Optical lens

Abstract

The present application discloses an optical lens, which comprises, from the object side to the image side along the optical axis, a first lens with positive optical power, a second lens with negative optical power, a third lens with positive optical power, a fourth lens with positive optical power, a fifth lens with negative optical power, a sixth lens with positive optical power, a seventh lens with negative optical power, an eighth lens with positive optical power, and a ninth lens with negative optical power; wherein the object side surface of the seventh lens is a concave surface, and the image side surface is a convex surface; the object side surface of the eighth lens is a concave surface, and the image side surface is a convex surface.

Description

Technical Field

[0001] The present application relates to the field of optical elements, and in particular to an optical lens. Background Art

[0002] With the continuous development of optical lens technology, optical lenses are being used more and more widely. For example, optical lenses play an important role in many fields such as industry, textile industry, macro photography, and drone photography. The market's requirements for the imaging quality of these lenses are also getting higher and higher. Important indicators for measuring the imaging quality of optical lenses include resolution, distortion, and relative illumination. Among them, resolution reflects the ability of the optical lens to distinguish image details, distortion mainly reflects the degree of distortion of the image, and relative illumination refers to the ratio of the edge illumination to the center illumination of the imaging surface of the optical lens, which reflects the uniformity of the brightness of the image. Summary of the invention

[0003] The present application provides an optical lens, which includes, from the object side to the image side along the optical axis: a first lens with positive optical power, a second lens with negative optical power, a third lens with positive optical power, a fourth lens with positive optical power, a fifth lens with negative optical power, a sixth lens with positive optical power, a seventh lens with negative optical power, an eighth lens with positive optical power, and a ninth lens with negative optical power; wherein the object side surface of the seventh lens is a concave surface, and the image side surface is a convex surface; the object side surface of the eighth lens is a concave surface, and the image side surface is a convex surface.

[0004] According to an exemplary embodiment of the present application, the optical lens satisfies: 1.28≤|f1×(DR11-DR12) / f|≤1.76, wherein f1 is the effective focal length of the first lens, f is the total effective focal length of the optical lens, DR11 is the full effective aperture of the object side of the first lens, and DR12 is the full effective aperture of the image side of the first lens.

[0005] According to an exemplary embodiment of the present application, the optical lens satisfies: 1.63≤|f2×(DR21-DR22) / f|≤2.09, wherein f2 is the effective focal length of the second lens, f is the total effective focal length of the optical lens, DR21 is the full effective aperture of the object side of the second lens, and DR22 is the full effective aperture of the image side of the second lens.

[0006] According to an exemplary embodiment of the present application, the effective focal length f3 of the third lens, the refractive index Nd3 of the third lens and the total effective focal length f of the optical lens satisfy: 1.53≤|f3×Nd3 / f|≤1.93.

[0007] According to an exemplary embodiment of the present application, the object side surface of the fourth lens is convex, and the image side surface is convex; the object side surface of the fifth lens is concave, and the image side surface is concave; the fourth lens and the fifth lens are cemented to form a cemented lens.

[0008] According to an exemplary embodiment of the present application, the Abbe number Vd4 of the fourth lens, the Abbe number Vd5 of the fifth lens, and the combined effective focal length fB1 of the fourth lens and the fifth lens satisfy: -0.07≤(Vd4-Vd5) / fB1≤-0.01.

[0009] According to an exemplary embodiment of the present application, the effective focal length f6 of the sixth lens and the effective focal length f7 of the seventh lens satisfy: -0.42≤f6 / f7≤-0.31.

[0010] According to an exemplary embodiment of the present application, the combined effective focal length f89 of the eighth lens and the ninth lens and the total effective focal length f of the optical lens satisfy: -0.93≤f89 / f≤-0.72.

[0011] According to an exemplary embodiment of the present application, a combined effective focal length f17 of the first to seventh lenses and a combined effective focal length f89 of the eighth and ninth lenses satisfy: -1.02≤f17 / f89≤-0.80.

[0012] According to an exemplary embodiment of the present application, the optical lens satisfies: -0.18≤(SM92-SN92) / (SM91-SN91)≤-0.13, wherein SM92 is the maximum sag of the image side surface of the ninth lens, SN92 is the minimum sag of the image side surface of the ninth lens, SM91 is the maximum sag of the object side surface of the ninth lens, and SN91 is the minimum sag of the object side surface of the ninth lens.

[0013] According to an exemplary embodiment of the present application, the object side surface of the first lens is convex, and the image side surface is concave; the object side surface of the second lens is concave, and the image side surface is concave; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the sixth lens is convex, and the image side surface is convex; the object side surface of the ninth lens is concave, and the image side surface is concave.

[0014] According to an exemplary embodiment of the present application, the effective focal length f8 of the eighth lens, the half image height IH of the optical lens, and the total effective focal length f of the optical lens satisfy: 15.84≤f8×IH / f≤24.88.

[0015] According to an exemplary embodiment of the present application, the effective focal length f9 of the ninth lens, the half image height IH of the optical lens, and the total effective focal length f of the optical lens satisfy: -4.44≤f9×IH / f≤-3.45.

