Optical lens

Abstract

The invention provides an optical lens, which comprises six lenses from an object side to an imaging surface along an optical axis: a first lens with negative focal power; the second lens has negative focal power; the third lens has positive focal power, and the image side surface of the third lens is a convex surface; the fourth lens has positive focal power, and the object side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a concave surface; and the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a convex surface. According to the optical lens provided by the invention, the six lenses with specific focal power are adopted, and through specific surface shape matching and reasonable focal power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, the imaging quality of the optical lens can be improved, and the lens has one or more advantages of large target surface, large aperture, high imaging quality and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and in particular to an optical lens. Background Art

[0002] As people's requirements for driving experience continue to increase, automotive optical lenses are increasingly used in intelligent driving, and the status of automotive optical lenses in the automotive-related industries continues to improve.

[0003] Advanced driver assistance systems (ADAS) play an important role in intelligent driving. They use various lenses and sensors to collect environmental information to ensure the driver's driving safety. In addition to requiring the optical lens to be thin and short and have high pixels and high resolution, the existing ADAS system lens also requires the optical lens to be able to image clearly under low illumination conditions. Therefore, it is necessary to develop an optical lens with good imaging effect. Summary of the invention

[0004] In view of the above problems, an object of the present invention is to provide an optical lens having the advantage of excellent imaging quality.

[0005] The technical solution adopted by the present invention is:

[0006] An optical lens, comprising six lenses, which include:

[0007] a first lens having negative optical power;

[0008] a second lens having negative optical power;

[0009] A third lens element having positive refractive power and a convex image-side surface;

[0010] a fourth lens element having positive refractive power and a convex object-side surface;

[0011] a fifth lens having negative optical power, whose object side surface is convex and whose image side surface is concave;

[0012] The sixth lens element has positive refractive power, its object-side surface is concave, and its image-side surface 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 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×tan(FOV / 2))<1.1.

[0015] Further preferably, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.65 <IH / f<0.7。

[0016] 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 of the optical lens satisfy: 50<180°×TTL / IH / FOV<58.

[0017] Further preferably, a curvature radius R6 of the image side surface of the third lens and a curvature radius R7 of the object side surface of the fourth lens satisfy: (R6-R7) / (R6+R7)>3.8.

[0018] Further preferably, a curvature radius R9 of the object side surface of the fifth lens and a curvature radius R10 of the image side surface of the fifth lens satisfy: 0.8<(R9-R10) / (R9+R10)<0.95.

[0019] Further preferably, a curvature radius R11 of the object side surface of the sixth lens and a curvature radius R12 of the image side surface of the sixth lens satisfy: 0.02<(R11-R12) / (R11+R12)<0.45.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: f1 / f<-6.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: f2 / f<-4.

[0022] The optical lens provided by the present invention adopts six lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved, so that the lens has one or more advantages such as a large target surface, a large aperture, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

[0025] Figure 2 It is a field curvature curve diagram of the optical lens in Example 1 of the present invention.

[0026] Figure 3Graph showing the F-Tan (Theta) distortion of the optical lens in Example 1 of the present invention.

[0027] Figure 4 This is the MTF curve diagram of the optical lens in Example 1 of the present invention.

[0028] Figure 5 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0029] Figure 6 4 is a field curvature curve diagram of the optical lens in Example 2 of the present invention.

[0030] Figure 7 Graph showing the F-Tan (Theta) distortion of the optical lens in Example 2 of the present invention.

[0031] Figure 8 This is an MTF curve diagram of the optical lens in Example 2 of the present invention.

[0032] Fig. 9 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0033] Fig.10 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0034] Fig.11 Graph showing the F-Tan (Theta) distortion of the optical lens in Example 3 of the present invention.

[0035] Fig.12 This is the MTF curve diagram of the optical lens in Example 3 of the present invention.

[0036] Fig.13 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0037] Fig.14 It is a field curvature curve diagram of the optical lens in Example 4 of the present invention.

