Optical lens

Abstract

The invention provides an optical lens, which comprises seven lenses in total, and sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with positive focal power and a fifth lens with negative focal power from an object side to an imaging surface along an optical axis, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; 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; the fifth lens has positive focal power, and the image side surface of the fifth lens is a convex surface; the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a concave surface; and the seventh lens has negative focal power, and the image side surface of the seventh lens is a concave surface near the optical axis. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal power distribution, the imaging quality of the optical lens can be improved, and the optical lens has the advantage of excellent imaging quality.

Description

Technical Field

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

[0002] With the rapid development of drones, security, and automotive industries, the pursuit of imaging effects for their lenses has become more diversified. Currently, drones are developing rapidly, winning consumer favor with their unique high-altitude perspective and wide-angle shooting capabilities, leading to increasingly higher demands for their accompanying optical lenses. These lenses require not only high-definition image quality but also the ability to capture significant local details, ensuring that even from a high-altitude perspective, local details are rendered vividly, enabling the capture of close-up shots.

[0003] Therefore, it is necessary to develop an optical lens with a large image sensor, a large aperture, and good imaging performance to better meet market demands. 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] This invention provides an optical lens comprising seven lenses, arranged sequentially along the optical axis from the object side to the imaging plane: The first lens with negative optical power has a concave image-side surface. A second lens with positive optical power has a convex object-side surface and a concave image-side surface; A third lens with positive optical power has a convex object-side surface and a convex image-side surface. The fourth lens with positive optical power has a convex object-side surface and a convex image-side surface. The fifth lens with positive optical power has a convex image-side surface; The sixth lens has negative optical power, with both its object-side and image-side surfaces being concave. The seventh lens, which has negative optical power, has an image-side surface that is concave near the optical axis. Wherein, 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: 45°<(f×FOV) / IH<46°.

[0006] Further preferably, the total optical length (TTL) of the optical lens and the effective focal length (f) of the optical lens satisfy: 3.8 <TTL / f<3.9。

[0007] Further preferably, the back focal length (BFL) of the optical lens and the total optical length (TTL) of the optical lens satisfy: 0.08 <BFL / TTL<0.12。

[0008] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.4 <f1 / f<-2。

[0009] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.2 <f3 / f<1.4。

[0010] Further preferably, the object-side radius of curvature R13 of the seventh lens and the image-side radius of curvature R14 of the seventh lens satisfy: 0.9 < (R13 + R14) / (R13 - R14) < 5.2.

[0011] Further preferably, the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: 0.4 <f1 / f7<0.8。

[0012] Further preferably, the combined focal length f13 of the first lens, the second lens, and the third lens satisfies the following condition with respect to the effective focal length f of the optical lens: 1.3 <f13 / f<1.7。

[0013] Further preferably, the object-side light-transmitting half-aperture height SAG71 of the seventh lens, the image-side light-transmitting half-aperture height SAG72 of the seventh lens, and the center thickness CT7 of the seventh lens satisfy: -0.1<(SAG72-SAG71) / CT7<0.1.

[0014] Further preferably, the true image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4.5 <IH / EPD<4.6。

[0015] Compared with existing technologies, the optical lens provided by this invention uses 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. This gives the lens one or more advantages such as miniaturization, large aperture, large field of view, low distortion, high resolution, and high imaging quality. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0017] Figure 2 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 3 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 4 This is a relative illumination curve of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 5 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0021] Figure 6 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0022] Figure 7 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.

[0023] Figure 8 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0024] Figure 9 This is a relative illumination curve of the optical lens in Embodiment 2 of the present invention.

[0025] Figure 10 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0026] Figure 11 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0027] Figure 12 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.

[0028] Figure 13 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 14 This is a relative illumination curve of the optical lens in Embodiment 3 of the present invention.

[0030] Figure 15 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0031] Figure 16 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0032] Figure 17 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 4 of the present invention.

[0033] Figure 18 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0034] Figure 19 This is a relative illumination curve of the optical lens in Embodiment 4 of the present invention.

[0035] Figure 20 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0036] Figure 21 This is a schematic diagram of the optical lens structure in Embodiment 5 of the present invention.

[0037] Figure 22 This is an F-Tan (Theta) distortion curve of the optical lens in Embodiment 5 of the present invention.

