Optical lens

Abstract

The application provides an optical lens, which comprises seven lenses in sequence along an optical axis from an object side to an imaging surface, and the seven lenses comprise: a first lens with positive refractive power, wherein the object side surface of the first lens is a concave surface, and the image side surface of the first lens is a convex surface; a second lens with positive refractive power; a third lens with negative refractive power, wherein the object side surface of the third lens is a concave surface; a fourth lens with positive refractive power, wherein the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; a fifth lens with negative refractive power, wherein the object side surface of the fifth lens is a concave surface; a sixth lens with positive refractive power, wherein the object side surface of the sixth lens is a convex surface; and a seventh lens with negative refractive power, wherein the object side surface of the seventh lens is a concave surface; wherein 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 the condition: |(R1-R2) / (R1+R2)|<0.6. The optical lens provided by the application has one or more advantages of long focal length, large aperture, high imaging quality and the like through specific surface shape matching and reasonable refractive power distribution.

Description

Technical Field

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

[0002] As people's demands for driving experience continue to increase, automotive optical lenses are being used more and more in intelligent driving, and the status of automotive optical lenses in the automotive industry is constantly rising.

[0003] Advanced Driver Assistance Systems (ADAS) play a crucial role in intelligent driving. They use various lenses and sensors to collect environmental information to ensure driver safety. Existing ADAS lenses not only require a slim and compact design with high pixel count and high resolution, but also need to produce clear images in low-light conditions. Therefore, it is necessary to develop an optical lens with excellent imaging performance. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an optical lens with the advantage of excellent image quality.

[0005] The technical solution adopted in this invention is as follows:

[0006] An optical lens comprises seven lenses, arranged sequentially along the optical axis from the object side to the imaging plane:

[0007] The first lens with positive optical power has a concave object side and a convex image side.

[0008] A second lens with positive optical power;

[0009] A third lens with negative optical power has a concave object side.

[0010] The fourth lens with positive optical power has a convex object-side surface and a convex image-side surface.

[0011] The fifth lens has negative optical power and its object side is concave.

[0012] The sixth lens has positive optical power and its object side is convex.

[0013] The seventh lens has negative optical power and its object side is concave.

[0014] Wherein, the object-side radius of curvature R1 of the first lens and the image-side radius of curvature R2 of the first lens satisfy: |(R1-R2) / (R1+R2)|<0.6.

[0015] 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 < 3; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 4 < TTL / IH < 5.

[0016] Further preferably, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 17° < FOV / Fno < 18°; the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 0.9 < IH / EPD < 1.2.

[0017] Further preferably, the half-aperture d1 of the object side of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 5.5 < d1 / (IH / 2) / tan(FOV / 2) < 8; the combined focal length f4567 of the fourth, fifth, sixth, and seventh lenses and the effective focal length f of the optical lens satisfy: 0.5 < f4567 / f < 1.6.

[0018] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 3.8 < f1 / f < 60; the curvature radius R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: -8 < R1 / f < -1.2; the curvature radius R2 of the image side of the first lens and the effective focal length f of the optical lens satisfy: -3 < R2 / f < -1.2.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.2 < f2 / f < 9.5; the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -19 < f3 / f < -0.6.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.4 < f4 / f < 0.8; the curvature radius R7 of the object side of the fourth lens and the effective focal length f of the optical lens satisfy: 0.5 < R7 / f < 0.8; the curvature radius R8 of the image side of the fourth lens and the effective focal length f of the optical lens satisfy: -1.2 < R8 / f < -0.4.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.9 < f5 / f < -0.9; the curvature radius R9 of the object side of the fifth lens and the effective focal length f of the optical lens satisfy: -1.2 < R9 / f < -0.4.

[0022] More preferably, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 0.5 < f6 / f < 3; the radius of curvature R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 0.7 < R11 / f < 1.4.

[0023] More preferably, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.2 < f7 / f < -0.4; the radius of curvature R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -0.9 < R13 / f < -0.4.

[0024] The optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberrations, improve the imaging quality of the optical lens, and endow the lens with one or more advantages such as long focal length, large aperture, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0026] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 2 is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 3 is an F-Tan(Theta) distortion curve of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 4 is a MTF curve diagram of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 5 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 6 is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 7 is an F-Tan(Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 8 is a MTF curve diagram of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 9 is a schematic structural diagram of the optical lens in Embodiment 3 of the present invention.

