Optical lens

Abstract

The invention provides an optical lens, which comprises five lenses with focal power, 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 negative focal power, a fifth lens with negative focal power and a sixth 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 concave surface, and the image side surface of the second lens is a convex surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; the fourth lens has positive focal power, and the object side surface of the fourth lens is a convex surface; the fifth lens has positive focal power; wherein the combined focal length f345 of the third lens, the fourth lens and the fifth lens and the effective focal length f of the optical lens meet the following conditions: 1.2 lt; f345 / flt; and 1.7. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal power distribution, the lens has one or more advantages of large image surface, long focus, large aperture, high imaging quality and the like.

Description

Technical Field

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

[0002] With the continuous improvement of people's requirements for driving experience, on-vehicle application optical lenses are increasingly used in intelligent driving, and the status of on-vehicle optical lenses in the automotive-related industry is constantly rising.

[0003] Advanced Driver Assistance Systems (ADAS) play an important role in intelligent driving. It collects environmental information through various lenses and sensors to ensure the driving safety of the driver. In addition to requiring the optical lens to have a thin, light, short, and small shape and high pixel and high resolution characteristics, the existing ADAS system lenses also require the optical lens to be able to clearly image under low illuminance conditions. Therefore, an optical lens with good imaging effect needs to be developed. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide an optical lens, which has the advantage of excellent imaging quality.

[0005] The technical solution adopted by the present invention is as follows: An optical lens, the number of lenses with optical power is five, and it sequentially includes from the object side to the imaging surface along the optical axis: A first lens with negative optical power, its object side surface is concave, and its image side surface is concave; A second lens with positive optical power, its object side surface is concave, and its image side surface is convex; A third lens with negative optical power, its object side surface is convex, and its image side surface is concave; A fourth lens with positive optical power, its object side surface is convex; A fifth lens with positive optical power; Wherein, the combined focal length f345 of the third lens, the fourth lens and the fifth lens and the effective focal length f of the optical lens satisfy: 1.2 < f345 / f < 1.7; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -14 < R3 / f < -2.6.

[0006] Further preferably, the clear aperture radius d1 of the object side surface of the first lens and the clear aperture radius d10 of the image side surface of the fifth lens satisfy: 1.1 < d1 / d10 < 1.45; the clear aperture radius d1 of the object side surface of the first lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.55 < d1 / IH < 0.7.

[0007] Further preferably, the image-side half-aperture sagitta SAG10 of the fifth lens and the image-side half-aperture d10 of the fifth lens satisfy: -0.45 <SAG10 / d10<0.25。

[0008] Further preferably, the object-side light-transmitting half-aperture height SAG5 of the third lens, the image-side light-transmitting half-aperture height SAG6 of the third lens, and the center thickness CT3 of the third lens satisfy: 0.8 < (SAG6 - SAG5) / CT3 < 1.

[0009] Further preferably, the total optical length (TTL) of the optical lens, the true image height (IH) corresponding to the maximum field of view (FOV) of the optical lens, and the maximum field of view (FOV) of the optical lens satisfy: 0.01 / ° <TTL / IH / FOV<0.1 / °。

[0010] Further preferably, the half-aperture d1 of the object-side surface of the first lens, the true image height IH corresponding to the maximum field of view of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 0.65 <d1 / IH / tan(FOV / 2)<0.92。

[0011] Further preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.8 <f2 / f<4。

[0012] Further preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -1.25 <f3 / f<-0.95。

[0013] More preferably, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -1.45 <f3 / f4<-0.55。

[0014] Further preferably, the center thickness CT3 of the third lens and the center thickness CT4 of the fourth lens satisfy: 0.2 <CT3 / CT4<0.85。

[0015] The optical lens provided by this invention uses five lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as large image area, long focal length, large aperture, 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 a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 3 This is the F-Theta distortion curve of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 4 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 5 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0021] Figure 6 This is a relative illumination curve of the optical lens in Embodiment 1 of the present invention.

[0022] Figure 7 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0023] Figure 8 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0024] Figure 9 This is the F-Theta distortion curve of the optical lens in Embodiment 2 of the present invention.

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

[0026] Figure 11 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0027] Figure 12 This is a relative illumination curve of the optical lens in Embodiment 2 of the present invention.

[0028] Figure 13 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 14 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0030] Figure 15 This is the F-Theta distortion curve of the optical lens in Embodiment 3 of the present invention.

