Satisfying the above condition formula, the effective focal length and the thickness of the second lens can be reasonably configured, so that the light entering the optical lens is more gentle, the sensitivity of the optical lens is reduced, the aberration of the optical lens is corrected, and the imaging quality of the optical lens is improved.

[0079] In some embodiments, the half-field radius of the object side of the first lens CSD11 and the sagittal height of the half-field radius of the object side of the first lens SAG11 satisfy: 4.2 < CSD11 / SAG11 < 7.2. Satisfying the above condition formula, the object side of the first lens is limited, the optical lens meets the small aperture design requirement, the central field of view of the optical lens is compressed, and the imaging quality of the edge field is better.

[0080] In some embodiments, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 110° < FOV / Fno < 130°. Satisfying the above condition formula, the optical lens meets a certain large field angle and large aperture, the influence of off-axis aberration on the system is reduced, the imaging surface brightness is improved, and the imaging quality is improved.

[0081] In some embodiments, the half-field radius of the object side of the second lens CSD21 and the sagittal height of the half-field radius of the object side of the second lens SAG21 satisfy: -4.1 < CSD21 / SAG21 < -2.8. Satisfying the above condition formula, by adjusting the edge region surface of the object side of the second lens, the ghost reflection energy can be reduced and the field curvature can be optimized, and the imaging quality of the optical lens is improved.

[0082] In some embodiments, the half-field radius of the object side of the seventh lens CSD71 and the sagittal height of the half-field radius of the object side of the seventh lens SAG71 satisfy: 1.7 < CSD71 / SAG71 < 2.2. Satisfying the above condition formula, by adjusting the edge region surface of the object side of the seventh lens, the edge field light of the optical lens can be dispersed, and the off-axis aberration of the edge field of the optical lens can be corrected, and the imaging quality of the optical lens is improved.

[0083] In some embodiments, the optical lens satisfies the following conditional expressions: 2.2mm < f < 2.5mm; 1.45mm < EPD < 1.75mm; 19.5mm < TTL < 21mm; 1.4 ≤ Fno ≤ 1.55; 5.5mm < IH < 6mm; 175° < FOV < 180°. In the above conditional expressions, f represents the effective focal length of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the real image height corresponding to the maximum field angle of the optical lens, and FOV represents the maximum field angle of the optical lens. The optical lens satisfies the above conditional expressions, and has one or more advantages of large field angle, short total length, large aperture, large image surface, low distortion, and low sensitivity.

[0084] In some embodiments, the seven lenses in the optical lens can all be plastic lenses or adopt a glass-plastic hybrid material collocation structure. Preferably, the optical lens of the present application adopts a seven-lens glass-plastic hybrid collocation structure, which can improve the thermal stability. Specifically, the first lens and the fourth lens can be glass lenses, and the second lens, the third lens, the fifth lens, the sixth lens, and the seventh lens can all be plastic lenses. The glass-plastic hybrid structure improves the thermal stability, effectively reduces the cost, corrects the aberration, reduces the size, and provides an optical lens product with higher cost performance.

[0085] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better achieving lens miniaturization. More specifically, the first lens and the fourth lens in the optical lens of the present application adopt spherical lenses, and the second lens, the third lens, the fifth lens, the sixth lens, and the seventh lens all adopt aspherical lenses.

[0086] In various embodiments of the present application, when the lenses adopt aspherical lenses, the shape of each aspherical surface of the optical lens satisfies the following equation:

[0087] ;

[0088] 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, and F are the fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order surface coefficients, respectively.

[0089] The application will be further described in the following embodiments. In each embodiment, the thickness, the radius of curvature, 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 the preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments only, any changes, substitutions, combinations or simplifications made without departing from the innovative points of the application should be regarded as equivalent replacement, and are included in the protection scope of the application.

[0090] Embodiment 1

[0091] Please refer to Figure 1 , which is a structural schematic diagram of the optical lens 100 provided in the embodiment 1 of the application, the optical lens 100 includes, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, a diaphragm ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7 and a filter G1.

[0092] The first lens L1 has a negative optical power, the object side surface S1 is a convex surface, and the image side surface S2 is a concave surface.

[0093] The second lens L2 has a negative optical power, the object side surface S3 is a concave surface, and the image side surface S4 is a convex surface at the near optical axis.

[0094] The third lens L3 has a positive optical power, the object side surface S5 is a convex surface, and the image side surface S6 is a convex surface.

[0095] The fourth lens L4 has a positive optical power, the object side surface S7 is a convex surface, and the image side surface S8 is a convex surface.