[0035] Figure 10 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0036] Figure 11 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.

[0037] Figure 12 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 13 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0039] Figure 14 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0040] Figure 15 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 4 of the present invention.

[0041] Figure 16 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0042] Figure 17 This is a schematic diagram of the optical lens structure in Embodiment 5 of the present invention.

[0043] Figure 18 This is a field curvature curve diagram of the optical lens in Embodiment 5 of the present invention.

[0044] Figure 19 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 5 of the present invention.

[0045] Figure 20 This is the MTF curve of the optical lens in Embodiment 5 of the present invention.

[0046] Figure 21 This is a schematic diagram of the optical lens in Embodiment 6 of the present invention.

[0047] Figure 22 This is a field curvature curve diagram of the optical lens in Embodiment 6 of the present invention.

[0048] Figure 23 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 6 of the present invention.

[0049] Figure 24 This is the MTF curve of the optical lens in Embodiment 6 of the present invention.

[0050] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0051] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this 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.

[0052] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0053] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0054] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity 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 location of the concaveness 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 subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0055] It should also be understood that the terms "comprising," "including," "having," "containing," 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. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0056] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0057] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0058] The optical lens provided in this embodiment of the invention consists of seven lenses, which are arranged sequentially along the optical axis from the object side to the imaging plane as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

[0059] The first lens may have positive optical power, with a concave object-side surface and a convex image-side surface. The second lens may have positive optical power, with both its object-side and image-side surfaces being either concave or convex. The third lens may have negative optical power, with both its object-side and image-side surfaces being either concave or convex. The fourth lens may have positive optical power, with both its object-side and image-side surfaces being convex. The fifth lens may have negative optical power, with both its object-side and image-side surfaces being either concave or convex. The sixth lens may have positive optical power, with both its object-side and image-side surfaces being either concave or convex. The seventh lens may have negative optical power, with both its object-side and image-side surfaces being either concave or convex.

[0060] In some embodiments, the optical lens may also include an aperture stop, which may be located between the third and fourth lenses. It is understood that the aperture stop is used to limit the amount of light entering the lens, thereby changing the brightness of the image. Furthermore, when the aperture stop is located between the third and fourth lenses, it can rationally allocate the functions of the first to seventh lenses. For example, the first, second, and third lenses can be used to receive light to a greater extent, while the fourth to seventh lenses can be used to correct aberrations, which is beneficial for balancing the overall structure of the optical system. In addition, when the aperture stop is located between the third and fourth lenses, it facilitates the correction of aperture aberrations.

[0061] In some embodiments, the optical lens may further include a filter and a protective glass, which are sequentially disposed between the seventh lens and the imaging plane along the optical axis. The filter is used to filter out interfering light, preventing it from reaching the imaging plane of the optical lens and affecting normal imaging. The protective glass protects the optical lens, preventing damage to the image sensor, and improves the lens's shock and scratch resistance, while having almost no impact on the image quality.

[0062] In some embodiments, the fourth and fifth lenses can be cemented together to form a cemented lens, which can effectively correct chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberrations of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0063] 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)| < 0.6. Meeting the above range, using a meniscus lens for the first lens can further control the smoothness of the light path, make the light more concentrated, further control the light direction, reduce the back focal length, improve the imaging quality, increase the light utilization rate, and at the same time reduce the spherical aberration of the optical lens, thereby improving the imaging quality of the optical lens. More specifically, -0.03 < (R1 - R2) / (R1 + R2) < 0.53.

[0064] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.3 < TTL / f < 3. Meeting the above range can effectively limit the length of the lens, which is beneficial to the miniaturization of the optical lens. More specifically, 2.54 < TTL / f < 2.81.

[0065] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 4 < TTL / IH < 5. Meeting the above range ensures that, with the same overall length of the lens, it has a larger image plane, can match a larger-sized imaging chip to achieve high-definition imaging, and better achieves the balance between a small overall length and a large image plane of the lens. More specifically, 4.46 < TTL / IH < 4.75.

[0066] In some embodiments, the maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 17° < FOV / Fno < 18°. Meeting the above range limits the optical lens to have an appropriate field angle and f-number, can collect light at a large angle, and obtain good imaging quality. More specifically, 17.77° < FOV / Fno < 17.9°.

