Imaging Optical Lens

Abstract

The present invention relates to the field of optical lenses, and provides an imaging optical lens. [Solution] The imaging optical lens is composed of, in order from the object side to the image side, a first lens having positive refractive power, a second lens having negative refractive power, a third lens having negative refractive power, a fourth lens having refractive power, a fifth lens having positive refractive power, and a sixth lens having negative refractive power, and satisfies conditional expressions 0.10≦d8 / TTL≦0.20, -5.00≦R9 / R10≦-0.80, and 0.70≦f2 / f3≦1.00 when a focal length of the second lens is f2, a focal length of the third lens is f3, an axial distance from the image side surface of the fourth lens to the object side surface of the fifth lens is d8, a central radius of curvature of the object side surface of the fifth lens is R9, a central radius of curvature of the image side surface of the fifth lens is R10, and an optical length of the imaging optical lens is TTL.

Description

[Technical field]

[0001] The present invention relates to the field of optical lenses, and more particularly to imaging optical lenses that are applied to mobile terminal devices such as smartphones and digital cameras, and imaging devices such as monitors, PC lenses, in-vehicle lenses, and drones. [Background technology]

[0002] In recent years, with the rise of various smart devices, the demand for miniaturized imaging optical lenses is increasing. In addition to the pixel size of the photosensitive element being reduced, the current electronic products are in the trend of developing with high functionality and a lightweight, portable appearance. Therefore, miniaturized imaging optical lenses with good imaging quality have become the mainstream in the current market. In order to obtain good imaging quality, a multi-lens structure is often adopted. In addition, with the development of technology and the increasing diversification needs of users, the pixel area of ​​the photosensitive element is shrinking and the system requirements for imaging quality are increasing, so a six-lens structure is gradually appearing in the lens design. There is a strong demand for large-diameter, ultra-thin imaging optical lenses with good optical performance. Summary of the Invention [Problem to be solved by the invention]

[0003] In view of the above problems, an object of the present invention is to provide an imaging optical lens that has good optical performance and satisfies design requirements for a large diameter and an extremely thin lens. [Means for solving the problem]

[0004] In order to solve the above technical problems, an embodiment of the present invention provides an imaging optical lens, which is composed of, in order from the object side to the image side, a first lens having positive refractive power, a second lens having negative refractive power, a third lens having negative refractive power, a fourth lens having refractive power, a fifth lens having positive refractive power, and a sixth lens having negative refractive power, and satisfies the following conditional expressions (1) to (3) when the focal length of the second lens is f2, the focal length of the third lens is f3, the axial distance from the image side surface of the fourth lens to the object side surface of the fifth lens is d8, the central radius of curvature of the object side surface of the fifth lens is R9, the central radius of curvature of the image side surface of the fifth lens is R10, and the optical length of the imaging optical lens is TTL. 0.10≦d8 / TTL≦0.20 (1) -5.00≦R9 / R10≦-0.80 (2) 0.70≦f2 / f3≦1.00 (3)

[0005] Preferably, when the central radius of curvature of the object side surface of the sixth lens is R11 and the central radius of curvature of the image side surface of the sixth lens is R12, the following conditional formula (4) is satisfied. 0.16≦R11 / R12≦0.64 (4)

[0006] Preferably, when the focal length of the imaging optical lens is f and the focal length of the first lens is f1, the following conditional expression (5) is satisfied. 0.40≦f1 / f≦0.50 (5)

[0007] Preferably, when the axial distance from the image side surface of the third lens to the object side surface of the fourth lens is d6 and the axial thickness of the fourth lens is d7, the following conditional expression (6) is satisfied. 2.00≦d6 / d7≦4.00 (6)

[0008] Preferably, the object side surface of the first lens is a convex surface paraxially, the image side surface of the first lens is a convex surface paraxially, and when a central radius of curvature of the object side surface of the first lens is R1, a central radius of curvature of the image side surface of the first lens is R2, and an axial thickness of the first lens is d1, the following conditional expressions (7) to (8) are satisfied. -1.25≦(R1+R2) / (R1-R2)≦-0.32 (7) 0.10≦d1 / TTL≦0.34 (8)

[0009] Preferably, the object side surface of the second lens is a paraxially concave surface, the image side surface of the second lens is a paraxially concave surface, and when a focal length of the imaging optical lens is f, a central radius of curvature of the object side surface of the second lens is R3, a central radius of curvature of the image side surface of the second lens is R4, and an axial thickness of the second lens is d3, the following conditional expressions (9) to (11) are satisfied. -2.25≦f2 / f≦-0.61 (9) 0.38≦(R3+R4) / (R3-R4)≦1.37 (10) 0.01≦d3 / TTL≦0.06 (11)

[0010] Preferably, the object side surface of the third lens is a convex surface paraxially, the image side surface of the third lens is a concave surface paraxially, and when a focal length of the imaging optical lens is f, a central radius of curvature of the object side surface of the third lens is R5, a central radius of curvature of the image side surface of the third lens is R6, and an axial thickness of the third lens is d5, the following conditional expressions (12) to (14) are satisfied. -3.15≦f3 / f≦-0.62 (12) 1.04≦(R5+R6) / (R5-R6)≦4.75 (13) 0.02≦d5 / TTL≦0.07 (14)