[0038] Fig.15 4 is a F-Tan (Theta) distortion curve of the optical lens in Example 4 of the present invention.

[0039] Fig.16 This is the MTF curve diagram of the optical lens in Example 4 of the present invention.

[0040] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0041] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0042] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0043] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0044] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0045] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0046] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

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

[0048] The optical lens provided by the embodiment of the present invention includes six lenses, which are, in order from the object side to the imaging surface along the optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens.

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

[0050] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the first lens and the second lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the image. When the diaphragm is located between the first lens and the second lens, it is convenient for correcting the diaphragm aberration.

[0051] In some embodiments, the optical lens may further include a filter, and the filter may be disposed between the sixth lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting 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. Meeting the above range is beneficial to limiting the total length of the lens and realizing 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 true image height IH corresponding to the maximum field of view of the optical lens satisfy: 1 < (IH / 2) / (f × tan(FOV / 2)) < 1.1. Meeting 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 true 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. Meeting the above range can control the image height and focal length of the optical lens within a reasonable range, which helps the optical lens to have the characteristic of a large image surface and improve 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. Meeting the above range defines that the optical lens has an appropriate back focal length, facilitating the reasonable arrangement of the positions of each lens and reducing the processing and assembly difficulty at the same time.

[0056] In some embodiments, the overall optical length TTL of the optical lens, the maximum field of view FOV of the optical lens, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 50 < 180°×TTL / IH / FOV < 58. Meeting the above range restricts the length of the optical lens under the condition of the same imaging area and the same field of view angle, realizing the miniaturization of the optical lens.

[0057] In some embodiments, the overall optical 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 respectively satisfy: 0.6 < ∑CT / TTL < 0.7. Meeting the above range reasonably configures the overall optical length of the optical lens and the sum of the thicknesses of each lens, which helps to achieve 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. Meeting the above range makes the first lens have a negative optical power, and it can have a diverging effect on the light passing through it, which is beneficial to achieving a small front 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. Meeting the above range makes the second lens have a negative optical power and has the effect of diverging light. At the same field of view angle, it further diverges the light emerging from the image side of the first lens, and can disperse the central light and the marginal light of each field of view, enabling the rear optical system to have a larger light receiving surface to receive the light emerging from the image side of the second lens, realizing a larger light input amount and being beneficial to increasing 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. Meeting the above range defines that the third lens has an appropriate positive optical power and has the effect of converging light. Matching with the negative optical power of the second lens, it can further converge the light passing through the second lens, reducing the height of the peripheral light, which is beneficial to reducing the aperture of the rear 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. Meeting the above range defines that the fourth lens has an appropriate positive optical power, which is conducive to the convergence of light. And by matching the fourth lens with a positive optical power and the fifth lens with a negative optical power, the optical path difference between different fields of view can be adjusted, the resolution can be improved, it is beneficial for light to enter the rear lens smoothly, and further the field curvature can be reduced and the off-axis aberration of the optical lens can be corrected.

[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. Meeting the above range defines that the fifth lens has an appropriate negative optical power, which can diverge the light emitted by the fourth lens, making the light in the marginal field of view show an upward trend, which is beneficial for the image point on the imaging surface to be away from the optical axis, so as to facilitate achieving the effect of matching with a large chip, obtaining a larger picture, effectively eliminating aberration, and improving the resolution 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. Meeting the above range defines that the sixth lens has a positive optical power, which is beneficial for the convergence of light, makes the light trend transition smoothly to the rear, reduces the height of the light incident on the rear, slows down the upward trend of the light, avoids the light energy loss caused by the excessive main ray angle between the large field of view light and the chip when reaching the imaging surface, is beneficial for improving the illuminance of the marginal field of view, and is beneficial for achieving a short overall optical length.

