Optical lens

Abstract

The application provides an optical lens, which comprises six lenses in sequence along an optical axis from an object side to an imaging surface, and the six lenses comprise: a first lens with negative optical power, wherein the object side surface of the first lens is a concave surface; a second lens with positive optical power, wherein the object side surface and the image side surface of the second lens are both convex surfaces; a third lens with positive optical power, wherein 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; a fourth lens with optical power, wherein 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; a fifth lens with positive optical power, wherein the object side surface of the fifth lens is a convex surface; and a sixth lens with negative optical power, wherein the image side surface of the sixth lens is a concave 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 used more and more in intelligent driving, and the position of vehicle optical lenses in the automobile industry is continuously improved.

[0003] Advanced Driver Assistance System (ADAS) plays an important role in intelligent driving. It collects environmental information through various lenses combined with sensors to ensure the safety of drivers. In addition to the requirements of optical lenses for ADAS systems, such as light and thin shape, high pixel, high resolution and other characteristics, the optical lenses also need to be able 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 the advantages of 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] The first lens with negative focal power, the object side surface is concave;

[0008] The second lens with positive focal power, both the object side surface and the image side surface are convex;

[0009] The third lens with positive focal power, the object side surface is convex, and the image side surface is concave;

[0010] The fourth lens with focal power, the object side surface is concave, and the image side surface is convex;

[0011] The fifth lens with positive focal power, the object side surface is convex;

[0012] The sixth lens with negative focal power, the image side surface is concave.

[0013] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.3 < TTL / f < 2.5.

[0014] Further preferably, the total optical 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: 40 < 180° x TTL / (IH / 2) / (FOV / 2) < 80.

[0015] Further preferably, the object-side surface aperture D1 of the first lens, a real image height IH corresponding to a maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 3 < D1 / IH / Tan(FOV / 2) < 4.

[0016] Further preferably, an effective focal length f of the optical lens and a curvature radius R1 of the object-side surface of the first lens satisfy: -1.7 < R1 / f < -0.6.

[0017] Further preferably, the effective focal length f of the optical lens and a curvature radius R9 of the object-side surface of the fifth lens satisfy: 0.4 < R9 / f < 1.1.

[0018] Further preferably, the effective focal length f of the optical lens and a curvature radius R12 of the image-side surface of the sixth lens satisfy: 0.2 < R12 / f < 0.8.

[0019] Further preferably, a curvature radius R3 of the object-side surface of the second lens and a curvature radius R4 of the image-side surface of the second lens satisfy: (R3-R4) / (R3+R4) <-1.6.

[0020] Further preferably, a curvature radius R5 of the object-side surface of the third lens and a curvature radius R6 of the image-side surface of the third lens satisfy: |(R5-R6) / (R5+R6)| < 0.85.

[0021] Further preferably, a curvature radius R7 of the object-side surface of the fourth lens and a curvature radius R8 of the image-side surface of the fourth lens satisfy: |(R7-R8) / (R7+R8)| < 0.85.

[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 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.

[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 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 of which is a concave surface, and the image side surface of which can be a concave surface or a convex surface. The second lens can have a positive focal power, both the object side surface and the image side surface of which are convex surfaces. The third lens can have a positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface. The fourth lens can have a positive focal power or a negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface. The fifth lens can have a positive focal power, the object side surface of which is a convex surface, and the image side surface of which can be a concave surface or a convex surface. The sixth lens can have a negative focal power, the object side surface of which can be a concave surface or a convex surface, and the image side surface of which is a concave 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: 1.3 < TTL / f < 2.5. Satisfying the above range is conducive to limiting the total length of the lens while better realizing the long-focus performance of the system.

