Optical lens

Abstract

The present invention provides an optical lens, which sequentially includes, along the optical axis from the object side to the imaging surface: a first lens with a negative optical power, whose object side is convex and whose image side is concave; a second lens with a positive optical power, whose object side is convex; a third lens with a positive optical power, whose object side is convex near the optical axis and whose image side is convex; a fourth lens with a negative optical power, whose object side is concave and whose image side is convex; a fifth lens with a positive optical power, whose object side is convex near the optical axis and whose image side is concave; wherein, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 136° < FOV / Fno < 151°. The optical lens provided by the present invention can improve the imaging quality of the optical lens, reduce aberration, and improve the imaging quality of the optical lens through specific surface shape settings and reasonable optical power distribution, enabling the lens to have one or more advantages such as a large field of view, a large aperture, and a large target surface.

Description

Technical Field

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

[0002] Infrared lenses are lenses specifically designed to capture infrared light. They play an important role in infrared photography and infrared sensing. Their uses include: First, military intelligence personnel can use infrared lenses for night vision surveillance, detecting targets and monitoring enemy movements. Infrared technology plays a crucial role in nighttime operations, helping combatants conduct reconnaissance and search operations in darkness, improving combat efficiency and ensuring the smooth execution of military operations. Second, in security and surveillance, infrared lenses are also widely used in this field. Security and surveillance systems can use infrared lenses for night vision surveillance, capturing clear footage even at night or in low-light conditions. Infrared lenses help monitor personnel detect anomalies promptly, protecting lives and property. Third, in thermal imaging, infrared lenses can also be used for thermal imaging, which uses the infrared heat radiated by an object to display its temperature distribution. Thermal imaging technology has widespread applications in medicine, construction, agriculture, and other fields. In medicine, thermal imaging is used to diagnose diseases; in construction, it is used to monitor the temperature distribution of building structures; and in agriculture, it is used to monitor crop growth. How to make infrared lenses compatible with large aperture and large field of view is an urgent problem to be solved. Summary of the Invention

[0003] In view of the above problems, the object of the present invention is to provide an optical lens having advantages such as excellent imaging quality.

[0004] The technical solution adopted in the present invention is:

[0005] An optical lens, comprising five lenses, including the following elements in order from the object side to the imaging surface along the optical axis:

[0006] The first lens has a negative optical power, its object-side surface is convex and its image-side surface is concave;

[0007] a second lens having positive optical power and a convex object-side surface;

[0008] The third lens has positive refractive power, its object-side surface is convex near the optical axis, and its image-side surface is convex;

[0009] a fourth lens element having negative optical power, whose object-side surface is concave and whose image-side surface is convex;

[0010] The fifth lens element has positive refractive power, its object-side surface is convex near the optical axis, and its image-side surface is concave;

[0011] Among them, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 136° < FOV / Fno < 151°.

[0012] Further preferably, the effective focal length f of the optical lens and the overall optical length TTL of the optical lens satisfy: 3.7 < TTL / f < 4; the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 1.25 < TTL / IH < 1.4.

[0013] Further preferably, the effective focal length f of the optical lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the radian value θ of the maximum half-field angle of the optical lens satisfy: 0.99 < (IH / 2) / (f×θ) < 1.02; the overall optical length TTL of the optical lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 1.4 < 180°×TTL / IH / FOV < 1.55.

[0014] Further preferably, the true 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: 3.1 < IH / EPD < 3.5; the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 2.8 < IH / f < 3.

[0015] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.3 < f1 / f < -1.7; the effective focal length f of the optical lens and the curvature radius R1 of the object side surface of the first lens satisfy: 13 < R1 / f < 446; the effective focal length f of the optical lens and the curvature radius R2 of the image side surface of the first lens satisfy: 1.1 < R2 / f < 1.3.

[0016] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1 < f3 / f < 1.4; the effective focal length f of the optical lens and the curvature radius R5 of the object side surface of the third lens satisfy: 1.1 < R5 / f < 2.7; the effective focal length f of the optical lens and the curvature radius R6 of the image side surface of the third lens satisfy: -1.3 < R6 / f < -1.1.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -25.5 < f4 / f < -4.5; the effective focal length f of the optical lens and the object-side curvature radius R7 of the fourth lens satisfy: -0.9 < R7 / f < -0.4; the effective focal length f of the optical lens and the image-side curvature radius R8 of the fourth lens satisfy: -1.1 < R8 / f < -0.6.

