Optical lens

Abstract

The application provides an optical lens, which comprises six lenses in sequence from an object side to an imaging surface along an optical axis, and the six lenses comprise: a first lens with negative optical power; a second lens with negative optical power; a third lens with positive optical power, the image side of the third lens is a convex surface; a fourth lens with positive optical power, the object side of the fourth lens is a convex surface; a fifth lens with negative optical power, the object side of the fifth lens is a convex surface, and the image side of the fifth lens is a concave surface; and a sixth lens with positive optical power, the object side of the sixth lens is a concave surface, and the image side of the sixth lens is a convex surface. The optical lens provided by the application adopts six lenses with specific optical power, 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 such as a large target surface, a large aperture, high imaging quality and the like.

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 continuous improvement of people's requirements for driving experience, vehicle application type optical lenses are increasingly used in intelligent driving, and vehicle optical lenses are continuously improving in the automotive industry.

[0003] Advanced Driver Assistance System (ADAS) plays an important role in intelligent driving, which collects environmental information through various lenses combined with sensors to ensure the safety of drivers. In addition to the requirements of optical lenses for the ADAS system, such as light and thin shape, high pixel, high resolution and other characteristics, the optical lens is also required to clearly image under low illumination conditions, so it is necessary to develop an optical lens with good imaging effect. SUMMARY

[0004] In view of the above problems, the purpose of the present application is to provide an optical lens with excellent imaging quality.

[0005] The technical scheme adopted by the present application is:

[0006] An optical lens, a total of six lenses, including in order along the optical axis from the object side to the imaging surface:

[0007] a first lens with negative focal power;

[0008] a second lens with negative focal power;

[0009] a third lens with positive focal power, the image side surface of which is convex;

[0010] a fourth lens with positive focal power, the object side surface of which is convex;

[0011] a fifth lens with negative focal power, the object side surface of which is convex, and the image side surface of which is concave;

[0012] a sixth lens with positive focal power, the object side surface of which is concave, and the image side surface of which is convex.

[0013] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.6 < TTL / f < 2.1.

[0014] Further preferably, the effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 1 < (IH / 2) / (f x tan(FOV / 2)) < 1.1.

[0015] It is further preferred that a real image height IH corresponding to a maximum field of view angle of the optical lens and an effective focal length f of the optical lens satisfy: 0.65<IH / f<0.7.

[0016] It is further preferred that an optical total length TTL of the optical lens, a maximum field of view angle FOV of the optical lens and a real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 50<180°×TTL / (IH / 2) / (FOV / 2)<58.

[0017] It is further preferred that a curvature radius R6 on an image side of the third lens and a curvature radius R7 on an object side of the fourth lens satisfy: (R6-R7) / (R6+R7)>3.8.

[0018] It is further preferred that a curvature radius R9 on an object side of the fifth lens and a curvature radius R10 on an image side of the fifth lens satisfy: 0.8<(R9-R10) / (R9+R10)<0.95.

[0019] It is further preferred that a curvature radius R11 on an object side of the sixth lens and a curvature radius R12 on an image side of the sixth lens satisfy: 0.02<(R11-R12) / (R11+R12)<0.45.

[0020] It is further preferred that the effective focal length f of the optical lens and a focal length f1 of the first lens satisfy: f1 / f<-6.

[0021] It is further preferred that the effective focal length f of the optical lens and a focal length f2 of the second lens satisfy: f2 / f<-4.

[0022] The optical lens provided by the present application adopts six 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 such as large target surface, large aperture, high 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, taken in conjunction with the following drawings, in which:

[0024] Figure 1 FIG. 1 is a structure diagram of an optical lens according to an embodiment of the present application.

[0025] Figure 2 FIG. 2 is a field curvature curve diagram of the optical lens according to the embodiment of the present application.

[0026] Figure 3F-Tan(Theta) Distortion curve of the optical lens in Embodiment 1 of the present application.

