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 positive 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 convex surface; the third lens has negative focal power, the object side surface of the third lens near the optical axis is a convex surface, and the image side surface of the third lens is a concave surface; the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a concave surface; wherein the focal length f1 of the first lens and the focal length f2 of the second lens meet the following conditions:-4.4 lt; f1 / f2lt; and-2.6. The optical lens provided by the invention can be simultaneously suitable for two wavebands of visible light and infrared light, and can improve the imaging quality of the optical lens, so that the lens has one or more advantages of small head, large aperture, large target surface and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of imaging lenses, in particular to an optical lens. BACKGROUND

[0002] With the vigorous development of science and technology in recent years, the market has higher and higher requirements for optical lenses, and major manufacturers have put forward more new demands for the scenes that the lenses can adapt. Among them, lenses that can be applied to both visible light and infrared wave bands have also emerged as the times require. Compared with conventional lenses, such lenses can be applied to a wider range and have stronger adaptability. SUMMARY

[0003] In view of the above problems, the purpose of the present application is to provide an optical lens with the advantages of infrared confocal and excellent imaging quality.

[0004] The technical scheme adopted by the present application is: An optical lens has five lenses with optical power, which include, in order along the optical axis from the object side to the imaging surface: a first lens with negative optical power, whose object side surface is a convex surface and whose image side surface is a concave surface; a second lens with positive optical power, whose object side surface is a convex surface; a third lens with negative optical power, whose object side surface is a convex surface near the optical axis and whose image side surface is a concave surface; a fourth lens with positive optical power, whose image side surface is a convex surface; a fifth lens with negative optical power, whose object side surface is a convex surface and whose image side surface is a concave surface; wherein the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -4.4 < f1 / f2 < -2.6.

[0005] Further preferably, the center thickness CT4 of the fourth lens and the center thickness CT5 of the fifth lens satisfy: 2.6 < CT4 / CT5 < 5.5.

[0006] Further preferably, the center thickness CT4 of the fourth lens and the edge thickness ET4 of the fourth lens satisfy: 2.2 < CT4 / ET4 < 2.8.

[0007] Further preferably, the image side surface half-entrance aperture sagittal height SAG42 of the fourth lens, the object side surface half-entrance aperture sagittal height SAG41 of the fourth lens, and the center thickness CT4 of the fourth lens satisfy: -0.7 < (SAG42-SAG41) / CT4 < -0.5.

[0008] It is further preferred that an image-side half-aperture radius sag of the fifth lens SAG52, an object-side half-aperture radius sag of the fifth lens SAG51 and a central thickness CT5 of the fifth lens satisfy: 0.8 < (SAG52-SAG51) / CT5 < 1.25.

[0009] It is further preferred that an object-side curvature radius R1 of the first lens and an image-side curvature radius R2 of the first lens satisfy: 1.1 < R1 / R2 < 1.7.

[0010] It is further preferred that a maximum field angle of the optical lens corresponds to a real image height IH, and an entrance pupil diameter EPD of the optical lens satisfy: 3.4 < IH / EPD < 4.2.

[0011] It is further preferred that an object-side half-aperture radius DM11 of the first lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.15 < DM11 / IH < 0.25.

[0012] It is further preferred that the object-side curvature radius R1 of the first lens, the image-side curvature radius R2 of the first lens and a central thickness CT1 of the first lens satisfy: 0.9 < R1 / (R2+CT1) < 1.6.

[0013] It is further preferred that a combined focal length f12 of the first lens and the second lens and a combined focal length f35 of the third lens, the fourth lens and the fifth lens satisfy: -3.5 < f12 / f35 < -2.3.

[0014] Compared with the prior art, the optical lens provided by the application can be applied to both visible light and infrared light by specific surface shape setting and reasonable focal power distribution, can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and make the lens have one or more advantages such as small head, large aperture, large target surface, etc. BRIEF DESCRIPTION OF DRAWINGS

[0015] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which: Figure 1 FIG. 1 is a structure schematic diagram of an optical lens according to an embodiment of the present application.

[0016] Figure 2 FIG. 2 is a field curvature curve diagram of the optical lens according to the embodiment of the present application.

[0017] Figure 3 FIG. 3 is a distortion curve diagram of the optical lens according to the embodiment of the present application.

[0018] Figure 4 Axial aberration curve of the optical lens in Embodiment 1 of the present application.

