imaging optical lens

Abstract

This invention relates to the field of optical lenses and provides an imaging optical lens. [Solution] The imaging optical lens is composed of a total of seven lenses, which, in order from the object side to the image side, are a first lens with negative refractive power, a second lens with negative refractive power, a third lens with refractive power, a fourth lens with positive refractive power, a fifth lens with positive refractive power, a sixth lens with positive refractive power, and a seventh lens with negative refractive power. The focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the central radius of curvature of the third lens at the paraxial side of the object side is R5, the central radius of curvature of the third lens at the paraxial side of the image side is R6, the field of view at 1.0x the imaging optical lens is FOV, the aperture value is Fno, and the following conditions are met: 1.50 ≤ f4 / f5 ≤ 3.40, 0.90 ≤ R5 / R6 ≤ 1.40, and 170 ≤ FOV / Fno ≤ 200.

Description

Technical Field

[0001] The present invention relates to the field of optical lenses, and particularly to an imaging optical lens applicable to portable terminal devices such as smartphones and digital cameras, and imaging devices such as monitors, PC lenses, and in-vehicle lenses.

Background Art

[0002] In recent years, with the development of various smart devices, the demand for miniaturized imaging optical lenses has been increasing. In addition to the reduction of the pixel size of photosensitive elements, current electronic products are developing towards a high-functional, lightweight, thin, and portable form factor. Therefore, miniaturized imaging optical lenses with good imaging quality are currently the mainstream in the market. To obtain excellent imaging quality, a multi-lens structure is often adopted. Also, with the development of technology and the increasing diversification of user needs, when the pixel area of the photosensitive element is shrinking and the requirements for imaging quality from the system are increasing, a seven-lens structure is gradually emerging in lens design. The demand for a wide-angle imaging lens with excellent optical characteristics, large aperture, wide-angle, extremely thin, and sufficient aberration correction is becoming urgent.

Summary of the Invention

Problems 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 at the same time satisfies the design requirements of sufficient aberration correction, large aperture, wide-angle, and extremely thin.

Means for Solving the Problems

[0004] To achieve the above objective, the present invention provides an imaging optical lens. The imaging optical lens is composed of a total of seven lenses, the seven lenses being, in order from the object side to the image side, a first lens with negative refractive power, a second lens with negative refractive power, a third lens with refractive power, a fourth lens with positive refractive power, a fifth lens with positive refractive power, a sixth lens with positive refractive power, and a seventh lens with negative refractive power, the focal length of the fourth lens being f4, the focal length of the fifth lens being f5, the central radius of curvature of the third lens at the paraxial side of the object side being R5, the central radius of curvature of the third lens at the paraxial side of the image side being R6, the angle of view of the imaging optical lens at 1.0x magnification being FOV, the aperture value of the imaging optical lens being Fno, and satisfying the following conditions (1) to (3). 1.50 ≤ f4 / f5 ≤ 3.40 (1) 0.90 ≤ R5 / R6 ≤ 1.40 (2) 170.00 ≤ FOV / Fno ≤ 200.00 (3)

[0005] Preferably, the Abbe number of the sixth lens is v6, the Abbe number of the seventh lens is v7, and the following condition (4) is satisfied. v6-v7≧35.00 (4)

[0006] Preferably, the on-axial distance from the image side of the seventh lens to the image plane is BF, the total optical length of the imaging optical lens is TTL, and the following condition (5) is satisfied. 0.09 ≤ BF / TTL ≤ 0.15 (5)

[0007] Preferably, the focal length of the second lens is f2, the on-axial thickness of the second lens is d3, and the following condition (6) is satisfied. 8.80 ≤ |f² / d³| ≤ 13.00 (6)

[0008] Preferably, the first lens has a convex surface on the paraxial side of the object side and a concave surface on the paraxial side of the image side, the focal length of the imaging optical lens is f, the focal length of the first lens is f1, the central radius of curvature of the object side of the first lens on the paraxial side is R1, the central radius of curvature of the image side of the first lens on the paraxial side is R2, the on-axial thickness of the first lens is d1, the total optical length of the imaging optical lens is TTL, and satisfies the following conditions (7) to (9). -13.18 ≤ f1 / f ≤ -3.84 (7) 0.75≦(R1+R2) / (R1-R2)≦2.64 (8) 0.02 ≤ d1 / TTL ≤ 0.24 (9)

[0009] Preferably, the second lens has an object side surface that is concave in the paraxial direction and an image side surface that is concave in the paraxial direction, the focal length of the imaging optical lens is f, the focal length of the second lens is f2, the central radius of curvature of the object side surface of the second lens in the paraxial direction is R3, the central radius of curvature of the image side surface of the second lens in the paraxial direction is R4, the on-axial thickness of the second lens is d3, the total optical length of the imaging optical lens is TTL, and satisfies the following conditions (10) to (12). -7.57 ≤ f² / f ≤ -2.15 (10) 0.21≦(R3+R4) / (R3-R4)≦0.74 (11) 0.01 ≤ d3 / TTL ≤ 0.04 (12)