[0027] Figure 4 MTF curve of the optical lens in Embodiment 1 of the present application.

[0028] Figure 5 Structure diagram of the optical lens in Embodiment 2 of the present application.

[0029] Figure 6 Curvature of field curve of the optical lens in Embodiment 2 of the present application.

[0030] Figure 7 F-Tan(Theta) Distortion curve of the optical lens in Embodiment 2 of the present application.

[0031] Figure 8 MTF curve of the optical lens in Embodiment 2 of the present application.

[0032] Figure 9 Structure diagram of the optical lens in Embodiment 3 of the present application.

[0033] Figure 10 Curvature of field curve of the optical lens in Embodiment 3 of the present application.

[0034] Figure 11 F-Tan(Theta) Distortion curve of the optical lens in Embodiment 3 of the present application.

[0035] Figure 12 MTF curve of the optical lens in Embodiment 3 of the present application.

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

[0037] Figure 14 Curvature of field curve of the optical lens in Embodiment 4 of the present application.

[0038] Figure 15 F-Tan(Theta) Distortion curve of the optical lens in Embodiment 4 of the present application.

[0039] Figure 16 MTF curve of the optical lens in Embodiment 4 of the present application.

[0040] The following detailed description will further describe the present application in combination with the above-mentioned drawings. DETAILED DESCRIPTION

[0041] For a better understanding of the present application, various aspects of the present application will be presented in more detail by referring to the attached drawings. It should be understood that these detailed descriptions are merely descriptive of the embodiments of the present application and are not intended in any way to limit the scope of the present application. Throughout the specification, like drawing reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0042] It should be noted that the expressions first, second, third and the like in this specification are used only to distinguish one feature from another feature, and do not indicate any limitation of the features. Thus, the first lens discussed below can also be referred to as a second lens or a third lens without departing from the teachings of the present application.

[0043] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for the sake 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 to scale.

[0044] In this specification, the paraxial region refers to a region near the optical axis. If a 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 a 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 image plane is referred to as the image side surface of the lens.

[0045] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", 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, when describing the 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.

[0046] 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 be further understood that terms, such as those 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.

[0047] It should be noted that the embodiments and the features in the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0048] The optical lens provided by the embodiment of the present application comprises six lenses, which are sequentially arranged along the optical axis from the object side to the imaging surface as the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens.

[0049] In some embodiments, the first lens can have a negative focal power, the object side surface thereof can be a concave surface or a convex surface, and the image side surface thereof can be a concave surface or a convex surface. The second lens can have a negative focal power, the object side surface thereof can be a concave surface or a convex surface, and the image side surface thereof can be a concave surface or a convex surface. The third lens can have a positive focal power, the object side surface thereof can be a concave surface or a convex surface, and the image side surface thereof is a convex surface. The fourth lens can have a positive focal power, the object side surface thereof is a convex surface, and the image side surface thereof can be a concave surface or a convex surface. The fifth lens can have a negative focal power, the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface. The sixth lens can have a positive focal power, the object side surface thereof is a concave surface, and the image side surface thereof is a convex surface.

[0050] In some embodiments, the optical lens can further comprise a diaphragm, which can be located between the first lens and the second 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 first lens and the second lens, the correction of the diaphragm aberration is facilitated.

[0051] In some embodiments, the optical lens can further comprise a filter, which can be arranged between the sixth lens and the imaging surface. The filter is used to filter out the interference light to prevent the interference light from reaching the imaging surface of the optical lens and affecting the normal imaging.

[0052] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.6 < TTL / f < 2.1. Satisfying the above range is conducive to limiting the total length of the lens and achieving miniaturization.

[0053] In some embodiments, the effective focal length f of the optical lens, the maximum field of view FOV of the optical lens and the real image height IH corresponding to the maximum field of view of the optical lens satisfy: 1 < (IH / 2) / (f x tan(FOV / 2)) < 1.1. Satisfying the above range can control the optical lens to have small distortion and improve the imaging quality of the optical lens.