[0019] Figure 5 Axial aberration curve of the optical lens in Embodiment 1 of the present application.

[0020] Figure 6 Structure diagram of the optical lens in Embodiment 2 of the present application.

[0021] Figure 7 Axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0022] Figure 8 Axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0023] Figure 9 Axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0024] Figure 10 Axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0025] Figure 11 Structure diagram of the optical lens in Embodiment 3 of the present application.

[0026] Figure 12 Axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0027] Figure 13 Axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0028] Figure 14 Axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0029] Figure 15 Axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0030] Figure 16 Structure diagram of the optical lens in Embodiment 4 of the present application.

[0031] Figure 17 Axial aberration curve of the optical lens in Embodiment 4 of the present application.

[0032] Figure 18 Axial aberration curve of the optical lens in Embodiment 4 of the present application.

[0033] Figure 19 Axial aberration curve of the optical lens in Embodiment 4 of the present application.

[0034] Figure 20 Axial aberration curve of the optical lens in Embodiment 4 of the present application.

[0035] The following detailed description will further describe the present application with reference to the above figures. DETAILED DESCRIPTION

[0036] For a better understanding of the present application, various aspects of the present application will be described in greater detail below with reference to the figures. It should be appreciated that these details are just for embodiments of the present application and are not intended to limit the scope of the present application in any manner. Throughout the specification, like drawing reference numerals will be understood to refer to like parts throughout the specification and the figures. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] It should be noted that the expressions first, second, third, etc. in the present specification are merely used to distinguish one feature from another feature, and do not indicate any limitation on the features. Thus, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0038] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0039] In the present specification, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.

[0040] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, signify the presence of the stated features, elements, and / or components but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. Furthermore, when describing the embodiments of the present application, the use of "may" indicates that one or more embodiments of the present application. Also, the expression "exemplary" is intended to mean an example or an illustration.

[0041] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an overly literal or overly formal sense unless expressly so defined herein.

[0042] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0043] The optical lens provided by the embodiment of the present application has five lenses with optical power, which are sequentially arranged along the optical axis from the object side to the imaging surface as the first lens, the second lens, the third lens, the fourth lens and the fifth lens. The optical lens provided by the present application is an infrared lens, which is a lens specially used for capturing infrared light.

[0044] In some embodiments, the first lens can have negative optical power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface. The second lens can have positive optical power, the object side surface of which is a convex surface, and the image side surface of which can be a concave surface or a convex surface. The third lens can have negative optical power, the object side surface of which is a convex surface at the near optical axis, and the image side surface of which is a concave surface. The fourth lens can have positive optical power, the object side surface of which can be a concave surface or a convex surface, and the image side surface of which is a convex surface. The fifth lens can have negative optical power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface.

[0045] In some embodiments, the optical lens can further include a diaphragm, which can be located between the first lens and the second lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging. When the diaphragm is located between the first lens and the second lens, the correction of the diaphragm aberration is facilitated.

[0046] In some embodiments, the optical lens can further include a filter, which can be arranged between the fifth lens and the imaging surface. The filter is used to filter out interference light to prevent the interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0047] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -4.4 < f1 / f2 < -2.6. Satisfying the above condition can make the first lens and the second lens form chromatic aberration compensation, and help to compress the system length and balance the field curvature.

[0048] In some embodiments, the central thickness CT4 of the fourth lens and the central thickness CT5 of the fifth lens satisfy: 2.6 < CT4 / CT5 < 5.5. By reasonably setting the thickness relationship of the fourth and fifth lenses, the central thickness thereof satisfies the assembly stability requirement, while the assembly deformation and ghost reflection energy of the lens are reduced, and the imaging quality is improved.

[0049] In some embodiments, the central thickness CT4 of the fourth lens and the edge thickness ET4 of the fourth lens satisfy: 2.2 < CT4 / ET4 < 2.8. By controlling the ratio relationship between the thickness of the fourth lens on the optical axis and the edge thickness, the high-order aberration generated by the optical lens can be effectively balanced, and the field curvature adjustment of the fourth lens is facilitated, thereby improving the imaging quality of the optical lens.