[0064] In some embodiments, the curvature radius R6 of the image side of the third lens and the curvature radius R7 of the object side of the fourth lens satisfy: (R6 - R7) / (R6 + R7) > 3.8. Meeting the above range, the image side of the third lens and the object side of the fourth lens are approximately symmetric structures, 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 curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side of the fifth lens satisfy: 0.8 < (R9 - R10) / (R9 + R10) < 0.95. Meeting the above range can reduce the field curvature of the optical lens, making the light reach the imaging surface smoothly; it can also reasonably converge the diverging light to the rear system, make the light turn and converge to reach the imaging surface faster, reduce the overall optical length of the optical lens; and can make the diverging marginal field of view light converge and then smoothly enter the rear lens, thereby achieving an increase in the relative illuminance of the marginal field of view.

[0066] In some embodiments, the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: 0.02 < (R11 - R12) / (R11 + R12) < 0.45. Meeting the above range can cause the marginal field light rays and central light rays passing through the object side surface of the sixth lens to turn upwards; at the same time, the light ray trend passing through the image side surface of the sixth lens is gentle, achieving the effects of increasing the back focal length and reducing the CRA.

[0067] In some embodiments, the optical lens satisfies the following conditional expressions: 14 mm < f < 15 mm; 30° < FOV < 40°; 9 mm < EPD < 9.5 mm; 24 mm < TTL < 29 mm; 1.5 < Fno < 1.8; 9.5 mm < IH < 10.5 mm; 15° < CRA < 21°; 3 mm < BFL < 5 mm. In the above conditional expressions, 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 overall optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, CRA represents the principal ray incident angle at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above range, the optical lens has at least one or more advantages such as a large target surface, a large aperture, and a long focal length characteristic.

[0068] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. Additionally, when the lens material is glass, due to the low dispersion characteristic of the glass itself, the geometric chromatic aberration of the optical system can be effectively corrected. The optical lens provided by the present invention can adopt an all-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 spherical lenses or aspherical lenses. Compared with the spherical lens 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 realizing the miniaturization of the lens. More specifically, the second lens, the third lens, the fourth lens, and the fifth lens of the present invention adopt spherical lenses, and the first lens and the sixth lens adopt aspherical lenses.

[0070] In each embodiment of the present invention, when the lens adopts an aspherical lens, the surface shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0071]

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

[0073] The present invention is further described below in multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different. For specific differences, please refer to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any other changes, substitutions, combinations or simplifications that do not deviate from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0074] Example 1

[0075] See also Figure 1 , which is a schematic diagram of the structure of the optical lens provided in Embodiment 1 of the present invention, wherein the optical lens includes, in sequence from the object side to the imaging surface along the optical axis: a first lens L1, an aperture 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 refractive power, its object side surface S1 is concave, and its image side surface S2 is convex;

[0077] The second lens L2 has negative refractive power, its object side surface S3 is concave, and its image side surface S4 is convex;

[0078] The third lens L3 has positive refractive power, and its object-side surface S5 and image-side surface S6 are both convex;

[0079] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is concave;

[0080] The fifth lens L5 has negative refractive power, its object-side surface S9 is convex, and its image-side surface S10 is concave;

[0081] The sixth lens L6 has positive refractive power, its object-side surface S11 is concave, and its image-side surface S12 is convex;

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

[0083] The imaging surface S15 is a plane.

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

[0085] The relevant 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 parameters of the aspherical lens of the optical lens in Example 1 are shown in Table 1-2.

[0089] Table 1-2

[0090] Face number K B C D E F S1 -8.50E-01 2.73E-04 1.50E-05 1.81E-10 -2.57E-09 -2.85E-11 S2 -5.99E-01 4.26E-04 1.04E-05 5.99E-08 4.93E-09 -1.64E-10 S11 2.17E+01 -4.35E-04 1.06E-05 -2.07E-06 6.03E-08 -5.50E-10 S12 2.19E+01 6.84E-05 2.52E-05 -2.48E-06 9.59E-08 -1.09E-09

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

[0092] Figure 2 The field curvature curve of Example 1 is shown, which indicates the degree of curvature of light of different wavelengths on the meridional image plane and the sagittal image plane, with the horizontal axis indicating the offset (unit: mm) and the vertical axis indicating the half field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.1 mm, indicating that the optical lens can correct the field curvature well.