[0016] According to an exemplary embodiment of the present application, the effective focal length f1 of the first lens, the refractive index Nd1 of the first lens and the total effective focal length f of the optical lens satisfy: 2.39≤|f1×Nd1 / f|≤2.99.

[0017] According to an exemplary embodiment of the present application, the effective focal length f2 of the second lens and the total effective focal length f of the optical lens satisfy: 1.06≤|f2 / f|≤1.30.

[0018] According to an exemplary embodiment of the present application, the effective focal length f3 of the third lens and the total effective focal length f of the optical lens satisfy: 0.99≤|f3 / f|≤1.25.

[0019] According to an exemplary embodiment of the present application, the effective focal length f6 of the sixth lens and the total effective focal length f of the optical lens satisfy: 0.76≤|f6 / f|≤0.97.

[0020] According to an exemplary embodiment of the present application, the effective focal length f7 of the seventh lens and the total effective focal length f of the optical lens satisfy: 2.01≤|f7 / f|≤2.81. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings, in which:

[0022] Figure 1 A schematic structural diagram of an optical lens according to Embodiment 1 of the present application is shown;

[0023] Figure 2 A schematic structural diagram of an optical lens according to Embodiment 2 of the present application is shown;

[0024] Figure 3 A schematic structural diagram of an optical lens according to Embodiment 3 of the present application is shown;

[0025] Figure 4 A schematic structural diagram of an optical lens according to Embodiment 4 of the present application is shown;

[0026] Figure 5 A schematic structural diagram of an optical lens according to Example 5 of the present application is shown. DETAILED DESCRIPTION

[0027] In order to better understand the present application, various aspects of the present application are described in detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and do not limit the scope of the present application in any way.

[0028] In the 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 shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0029] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface 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 position of the concave surface 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 object is called the object side of the lens, and the surface of each lens closest to the image plane is called the image side of the lens.

[0030] It should also be understood that the terms "include", "comprising", "having", "including" 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. It should be noted that in this specification, the expressions first, second, third, etc. are only used to distinguish one feature from another, and do not represent any limitation on the features.

[0031] Unless otherwise defined, all terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. Terms should be interpreted as having the same meaning as they have in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0032] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present 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.

[0033] The present application provides an optical lens, which includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens in sequence from the object side to the image side along the optical axis.

[0034] In an exemplary embodiment, the first lens has positive refractive power, and its object-side surface is convex and its image-side surface is concave, which is beneficial for correcting the field curvature of the optical lens.

[0035] In an exemplary embodiment, the second lens has negative optical power, and its object side surface is concave and its image side surface is concave, which is beneficial to correcting the field curvature and distortion of the optical lens.

[0036] In an exemplary embodiment, the third lens has positive optical power, its object side surface is convex, and its image side surface is convex, which can compensate for the aberration of the front lens group to reduce the pressure of the rear lens group to correct the aberration, which is beneficial to improving the imaging quality of the optical lens.

[0037] In an exemplary embodiment, the fourth lens has positive power, its object side surface is convex, and its image side surface is convex; the fifth lens has negative power, its object side surface is concave, and its image side surface is concave, and the fourth lens and the fifth lens are cemented to form a cemented lens, which is not only conducive to correcting the chromatic aberration of the optical lens, thereby improving the imaging quality of the optical lens, but also can make the light transition smoothly, thereby reducing the field curvature and tolerance sensitivity of the optical lens, thereby improving the assembly yield of the optical lens. In addition, the fourth lens and the fifth lens are cemented to form a cemented lens, which can also shorten the total optical length of the optical lens and make the structure of the optical lens more compact.

[0038] In an exemplary embodiment, the seventh lens element has negative optical power, and its object-side surface is concave and its image-side surface is convex, which is beneficial for correcting the residual aberration of the optical lens.

[0039] In an exemplary embodiment, the sixth lens has positive optical power, its object side surface is convex, and its image side surface is convex. It is paired with the seventh lens with negative optical power in high and low temperature conditions to compensate the optical power to reduce or offset the defocus changes caused by different temperatures.

[0040] In an exemplary embodiment, the eighth lens has positive optical power, its object side surface is concave, and its image side surface is convex, which is beneficial to correcting the edge aberration of the optical lens, thereby increasing the image height and relative illumination of the optical lens, and further improving the imaging quality of the optical lens.

[0041] In an exemplary embodiment, the ninth lens has negative optical power, its object side surface is concave, and its image side surface is concave, which can correct the residual aberration and distortion of the optical lens, thereby increasing the image height and relative illumination of the optical lens, and further improving the imaging quality of the optical lens.

[0042] In an exemplary embodiment, by adjusting the interval between the seventh lens and the eighth lens, focusing adapted to different object distances can be achieved, and it is also beneficial to correct field curvature at different object distances. In this case, the optical lens is an inner focusing lens.

[0043] In an exemplary embodiment, the optical lens satisfies: 1.28≤|f1×(DR11-DR12) / f|≤1.76, wherein f1 is the effective focal length of the first lens, f is the total effective focal length of the optical lens, DR11 is the full effective aperture on the object side of the first lens, and DR12 is the full effective aperture on the image side of the first lens. The units of the effective focal length f1 of the first lens, the total effective focal length f of the optical lens, the full effective aperture DR11 on the object side of the first lens, and the full effective aperture DR12 on the image side of the first lens are all in millimeters (mm). Preferably, 1.4≤|f1×(DR11-DR12) / f|≤1.6. By rationally configuring the effective focal length of the first lens, the full effective aperture on the object side, and the full effective aperture on the image side, the height difference of the light can be increased, which is beneficial to reducing the field curvature and aberration of the optical lens.