[0038] Figure 23 This is a chromatic aberration curve of the optical lens in Embodiment 5 of the present invention.

[0039] Figure 24 This is a relative illumination curve of the optical lens in Embodiment 5 of the present invention.

[0040] Figure 25 This is the MTF curve of the optical lens in Embodiment 5 of the present invention.

[0041] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] The optical lens provided in this embodiment of the invention comprises seven lenses, which are arranged sequentially along the optical axis from the object side to the imaging plane as follows: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

[0050] In some embodiments, the first lens may have negative optical power, its object-side surface may be concave or convex, and its image-side surface may be concave. The second lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be concave. The third lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be convex. The fourth lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be convex. The fifth lens may have positive optical power, its object-side surface may be concave or convex, and its image-side surface may be convex. The sixth lens may have negative optical power, its object-side surface may be concave, and its image-side surface may be concave. The seventh lens may have negative optical power, its object-side surface may be concave or convex, and its image-side surface may be concave near the optical axis.

[0051] In some embodiments, the optical lens may further include an aperture, which may be located between the third lens and the fourth lens. It can be understood that the aperture is used to limit the amount of incident light to change the brightness of the image.

[0052] In some embodiments, the optical lens may further include a filter, which is disposed between the seventh lens and the imaging surface. The filter is used to filter out interfering light and prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0053] In some embodiments, the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens, and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 45° < (f × FOV) / IH < 46°. By satisfying the above conditional formula and reasonably restricting the relationship between the focal length, field angle, and image height of the optical lens, it is beneficial to achieve the balance between the field angle of the optical lens and the imaging surface, and better meet the usage requirements of high image quality and wide-angle shooting of the drone in outdoor environments.

[0054] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 3.8 < TTL / f < 3.9. By satisfying the above conditions, the length of the lens can be effectively restricted, which is beneficial to the miniaturization of the optical lens.

[0055] In some embodiments, the back focal length BFL of the optical lens and the overall optical length TTL of the optical lens satisfy: 0.08 < BFL / TTL < 0.12. By satisfying the above conditions and reasonably configuring the ratio of the back focal length of the optical lens to the overall optical length of the optical lens, it is beneficial to achieve a short back focus of the optical lens. Under the condition of ensuring sufficient space for the installation and focusing of optical elements, it is beneficial to the miniaturization of the optical lens.

[0056] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.4 < f1 / f < -2. By satisfying the above conditions, the first lens has a negative optical power, which can regulate the optical path, and by reasonably setting the focal length of the first lens, the field angle of the imaging system can be increased.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.2 < f3 / f < 1.4. The third lens that satisfies the above conditions can balance the optical power, control the back focus shift at high and low temperatures, and avoid defocusing.

[0058] In some embodiments, the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: 0.9 < (R13 + R14) / (R13 - R14) < 5.2. Meeting the above conditions and the shape of the seventh lens can be in the shape of M, which is beneficial to increasing the CRA and adapting to a specific sensor (such as IMX586).

[0059] In some embodiments, the focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: 0.4 < f1 / f7 < 0.8. Meeting the above conditions, by reasonably setting the focal length ratio of the first and last lenses, the lens can have a smaller head size while having a larger imaging surface, better meeting the balance of miniaturization and high pixel count.

[0060] In some embodiments, the combined focal length f13 of the first lens, the second lens and the third lens and the effective focal length f of the optical lens satisfy: 1.3 < f13 / f < 1.7. Meeting the above conditions, by reasonably setting the focal length of the lens group in front of the aperture, it is beneficial to reduce various aberrations generated by the front-end lens group and improve the overall imaging quality.

[0061] In some embodiments, the sagittal height SAG71 of the object side light-passing semi-aperture of the seventh lens, the sagittal height SAG72 of the image side light-passing semi-aperture of the seventh lens and the central thickness CT7 of the seventh lens satisfy: -0.1 < (SAG72 - SAG71) / CT7 < 0.1. Meeting the above conditions, by controlling the ratio of the difference in sagittal heights of the two sides of the seventh lens to its central thickness, it is convenient for the processing and forming of the seventh lens and is beneficial to reducing the sensitivity of the seventh lens, and further better balancing the relationship between the miniaturization of the optical lens and the relative illumination of the off-axis field of view.