[0010] Preferably, the third lens has a concave surface on the paraxial side of the object and a convex surface on the paraxial side of the image, the focal length of the imaging optical lens is f, the focal length of the third lens is f3, the on-axial thickness of the third lens is d5, the total optical length of the imaging optical lens is TTL, and satisfies the following conditions (13) to (15). -3743.34 ≤ f3 / f ≤ 88.10 (13) -39.92≦(R5+R6) / (R5-R6)≦18.19 (14) 0.07 ≤ d5 / TTL ≤ 0.25 (15)

[0011] Preferably, the fourth lens has a concave surface on the paraxial side of the object side and a convex surface on the paraxial side of the image side, the focal length of the imaging optical lens is f, the central radius of curvature of the object side of the fourth lens on the paraxial side is R7, the central radius of curvature of the image side of the fourth lens on the paraxial side is R8, the on-axial thickness of the fourth lens is d7, the total optical length of the imaging optical lens is TTL, and satisfies the following conditions (16) to (18). 2.45 ≤ f₄ / f ≤ 14.08 (16) 0.72≦(R7+R8) / (R7-R8)≦3.62 (17) 0.03 ≤ d7 / TTL ≤ 0.15 (18)

[0012] Preferably, the fifth lens has an object side surface that is convex in the paraxial direction, an image side surface that is convex in the paraxial direction, the focal length of the imaging optical lens is f, the central radius of curvature of the object side surface of the fifth lens in the paraxial direction is R9, the central radius of curvature of the image side surface of the fifth lens in the paraxial direction is R10, the on-axial thickness of the fifth lens is d9, the total optical length of the imaging optical lens is TTL, and satisfies the following conditions (19) to (21). 1.29 ≤ f5 / f ≤ 4.85 (19) 0.03≦(R9+R10) / (R9-R10)≦0.33 (20) 0.04 ≤ d9 / TTL ≤ 0.19 (21)

[0013] Preferably, the first lens is made of glass. [Effects of the Invention]

[0014] The beneficial effects of the present invention are as follows: The imaging optical lens according to the present invention has excellent optical properties, sufficient aberration correction, large aperture, wide angle, and ultra-thin design, and is particularly applicable to imaging lens units for mobile phones, web imaging lenses, and automotive lenses composed of image sensors such as CCDs and CMOSs ​​for high pixel counts. [Brief explanation of the drawing]

[0015] [Figure 1] It is a schematic diagram showing the configuration of an imaging optical lens according to the first embodiment of the present invention. [Figure 2] It is a schematic diagram showing the axial aberration of the imaging optical lens shown in FIG. 1. [Figure 3] It is a schematic diagram showing the lateral chromatic aberration of the imaging optical lens shown in FIG. 1. [Figure 4] It is a schematic diagram showing the field curvature and distortion of the imaging optical lens shown in FIG. 1. [Figure 5] It is a schematic diagram showing the configuration of an imaging optical lens according to the second embodiment of the present invention. [Figure 6] It is a schematic diagram showing the axial aberration of the imaging optical lens shown in FIG. 5. [Figure 7] It is a schematic diagram showing the lateral chromatic aberration of the imaging optical lens shown in FIG. 5. [Figure 8] It is a schematic diagram showing the field curvature and distortion of the imaging optical lens shown in FIG. 5. [Figure 9] It is a schematic diagram showing the configuration of an imaging optical lens according to the third embodiment of the present invention. [Figure 10] It is a schematic diagram showing the axial aberration of the imaging optical lens shown in FIG. 9. [Figure 11] It is a schematic diagram showing the lateral chromatic aberration of the imaging optical lens shown in FIG. 9. [Figure 12] It is a schematic diagram showing the field curvature and distortion of the imaging optical lens shown in FIG. 9. [Figure 13] It is a schematic diagram showing the configuration of an imaging optical lens according to the fourth embodiment of the present invention. [Figure 14] It is a schematic diagram showing the axial aberration of the imaging optical lens shown in FIG. 13. [Figure 15] It is a schematic diagram showing the lateral chromatic aberration of the imaging optical lens shown in FIG. 13. [Figure 16] It is a schematic diagram showing the field curvature and distortion of the imaging optical lens shown in FIG. 13. [Figure 17] It is a schematic diagram showing the configuration of an imaging optical lens according to the fifth embodiment of the present invention. [Figure 18] It is a schematic diagram showing the axial aberration of the imaging optical lens shown in FIG. 17. [Figure 19] Figure 17 is a schematic diagram showing the chromatic aberration of the imaging optical lens. [Figure 20] Figure 17 is a schematic diagram showing the field curvature and distortion of the imaging optical lens. [Figure 21] This is a schematic diagram showing the configuration of an imaging optical lens according to the sixth embodiment of the present invention. [Figure 22] Figure 21 is a schematic diagram showing the axial aberration of the imaging optical lens. [Figure 23] Figure 21 is a schematic diagram showing the chromatic aberration of the imaging optical lens. [Figure 24] Figure 21 is a schematic diagram showing the field curvature and distortion of the imaging optical lens. [Figure 25] This is a schematic diagram showing the configuration of an imaging optical lens according to the seventh embodiment of the present invention. [Figure 26] Figure 25 is a schematic diagram showing the axial aberration of the imaging optical lens. [Figure 27] Figure 25 is a schematic diagram showing the chromatic aberration of the imaging optical lens. [Figure 28] Figure 25 is a schematic diagram showing the field curvature and distortion of the imaging optical lens. [Figure 29] This is a schematic diagram showing the configuration of the imaging optical lens according to the comparative embodiment. [Figure 30] Figure 29 is a schematic diagram showing the axial aberration of the imaging optical lens. [Figure 31] Figure 29 is a schematic diagram showing the chromatic aberration of the imaging optical lens. [Figure 32] Figure 29 is a schematic diagram showing the field curvature and distortion of the imaging optical lens. [Modes for carrying out the invention]