[0011] Preferably, when a focal length of the imaging optical lens is f, a focal length of the fourth lens is f4, a central radius of curvature of the object side surface of the fourth lens is R7, a central radius of curvature of the image side surface of the fourth lens is R8, and an axial thickness of the fourth lens is d7, the following conditional expressions (15) to (17) are satisfied. -34.78≦f4 / f≦28.49 (15) -5.49≦(R7+R8) / (R7-R8)≦1.62 (16) 0.02≦d7 / TTL≦0.07 (17)

[0012] Preferably, the object side surface of the fifth lens is a paraxial convex surface, the image side surface of the fifth lens is a paraxial convex surface, and when the focal length of the imaging optical lens is f, the focal length of the fifth lens is f5, and the axial thickness of the fifth lens is d9, the following conditional expressions (18) to (20) are satisfied. 0.95≦f5 / f≦3.59 (18) -0.22≦(R9+R10) / (R9-R10)≦1.00 (19) 0.04≦d9 / TTL≦0.15 (20)

[0013] Preferably, the object side surface of the sixth lens is a concave surface paraxially, and the image side surface of the sixth lens is a convex surface paraxially, and when the focal length of the imaging optical lens is f, the focal length of the sixth lens is f6, the central radius of curvature of the object side surface of the sixth lens is R11, the central radius of curvature of the image side surface of the sixth lens is R12, and the axial thickness of the sixth lens is d11, the following conditional expressions (21) to (23) are satisfied. -4.17≦f6 / f≦-0.60 (21) -9.09≦(R11+R12) / (R11-R12)≦-0.92 (22) 0.02≦d11 / TTL≦0.15 (23) Effect of the Invention

[0014] The imaging optical lens according to the present invention has excellent optical properties and is characterized by a large aperture and extremely thin thickness, and can be applied to imaging lens units of mobile phones and web imaging lenses that are configured with imaging elements such as high-pixel CCD and CMOS.

[0015] In order to more clearly explain the technical solutions of the embodiments of the present invention, the following briefly introduces drawings required for the embodiments. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can further obtain other drawings based on these drawings without any creative work. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic diagram showing a configuration of an imaging optical lens according to a first embodiment of the present invention. [Diagram 2] 2 is a schematic diagram showing axial chromatic aberration of the imaging optical lens shown in FIG. [Diagram 3] 2 is a schematic diagram showing chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 4] 2 is a schematic diagram showing the field curvature and distortion of the imaging optical lens shown in FIG. [Diagram 5] FIG. 4 is a schematic diagram showing the configuration of an imaging optical lens according to a second embodiment of the present invention. [Figure 6] 6 is a schematic diagram showing the longitudinal chromatic aberration of the imaging optical lens shown in FIG. 5. [Figure 7] 6 is a schematic diagram showing chromatic aberration of magnification of the imaging optical lens shown in FIG. 5. [Figure 8] 6 is a schematic diagram showing the field curvature and distortion of the imaging optical lens shown in FIG. 5. [Figure 9] FIG. 11 is a schematic diagram showing the configuration of an imaging optical lens according to a third embodiment of the present invention. [Figure 10] 10 is a schematic diagram showing the longitudinal chromatic aberration of the imaging optical lens shown in FIG. [Figure 11] 10 is a schematic diagram showing chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 12]10A and 10B are schematic diagrams showing the field curvature and distortion of the imaging optical lens shown in FIG. [Figure 13] FIG. 11 is a schematic diagram showing the configuration of an imaging optical lens according to a fourth embodiment of the present invention. [Figure 14] 14 is a schematic diagram showing the longitudinal chromatic aberration of the imaging optical lens shown in FIG. 13. [Figure 15] 14 is a schematic diagram showing chromatic aberration of magnification of the imaging optical lens shown in FIG. 13. [Figure 16] 14 is a schematic diagram showing the field curvature and distortion of the imaging optical lens shown in FIG. 13. [Figure 17] FIG. 13 is a schematic diagram showing the configuration of an imaging optical lens according to a fifth embodiment of the present invention. [Figure 18] 18 is a schematic diagram showing the longitudinal chromatic aberration of the imaging optical lens shown in FIG. 17. [Figure 19] 18 is a schematic diagram showing chromatic aberration of magnification of the imaging optical lens shown in FIG. 17. [Figure 20] 18A to 18C are schematic diagrams showing the field curvature and distortion of the imaging optical lens shown in FIG. 17. [Figure 21] FIG. 13 is a schematic diagram showing a configuration of an imaging optical lens according to a comparative embodiment. [Figure 22] 22 is a schematic diagram showing the longitudinal chromatic aberration of the imaging optical lens shown in FIG. 21. [Figure 23] 22 is a schematic diagram showing chromatic aberration of magnification of the imaging optical lens shown in FIG. 21. [Figure 24] 22A to 22C are schematic diagrams showing the field curvature and distortion of the imaging optical lens shown in FIG. 21. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] In order to make the objectives, solutions and advantages of the present invention clearer, the following describes in detail the embodiments of the present invention with reference to the drawings. It can be understood by those skilled in the art that many technical details are described in the embodiments of the present invention to better understand the present invention. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solution claimed by the present invention can be realized.

[0018] (First embodiment) As shown in the drawings, the present invention provides an imaging optical lens 10. FIG. 1 shows the imaging optical lens 10 according to a first embodiment of the present invention, and the imaging optical lens 10 includes a total of six lenses. Specifically, the imaging optical lens 10 includes, in order from the object side to the image side, a first lens L1, a diaphragm S1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6. An optical element such as an optical filter GF may be provided between the sixth lens L6 and an image plane Si.