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 4 < f5 / f < 8; the effective focal length f of the optical lens and the object-side curvature radius R9 of the fifth lens satisfy: 0.7 < R9 / f < 1.3; the effective focal length f of the optical lens and the image-side curvature radius R10 of the fifth lens satisfy: 0.8 < R10 / f < 1.4.

[0019] Further preferably, the focal length f1 of the first lens and the combined focal length f2345 of the second lens, the third lens, the fourth lens and the fifth lens satisfy: -2.1 < f1 / f2345 < -1.7; the object-side clear aperture radius d1 of the first lens and the image-side clear aperture radius d10 of the fifth lens satisfy: 0.95 < d1 / d10 < 1.

[0020] Further preferably, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -0.35 < f3 / f4 < 0; the central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 1 < CT3 / CT4 < 3.

[0021] Compared with the prior art, the optical lens provided by the present invention can improve the imaging quality of the optical lens, reduce aberration, and improve the imaging quality of the optical lens by setting a specific surface shape and reasonably distributing the optical power, so that the lens has one or more advantages such as a large field angle, a large aperture, and a large target surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0024] Figure 2 is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0025] Figure 3 is an F-Theta distortion curve diagram of the optical lens in Embodiment 1 of the present invention.

[0026] Figure 4 Graph showing vertical axis chromatic aberration of the optical lens in Example 1 of the present invention.

[0027] Figure 5 This is a relative illumination curve diagram of the optical lens in Example 1 of the present invention.

[0028] Figure 6 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0029] Figure 7 Graph showing the field curvature of the optical lens in Example 2 of the present invention.

[0030] Figure 8 Graph showing the F-Theta distortion of the optical lens in Example 2 of the present invention.

[0031] Figure 9 Graph showing vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0032] Figure 10 This is a relative illumination curve diagram of the optical lens in Example 2 of the present invention.

[0033] Figure 11 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0034] Figure 12 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0035] Figure 13 Graph showing the F-Theta distortion of the optical lens in Example 3 of the present invention.

[0036] Figure 14 Graph showing vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0037] Figure 15 This is a relative illumination curve diagram of the optical lens in Example 3 of the present invention.

[0038] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0039] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of embodiments of the present application and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of the present invention.

[0041] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0042] In this article, the paraxial region refers to the area near the optical axis. If a lens surface is convex and the location of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the location of the concave surface is undefined, 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.

[0043] It should also be understood that the terms "comprises," "including," "having," "includes," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application." And, the term "exemplary" is intended to refer to an example or illustration.

[0044] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0045] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] The optical lens provided by the embodiment of the present invention has a total of five lenses, which are, in order from the object side to the imaging surface along the optical axis, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens. The optical lens provided by the present invention is an infrared lens, which is a lens specifically used to capture infrared light.

[0047] In some embodiments, the first lens may have a negative optical power, its object side is convex, and its image side is concave. The second lens may have a positive optical power, its object side is convex, and its image side may be concave or convex. The third lens may have a positive optical power, its object side is convex near the optical axis, and its image side is convex. The fourth lens may have a negative optical power, its object side is concave, and its image side is convex. The fifth lens may have a positive optical power, its object side is convex near the optical axis, and its image side is concave.

[0048] In some embodiments, the optical lens may further include an aperture stop, and the aperture stop may be located between the first lens and the second lens. It can be understood that the aperture stop is used to limit the amount of incident light to change the brightness of the image. When the aperture stop is located between the first lens and the second lens, it is convenient for correcting the aperture aberration.

[0049] In some embodiments, the optical lens may further include a filter, and the filter may be disposed 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.

[0050] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 136° < FOV / Fno < 151°. Meeting the above range limits that the optical lens has a suitable field of view and aperture value, can collect light at a large angle and obtain good imaging quality. More specifically, 136.66° < FOV / Fno < 150.19°.

[0051] In some embodiments, the effective focal length f of the optical lens and the total optical length TTL of the optical lens satisfy: 3.7 < TTL / f < 4. Meeting the above conditions can not only achieve the characteristics of a large target surface and a large viewing angle of the lens, so as to meet the local shooting requirements and be able to match a larger size chip, but also achieve high-pixel imaging of the lens, improving the lens resolution and the receiving field of view. More specifically, 3.72 < TTL / f < 3.98.