[0067] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 0.9 < IH / EPD < 1.2. Meeting the above range can increase the width of the light beam entering the optical lens, improve the brightness at the image plane of the optical lens, and avoid the generation of vignetting. More specifically, 0.99 < IH / EPD < 1.13.

[0068] In some embodiments, the clear aperture radius d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 5.5 < d1 / (IH / 2) / tan(FOV / 2) < 8. Satisfying the above range can achieve a small front aperture while meeting the requirements of a large field angle and a large image plane for the optical lens. More specifically, 5.95 < d1 / (IH / 2) / tan(FOV / 2) < 7.71.

[0069] In some embodiments, the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens and the effective focal length f of the optical lens satisfy: 0.5 < f4567 / f < 1.6. Satisfying the above range is beneficial to balancing various aberrations of the system and improving the overall imaging quality by reasonably setting the focal length of the lens group behind the aperture stop. More specifically, 0.55 < f4567 / f < 1.53.

[0070] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 3.8 < f1 / f < 60; the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -8 < R1 / f < -1.2; the curvature radius R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: -3 < R2 / f < -1.2. Satisfying the above range, by setting the first lens to have a positive refractive power, it has the effect of converging light rays, reducing the height of peripheral light rays, which is beneficial to reducing the aperture of the rear lens. More specifically, 4.11 < f1 / f < 57.19; -7.51 < R1 / f < -1.28; -2.89 < R2 / f < -1.26.

[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.2 < f2 / f < 9.5. Satisfying the above range limits the second lens to have an appropriate positive optical power, further converging light rays, and being able to share the positive optical power at the front end of the optical lens, thus being beneficial to avoiding excessive light ray deflection caused by overly concentrated optical power of the first lens and reducing the difficulty of aberration correction. More specifically, 1.28 < f2 / f < 8.94.

[0072] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -19 < f3 / f < -0.6; the curvature radius R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: -2.9 < R5 / f < -0.6. Satisfying the above range makes the third lens have a negative optical power and the object side surface is concave, having the effect of diverging light rays, being able to disperse the central light rays and marginal light rays of each field, and being able to correct the aberrations generated by the front lens. More specifically, -18.01 < f3 / f < -0.66; -2.64 < R5 / f < -0.67.

[0073] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.4 < f4 / f < 0.8; the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 0.5 < R7 / f < 0.8; the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -1.2 < R8 / f < -0.4; the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: |(R7 + R8) / (R7 - R8)| < 0.4. Satisfying the above ranges defines that the fourth lens has an appropriate positive optical power and surface shape, and the light rays are further converged. And gluing the fourth lens with positive optical power and the fifth lens with negative optical power is beneficial for the light rays to enter the rear lens gently, can adjust the optical path difference between different fields of view, and improve the resolution. More specifically, 0.44 < f4 / f < 0.78; 0.53 < R7 / f < 0.73; -1.13 < R8 / f < -0.4; -0.24 < (R7 + R8) / (R7 - R8) < 0.26.

[0074] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.9 < f5 / f < -0.9; the radius of curvature R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -1.2 < R9 / f < -0.4. Satisfying the above ranges defines that the fifth lens has an appropriate negative optical power and the object side surface is concave, which can diverge the light rays emitted by the fourth lens, making the light rays in the edge field of view show an upward trend, beneficial for the image points on the imaging surface to be far from the optical axis, so as to be conducive to achieving the effect of matching with a large chip, obtaining a larger picture, effectively eliminating aberration, and improving the resolution ability of the optical lens. More specifically, -1.79 < f5 / f < -0.97; -1.13 < R9 / f < -0.4.

[0075] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 0.5 < f6 / f < 3; the radius of curvature R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 0.7 < R11 / f < 1.4. Satisfying the above ranges defines that the sixth lens has a positive optical power and the object side surface is convex, which is beneficial for the light rays to converge, makes the light ray trend transition smoothly to the rear, reduces the height of the light rays incident on the rear, slows down the upward trend of the light rays, avoids the light energy loss caused by the excessive main ray angle between the large field of view light rays and the chip when reaching the imaging surface, is beneficial for increasing the illuminance of the edge field of view, and is beneficial for achieving a short optical total length. More specifically, 0.59 < f6 / f < 2.78; 0.72 < R11 / f < 1.33.

