Image capturing optical lens

Abstract

To provide an image capturing optical lens which offers superior optical performance and meets the design requirements of a large aperture, extra thinness, and a wider angle of view.SOLUTION: An image capturing optical lens disclosed herein consists of a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, a fourth lens having positive refractive power, a fifth lens having positive refractive power, a sixth lens having negative refractive power, and a seventh lens having positive refractive power, arranged in order from the object side to the image side, and satisfies the following conditional expressions: -6.50≤f5 / f6≤-2.30, 0.035≤d6 / TTL≤0.055, and -3.50≤R7 / R8≤-1.80, where f5 represents a focal length of the fifth lens, f6 represents a focal length of the sixth lens, d6 represents an optical axial distance between the third lens and the fourth lens, TTL represents a total optical length of the image capturing optical lens, R7 represents a central curvature radius of an object-side surface of the fourth lens, and R8 represents a central curvature radius of an image-side surface of the fourth lens.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of optical lenses, and more particularly to an imaging optical lens that can be applied to imaging devices such as mobile terminal devices such as smartphones and digital cameras, surveillance cameras, PC cameras, and vehicle-mounted lenses. [Background technology]

[0002] In recent years, the rise of various smart devices has led to an increasing demand for compact imaging optical lenses. As the pixel size of photosensitive elements has become smaller, modern electronic products tend to be more functional, thinner, lighter, and more portable, resulting in the market trend toward compact imaging optical lenses with excellent image quality. To achieve better image quality, multi-lens structures are increasingly adopted. Furthermore, with technological developments and increasingly diverse user needs, the pixel area of photosensitive elements has been shrinking, and the demands for system imaging quality have continued to rise. As a result, seven-lens structures have gradually emerged in lens design. There is a demand for wide-angle imaging lenses that offer excellent optical performance, a small volume, and sufficient aberration correction. Summary of the Invention

[0003] In view of the above problems, an object of the present invention is to provide an imaging optical lens that has excellent optical performance and can satisfy design requirements for a large aperture, ultra-thinness, and wide angle.

[0004] In order to solve the above technical problems, according to an aspect of the present invention, an imaging optical lens is provided, which is composed of a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, a fourth lens having positive refractive power, a fifth lens having positive refractive power, a sixth lens having negative refractive power, and a seventh lens having positive refractive power, which are arranged in this order from an object side to an image side, and the focal length of the fifth lens is f5, is a focal length of the imaging optical lens is f6, the distance on the optical axis between the third lens and the fourth lens is d6, the total optical length of the imaging optical lens is TTL, the central radius of curvature of the object-side surface of the fourth lens is R7, the central radius of curvature of the image-forming side surface of the fourth lens is R8, and the above relational expressions of -6.50≦f5 / f6≦-2.30, 0.035≦d6 / TTL≦0.055, and -3.50≦R7 / R8≦-1.80 are satisfied.

[0005] Preferably, the distance from the seventh lens to the image plane is BFL, which satisfies the following relation: 0.15≦BFL / (TTL−BFL)≦0.25.

[0006] Preferably, the focal length of the seventh lens is f7, and the focal length of the imaging optical lens is f, satisfying the following relation: 1.50≦f7 / f≦2.50.

[0007] Preferably, the Abbe number of the fifth lens is v5, and the Abbe number of the sixth lens is v6, satisfying the following relational expression: 35.00≦v5−v6≦70.00.

[0008] Preferably, the refractive index of the first lens is n1, which satisfies the following relation: 1.70≦n1≦2.20.

[0009] Preferably, a portion of the object-side surface of the first lens close to the optical axis is a convex surface, a portion of the image-forming side surface of the first lens close to the optical axis is a concave surface, the focal length of the first lens is f1, the focal length of the imaging optical lens is f, the central curvature of the object-side surface of the first lens is R1, the central curvature of the image-forming side surface of the first lens is R2, and the thickness of the first lens on the optical axis is d1, and the following relations are satisfied: -6.18≦f1 / f≦-1.84, 0.83≦(R1+R2) / (R1-R2)≦2.99, 0.02≦d1 / TTL≦0.11

[0010] Preferably, a portion of the object-side surface of the second lens close to the optical axis is a convex surface, a portion of the image-side surface of the second lens close to the optical axis is a concave surface, the focal length of the second lens is f2, the focal length of the imaging optical lens is f, the central curvature of the object-side surface of the second lens is R3, the central curvature of the image-side surface of the second lens is R4, and the thickness of the second lens on the optical axis is d3, satisfying the following relations: -6.67≦f2 / f≦-1.98, 0.53≦(R3+R4) / (R3-R4)≦1.90, 0.003≦d3 / TTL≦0.06.

[0011] Preferably, a portion of the object-side surface of the third lens close to the optical axis is concave, a portion of the image-side surface of the third lens close to the optical axis is convex, the focal length of the third lens is f3, the focal length of the imaging optical lens is f, the central curvature of the object-side surface of the third lens is R5, the central curvature of the image-side surface of the third lens is R6, and the thickness of the third lens on the optical axis is d5, satisfying the following relational expressions: 2.66≦f3 / f≦8.82, 1.05≦(R5+R6) / (R5-R6)≦3.65, and 0.09≦d5 / TTL≦0.31.

[0012] Preferably, a portion of the object-side surface of the fourth lens close to the optical axis is convex, a portion of the image-forming side surface of the fourth lens close to the optical axis is convex, the focal length of the fourth lens is f4, the focal length of the imaging optical lens is f, and the thickness of the fourth lens on the optical axis is d7, satisfying the following relational expressions: 1.38≦f4 / f≦4.36, 0.03≦d7 / TTL≦0.14.