[0019] In this embodiment, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all made of plastic material. In other alternative embodiments, each lens may be made of other materials.

[0020] In this embodiment, when the axial distance from the image-side surface of the fourth lens L4 to the object-side surface of the fifth lens L5 is d8 and the optical length of the imaging optical lens 10 is TTL, the conditional formula 0.10≦d8 / TTL≦0.20 is satisfied, the ratio of the air space and the optical length between the fourth lens L4 and the fifth lens L5 is specified, and by rationally allocating the air space within the range of this conditional formula, it is advantageous for achieving telephoto imaging.

[0021] In this embodiment, when the central radius of curvature of the object side surface of the fifth lens L5 is R9 and the central radius of curvature of the image side surface of the fifth lens L5 is R10, the conditional formula -5.00≦R9 / R10≦-0.80 is satisfied, which specifies the shape of the fifth lens L5. Within the range of this conditional formula, the degree of deflection of light passing through the lens can be mitigated, and chromatic aberration is effectively corrected to be |LC|≦3.0 μm.

[0022] In this embodiment, when the focal length of the second lens L2 is f2 and the focal length of the third lens L3 is f3, the conditional formula 0.70≦f2 / f3≦1.00 is satisfied, the ratio of the focal lengths of the second lens L2 and the third lens L3 is specified, and the optical focal lengths of the system are reasonably allocated within the range of the conditional formula, so that the system has excellent imaging quality and low sensitivity.

[0023] In this embodiment, when the central radius of curvature of the object side surface of the sixth lens L6 is R11 and the central radius of curvature of the image side surface of the sixth lens L6 is R12, the conditional formula 0.16≦R11 / R12≦0.64 is satisfied, which defines the shape of the sixth lens L6 and contributes to correcting the astigmatism and distortion of the imaging optical lens within the range of the conditional formula, so that the distortion aberration |Distortion|≦2%, thereby reducing the possibility of vignetting.

[0024] In this embodiment, when the focal length of the imaging optical lens 10 is f and the focal length of the first lens L1 is f1, the conditional formula 0.40≦f1 / f≦0.50 is satisfied, the ratio of the focal lengths of the first lens L1 and the system is specified, and the optical focal length of the system is reasonably allocated within the range of the conditional formula, thereby contributing to the incidence of light and ensuring the amount of passing light.

[0025] In this embodiment, when the axial distance from the image side surface of the third lens L3 to the object side surface of the fourth lens L4 is d6 and the axial thickness of the fourth lens L4 is d7, the conditional formula 2.00≦d6 / d7≦4.00 is satisfied, which specifies the ratio of the air space between the third lens L3 and the fourth lens L4 to the axial thickness of the fourth lens L4 and is advantageous for shortening the overall length of the optical system within the range of the conditional formula.

[0026] In this embodiment, the object side surface of the first lens L1 is a paraxially convex surface, the image side surface of the first lens L1 is a paraxially convex surface, and the first lens L1 has a positive refractive power. In other optional embodiments, the object side surface and the image side surface of the first lens L1 may be arranged in other concave-convex distribution situations.

[0027] When the radius of curvature of the object side surface of the first lens L1 is R1 and the radius of curvature of the image side surface of the first lens L1 is R2, the conditional expression -1.25≦(R1+R2) / (R1-R2)≦-0.32 is satisfied, and the shape of the first lens L1 is reasonably controlled, so that the first lens L1 can effectively correct the system spherical aberration. Preferably, the conditional expression -0.78≦(R1+R2) / (R1-R2)≦-0.40 is satisfied.

[0028] When the axial thickness of the first lens L1 is d1 and the optical length of the imaging optical lens 10 is TTL, the conditional expression 0.10≦d1 / TTL≦0.34 is satisfied, which is advantageous for realizing compactness within the range of the conditional expression. Preferably, the conditional expression 0.17≦d1 / TTL≦0.27 is satisfied.

[0029] In this embodiment, the object side surface of the second lens L2 is paraxially concave, and the image side surface of the second lens L2 is paraxially concave, and the second lens L2 has negative refractive power. In other alternative embodiments, the object side surface and the image side surface of the second lens L2 may be arranged in other concave-convex distribution situations.

[0030] When the focal length of the imaging optical lens 10 is f and the focal length of the second lens L2 is f2, satisfying the conditional expression -2.25≦f2 / f≦-0.61 and controlling the negative power of the second lens L2 within a reasonable range is advantageous for correcting aberrations of the optical system. Preferably, the conditional expression -1.41≦f2 / f≦-0.76 is satisfied.

[0031] When the radius of curvature of the center of the object side surface of the second lens L2 is R3 and the radius of curvature of the center of the image side surface of the second lens L2 is R4, the conditional expression 0.38≦(R3+R4) / (R3-R4)≦1.37 is satisfied, which defines the shape of the second lens L2 and is advantageous for correcting off-axis aberrations and the like within the range as ultra-thin and wide-angle lenses become more popular. Preferably, the conditional expression 0.61≦(R3+R4) / (R3-R4)≦1.10 is satisfied.

[0032] When the axial thickness of the second lens L2 is d3 and the optical length of the imaging optical lens 10 is TTL, the conditional formula 0.01≦d3 / TTL≦0.06 is satisfied, which is advantageous for realizing compactness within the range of the conditional formula. Preferably, the conditional formula 0.02≦d3 / TTL≦0.05 is satisfied.