[0050] In some embodiments, the central thickness CT4 of the fourth lens, the sagittal height of the light half aperture on the image side SAG42 of the fourth lens, and the sagittal height of the light half aperture on the object side SAG41 of the fourth lens satisfy: -0.7 < (SAG42-SAG41) / CT4 < -0.5. By controlling the relationship between the height difference of the sagittal height of the image side and the object side of the fourth lens and the central thickness of the fourth lens, the shape of the fourth lens can be constrained, which is conducive to the design and processing of the structure of the fourth lens, the correction of the aberration of each field of view, and the improvement of the imaging quality of the optical lens.

[0051] In some embodiments, the central thickness CT5 of the fifth lens, the sagittal height of the light half aperture on the image side SAG52 of the fifth lens, and the sagittal height of the light half aperture on the object side SAG51 of the fifth lens satisfy: 0.8 < (SAG52-SAG51) / CT5 < 1.25. By controlling the relationship between the height difference of the sagittal height of the image side and the object side of the fifth lens and the central thickness of the fifth lens, the coma of the off-axis field of view is corrected, and the imaging quality of the optical lens in the off-axis field of view is improved.

[0052] In some embodiments, the curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: 1.1 < R1 / R2 < 1.7. The face type of the first lens can be reasonably set to enhance the collection ability of the first lens to light, thereby realizing a larger field of view.

[0053] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.4 < IH / EPD < 4.2. By satisfying the above range, the optical lens can satisfy sufficient image plane brightness in the edge field of view while satisfying a large image plane, so as to prevent the occurrence of dark corner phenomenon, thereby improving the imaging quality.

[0054] In some embodiments, the clear aperture radius DM11 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: 0.15 < DM11 / IH < 0.25. Meeting the above range can ensure the balance between the front aperture diameter and the image plane size of the optical lens.

[0055] In some embodiments, the radius of curvature R1 of the object side of the first lens, the radius of curvature R2 of the image side of the first lens, and the central thickness CT1 of the first lens satisfy: 0.9 < R1 / (R2 + CT1) < 1.6. Meeting the above range can reduce the difficulty of correcting the marginal field distortion and control the distortion within a reasonable range.

[0056] In some embodiments, the combined focal length f12 of the first lens and the second lens and the combined focal length f35 of the third lens, the fourth lens, and the fifth lens satisfy: -3.5 < f12 / f35 < -2.3. Meeting the above range can reasonably allocate the ratio of the combined focal length of the first and second lenses to the combined focal length of the third, fourth, and fifth lenses, increase the relative illumination of the lens, and improve the imaging quality of the lens.

[0057] In some embodiments, the back focal length BFL of the optical lens and the total optical length TTL of the optical lens satisfy: 0.2 < BFL / TTL < 0.33. Reasonably configuring the ratio of the back focal length of the optical lens to the total optical length of the optical lens is beneficial to achieving a short back focal length of the optical lens. Under the condition of ensuring sufficient space for the installation and focusing of optical elements, it is beneficial to miniaturize the optical lens.

[0058] 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 / f < 2.3. Meeting the above conditions can effectively limit the length of the lens and is beneficial to miniaturizing the optical lens.

[0059] 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: 40° < (f × FOV) / IH < 50°. Meeting the above conditional formula is beneficial to achieving the balance between a large field angle 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.

[0060] 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: 1.7 < IH / f < 2. Meeting the above conditions can achieve a larger field angle and imaging range, and can realize 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.

[0061] 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: 0.9 < TTL / IH < 1.3. This can better achieve the miniaturization of the lens. Meanwhile, 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.

[0062] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -6 < f1 / f < -3. The first lens has an appropriate negative focal length, which is beneficial to expanding the field angle of view of the optical lens.

[0063] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 0.9 < f2 / f < 1.7. Meeting the above conditions, the second lens significantly converges light rays to shorten the total length of the system and compensates for the aberrations generated by the front group.

[0064] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -1.9 < f3 / f < -1.2. Meeting the above conditions, the third lens can finely adjust the angle of the chief ray and reduce the lens distortion.

[0065] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.48 < f4 / f < 0.6. Meeting the above conditions, the fourth lens can converge the incident light rays at the front end, which is beneficial to correcting the aberrations and the distortion of the edge field of view brought by the front-end lens group, making the lens have less distortion and being able to provide a high-definition imaging effect.