[0076] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.2 < f7 / f < -0.4; the radius of curvature R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -0.9 < R13 / f < -0.4. Meeting the above ranges can effectively balance various aberrations generated by the front lens group, and at the same time is conducive to increasing the divergence degree of light, increasing the area of light entering the imaging surface, achieving large-format imaging of the lens, and improving the imaging quality of the optical lens. More specifically, -1.13 < f7 / f < -0.48; -0.89 < R13 / f < -0.45.

[0077] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.5 < IH / f < 0.65. Meeting the above ranges and controlling the image height and focal length of the optical lens within a reasonable range contribute to the optical lens having the characteristic of a large image surface and improving the imaging quality. More specifically, 0.54 < IH / f < 0.6.

[0078] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.24 < BFL / f < 0.39. Meeting the above ranges limits the optical lens to have 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.

[0079] 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 seventh lens along the optical axis satisfy: 0.53 < ∑CT / TTL < 0.73. Meeting the above ranges can effectively compress the overall length of the optical lens and is conducive to the structural design and production process of the optical lens at the same time.

[0080] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis and the effective focal length f of the optical lens satisfy: 1.44 < ΣCT / f < 1.91. Meeting the above ranges can effectively correct the field curvature and distortion of the optical lens and improve the imaging quality of the optical lens.

[0081] In some embodiments, the optical lens satisfies the following conditional expressions: 12 mm < f < 15 mm; 6.5 mm < EPD < 8 mm; 33 mm < TTL < 37 mm; 1.7 < Fno < 2; 17° < CRA < 26°; 3.4 mm < BFL < 5.2 mm; 31° < FOV < 35°; 7.5 mm < IH < 8 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, CRA represents the chief ray angle of incidence of the optical lens, BFL represents the back focal length of the optical lens, FOV represents the maximum field angle of the optical lens, and IH represents the true image height corresponding to the maximum field angle of the optical lens. Meeting the above ranges, the optical lens has at least one or more advantages such as a large image sensor format, a large aperture, and a long focal length characteristic. More specifically, 12.87 mm < f < 13.7 mm; 6.77 mm < EPD < 7.61 mm; 33.9 mm < TTL < 36.1 mm; 1.79 < Fno < 1.91; 17.54° < CRA < 21.37°; 3.43 mm < BFL < 5.15 mm; 31.9° < FOV < 34.1°; 7.59 mm < IH < 7.69 mm.

[0082] 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, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present 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.

[0083] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better achieving the miniaturization of the lens. More specifically, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens of the present invention adopt spherical lenses.

[0084] The present invention will be further described in multiple embodiments below. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are somewhat different. For specific differences, refer to the parameter tables of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any other changes, substitutions, combinations, or simplifications made without departing 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.

[0085] Example 1

[0086] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1, and a protective glass G2.

[0087] Among them, the first lens L1 has positive optical power, its object side S1 is concave, and its image side S2 is convex.

[0088] The second lens L2 has positive optical power, its object side S3 is concave, and its image side S4 is convex.

[0089] The third lens L3 has negative optical power, its object side S5 is concave, and its image side S6 is convex.

[0090] The fourth lens L4 has positive optical power, its object side S7 is convex, and its image side is convex.

[0091] The fifth lens L5 has negative optical power, its object side is concave, and its image side S9 is convex.

[0092] The fourth lens L4 and the fifth lens L5 form a cemented lens group with positive optical power, that is, the cemented surface of the image side of the fourth lens L4 and the object side of the fifth lens L5 is S8.

[0093] The sixth lens L6 has positive optical power, its object side S10 is convex, and its image side S11 is concave.

[0094] The seventh lens L7 has negative optical power, its object side S12 is concave, and its image side S13 is convex.

[0095] The object-side surface S14 and the image-side surface S15 of filter G1 are both planar.

[0096] The object side S16 and the image side S17 of the protective glass G2 are both flat.

[0097] The imaging plane S18 is a plane.

[0098] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are glass spherical lenses.

[0099] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1.

[0100] Table 1

[0101]

[0102]

[0103] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 As shown.

[0104] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.02 mm to 0.05 mm, indicating that the optical lens can effectively correct the field curvature.

[0105] Figure 3 The F-Tan (Theta) distortion curves for Example 1 are shown, representing the F-Tan (Theta) distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tan (Theta) distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tan (Theta) distortion of the optical lens is controlled within -3% to 0, indicating that the optical lens can effectively correct distortion.