[0033] In this embodiment, the object side surface of the third lens L3 is a paraxially convex surface, and the image side surface of the third lens L3 is a paraxially concave surface, and the third lens L3 has a negative refractive power. In other optional embodiments, the object side surface and the image side surface of the third lens L3 may be arranged in other concave-convex distribution situations.

[0034] When the focal length of the imaging optical lens 10 is f and the focal length of the third lens L3 is f3, the conditional expression -3.15≦f3 / f≦-0.62 is satisfied, and the power is reasonably distributed, so that the system has excellent imaging quality and low sensitivity. Preferably, the conditional expression -1.97≦f3 / f≦-0.78 is satisfied.

[0035] When the radius of curvature of the object side surface of the third lens L3 is R5 and the radius of curvature of the image side surface of the third lens L3 is R6, the conditional expression 1.04≦(R5+R6) / (R5-R6)≦4.75 is satisfied, which defines the shape of the third lens L3 and is advantageous for correcting off-axis angle of view aberrations and the like within the range as ultra-thin and wide-angle lenses become more popular. Preferably, the conditional expression 1.67≦(R5+R6) / (R5-R6)≦3.80 is satisfied.

[0036] When the axial thickness of the third lens L3 is d5 and the optical length of the imaging optical lens 10 is TTL, the conditional formula 0.02≦d5 / TTL≦0.07 is satisfied, which is advantageous for realizing compactness within the range of the conditional formula. Preferably, the conditional formula 0.03≦d5 / TTL≦0.06 is satisfied.

[0037] In this embodiment, the fourth lens L4 has an object side surface that is a convex or concave surface paraxially, an image side surface that is a concave or convex surface paraxially, and the fourth lens L4 has positive or negative refractive power.

[0038] When the focal length of the imaging optical lens 10 is f and the focal length of the fourth lens L4 is f4, the conditional expression -34.78≦f4 / f≦28.49 is satisfied, and the power is reasonably distributed so that the system has excellent imaging quality and low sensitivity. Preferably, the conditional expression -21.74≦f4 / f≦22.79 is satisfied.

[0039] When the radius of curvature of the object side surface of the fourth lens L4 is R7 and the radius of curvature of the image side surface of the fourth lens L4 is R8, the conditional expression -5.49≦(R7+R8) / (R7-R8)≦1.62 is satisfied, which defines the shape of the fourth lens L4 and is advantageous for correcting off-axis angle of view aberrations and the like as ultra-thin and wide-angle lenses become more popular within this range. Preferably, the conditional expression -3.43≦(R7+R8) / (R7-R8)≦1.30 is satisfied.

[0040] When the axial thickness of the fourth lens L4 is d7 and the optical length of the imaging optical lens 10 is TTL, the conditional formula 0.02≦d7 / TTL≦0.07 is satisfied, which is advantageous for realizing compactness within the range of the conditional formula. Preferably, the conditional formula 0.02≦d7 / TTL≦0.06 is satisfied.

[0041] In this embodiment, the object side surface of the fifth lens L5 is a paraxially convex surface, and the image side surface of the fifth lens L5 is a paraxially convex surface, and the fifth lens L5 has a positive refractive power. In other optional embodiments, the object side surface and the image side surface of the fifth lens L5 may be disposed in other concave-convex distribution situations.

[0042] When the focal length of the imaging optical lens 10 is f and the focal length of the fifth lens L5 is f5, the condition 0.95≦f5 / f≦3.59 is satisfied, and the power is reasonably distributed so that the system has excellent imaging quality and low sensitivity. Preferably, the condition 1.53≦f5 / f≦2.87 is satisfied.

[0043] When the radius of curvature of the object side surface of the fifth lens L5 is R9 and the radius of curvature of the image side surface of the fifth lens L5 is R10, the conditional expression -0.22≦(R9+R10) / (R9-R10)≦1.00 is satisfied, which defines the shape of the fifth lens L5 and is advantageous for correcting off-axis angle of view aberrations and the like as ultra-thin and wide-angle lenses become more popular within this range. Preferably, the conditional expression -0.14≦(R9+R10) / (R9-R10)≦0.80 is satisfied.

[0044] When the axial thickness of the fifth lens L5 is d9 and the optical length of the imaging optical lens 10 is TTL, the conditional formula 0.04≦d9 / TTL≦0.15 is satisfied, which is advantageous for realizing compactness within the range of the conditional formula. Preferably, the conditional formula 0.06≦d9 / TTL≦0.12 is satisfied.

[0045] In this embodiment, the sixth lens L6 has a paraxially concave object side surface and a paraxially convex image side surface, and the sixth lens L6 has a negative refractive power. In other alternative embodiments, the object side surface and the image side surface of the sixth lens L6 may be arranged in other concave-convex distribution situations.

[0046] When the focal length of the imaging optical lens 10 is f and the focal length of the sixth lens L6 is f6, the conditional expression -4.17≦f6 / f≦-0.60 is satisfied, and the power is reasonably distributed so that the system has excellent imaging quality and low sensitivity. Preferably, the conditional expression -2.61≦f6 / f≦-0.76 is satisfied.

[0047] When the radius of curvature of the center of the object side surface of the sixth lens L6 is R11 and the radius of curvature of the center of the image side surface of the sixth lens L6 is R12, the conditional expression -9.09≦(R11+R12) / (R11-R12)≦-0.92 is satisfied, which defines the shape of the sixth lens L6 and is advantageous for correcting off-axis aberrations and the like as the lens becomes ultra-thin and wide-angle within the range of the conditional expression. Preferably, the conditional expression -5.68≦(R11+R12) / (R11-R12)≦-1.15 is satisfied.