[0066] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -1 < f5 / f < -0.7. Meeting the above conditions, the fifth lens cooperates with the fourth lens to correct the field curvature, ensure that the edge and the center are clear simultaneously, and at the same time balance various aberrations generated by the front group of lenses, improving the imaging quality of the optical lens.

[0067] In some embodiments, the maximum field angle of view FOV of the optical lens and the true image height IH corresponding to the maximum field angle of view of the optical lens satisfy: 9° / mm < FOV / IH < 13° / mm. Meeting the above conditions, on the premise of meeting the image height requirements, it can ensure that the optical lens has a large field angle characteristic, so that the optical lens has good optical performance and can well capture the details of the photographed object.

[0068] In some embodiments, the maximum field angle of view FOV of the optical lens and the f-number Fno of the optical lens satisfy: 36° < FOV / Fno < 45°. Meeting the above conditions, it is beneficial to increase the light input of the lens, enabling the lens to achieve high-definition imaging even in a dim environment.

[0069] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the aperture value Fno of the optical lens satisfy: 3.3 mm < IH / Fno < 4.3 mm. Meeting the above conditions is conducive to achieving a large field angle of the lens while realizing the large aperture characteristic of the lens.

[0070] 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: 4 < (R1 + R2) / (R1 - R2) < 10. Meeting the above range, by adjusting the radii of curvature of the object side surface and the image side surface of the first lens, better light control ability can be provided, reducing light interference from the side or non-optical axis direction, reducing reflection and scattering, and improving the clarity and contrast of imaging.

[0071] In some embodiments, the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: 1.8 < (R9 + R10) / (R9 - R10) < 3.3. Meeting the above range, reasonably defining the shapes of the object side surface and the image side surface of the fifth lens can control the fifth lens to have an appropriate surface shape, which helps to control the light trend in the edge field of view and improve the imaging quality of the edge field of view.

[0072] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: 0.45 < R3 / f < 2.2. Meeting the above relational expression, controlling the surface shape of the object side surface of the second lens comprehensively balances the spherical aberration, chromatic aberration and field curvature of the optical system.

[0073] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 3 < R5 / f < 35. Reasonably controlling the radius of curvature of the object side surface of the third lens is conducive to controlling the shape of the third lens, optimizing the aberration balance of the lens group, and improving the imaging quality.

[0074] In some embodiments, the radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.18 < R10 / f < 0.32. Meeting the above range, by reasonably setting the radius of curvature of the image side surface of the fifth lens, it is conducive to balancing the aberration generated by the front-end lens, and at the same time is conducive to collecting the light in the edge field of view, improving the imaging quality of the edge field of view and increasing the imaging area of the optical lens.

[0075] In some embodiments, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -1.2 < f2 / f3 < -0.6. Reasonably distributing the optical power of the second lens and the third lens is conducive to the correction of chromatic aberration and improves the resolution ability of the system.

[0076] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -3.3 < f3 / f4 < -2.1; the focal length f4 of the fourth lens and the focal length f5 of the fifth lens satisfy: -0.8 < f4 / f5 < -0.55. By controlling the third lens, the fourth lens, and the fifth lens to have opposite optical powers, the optical system can have a better ability to balance aberrations.

[0077] In some embodiments, the focal length f1 of the first lens and the focal length f5 of the fifth lens satisfy: 3.5 < f1 / f5 < 7. Meeting the above conditions, by reasonably setting the focal length relationship between the first and last lenses in the lens, while ensuring that as much light as possible enters the system, the area of light entering the imaging surface is increased, which is beneficial to achieving large image surface imaging of the lens, while increasing the light input and improving the relative illumination of the system.

[0078] In some embodiments, the central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 0.05 < CT3 / CT4 < 0.25. Reasonably configuring the ratio of the thickness of the third lens on the optical axis to the thickness of the fourth lens on the optical axis enables the third lens and the fourth lens to regulate each other and maintain the characteristics of miniaturization of the optical system.

[0079] In some embodiments, the central thickness CT1 of the first lens and the edge thickness ET1 of the first lens satisfy: 0.9 < CT1 / ET1 < 1.5. By controlling the ratio relationship between the thickness of the first lens on the optical axis and the edge thickness, it is beneficial to balance the aberrations generated by the lens itself.

[0080] In some embodiments, the clear aperture radius DM11 of the object side of the first lens and the clear aperture radius DM52 of the image side of the fifth lens satisfy: 0.35 < DM11 / DM52 < 0.6. 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 pixel count.