[0016] To more clearly explain the technical concepts of the embodiments of the present invention, the necessary drawings for the embodiments are briefly introduced below. Clearly, the drawings described below represent only a few embodiments of the present invention, and those skilled in the art can obtain further drawings based on these drawings without any creative work. To make the object, technical proposal, and merits of the present invention clearer, each embodiment of the present invention will be described in detail below with reference to the drawings. It will be apparent to those skilled in the art that many technical details are described in each embodiment of the present invention to better understand the present invention. However, the technical proposal to be protected by the present invention can be realized without these technical details and the various changes and modifications based on the following embodiments.

[0017] As shown in Figures 1 to 28, the present invention provides imaging optical lenses 10, 20, 30, 40, 50, 60, and 70. Figures 1, 5, 9, 13, 17, 21, and 25 show the imaging optical lenses 10, 20, 30, 40, 50, 60, and 70 of the present invention, which comprise a total of seven lenses. Specifically, the imaging optical lenses, in order from the object side to the image side, are the first lens L1, the second lens L2, the third lens L3, the aperture S1, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the 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.

[0018] The first lens L1 is made of glass, the second lens L2 is made of plastic, the third lens L3 is made of plastic, the fourth lens L4 is made of plastic, the fifth lens L5 is made of plastic, the sixth lens L6 is made of plastic, and the seventh lens L7 is made of plastic. By combining glass and resin lenses, chromatic aberration is reduced and the performance of the optical imaging lens is improved. Each lens may be made of other materials.

[0019] If we define the focal length of the fourth lens L4 as f4 and the focal length of the fifth lens L5 as f5, then the condition 1.50 ≤ f4 / f5 ≤ 3.40 is satisfied. This condition limits the ratio of the focal lengths of the fourth and fifth lenses, and within the range of the condition, the system's optical focal lengths are rationally distributed, contributing to a gradual transition of light rays, resulting in a system with excellent image quality and low sensitivity.

[0020] If we define R5 as the central radius of curvature of the paraxial side of the object surface of the third lens L3, and R6 as the central radius of curvature of the paraxial side of the image surface of the third lens L3, then the condition 0.90 ≤ R5 / R6 ≤ 1.40 is satisfied. This condition limits the shape of the third lens, and within the range of the condition, it effectively mitigates the wide-angle rays that have been bent after passing through the first lens L1 and the second lens L2, effectively balances the amount of field curvature of the system, and makes the offset amount of field curvature in the central field of view less than 0.02 mm.

[0021] If we define the field of view at 1.0x the imaging optical lens as the FOV and the aperture value of the imaging optical lens as Fno, then the condition 170.00 ≤ FOV / Fno ≤ 200.00 is satisfied. This condition limits the range of the ratio between the field of view and the aperture, and within this range, ultra-large aperture and ultra-wide angle are achieved, satisfying application needs and expanding the range of product applications.

[0022] If we define the Abbe number of the sixth lens L6 as ν6 and the Abbe number of the seventh lens L7 as ν7, then the condition ν6 - ν7 ≥ 35.00 is satisfied. This condition limits the difference in Abbe numbers of the cemented lenses, effectively distributes the material attributes within the range of the condition, effectively corrects chromatic aberration, and sets chromatic aberration |LC| ≤ 4 μm.

[0023] If we define BF as the on-axial distance from the image side of the seventh lens L7 to the image plane Si, and TTL as the total optical length of the imaging optical lens, then the condition 0.09 ≤ BF / TTL ≤ 0.15 is satisfied. Within this range, miniaturization is achieved while reducing the back focal length, which is advantageous for module assembly.