[0054] 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: 0.65 < IH / f < 0.7. Satisfying the above range controls the image height and the focal length of the optical lens within a reasonable range, which helps the optical lens to have the characteristics of a large image surface and improves the imaging quality.

[0055] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.2 < BFL / f < 0.33. Satisfying the above range, the optical lens is limited to have a suitable back focus, the positions of the lenses are reasonably arranged, and the processing and assembly difficulty is reduced.

[0056] In some embodiments, the total track length TTL of the optical lens, the maximum field of view FOV of the optical lens, and the real image height IH corresponding to the maximum field of view FOV of the optical lens satisfy: 50 < 180° x TTL / (IH / 2) / (FOV / 2) < 58. Satisfying the above range, the length of the optical lens is limited under the same imaging area and the same field of view, and the optical lens is miniaturized.

[0057] In some embodiments, the total track length TTL of the optical lens and the sum ∑CT of the center thicknesses of the first lens to the sixth lens along the optical axis satisfy: 0.6 < ∑CT / TTL < 0.7. Satisfying the above range, the total track length of the optical lens and the sum of the thicknesses of the lenses are reasonably configured, which is helpful to realize high-pixel characteristics and improve the imaging quality of the optical lens.

[0058] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: f1 / f < -6. Satisfying the above range, the first lens has a negative optical power, which has a diverging effect on the light passing through it, and is beneficial to realize a small front-end aperture.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: f2 / f < -4. Satisfying the above range, the second lens has a negative optical power, which has a diverging light effect, further diverges the light emitted from the image side of the first lens under the same field of view, disperses the central light and the edge light of each field of view, and can make the rear optical system have a larger light receiving surface to receive the light emitted from the image side of the second lens, realize a larger light amount, and is beneficial to increase the relative illumination.

[0060] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.9 < f3 / f < 1.2. Satisfying the above range, the third lens is limited to have a suitable positive optical power, which has a converging light effect, and is matched with the negative optical power of the second lens, which can further converge the light passing through the second lens, and lower the height of the peripheral light, which is beneficial to the reduction of the aperture of the rear-end lens.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.8 < f4 / f < 1.2. Satisfying the above range, the fourth lens is defined to have appropriate positive refractive power, which is beneficial to light convergence. And the cooperation of the fourth lens with positive refractive power and the fifth lens with negative refractive power can adjust the optical path difference between different fields of view, improve resolution, and is beneficial to the gentle entry of light into the rear lens, which can further reduce the field curvature and correct the off-axis point aberration of the optical lens.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -0.8 < f5 / f < -0.5. Satisfying the above range, the fifth lens is defined to have appropriate negative refractive power, which can diverge the light emitted by the fourth lens, make the light of the edge field have an upward trend, and is beneficial to the image point on the imaging surface away from the optical axis, so as to realize the effect of matching with a large chip, obtain a larger picture, effectively eliminate aberration, and improve the resolving power of the optical lens.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: f6 / f > 3.5. Satisfying the above range, the sixth lens is defined to have positive refractive power, which is beneficial to light convergence, makes the light trend transition smoothly to the rear, reduces the height of the light incident to the rear, slows down the upward trend of the light, avoids the light energy loss caused by the large view field light reaching the imaging surface and the main light angle of the chip being too large, is beneficial to improving the illumination of the edge field, and is beneficial to realizing a short total optical length.

[0064] In some embodiments, the image side surface curvature radius R6 of the third lens and the object side surface curvature radius R7 of the fourth lens satisfy: (R6-R7) / (R6+R7) > 3.8. Satisfying the above range, the image side surface of the third lens and the object side surface of the fourth lens have an approximately symmetric structure, which can converge light, reduce the aperture of the rear lens, and smoothly transfer the light collected by the front lens to the rear lens.