[0062] 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: 4.5 < IH / EPD < 4.6. Meeting the above range enables the optical lens to satisfy a large image surface while also ensuring sufficient image surface brightness in the edge field of view, preventing the occurrence of vignetting phenomenon, thereby improving the imaging quality.

[0063] 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: 2.05 < IH / f < 2.1. Meeting the above conditions can achieve a larger field angle and imaging range, and can achieve the characteristics of a large image surface while ensuring the depth of field of the optical lens, thereby improving the imaging quality of the optical system.

[0064] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.8 < TTL / IH < 1.9. Meeting the above conditions can better achieve the miniaturization of the lens. At the same time, when ensuring the same total length of the lens, it has a larger image plane, can match a larger-sized imaging chip to achieve high-definition imaging.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.1 < f4 / f < 3.3. Meeting the above conditions, the fourth lens has a positive optical power, which can further focus light, optimize the imaging quality, and correct the remaining aberrations (such as distortion, chromatic aberration, etc.), thereby ensuring the imaging clarity and color restoration.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 2 < f5 / f < 2.7. Meeting the above conditions, by reasonably setting the proportion of the focal length of the fifth lens, it is beneficial to the smooth transition of light, facilitates the correction of astigmatism and field curvature, improves the imaging quality of the optical lens, and ensures the stability of the optical system.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1.8 < f6 / f < -1.3. Meeting the above conditions, by setting the sixth lens to have a negative optical power, the beam diameter can be reduced, and the size of the subsequent lens group can be reduced.

[0068] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -5.3 < f7 / f < -2.8. Meeting the above conditions, by setting the seventh lens to have a large negative optical power, the incident light can be diverged to a large extent, making the peripheral light and the central light turn upwards, reaching a higher imaging position, better achieving the large target surface imaging of the lens, and improving the imaging quality.

[0069] In some embodiments, 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: 1 < R3 / R4 < 1.3. By making the optical system meet the above relational expression, it is beneficial to the reasonable configuration of the ratio of the curvature radius of the object side of the second lens and the curvature radius of the image side of the second lens, controls the shape of the second lens, comprehensively balances the spherical aberration, chromatic aberration and field curvature of the optical system, reduces the risk of ghosting, improves the resolution ability of the optical system. At the same time, it is also beneficial to reduce the processing difficulty of the second lens.

[0070] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: -1.3 < R5 / R6 < -0.9; 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: -0.6 < R7 / R8 < -0.1. The surface shapes of the third lens and the fourth lens that meet the above conditions can balance the field curvature of the system and avoid deterioration of the edge image quality.

[0071] In some embodiments, the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: -0.6 < R11 / R12 < -0.3. The shape of the sixth lens is concave-concave. Meeting the above conditions enables the smooth transition of the converging light with a large front aperture, helps balance various aberrations, and reduces the lens sensitivity to a certain extent.

[0072] 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: 0.7 < (R1 + R2) / (R1 - R2) < 1.2. Meeting the above conditions and reasonably setting the radii of curvature of the object side surface and the image side surface of the first lens helps to achieve a larger field angle.

[0073] In some embodiments, 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: -0.8 < (R7 + R8) / (R7 - R8) < -0.2. Meeting the above range can reduce the light deflection angle, make the light trend smoother; at the same time, it can correct coma and field curvature, improve the flatness of imaging, and enhance the imaging quality of the optical lens.

[0074] In some embodiments, the radius of curvature R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 1 < R2 / f < 1.5. The image side surface of the first lens meeting the above conditions can reduce the incident angle of the light at the edge field of view, match the CRA tolerance of the microlens of the CMOS sensor, and avoid attenuation of the edge pixel signals.

[0075] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -0.1 < f1 / f2 < 0. When the optical power of the first lens is negative, it ensures that the optical power of the second lens is positive, thereby effectively controlling the volume of the optical system. The first lens and the second lens have opposite optical powers, enabling the optical system to have a better ability to balance aberrations.

[0076] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis respectively and the total optical length TTL of the optical lens satisfy: 0.3 < ∑CT / TTL < 0.7. Meeting the above conditions can effectively compress the total length of the optical lens, and is conducive to the structural design and production process of the optical lens.