[0024] If we define the focal length of the second lens L2 as f2 and the on-axial thickness of the second lens L2 as d3, the condition 8.80 ≤ |f2 / d3| ≤ 13.00 is satisfied. Within this range, the change in the incident angle of high-angle light rays is buffered, allowing them to propagate smoothly within the optical imaging lens group, while maintaining the refractive power of the second lens, improving chromatic aberration, and contributing to improved image quality.

[0025] When the above conditions are met, the imaging optical lenses 10, 20, 30, 40, 50, 60, and 70 have good optical performance and can meet the design requirements for large aperture and wide angle. Depending on the characteristics of the imaging optical lenses 10, 20, 30, 40, 50, 60, and 70, they are particularly applicable to imaging lens units and web imaging lenses for mobile phones composed of image sensors such as CCDs and CMOSs ​​for high pixel counts.

[0026] Based on the above conditions and feasible functions, the further subdivided characteristics of each lens are as follows:

[0027] The first lens L1 has an object side that is convex in the paraxial direction and an image side that is concave in the paraxial direction, and the first lens L1 has negative refractive power. The object side and image side of the first lens L1 may be set up in other concave / convex distribution configurations.

[0028] If we define the focal length of the imaging optical lens as f and the focal length of the first lens L1 as f1, then the condition -13.18 ≤ f1 / f ≤ -3.84 is satisfied. This condition limits the ratio of the negative refractive power of the first lens L1 to the total focal length. Within the range of this condition, the first lens L1 has an appropriate negative refractive power, which is advantageous for reducing system aberrations and also for making the lens extremely thin and wide-angle. Preferably, the condition -8.24 ≤ f1 / f ≤ -4.80 is satisfied.

[0029] If we define R1 as the central radius of curvature of the paraxial side of the object surface of the first lens L1, and R2 as the central radius of curvature of the paraxial side of the image surface of the first lens L1, then the condition 0.75 ≤ (R1 + R2) / (R1 - R2) ≤ 2.64 is satisfied. By rationally controlling the shape of the first lens L1, the spherical aberration of the system can be effectively corrected by the first lens L1. Preferably, the condition 1.19 ≤ (R1 + R2) / (R1 - R2) ≤ 2.11 is satisfied.

[0030] If we define the on-axial thickness of the first lens L1 as d1 and the total optical length of the imaging optical lens as TTL, then the condition 0.02 ≤ d1 / TTL ≤ 0.24 is satisfied. Within this range, it is advantageous for miniaturization. Preferably, the condition 0.04 ≤ d1 / TTL ≤ 0.19 is satisfied.

[0031] The second lens L2 has an object side that is concave in the paraxial direction and an image side that is concave in the paraxial direction, and the second lens L2 has negative refractive power. The object side and image side of the second lens L2 may be set up in other concave / convex distribution conditions.

[0032] If we define the focal length of the imaging optical lens as f and the focal length of the second lens L2 as f2, then the condition -7.57 ≤ f2 / f ≤ -2.15 is satisfied. Defining the negative refractive power of the second lens L2 within a reasonable range is advantageous for correcting aberrations in the optical system. Preferably, the condition -4.73 ≤ f2 / f ≤ -2.69 is satisfied.

[0033] If we define R3 as the central radius of curvature of the paraxial side of the object surface of the second lens L2, and R4 as the central radius of curvature of the paraxial side of the image surface of the second lens L2, then the condition 0.21 ≤ (R3 + R4) / (R3 - R4) ≤ 0.74 is satisfied. This condition limits the shape of the second lens L2, and within this range, it is advantageous for correcting axial aberrations as ultra-thin and wide-angle lenses become more efficient. Preferably, the condition 0.34 ≤ (R3 + R4) / (R3 - R4) ≤ 0.60 is satisfied.

[0034] If we define the on-axial thickness of the second lens L2 as d3 and the total optical length of the imaging optical lens as TTL, then the condition 0.01 ≤ d3 / TTL ≤ 0.04 is satisfied. Within this range, it is advantageous for miniaturization. Preferably, the condition 0.01 ≤ d3 / TTL ≤ 0.03 is satisfied.

[0035] The third lens L3 has an object side that is concave in the paraxial direction and an image side that is convex in the paraxial direction, and the third lens L3 has either positive or negative refractive power. The object side and image side of the third lens L3 may be set up in other concave / convex distribution configurations.

[0036] If we define the focal length of the imaging optical lens as f and the focal length of the third lens L3 as f3, then the condition -3743.34 ≤ f3 / f ≤ 88.10 is satisfied. Due to the rational distribution of refractive power, the system has excellent image quality and low sensitivity. Preferably, the condition -2339.59 ≤ f3 / f ≤ 70.48 is satisfied.