[0081] In some embodiments, the Abbe number Vd2 of the second lens and the Abbe number Vd3 of the third lens satisfy: 30 < Vd2 - Vd3 < 35. When the above relationship is satisfied, it is beneficial to select appropriate lens materials, thereby effectively correcting chromatic aberration, further improving the imaging clarity of the optical system, and enhancing the imaging quality of the optical system.

[0082] In some embodiments, the optical lens satisfies the conditional formula: 3mm < f < 5mm, 7.5mm < TTL < 10mm, 2 < Fno < 2.1, 80° < FOV < 90°, 7mm < IH < 8.5mm; 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, 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 conditions indicates that the optical lens provided by the embodiments of the present invention has at least the following advantages: having a short overall length to achieve miniaturization of the lens; having a short focal length feature, and the depth of field of a short focal length lens is relatively deep, so that both the front and back of the subject can be kept relatively clear; having a large field angle to provide a wider shooting field of view for application scenarios such as lenses and capture more image information; having a large imaging surface, which can be matched with a larger size chip to achieve high-definition imaging; having a large aperture, which can be applicable to both visible light and infrared light bands at the same time, and high-definition imaging can be achieved even in a complex light environment.

[0083] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. 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 optical lens provided by the present invention can adopt an all-plastic lens structure, which not only enables the lens to have excellent imaging performance, but also makes the structure of the lens relatively compact, and can better achieve the balance between miniaturization of the lens and high image quality.

[0084] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better achieving miniaturization of the lens. More specifically, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens of the present invention can all adopt aspherical lenses.

[0085] In each embodiment of the present invention, when the lens adopts an aspherical lens, the surface shape of the aspherical lens satisfies the following equation: ; where z is the sagitta distance from the vertex of the aspherical surface when the aspherical surface is at a position with a height of h along the optical axis direction, c is the paraxial curvature of the surface, k is the conic coefficient, and A 2i is the aspherical surface type coefficient of the 2i-th order.

[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 includes, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, an aperture ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a filter G1.

[0088] Among them, the first lens L1 has negative optical power, its object side S1 is convex, 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 near the optical axis. The third lens L3 has negative optical power, its object side S5 is convex near the optical axis, 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 negative 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 imaging plane S13 is a plane.

[0089] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are all plastic aspherical lenses.

[0090] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0091] 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.

[0092] Table 1-2 In this embodiment, the field curvature curve, distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 ,Figure 3 , Figure 4 , Figure 5 As shown.

[0093] Figure 2 The field curvature curve of Embodiment 1 is shown, which represents the field curvature of light rays in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.05 mm, indicating that the optical lens 100 can effectively correct the field curvature.

[0094] Figure 3 The distortion curve of Embodiment 1 is shown, which represents the distortion at different image heights on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the field of view (unit: °). As can be seen from the figure, the distortion of the optical lens 100 is controlled within 0~2%, indicating that the distortion of the optical lens 100 is well corrected.

[0095] Figure 4 The diagram shows the axial aberration curves for Example 1, which represent the aberrations of each wavelength along 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 diagram, the axial aberration offset is controlled within ±0.02 mm, indicating that the optical lens 100 can effectively correct axial aberrations.

[0096] Figure 5 The diagram shows the transverse chromatic aberration curves for Example 1, representing the transverse chromatic aberration of each wavelength relative to the center wavelength (0.555 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 -1 μm to 2 μm, indicating that the optical lens 100 can effectively correct chromatic aberration.

[0097] Example 2 Please see Figure 6 The 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.

[0098] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0099] 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.

[0100] Table 2-2 In this embodiment, the field curvature curve, distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0101] from Figure 7 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.05mm to 0.1mm, indicating that the optical lens 200 can effectively correct the field curvature.

[0102] from Figure 8 As can be seen, the distortion of optical lens 200 is controlled within 0~2%, indicating that the distortion of optical lens 200 has been well corrected.

[0103] from Figure 9 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens 200 can effectively correct axial aberration.

[0104] from Figure 10 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 3μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0105] Example 3 Please see Figure 11 The figure shows a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side S4 of the second lens L2 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0106] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0107] 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.

[0108] Table 3-2 In this embodiment, the field curvature curve, distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 300 are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0109] from Figure 12 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.2mm to 0.05mm, indicating that the optical lens 300 can effectively correct the field curvature.