[0048] When the axial thickness of the sixth lens L6 is d11 and the optical length of the imaging optical lens 10 is TTL, the conditional formula 0.02≦d11 / TTL≦0.15 is satisfied, which is advantageous for realizing compactness within the range of the conditional formula. Preferably, the conditional formula 0.03≦d11 / TTL≦0.12 is satisfied.

[0049] In this embodiment, when the image height of the imaging optical lens 10 is IH and the optical length of the imaging optical lens 10 is TTL, the condition TTL / IH≦2.15 is satisfied, which is advantageous for realizing compactness.

[0050] In this embodiment, the aperture value FNO of the imaging optical lens 10 is 1.90 or less, which allows for a large aperture and excellent imaging performance of the imaging optical lens.

[0051] The imaging optical lens 10 has good optical performance and can satisfy the design requirements for large diameter and ultra-thinness. Based on the characteristics of the imaging optical lens 10, the imaging optical lens 10 is particularly applicable to imaging lens assemblies of mobile phones and WEB imaging lenses configured with imaging elements such as CCD and CMOS for high pixel counts.

[0052] The imaging optical lens 10 of the present invention will be described below using examples. Symbols used in each example are as follows. The units of focal length, axial distance, central radius of curvature, axial thickness, inflection point position, and stationary point position are mm.

[0053] TTL: Optical length (the axial distance from the object side of the first lens L1 to the image plane Si) in mm. Aperture No. FNO: The ratio between the effective focal length of an imaging optical lens and the entrance pupil diameter.

[0054] Preferably, in order to meet the demand for high quality imaging, an inflection point and / or a stationary point may be further set on the object side and / or image side of the lens, and a specific embodiment is given below.

[0055] Tables 1 and 2 show design data for the imaging optical lens 10 according to the first embodiment of the present invention.

[0056] [Table 1]

[0057] The meanings of the symbols in the table are as follows: S1: Aperture R: Radius of curvature at the center of the optical surface R1: The central radius of curvature of the object side of the first lens L1 R2: Radius of curvature of the center of the image side of the first lens L1 R3: The central radius of curvature of the object side of the second lens L2 R4: Radius of curvature of the center of the image side of the second lens L2 R5: The central radius of curvature of the object side of the third lens L3 R6: The central radius of curvature of the image side of the third lens L3 R7: The central radius of curvature of the object side of the fourth lens L4 R8: The central radius of curvature of the image side of the fourth lens L4 R9: The central radius of curvature of the object side of the fifth lens L5 R10: Radius of central curvature of the image side of the fifth lens L5 R11: The central radius of curvature of the object side of the sixth lens L6 R12: Radius of curvature of the center of the image side of the sixth lens L6 R13: The central curvature radius of the object side of the optical filter GF R14: Radius of curvature of the center of the image side of the optical filter GF d: Axial thickness of lens, axial distance between lenses d0: The axial distance from the aperture stop S1 to the object side of the first lens L1 d1: Axial thickness of the first lens L1 d2: The axial distance from the image side surface of the first lens L1 to the object side surface of the second lens L2 d3: Axial thickness of the second lens L2 d4: The axial distance from the image side surface of the second lens L2 to the object side surface of the third lens L3 d5: Axial thickness of the third lens L3 d6: The axial distance from the image side surface of the third lens L3 to the object side surface of the fourth lens L4 d7: Axial thickness of the fourth lens L4 d8: The axial distance from the image side surface of the fourth lens L4 to the object side surface of the fifth lens L5 d9: Axial thickness of the fifth lens L5 d10: the axial distance from the image side surface of the fifth lens L5 to the object side surface of the sixth lens L6 d11: Axial thickness of the sixth lens L6 d12: The axial distance from the image side surface of the sixth lens L6 to the object side surface of the optical filter GF d13: On-axis thickness of optical filter GF d14: Axial distance from the image side of the optical filter GF to the image plane Si nd: Refractive index of d line (d line is green light with a wavelength of 550 nm) nd1: refractive index of the d line of the first lens L1 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 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 L3 v4: Abbe number of the fourth lens L4 v5: Abbe number of the fifth lens L5 v6: Abbe number of the sixth lens L6 vg: Abbe number of the optical filter GF

[0058] Table 2 shows the aspheric data of each lens in the imaging optical lens 10 according to the first embodiment of the present invention.

[0059] [Table 2]

[0060] For convenience, the aspheric surface of each lens surface is expressed by the following formula (24). However, the present invention is not limited to the form of the aspheric polynomial shown in this formula (24).

[0061] 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 +A22r 22 +A24r 24 +A26r 26 +A28r 28 +A30r 30 (twenty four)

[0062] where k is a conic coefficient, A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 are aspheric coefficients, c is the curvature at the center 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 at a distance r from the optical axis and a tangent plane that is tangent to the vertex of the aspheric surface on the optical axis).