[0013] Preferably, a portion of the object-side surface of the fifth lens close to the optical axis is a convex surface, a portion of the image-side surface of the fifth lens close to the optical axis is a convex surface, the focal length of the fifth lens is f5, the focal length of the imaging optical lens is f, the central curvature of the object-side surface of the fifth lens is R9, the central curvature of the image-side surface of the fifth lens is R10, and the thickness of the fifth lens on the optical axis is d9, satisfying the following relational expressions: 1.87≦f5 / f≦17.58, -0.25≦(R9+R10) / (R9−R10)≦0.43, 0.04≦d9 / TTL≦0.15.

[0014] Preferably, a portion of the object-side surface of the sixth lens close to the optical axis is concave, a portion of the image-side surface of the sixth lens close to the optical axis is concave, the focal length of the sixth lens is f6, the focal length of the imaging optical lens is f, the central curvature of the object-side surface of the sixth lens is R11, the central curvature of the image-side surface of the sixth lens is R12, and the thickness of the sixth lens on the optical axis is d11, satisfying the following relational expressions: -3.61≦f6 / f≦-0.99, 0.18≦(R11+R12) / (R11-R12)≦1.24, and 0.02≦d11 / TTL≦0.06.

[0015] Preferably, a portion of the object-side surface of the seventh lens close to the optical axis is a convex surface, a portion of the image-side surface of the seventh lens close to the optical axis is a convex surface, the central curvature of the object-side surface of the seventh lens is R13, the central curvature of the image-side surface of the seventh lens is R14, and the thickness of the seventh lens on the optical axis is d13, satisfying the following relations: -0.98≦(R13+R14) / (R13−R14)≦−0.26, 0.04≦d13 / TTL≦0.21.

[0016] Preferably, the first lens is made of a glass material, and the fourth lens is made of a glass material.

[0017] The present invention provides the following advantages: The imaging optical lens according to the present invention has excellent optical properties, a large aperture, a wide angle, and an ultra-thin profile, and is particularly suitable for use in mobile imaging lens assemblies, web imaging lenses, and vehicle-mounted lenses that are configured with imaging elements such as high-pixel CCDs and CMOSs. [Brief explanation of the drawings]

[0018] In order to more clearly describe the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. However, the drawings in the following description only relate to a part of the embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative efforts.

[0019] [Figure 1] 1 is a schematic diagram showing the structure of an imaging optical lens according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of axial chromatic aberration of the imaging optical lens shown in FIG. [Figure 3] FIG. 2 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 4] 2 is a schematic diagram of field curvature and distortion of the imaging optical lens shown in FIG. 1. [Figure 5] FIG. 4 is a schematic diagram showing the structure of an imaging optical lens according to a second embodiment of the present invention. [Figure 6] FIG. 6 is a schematic diagram of axial chromatic aberration of the imaging optical lens shown in FIG. 5. [Figure 7] FIG. 6 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in FIG. 5. [Figure 8] 6A and 6B are schematic diagrams of field curvature and distortion of the imaging optical lens shown in FIG. 5. [Figure 9] FIG. 10 is a schematic diagram showing the structure of an imaging optical lens according to a third embodiment of the present invention. [Figure 10] FIG. 10 is a schematic diagram of axial chromatic aberration of the imaging optical lens shown in FIG. [Figure 11] FIG. 10 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 12] 10A and 10B are schematic diagrams of field curvature and distortion of the imaging optical lens shown in FIG. [Figure 13] FIG. 10 is a schematic diagram showing the structure of an imaging optical lens according to a fourth embodiment of the present invention. [Figure 14] FIG. 14 is a schematic diagram of axial chromatic aberration of the imaging optical lens shown in FIG. [Figure 15] FIG. 14 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 16] 14A and 14B are schematic diagrams of field curvature and distortion of the imaging optical lens shown in FIG. 13. [Figure 17] FIG. 10 is a schematic diagram showing the structure of an imaging optical lens according to a fifth embodiment of the present invention. [Figure 18] FIG. 18 is a schematic diagram of axial chromatic aberration of the imaging optical lens shown in FIG. [Figure 19] FIG. 18 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 20] 18A and 18B are schematic diagrams of field curvature and distortion of the imaging optical lens shown in FIG. 17. [Figure 21] FIG. 10 is a schematic diagram showing the structure of an imaging optical lens according to a comparative embodiment. [Figure 22] FIG. 22 is a schematic diagram of axial chromatic aberration of the imaging optical lens shown in FIG. 21. [Figure 23] FIG. 22 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in FIG. 21. [Figure 24] 22A and 22B are schematic diagrams of field curvature and distortion of the imaging optical lens shown in FIG. 21. DETAILED DESCRIPTION OF THE INVENTION

[0020] In order to clarify the objectives, technical solutions, and advantages of the present invention, the following detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the embodiments of the present invention to help readers better understand the present invention. However, the technical solutions claimed for the protection of the present invention can be realized without these technical details or various changes and modifications based on the following embodiments.

[0021] Referring to FIGS. 1 to 20, imaging optical lenses 10, 20, 30, 40, and 50 are provided according to the present invention. FIGS. 1, 5, 9, 13, and 17 show imaging optical lenses 10, 20, 30, 40, and 50 according to the present invention. Each imaging optical lens 10, 20, 30, 40, and 50 includes seven lenses in total. Specifically, the imaging optical lenses 10, 20, 30, 40, and 50 are arranged in this order from the object side to the image side: a first lens L1, a second lens L2, a third lens L3, a diaphragm S1, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7. An optical element such as an optical filter GF may be provided between the seventh lens L7 and the image plane Si. The diaphragm S1 may be provided between the fourth lens L4 and the fifth lens L5.