[0037] If we define R5 as the central radius of curvature of the paraxial side of the object surface of the third lens L3, and R6 as the central radius of curvature of the paraxial side of the image surface of the third lens L3, then the condition -39.92 ≤ (R5 + R6) / (R5 - R6) ≤ 18.19 is satisfied. Within this range, the shape of the third lens L3 can be effectively controlled, which is advantageous for molding the third lens L3 and avoids molding defects and stress generation due to excessive curvature of the surface of the third lens L3. Preferably, the condition -24.95 ≤ (R5 + R6) / (R5 - R6) ≤ 14.55 is satisfied.

[0038] If we define the on-axial thickness of the third lens L3 as d5 and the total optical length of the imaging optical lens as TTL, then the condition 0.07 ≤ d5 / TTL ≤ 0.25 is satisfied. Within this range, it is advantageous for miniaturization. Preferably, the condition 0.12 ≤ d5 / TTL ≤ 0.20 is satisfied.

[0039] The fourth lens L4 has a concave surface on the paraxial side of the object surface and a convex surface on the paraxial side of the image surface, and the fourth lens L4 has a positive refractive power. The object surface and image surface of the fourth lens L4 may be set up in other concave / convex distribution configurations.

[0040] If we define the focal length of the imaging optical lens as f and the focal length of the fourth lens L4 as f4, then the condition 2.45 ≤ f4 / f ≤ 14.08 is satisfied. Due to the rational distribution of refractive power, the system has excellent image quality and low sensitivity. Preferably, the condition 3.92 ≤ f4 / f ≤ 11.27 is satisfied.

[0041] If we define R7 as the central radius of curvature of the paraxial side of the object surface of the fourth lens L4 and R8 as the central radius of curvature of the paraxial side of the image surface of the fourth lens L4, then the condition 0.72 ≤ (R7 + R8) / (R7 - R8) ≤ 3.62 is satisfied. This condition limits the shape of the fourth lens L4, and within the range of the condition, as the lens becomes thinner and wider angle-of-view, it is advantageous for correcting off-axis angle-of-view aberrations. Preferably, the condition 1.16 ≤ (R7 + R8) / (R7 - R8) ≤ 2.90 is satisfied.

[0042] If we define the on-axial thickness of the fourth lens L4 as d7 and the total optical length of the imaging optical lens as TTL, then the condition 0.03 ≤ d7 / TTL ≤ 0.15 is satisfied. Within this range, it is advantageous for miniaturization. Preferably, the condition 0.05 ≤ d7 / TTL ≤ 0.12 is satisfied.

[0043] The fifth lens L5 has an object side that is convex in the paraxial direction and an image side that is convex in the paraxial direction, and the fifth lens L5 has a positive refractive power. The object side and image side of the fifth lens L5 may be set up in other concave / convex distribution conditions.

[0044] If we define the focal length of the imaging optical lens as f and the focal length of the fifth lens L5 as f5, then the condition 1.29 ≤ f5 / f ≤ 4.85 is satisfied. By limiting the fifth lens L5, the ray angle of the imaging optical lens can be effectively made gentler, and the tolerance sensitivity can be reduced. Preferably, the condition 2.06 ≤ f5 / f ≤ 3.88 is satisfied.

[0045] If we define R9 as the central radius of curvature of the paraxial side of the object surface of the fifth lens L5, and R10 as the central radius of curvature of the paraxial side of the image surface of the fifth lens L5, then the condition 0.03 ≤ (R9 + R10) / (R9 - R10) ≤ 0.33 is satisfied. This condition limits the shape of the fifth lens L5, and within the range of the condition, as the lens becomes thinner and wider angle-oriented, it becomes advantageous for correcting aberrations such as off-axis angle of view. Preferably, the condition 0.04 ≤ (R9 + R10) / (R9 - R10) ≤ 0.26 is satisfied.

[0046] If we define the on-axial thickness of the fifth lens L5 as d9 and the total optical length of the imaging optical lens as TTL, then the condition 0.04 ≤ d9 / TTL ≤ 0.19 is satisfied. Within this range, it is advantageous for miniaturization. Preferably, the condition 0.07 ≤ d9 / TTL ≤ 0.16 is satisfied.

[0047] The sixth lens L6 has an object side that is concave in the paraxial direction and an image side that is convex in the paraxial direction, and the sixth lens L6 has a positive refractive power. The object side and image side of the sixth lens L6 may be set up in other concave / convex distribution configurations.

[0048] If we define the focal length of the imaging optical lens as f and the focal length of the sixth lens L6 as f6, then the condition 0.86 ≤ f6 / f ≤ 2.89 is satisfied. Due to the rational distribution of refractive power, the system has excellent image quality and low sensitivity. Preferably, the condition 1.38 ≤ f6 / f ≤ 2.31 is satisfied.