[0044] In an exemplary embodiment, the effective focal length f1 of the first lens, the refractive index Nd1 of the first lens and the total effective focal length f of the optical lens satisfy: 2.39≤|f1×Nd1 / f|≤2.99. Preferably, 2.66≤|f1×Nd1 / f|≤2.72. By properly configuring the effective focal length and refractive index of the first lens, the aperture size of the optical lens can be reduced, which is conducive to reducing the production cost of the optical lens.

[0045] In an exemplary embodiment, the optical lens satisfies: 1.63≤|f2×(DR21-DR22) / f|≤2.09, wherein f2 is the effective focal length of the second lens, f is the total effective focal length of the optical lens, DR21 is the full effective aperture on the object side of the second lens, and DR22 is the full effective aperture on the image side of the second lens. The units of the effective focal length f2 of the second lens, the total effective focal length f of the optical lens, the full effective aperture DR21 on the object side of the second lens, and the full effective aperture DR22 on the image side of the second lens are all in millimeters (mm). Preferably, 1.81≤|f2×(DR21-DR22) / f|≤1.9. By reasonably configuring the effective focal length of the second lens, the full effective aperture on the object side, and the full effective aperture on the image side, the height difference of the light can be increased, the field curvature of the optical lens can be reduced, and the large field aberration of the optical lens can be reduced.

[0046] In an exemplary embodiment, the effective focal length f2 of the second lens and the total effective focal length f of the optical lens satisfy: 1.06≤|f2 / f|≤1.30. Preferably, 1.17≤|f2 / f|≤1.18. By properly configuring the effective focal length of the second lens, it is helpful to reduce the spherical aberration and distortion of the optical lens.

[0047] In an exemplary embodiment, the effective focal length f3 of the third lens, the refractive index Nd3 of the third lens and the total effective focal length f of the optical lens satisfy: 1.53≤|f3×Nd3 / f|≤1.93. Preferably, 1.69≤|f3×Nd3 / f|≤1.75. By properly configuring the effective focal length and refractive index of the third lens, it is beneficial to compress the light collected at the front end and make the light smoothly transition to the rear, which can compensate for the aberration of the front lens group.

[0048] In an exemplary embodiment, the effective focal length f3 of the third lens and the total effective focal length f of the optical lens satisfy: 0.99≤|f3 / f|≤1.25. Preferably, 1.1≤|f3 / f|≤1.14. By properly configuring the effective focal length of the third lens, it is helpful to reduce the spherical aberration and distortion of the optical lens.

[0049] In an exemplary embodiment, the fourth lens and the fifth lens are cemented to form a cemented lens, and the Abbe number Vd4 of the fourth lens, the Abbe number Vd5 of the fifth lens, and the combined effective focal length fB1 of the fourth lens and the fifth lens satisfy: -0.07≤(Vd4-Vd5) / fB1≤-0.01. The unit of the combined effective focal length fB1 of the fourth lens and the fifth lens is millimeter (mm). Preferably, -0.05≤(Vd4-Vd5) / fB1≤-0.02. By reasonably configuring the Abbe number of the fourth lens, the Abbe number of the fifth lens, and the combined effective focal length of the fourth lens and the fifth lens, the system chromatic aberration can be effectively corrected, which is beneficial to improving the resolution of the optical lens.

[0050] In an exemplary embodiment, the effective focal length f6 of the sixth lens and the effective focal length f7 of the seventh lens satisfy: -0.42≤f6 / f7≤-0.31. Preferably, -0.38≤f6 / f7≤-0.34. By rationally configuring the effective focal length of the sixth lens and the effective focal length of the seventh lens, it is beneficial to correct high and low temperatures to weaken or offset the defocus changes generated at different temperatures, while correcting the spherical aberration of the optical lens and improving the resolution of the optical lens.

[0051] In an exemplary embodiment, the effective focal length f6 of the sixth lens and the total effective focal length f of the optical lens satisfy: 0.76≤|f6 / f|≤0.97. Preferably, 0.84≤|f6 / f|≤0.89. By properly configuring the effective focal length of the sixth lens, it is beneficial to match it with the seventh lens having a negative optical power, to correct high and low temperatures to weaken or offset the defocus changes generated at different temperatures, and to compensate for the residual aberration of the front lens group.

[0052] In an exemplary embodiment, the effective focal length f7 of the seventh lens and the total effective focal length f of the optical lens satisfy: 2.01≤|f7 / f|≤2.81. Preferably, 2.2≤|f7 / f|≤2.6. By properly configuring the effective focal length of the seventh lens, it is helpful to improve the image height of the optical lens.