[0106] Figure 4 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.38 throughout the entire field of view. Within the range of 0–120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0107] Example 2

[0108] Please see Figure 5 The figure shows a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the object side S3 of the second lens L2 is a convex surface; the image side S4 of the second lens L2 is a concave surface; the image side S6 of the third lens L3 is a concave surface; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0109] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2.

[0110] Table 2

[0111]

[0112] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 As shown. From Figure 6 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.05mm to 0.05mm, indicating that the optical lens can effectively correct field curvature. From Figure 7 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -0.5% to 0, indicating that the optical lens can effectively correct distortion. From Figure 8 As can be seen, the MTF value of this embodiment is above 0.4 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.

[0113] Example 3

[0114] Please see Figure 9 The figure shows a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side surface S3 of the second lens L2 is a convex surface; the image side surface S6 of the third lens L3 is a concave surface; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0115] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3.

[0116] Table 3

[0117]

[0118] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 300 are respectively as follows: Figure 10 , Figure 11 , Figure 12 As shown. From Figure 10 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.04mm to 0.05mm, indicating that the optical lens can effectively correct field curvature. From Figure 11As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -4% to 0, indicating that the optical lens can effectively correct distortion. From Figure 12 As can be seen, the MTF value of this embodiment is above 0.3 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.

[0119] Example 4

[0120] Please see Figure 13 The figure shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side surface S9 of the fifth lens L5 is concave; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0121] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4.

[0122] Table 4

[0123]

[0124] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 400 are respectively as follows: Figure 14 , Figure 15 , Figure 16 As shown. From Figure 14 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.01mm to 0.05mm, indicating that the optical lens can effectively correct field curvature. Figure 15 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -2% to 0, indicating that the optical lens can effectively correct distortion. From Figure 16 As can be seen, the MTF value of this embodiment is above 0.3 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.

[0125] Example 5

[0126] Please see Figure 17The diagram shows a schematic of the structure of the optical lens 500 provided in Embodiment 5 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the object-side surface S3 of the second lens L2 is convex; the image-side surface S4 of the second lens L2 is concave; the image-side surface S6 of the third lens L3 is concave; the image-side surface S11 of the sixth lens L6 is convex; the image-side surface S13 of the seventh lens L7 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0127] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5.

[0128] Table 5

[0129]

[0130] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 500 are respectively as follows: Figure 18 , Figure 19 , Figure 20 As shown. From Figure 18 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.01mm to 0.05mm, indicating that the optical lens can effectively correct field curvature. Figure 19 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -1% to 0, indicating that the optical lens can effectively correct distortion. From Figure 20 As can be seen, the MTF value of this embodiment is above 0.5 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, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0131] Example 6

[0132] Please see Figure 21 The figure shows a schematic diagram of the structure of the optical lens 600 provided in Embodiment 6 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the object side S3 of the second lens L2 is a convex surface; the image side S6 of the third lens L3 is a concave surface; the image side S11 of the sixth lens L6 is a convex surface; the image side S13 of the seventh lens L7 is a concave surface; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0133] The relevant parameters of each lens in the optical lens 600 in Example 6 are shown in Table 6.

[0134] Table 6

[0135]

[0136] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 600 are respectively as follows: Figure 22 , Figure 23 , Figure 24 As shown. From Figure 22 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.02mm to 0.04mm, indicating that the optical lens can effectively correct field curvature. From Figure 23 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -3% to 0, indicating that the optical lens can effectively correct distortion. From Figure 24 As can be seen, the MTF value of this embodiment is above 0.3 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.

[0137] Please refer to Table 7 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.