[0077] In some embodiments, the edge thickness ET7 and the central thickness CT7 of the seventh lens satisfy: 0.9 < ET7 / CT7 < 1.1. Meeting the above conditions can keep the edge thickness and the centroid thickness of the seventh lens within a reasonable range, thereby ensuring that the seventh lens has good optical performance and molding yield, and at the same time ensuring good assembly stability of the seventh lens.

[0078] In some embodiments, the distance CT23 between the second lens and the third lens on the optical axis and the total optical length TTL of the optical lens satisfy: 0.05 < CT23 / TTL < 0.15. Meeting the above conditions is beneficial to reducing the sensitivity of the front and rear group air spacing tolerance and improving the lens production yield.

[0079] In some embodiments, the clear aperture radius DM11 of the object side of the first lens and the clear aperture radius DM72 of the image side of the seventh lens satisfy: 1.4 < DM11 / DM72 < 1.7. Meeting the above conditions, by reasonably setting the ratio of the apertures of the first and last lenses, the lens can have a smaller head size while having a larger imaging surface, and can better meet the balance of miniaturization and high pixels.

[0080] In some embodiments, the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens, and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 1.03 < (2×f×tan(FOV / 2)) / IH < 1.04. Meeting the above conditions indicates that the distortion of the optical lens < 4%, and the lens can have a smaller distortion value and provide a high-definition imaging effect.

[0081] In some embodiments, the chief ray angle of incidence CRA at the maximum image height of the optical lens satisfies: 33° < CRA < 38°. Meeting the above conditions and making the CRA angle larger can be adapted to a specific sensor (such as IMX586).

[0082] In some embodiments, the optical lens satisfies the conditional formula: 3.9mm < f < 4mm, 15mm < TTL < 16mm, 2.1 < Fno < 2.3, 8mm < IH < 8.5mm, 94° < FOV < 95°, where f represents the effective focal length of the optical lens, TTL represents the overall optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field angle of the optical lens, and FOV represents the maximum field angle of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention: has a relatively small overall optical length; has the characteristics of short focal length and wide angle. The depth of field of a short focal length lens is relatively deep, and both the front and back of the subject can remain relatively clear; can have a relatively large field angle, providing a wider shooting field of view for lenses in scenarios such as drones and capturing more image information; has a relatively large imaging surface, can be matched with a larger size chip to achieve high-definition imaging; has a relatively large aperture, and can achieve high-definition imaging even in complex light environments.

[0083] In some embodiments, all seven lenses in the optical lens can be made of plastic lenses or adopt a structure with a combination of glass and plastic materials. Preferably, the optical lens of the present invention adopts a structure of seven lenses with a combination of glass and plastic, which can improve the thermal stability performance. Specifically, the third lens can be made of a glass lens, and the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are all plastic lenses; adopting a glass-plastic hybrid structure can effectively reduce costs, correct aberrations, reduce the volume, and provide an optical lens product with higher cost performance.

[0084] 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 realizing the miniaturization of the lens. More specifically, the third lens in the optical lens provided by the present invention adopts a spherical lens; the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens all adopt aspherical lenses.

[0085] In each embodiment of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations: ; where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and B, C, D, E, F, G, H are the coefficients of the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order curved surfaces respectively.

[0086] The present invention will be further described below with reference to several 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 tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

[0087] Example 1 Please see Figure 1 The diagram shown is a structural schematic 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 S17, 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, and a filter G1. Among them, the first lens L1 has negative optical power, its object side S1 is concave near the optical axis, and its image side S2 is concave. The second lens L2 has positive optical power, its object side S3 is convex, and its image side S4 is concave. The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is convex. The fourth lens L4 has positive optical power, its object side S7 is convex, and its image side S8 is convex. The fifth lens L5 has positive optical power, its object side S9 is concave, and its image side S10 is convex. The sixth lens L6 has negative optical power, its object side S11 is concave, and its image side S12 is concave. The seventh lens L7 has negative optical power. Its object-side surface S13 is convex near the optical axis, and its image-side surface S14 is concave near the optical axis. The object-side surface S15 and the image-side surface S16 of filter G1 are both planar. The imaging plane S17 is a plane.