[0053] In an exemplary embodiment, the combined effective focal length f17 of the first to seventh lenses and the combined effective focal length f89 of the eighth and ninth lenses satisfy: -1.02≤f17 / f89≤-0.80. Preferably, -0.93≤f17 / f89≤-0.88. By reasonably configuring the combined effective focal length of the first to seventh lenses and the combined effective focal length of the eighth and ninth lenses, the change of the effective focal length of the optical lens at different object distances can be controlled when the optical lens is an inner focusing lens, and focus control at different object distances can be achieved.

[0054] In an exemplary embodiment, the combined effective focal length f89 of the eighth lens and the ninth lens and the total effective focal length f of the optical lens satisfy: -0.93≤f89 / f≤-0.72. Preferably, -0.85≤f89 / f≤-0.75. By properly configuring the combined effective focal length of the eighth lens and the ninth lens, a smooth transition of light can be achieved, the image height and relative illumination of the optical lens can be improved, and a large target surface can be achieved.

[0055] In an exemplary embodiment, the effective focal length f8 of the eighth lens, the half image height IH of the optical lens, and the total effective focal length f of the optical lens satisfy: 15.84≤f8×IH / f≤24.88. The units of the effective focal length f8 of the eighth lens, the half image height IH of the optical lens, and the total effective focal length f of the optical lens are all in millimeters (mm). Preferably, 17.5≤f8×IH / f≤22.7. By reasonably configuring the effective focal length of the eighth lens, the half image height of the optical lens, and the total effective focal length, the image height of the optical lens can be increased, which is conducive to achieving a large target surface.

[0056] In an exemplary embodiment, the effective focal length f9 of the ninth lens, the half image height IH of the optical lens, and the total effective focal length f of the optical lens satisfy: -4.44≤f9×IH / f≤-3.45. The units of the effective focal length f9 of the ninth lens, the half image height IH of the optical lens, and the total effective focal length f of the optical lens are all in millimeters (mm). Preferably, -4.10≤f9×IH / f≤-3.80. By rationally configuring the effective focal length of the ninth lens, the half image height of the optical lens, and the total effective focal length, the image height and relative illumination of the optical lens can be improved, which is conducive to achieving a large target surface.

[0057] In an exemplary embodiment, the optical lens satisfies: -0.18≤(SM92-SN92) / (SM91-SN91)≤-0.13, wherein SM92 is the maximum sagitta of the image side surface of the ninth lens, SN92 is the minimum sagitta of the image side surface of the ninth lens, SM91 is the maximum sagitta of the object side surface of the ninth lens, and SN91 is the minimum sagitta of the object side surface of the ninth lens. By rationally configuring the maximum sagitta and the minimum sagitta of the object side surface and the image side surface of the ninth lens, it is helpful to reduce the distortion of the optical lens.

[0058] In an exemplary embodiment, the first to ninth lenses may include at least one plastic lens and at least one glass lens. Preferably, the first to ninth lenses may include at least two continuous plastic lenses adjacent to the glass lens, and the arrangement direction from the above-mentioned glass lens to the above-mentioned plastic lens is the same as the direction of the optical lens from the object side to the image side along the optical axis, which is conducive to correcting high and low temperatures; for example, the fifth lens is a glass lens, and the sixth and seventh lenses are plastic lenses. Exemplarily, the first to ninth lenses include 3 glass lenses and 6 plastic lenses, such as the first lens, the fourth lens and the fifth lens are glass lenses, and the second lens, the third lens, and the sixth to ninth lenses are plastic lenses. In alternative embodiments, whether the first to ninth lenses specifically use plastic lenses or glass lenses can also be selected according to actual needs.

[0059] In an exemplary embodiment, the optical lens may further include an aperture, which may be disposed between the third lens and the fourth lens to effectively converge the amount of light entering the optical lens, reduce the maximum aperture of the lens group before and after the aperture, and shorten the total optical length of the optical lens. It should be noted that the position of the aperture disclosed herein is only an example and not a limitation. In alternative embodiments, the aperture may also be disposed at other positions according to actual needs. In the present application, the total optical length of the optical lens refers to the distance from the object side of the first lens to the image plane in the direction of the optical axis.

[0060] In an exemplary embodiment, the optical lens may further include a protective glass between the image side surface of the ninth lens and the image plane, and light from the object sequentially passes through the first lens to the ninth lens and the protective glass and is finally imaged on the image plane.

[0061] In an exemplary embodiment, the optical lens may further include a light shielding sheet, which may be disposed between the second lens and the third lens to intercept a portion of harmful light and reduce the influence of aberration on the resolution.

[0062] In the present application, any lens from the first lens to the ninth lens may be an aspherical lens or a spherical lens. The characteristic of an aspherical lens is that the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. An aspherical lens can eliminate the aberration that occurs during imaging as much as possible, thereby improving the imaging quality.

[0063] Unless otherwise specified, the total effective focal length f of the optical lens in this application refers to the total effective focal length of the optical lens when the object distance is 0.75m, and the half image height IH refers to the half image height of the optical lens when the object distance is 0.75m.

[0064] The optical lens provided in the present application can have at least one of the following characteristics: 8K high resolution, high relative illumination, low distortion, large chief ray incidence angle CRA, high temperature tolerance, meeting 0.3m-infinity working distance shooting, day and night confocality. The high temperature tolerance enables the optical lens to work continuously for a long time within the temperature range of -40~+80℃.