[0031] Figure 16 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0032] Figure 17 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0033] Figure 18 This is a relative illumination curve of the optical lens in Embodiment 3 of the present invention.

[0034] Figure 19 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0035] Figure 20 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0036] Figure 21 This is the F-Theta distortion curve of the optical lens in Embodiment 4 of the present invention.

[0037] Figure 22 This is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0038] Figure 23 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0039] Figure 24 This is a relative illumination curve of the optical lens in Embodiment 4 of the present invention.

[0040] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] The optical lens provided in this embodiment of the invention has five lenses with optical power, which are arranged sequentially from the object side to the imaging plane along the optical axis as a first lens, a second lens, a third lens, a fourth lens, and a fifth lens.

[0049] In some embodiments, the first lens may have negative optical power, with both its object-side and image-side surfaces being concave. The second lens may have positive optical power, with both its object-side and image-side surfaces being concave. The third lens may have negative optical power, with both its object-side and image-side surfaces being convex. The fourth lens may have positive optical power, with both its object-side and image-side surfaces being either concave or convex. The fifth lens may have positive optical power, with both its object-side and image-side surfaces being either concave or convex.

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

[0051] In some embodiments, the optical lens may further include a filter and a protective glass, which may be sequentially arranged along the optical axis between the fifth lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging. The protective glass plays a role in protecting the optical lens and preventing the photosensitive chip from being damaged and affecting the imaging effect of the lens.

[0052] In some embodiments, the combined focal length f345 of the third lens, the fourth lens and the fifth lens and the effective focal length f of the optical lens satisfy: 1.2 < f345 / f < 1.7. Meeting the above requirements, by reasonably distributing the optical power of the third lens to the fifth lens, balancing the focal length of the optical lens, improving the correction ability of various aberrations at the rear end of the lens, and enhancing the imaging quality of the optical lens.

[0053] In some embodiments, the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -14 < R3 / f < -2.6. Reasonably controlling the relationship between the curvature radius of the object side surface of the second lens and the effective focal length of the optical lens is beneficial to controlling the shape of the second lens, optimizing the aberration balance of the lens group, and enhancing the imaging quality.

[0054] In some embodiments, the clear aperture semi-diameter d1 of the object side surface of the first lens and the clear aperture semi-diameter d10 of the image side surface of the fifth lens satisfy: 1.1 < d1 / d1 = 1.45. 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, better meeting the balance of miniaturization and high pixels.

[0055] In some embodiments, the clear aperture semi-diameter d1 of the object side surface of the first lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.55 < d1 / IH < 0.7. Meeting the above conditions can ensure that the lens has a large field angle while ensuring that the overall size of the lens is moderate.

[0056] In some embodiments, the sagittal height SAG10 of the image side surface of the fifth lens and the clear aperture semi-diameter d10 of the image side surface of the fifth lens satisfy: -0.45 < SAG10 / d10 < 0.25. Reasonably controlling the sagittal height and aperture of the image side surface of the fifth lens, controlling the light beam trend and performing final imaging, ensuring that the opening angle of the fifth lens is within a certain range, which is beneficial for the optical lens to achieve high resolution and enables the optical lens to have high imaging quality.

[0057] In some embodiments, the sagittal height SAG5 of the clear aperture semi-diameter on the object side of the third lens, the sagittal height SAG6 of the clear aperture semi-diameter on the image side of the third lens, and the central thickness CT3 of the third lens satisfy: 0.8 < (SAG6 - SAG5) / CT3 < 1. Meeting the above conditions, by controlling the relationship between the height difference of the sagittal heights of the image side and the object side of the third lens and the central thickness of the third lens, it is beneficial to correct the coma of the off-axis field and improve the imaging quality of the off-axis field of the optical lens.

[0058] In some embodiments, the total optical length TTL of the optical 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: 0.01 / ° < TTL / IH / FOV < 0.1 / °. Meeting the above range can achieve a balance among large image height, long focal length, and miniaturization, and improve the imaging quality of the optical lens.

[0059] In some embodiments, the clear aperture semi-diameter d1 on 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: 0.65 < d1 / IH / tan(FOV / 2) < 0.92. Meeting the above range can ensure the balance among the size of the optical lens, the field angle, and the image plane.