[0052] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 1.25 < TTL / IH < 1.4. Meeting the above range is beneficial to achieving the balance between the volume of the optical lens and the large image surface. More specifically, 1.29 < TTL / IH < 1.39.

[0053] In some embodiments, the effective focal length f of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the radian value θ of the maximum half-field angle of the optical lens satisfy: 0.99 < (IH / 2) / (f×θ) < 1.02. When the above range is satisfied, the optical distortion of the optical lens is well controlled, the resolution of the optical lens is improved, and a better imaging effect can be obtained.

[0054] In some embodiments, the overall 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: 1.4 < 180°×TTL / IH / FOV < 1.55. When the above range is satisfied, it is beneficial to balance the relationship among the overall length, image height, and field angle of the optical lens. More specifically, 1.42 < 180°×TTL / IH / FOV < 1.51.

[0055] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.1 < IH / EPD < 3.5. When the above range is satisfied, the width of the light beam entering the optical lens can be increased, the relative illumination can be improved, and vignetting can be avoided. More specifically, 3.14 < IH / EPD < 3.49.

[0056] In some embodiments, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.8 < IH / f < 3. When the above range is satisfied, it is helpful to achieve a large image plane and improve the imaging quality of the optical lens. More specifically, 2.85 < IH / f < 2.91.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.3 < f1 / f < -1.7; the effective focal length f of the optical lens and the object-side curvature radius R1 of the first lens satisfy: 13 < R1 / f < 446; the effective focal length f of the optical lens and the image-side curvature radius R2 of the first lens satisfy: 1.1 < R2 / f < 1.3. When the above range is satisfied, the first lens can have an appropriate negative optical power, the degree of deflection of the incident light can be reduced, it is helpful for light to enter the optical system within a larger range, and it is beneficial to expand the lens field angle. More specifically, -2.21 < f1 / f < -!78; 13.64 < R1 / f < 445.2; 1.1 < R2 / f < 1.26.

[0058] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1 < f3 / f < 1.4; the effective focal length f of the optical lens and the object-side curvature radius R5 of the third lens satisfy: 1.1 < R5 / f < 2.7; the effective focal length f of the optical lens and the image-side curvature radius R6 of the third lens satisfy: -1.3 < R6 / f < -1.1. The third lens is relatively sensitive in the entire optical system. Meeting the above ranges and reasonably defining the proportion of the optical power of the third lens and its surface shape are beneficial to improving the relative illumination of the optical lens. More specifically, 1.03 < f3 / f < 1.38; 1.14 < R5 / f < 2.64; -1.24 < R6 / f < -1.11.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -25.5 < f4 / f < -4.5; the effective focal length f of the optical lens and the object-side curvature radius R7 of the fourth lens satisfy: -0.9 < R7 / f < -0.4; the effective focal length f of the optical lens and the image-side curvature radius R8 of the fourth lens satisfy: -1.1 < R8 / f < -0.6. The fourth lens is relatively sensitive in the entire optical system. Meeting the above ranges and reasonably defining the proportion of the optical power of the fourth lens and its surface shape can be beneficial to controlling the field curvature and reducing the difficulty of aberration correction of the optical lens. More specifically, -25.44 < f4 / f < -4.57; -0.85 < R7 / f < -0.46; -1.09 < R8 / f < -0.67.

[0060] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 4 < f5 / f < 8; the effective focal length f of the optical lens and the object-side curvature radius R9 of the fifth lens satisfy: 0.7 < R9 / f < 1.3; the effective focal length f of the optical lens and the image-side curvature radius R10 of the fifth lens satisfy: 0.8 < R10 / f < 1.4. Meeting the above ranges and reasonably defining the proportion of the optical power of the fifth lens and its surface shape are beneficial to converging light while reducing the light deflection angle, enabling the light to transition smoothly, and improving the imaging quality of the optical lens. More specifically, 4.04 < f5 / f < 7.96; 0.77 < R9 / f < 1.27; 0.87 < R10 / f < 1.31.