[0049] If we define R11 as the central radius of curvature of the paraxial side of the object surface of the sixth lens L6 and R12 as the central radius of curvature of the paraxial side of the image surface of the sixth lens L6, then the condition 0.59 ≤ (R11 + R12) / (R11 - R12) ≤ 1.93 is satisfied. This condition limits the shape of the sixth lens L6, and within the range of the condition, as the lens becomes thinner and wider angle-of-view, it is advantageous for correcting off-axis angle-of-view aberrations. Preferably, the condition 0.94 ≤ (R11 + R12) / (R11 - R12) ≤ 1.54 is satisfied.

[0050] If we define the axial thickness of the sixth lens L6 as d11 and the total optical length of the imaging optical lens 10 as TTL, then the condition 0.06 ≤ d11 / TTL ≤ 0.22 is satisfied. Within this range, it is advantageous for miniaturization. Preferably, the condition 0.10 ≤ d11 / TTL ≤ 0.17 is satisfied.

[0051] The seventh lens L7 has an object side that is concave in the paraxial direction and an image side that is convex in the paraxial direction, and the seventh lens L7 has negative refractive power. The object side and image side of the sixth lens L6 may be set to have other concave / convex distributions.

[0052] If we define the focal length of the imaging optical lens as f and the focal length of the seventh lens L7 as f7, then the condition -4.26 ≤ f7 / f ≤ -1.22 is satisfied. Due to the rational distribution of refractive power, the system has excellent image quality and low sensitivity. Preferably, the condition -2.66 ≤ f7 / f ≤ -1.52 is satisfied.

[0053] If we define R13 as the central radius of curvature of the paraxial side of the object surface of the seventh lens L7 and R14 as the central radius of curvature of the paraxial side of the image surface of the seventh lens L7, then the condition -3.05 ≤ (R13 + R14) / (R13 - R14) ≤ -0.98 is satisfied. This condition limits the shape of the seventh lens L7, and within the range of the condition, as the lens becomes thinner and wider angle-oriented, it is advantageous for correcting aberrations such as off-axis angle of view. Preferably, the condition -1.91 ≤ (R13 + R14) / (R13 - R14) ≤ -1.23 is satisfied.

[0054] If we define the axial thickness of the seventh lens L7 as d13 and the total optical length of the imaging optical lens 10 as TTL, then the condition 0.02 ≤ d13 / TTL ≤ 0.06 is satisfied. Within this range, it is advantageous for miniaturization. Preferably, the condition 0.02 ≤ d13 / TTL ≤ 0.05 is satisfied.

[0055] The field of view (FOV) of the aforementioned imaging optical lens is 197.00° or greater, thereby achieving a wide-angle view.

[0056] The aperture value FNO of the aforementioned imaging optical lens is 1.10 or less, which allows for a large aperture and superior imaging performance of the imaging optical lens.

[0057] The imaging optical lens of the present invention will be described below using examples. The reference numerals used in each example are as follows. The units for focal length, axial distance, central radius of curvature, and axial thickness are mm.

[0058] TTL: Total optical length (the on-axial distance from the side of the object on the first lens L1 to the image plane Si), in units of mm.

[0059] Aperture value Fno: This is the ratio of the effective focal length of the imaging optical lens to the diameter of the entrance pupil.

[0060] Next, the technical proposal of the present invention will be specifically described with respect to seven embodiments and one comparative embodiment.

[0061] (First Embodiment) Tables 1 and 2 show the design data for the imaging optical lens 10 according to the first embodiment of the present invention.

[0062] [Table 1]