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

[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 entire field of view, and in the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency conditions.

[0095] Example 2

[0096] See also Figure 5, which is a schematic diagram of the structure of the optical lens provided in Example 2 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the object side surface S1 of the first lens L1 is a convex surface; the image side surface S2 of the first lens L1 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

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

[0098] Table 2-1

[0099]

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

[0101] Table 2-2

[0102]

[0103]

[0104] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens are respectively as follows: Figure 6 , Figure 7 , Figure 8 shown.

[0105] from Figure 6 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.05mm, indicating that the optical lens can correct the field curvature well.

[0106] from Figure 7 It can be seen that the distortion of the optical lens is controlled within ±3%, indicating that the optical lens can correct the distortion well.

[0107] from Figure 8 It can be seen that the MTF value of this embodiment is above 0.2 in the whole field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0108] Example 3

[0109] See also Fig. 9, shown is a schematic diagram of the structure of the optical lens provided in Example 3 of the present invention. Compared with Example 1, the main differences of this embodiment are: the object-side surface S1 of the first lens L1 is a convex surface; the image-side surface S2 of the first lens L1 is a concave surface; the object-side surface S3 of the second lens L2 is a convex surface; the image-side surface S4 of the second lens L2 is a concave surface; the object-side surface S5 of the third lens L3 is a concave surface; the image-side surface S8 of the fourth lens L4 is a convex surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0110] The relevant parameters of each lens in the optical lens in Example 3 are shown in Table 3-1.

[0111] Table 3-1

[0112]

[0113]

[0114] The surface parameters of the aspherical lens of the optical lens in Example 3 are shown in Table 3-2.

[0115] Table 3-2

[0116] Face number K B C D E F S1 -2.09E+00 -3.67E-04 -2.13E-05 -5.94E-07 2.40E-08 -2.43E-10 S2 -7.99E-01 -6.47E-04 -2.84E-05 -4.63E-07 4.40E-08 -6.45E-10 S11 1.08E+01 -7.75E-04 -1.10E-04 1.63E-05 -1.50E-06 4.76E-08 S12 5.82E+00 -1.93E-04 -6.54E-05 7.59E-06 -4.58E-07 1.16E-08

[0117] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens are respectively as follows: Fig.10 , Fig.11 , Fig.12 shown.

[0118] from Fig.10 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.05mm, indicating that the optical lens can correct the field curvature well.

[0119] from Fig.11 It can be seen that the distortion of the optical lens is controlled within ±4%, indicating that the optical lens can correct the distortion well.

[0120] from Fig.12 It can be seen that the MTF value of this embodiment is above 0.3 in the whole field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0121] Example 4

[0122] See also Fig.13, which is a schematic diagram of the structure of the optical lens provided in Example 4 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the object-side surface S1 of the first lens L1 is a convex surface; the image-side surface S2 of the first lens L1 is a concave surface; the object-side surface S5 of the third lens L3 is a concave surface; the image-side surface S8 of the fourth lens L4 is a convex surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0123] The relevant parameters of each lens in the optical lens in Example 4 are shown in Table 4-1.

[0124] Table 4-1

[0125]

[0126]

[0127] The surface parameters of the aspherical lens of the optical lens in Example 4 are shown in Table 4-2.

[0128] Table 4-2

[0129] Face number K B C D E F S1 -2.14E+00 -3.62E-04 -2.09E-05 -5.85E-07 2.45E-08 -2.55E-10 S2 -8.05E-01 -6.43E-04 -2.84E-05 -4.33E-07 4.50E-08 -6.81E-10 S11 8.98E+00 -7.41E-04 -1.27E-04 1.63E-05 -1.45E-06 4.85E-08 S12 5.78E+00 -1.52E-04 -7.33E-05 7.65E-06 -4.46E-07 1.22E-08

[0130] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens are respectively as follows: Fig.14 , Fig.15 , Fig.16 shown.