[0063] Tables 3 and 4 show the design data of the inflection points and stationary points of each lens in the imaging optical lens 10 according to the first embodiment of the present invention. Here, P1R1 and P1R2 indicate the object side surface and image side surface of the first lens L1, P2R1 and P2R2 indicate the object side surface and image side surface of the second lens L2, P3R1 and P3R2 indicate the object side surface and image side surface of the third lens L3, P4R1 and P4R2 indicate the object side surface and image side surface of the fourth lens L4, P5R1 and P5R2 indicate the object side surface and image side surface of the fifth lens L5, and P6R1 and P6R2 indicate the object side surface and image side surface of the sixth lens L6. The corresponding data in the "inflection point position" column is the vertical distance from the inflection point located on the surface of each lens to the optical axis of the imaging optical lens 10. The corresponding data in the “Stay Point Position” column is the vertical distance from the stay point located on the surface of each lens to the optical axis of the imaging optical lens 10 .

[0064] [Table 3]

[0065] [Table 4]

[0066] Fig. 2 and Fig. 3 are schematic diagrams showing the axial chromatic aberration and lateral chromatic aberration of light having wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, 470 nm, and 435 nm after passing through the imaging optical lens 10 according to the first embodiment. Fig. 4 is a schematic diagram showing the field curvature and distortion aberration of light having a wavelength of 555 nm after passing through the imaging optical lens 10 according to the first embodiment, where the field curvature S in Fig. 4 is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0067] Table 25 described later shows various numerical values ​​in each embodiment and values ​​corresponding to parameters defined by conditional expressions.

[0068] As shown in Table 25, the first embodiment satisfies each of the conditional expressions.

[0069] In this embodiment, the imaging optical lens 10 has an entrance pupil diameter ENPD of 3.724 mm, a full field of view image height IH of 3.133 mm, and a diagonal angle of view FOV of 47.57°. The imaging optical lens 10 satisfies the design requirements for a large aperture and an extremely thin shape, has its on-axis and off-axis chromatic aberrations sufficiently corrected, and has excellent optical characteristics.

[0070] Second embodiment The second embodiment is basically the same as the first embodiment, and the symbols have the same meanings as in the first embodiment, so only the differences will be described below.

[0071] FIG. 5 shows an imaging optical lens 20 according to a second embodiment of the present invention.

[0072] Tables 5 and 6 show design data for the imaging optical lens 20 according to the second embodiment of the present invention.

[0073] [Table 5]

[0074] Table 6 shows the aspheric data of each lens in the imaging optical lens 20 according to the second embodiment of the present invention.

[0075] [Table 6]

[0076] Tables 7 and 8 show design data for the inflection points and stationary points of each lens in the imaging optical lens 20 according to the second embodiment of the present invention.

[0077] [Table 7]

[0078] [Table 8]

[0079] Fig. 6 and Fig. 7 are schematic diagrams showing the axial chromatic aberration and the chromatic aberration of magnification after light of wavelengths 650 nm, 610 nm, 555 nm, 510 nm, 470 nm, and 435 nm has passed through the imaging optical lens 20 according to the second embodiment. Fig. 8 is a schematic diagram showing the field curvature and the distortion aberration after light of wavelength 555 nm has passed through the imaging optical lens 20 according to the second embodiment. In Fig. 8, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0080] As shown in Table 25, the second embodiment satisfies each of the conditional expressions.

[0081] In this embodiment, the imaging optical lens 20 has an entrance pupil diameter ENPD of 3.436 mm, a full field of view image height IH of 3.133 mm, and a diagonal angle of view FOV of 50.37°. The imaging optical lens 20 satisfies the design requirements for a large aperture and an extremely thin shape, has its on-axis and off-axis chromatic aberrations sufficiently corrected, and has excellent optical characteristics.

[0082] Third embodiment The third embodiment is basically the same as the first embodiment, and the symbols have the same meanings as in the first embodiment, so only the differences will be described below.

[0083] FIG. 9 shows an imaging optical lens 30 according to a third embodiment of the present invention.

[0084] Tables 9 and 10 show design data for the imaging optical lens 30 according to the third embodiment of the present invention.

[0085] [Table 9]

[0086] Table 10 shows the aspheric data of each lens in the imaging optical lens 30 according to the third embodiment of the present invention.

[0087] [Table 10]

[0088] Tables 11 and 12 show design data for the inflection points and stationary points of each lens in the imaging optical lens 30 according to the third embodiment of the present invention.

[0089] [Table 11]

[0090] [Table 12]

[0091] Fig. 10 and Fig. 11 are schematic diagrams showing the axial chromatic aberration and the chromatic aberration of magnification after light of wavelengths 650 nm, 610 nm, 555 nm, 510 nm, 470 nm, and 435 nm has passed through the imaging optical lens 30 according to the third embodiment. Fig. 12 is a schematic diagram showing the field curvature and the distortion aberration after light of wavelength 555 nm has passed through the imaging optical lens 20 according to the second embodiment. In Fig. 12, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0092] As shown in Table 25, the third embodiment satisfies each of the conditional expressions.

[0093] In this embodiment, the imaging optical lens 30 has an entrance pupil diameter ENPD of 3.715 mm, a full field of view image height IH of 3.133 mm, and a diagonal angle of view FOV of 47.65°. The imaging optical lens 30 satisfies the design requirements for a large aperture and an extremely thin shape, has its on-axis and off-axis chromatic aberrations sufficiently corrected, and has excellent optical characteristics.

[0094] (Fourth embodiment) The fourth embodiment is basically the same as the first embodiment, and the symbols have the same meanings as in the first embodiment, so only the differences will be described below.

[0095] FIG. 13 shows an imaging optical lens 40 according to a fourth embodiment of the present invention.

[0096] Tables 13 and 14 show design data for the imaging optical lens 40 according to the fourth embodiment of the present invention.