[0022] In this embodiment, the first lens L1 is made of glass, the second lens L2 is made of resin, the third lens L3 is made of resin, the fourth lens L4 is made of glass, the fifth lens L5 is made of resin, the sixth lens L6 is made of resin, and the seventh lens L7 is made of resin. Each lens may be made of other materials.

[0023] The object side and image side surfaces of the first lens L1 and the fourth lens L4 are all spherical, and the object side and image side surfaces of the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are aspherical.

[0024] The focal length of the fifth lens L5 is f5, and the focal length of the sixth lens L6 is f6, and the relationship -6.50≦f5 / f6≦-2.30 is satisfied. By specifying the proportional values of the focal lengths of the fifth lens L5 and the sixth lens L6, which are cemented together so that the above relationship is satisfied, the amount of field curvature of the system can be effectively balanced, and the shift amount of field curvature in the central field of view can be reduced to less than 0.02 mm. Here, the system is an imaging optical lens.

[0025] The distance on the optical axis between the third lens L3 and the fourth lens L4 is d6, and the total optical length of the imaging optical lens is TTL, and the relational expression 0.035≦d6 / TTL≦0.055 is satisfied. In this way, by specifying the proportional value between the distance on the optical axis between the third lens L3 and the fourth lens L4 and the total optical length so that the above relational expression is satisfied, when the third lens L3 and the fourth lens L4 are located near the aperture stop S1, light rays near the aperture stop S1 can transition smoothly, thereby improving the imaging mass.

[0026] The central radius of curvature of the object-side surface of fourth lens L4 is R7, and the central radius of curvature of the image-side surface of fourth lens L4 is R8, satisfying the relational expression: -3.50≦R7 / R8≦-1.80. By specifying the shape of fourth lens L4 so that the above relational expression is satisfied, light rays can transition smoothly, thereby improving the imaging mass.

[0027] When the above-mentioned relational expressions are satisfied, the imaging optical lenses 10, 20, 30, 40, and 50 have excellent optical performance and can satisfy the design requirements for a large aperture, a wide angle of view, and an ultra-thin design. These characteristics of the imaging optical lenses 10, 20, 30, 40, and 50 make them particularly suitable for use in mobile imaging lens assemblies, web imaging lenses, and vehicle-mounted lenses, which are configured with imaging elements such as high-pixel CCDs and CMOSs.

[0028] Based on the above relational expressions and realizable functions, the characteristics of each lens will be described in detail.

[0029] The distance from the seventh lens L7 to the image plane Si is BFL, and the total optical length of the imaging optical lens is TTL, and the relationship 0.15≦BFL / (TTL-BFL)≦0.25 is satisfied. By specifying the relationship between the back focal length and the total optical length, when the imaging optical lens is made compact, assembling the module becomes easier if the back focal length is longer, and on the other hand, assembling the lens group (TTL-BFL) becomes shorter, the structure becomes more compact, the sensitivity of the lens to MTF is reduced, and it is possible to improve yield and reduce costs.

[0030] The focal length of the seventh lens L7 is f7, the focal length of the imaging optical lens is f, and the proportional value between the focal length of the seventh lens L7 and the overall focal length of the imaging optical lens is determined by satisfying the relationship 1.50≦f7 / f≦2.50. By reasonably distributing the power of the system to support light collection, the amount of light passing through can be guaranteed.

[0031] The Abbe number of the fifth lens L5 is v5, and the Abbe number of the sixth lens L6 is v6, and they satisfy the following relationship: 35.00≦v5−v6≦70.00. In this way, by specifying the difference in the Abbe numbers of the two lenses attached so that the above relationship is satisfied, the material attributes can be effectively distributed, and chromatic aberration can be effectively corrected so that the relationship: chromatic aberration |LC|≦7.0 μm is satisfied.

[0032] The refractive index of the first lens L1 is n1, which satisfies the relational expression 1.70≦n1≦2.20. By preferentially using a high refractive index material for the first lens L1 in this way, it is possible to reduce the front end diameter and improve the imaging mass.

[0033] The object side surface of the first lens L1 near the optical axis is a convex surface, and the image side surface of the first lens L1 near the optical axis is a concave surface, and the first lens L1 has negative refractive power. The object side surface and the image side surface of the first lens L1 may have other concave or convex distributions.

[0034] Let f be the focal length of the imaging optical lens, and f be the focal length of the first lens L1, and the relational expression -6.18≦f1 / f≦-1.84 be satisfied. In this way, by specifying the proportional value between the focal length of the first lens L1 and the focal length of the imaging optical lens so that the above relational expression is satisfied, the balance of the amount of field curvature of the system can be effectively corrected. It is also preferable to satisfy -3.86≦f1 / f≦-2.30.

[0035] The central curvature of the object-side surface of the first lens L1 is R1, and the central curvature of the image-side surface of the first lens L1 is R2, and they satisfy the relational expression 0.83≦(R1+R2) / (R1-R2)≦2.99. By rationally specifying the shape of the first lens L1 in this way, the first lens L1 can effectively correct the spherical aberration of the system. It is also preferable that the relation 1.32≦(R1+R2) / (R1-R2)≦2.39 be satisfied.