[0060] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.8 < f2 / f < 4. The second lens converges the incident light rays at the front end, which is beneficial to correcting the aberrations brought by the front lens group and the distortion of the edge field, making the lens have less distortion and capable of providing a high-definition imaging effect.

[0061] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -1.25 < f3 / f < -0.95; the radius of curvature R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: 0.9 < R5 / f < 1.55; the radius of curvature R6 of the image side of the third lens and the effective focal length f of the optical lens satisfy: 0.3 < R6 / f < 0.5. Meeting the above conditions, the third lens uses a negative focal lens with a strong refractive power, which is beneficial to further increasing the imaging area of the optical lens, balancing various aberrations generated by the front group of lenses, and improving the imaging quality of the optical lens. At the same time, it can make the light path more stable; it can also correct coma and field curvature, improve the flatness of imaging, and enhance the imaging quality of the optical lens.

[0062] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -1.45 < f3 / f4 < -0.55. Meeting the above conditions, by reasonably setting the focal lengths of the third and fourth lenses, the convergence of light can be better achieved, the distance for light to enter the next lens can be shortened, which is beneficial to the miniaturization of the optical lens.

[0063] In some embodiments, the central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 0.2 < CT3 / CT4 < 0.85. Meeting the above relational expression, the two match each other, which helps to eliminate axial chromatic aberration.

[0064] In some embodiments, the combined focal length f12 of the first lens and the second lens and the combined focal length f345 of the third lens, the fourth lens and the fifth lens satisfy: -36 < f12 / f345 < 8.8. Meeting the above range can reasonably allocate the proportion of the optical power of the lens groups before and after the diaphragm, increase the relative illumination of the lens, and improve the imaging quality of the lens.

[0065] In some embodiments, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: -48 < f12 / f < 13. Meeting the above requirements, by reasonably allocating the optical power from the first lens to the second lens, the deflection angle of the light rays at the front end of the lens is reduced, and the generation of various off-axis aberrations is reduced.

[0066] 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: 0.1 < CT23 / TTL < 0.2. By controlling the distance between the lens groups before and after the diaphragm, it helps to improve the structural compactness of the optical lens.

[0067] In some embodiments, the sagittal height SAG3 of the clear aperture semi-diameter on the object side of the second lens, the sagittal height SAG4 of the clear aperture semi-diameter on the image side of the second lens, and the central thickness CT2 of the second lens satisfy: -0.25 < (SAG4 - SAG3) / CT2 < -0.05. Meeting the above conditions can limit the degree of central depression of the second lens and reduce the difficulty of off-axis aberration correction in the marginal field of view.

[0068] In some embodiments, the sagittal height SAG7 of the clear aperture semi-diameter on the object side of the fourth lens, the sagittal height SAG8 of the clear aperture semi-diameter on the image side of the fourth lens, and the central thickness CT4 of the fourth lens satisfy: -0.7 < (SAG8 - SAG7) / CT4 < -0.27. Meeting the above conditions can control the surface shape of the object side of the fourth lens, which is beneficial to the manufacturing and forming of the fourth lens, reducing the defective rate. In addition, it can also prevent the surface shape from being too curved and complex, making the system field curvature tend to be balanced.

[0069] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 3.6 < TTL / f < 4.6. It can effectively limit the length of the lens, which is beneficial to the miniaturization of the optical lens.

[0070] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of view of the optical lens satisfy: 3 < TTL / IH < 3.8. This 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 and can match a larger-sized imaging chip to achieve high-definition imaging.

[0071] In some embodiments, the true image height IH corresponding to the maximum field angle of view of the optical lens, the effective focal length f of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.65 < (IH / 2) / (f × tan(FOV / 2)) < 0.85. Meeting the above requirements indicates that the optical distortion of the optical lens is well controlled, improving the resolution of the optical lens.

[0072] In some embodiments, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 32° < FOV / Fno < 48°. Meeting the above conditions is beneficial to increasing the light input of the lens, enabling the lens to achieve high-definition imaging even in a dim environment.

[0073] In some embodiments, the true image height IH corresponding to the maximum field angle of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 2 < IH / EPD < 2.8. Meeting the above range enables the optical lens to satisfy a large image plane while also ensuring sufficient image plane brightness in the edge field of view, preventing the occurrence of vignetting and thus improving the imaging quality.