[0061] In some embodiments, the focal length f1 of the first lens and the combined focal length f2345 of the second, third, fourth, and fifth lenses satisfy: -2.1 < f1 / f2345 < -1.7. Meeting the above ranges is beneficial to balancing the aberrations generated by the lens groups before and after the aperture and improving the imaging quality of the optical lens. More specifically, -2.08 < f1 / f2345 < -1.77.

[0062] 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: 0.95 < d1 / d10 < 1. Meeting the above range and reasonably matching the aperture ratio of the first lens and the fifth lens facilitates the structural design and helps to improve the imaging quality of the optical lens.

[0063] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -0.35 < f3 / f4 < 0; the central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 1 < CT3 / CT4 < 3. Meeting the above range can reduce the light deflection angle, make the light path more stable; at the same time, it can correct coma and field curvature, improve the flatness of imaging, and enhance the imaging quality of the optical lens. More specifically, -0.31 < f3 / f4 < -0.03; 1.04 < CT3 / CT4 < 2.97.

[0064] 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: 0.5 < ∑CT / TTL < 0.7. Meeting the above range can effectively compress the total length of the optical lens and is beneficial to the structural design and production process of the optical lens. More specifically, 0.55 < ∑CT / TTL < 0.67.

[0065] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis and the effective focal length f of the optical lens satisfy: 2.2 < ∑CT / f < 2.6. Meeting the above range can effectively correct the field curvature and distortion of the optical lens and improve the imaging quality of the optical lens. More specifically, 2.23 < ∑CT / f < 2.6.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 3.1 < f2 / f < 22.8. Meeting the above range can effectively converge light, ensure that the lens reduces the difficulty of correcting the edge field distortion while achieving a large field angle, and improve the overall imaging quality. More specifically, 3.13 < f2 / f < 22.75.

[0067] In some embodiments, the sagittal height Sag2 of the clear aperture semi-diameter of the image side surface of the first lens and the clear aperture semi-diameter d2 of the image side surface of the first lens satisfy: 0.45 < Sag2 / d2 < 0.51; the sagittal height Sag3 of the clear aperture semi-diameter of the object side surface of the second lens and the clear aperture semi-diameter d3 of the object side surface of the second lens satisfy: 0 < |Sag3 / d3| < 0.04. Meeting the above range helps to control the light path of the edge field and highlight the detailed information of the central field of the optical lens.

[0068] In some embodiments, the optical lens satisfies the conditional formula: 1.4 mm < f < 1.5 mm, 1.2 mm < EPD < 1.4 mm, 5.5 mm < TTL < 5.8 mm, 1.05 < Fno < 1.25, 26° < CRA < 30°, 0.9 mm < BFL < 1.2 mm, 163° < FOV < 166°, 4 mm < IH < 4.3 mm; where f represents the effective focal length of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, CRA represents the chief ray angle of incidence at the maximum image height of the optical lens, BFL represents the back focal length of the optical lens, FOV represents the maximum field angle of the optical lens, and IH represents the true image height corresponding to the maximum field angle of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention at least has characteristics such as a large aperture, a large field angle, and a large target surface. More specifically, 1.41 mm < f < 1.5 mm, 1.2 mm < EPD < 1.36 mm, 5.53 mm < TTL < 5.72 mm, 1.09 < Fno < 1.21, 26.69° < CRA < 29.28°, 0.98 mm < BFL < 1.18 mm, 163.9° < FOV < 165.3°, 4.08 mm < IH < 4.26 mm.

[0069] 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. Additionally, when the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present invention can adopt an all-plastic lens structure, which not only enables the lens to have excellent imaging performance, but also makes the lens structure relatively compact, and can better achieve the balance of lens miniaturization and high image quality.

[0070] 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 realizing lens miniaturization. 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.

[0071] In each embodiment of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0072] ;

[0073] Where z is the distance between the surface and the vertex in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the surface vertex, K is the quadratic surface coefficient, and B, C, D, E, F, G, and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients, respectively.

[0074] The present invention is further illustrated below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens vary; for details, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any other changes, substitutions, combinations, or simplifications that do not deviate from the novelties of the present invention shall be considered equivalent replacements and are included within the scope of protection of the present invention.

[0075] Example 1

[0076] See also Figure 1 , shown is a schematic structural diagram of the optical lens 100 provided in Example 1 of the present invention, which includes, along the optical axis from the object side to the imaging surface, 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.