[0036] The thickness of the first lens L1 on the optical axis is d1, and the total optical length of the imaging optical lens is TTL, which satisfies the relational expression 0.02≦d1 / TTL≦0.11. When this relational expression is satisfied, the imaging optical lens can be made ultra-thin. It is also preferable that the relational expression 0.03≦d1 / TTL≦0.09 is satisfied.

[0037] The object side surface of the second lens L2 near the optical axis is a convex surface, and the image side surface of the second lens L2 near the optical axis is a concave surface, and the second lens L2 has negative refractive power. The object side surface and the image side surface of the second lens L2 may be provided with other concave or convex distributions.

[0038] If the focal length of the imaging optical lens is f and the focal length of the second lens L2 is f2, the aberrations of the system can be corrected by satisfying the relational expression -6.67≦f2 / f≦-1.98 and controlling the negative power of the second lens L2 within a reasonable range. It is preferable to satisfy the relation -4.17≦f2 / f≦-2.48.

[0039] The central curvature of the object-side surface of the second lens L2 is R3, and the central curvature of the image-side surface of the second lens L2 is R4, and they satisfy the relational expression 0.53≦(R3+R4) / (R3-R4)≦1.90. By rationally specifying the shape of the second lens L2 in this way, the second lens L2 can efficiently correct the spherical aberration of the system. It is also preferable that the relation 0.85≦(R3+R4) / (R3-R4)≦1.52 be satisfied.

[0040] The thickness of the second lens L2 on the optical axis is d3, and the total optical length of the imaging optical lens is TTL, which satisfies the relational expression 0.003≦d3 / TTL≦0.06. When this relational expression is satisfied, the imaging optical lens can be made ultra-thin. It is also preferable to satisfy the relation 0.005≦d3 / TTL≦0.05.

[0041] The object side surface of the third lens L3 near the optical axis is concave, and the image side surface of the third lens L3 near the optical axis is convex, and the third lens L3 has positive refractive power. The object side surface and the image side surface of the third lens L3 may have other concave or convex distributions.

[0042] The focal length of the imaging optical lens is f, the focal length of the third lens L3 is f3, and the relationship 2.66≦f3 / f≦8.82 is satisfied. By reasonably distributing the power of the third lens L3, the system can have excellent imaging quality and low sensitivity, and preferably satisfying 4.25≦f3 / f≦7.06.

[0043] The central curvature of the object-side surface of the third lens L3 is R5, the central curvature of the image-side surface of the third lens L3 is R6, and by satisfying the relational expression 1.05≦(R5+R6) / (R5-R6)≦3.65, specifying the shape of the third lens L3 so that this relational expression is satisfied makes it possible to correct axial chromatic aberration as imaging optical lenses become ultra-thin and have a wide angle of view. It is also preferable to satisfy 1.69≦(R5+R6) / (R5-R6)≦2.92.

[0044] The thickness of the third lens L3 on the optical axis is d5, and the total optical length of the imaging optical lens is TTL, satisfying the relational expression 0.09≦d5 / TTL≦0.31. When this relational expression is satisfied, the imaging optical lens can be made ultra-thin. It is also preferable to satisfy the relation 0.15≦d5 / TTL≦0.24.

[0045] The fourth lens L4 has a convex surface on its object side near the optical axis and a convex surface on its image side near the optical axis, and has positive refractive power. The object side and image side surfaces of the fourth lens L4 may have other concave or convex distributions.

[0046] The focal length of the imaging optical lens is f, and the focal length of the fourth lens L4 is f4, and the relationship 1.38≦f4 / f≦4.36 is satisfied. By reasonably distributing the power of the fourth lens L4, the system can have excellent imaging quality and low sensitivity, and it is preferable to satisfy the relationship 2.21≦f4 / f≦3.49.

[0047] The thickness of the fourth lens L4 on the optical axis is d7, and the total optical length of the imaging optical lens is TTL, and the relational expression 0.03≦d7 / TTL≦0.14 is satisfied. When the above relational expression is satisfied, the imaging optical lens can be made ultra-thin. It is also preferable that the relational expression 0.05≦d7 / TTL≦0.11 is satisfied.

[0048] The fifth lens L5 has a convex surface on its object side near the optical axis, a convex surface on its image side near the optical axis, and a positive refractive power. The object side and image side surfaces of the fifth lens L5 may have other concave or convex distributions.

[0049] The focal length of the imaging optical lens is f, and the focal length of the fifth lens L5 is f5. The relationship 1.87≦f5 / f≦17.58 is satisfied. The fifth lens L5 can effectively reduce the ray angle of the imaging optical lens, thereby reducing tolerance sensitivity. It is preferable that the relationship 2.99≦f5 / f≦14.07 is satisfied.

[0050] The shape of the fifth lens L5 can be specified by satisfying the relational expression -0.25≦(R9+R10) / (R9-R10)≦0.43, where R9 is the central curvature of the object-side surface of the fifth lens L5 and R10 is the central curvature of the image-forming side surface of the fifth lens L5. When this relational expression is satisfied, field curvature and distortion can be corrected. It is preferable to satisfy the relational expression -0.15≦(R9+R10) / (R9-R10)≦0.34.

[0051] The thickness of the fifth lens L5 on the optical axis is d9, and the total optical length of the imaging optical lens is TTL, and the relational expression 0.04≦d9 / TTL≦0.15 is satisfied. When the above relational expression is satisfied, the imaging optical lens can be made ultra-thin. It is also preferable that the relational expression 0.07≦d9 / TTL≦0.12 is satisfied.

[0052] The sixth lens L6 has a concave surface on its object side near the optical axis, a concave surface on its image side near the optical axis, and a negative refractive power. The object side and image side surfaces of the sixth lens L6 may have other concave or convex distributions.