[0096] The fifth lens L5 has a negative optical power, the object side surface S9 is a concave surface, and the image side surface is a concave surface.

[0097] The sixth lens L6 has a positive optical power, the object side surface is a convex surface, and the image side surface S11 is a convex surface.

[0098] The fifth lens L5 and the sixth lens L6 form a cemented lens group with an optical power, that is, the cemented surface of the image side surface of the fifth lens L5 and the object side surface of the sixth lens L6 is S10.

[0099] The seventh lens L7 has a positive optical power, the object side surface S12 is a convex surface, and the image side surface S13 is a concave surface.

[0100] The object side surface S14 and the image side surface S15 of the filter G1 are both flat surfaces.

[0101] The imaging surface S16 is a flat surface.

[0102] 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 and the seventh lens L7 are plastic aspherical lenses.

[0103] The related parameters of the lenses in the optical lens 100 in Example 1 are shown in Table 1-1.

[0104] Table 1-1

[0105]

[0106] The surface parameters of the aspherical lenses of the optical lens 100 in Example 1 are shown in Table 1-2.

[0107] Table 1-2

[0108]

[0109] In this embodiment, the F-Theta distortion curve, the field curvature curve and the transverse chromatic aberration curve of the optical lens 100 are shown in Figure 2 、 Figure 3 、 Figure 4 respectively.

[0110] Figure 2 The F-Theta distortion curve of Example 1 is shown, which represents the F-Theta distortion of light rays at different image heights on the imaging plane, the horizontal axis represents the F-Theta distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within-25%~0, which shows that the optical lens can well correct the distortion.

[0111] Figure 3 The field curvature curve of Example 1 is shown, which represents the curvature degree of light rays on the meridional 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 meridional image surface and the sagittal image surface is controlled within ±0.02mm, which shows that the optical lens can well correct the field curvature.

[0112] Figure 4 The transverse chromatic aberration curve of Example 1 is shown, which represents the chromatic aberration of each wavelength at different image heights on the imaging plane, the horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. As can be seen from the figure, the transverse chromatic aberration of the longest wavelength and the shortest wavelength is controlled within 0~2μm, which shows that the optical lens can better correct the chromatic aberration.

[0113] Example 2

[0114] Please refer to Figure 5The 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 object side surface S5 of the third lens L3 is concave; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0115] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0116] Table 2-1

[0117]

[0118] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0119] Table 2-2

[0120]

[0121] In this embodiment, the F-Theta distortion curve, field curvature curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 As shown.

[0122] from Figure 6 As can be seen, the F-Theta distortion of the optical lens is controlled within -20% to 0, indicating that the optical lens can effectively correct distortion.

[0123] from Figure 7 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.02mm to 0.04mm, indicating that the optical lens can effectively correct the field curvature.

[0124] from Figure 8 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 2μm, indicating that the optical lens can correct chromatic aberration well.

[0125] Example 3

[0126] Please see Figure 9 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 image-side surface S6 of the third lens L3 is concave, the image-side surface S13 of the seventh lens L7 is convex, and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0127] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0128] Table 3-1

[0129]

[0130] The surface shape parameters of the aspherical lenses of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0131] Table 3-2

[0132]

[0133] In the present embodiment, the F-Theta distortion curve, the field curvature curve and the axial chromatic aberration curve of the optical lens 300 are shown in Figure 10 , Figure 11 , Figure 12 respectively.

[0134] As can be seen from Figure 10 , the F-Theta distortion of the optical lens is controlled within -20%~0, which indicates that the optical lens can well correct the distortion.

[0135] As can be seen from Figure 11 , the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.04mm~0.02mm, which indicates that the optical lens can well correct the field curvature.

[0136] As can be seen from Figure 12 , the axial chromatic aberration of the longest wavelength and the shortest wavelength is controlled within 0~2μm, which indicates that the optical lens can well correct the chromatic aberration.

[0137] Embodiment 4

[0138] Please refer to Figure 13 , which is a structural schematic diagram of the optical lens 400 provided in Embodiment 4 of the present application. Compared with Embodiment 1, the main difference is that the image side S4 of the second lens L2 is a concave surface; the image side S13 of the seventh lens L7 is a convex surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

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

[0140] Table 4-1

[0141]

[0142] The surface shape parameters of the aspherical lenses of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0143] Table 4-2

[0144]

[0145] In this embodiment, the F-Theta distortion curve, field curvature curve, and transverse chromatic aberration curve of the optical lens 400 are respectively as follows: Figure 14 , Figure 15 , Figure 16 As shown.

