Optical lens

Abstract

The present invention provides an optical lens, which has six lenses in total, and includes in order from the object side to the imaging surface along the optical axis: a first lens with positive focal power; a second lens with negative focal power, whose object side surface is concave and whose image side surface is convex; a third lens with positive focal power, whose object side surface and image side surface are both convex; a fourth lens with positive focal power, whose object side surface is convex and whose image side surface is concave; a fifth lens with negative focal power, whose object side surface is convex and whose image side surface is concave; and a sixth lens with positive focal power. The optical lens provided by the present invention uses six lenses with specific focal powers, and through specific surface shape matching and reasonable focal power distribution, it can 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.

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 positive optical power;

[0008] The second lens has a negative optical power, its object side surface is concave, and its image side surface is convex;

[0009] The third lens has positive refractive power, and both the object side surface and the image side surface are convex;

[0010] a fourth lens having positive refractive power, whose object-side surface is convex and whose image-side surface is concave;

[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 has positive refractive power.

[0013] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.3 <TTL / f<2.5。

[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: 0.98<(IH / 2) / (f×tan(FOV / 2))<1.05.

[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: 0.6 <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: 70<180°×TTL / IH / FOV<73.

[0017] 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: -0.85<(R3-R4) / (R3+R4)<-0.55.

[0018] 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: -0.85<(R7-R8) / (R7+R8)<-0.65.

[0019] 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: 0.65<(R9-R10) / (R9+R10)<0.95.

[0020] Further preferably, a curvature radius R1 of the object side surface of the first lens and a curvature radius R2 of the image side surface of the first lens satisfy: |(R1+R2) / (R1-R2)|>2.

[0021] 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: |(R11+R12) / (R11-R12)|>2.8.

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

[0026] Figure 3 Graph 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] Fig.17 Schematic diagram of the structure of the optical lens in Example 5 of the present invention.

[0041] Fig.184 is a field curvature curve diagram of the optical lens in Example 5 of the present invention.

[0042] Fig.19 4 is a graph showing the F-Tan (Theta) distortion curve of the optical lens in Example 5 of the present invention.

[0043] Fig. 20 This is the MTF curve diagram of the optical lens in Example 5 of the present invention.

[0044] Fig.21 Schematic diagram of the structure of the optical lens in Example 6 of the present invention.

[0045] Fig. 22 4 is a field curvature curve diagram of the optical lens in Example 6 of the present invention.

[0046] Fig.23 4 is a graph showing the F-Tan (Theta) distortion curve of the optical lens in Example 6 of the present invention.

[0047] Fig.24 This is the MTF curve diagram of the optical lens in Example 6 of the present invention.

[0048] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0056] The optical lens provided by the embodiment of the present invention comprises six lenses, which are a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in order from the object side to the imaging surface along the optical axis.

[0057] In some embodiments, the first lens may have positive 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 negative power, its object side surface is concave, and its image side surface is convex; the third lens may have positive power, and both its object side surface and image side surface are convex. The fourth lens may have positive power, its object side surface is convex, and its image side surface is concave. The fifth lens may have negative power, its object side surface is convex, and its image side surface is concave. The sixth lens may have positive power, its object side surface may be concave or convex, and its image side surface may be concave or convex.

[0058] 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.

[0059] 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.

[0060] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.3 < TTL / f < 2.5. Satisfying the above range is beneficial to limiting the total length of the lens and achieving miniaturization.

[0061] 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: 0.98 < (IH / 2) / (f×tan(FOV / 2)) < 1.05. Satisfying the above range can control the optical lens to have small distortion and improve the imaging quality of the optical lens.

[0062] 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: 0.6 < IH / f < 0.7. Satisfying the above range and controlling the image height and focal length of the optical lens within a reasonable range helps the optical lens to have the characteristic of a large image plane and improve the imaging quality.

[0063] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.22 < BFL / f < 0.4. Satisfying the above range limits the optical lens to have an appropriate back focus, facilitates the reasonable arrangement of the positions of the lenses, and at the same time reduces the processing and assembly difficulty.

[0064] In some embodiments, the total 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: 70 < 180°×TTL / IH / FOV < 73. Satisfying the above range limits the length of the optical lens under the condition of the same imaging area and the same field of view, and realizes the miniaturization of the optical lens.