[0097] [Table 13]

[0098] Table 14 shows the aspheric data of each lens in the imaging optical lens 40 according to the fourth embodiment of the present invention.

[0099] [Table 14]

[0100] Tables 15 and 16 show design data for the inflection points and stationary points of each lens in the imaging optical lens 40 according to the fourth embodiment of the present invention.

[0101] [Table 15]

[0102] [Table 16]

[0103] Fig. 14 and Fig. 15 are schematic diagrams showing the axial chromatic aberration and the chromatic aberration of magnification after light having wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, 470 nm, and 435 nm passes through the imaging optical lens 40 according to the fourth embodiment. Fig. 16 is a schematic diagram showing the field curvature and the distortion aberration after light having wavelength of 555 nm passes through the imaging optical lens 40 according to the fourth embodiment. In Fig. 16, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0104] As shown in Table 25, the fourth embodiment satisfies each of the conditional expressions.

[0105] In this embodiment, the imaging optical lens 40 has an entrance pupil diameter ENPD of 3.397 mm, a full field of view image height IH of 3.133 mm, and a diagonal angle of view FOV of 47.82°. The imaging optical lens 40 satisfies the design requirements for a large aperture and an extremely thin shape, has its on-axis and off-axis chromatic aberrations sufficiently corrected, and has excellent optical characteristics.

[0106] Fifth embodiment The fifth embodiment is basically the same as the first embodiment, and the symbols have the same meanings as in the first embodiment, so only the differences will be described below.

[0107] FIG. 17 shows an imaging optical lens 50 according to a fifth embodiment of the present invention.

[0108] Tables 17 and 18 show design data for the imaging optical lens 50 according to the fifth embodiment of the present invention.

[0109] [Table 17]

[0110] Table 18 shows the aspheric data of each lens in the imaging optical lens 50 according to the fifth embodiment of the present invention.

[0111] [Table 18]

[0112] Tables 19 and 20 show design data for the inflection points and stationary points of each lens in the imaging optical lens 50 according to the fifth embodiment of the present invention.

[0113] [Table 19]

[0114] [Table 20]

[0115] Fig. 18 and Fig. 19 are schematic diagrams showing the axial chromatic aberration and the chromatic aberration of magnification after light of wavelengths 650 nm, 610 nm, 555 nm, 510 nm, 470 nm, and 435 nm has passed through the imaging optical lens 50 according to the fifth embodiment. Fig. 20 is a schematic diagram showing the field curvature and distortion aberration after light of wavelength 555 nm has passed 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 tangential direction.

[0116] As shown in Table 25, the fifth embodiment satisfies each of the conditional expressions.

[0117] In this embodiment, the imaging optical lens 50 has an entrance pupil diameter ENPD of 3.919 mm, a full field of view image height IH of 3.133 mm, and a diagonal angle of view FOV of 45.72°. The imaging optical lens 50 satisfies the design requirements for a large aperture and an extremely thin shape, has its on-axis and off-axis chromatic aberrations sufficiently corrected, and has excellent optical characteristics.

[0118] (Comparative embodiment) The meanings of the symbols in the comparative embodiment are the same as those in the first embodiment, so only the differences are shown below.

[0119] FIG. 21 shows an imaging optical lens 60 according to a comparative embodiment.

[0120] Tables 21 and 22 show design data for the imaging optical lens 60 according to the comparative embodiment.

[0121] [Table 21]

[0122] Table 22 shows the aspheric data of each lens in the imaging optical lens 60 according to the comparative embodiment.

[0123] [Table 22]

[0124] Tables 23 and 24 show the design data of the inflection points and stationary points of each lens in the imaging optical lens 60 according to the comparative embodiment.

[0125] [Table 23]

[0126] [Table 24]

[0127] Fig. 22 and Fig. 23 are schematic diagrams showing the axial chromatic aberration and the chromatic aberration of magnification after light of wavelengths 650 nm, 610 nm, 555 nm, 510 nm, 470 nm, and 435 nm passes through the imaging optical lens 60 according to the comparative embodiment. Fig. 24 is a schematic diagram showing the field curvature and the distortion aberration after light of wavelength 555 nm passes through the imaging optical lens 60 according to the comparative embodiment. In Fig. 24, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0128] In Table 25 below, numerical values ​​corresponding to each condition in the comparative embodiment are listed according to the above condition. Apparently, the imaging optical lens 60 according to the comparative embodiment does not satisfy the above condition 0.10≦d8 / TTL≦0.20.

[0129] In the comparative embodiment, the entrance pupil diameter ENPD of the imaging optical lens 60 is 3.625 mm, the full field of view image height IH is 3.133 mm, and the diagonal field of view FOV is 41.50°, and the imaging optical lens 60 does not satisfy the design requirements for a large diameter and an extremely thin shape.

[0130] [Table 25]

[0131] As will be understood by those skilled in the art, the above-described embodiments are specific embodiments for realizing the present invention, and in actual application, various changes in form and details are possible without departing from the spirit and scope of the present invention.