[0110] from Figure 13 As can be seen, the distortion of optical lens 300 is controlled within 0~2%, indicating that the distortion of optical lens 300 has been well corrected.

[0111] from Figure 14 As can be seen, the axial aberration offset is controlled within ±0.02mm, indicating that the optical lens 300 can effectively correct axial aberration.

[0112] from Figure 15 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 3μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0113] 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 image side S4 of the second lens L2 is a convex surface; the object side S7 of the fourth lens L4 is a concave surface; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0114] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0115] 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.

[0116] Table 4-2 In this embodiment, the field curvature curve, distortion curve, axial aberration curve, and transverse chromatic aberration curve of the optical lens 400 are respectively as follows: Figure 17 , Figure 18 , Figure 19 , Figure 20 As shown.

[0117] from Figure 17 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.15mm to 0.1mm, indicating that the optical lens 400 can effectively correct the field curvature.

[0118] from Figure 18As can be seen, the distortion of optical lens 400 is controlled within 0~1%, indicating that the distortion of optical lens 400 has been well corrected.

[0119] from Figure 19 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.05mm, indicating that the optical lens 400 can correct axial aberration well.

[0120] from Figure 20 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 3μm, indicating that the optical lens 400 can correct chromatic aberration well.

[0121] 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, 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.

[0122] Table 5-1 Table 5-2 In summary, the optical lens provided by the present invention, through specific surface shape settings and reasonable optical power allocation, can be applied to both visible and infrared light bands simultaneously, thereby improving the imaging quality of the optical lens, reducing aberrations, and enhancing the imaging quality of the optical lens, giving the lens one or more advantages such as a small head, large aperture, and large target surface.

[0123] 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.

[0124] 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 having a number of lenses with optical power of five pieces, characterized in that, In order from the object side to the imaging plane along the optical axis, comprising: a first lens with negative refractive power, the object side surface of which is convex, and the image side surface of which is concave; a second lens with positive refractive power, the object side surface of which is convex; a third lens with negative refractive power, the object side surface of which is convex at the near optical axis, and the image side surface of which is concave; a fourth lens with positive refractive power, the image side surface of which is convex; a fifth lens with negative refractive power, the object side surface of which is convex, and the image side surface of which is concave; wherein the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -4.4 < f1 / f2 < -2.

6.

2. The optical lens of claim 1, wherein, The central thickness CT4 of the fourth lens and the central thickness CT5 of the fifth lens satisfy: 2.6 < CT4 / CT5 < 5.

5.

3. The optical lens of claim 1, wherein, The central thickness CT4 of the fourth lens and the edge thickness ET4 of the fourth lens satisfy: 2.2 < CT4 / ET4 < 2.

8.

4. The optical lens of claim 1, wherein, The image side surface half-radii sagittal height SAG42 of the fourth lens, the object side surface half-radii sagittal height SAG41 of the fourth lens, and the central thickness CT4 of the fourth lens satisfy: -0.7 < (SAG42-SAG41) / CT4 < -0.

5.

5. The optical lens of claim 1, wherein, The image side surface half-radii sagittal height SAG52 of the fifth lens, the object side surface half-radii sagittal height SAG51 of the fifth lens, and the central thickness CT5 of the fifth lens satisfy: 0.8 < (SAG52-SAG51) / CT5 < 1.

25.

6. The optical lens of claim 1, wherein, The object side surface curvature radius R1 of the first lens and the image side surface curvature radius R2 of the first lens satisfy: 1.1 < R1 / R2 < 1.

7.

7. The optical lens of claim 1, wherein, The real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.4 < IH / EPD < 4.

2.

8. The optical lens of claim 1, wherein, The object side surface half-radii DM11 of the first lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.15 < DM11 / IH < 0.

25.

9. The optical lens of claim 1, wherein, The object side surface curvature radius R1 of the first lens, the image side surface curvature radius R2 of the first lens, and the central thickness CT1 of the first lens satisfy: 0.9 < R1 / (R2+CT1) < 1.

6.

10. The optical lens of claim 1, wherein, The combined focal length f12 of the first lens and the second lens and the combined focal length f35 of the third lens, the fourth lens, and the fifth lens satisfy: -3.5 < f12 / f35 < -2.3.

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