[0065] In some embodiments, the total 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: 0.5 < ∑CT / TTL < 0.7. Satisfying the above range and reasonably configuring the total optical length of the optical lens and the sum of the thicknesses of the lenses helps to achieve the high-pixel characteristic and improve the imaging quality of the optical lens.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: f1 / f > 3.5. Meeting the above range has the effect of converging light rays and can reduce the front aperture.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: f2 / f < -0.9. Meeting the above range has the effect of diverging light rays. At the same field of view angle, it further diverges the light rays emerging from the image side of the first lens, can disperse the central light rays and edge light rays of each field of view, and enables the rear optical system to have a larger light receiving surface to receive the light rays emerging from the image side of the second lens, achieving a larger light input amount and being beneficial to increasing the relative illuminance.

[0068] 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 < 1.1. Meeting the above range defines that the third lens has an appropriate positive optical power and has the effect of converging light rays. When paired with the negative optical power of the second lens, it can further converge the light rays passing through the second lens, suppress the height of the peripheral light rays, and is beneficial to reducing the aperture of the rear lens.

[0069] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.1 < f4 / f < 1.4. Meeting the above range defines that the fourth lens has an appropriate positive optical power, which is beneficial to light ray convergence. And the cooperation of the fourth lens with positive optical power and the fifth lens with negative optical power can adjust the optical path difference between different fields of view, improve the resolution, is beneficial to making the light rays enter the rear lens smoothly, and further can reduce the field curvature and correct the off-axis aberration of the optical lens.

[0070] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: f5 / f < -1. Meeting the above range defines that the fifth lens has a negative optical power, can diverge the light rays emerging from the fourth lens, makes the light rays in the edge field of view show an upward trend, is beneficial to the image points on the imaging surface being away from the optical axis, is beneficial to achieving the effect of matching with a large chip, obtaining a larger picture, and can cooperate with the fourth lens with positive optical power to effectively eliminate aberrations and improve the resolution ability of the optical lens.

[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: f6 / f>7.8. Meeting the above range and limiting the sixth lens to have a positive focal length is conducive to light convergence, making the light trend smoothly transition to the rear, reducing the height of the light incident to the rear, slowing down the upward trend of the light, avoiding the loss of light energy caused by the large angle between the main light of the chip and the large field of view when the light reaches the imaging surface, which is conducive to improving the illumination of the edge field of view and achieving a short total optical length.

[0072] In some embodiments, the radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: -0.85<(R3-R4) / (R3+R4)<-0.55. Meeting the above range, the light entering through the first lens can be smoothly collected at a smaller aperture; at the same time, the second lens is set as a meniscus lens bent toward the object side, which can smoothly converge the light passing through the first lens to the rear lens, reduce the front port diameter of the lens, reduce the volume, and facilitate the miniaturization of the optical lens and reduce the cost.

[0073] In some embodiments, the object side curvature radius R7 of the fourth lens and the image side curvature radius R8 of the fourth lens satisfy: -0.85<(R7-R8) / (R7+R8)<-0.65. When the above range is met, light can be converged, the aperture of the rear lens can be reduced, and the light collected by the front lens can be smoothly transmitted to the rear lens.

[0074] In some embodiments, the object side curvature radius R9 of the fifth lens and the image side curvature radius R10 of the fifth lens satisfy: 0.65<(R9-R10) / (R9+R10)<0.95. When the above range is met, the light entering through the fourth lens can be collected, so that the light trend transitions smoothly, which is conducive to reducing the sensitivity of the optical lens and improving the imaging quality of the optical lens.

[0075] In some embodiments, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: |(R1+R2) / (R1-R2)|>2. When the above range is met, the object side surface and the image side surface can be close to a concentric circle structure, reducing the ability of the first lens to converge light and playing a role in smooth transition of light.

[0076] In some embodiments, the object side surface curvature radius R11 of the sixth lens and the image side surface curvature radius R12 of the sixth lens satisfy: |(R11+R12) / (R11-R12)|>2.8. When the above range is met, the object side surface and the image side surface can be close to a concentric circle structure, reducing the ability of the sixth lens to converge light and playing a role in smooth transition of light.