[0053] In some embodiments, the effective focal length f of the optical lens, the maximum field of view FOV and the real image height IH corresponding to the maximum field of view satisfy: 0.95 < (IH / 2) / (f x tan(FOV / 2)) < 1.05. Satisfying the above range can control the size of the 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: 0.55 < IH / f < 0.7. Satisfying the above range controls the image height and 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 < 0.4. 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: 40 < 180° x TTL / (IH / 2) / (FOV / 2) < 80. Satisfying the above range, the relationship among the total length, the image height, and the field of view of the optical lens is balanced.

[0057] In some embodiments, the total track length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the sixth lens along the optical axis satisfy: 0.45 < ∑CT / TTL < 0.8. 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 object side aperture D1 of the first lens, the real image height IH corresponding to the maximum field of view FOV of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 3 < D1 / IH / Tan(FOV / 2) < 4. Satisfying the above range, the relationship among the front end aperture, the field of view, and the image size of the optical lens is balanced, which is beneficial to miniaturization.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.5 < f1 / f < -1.2. Satisfying the above range, the first lens has a negative focal length, which is beneficial to reduce the inclination angle of the incident light, collect the edge field of view light into the rear optical lens as much as possible, and realize large-angle light collection.

[0060] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1 < f2 / f < 1.9. Satisfying the above range, the second lens is limited to have a suitable positive focal length, which is beneficial to the convergence of light, makes the divergent light entering the system smoothly into the rear optical system, the light trend is more gentle, the aberration is optimized, and the resolution is improved.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1 < f3 / f < 7. Satisfying the above range, the third lens is limited to have a suitable positive focal length, which can effectively correct the aberration generated at the front end of the lens and improve the imaging quality of the lens.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: |f4 / f|>1. Satisfying the above range, the fourth lens is defined to have appropriate negative refractive power, which helps to increase the imaging area and improve the imaging quality.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.6

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.3

[0065] In some embodiments, the effective focal length f of the optical lens and the curvature radius R1 of the object side surface of the first lens satisfy: -1.7

[0066] In some embodiments, the effective focal length f of the optical lens and the curvature radius R9 of the object side surface of the fifth lens satisfy: 0.4

[0067] In some embodiments, the effective focal length f of the optical lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: 0.2

[0068] In some embodiments, the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: (R3-R4) / (R3+R4)<-1.6. Satisfying the above range, the light path can be controlled to be stable, the deflection degree of the light passing through the lens can be reduced, the difficulty of correcting the off-axis aberration can be reduced, and the imaging quality of the optical lens can be improved.

[0069] In some embodiments, the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: |(R5-R6) / (R5+R6)|<0.85. Satisfying the above range, the light path can be stable, and the difficulty of correcting the aberration of the rear lens of the optical lens can be reduced.

[0070] In some embodiments, the fourth lens satisfies the following condition: |(R7-R8) / (R7+R8)|<0.85, where R7 is the radius of curvature of the object side surface of the fourth lens, and R8 is the radius of curvature of the image side surface of the fourth lens. By satisfying the above range, the aberration can be effectively corrected, and the imaging quality of the optical lens can be improved.

[0071] In some embodiments, the optical lens satisfies the following condition: 14mm<f<16mm; 30°<FOV<40°; 8.5mm<EPD<10mm; 20mm<TTL<36mm; 1.5<Fno<1.8; 9mm<IH<10mm; 18°<CRA<23°; 3mm<BFL<5.5mm. 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 angle of incidence of the optical lens, and BFL represents the back focal length of the optical lens. By satisfying the above range, the optical lens has one or more advantages such as large target surface, large aperture, long focal length, etc.

[0072] 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 characteristics 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.

[0073] 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 first lens, the third lens, the fourth lens, and the fifth lens of the present application adopt a spherical lens, and the second lens and the sixth lens adopt an aspherical lens.

[0074] 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:

[0075] ;

[0076] 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.

[0077] The application will be further described in the following embodiments. In each embodiment, 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 the preferred embodiments of the application, but the embodiments of the 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 application should be regarded as equivalent replacement, and are included in the protection scope of the application.