[0063] However, the meaning of each symbol is as follows: S1: Aperture R: Radius of curvature at the center of the optical surface R1: Center radius of curvature of the object side of the first lens L1 in the paraxial direction. R2: Center radius of curvature in the paraxial direction of the image lateral surface of the first lens L1. R3: Center radius of curvature of the object side of the second lens L2 in the paraxial direction. R4: Center radius of curvature in the paraxial direction of the image lateral surface of the second lens L2. R5: Center radius of curvature of the object's side surface of the third lens L3 in the paraxial direction. R6: Center radius of curvature in the paraxial direction of the image lateral surface of the third lens L3. R7: Center radius of curvature of the object side of the fourth lens L4 in the paraxial direction. R8: Center radius of curvature in the paraxial direction of the image lateral surface of the fourth lens L4. R9: Center radius of curvature of the object's side surface of the fifth lens L5 in the paraxial direction. R10: Center radius of curvature in the paraxial direction of the image lateral surface of the fifth lens L5. R11: Center radius of curvature of the object's side surface of lens L6 (6th lens) in the paraxial direction. R12: Center radius of curvature in the paraxial direction of the image lateral surface of the sixth lens L6. R13: Center radius of curvature of the object side of lens L7 in the paraxial direction. R14: Center radius of curvature in the paraxial direction of the image lateral surface of lens L7 (7th lens). R15: Center radius of curvature of the paraxial side of the object surface of the optical filter GF R16: Center radius of curvature in the paraxial direction of the image side of the optical filter GF d: Axial thickness of the lens, axial distance between lenses d0: Axial distance from aperture S1 to the side of the object on the first lens L1. d1: Axial thickness of the first lens L1 d2: On-axis distance from the image side of the first lens L1 to the object side of the second lens L2. d3: Axial thickness of the second lens L2 d4: On-axis distance from the image side of the second lens L2 to the object side of the third lens L3. d5: Axial thickness of the third lens L3 d6: On-axis distance from the image side of the third lens L3 to the object side of the fourth lens L4. d7: Axial thickness of the fourth lens L4 d8: On-axis distance from the image side of the fourth lens L4 to the object side of the fifth lens L5. d9: Axial thickness of the 5th lens L5 d10: On-axis distance from the image side of the 5th lens L5 to the object side of the 6th lens L6. d11: Axial thickness of the 6th lens L6 d12: On-axis distance from the image side of lens 6 L6 to the object side of lens 7 L7. d13: Axial thickness of lens L7 (7th lens) d14: On-axis distance from the image side of lens L7 to the object side of optical filter GF d15: On-axis thickness of optical filter GF d16: On-axis distance from the image side of the optical filter GF to the image plane Si. nd: Refractive index of the d-line (the 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 lens L4 (4th lens) nd5: Refractive index of the d line of lens L5 (5th lens) nd6: Refractive index of the d line of lens L6 (6th lens) nd7: Refractive index of the d line of lens L7 (7th lens) ndg: Refractive index of the d line in 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 lens L5 (5th lens) v6: Abbe number of lens L6 (6th lens) v7: Abbe number of lens L7 (7th lens) vg: Abbe number of optical filter GF

[0064] Table 2 shows the aspherical data of each lens in the imaging optical lens 10 according to the first embodiment of the present invention.

[0065] [Table 2]

[0066] For convenience, the aspherical surface of each lens surface is represented by the aspherical surface shown in equation (22) below. However, the present invention is not particularly limited to this aspherical polynomial of equation (22).

[0067]

number

[0068] However, k is the conicity coefficient, A4, A6, A8, A10, A12, A14, A16, A18, and A20 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 at a distance of r from the optical axis and the cross section tangent to the vertex on the optical axis of the aspheric surface).

[0069] Figures 2 and 3 are schematic diagrams showing the axial aberration and lateral chromatic aberration after light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm passes through the imaging optical lens 10 according to the first embodiment, respectively. Figure 4 is a schematic diagram showing the field curvature and distortion after light with a wavelength of 555 nm passes through the imaging optical lens 10 according to the first embodiment, where the field curvature S in Figure 4 is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0070] In this embodiment, the entrance pupil diameter (ENPD) of the imaging optical lens 10 is 0.628 mm, the image height (IH) of the entire field of view (1.0x field of view) is 1.088 mm, and the angle of view (FOV) in the diagonal direction of the entire field of view (1.0x field of view) is 197.00°. The imaging optical lens 10 satisfies the design requirements of large aperture, wide angle, and ultra-thinness, and its on-axial and off-axial chromatic aberrations are sufficiently corrected, resulting in excellent optical characteristics.

[0071] To make it easier to understand, the image height in a 1.0x field of view refers to half the length of the diagonal of the sensor's effective pixel area, and the diagonal FOV in a 1.0x field of view refers to the field of view corresponding to the sensor's effective pixel area.

[0072] (Second Embodiment) The meaning of the reference numerals in the second embodiment is the same as in the first embodiment.

[0073] Figure 5 shows an imaging optical lens 20 according to a second embodiment of the present invention.

[0074] Tables 3 and 4 show the design data for the imaging optical lens 20 according to the second embodiment of the present invention.

[0075] [Table 3]

[0076] Table 4 shows the aspherical data of each lens in the imaging optical lens 20 according to the second embodiment of the present invention.

[0077] [Table 4]

[0078] Figures 6 and 7 are schematic diagrams showing the axial aberration and lateral chromatic aberration after light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm passes through the imaging optical lens 20 according to the second embodiment, respectively. Figure 8 is a schematic diagram showing the field curvature and distortion after light with a wavelength of 555 nm passes 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 tangential direction.

[0079] In this embodiment, the entrance pupil diameter (ENPD) of the imaging optical lens 20 is 0.549 mm, the image height (IH) of the entire field of view (1.0x field of view) is 1.044 mm, and the diagonal field of view (FOV) of the entire field of view (1.0x field of view) is 199.03°. The imaging optical lens 20 satisfies the design requirements of large aperture, wide angle, and ultra-thinness, and its on-axial and off-axial chromatic aberrations are sufficiently corrected, resulting in excellent optical characteristics.