[0065] In some embodiments, the object side surface curvature radius R9 of the fifth lens and the image side surface curvature radius R10 of the fifth lens satisfy: 0.8 < (R9-R10) / (R9+R10) < 0.95. Satisfying the above range, the field curvature of the optical lens can be reduced, the light can reach the imaging surface smoothly, the divergent light can be reasonably converged to the rear system, the light can be turned and collected to reach the imaging surface faster, the optical total length of the optical lens can be reduced, and the relative illumination of the edge field can be improved after the divergent edge field light is converged and smoothly enters the rear lens.

[0066] In some embodiments, the sixth lens satisfies the following condition: 0.02<(R11-R12) / (R11+R12)<0.45, where R11 is the curvature radius of the object side surface of the sixth lens, and R12 is the curvature radius of the image side surface of the sixth lens. When the above condition is satisfied, the edge field of view light and the central light passing through the object side surface of the sixth lens can be turned up, and the light passing through the image side surface of the sixth lens can be made to have a gentle trend, thereby increasing the back focal length and reducing the CRA.

[0067] In some embodiments, the optical lens satisfies the following condition: 14mm<f<15mm; 30°<FOV<40°; 9mm<EPD<9.5mm; 24mm<TTL<29mm; 1.5<Fno<1.8; 9.5mm<IH<10.5mm; 15°<CRA<21°; 3mm<BFL<5mm. In the above condition, 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, IH represents the real image height corresponding to the maximum field of view angle of the optical lens, CRA represents the chief ray incidence angle at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. When the above condition is satisfied, the optical lens has one or more advantages such as large target surface, large aperture, long focal length, etc.

[0068] 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 by the low dispersion characteristic of the glass itself. The optical lens provided by the present application can adopt a full-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

[0069] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens can adopt a spherical lens or an aspherical lens. 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 second lens, the third lens, the fourth lens, and the fifth lens of the present application adopt a spherical lens, and the first lens and the sixth lens adopt an aspherical lens.

[0070] 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:

[0071] ;

[0072] Wherein, z is the distance of the curved surface and the curved surface vertex in the direction of the optical axis, h is the distance of the optical axis to the curved surface, c is the curvature of the curved surface vertex, K is the quadratic curved surface coefficient, B, C, D, E, F are the fourth order, sixth order, eighth order, tenth order, twelfth order curved surface coefficient respectively.

[0073] 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 change, replacement, combination or simplification made without departing from the innovative points of the application should be regarded as equivalent replacement, and all are included in the protection scope of the application.

[0074] Embodiment 1

[0075] Please refer to Figure 1 , which is a structural schematic diagram of the optical lens provided in the embodiment 1 of the application, the optical lens includes, along the optical axis from the object side to the imaging surface, a first lens L1, a diaphragm ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter G1.

[0076] The first lens L1 has negative focal power, the object side S1 thereof is a concave surface, and the image side S2 thereof is a convex surface;

[0077] The second lens L2 has negative focal power, the object side S3 thereof is a concave surface, and the image side S4 thereof is a convex surface;

[0078] The third lens L3 has positive focal power, the object side S5 and the image side S6 thereof are both convex surfaces;

[0079] The fourth lens L4 has positive focal power, the object side S7 thereof is a convex surface, and the image side S8 thereof is a concave surface;

[0080] The fifth lens L5 has negative focal power, the object side S9 thereof is a convex surface, and the image side S10 thereof is a concave surface;

[0081] The sixth lens L6 has positive focal power, the object side S11 thereof is a concave surface, and the image side S12 thereof is a convex surface;

[0082] The object side S13 and the image side S14 of the filter G1 are both flat surfaces;

[0083] The imaging surface S15 is a flat surface.

[0084] The first lens L1 and the sixth lens L6 adopt glass aspherical lenses, and the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 adopt glass spherical lenses.

[0085] The related parameters of each lens in the optical lens in Example 1 are shown in Table 1-1.

[0086] Table 1-1

[0087]

[0088] The surface shape parameters of the aspherical lens of the optical lens in Example 1 are shown in Table 1-2.