[0077] In some embodiments, the optical lens satisfies the following conditional expressions: 14mm < f < 15mm; 30° < FOV < 40°; 9mm < EPD < 10mm; 34mm < TTL < 36mm; 1.5 < Fno < 1.8; 9mm < IH < 10mm; 11° < CRA < 19°; 3mm < BFL < 6mm. 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 total 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 chief 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 ranges, 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.

[0078] In some embodiments, the lens material of 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.

[0079] 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, in the present invention, the first lens, the second lens, the fourth lens, and the fifth lens adopt spherical lenses, and the third lens and the sixth lens adopt aspherical lenses.

[0080] 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 equations:

[0081] ;

[0082] where z is the distance between the surface and the vertex of the surface in the optical axis direction, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the conic coefficient, and B, C, D, E, and F are the surface coefficients of the fourth order, sixth order, eighth order, tenth order, and twelfth order respectively.

[0083] 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.

[0084] Example 1

[0085] 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.

[0086] The first lens L1 has positive refractive power, its object side surface S1 is concave, and its image side surface S2 is convex;

[0087] The second lens L2 has negative refractive power, its object side surface S3 is concave, and its image side surface S4 is convex;

[0088] The third lens L3 has positive refractive power, and its object-side surface S5 and image-side surface S6 are both convex;

[0089] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is concave;

[0090] The fifth lens L5 has negative refractive power, its object-side surface S9 is convex, and its image-side surface S10 is concave;

[0091] The sixth lens L6 has positive refractive power, its object-side surface S11 is concave, and its image-side surface S12 is convex;

[0092] The object side surface S13 and the image side surface S14 of the filter G1 are both planes;

[0093] The imaging surface S15 is a plane.

[0094] The third lens L3 and the sixth lens L6 are glass aspherical lenses, and the first lens L1, the second lens L2, the fourth lens L4 and the fifth lens L5 are glass spherical lenses.

[0095] The relevant parameters of each lens in the optical lens in Example 1 are shown in Table 1-1.

[0096] Table 1-1

[0097]

[0098] The surface parameters of the aspherical lens of the optical lens in Example 1 are shown in Table 1-2.

[0099] Table 1-2

[0100]

[0101] 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.

[0102] 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 ±0.06mm, indicating that the optical lens can correct the field curvature well.

[0103] 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 ±2%, indicating that the optical lens can correct the distortion well.

[0104] 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 0.2 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.

[0105] Example 2

[0106] 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, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0107] The relevant parameters of each lens in the optical lens in Example 2 are shown in Table 2-1.

[0108] Table 2-1

[0109]

[0110] The surface parameters of the aspherical lens of the optical lens in Example 2 are shown in Table 2-2.

[0111] Table 2-2

[0112]

[0113] 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.

[0114] from Figure 6 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.1mm, indicating that the optical lens can correct the field curvature well.

[0115] from Figure 7 It can be seen that the distortion of the optical lens is controlled within ±2%, which means that the optical lens can correct the distortion well.

[0116] 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.

[0117] Example 3

[0118] See also Fig. 9 , which is a schematic diagram of the structure of the optical lens provided in Example 3 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the object-side surface S11 of the sixth lens L6 is a convex surface; the image-side surface S12 of the sixth lens L6 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0119] The relevant parameters of each lens in the optical lens in Example 3 are shown in Table 3-1.

[0120] Table 3-1

[0121]

[0122] The surface parameters of the aspherical lens of the optical lens in Example 3 are shown in Table 3-2.

[0123] Table 3-2

[0124]

[0125] 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.

[0126] from Fig.10 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.1mm, indicating that the optical lens can correct the field curvature well.

[0127] from Fig.11 It can be seen that the distortion of the optical lens is controlled within ±2%, which means that the optical lens can correct the distortion well.

[0128] from Fig.12 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.

[0129] Example 4

[0130] See also Fig.13 , which is a schematic diagram of the structure of an optical lens provided in Example 4 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the object-side surface S11 of the sixth lens L6 is a convex surface; the image-side surface S12 of the sixth lens L6 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0131] The relevant parameters of each lens in the optical lens in Example 4 are shown in Table 4-1.