[0077] The first lens L1 has negative refractive power, its object-side surface S1 is convex, and its image-side surface S2 is concave;

[0078] The second lens L2 has positive refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave near the optical axis;

[0079] The third lens L3 has positive refractive power, its object-side surface S5 is convex near the optical axis, and its image-side surface S6 is convex;

[0080] The fourth lens L4 has negative refractive power, its object-side surface S7 is concave, and its image-side surface S8 is convex;

[0081] The fifth lens L5 has positive refractive power, its object-side surface S9 is convex near the optical axis, and its image-side surface S10 is concave;

[0082] The object-side surface S11 and the image-side surface S12 of the filter G1 are both flat surfaces;

[0083] The imaging surface S13 is a plane.

[0084] 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.

[0085] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0086] Table 1-1

[0087]

[0088] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0089] Table 1-2

[0090]

[0091] In this embodiment, the field curvature curve, F-Theta distortion curve, vertical axis chromatic aberration curve, and relative illumination curve of the optical lens 100 are shown in FIG. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 shown.

[0092] Figure 2 The following figure shows the field curvature curve of Example 1, which shows the field 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 angle (unit: degrees). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.17mm, indicating that the optical lens 100 can effectively correct field curvature in the infrared band.

[0093] Figure 3 The following graph shows the F-Theta distortion curve for Example 1, which represents the F-Theta distortion at different image heights on the imaging plane. The horizontal axis represents the F-Theta distortion value (unit: %), and the vertical axis represents the half field of view angle (unit: °). As can be seen from the graph, the F-Theta distortion of the optical lens 100 is controlled within 0-5%, indicating that the optical lens 100 has achieved good distortion correction in the infrared band.

[0094] Figure 4 A vertical chromatic aberration curve for Example 1 is shown. It plots the chromatic aberration of each wavelength relative to the center wavelength (0.94 μm) at different image heights on the imaging plane. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the field of view angle. As can be seen from the graph, the vertical chromatic aberration for both the longest and shortest wavelengths is controlled within ±3 μm, demonstrating that the optical lens 100 is capable of excellently correcting chromatic aberration across all viewing angles in the infrared band.

[0095] Figure 5 A relative illumination curve for Example 1 is shown, showing relative illumination values at different field angles on the imaging plane. The horizontal axis represents the field angle (unit: degrees), and the vertical axis represents the relative illumination. As can be seen from the graph, the relative illumination value of the optical lens is still greater than 35% at the maximum half field angle, indicating that the optical lens 100 has good relative illumination in the infrared band.

[0096] Example 2

[0097] See also Figure 6 , shown is a schematic structural diagram of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[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

[0100]

[0101] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0102] Table 2-2

[0103]

[0104] In this embodiment, the field curvature curve, F-Theta distortion curve, vertical axis chromatic aberration curve, and relative illumination curve of the optical lens 200 are shown in FIG. Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 shown.

[0105] from Figure 7 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.15 mm, indicating that the optical lens 200 can well correct the field curvature in the infrared band.

[0106] from Figure 8 It can be seen from the figure that the F-Theta distortion of the optical lens 200 is controlled within -2%~4%, indicating that the distortion of the optical lens 200 in the infrared band is well corrected.

[0107] from Figure 9 As can be seen from the figure, the vertical chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±4 μm, indicating that the optical lens 200 can extremely well correct the chromatic aberration of each field of view in the infrared band.

[0108] from Figure 10 It can be seen that the relative illumination value of the optical lens is still greater than 30% at the maximum half field of view angle, indicating that the optical lens 200 has good relative illumination in the infrared band.

[0109] Example 3

[0110] See also Figure 11, shown is a schematic structural diagram of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main differences of this embodiment are: the image-side surface S4 of the second lens L2 is convex; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0111] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0112] Table 3-1

[0113]

[0114] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0115] Table 3-2

[0116]

[0117] In this embodiment, the field curvature curve, F-Theta distortion curve, vertical axis chromatic aberration curve, and relative illumination curve of the optical lens 300 are shown as follows: Figure 12 、 Figure 13 、 Figure 14 、 Figure 15 shown.

[0118] from Figure 12 It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.15 mm, indicating that the optical lens 300 can well correct the field curvature in the infrared band.

[0119] from Figure 13 It can be seen from the figure that the F-Theta distortion of the optical lens 300 is controlled within -2%~8%, indicating that the distortion of the optical lens 300 in the infrared band is well corrected.