[0146] from Figure 14 As can be seen, the F-Theta distortion of the optical lens is controlled within -20% to 0, indicating that the optical lens can effectively correct distortion.

[0147] from Figure 15 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.02mm, indicating that the optical lens can effectively correct the field curvature.

[0148] from Figure 16 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 2μm, indicating that the optical lens can correct chromatic aberration well.

[0149] Example 5

[0150] Please see Figure 17 The figure shows a schematic diagram of the structure of the optical lens 500 provided in Embodiment 5 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side S4 of the second lens L2 is concave, the object side S7 of the fourth lens L4 is concave, and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0151] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0152] Table 5-1

[0153]

[0154] The surface profile parameters of the aspherical lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0155] Table 5-2

[0156]

[0157] In this embodiment, the F-Theta distortion curve, field curvature curve, and transverse chromatic aberration curve of the optical lens 500 are respectively as follows: Figure 18 , Figure 19 , Figure 20 As shown.

[0158] from Figure 18 As can be seen, the F-Theta distortion of the optical lens is controlled within -25% to 0, indicating that the optical lens can effectively correct distortion.

[0159] From the Figure 19 , it can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.02mm, which shows that the optical lens can correct the field curvature well.

[0160] From the Figure 20 , it can be seen that the axial chromatic aberration of the longest wavelength and the shortest wavelength is controlled within-1μm~2μm, which shows that the optical lens can correct the chromatic aberration well.

[0161] Embodiment 6

[0162] Please refer to Figure 21 , which is a structural schematic diagram of the optical lens 600 provided in the embodiment 6 of the present application. Compared with the embodiment 1, the main difference is that the image side S4 of the second lens L2 is a concave surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0163] The related parameters of each lens in the optical lens 600 in the embodiment 6 are shown in Table 6-1.

[0164] Table 6-1

[0165]

[0166] The surface type parameters of the aspherical lens of the optical lens 600 in the embodiment 6 are shown in Table 6-2.

[0167] Table 6-2

[0168]

[0169] In this embodiment, the F-Theta distortion curve, the field curvature curve and the axial chromatic aberration curve of the optical lens 600 are shown in Figure 22 , Figure 23 , Figure 24 respectively.

[0170] From the Figure 22 , it can be seen that the F-Theta distortion of the optical lens is controlled within-20%~0, which shows that the optical lens can correct the distortion well.

[0171] From the Figure 23 , it can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.02mm, which shows that the optical lens can correct the field curvature well.

[0172] From the Figure 24 , it can be seen that the axial chromatic aberration of the longest wavelength and the shortest wavelength is controlled within-1μm~2μm, which shows that the optical lens can correct the chromatic aberration well.

[0173] Please refer to Table 7 for the optical characteristics corresponding to the above-mentioned embodiments, including the effective focal length f, the total track length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV, the chief ray angle of incidence CRA at the maximum image height, and the numerical value corresponding to each conditional expression in the embodiments.

[0174] Table 7

[0175]

[0176] In summary of the above embodiments, the optical lens provided by the present application adopts seven 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. The lens has one or more advantages of large field of view angle, large aperture, miniaturization, etc. while achieving good infrared confocal effect.

[0177] 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.

[0178] 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 scope of the patent of the present application. It should be noted that, for ordinary skilled persons 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, in total seven pieces of lenses, characterized in that, In order from the object side to the imaging surface along the optical axis, comprises successively: a first lens with negative focal power, the object side surface of which is convex, and the image side surface of which is concave; a second lens with negative focal power, the object side surface of which is concave; a third lens with positive focal power; a fourth lens with positive focal power, the image side surface of which is convex; a fifth lens with negative focal power, the object side surface of which is concave, and the image side surface of which is concave; a sixth lens with positive focal power, the object side surface of which is convex, and the image side surface of which is convex; a seventh lens with positive focal power, the object side surface of which is convex; wherein the effective focal length f of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.4 The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.3 2. The optical lens of claim 1, wherein, The maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 110° 3. The optical lens of claim 1, wherein, The object side surface half diameter of the seventh lens CSD71 and the object side surface half diameter sag height SAG71 of the seventh lens satisfy: 1.7 4. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -3.6 5. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.6 6. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.3 7. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.3 8. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.6 9. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 2.8 10. The optical lens of claim 1, wherein, The object side surface half diameter CSD11 of the first lens and the object side surface half diameter CSD71 of the seventh lens satisfy: 1.1 < CSD11 / CSD71 < 1.

4. 1.1 < CSD11 / CSD71 < 1.4.

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