[0065] Those skilled in the art should understand that, without departing from the technical solution claimed in the present application, the number of lenses constituting the optical lens can be changed to obtain the various results and advantages described in this specification. For example, although eight lenses are described as an example in the embodiment, the optical lens is not limited to including eight lenses. If necessary, the optical lens may also include other numbers of lenses.

[0066] Specific embodiments of the optical lens applicable to the above-mentioned embodiments are further described below with reference to the accompanying drawings. Example 1

[0067] The following reference Figure 1 An optical lens according to Example 1 of the present application is described.

[0068] like Figure 1As shown, the optical lens includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8 and a ninth lens L9 in sequence from the object side to the image side along the optical axis. The fourth lens L4 and the fifth lens L5 are cemented together to form a cemented lens. Among them, the first lens L1 has positive focal power, the object side surface S1 is convex, and the image side surface S2 is concave; the second lens L2 has negative focal power, the object side surface S3 is concave, and the image side surface S4 is concave; the third lens L3 has positive focal power, the object side surface S6 is convex, and the image side surface S7 is convex; the fourth lens L4 has positive focal power, the object side surface S8 is convex, and the image side surface S9 is convex; the fifth lens L5 has negative focal power, the object side surface S9 is concave, and the image side surface S10 is concave; the sixth lens L6 has positive focal power, the object side surface S11 is convex, and the image side surface S12 is convex; the seventh lens L7 has negative focal power, the object side surface S13 is concave, and the image side surface S14 is convex; the eighth lens L8 has positive focal power, the object side surface S15 is concave, and the image side surface S16 is convex; the ninth lens L9 has negative focal power, the object side surface S17 is concave, and the image side surface S18 is concave. The optical lens further includes a light shield S5 between the second lens L2 and the third lens L3, a stop STOP between the third lens L3 and the fourth lens L4, and a protective glass CG between the ninth lens L9 and the image plane IMA. The protective glass CG includes an object side surface S19 and an image side surface S20, and light from the object passes through surfaces S1 to S20 in sequence and is finally imaged on the image plane IMA.

[0069] Table 1 shows the basic parameters of each lens in the optical lens of this embodiment when the object distance is 0.75m, wherein the units of the radius of curvature and thickness / distance are both millimeters (mm).

[0070] Table 1

[0071]

[0072] In this embodiment, the second lens L2, the third lens L3, the sixth lens L6 to the ninth lens L9 are all aspherical lenses, and the surface shape of the aspherical lenses is x The following aspheric formulas can be used but are not limited to:

[0073] (1)

[0074] in, xis the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 2 shows the cone coefficient k and the high-order coefficient A of each aspheric mirror surface S3-S4, S6-S7, S11-S18 that can be used in this embodiment. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 .

[0075] Table 2

[0076]

[0077] When the object distance is 0.75m, the aperture value FNO of the optical lens of this embodiment is 2.20, the distortion value DIST at the maximum image height is -2.00%, the relative illumination RI is 69.90%, the total optical length TTL is 19.08mm, and the half image height IH is 6.15mm.

[0078] The optical lens of the present embodiment can also expand the application scenario of the optical lens by means of internal focusing, and expand the object distance range of the optical lens to 0.3m to infinity: when the object distance is 0.3m, the air spacing distance T78 between the seventh lens L7 and the eighth lens L8 on the optical axis in the optical lens of the present embodiment is adjusted to 1.454mm; when the object distance is infinity, the air spacing distance T78 between the seventh lens L7 and the eighth lens L8 on the optical axis in the optical lens of the present embodiment is adjusted to 1.11mm. Example 2

[0079] The following reference Figure 2 An optical lens according to Example 2 of the present application is described.

[0080] like Figure 2As shown, the optical lens includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8 and a ninth lens L9 in sequence from the object side to the image side along the optical axis. The fourth lens L4 and the fifth lens L5 are cemented together to form a cemented lens. Among them, the first lens L1 has positive focal power, the object side surface S1 is convex, and the image side surface S2 is concave; the second lens L2 has negative focal power, the object side surface S3 is concave, and the image side surface S4 is concave; the third lens L3 has positive focal power, the object side surface S6 is convex, and the image side surface S7 is convex; the fourth lens L4 has positive focal power, the object side surface S8 is convex, and the image side surface S9 is convex; the fifth lens L5 has negative focal power, the object side surface S9 is concave, and the image side surface S10 is concave; the sixth lens L6 has positive focal power, the object side surface S11 is convex, and the image side surface S12 is convex; the seventh lens L7 has negative focal power, the object side surface S13 is concave, and the image side surface S14 is convex; the eighth lens L8 has positive focal power, the object side surface S15 is concave, and the image side surface S16 is convex; the ninth lens L9 has negative focal power, the object side surface S17 is concave, and the image side surface S18 is concave. The optical lens further includes a light shield S5 between the second lens L2 and the third lens L3, a stop STOP between the third lens L3 and the fourth lens L4, and a protective glass CG between the ninth lens L9 and the image plane IMA. The protective glass CG includes an object side surface S19 and an image side surface S20, and light from the object passes through surfaces S1 to S20 in sequence and is finally imaged on the image plane IMA.