[0053] The focal length of the imaging optical lens L6 is f, and the focal length of the sixth lens L6 is f6, and the relationship -3.61≦f6 / f≦-0.99 is satisfied. By reasonably distributing the power of the sixth lens L6, the system can have excellent imaging quality and low sensitivity, and it is preferable to satisfy the relationship -2.26≦f6 / f≦-1.24.

[0054] The shape of the sixth lens L6 can be specified by defining the central curvature of the object-side surface of the sixth lens L6 as R11 and the central curvature of the image-side surface of the sixth lens L6 as R12, and satisfying the relational expression 0.18≦(R11+R12) / (R11-R12)≦1.24. When this relational expression is satisfied, chromatic aberrations at off-axis angles of view can be effectively corrected as imaging optical lenses become ultra-thin and have wide angles of view. It is also preferable to satisfy 0.28≦(R11+R12) / (R11-R12)≦1.00.

[0055] The thickness of the sixth lens L6 on the optical axis is d11, and the total optical length of the imaging optical lens is TTL, and the relational expression 0.02≦d11 / TTL≦0.06 is satisfied. When the above relational expression is satisfied, the imaging optical lens can be made ultra-thin. It is also preferable that the relational expression 0.04≦d11 / TTL≦0.07 is satisfied.

[0056] The seventh lens L7 has a convex surface on the object side close to the optical axis, a convex surface on the image side close to the optical axis, and a positive refractive power. The object side and image side surfaces of the seventh lens L7 may have other concave or convex distributions.

[0057] The shape of the seventh lens L7 can be specified by defining the central curvature of the object-side surface of the seventh lens L7 as R13 and the central curvature of the image-side surface of the seventh lens L7 as R14, and satisfying the relational expression -0.98≦(R13+R14) / (R13-R14)≦-0.26. When this relational expression is satisfied, chromatic aberrations at off-axis angles of view can be effectively corrected as imaging optical lenses become ultra-thin and have wide angles of view. It is also preferable to satisfy the relation -0.61≦(R13+R14) / (R13-R14)≦-0.32.

[0058] The thickness of the seventh lens L7 on the optical axis is d13, and the total optical length of the imaging optical lens is TTL, and the relational expression 0.04≦d13 / TTL≦0.21 is satisfied. When this relational expression is satisfied, the imaging optical lens can be made ultra-thin. It is also preferable that the relational expression 0.06≦d13 / TTL≦0.17 is satisfied.

[0059] The image height of the imaging optical lens is IH, the total optical length of the imaging optical lens is TTL, and by satisfying the relation TTL / IH≦6.68, the imaging optical lens can be made ultra-thin. It is preferable to satisfy TTL / IH≦6.49.

[0060] The imaging optical lens has a field of view FOV of 176.40° or more, which makes it possible to realize a wide field of view for the imaging optical lens. Preferably, the imaging optical lens has a field of view FOV of 180.00° or more.

[0061] Since the aperture value FNO (F-number) of the imaging optical lens is 1.95 or less, a large aperture can be achieved for the imaging optical lens, and the imaging performance of the imaging optical lens can be improved. It is preferable that the aperture value FNO of the imaging optical lens is 1.90 or less.

[0062] The imaging optical lens according to the present invention will be described below using examples. The symbols used in each example are as follows: The focal length, axial distance, central radius of curvature, and axial thickness are all in mm.

[0063] TTL is the total optical length (the distance on the optical axis from the object side of the first lens L1 to the image plane Si) and is expressed in mm.

[0064] The aperture value FNO refers to the ratio of the effective focal length to the effective aperture of an imaging optical lens.

[0065] Preferably, the object side and / or image side of the lens may further be provided with curvature points and / or stationary points to meet the demand for high quality imaging, and specific embodiments are described below.

[0066] Below, the present invention will be described in detail using five embodiments, and one comparative embodiment will be presented to explain that the technical effects of the present invention cannot be obtained if the above-mentioned relationship is not satisfied.

[0067] (First embodiment) Tables 1 and 2 show design data for the imaging optical lens 10 according to the first embodiment of the present invention.

[0068] [Table 1]