[0132] Table 4-1

[0133]

[0134] The surface parameters of the aspherical lens of the optical lens in Example 4 are shown in Table 4-2.

[0135] Table 4-2

[0136]

[0137] 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.

[0138] from Fig.14It 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.

[0139] from Fig.15 It can be seen that the distortion of the optical lens is controlled within ±4%, which means that the optical lens can correct the distortion well.

[0140] 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.

[0141] Example 5

[0142] See also Fig.17 , which is a schematic diagram of the structure of the optical lens provided in Example 5 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.

[0143] The relevant parameters of each lens in the optical lens in Example 5 are shown in Table 5-1.

[0144] Table 5-1

[0145]

[0146] The surface parameters of the aspherical lens of the optical lens in Example 5 are shown in Table 5-2.

[0147] Table 5-2

[0148]

[0149] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens are respectively as follows: Fig.18 , Fig.19 , Fig. 20 shown.

[0150] from Fig.18 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.

[0151] from Fig.19 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.

[0152] from Fig. 20It can be seen that the MTF value of this embodiment is above 0.25 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.

[0153] Example 6

[0154] See also Fig.21 , which is a schematic diagram of the structure of an optical lens provided in Example 6 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 S11 of the sixth lens L6 is a convex surface; the image-side surface S12 of the sixth lens L6 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0155] The relevant parameters of each lens in the optical lens in Example 6 are shown in Table 6-1.

[0156] Table 6-1

[0157]

[0158] The surface parameters of the aspherical lens of the optical lens in Example 6 are shown in Table 6-2.

[0159] Table 6-2

[0160]

[0161] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens are respectively as follows: Fig. 22 , Fig.23 , Fig.24 shown.

[0162] from Fig. 22 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.

[0163] from Fig.23 It can be seen that the distortion of the optical lens is controlled within ±2%, which means that the optical lens can correct the distortion well.

[0164] from Fig.24 It can be seen that the MTF value of this embodiment is above 0.45 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.

[0165] Please refer to Table 7, 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.

[0166] Table 7

[0167]

[0168] 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.

[0169] 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.

[0170] 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: It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with a positive optical power; A second lens with a negative optical power, whose object side is concave and whose image side is convex; A third lens with a positive optical power, whose object side and image side are both convex; A fourth lens with a positive optical power, whose object side is convex and whose image side is concave; A fifth lens with a negative optical power, whose object side is convex and whose image side is concave; A sixth lens with a positive optical power; The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.3 < TTL / f < 2.5; 14mm < f < 15mm, where f represents the effective focal length of the optical lens; 9mm < IH < 10mm, where IH represents the true image height corresponding to the maximum field of view angle of the optical lens.

2. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens, and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.98 < (IH / 2) / (f×tan(FOV / 2)) < 1.

05.

3. The optical lens according to claim 1, characterized in that: The true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.6 < IH / f < 0.

7.

4. The optical lens according to claim 1, characterized in that: The total optical length TTL of the optical lens, the maximum field of view angle FOV of the optical lens, and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 70 < 180°×TTL / IH / FOV < 73.

5. The optical lens according to claim 1, characterized in that: The curvature radius R3 of the object side of the second lens and the curvature radius R4 of the image side of the second lens satisfy: -0.85 < (R3 - R4) / (R3 + R4) < -0.

55.

6. The optical lens according to claim 1, characterized in that: The curvature radius R7 of the object side of the fourth lens and the curvature radius R8 of the image side of the fourth lens satisfy: -0.85 < (R7 - R8) / (R7 + R8) < -0.

65.

7. The optical lens according to claim 1, characterized in that: 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: 0.65 < (R9 - R10) / (R9 + R10) < 0.

95.

8. The optical lens according to claim 1, characterized in that: The curvature radius R1 of the object side of the first lens and the curvature radius R2 of the image side of the first lens satisfy: 13.25 ≥ |(R1 + R2) / (R1 - R2)| > 2.

9. The optical lens according to claim 1, characterized in that: The curvature radius R11 of the object side of the sixth lens and the curvature radius R12 of the image side of the sixth lens satisfy: 20.20 ≥ |(R11 + R12) / (R11 - R12)| > 2.8.

Images