[0081] Table 3 shows the basic parameters of each lens in the optical lens of this embodiment when the object distance is 0.75m, wherein the units of the radius of curvature and thickness / distance are both millimeters (mm).

[0082] Table 3

[0083]

[0084] In this embodiment, the second lens L2, the third lens L3, the sixth lens L6 to the ninth lens L9 are all aspherical lenses. Table 4 shows the cone coefficient k and the high-order coefficient A of each aspherical mirror surface S3-S4, S6-S7, S11-S18 that can be used in this embodiment. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 .

[0085] Table 4

[0086]

[0087] When the object distance is 0.75m, the aperture value FNO of the optical lens of this embodiment is 2.20, the distortion value DIST at the maximum image height is -2.00%, the relative illumination RI is 65.56%, the total optical length TTL is 19.25mm, and the half image height IH is 6.35mm.

[0088] The optical lens of the present embodiment can also expand the application scenario of the optical lens by means of internal focusing, and the object distance range of the optical lens is extended to 0.3m to infinity: when the object distance is 0.3m, the air spacing distance T78 between the seventh lens L7 and the eighth lens L8 on the optical axis in the optical lens of the present embodiment is adjusted to 1.564mm; when the object distance is infinity, the air spacing distance T78 between the seventh lens L7 and the eighth lens L8 on the optical axis in the optical lens of the present embodiment is adjusted to 1.212mm. Example 3

[0089] The following reference Figure 3 An optical lens according to Example 3 of the present application is described.

[0090] like Figure 3 As shown, the optical lens includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8 and a ninth lens L9 in sequence from the object side to the image side along the optical axis. The fourth lens L4 and the fifth lens L5 are cemented together to form a cemented lens. Among them, the first lens L1 has positive focal power, the object side surface S1 is convex, and the image side surface S2 is concave; the second lens L2 has negative focal power, the object side surface S3 is concave, and the image side surface S4 is concave; the third lens L3 has positive focal power, the object side surface S6 is convex, and the image side surface S7 is convex; the fourth lens L4 has positive focal power, the object side surface S8 is convex, and the image side surface S9 is convex; the fifth lens L5 has negative focal power, the object side surface S9 is concave, and the image side surface S10 is concave; the sixth lens L6 has positive focal power, the object side surface S11 is convex, and the image side surface S12 is convex; the seventh lens L7 has negative focal power, the object side surface S13 is concave, and the image side surface S14 is convex; the eighth lens L8 has positive focal power, the object side surface S15 is concave, and the image side surface S16 is convex; the ninth lens L9 has negative focal power, the object side surface S17 is concave, and the image side surface S18 is concave. The optical lens further includes a light shield S5 between the second lens L2 and the third lens L3, a stop STOP between the third lens L3 and the fourth lens L4, and a protective glass CG between the ninth lens L9 and the image plane IMA. The protective glass CG includes an object side surface S19 and an image side surface S20, and light from the object passes through surfaces S1 to S20 in sequence and is finally imaged on the image plane IMA.

[0091] Table 5 shows the basic parameters of each lens in the optical lens of this embodiment when the object distance is 0.75m, wherein the units of the radius of curvature and thickness / distance are both millimeters (mm).

[0092] Table 5

[0093]

[0094] In this embodiment, the second lens L2, the third lens L3, the sixth lens L6 to the ninth lens L9 are all aspherical lenses. Table 6 shows the cone coefficient k and the high-order coefficient A of each aspherical mirror surface S3-S4, S6-S7, S11-S18 that can be used in this embodiment. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 .

[0095] Table 6

[0096]

[0097] When the object distance is 0.75m, the aperture value FNO of the optical lens of this embodiment is 2.10, the distortion value DIST at the maximum image height is -2.00%, the relative illumination RI is 64.25%, the total optical length TTL is 19.39mm, and the half image height IH is 6.15mm.

[0098] The optical lens of the present embodiment can also expand the application scenario of the optical lens by means of internal focusing, and expand the object distance range of the optical lens to 0.3m to infinity: when the object distance is 0.3m, the air spacing distance T78 between the seventh lens L7 and the eighth lens L8 on the optical axis in the optical lens of the present embodiment is adjusted to 1.385mm; when the object distance is infinity, the air spacing distance T78 between the seventh lens L7 and the eighth lens L8 on the optical axis in the optical lens of the present embodiment is adjusted to 1.037mm. Example 4

[0099] The following reference Figure 4 An optical lens according to Example 4 of the present application is described.