[0078] Embodiment 1

[0079] Please refer to Figure 1 , which is a structural schematic diagram of the optical lens provided in the embodiment 1 of the application, and the optical lens comprises, 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.

[0080] The first lens L1 has a negative focal power, the object side surface S1 is a concave surface, and the image side surface S2 is a convex surface.

[0081] The second lens L2 has a positive focal power, and the object side surface S3 and the image side surface S4 are both convex surfaces.

[0082] The third lens L3 has a positive focal power, the object side surface S5 is a convex surface, and the image side surface S6 is a concave surface.

[0083] The fourth lens L4 has a negative focal power, the object side surface S7 is a concave surface, and the image side surface S8 is a convex surface.

[0084] The fifth lens L5 has a positive focal power, and the object side surface S9 and the image side surface S10 are both convex surfaces.

[0085] The sixth lens L6 has a negative focal power, the object side surface S11 is a convex surface, and the image side surface S12 is a concave surface.

[0086] The object side surface S13 and the image side surface S14 of the filter G1 are both flat surfaces.

[0087] The imaging surface S15 is a flat surface.

[0088] The second lens L2 and the sixth lens L6 are glass aspheric lenses, and the first lens L1, the third lens L3, the fourth lens L4, and the fifth lens L5 are glass spherical lenses.

[0089] The related parameters of each lens in the optical lens in the embodiment 1 are shown in Table 1-1.

[0090] Table 1-1

[0091]

[0092] The surface shape parameters of the aspherical lens of the optical lens in Embodiment 1 are shown in Table 1-2.

[0093] Table 1-2

[0094]

[0095] 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.

[0096] Figure 2 The field curvature curve of Embodiment 1 is shown, which represents the curvature degree 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 ±0.15 mm, which shows that the optical lens can well correct the field curvature.

[0097] Figure 3 The F-Tan(Theta) distortion curve of Embodiment 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 0~4%, the image compression in the edge angle region is relatively flat, and the clarity of the unfolded image is effectively improved.

[0098] Figure 4 The MTF (Modulation Transfer Function) curve of Embodiment 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 0.2 within the full field of view, and within the range of 0~120 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0099] Embodiment 2

[0100] Please refer to Figure 5 , which is a structural schematic diagram of the optical lens provided in Embodiment 2 of the present application, and compared with Embodiment 1, the main difference is that the object side S11 of the sixth lens L6 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0101] The related parameters of each lens in the optical lens in Embodiment 2 are shown in Table 2-1.

[0102] Table 2-1

[0103]

[0104] The surface type parameters of the aspherical lens of the optical lens in Embodiment 2 are shown in Table 2-2.

[0105] Table 2-2

[0106]

[0107] In this embodiment, the field curvature curve, F-Tan(Theta) distortion curve and MTF curve of the optical lens are shown in Figure 6 、 Figure 7 、 Figure 8 respectively.

[0108] As can be seen from Figure 6 , 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 well correct the field curvature.

[0109] As can be seen from Figure 7 , the distortion of the optical lens is controlled within -2%~0, which indicates that the optical lens can well correct the distortion.

[0110] As can be seen from Figure 8 , the MTF value of this embodiment is above 0.3 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 the case of low frequency and high frequency.

[0111] Embodiment 3

[0112] Please refer to Figure 9 , which is a structural schematic diagram of the optical lens provided in Embodiment 3 of the present application, and compared with Embodiment 1, the main difference is that: the image side surface S2 of the first lens L1 is a concave surface; the image side surface S10 of the fifth lens L5 is a concave surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0113] The related parameters of each lens in the optical lens in Embodiment 3 are shown in Table 3-1.

[0114] Table 3-1

[0115]

[0116] The surface type parameters of the aspherical lens of the optical lens in Embodiment 3 are shown in Table 3-2.

[0117] Table 3-2

[0118]

[0119] In the 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.