[0069] The meaning of each symbol is as follows: S1: Aperture R: Radius of curvature at the center of the optical surface R1: Radius of curvature of the center of the object side of the first lens L1 R2: Radius of central curvature of the image-forming side of the first lens L1 R3: Radius of curvature of the center of the object side of the second lens L2 R4: Radius of central curvature of the image-forming side of the second lens L2 R5: Radius of curvature of the center of the object side of the third lens L3 R6: Radius of central curvature of the image-forming side of the third lens L3 R7: Radius of curvature of the center of the object side of the fourth lens L4 R8: Radius of central curvature of the image-forming side of the fourth lens L4 R9: Radius of curvature of the center of the object side of the fifth lens L5 R10: Radius of central curvature of the imaging side of the fifth lens L5 R11: Radius of curvature of the center of the object side of the sixth lens L6 R12: Radius of central curvature of the image-forming side of the sixth lens L6 R13: Radius of curvature of the center of the object side of the seventh lens L7 R14: Radius of central curvature of the image-forming side of the seventh lens L7 R15: Radius of curvature of the center of the object side of the optical filter GF R16: Radius of central curvature of the imaging side of the optical filter GF d: Lens thickness on the optical axis, distance between lenses on the optical axis d0: Distance on the optical axis from the aperture stop S1 to the object side of the first lens L1 d1: thickness of the first lens L1 on the optical axis d2: the distance on the optical axis from the image-forming side surface of the first lens L1 to the object-side surface of the second lens L2 d3: Thickness of the second lens L2 on the optical axis d4: The distance on the optical axis from the image-forming side of the second lens L2 to the object-side of the third lens L3 d5: Thickness of the third lens L3 on the optical axis d6: the distance on the optical axis from the image-forming side surface of the third lens L3 to the object-side surface of the fourth lens L4 d7: Thickness of the fourth lens L4 on the optical axis d8: the distance on the optical axis from the image-forming side surface of the fourth lens L4 to the object-side surface of the fifth lens L5 d9: Thickness of the fifth lens element L5 on the optical axis d10: the distance on the optical axis from the image-forming side surface of the fifth lens L5 to the object-side surface of the sixth lens L6 d11: Thickness of the sixth lens element L6 on the optical axis d12: the distance on the optical axis from the image-forming side surface of the sixth lens L6 to the object-side surface of the seventh lens L7 d13: Axial thickness of the seventh lens element L7 d14: The distance on the optical axis from the image-forming side surface of the seventh lens L7 to the object-side surface of the optical filter GF d15: Thickness of the optical filter GF on the optical axis d16: Distance on the optical axis from the imaging side of the optical filter GF to the imaging surface Si nd: Refractive index of the d-line (d-line is green light with a wavelength of 550 nm). nd1: refractive index of the first lens L1 at the d line nd2: refractive index of the d line of the second lens L2 nd3: refractive index of the d line of the third lens L3 nd4: Refractive index of the d line of the fourth lens L4 nd5: refractive index of the d line of the fifth lens L5 nd6: Refractive index of the d line of the sixth lens L6 nd7: Refractive index of the d line of the seventh lens L7 ndg: refractive index of the d line of the optical filter GF vd: Abbe number v1: Abbe number of the first lens L1 v2: Abbe number of the second lens L2 v3: Abbe number of the third lens element L3 v4: Abbe number of the fourth lens element L4 v5: Abbe number of the fifth lens element L5 v6: Abbe number of the sixth lens element L6 v7: Abbe number of the seventh lens element L7 vg: Abbe number of the optical filter GF

[0070] Table 2 shows the aspheric surface data of each lens in the imaging optical lens 10 according to the first embodiment of the present invention.

[0071] [Table 2]

[0072] For convenience, the aspherical surface of each lens surface is assumed to be aspherical as shown in the following formula (1). However, the present invention is not limited to the form of the aspherical polynomial expressed by formula (1). z=(cr 2 ) / {1+[1-(k+1)(c 2 r 2 )] 1 / 2}+A4r 4 +A6r 6 +A8r 8 +A10r 10 +A12r 12 +A14r 14 +A16r 16 +A18r 18 +A20r 20 (1)

[0073] Here, k is a conic coefficient, A4, A6, A8, A10, A12, A14, A16, A18, and A20 are aspheric coefficients, c is the curvature of the central location of the optical surface, r is the perpendicular distance between a point on the aspheric curve and the optical axis, and z is the aspheric depth (the perpendicular distance between a point on the aspheric surface that is a distance r from the optical axis and a tangent plane that is in contact with the vertex on the aspheric optical axis).

[0074] 2 and 3 are schematic diagrams of the axial chromatic aberration and lateral chromatic aberration of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm after passing through the imaging optical lens 10 according to the first embodiment. Fig. 4 is a schematic diagram of the field curvature and distortion aberration of light with a wavelength of 555 nm after passing through the imaging optical lens 10 according to the first embodiment. In Fig. 4, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the meridional direction.

[0075] In this embodiment, the imaging optical lens 10 has an effective aperture ENPD of 1.544 mm, a full-field image height IH of 4.320 mm, and a diagonal angle of view FOV of 180.00°. The imaging optical lens 10 satisfies the design requirements for a large aperture, a wide angle, and an ultra-thin design, and has excellent optical properties with sufficient correction of chromatic aberrations on and off the optical axis.

[0076] (Second embodiment) The meanings of the symbols in the second embodiment are the same as those in the first embodiment.

[0077] FIG. 5 shows an imaging optical lens 20 according to a second embodiment of the present invention.

[0078] Tables 3 and 4 show design data for the imaging optical lens 20 according to the second embodiment of the present invention.

[0079] [Table 3]

[0080] Table 6 shows the aspheric surface data of each lens in the imaging optical lens 20 according to the second embodiment of the present invention.

[0081] [Table 4]

[0082] Figures 6 and 7 are schematic diagrams of the axial chromatic aberration and lateral chromatic aberration of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm after passing through the imaging optical lens 20 according to the second embodiment. Figure 8 is a schematic diagram of the field curvature and distortion aberration of light with a wavelength of 555 nm after passing through the imaging optical lens 20 according to the second embodiment. In Figure 8, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the meridional direction.

[0083] In this embodiment, the imaging optical lens 20 has an effective aperture ENPD of 1.544 mm, a full-field image height IH of 4.410 mm, and a diagonal angle of view FOV of 180.07°. The imaging optical lens 20 satisfies the design requirements for a large aperture, a wide angle, and an ultra-thin design, has sufficient correction for chromatic aberrations on and off the optical axis, and has excellent optical properties.

[0084] (Third embodiment) The meanings of the symbols in the third embodiment are the same as those in the first embodiment.

[0085] FIG. 9 shows an imaging optical lens 30 according to a third embodiment of the present invention.

[0086] Tables 5 and 6 show design data for the imaging optical lens 30 according to the third embodiment of the present invention.