[0100] like Figure 4As shown, the optical lens includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8 and a ninth lens L9 in sequence from the object side to the image side along the optical axis. The fourth lens L4 and the fifth lens L5 are cemented together to form a cemented lens. Among them, the first lens L1 has positive focal power, the object side surface S1 is convex, and the image side surface S2 is concave; the second lens L2 has negative focal power, the object side surface S3 is concave, and the image side surface S4 is concave; the third lens L3 has positive focal power, the object side surface S6 is convex, and the image side surface S7 is convex; the fourth lens L4 has positive focal power, the object side surface S8 is convex, and the image side surface S9 is convex; the fifth lens L5 has negative focal power, the object side surface S9 is concave, and the image side surface S10 is concave; the sixth lens L6 has positive focal power, the object side surface S11 is convex, and the image side surface S12 is convex; the seventh lens L7 has negative focal power, the object side surface S13 is concave, and the image side surface S14 is convex; the eighth lens L8 has positive focal power, the object side surface S15 is concave, and the image side surface S16 is convex; the ninth lens L9 has negative focal power, the object side surface S17 is concave, and the image side surface S18 is concave. The optical lens further includes a light shield S5 between the second lens L2 and the third lens L3, a stop STOP between the third lens L3 and the fourth lens L4, and a protective glass CG between the ninth lens L9 and the image plane IMA. The protective glass CG includes an object side surface S19 and an image side surface S20, and light from the object passes through surfaces S1 to S20 in sequence and is finally imaged on the image plane IMA.

[0101] Table 7 shows the basic parameters of each lens in the optical lens of this embodiment when the object distance is 0.75m, wherein the units of the radius of curvature and thickness / distance are both millimeters (mm).

[0102] Table 7

[0103]

[0104] In this embodiment, the second lens L2, the third lens L3, the sixth lens L6 to the ninth lens L9 are all aspherical lenses. Table 8 shows the cone coefficient k and the high-order coefficient A of each aspherical mirror surface S3-S4, S6-S7, S11-S18 that can be used in this embodiment. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 .

[0105] Table 8

[0106]

[0107] When the object distance is 0.75m, the aperture value FNO of the optical lens of this embodiment is 2.00, the distortion value DIST at the maximum image height is -2.00%, the relative illumination RI is 61.82%, the total optical length TTL is 19.47mm, and the half image height IH is 6.15mm.

[0108] The optical lens of the present embodiment can also expand the application scenario of the optical lens by means of internal focusing, and expand the object distance range of the optical lens to 0.3m to infinity: when the object distance is 0.3m, the air spacing distance T78 between the seventh lens L7 and the eighth lens L8 on the optical axis in the optical lens of the present embodiment is adjusted to 1.332mm; when the object distance is infinity, the air spacing distance T78 between the seventh lens L7 and the eighth lens L8 on the optical axis in the optical lens of the present embodiment is adjusted to 0.984mm. Example 5

[0109] The following reference Figure 5 An optical lens according to Example 5 of the present application is described.

[0110] like Figure 5 As shown, the optical lens includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8 and a ninth lens L9 in sequence from the object side to the image side along the optical axis. The fourth lens L4 and the fifth lens L5 are cemented together to form a cemented lens. Among them, the first lens L1 has positive focal power, the object side surface S1 is convex, and the image side surface S2 is concave; the second lens L2 has negative focal power, the object side surface S3 is concave, and the image side surface S4 is concave; the third lens L3 has positive focal power, the object side surface S6 is convex, and the image side surface S7 is convex; the fourth lens L4 has positive focal power, the object side surface S8 is convex, and the image side surface S9 is convex; the fifth lens L5 has negative focal power, the object side surface S9 is concave, and the image side surface S10 is concave; the sixth lens L6 has positive focal power, the object side surface S11 is convex, and the image side surface S12 is convex; the seventh lens L7 has negative focal power, the object side surface S13 is concave, and the image side surface S14 is convex; the eighth lens L8 has positive focal power, the object side surface S15 is concave, and the image side surface S16 is convex; the ninth lens L9 has negative focal power, the object side surface S17 is concave, and the image side surface S18 is concave. The optical lens further includes a light shield S5 between the second lens L2 and the third lens L3, a stop STOP between the third lens L3 and the fourth lens L4, and a protective glass CG between the ninth lens L9 and the image plane IMA. The protective glass CG includes an object side surface S19 and an image side surface S20, and light from the object passes through surfaces S1 to S20 in sequence and is finally imaged on the image plane IMA.

[0111] Table 9 shows the basic parameters of each lens in the optical lens of this embodiment when the object distance is 0.75m, wherein the units of the radius of curvature and thickness / distance are both millimeters (mm).

[0112] Table 9

[0113]

[0114] In this embodiment, the second lens L2, the third lens L3, the sixth lens L6 to the ninth lens L9 are all aspherical lenses. Table 10 shows the cone coefficient k and the high-order coefficient A of each aspherical mirror surface S3-S4, S6-S7, S11-S18 that can be used in this embodiment. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 .

[0115] Table 10

[0116]

[0117] When the object distance is 0.75m, the aperture value FNO of the optical lens of this embodiment is 2.40, the distortion value DIST at the maximum image height is -2.00%, the relative illumination RI is 62.57%, the total optical length TTL is 19.30mm, and the half image height IH is 6.35mm.

[0118] The optical lens of the present embodiment can also expand the application scenario of the optical lens by means of internal focusing, and expand the object distance range of the optical lens to 0.3m to infinity: when the object distance is 0.3m, the air spacing distance T78 between the seventh lens L7 and the eighth lens L8 on the optical axis in the optical lens of the present embodiment is adjusted to 1.564mm; when the object distance is infinity, the air spacing distance T78 between the seventh lens L7 and the eighth lens L8 on the optical axis in the optical lens of the present embodiment is adjusted to 1.208mm.