[0138] Table 7

[0139] Parameters and conditional expressions Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 f(mm) 13.59 13.33 12.88 13.60 13.55 13.69 EPD (mm) 7.55 7.41 6.78 7.55 7.53 7.60 TTL(mm) 36.00 34.00 36.00 36.00 34.50 36.00 Fno 1.80 1.80 1.90 1.80 1.80 1.80 CRA(°) 21.00 19.42 21.36 18.58 21.29 17.55 BFL (mm) 3.44 3.44 3.44 3.44 5.14 4.15 FOV (°) 32.00 32.00 34.00 32.00 32.00 32.00 IH(mm) 7.60 7.60 7.60 7.60 7.68 7.60 TTL / f 2.65 2.55 2.80 2.65 2.55 2.63 TTL / IH 4.74 4.47 4.74 4.74 4.49 4.74 FOV / Fno(°) 17.78 17.78 17.89 17.78 17.78 17.78 IH / EPD 1.01 1.03 1.12 1.01 1.02 1.00 IH / f 0.56 0.57 0.59 0.56 0.57 0.55 BFL / f 0.25 0.26 0.27 0.25 0.38 0.30 ΣCT / TTL 0.63 0.57 0.54 0.61 0.66 0.72 ΣCT / f 1.68 1.45 1.52 1.61 1.67 1.90 d1 / (IH / 2) / tan(FOV / 2) 6.05 7.70 6.58 5.96 6.99 6.31 f1 / f 5.74 4.12 57.18 6.82 24.49 17.29 f2 / f 8.93 1.64 1.29 8.87 1.61 1.40 f3 / f -5.38 -0.76 -0.84 -18.00 -0.67 -0.72 f4 / f 0.70 0.53 0.54 0.77 0.45 0.52 f5 / f -1.25 -1.78 -1.65 -1.00 -1.14 -0.98 f6 / f 2.22 2.11 2.77 1.44 0.60 0.73 f7 / f -0.98 -0.96 -0.98 -1.12 -0.49 -0.59 f4567 / f 1.23 0.73 0.72 1.52 0.56 0.68 R1 / f -7.36 -7.50 -1.54 -3.68 -1.59 -1.29 R2 / f -2.88 -2.35 -1.59 -2.25 -1.57 -1.27 R5 / f -0.77 -2.63 -1.47 -0.68 -2.07 -1.94 R7 / f 0.70 0.72 0.69 0.70 0.54 0.70 R8 / f -0.81 -0.47 -0.51 -1.12 -0.41 -0.42 R9 / f -0.81 -0.47 -0.51 -1.12 -0.41 -0.42 R11 / f 1.32 1.23 0.94 1.14 0.73 1.26 R13 / f -0.47 -0.46 -0.47 -0.52 -0.88 -0.65 (R1-R2) / (R1+R2) 0.44 0.52 -0.02 0.24 0.01 0.01 (R7+R8) / (R7-R8) -0.08 0.21 0.15 -0.23 0.14 0.25

[0140] In summary, the optical lens provided by the present invention employs seven 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 telephoto, large aperture, and high imaging quality.

[0141] 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.

[0142] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens comprising seven lenses, characterized in that, It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with positive optical power, whose object side is concave and whose image side is convex; A second lens with positive optical power; A third lens with negative optical power, whose object side is concave; A fourth lens with positive optical power, whose object side is convex and whose image side is convex; A fifth lens with negative optical power, whose object side is concave; A sixth lens with positive optical power, whose object side is convex; A seventh lens with negative optical power, whose object side is concave; Wherein, 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: |(R1 - R2) / (R1 + R2)| < 0.6; the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.3 < TTL / f < 3; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 4 < TTL / IH < 5.

2. 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: -0.03 < (R1 - R2) / (R1 + R2) < 0.53; the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.54 < TTL / f < 2.81; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 4.46 < TTL / IH < 4.

75.

3. The optical lens according to claim 1, characterized in that, The maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 17° < FOV / Fno < 18°; the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 0.9 < IH / EPD < 1.

2.

4. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter d1 of the object side of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 5.5 < d1 / (IH / 2) / tan(FOV / 2) < 8; the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens and the effective focal length f of the optical lens satisfy: 0.5 < f4567 / f < 1.

6.

5. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 3.8 < f1 / f < 60; the curvature radius R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: -8 < R1 / f < -1.2; the curvature radius R2 of the image side of the first lens and the effective focal length f of the optical lens satisfy: -3 < R2 / f < -1.

2.

6. 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: 1.2 < f2 / f < 9.5; the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -19 < f3 / f < -0.

6.

7. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.4 < f4 / f < 0.8; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.5 < R7 / f < 0.8; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -1.2 < R8 / f < -0.

4.

8. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.9 < f5 / f < -0.9; the object-side curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: -1.2 < R9 / f < -0.

4.

9. The optical lens according to claim 1, characterized in that, The focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 0.5 < f6 / f < 3; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: 0.7 < R11 / f < 1.

4.

10. The optical lens according to claim 1, characterized in that, The focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.2 < f7 / f < -0.4; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -0.9 < R13 / f < -0.4.

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