[0087] [Table 5]

[0088] Table 6 shows the aspheric surface data of each lens in the imaging optical lens 30 according to the third embodiment of the present invention.

[0089] [Table 6]

[0090] 10 and 11 are schematic diagrams of the axial chromatic aberration and lateral chromatic aberration of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm after passing through the imaging optical lens 30 according to the third embodiment. Fig. 12 is a schematic diagram of the field curvature and distortion aberration of light with a wavelength of 555 nm after passing through the imaging optical lens 30 according to the third embodiment. In Fig. 12, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the meridional direction.

[0091] In this embodiment, the imaging optical lens 30 has an effective aperture ENPD of 1.544 mm, a full-field image height IH of 4.512 mm, and a diagonal angle of view FOV of 180.00°. The imaging optical lens 30 satisfies the design requirements for a large aperture, a wide angle, and an ultra-thin design, has sufficient correction for chromatic aberrations on and off the optical axis, and has excellent optical characteristics.

[0092] (Fourth embodiment) The meanings of the symbols in the fourth embodiment are the same as those in the first embodiment.

[0093] FIG. 13 shows an imaging optical lens 40 according to a fourth embodiment of the present invention.

[0094] Tables 7 and 8 show design data for the imaging optical lens 40 according to the fourth embodiment of the present invention.

[0095] [Table 7]

[0096] Table 8 shows the aspheric surface data of each lens in the imaging optical lens 40 according to the fourth embodiment of the present invention.

[0097] [Table 8]

[0098] 14 and 15 are schematic diagrams of the axial chromatic aberration and lateral chromatic aberration of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm after passing through the imaging optical lens 40 according to the fourth embodiment. Fig. 16 is a schematic diagram of the field curvature and distortion aberration of light with a wavelength of 555 nm after passing through the imaging optical lens 40 according to the fourth embodiment. The field curvature S in Fig. 16 is the field curvature in the sagittal direction, and T is the field curvature in the meridional direction.

[0099] In this embodiment, the imaging optical lens 40 has an effective aperture ENPD of 1.544 mm, a full-field image height IH of 4.349 mm, and a diagonal angle of view FOV of 180.00°. The imaging optical lens 40 satisfies the design requirements for a large aperture, a wide angle, and an ultra-thin design, has sufficient correction for chromatic aberrations on and off the optical axis, and has excellent optical characteristics.

[0100] (Fifth embodiment) The meanings of the symbols in the fifth embodiment are the same as those in the first embodiment.

[0101] FIG. 17 shows an imaging optical lens 50 according to a fifth embodiment of the present invention.

[0102] Tables 9 and 10 show design data for the imaging optical lens 50 according to the fifth embodiment of the present invention.

[0103] [Table 9]

[0104] Table 10 shows the aspheric data of each lens in the imaging optical lens 50 according to the fifth embodiment of the present invention.

[0105] [Table 10]

[0106] 18 and 19 are schematic diagrams of the axial chromatic aberration and lateral chromatic aberration of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm after passing through the imaging optical lens 50 according to the fifth embodiment. Fig. 20 is a schematic diagram of the field curvature and distortion aberration of light with a wavelength of 555 nm after passing through the imaging optical lens 50 according to the fifth embodiment. In Fig. 20, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the meridional direction.

[0107] In this embodiment, the imaging optical lens 50 has an effective aperture ENPD of 1.544 mm, a full field-of-view image height IH of 4.363 mm, and a diagonal angle of view FOV of 180.00°. The imaging optical lens 50 satisfies the design requirements for a large aperture, a wide angle, and an ultra-thin design, has sufficient correction for chromatic aberrations on and off the optical axis, and has excellent optical characteristics.

[0108] Table 13, which will be described later, shows values corresponding to the parameters specified by various numerical values and conditional expressions according to the first, second, third, fourth and fifth embodiments.

[0109] (Comparative embodiment) The symbols in the comparative embodiment have the same meanings as those in the first embodiment.

[0110] FIG. 21 shows an imaging optical lens 60 according to a comparative embodiment.

[0111] Tables 11 and 12 show design data for the imaging optical lens 60 according to the comparative embodiment.

[0112] [Table 11]

[0113] Table 12 shows the aspheric data of each lens in the imaging optical lens 60 according to the comparative embodiment.

[0114] [Table 12]

[0115] 22 and 23 are schematic diagrams of axial chromatic aberration and lateral chromatic aberration of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm after passing through the imaging optical lens 60 according to the comparative embodiment. Fig. 24 is a schematic diagram of field curvature and distortion aberration of light with a wavelength of 555 nm after passing through the imaging optical lens 60 according to the comparative embodiment. In Fig. 24, field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the meridional direction.

[0116] Table 13 below lists values corresponding to each conditional expression of the comparative embodiment according to the above conditional expressions. Clearly, the imaging optical lens 60 according to the comparative embodiment does not satisfy the above conditional expression -6.50≦f5 / f6≦−2.30.

[0117] In the comparative embodiment, the imaging optical lens 60 has an effective aperture ENPD of 1.544 mm, a full field of view image height IH of 4.495 mm, and a diagonal field of view FOV of 180.00°. The imaging optical lens 60 does not meet the design requirements for a large aperture, a wide angle, and an ultra-thin design.

[0118] [Table 13]

[0119] Those skilled in the art will understand that the above embodiments are specific embodiments for realizing the present invention. In practical applications, various changes may be made to the form and details without departing from the spirit and scope of the present invention.