[0074] In some embodiments, the true image height IH corresponding to the maximum field angle of view of the optical lens and the effective focal length f of the optical lens satisfy: 1 < IH / f < 1.4. Meeting the above conditions can achieve a larger field angle of view and imaging range, and can achieve the characteristics of a large image plane while ensuring the depth of field of the optical lens, thereby improving the imaging quality of the optical system.

[0075] In some embodiments, the distance BL on the optical axis from the image side of the fifth lens to the imaging plane and the effective focal length f of the optical lens satisfy: 0.8 < BL / f < 1.75. Meeting the above range is beneficial to achieving a balance between obtaining good imaging quality and easy assembly, ensuring the imaging quality of the optical lens while avoiding interference between the lens and other components, and reducing the assembly process difficulty of the camera module.

[0076] In some embodiments, the true image height IH corresponding to the maximum field angle of view of the optical lens, the effective focal length f of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 60° < f × FOV / IH < 70°. Meeting the above conditional formula is beneficial to achieving the balance of the field angle of view and large target surface imaging of the optical lens by reasonably restricting the relationship between the focal length, field angle, and image height of the optical lens, and better meeting the use requirements of high image quality shooting of the optical lens.

[0077] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis satisfy: 0.32 < ∑CT / TTL < 0.65. Satisfying the above range can effectively compress the total length of the optical lens, and is conducive to the structural design and production process of the optical lens.

[0078] In some embodiments, the distance BL on the optical axis from the image side of the fifth lens to the imaging surface and the total optical length TTL of the optical lens satisfy: 0.18 < BL / TTL < 0.45. This is conducive to achieving a short back focal length of the optical lens, and is conducive to miniaturizing the optical lens while ensuring sufficient space for the installation and focusing of optical elements.

[0079] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the F-number Fno of the optical lens satisfy: 3 mm < IH / Fno < 4.4 mm. Satisfying the above conditions can maintain a large image surface for the optical lens while ensuring a large aperture for the optical lens, achieving an equilibrium between a large image surface and a large aperture.

[0080] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -2.7 < f1 / f < -1.4; 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: -4.7 < (R1 - R2) / (R1 + R2) < -1.2. The first lens has an appropriate negative focal length, which is conducive to expanding the field angle of the optical lens. At the same time, it is conducive to the divergence of light rays, obtaining a larger picture, effectively eliminating aberration, and improving the resolution ability of the optical lens.

[0081] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.8 < f4 / f < 1.8. Satisfying the above conditions, the fourth lens uses a positive focal lens with strong refractive power, which can further focus light rays, adjust the angle of chief rays, optimize the imaging quality, and correct residual aberrations (such as distortion, chromatic aberration, etc.), reducing the distortion of the wide-angle lens.

[0082] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.9 < f5 / f < 18. The fifth lens performs final imaging on the light beam converged by the fourth lens. Ensuring that the effective focal length of the fifth lens is within a certain range is conducive to achieving high imaging quality.

[0083] In some embodiments, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -3.5 < f2 / f3 < -1.8. By reasonably setting the ratio of the focal lengths of the second lens and the third lens, the system length can be shortened, the aberration and the distortion of the marginal field of view can be reduced, so that the lens has less distortion and can provide a high-definition imaging effect.

[0084] In some embodiments, the central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy: 3.6 < CT2 / CT3 < 6.7. The ratio of the thickness of the second lens on the optical axis to the thickness of the third lens on the optical axis is reasonably configured, and the second lens and the third lens can regulate each other to maintain the characteristic of miniaturization of the optical system.

[0085] The radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -2.2 < R1 / f < -1.3; 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: 3 < R2 / f < 11. By reasonably configuring the ratio of the radius of curvature of the object side surface of the first lens to the effective focal length of the optical lens, the first lens can collect as much light with a large field angle as possible and make the light enter the subsequent system smoothly, increasing the light transmission amount of the optical lens and effectively expanding the field of view range of the optical lens.

[0086] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: 0.3 < (R3 - R4) / (R3 + R4) < 0.85. By making the optical system satisfy the above relational expression, it is beneficial to reasonably configure the ratio of the radius of curvature of the object side surface of the second lens to the radius of curvature of the image side surface of the second lens, control the shape of the second lens, comprehensively balance the spherical aberration, chromatic aberration and field curvature of the optical system, and reduce the risk of generating ghost images, improve the resolution ability of the optical system. At the same time, it is also beneficial to reduce the processing difficulty of the second lens.