[0119] In summary, the conditional expressions in Examples 1 to 5 satisfy the relationship shown in Table 11.

[0120] Table 11

[0121]

[0122] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. An optical lens, characterized in that: Along the optical axis from the object side to the image side, it includes: a first lens having positive optical power; a second lens having negative optical power; a third lens having positive refractive power; a fourth lens having positive refractive power; a fifth lens having negative optical power; a sixth lens having positive refractive power; The seventh lens element has a negative optical power, and its object side surface is concave and its image side surface is convex; an eighth lens element having positive refractive power, whose object-side surface is concave and whose image-side surface is convex; and a ninth lens having negative optical power; Wherein, the optical lens has nine lenses with optical power; The effective focal length f8 of the eighth lens, the half image height IH of the optical lens and the total effective focal length f of the optical lens satisfy: 15.84mm≤f8×IH / f≤24.88mm.

2. The optical lens according to claim 1, characterized in that: The optical lens satisfies: 1.28mm≤|f1×(DR11-DR12) / f|≤1.76mm, wherein f1 is the effective focal length of the first lens, f is the total effective focal length of the optical lens, DR11 is the full effective aperture of the object side of the first lens, and DR12 is the full effective aperture of the image side of the first lens.

3. The optical lens according to claim 1, characterized in that: The optical lens satisfies: 1.63mm≤|f2×(DR21-DR22) / f|≤2.09mm, wherein f2 is the effective focal length of the second lens, f is the total effective focal length of the optical lens, DR21 is the full effective aperture of the object side of the second lens, and DR22 is the full effective aperture of the image side of the second lens.

4. The optical lens according to claim 1, characterized in that: The effective focal length f3 of the third lens, the refractive index Nd3 of the third lens and the total effective focal length f of the optical lens satisfy: 1.53≤|f3×Nd3 / f|≤1.

93.

5. The optical lens according to claim 1, characterized in that: The object side surface of the fourth lens is convex, and the image side surface is convex; the object side surface of the fifth lens is concave, and the image side surface is concave; the fourth lens and the fifth lens are cemented to form a cemented lens.

6. The optical lens according to claim 1, characterized in that: The Abbe number Vd4 of the fourth lens, the Abbe number Vd5 of the fifth lens and the combined effective focal length fB1 of the fourth lens and the fifth lens satisfy: -0.07 mm -1 ≤(Vd4-Vd5) / fB1≤-0.01mm -1 .

7. The optical lens according to claim 1, characterized in that: The effective focal length f6 of the sixth lens and the effective focal length f7 of the seventh lens satisfy: -0.42≤f6 / f7≤-0.

31.

8. The optical lens according to claim 1, characterized in that: The combined effective focal length f89 of the eighth lens and the ninth lens and the total effective focal length f of the optical lens satisfy the following: -0.93≤f89 / f≤-0.

72.

9. The optical lens according to claim 1, characterized in that: The optical lens satisfies: -0.18≤(SM92-SN92) / (SM91-SN91)≤-0.13, wherein SM92 is the maximum sagitta of the image side surface of the ninth lens, SN92 is the minimum sagitta of the image side surface of the ninth lens, SM91 is the maximum sagitta of the object side surface of the ninth lens, and SN91 is the minimum sagitta of the object side surface of the ninth lens.

10. The optical lens according to claim 1, characterized in that: The object side surface of the first lens is convex, and the image side surface is concave; the object side surface of the second lens is concave, and the image side surface is concave; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the sixth lens is convex, and the image side surface is convex; the object side surface of the ninth lens is concave, and the image side surface is concave.

11. The optical lens according to any one of claims 1 to 10, characterized in that: A combined effective focal length f17 of the first to seventh lenses and a combined effective focal length f89 of the eighth and ninth lenses satisfy: -1.02≤f17 / f89≤-0.

80.

12. The optical lens according to any one of claims 1 to 10, characterized in that: The effective focal length f9 of the ninth lens, the half image height IH of the optical lens and the total effective focal length f of the optical lens satisfy: -4.44mm≤f9×IH / f≤-3.45mm.

13. The optical lens according to any one of claims 1 to 10, characterized in that: The effective focal length f1 of the first lens, the refractive index Nd1 of the first lens and the total effective focal length f of the optical lens satisfy: 2.39≤|f1×Nd1 / f|≤2.

99.

14. The optical lens according to any one of claims 1 to 10, characterized in that: The effective focal length f2 of the second lens and the total effective focal length f of the optical lens satisfy the following: 1.06≤|f2 / f|≤1.

30.

15. The optical lens according to any one of claims 1 to 10, characterized in that: The effective focal length f3 of the third lens and the total effective focal length f of the optical lens satisfy the following: 0.99≤|f3 / f|≤1.

25.

16. The optical lens according to any one of claims 1 to 10, characterized in that: The effective focal length f6 of the sixth lens and the total effective focal length f of the optical lens satisfy: 0.76≤|f6 / f|≤0.

97.

17. The optical lens according to any one of claims 1 to 10, characterized in that: The effective focal length f7 of the seventh lens and the total effective focal length f of the optical lens satisfy the following: 2.01≤|f7 / f|≤2.81.

Images