[0088] The third lens L3 is a glass spherical lens; the first lens L1, the second lens L2, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are all plastic aspherical lenses.

[0089] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0090] Table 1-1 The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0091] Table 1-2 In this embodiment, the F-Tan (Theta) distortion curve, transverse chromatic aberration curve, relative illumination curve, and MTF curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown.

[0092] Figure 2 The figure shows the F-Tan (Theta) distortion curve of the optical lens 100 in Embodiment 1, which represents the F-Tan (Theta) distortion of light at different image heights on the imaging plane. The horizontal axis represents the 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 -4% to 1%, indicating that the optical lens 100 can correct distortion well.

[0093] Figure 3 The diagram shows the transverse chromatic aberration curve of the optical lens 100 in Embodiment 1. It represents the chromatic aberration of each wavelength relative to the center wavelength (0.587 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the figure, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -0.5 μm to 2 μm, indicating that the optical lens 100 can effectively correct chromatic aberration.

[0094] Figure 4 The relative illumination curve of the optical lens 100 in Embodiment 1 is shown, which represents the relative illumination value at different image heights on the imaging plane. The horizontal axis represents the half-image height (unit: mm), and the vertical axis represents the relative illumination. As can be seen from the figure, the relative illumination value of the optical lens is still greater than 0.4 at the maximum half-image height, indicating that the optical lens 100 has good relative illumination.

[0095] Figure 5 The diagram shows the MTF (Modulation Transfer Function) curve of the optical lens 100 in Embodiment 1, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the OTF coefficient. As can be seen from the figure, the OTF coefficient of this embodiment is above 0.45 throughout the entire field of view. Within the range of 0–160 lp / mm, the curve decreases smoothly and uniformly 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.

[0096] Example 2 Please see Figure 6The figure shown is 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 optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0097] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0098] Table 2-1 The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0099] Table 2-2 In this embodiment, the F-Tan (Theta) distortion curve, transverse chromatic aberration curve, relative illumination curve, and MTF curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0100] from Figure 7 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -4% to 2%, indicating that the optical lens 200 can correct distortion well.

[0101] from Figure 8 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -0.5μm to 2μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0102] from Figure 9 As can be seen, the relative illumination value of the optical lens at the maximum half-image height is still greater than 0.4, indicating that the optical lens 200 has good relative illumination.

[0103] from Figure 10 As can be seen, the OTF coefficient of this embodiment is above 0.48 throughout the entire field of view. In the range of 0 to 160 lp / mm, the 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.

[0104] Example 3 Please see Figure 11 The figure shown is 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 optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0105] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0106] Table 3-1 The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0107] Table 3-2 In this embodiment, the F-Tan (Theta) distortion curve, transverse chromatic aberration curve, relative illumination curve, and MTF curve of the optical lens 300 are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0108] from Figure 12 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -4% to 2%, indicating that the optical lens 300 can correct distortion well.

[0109] from Figure 13 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -0.5μm to 2μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0110] from Figure 14 As can be seen, the relative illumination value of the optical lens at the maximum half-image height is still greater than 0.4, indicating that the optical lens 300 has very good relative illumination.

[0111] from Figure 15 As can be seen, the OTF coefficient of this embodiment is above 0.48 throughout the entire field of view. In the range of 0 to 160 lp / mm, the 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.

[0112] Example 4 Please see Figure 16 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 object-side surface S1 of the first lens L1 is convex; the object-side surface S9 of the fifth lens L5 is convex; the object-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.

[0113] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0114] Table 4-1 The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0115] Table 4-2 In this embodiment, the F-Tan (Theta) distortion curve, transverse chromatic aberration curve, relative illumination curve, and MTF curve of the optical lens 700 are respectively as follows: Figure 17 , Figure 18 , Figure 19 , Figure 20 As shown.

[0116] from Figure 17 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -4% to 2%, indicating that the optical lens 400 can correct distortion well.

[0117] from Figure 18 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -0.5μm to 2μm, indicating that the optical lens 400 can correct chromatic aberration well.

[0118] from Figure 19 As can be seen, the relative illumination value of the optical lens at the maximum half-image height is still greater than 0.4, indicating that the optical lens 400 has very good relative illumination.