[0089] Table 1-2

[0090]

[0091] In this embodiment, the field curvature curve, F-Tan(Theta) distortion curve and MTF curve of the optical lens are shown in Figure 2 , Figure 3 , Figure 4 respectively.

[0092] Figure 2 The field curvature curve of Example 1 is shown, which represents the curvature of light rays of different wavelengths 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: °). It can be seen from the figure that the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.1 mm, which shows that the optical lens can well correct the field curvature.

[0093] Figure 3 The F-Tan(Theta) distortion curve of Example 1 is shown, which represents the distortion of light rays of different wavelengths at different image heights on the imaging surface, the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the distortion of the optical lens is controlled within ±6%, which shows that the optical lens can well correct the distortion.

[0094] Figure 4 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies under each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF value of this embodiment is above 0.28 in the full field of view, and in the range of 0-120 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in low frequency and high frequency conditions.

[0095] Example 2

[0096] Please refer to Figure 5, which is a structural schematic view of the optical lens provided in Embodiment 2 of the present application. Compared with Embodiment 1, the main difference is that the object side S1 of the first lens L1 is a convex surface; the image side S2 of the first lens L1 is a concave surface; and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0097] The related parameters of each lens in the optical lens in Embodiment 2 are shown in Table 2-1.

[0098] Table 2-1

[0099]

[0100] The surface type parameters of the aspherical lens of the optical lens in Embodiment 2 are shown in Table 2-2.

[0101] Table 2-2

[0102]

[0103] In this embodiment, the field curvature curve, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens are shown in Figure 6 , Figure 7 , Figure 8 respectively.

[0104] As can be seen from Figure 6 , the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.05 mm, which indicates that the optical lens can well correct the field curvature.

[0105] As can be seen from Figure 7 , the distortion of the optical lens is controlled within ±3%, which indicates that the optical lens can well correct the distortion.

[0106] As can be seen from Figure 8 , the MTF value of this embodiment is above 0.2 in the full field of view, and in the range of 0-120 lp / mm, the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view, and the optical lens has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0107] Embodiment 3

[0108] Please refer to Figure 9, which is a structural schematic view of the optical lens provided in Embodiment 3 of the present application. Compared with Embodiment 1, the main difference of the present embodiment is that: the object side S1 of the first lens L1 is a convex surface; the image side S2 of the first lens L1 is a concave surface; the object side S3 of the second lens L2 is a convex surface; the image side S4 of the second lens L2 is a concave surface; the object side S5 of the third lens L3 is a concave surface; the image side S8 of the fourth lens L4 is a convex surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0109] The related parameters of each lens in the optical lens in Embodiment 3 are shown in Table 3-1.

[0110] Table 3-1

[0111]

[0112] The surface type parameters of the aspherical lens of the optical lens in Embodiment 3 are shown in Table 3-2.

[0113] Table 3-2

[0114]

[0115] In the present embodiment, the field curvature curve, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens are shown in Figure 10 , Figure 11 , Figure 12 respectively.

[0116] As can be seen from Figure 10 , the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.05mm, which indicates that the optical lens can well correct the field curvature.

[0117] As can be seen from Figure 11 , the distortion of the optical lens is controlled within ±4%, which indicates that the optical lens can well correct the distortion.

[0118] As can be seen from Figure 12 , the MTF value of the present embodiment is above 0.3 in the full field of view, and in the range of 0-120lp / mm, the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view, and the optical lens has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0119] Embodiment 4

[0120] Please refer to Figure 13Figure 4 shows a structural schematic diagram of an optical lens provided in Embodiment 4 of the present application, which differs from Embodiment 1 mainly in that: the object side S1 of the first lens L1 is a convex surface; the image side S2 of the first lens L1 is a concave surface; the object side S5 of the third lens L3 is a concave surface; the image side S8 of the fourth lens L4 is a convex surface; and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0121] The related parameters of each lens in the optical lens in Embodiment 4 are shown in Table 4-1.