Claims

1. 1. An imaging optical lens, comprising: the imaging optical lens is composed of, in order from the object side to the image side, a first lens having positive refractive power, a second lens having negative refractive power, a third lens having negative refractive power, a fourth lens having refractive power, a fifth lens having positive refractive power, and a sixth lens having negative refractive power; an optical lens satisfying the following conditional expressions (1) to (4): a focal length of the second lens is f2, a focal length of the third lens is f3, an axial distance from the image side surface of the fourth lens to the object side surface of the fifth lens is d8, a central radius of curvature of the object side surface of the fifth lens is R9, a central radius of curvature of the image side surface of the fifth lens is R10, an optical length of the imaging optical lens is TTL, a central radius of curvature of the object side surface of the sixth lens is R11, and a central radius of curvature of the image side surface of the sixth lens is R12. 0.10≦d8 / TTL≦0.20 (1) −5.00≦R9 / R10≦−0.80 (2) 0.70≦f2 / f3≦1.00 (3) 0.16≦R11 / R12≦0.64 (4)

2. An imaging optical lens, the imaging optical lens is composed of, in order from the object side to the image side, a first lens having positive refractive power, a second lens having negative refractive power, a third lens having negative refractive power, a fourth lens having refractive power, a fifth lens having positive refractive power, and a sixth lens having negative refractive power; an imaging optical lens satisfying the following conditional expressions (1) to (3) and (5): 0.10≦d8 / TTL≦0.20 (1) −5.00≦R9 / R10≦−0.80 (2) 0.70≦f2 / f3≦1.00 (3) 0.40≦f1 / f≦0.50 (5)

3. An imaging optical lens, the imaging optical lens is composed of, in order from the object side to the image side, a first lens having positive refractive power, a second lens having negative refractive power, a third lens having negative refractive power, a fourth lens having refractive power, a fifth lens having positive refractive power, and a sixth lens having negative refractive power; an axial distance from the image side surface of the fourth lens to the object side surface of the fifth lens is d8; a central radius of curvature of the object side surface of the fifth lens is R9; a central radius of curvature of the image side surface of the fifth lens is R10; an optical length of the imaging optical lens is TTL; an axial distance from the image side surface of the third lens to the object side surface of the fourth lens is d6; and an axial thickness of the fourth lens is d7. 0.10≦d8 / TTL≦0.20 (1) −5.00≦R9 / R10≦−0.80 (2) 0.70≦f2 / f3≦1.00 (3) 2.00≦d6 / d7≦4.00 (6)

4. an object side surface of the first lens is a paraxially convex surface, and an image side surface of the first lens is a paraxially convex surface, 4. The imaging optical lens according to claim 1, wherein the imaging optical lens satisfies the following conditional expressions (7) to (8), where R1 is a central radius of curvature of an object-side surface of the first lens, R2 is a central radius of curvature of an image-side surface of the first lens, and d1 is an axial thickness of the first lens. -1.25≦(R1+R2) / (R1-R2)≦-0.32 (7) 0.10≦d1 / TTL≦0.34 (8)

5. an object side surface of the second lens is a paraxially concave surface, and an image side surface of the second lens is a paraxially concave surface, 4. The imaging optical lens according to claim 1, wherein the imaging optical lens satisfies the following conditional expressions (9) to (11), where f is a focal length of the imaging optical lens, R3 is a central radius of curvature of the object side surface of the second lens, R4 is a central radius of curvature of the image side surface of the second lens, and d3 is an axial thickness of the second lens. −2.25≦f2 / f≦−0.61 (9) 0.38≦(R3+R4) / (R3-R4)≦1.37 (10) 0.01≦d3 / TTL≦0.06 (11)

6. an object side surface of the third lens is a paraxially convex surface, and an image side surface of the third lens is a paraxially concave surface, The imaging optical lens according to any one of claims 1 to 3, characterized in that the imaging optical lens satisfies the following conditional expressions (12) to (14), where f is a focal length of the imaging optical lens, R5 is a central radius of curvature of the object side surface of the third lens, R6 is a central radius of curvature of the image side surface of the third lens, and d5 is an axial thickness of the third lens. −3.15≦f3 / f≦−0.62 (12) 1.04≦(R5+R6) / (R5-R6)≦4.75 (13) 0.02≦d5 / TTL≦0.07 (14)

7. 4. The imaging optical lens according to claim 1, wherein the imaging optical lens satisfies the following conditional expressions (15) to (17): −34.78≦f4 / f≦28.49 (15) -5.49≦(R7+R8) / (R7-R8)≦1.62 (16) 0.02≦d7 / TTL≦0.07 (17)

8. an object side surface of the fifth lens is a paraxially convex surface, and an image side surface of the fifth lens is a paraxially convex surface, The imaging optical lens according to any one of claims 1 to 3, characterized in that, when a focal length of the imaging optical lens is f, a focal length of the fifth lens is f5, and an axial thickness of the fifth lens is d9, the imaging optical lens satisfies the following conditional expressions (18) to (20): 0.95≦f5 / f≦3.59 (18) -0.22≦(R9+R10) / (R9-R10)≦1.00 (19) 0.04≦d9 / TTL≦0.15 (20)

9. an object side surface of the sixth lens is a paraxial concave surface, and an image side surface of the sixth lens is a paraxial convex surface, the imaging optical lens according to any one of claims 1 to 3, wherein the imaging optical lens satisfies the following conditional expressions (21) to (23), where the focal length of the imaging optical lens is f, the focal length of the sixth lens is f6, the central radius of curvature of the object side surface of the sixth lens is R11, the central radius of curvature of the image side surface of the sixth lens is R12, and the axial thickness of the sixth lens is d11. −4.17≦f6 / f≦−0.60 (21) -9.09≦(R11+R12) / (R11-R12)≦-0.92 (22) 0.02≦d11 / TTL≦0.15 (23)

Images