[0087] In some embodiments, the optical lens satisfies: 5.5mm < f < 6mm; 2.5mm < EPD < 3.5mm; 23mm < TTL < 26mm; 1.9 < Fno < 2.1; 12° < CRA < 16°; 5mm < BL < 10mm; 65° < FOV < 90°; 6mm < IH < 8mm. 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 overall optical length of the optical lens, Fno represents the aperture value of the optical lens, CRA represents the chief ray angle of incidence at the maximum image height of the optical lens, BL represents the distance from the image side of the fifth lens to the imaging surface on the optical axis, 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 target surface, a large aperture, and a long focal length characteristic.

[0088] 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. On the other hand, 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 third lens and the fourth lens of the present invention are made of plastic material; the first lens, the second lens, and the fifth lens are made of glass material.

[0089] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens can be 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 and the fourth lens of the present invention are aspherical lenses; the first lens, the second lens, and the fifth lens are spherical lenses.

[0090] In various embodiments of the present invention, when the lens is an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations: ; where z is the distance between the surface and the vertex of the surface in the optical axis direction, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the conic coefficient, and B, C, D, E, F, G, H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients respectively.

[0091] 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.

[0092] Example 1 Please see Figure 1 The figure shown is a schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, in sequence along the optical axis from the object side to the imaging surface: a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a filter G1, and a protective glass G2.

[0093] Among them, the first lens L1 has negative optical power, its object side S1 is concave, and its image side S2 is concave. The second lens L2 has positive optical power, its object side S3 is concave, and its image side S4 is convex. The third lens L3 has negative optical power, its object side S5 is convex, and its image side S6 is concave. 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 convex, and its image side S10 is concave. The object-side surface S11 and the image-side surface S12 of the filter G1 are both planar. The object side S13 and the image side S14 of the protective glass G2 are both flat. The imaging plane S15 is a plane.

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

[0095] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0096] 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.

[0097] Table 1-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown.

[0098] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light 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 -0.06 mm to 0.04 mm, indicating that the optical lens can effectively correct the field curvature.

[0099] Figure 3 The F-Theta distortion curve of Example 1 is shown, which represents the F-Theta distortion of light of different wavelengths 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-Theta distortion of the optical lens is controlled within -15% to 0, indicating that the optical lens can correct distortion well.

[0100] Figure 4 The axial aberration curve of Example 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial aberration offset is controlled within -0.01 mm to 0.02 mm, indicating that the optical lens can correct axial aberration well.

[0101] Figure 5 The diagram shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.558 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 diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -3 μm to 2 μm, indicating that the optical lens can effectively correct chromatic aberration.

[0102] Figure 6 The relative illumination curve of Example 1 is shown, which represents the relative illumination value at different field-of-view angles on the imaging plane. The horizontal axis represents the half field of view (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is greater than 80%, indicating that the optical lens has good relative illumination.

[0103] Example 2 Please see Figure 7 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 image-side surface S8 of the fourth lens L4 is concave, the image-side surface S10 of the fifth lens L5 is convex, and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0104] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0105] 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.

[0106] Table 2-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 200 are respectively as follows: Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 As shown.

[0107] from Figure 8 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.06mm to 0.04mm, indicating that the optical lens can effectively correct the field curvature.

[0108] from Figure 9 As can be seen, the F-Theta distortion of the optical lens is controlled within -10% to 0, indicating that the optical lens can correct distortion well.

[0109] from Figure 10 As can be seen, the axial aberration offset is controlled within -0.01mm to 0.02mm, indicating that the optical lens can effectively correct axial aberration.

[0110] from Figure 11 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±3μm, indicating that the optical lens can effectively correct chromatic aberration.

[0111] from Figure 12 As can be seen, the relative illumination value of the optical lens is greater than 90%, indicating that the optical lens has good relative illumination.

[0112] Example 3 Please see Figure 13The 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 image-side surface S8 of the fourth lens L4 is concave; the object-side surface S9 of the fifth lens L5 is concave; the image-side surface S10 of the fifth lens L5 is convex; 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 300 in Example 3 are shown in Table 3-1.

[0114] 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.

[0115] Table 3-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 300 are respectively as follows: Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 As shown.

[0116] from Figure 14 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.05mm to 0.15mm, indicating that the optical lens can effectively correct the field curvature.