[0120] from Figure 14 As can be seen from the figure, the vertical chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2μm, indicating that the optical lens 300 can extremely well correct the chromatic aberration of each field of view in the infrared band.

[0121] from Figure 15 It can be seen that the relative illumination value of the optical lens is still greater than 38% at the maximum half field of view angle, indicating that the optical lens 300 has good relative illumination in the infrared band.

[0122] Please refer to Table 4, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, real image height IH corresponding to the maximum field of view angle, chief ray incidence angle CRA at the maximum image height, maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0123] Table 4

[0124]

[0125] In summary of the above embodiments, the optical lens provided by the present invention has at least the following advantages:

[0126] (1) Through specific surface shape settings and reasonable optical focal length distribution, the lens has a large aperture. When the optical lens is imaging in a dark environment, the noise caused by weak light can be reduced, thereby improving the imaging quality; ensuring large target surface imaging, while controlling the number of lenses (5p), reducing the difficulty of lens processing and improving mass production.

[0127] (2) The optical lens of the present invention can reasonably correct the overall aberration of the optical lens, the overall lens aberration is small, the structure is compact, and the imaging quality of the optical lens is improved.

[0128] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations 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 any one or more embodiments or examples.

[0129] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An optical lens, comprising five lenses, characterized in that: It successively 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 convex and whose image side is concave; A second lens with a positive optical power, whose object side is convex; A third lens with a positive optical power, whose object side is convex near the optical axis and whose image side is convex; A fourth lens with a negative optical power, whose object side is concave and whose image side is convex; A fifth lens with a positive optical power, whose object side is convex near the optical axis and whose image side is concave; Wherein, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 136° < FOV / Fno < 151°; 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: 1.4 < 180°×TTL / IH / FOV < 1.55; the effective focal length f of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens and the radian value θ of the maximum half field angle of the optical lens satisfy: 0.99 < (IH / 2) / (f×θ) < 1.

02.

2. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the total optical length TTL of the optical lens satisfy: 3.7 < TTL / f < 4; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 1.25 < TTL / IH < 1.

4.

3. The optical lens according to claim 1, wherein: The maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 136.66° < FOV / Fno < 150.19°; 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: 1.42 < 180°×TTL / IH / FOV < 1.

51.

4. The optical lens according to claim 1, wherein: The true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.1 < IH / EPD < 3.5; the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.8 < IH / f < 3.

5. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.3 < f1 / f < -1.7; the effective focal length f of the optical lens and the object side curvature radius R1 of the first lens satisfy: 13 < R1 / f < 446; the effective focal length f of the optical lens and the image side curvature radius R2 of the first lens satisfy: 1.1 < R2 / f < 1.

3.

6. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1 < f3 / f < 1.4; the effective focal length f of the optical lens and the object side curvature radius R5 of the third lens satisfy: 1.1 < R5 / f < 2.7; the effective focal length f of the optical lens and the image side curvature radius R6 of the third lens satisfy: -1.3 < R6 / f < -1.

1.

7. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -25.5 < f4 / f < -4.5; the effective focal length f of the optical lens and the object-side curvature radius R7 of the fourth lens satisfy: -0.9 < R7 / f < -0.4; the effective focal length f of the optical lens and the image-side curvature radius R8 of the fourth lens satisfy: -1.1 < R8 / f < -0.

6.

8. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 4 < f5 / f < 8; the effective focal length f of the optical lens and the object-side curvature radius R9 of the fifth lens satisfy: 0.7 < R9 / f < 1.3; the effective focal length f of the optical lens and the image-side curvature radius R10 of the fifth lens satisfy: 0.8 < R10 / f < 1.

4.

9. The optical lens according to claim 1, wherein: The focal length f1 of the first lens and the combined focal length f2345 of the second lens, the third lens, the fourth lens and the fifth lens satisfy: -2.1 < f1 / f2345 < -1.7; the object-side clear aperture radius d1 of the first lens and the image-side clear aperture radius d10 of the fifth lens satisfy: 0.95 < d1 / d10 < 1.

10. The optical lens according to claim 1, wherein: The focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -0.35 < f3 / f4 < 0; the central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 1 < CT3 / CT4 < 3.

Images