[0119] from Figure 20 As can be seen, the OTF coefficient of this embodiment is above 0.4 throughout the entire field of view. In the range of 0 to 160 lp / mm, the 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.

[0120] Example 5 Please see Figure 21 The figure shows a schematic diagram 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 S1 of the first lens L1 is a convex surface; the object side surface S9 of the fifth lens L5 is a convex surface; and 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 500 in Example 5 are shown in Table 5-1.

[0122] Table 5-1 The surface profile parameters of the aspherical lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0123] Table 5-2 In this embodiment, the F-Tan (Theta) distortion curve, transverse chromatic aberration curve, relative illumination curve, and MTF curve of the optical lens 500 are respectively as follows: Figure 22 , Figure 23 , Figure 24 , Figure 25 As shown.

[0124] from Figure 22 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -4% to 2%, indicating that the optical lens 500 can correct distortion well.

[0125] from Figure 23 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within -0.5μm to 2μm, indicating that the optical lens 500 can correct chromatic aberration well.

[0126] from Figure 24 As can be seen, the relative illumination value of the optical lens is still greater than 0.4 at the maximum half-image height, indicating that the optical lens 500 has very good relative illumination.

[0127] from Figure 25 As can be seen, the OTF coefficient of this embodiment is above 0.45 throughout the entire field of view. Within the range of 0 to 160 lp / mm, the curve decreases smoothly and evenly from the center to the edge of the field of view, demonstrating good imaging quality and good detail resolution in both low and high frequency conditions.

[0128] Please refer to Table 6 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, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0129] Table 6 In summary, the optical lens provided by this invention employs a seven-element glass-plastic hybrid structure. Through specific surface shape settings and reasonable power distribution, the optical lens structure is relatively compact, effectively shortening the overall length of the optical lens and facilitating miniaturization. It features a large aperture, enabling high-definition imaging even in low-light environments. Simultaneously, it has a large field of view, providing a wide viewing area. Furthermore, it can reasonably correct overall aberrations of the optical lens, exhibiting low distortion and high resolution, thus improving the imaging quality of the optical lens.

[0130] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," and "some examples" 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.

[0131] 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, Along the optical axis from the object side to the imaging plane, the following are included in sequence: The first lens with negative optical power has a concave image-side surface. A second lens with positive optical power has a convex object-side surface and a concave image-side surface; A third lens with positive optical power has a convex object-side surface and a convex image-side surface. The fourth lens with positive optical power has a convex object-side surface and a convex image-side surface. The fifth lens with positive optical power has a convex image-side surface; The sixth lens has negative optical power, with both its object-side and image-side surfaces being concave. The seventh lens, which has negative optical power, has an image-side surface that is concave near the optical axis. Wherein, 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: 45°<(f×FOV) / IH<46°.

2. The optical lens according to claim 1, characterized in that, The total optical length (TTL) of the optical lens and the effective focal length (f) of the optical lens satisfy: 3.8 <TTL / f<3.9。 3. The optical lens according to claim 1, characterized in that, The back focal length (BFL) of the optical lens and the total optical length (TTL) of the optical lens satisfy: 0.08 <BFL / TTL<0.12。 4. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.4 <f1 / f<-2。 5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.2 <f3 / f<1.4。 6. The optical lens according to claim 1, characterized in that, The object-side radius of curvature R13 and the image-side radius of curvature R14 of the seventh lens satisfy the following condition: 0.9 < (R13 + R14) / (R13 - R14) < 5.

2.

7. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the focal length f7 of the seventh lens satisfy: 0.4 <f1 / f7<0.8。 8. The optical lens according to claim 1, characterized in that, The combined focal length f13 of the first lens, the second lens, and the third lens satisfies the following condition with respect to the effective focal length f of the optical lens: 1.3 <f13 / f<1.7。 9. The optical lens according to claim 1, characterized in that, The object-side light-transmitting half-aperture height SAG71 of the seventh lens, the image-side light-transmitting half-aperture height SAG72 of the seventh lens, and the center thickness CT7 of the seventh lens satisfy the following condition: -0.1 < (SAG72 - SAG71) / CT7 < 0.

1.

10. The optical lens according to claim 1, characterized in that, The true image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4.5 <IH / EPD<4.6。

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