[0117] from Figure 15 As can be seen, the F-Theta distortion of the optical lens is controlled within -15% to 0, indicating that the optical lens can correct distortion well.

[0118] from Figure 16 As can be seen, the axial aberration offset is controlled within ±0.03mm, indicating that the optical lens can effectively correct axial aberration.

[0119] from Figure 17 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±4μm, indicating that the optical lens can effectively correct chromatic aberration.

[0120] from Figure 18 As can be seen, the relative illumination value of the optical lens is greater than 80%, indicating that the optical lens has good relative illumination.

[0121] Example 4 Please see Figure 19The 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 S9 of the fifth lens L5 is concave; the image side S10 of the fifth lens L5 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0122] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0123] 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.

[0124] Table 4-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 400 are respectively as follows: Figure 20 , Figure 21 , Figure 22 , Figure 23 , Figure 24 As shown.

[0125] from Figure 20 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.1mm to -0.02mm, indicating that the optical lens can effectively correct the field curvature.

[0126] from Figure 21 As can be seen, the F-Theta distortion of the optical lens is controlled within -15% to 0, indicating that the optical lens can correct distortion well.

[0127] from Figure 22 As can be seen, the axial aberration offset is controlled within -0.05mm to 0.03mm, indicating that the optical lens can effectively correct axial aberration.

[0128] from Figure 23 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±3μm, indicating that the optical lens can effectively correct chromatic aberration.

[0129] from Figure 24 As can be seen, the relative illumination value of the optical lens is greater than 90%, indicating that the optical lens has good relative illumination.

[0130] Please refer to Tables 5-1 and 5-2 for the optical characteristics corresponding to 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, principal ray incident angle CRA at the maximum image height, distance BL from the image side of the fifth lens to the imaging plane on the optical axis, and the numerical values ​​corresponding to each conditional expression in each embodiment.

[0131] Table 5-1 Table 5-2 In summary, the optical lens provided by the present invention employs five lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as large image area, long focal length, large aperture, and high imaging quality.

[0132] 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.

[0133] 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 five lenses having optical power, characterized in that, It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side is concave and whose image side is concave; A second lens with a positive optical power, whose object side is concave and whose image side is convex; A third lens with a negative optical power, whose object side is convex and whose image side is concave; A fourth lens with a positive optical power, whose object side is convex; A fifth lens with a positive optical power; Wherein, the combined focal length f345 of the third lens, the fourth lens and the fifth lens and the effective focal length f of the optical lens satisfy: 1.2 < f345 / f < 1.7; The curvature radius R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: -14 < R3 / f < -2.

6.

2. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter d1 of the object side of the first lens and the clear aperture semi-diameter d10 of the image side of the fifth lens satisfy: 1.1 < d1 / d10 < 1.45; The clear aperture semi-diameter d1 of the object side of the first lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.55 < d1 / IH < 0.

7.

3. The optical lens according to claim 1, characterized in that, The sagittal height SAG10 of the clear aperture of the image side of the fifth lens and the clear aperture semi-diameter d10 of the image side of the fifth lens satisfy: -0.45 < SAG10 / d10 < 0.

25.

4. The optical lens according to claim 1, characterized in that, The sagittal height SAG5 of the clear aperture of the object side of the third lens, the sagittal height SAG6 of the clear aperture of the image side of the third lens and the central thickness CT3 of the third lens satisfy: 0.8 < (SAG6 - SAG5) / CT3 < 1.

5. The optical lens according to claim 1, characterized in that, The total optical length TTL of the optical 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: 0.01 / ° < TTL / IH / FOV < 0.1 / °.

6. 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: 0.65 < d1 / IH / tan(FOV / 2) < 0.

92.

7. The optical lens according to claim 1, characterized in that, The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.8 < f2 / f < 4.

8. The optical lens according to claim 1, characterized in that, The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -1.25 < f3 / f < -0.95; The curvature radius R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: 0.9 < R5 / f < 1.55; The curvature radius R6 of the image side of the third lens and the effective focal length f of the optical lens satisfy: 0.3 < R6 / f < 0.

5.

9. The optical lens according to claim 1, characterized in that, The focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -1.45 < f3 / f4 < -0.

55.

10. The optical lens according to claim 1, characterized in that, The central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 0.2 < CT3 / CT4 < 0.85.

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