[0131] from Fig.14 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.1mm, indicating that the optical lens can correct the field curvature well.

[0132] from Fig.15 It can be seen that the distortion of the optical lens is controlled within ±4%, indicating that the optical lens can correct the distortion well.

[0133] from Fig.16 It can be seen that the MTF value of this embodiment is above 0.2 in the whole field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0134] Please refer to Table 5, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the chief ray incident angle CRA at the maximum image height, the maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0135] Table 5

[0136] Parameters and Conditionals Example 1 Example 2 Example 3 Example 4 f(mm) 14.59 14.91 14.71 14.74 FOV(°) 36.00 36.00 36.00 36.00 EPD(mm) 9.12 9.32 9.19 9.21 TTL(mm) 28.78 25.25 24.92 25.31 Fno 1.60 1.60 1.60 1.60 IH(mm) 9.97 9.90 9.92 9.91 CRA(°) 17.94 18.95 19.94 19.94 BFL(mm) 4.41 3.50 3.50 4.24 TTL / f 1.97 1.69 1.69 1.72 (IH / 2) / (f×Tan(FOV / 2)) 1.05 1.02 1.04 1.03 IH / f 0.68 0.66 0.67 0.67 BFL / f 0.30 0.23 0.24 0.29 180°×TTL / IH / FOV 57.70 51.00 50.23 51.06 ΣCT / TTL 0.64 0.68 0.65 0.65 f1 / f -10.28 -10.06 -8.95 -6.25 f2 / f -6.86 -6.71 -5.08 -4.17 f3 / f 1.08 0.96 1.14 1.14 f4 / f 1.06 1.00 0.94 0.93 f5 / f -0.62 -0.65 -0.70 -0.73 f6 / f 3.98 7.81 6.00 8.60 (R6-R7) / (R6+R7) 4.57 4.02 1264.38 52.67 (R9-R10) / (R9+R10) 0.85 0.92 0.87 0.87 (R11-R12) / (R11+R12) 0.42 0.15 0.07 0.04

[0137] In summary of the above embodiments, the optical lens provided by the present invention adopts six lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it is possible to improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, so that the lens has one or more advantages such as a large target surface, a large aperture, and high imaging quality.

[0138] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0139] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical lens, comprising six lenses, characterized in that: Along the optical axis from the object side to the imaging surface, it includes: a first lens having negative optical power; a second lens having negative optical power; A third lens element having positive refractive power and a convex image-side surface; a fourth lens element having positive refractive power and a convex object-side surface; a fifth lens having negative optical power, whose object side surface is convex and whose image side surface is concave; The sixth lens element has positive refractive power, its object-side surface is concave, and its image-side surface is convex.

2. The optical lens according to claim 1, characterized in that: 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。 3. The optical lens according to claim 1, characterized in that: 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×tan(FOV / 2))<1.

1.

4. The optical lens according to claim 1, characterized in that: The real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.65 <IH / f<0.7。 5. The optical lens according to claim 1, characterized in that: 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: 50<180°×TTL / IH / FOV<58.

6. The optical lens according to claim 1, characterized in that: 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.

7. The optical lens according to claim 1, characterized in that: A curvature radius R9 of the object side surface of the fifth lens and a curvature radius R10 of the image side surface of the fifth lens satisfy: 0.8<(R9-R10) / (R9+R10)<0.

95.

8. The optical lens according to claim 1, characterized in that: A curvature radius R11 of the object side surface of the sixth lens and a curvature radius R12 of the image side surface of the sixth lens satisfy: 0.02<(R11-R12) / (R11+R12)<0.

45.

9. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: f1 / f<-6.

10. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: f2 / f<-4.

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