[0122] Table 4-1

[0123]

[0124] The surface type parameters of the aspherical lens of the optical lens in Embodiment 4 are shown in Table 4-2.

[0125] Table 4-2

[0126]

[0127] In this embodiment, the field curvature curve, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens are shown in Figures Figure 14 , Figure 15 , Figure 16 respectively.

[0128] As can be seen from Figure 14 , the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.1 mm, which indicates that the optical lens can correct the field curvature well.

[0129] As can be seen from Figure 15 , the distortion of the optical lens is controlled within ±4%, which indicates that the optical lens can correct the distortion well.

[0130] As can be seen from Figure 16 , the MTF value of this embodiment is above 0.2 in the full field of view, and the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view in the range of 0-120 lp / mm, which has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0131] Table 5 shows the optical properties 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 and the numerical value corresponding to each conditional expression in each embodiment.

[0132] Table 5

[0133]

[0134] In summary, the optical lens provided by the present application adopts six 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 such as large target surface, large aperture, high imaging quality, etc.

[0135] In the description of the present specification, the description of 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.

[0136] The above-described embodiments only express several implementation manners of the present application, and the description is more 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, six pieces of lenses in total, characterized in that, In order from the object side to the imaging plane along the optical axis, the optical lens comprises in sequence: a first lens with negative refractive power; a second lens with negative refractive power; a third lens with positive refractive power, an image side surface of which is convex; a fourth lens with positive refractive power, an object side surface of which is convex; a fifth lens with negative refractive power, an object side surface of which is convex and an image side surface of which is concave; a sixth lens with positive refractive power, an object side surface of which is concave and an image side surface of which is convex; An optical total length TTL of the optical lens and an effective focal length f of the optical lens satisfy: 1.6 < TTL / f < 2.

1. A real image height IH corresponding to a maximum field angle of view FOV of the optical lens and the effective focal length f of the optical lens satisfy: 0.65 < IH / f < 0.

7. The effective focal length f of the optical lens satisfies: 14 mm < f < 15 mm.

2. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and a back focal length BFL of the optical lens satisfy: 0.2 < BFL / f < 0.

33.

3. The optical lens of claim 1, wherein, The effective focal length f of the optical lens, the maximum field angle of view FOV of the optical lens and the real image height IH corresponding to the maximum field angle of view FOV of the optical lens satisfy: 1 < (IH / 2) / (f*tan(FOV / 2)) < 1.

1.

4. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and a focal length f3 of the third lens satisfy: 0.9 < f3 / f < 1.2, and the effective focal length f of the optical lens and a focal length f4 of the fourth lens satisfy: 0.8 < f4 / f < 1.

2.

5. The optical lens of claim 1, wherein, The optical total length TTL of the optical lens, the maximum field angle of view FOV of the optical lens and the real image height IH corresponding to the maximum field angle of view FOV of the optical lens satisfy: 50 < 180°*TTL / (IH / 2) / (FOV / 2) < 58.

6. The optical lens of claim 1, wherein, An image side surface curvature radius R6 of the third lens and an object side surface curvature radius R7 of the fourth lens satisfy: 1264.38 ≥ (R6-R7) / (R6+R7) > 3.

8.

7. The optical lens of claim 1, wherein, An object side surface curvature radius R9 of the fifth lens and an image side surface curvature radius R10 of the fifth lens satisfy: 0.8 < (R9-R10) / (R9+R10) < 0.

95.

8. The optical lens of claim 1, wherein, An object side surface curvature radius R11 of the sixth lens and an image side surface curvature radius R12 of the sixth lens satisfy: 0.02 < (R11-R12) / (R11+R12) < 0.

45.

9. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and a focal length f1 of the first lens satisfy: -10.28 ≤ f1 / f < -6.

10. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and a focal length f2 of the second lens satisfy: -6.86 ≤ f2 / f < -4.

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