Claims

1. 1. An imaging optical lens, comprising: The optical lens comprises a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, a fourth lens having positive refractive power, a fifth lens having positive refractive power, a sixth lens having negative refractive power, and a seventh lens having positive refractive power, which are arranged in this order from the object side to the image side, The focal length of the fifth lens is f5, The sixth lens has a focal length of f6. The distance on the optical axis between the third lens and the fourth lens is d6, the total optical length of the imaging optical lens is TTL, the central radius of curvature of the object-side surface of the fourth lens is R7; The central radius of curvature of the image-forming side surface of the fourth lens is R8, -6.50≦f5 / f6≦-2.30 0.035≦d6 / TTL≦0.055 -3.50≦R7 / R8≦-1.80 Satisfying the above relation, An imaging optical lens characterized by:

2. the distance from the seventh lens to the image plane is BFL, 0.15≦BFL / (TTL-BFL)≦0.25 Satisfying the above relation, 2. The imaging optical lens according to claim 1.

3. The seventh lens has a focal length of f7, the focal length of the imaging optical lens is f; 1.50≦f7 / f≦2.50 Satisfying the above relation, 2. The imaging optical lens according to claim 1.

4. the Abbe number of the fifth lens is v5, the Abbe number of the sixth lens is v6; 35.00≦v5−v6≦70.00 Satisfying the above relation, 2. The imaging optical lens according to claim 1.

5. The refractive index of the first lens is n1, 1.70≦n1≦2.20 Satisfying the above relation, 2. The imaging optical lens according to claim 1.

6. a portion of the object side surface of the first lens that is close to the optical axis is a convex surface, a portion of the imaging side surface of the first lens that is close to the optical axis is concave; The focal length of the first lens is f1, the focal length of the imaging optical lens is f; the central curvature of the object side surface of the first lens is R1; the central curvature of the image-forming side surface of the first lens is R2; The thickness of the first lens on the optical axis is d1, −6.18≦f1 / f≦−1.84 0.83≦(R1+R2) / (R1-R2)≦2.99 0.02≦d1 / TTL≦0.11 Satisfying the above relation, 2. The imaging optical lens according to claim 1.

7. a portion of the object side surface of the second lens that is close to the optical axis is a convex surface, a portion of the imaging side surface of the second lens that is close to the optical axis is concave; The focal length of the second lens is f2, the focal length of the imaging optical lens is f; the central curvature of the object side surface of the second lens is R3; the central curvature of the image-forming side surface of the second lens is R4; The thickness of the second lens on the optical axis is d3, −6.67≦f2 / f≦−1.98 0.53≦(R3+R4) / (R3-R4)≦1.90 0.003≦d3 / TTL≦0.06 Satisfying the above relation, 2. The imaging optical lens according to claim 1.

8. a portion of the object side surface of the third lens that is close to the optical axis is concave, a portion of the imaging side surface of the third lens that is close to the optical axis is a convex surface, The focal length of the third lens is f3, the focal length of the imaging optical lens is f; the central curvature of the object side surface of the third lens is R5; The central curvature of the image-forming side surface of the third lens is R6, The thickness of the third lens on the optical axis is d5, 2.66≦f3 / f≦8.82 1.05≦(R5+R6) / (R5-R6)≦3.65 0.09≦d5 / TTL≦0.31 Satisfying the above relation, 2. The imaging optical lens according to claim 1.

9. a portion of the object side surface of the fourth lens that is close to the optical axis is a convex surface, a portion of the image-forming side surface of the fourth lens that is close to the optical axis is a convex surface, The focal length of the fourth lens is f4, the focal length of the imaging optical lens is f; The thickness of the fourth lens on the optical axis is d7, 1.38≦f4 / f≦4.36 0.03≦d7 / TTL≦0.14 Satisfying the above relation, 2. The imaging optical lens according to claim 1.

10. a portion of the object side surface of the fifth lens that is close to the optical axis is a convex surface, a portion of the imaging side surface of the fifth lens that is close to the optical axis is a convex surface, The focal length of the fifth lens is f5, the focal length of the imaging optical lens is f; the central curvature of the object side surface of the fifth lens is R9, the central curvature of the image-forming side surface of the fifth lens is R10; The fifth lens has an axial thickness of d9, 1.87≦f5 / f≦17.58 -0.25≦(R9+R10) / (R9-R10)≦0.43 0.04≦d9 / TTL≦0.15 Satisfying the above relation, 2. The imaging optical lens according to claim 1.

11. a portion of the sixth lens on the object side close to the optical axis is concave, a portion of the imaging side surface of the sixth lens that is close to the optical axis is concave, The sixth lens has a focal length of f6. the focal length of the imaging optical lens is f; the central curvature of the object side surface of the sixth lens is R11, The central curvature of the image-forming side surface of the sixth lens is R12, The sixth lens has an axial thickness of d11, −3.61≦f6 / f≦−0.99 0.18≦(R11+R12) / (R11-R12)≦1.24 0.02≦d11 / TTL≦0.06 Satisfying the above relation, 2. The imaging optical lens according to claim 1.

12. a portion of the seventh lens on the object side close to the optical axis is a convex surface, a portion of the seventh lens on the imaging side close to the optical axis is a convex surface, the central curvature of the object side surface of the seventh lens is R13, The central curvature of the image-forming side surface of the seventh lens is R14, The seventh lens has an axial thickness of d13, -0.98≦(R13+R14) / (R13-R14)≦-0.26 0.04≦d13 / TTL≦0.21 Satisfying the above relation, 2. The imaging optical lens according to claim 1.

13. The first lens is made of a glass material, and the fourth lens is made of a glass material.

2. The imaging optical lens according to claim 1.

Images