[0120] As can be seen from Figure 10 , 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 well correct the field curvature.

[0121] As can be seen from Figure 11 , the distortion of the optical lens is controlled within 0~4%, which indicates that the optical lens can well correct the distortion.

[0122] As can be seen from Figure 12 , the MTF value of the embodiment is above 0.3 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 the case of low frequency and high frequency.

[0123] Embodiment 4

[0124] Please refer to Figure 13 , which is a structural schematic diagram of the optical lens provided in the embodiment 4 of the present application, and the main difference between the embodiment and the embodiment 1 is that: the fourth lens L4 has positive refractive power; the image side surface S2 of the first lens L1 is a concave surface; the object side surface S11 of the sixth lens L6 is a concave surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0125] The related parameters of each lens in the optical lens in the embodiment 4 are shown in Table 4-1.

[0126] Table 4-1

[0127]

[0128] The surface type parameters of the aspherical lens of the optical lens in the embodiment 4 are shown in Table 4-2.

[0129] Table 4-2

[0130]

[0131] In the embodiment, the field curvature curve, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens are shown in Figure 14, Figure 15 , Figure 16 As shown.

[0132] from Figure 14 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.05mm, indicating that the optical lens can effectively correct the field curvature.

[0133] from Figure 15 As can be seen, the distortion of the optical lens is controlled within -3% to 0, indicating that the optical lens can effectively correct distortion.

[0134] from Figure 16 As can be seen, the MTF value of this embodiment is above 0.2 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0135] Please refer to Table 5 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0136] Table 5

[0137]

[0138] In summary, the optical lens provided by the present invention uses six lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as large target surface, large aperture, and high imaging quality.

[0139] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0140] The above 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 patent scope 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, several 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 surface along the optical axis, the optical lens comprises in sequence: a first lens with negative refractive power, the object side surface of which is a concave surface; a second lens with positive refractive power, both the object side surface and the image side surface of which are convex surfaces; a third lens with positive refractive power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; a fourth lens with positive refractive 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 refractive power, the object side surface of which is a convex surface; a sixth lens with negative refractive power, the image side surface of which is a concave surface; The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.3 < TTL / f < 2.

5. The total optical 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 of the optical lens satisfy: 40 < 180°×TTL / (IH / 2) / (FOV / 2) < 80. The effective focal length f of the optical lens satisfies: 14mm < f < 16mm. The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1 < f3 / f < 7. The effective focal length f of the optical lens and the image side surface curvature radius R12 of the sixth lens satisfy: 0.2 < R12 / f < 0.

8.

2. The optical lens of claim 1, wherein, The real image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 0.55 < IH / f < 0.

7.

3. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.5 < f1 / f < -1.2, and the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1 < f2 / f < 1.

9.

4. The optical lens of claim 1, wherein, The object side surface aperture D1 of the first lens, the real image height IH corresponding to the maximum field of view of the optical lens and the maximum field of view FOV of the optical lens satisfy: 3 < D1 / IH / Tan(FOV / 2) < 4.

5. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the object side surface curvature radius R1 of the first lens satisfy: -1.7 < R1 / f < -0.

6.

6. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the object side surface curvature radius R9 of the fifth lens satisfy: 0.4 < R9 / f < 1.

1.

7. 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: -1.3 < f6 / f < -0.

4.

8. The optical lens of claim 1, wherein, The object side surface curvature radius R3 of the second lens and the image side surface curvature radius R4 of the second lens satisfy: -14.88 ≤ (R3-R4) / (R3+R4) < -1.

6.

9. The optical lens of claim 1, wherein, The object side surface curvature radius R5 of the third lens and the image side surface curvature radius R6 of the third lens satisfy: 0.02 ≤ |(R5-R6) / (R5+R6)| < 0.

85.

10. The optical lens of claim 1, wherein, The object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: 0.36 ≤ |(R7-R8) / (R7+R8)| < 0.85.

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