[0080] (Third embodiment) The meaning of the reference numerals in the third embodiment is the same as in the first embodiment.

[0081] Figure 9 shows an imaging optical lens 30 according to the third embodiment of the present invention.

[0082] Tables 5 and 6 show the design data for the imaging optical lens 30 according to the third embodiment of the present invention.

[0083] [Table 5]

[0084] Table 6 shows the aspherical data for each lens in the imaging optical lens 30 according to the third embodiment of the present invention.

[0085] [Table 6]

[0086] Figures 10 and 11 are schematic diagrams showing the axial aberration and lateral chromatic aberration after light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm passes through the imaging optical lens 30 according to the third embodiment, respectively. Figure 12 is a schematic diagram showing the field curvature and distortion after light with a wavelength of 555 nm passes through the imaging optical lens 30 according to the third embodiment. In Figure 12, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0087] In this embodiment, the entrance pupil diameter (ENPD) of the imaging optical lens 30 is 0.599 mm, the image height (IH) of the entire field of view (1.0x field of view) is 1.029 mm, and the angle of view (FOV) in the diagonal direction of the entire field of view (1.0x field of view) is 197.10°. The imaging optical lens 30 satisfies the design requirements of large aperture, wide angle, and ultra-thinness, and its on-axial and off-axial chromatic aberrations are sufficiently corrected, resulting in excellent optical characteristics.

[0088] (Fourth Embodiment) The meaning of the reference numerals in the fourth embodiment is the same as in the first embodiment.

[0089] Figure 13 shows an imaging optical lens 40 according to the fourth embodiment of the present invention.

[0090] Tables 7 and 8 show the design data for the imaging optical lens 40 according to the fourth embodiment of the present invention.

[0091] [Table 7]

[0092] Table 8 shows the aspherical data for each lens in the imaging optical lens 40 according to the fourth embodiment of the present invention.

[0093] [Table 8]

[0094] Figures 14 and 15 are schematic diagrams showing the axial aberration and lateral chromatic aberration after light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm passes through the imaging optical lens 40 according to the fourth embodiment, respectively. Figure 16 is a schematic diagram showing the field curvature and distortion after light with a wavelength of 555 nm passes through the imaging optical lens 40 according to the fourth embodiment. In Figure 16, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0095] In this embodiment, the entrance pupil diameter (ENPD) of the imaging optical lens 40 is 0.496 mm, the image height (IH) of the entire field of view (1.0x field of view) is 1.057 mm, and the diagonal field of view (FOV) of the entire field of view (1.0x field of view) is 196.86°. The imaging optical lens 40 satisfies the design requirements of large aperture, wide angle, and ultra-thinness, and its on-axial and off-axial chromatic aberrations are sufficiently corrected, resulting in excellent optical characteristics.

[0096] (Fifth embodiment) The meaning of the reference numerals in the fifth embodiment is the same as in the first embodiment.

[0097] Figure 17 shows an imaging optical lens 50 according to the fifth embodiment of the present invention.

[0098] Tables 9 and 10 show the design data for the imaging optical lens 50 according to the fifth embodiment of the present invention.

[0099] [Table 9]

[0100] Table 10 shows the aspherical data of each lens in the imaging optical lens 50 according to the fifth embodiment of the present invention.

[0101] [Table 10]

[0102] Figures 18 and 19 are schematic diagrams showing the axial aberration and lateral chromatic aberration after light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm passes through the imaging optical lens 50 according to the fifth embodiment, respectively. Figure 20 is a schematic diagram showing the field curvature and distortion after light with a wavelength of 555 nm passes through the imaging optical lens 50 according to the fifth embodiment. In Figure 20, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0103] In this embodiment, the entrance pupil diameter (ENPD) of the imaging optical lens 50 is 0.544 mm, the image height (IH) of the entire field of view (1.0x field of view) is 1.053 mm, and the diagonal field of view (FOV) of the entire field of view (1.0x field of view) is 199.20°. The imaging optical lens 50 satisfies the design requirements of large aperture, wide angle, and ultra-thinness, and its on-axial and off-axial chromatic aberrations are sufficiently corrected, resulting in excellent optical characteristics.

[0104] (Sixth Embodiment) The meaning of the reference numerals in the sixth embodiment is the same as in the first embodiment.

[0105] Figure 21 shows an imaging optical lens 60 according to the sixth embodiment of the present invention.

[0106] Tables 11 and 12 show the design data for the imaging optical lens 60 according to the sixth embodiment of the present invention.

[0107] [Table 11]

[0108] Table 12 shows the aspherical data for each lens in the imaging optical lens 60 according to the sixth embodiment of the present invention.

[0109] [Table 12]

[0110] Figures 22 and 23 are schematic diagrams showing the axial aberration and lateral chromatic aberration after light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm passes through the imaging optical lens 60 according to the sixth embodiment, respectively. Figure 24 is a schematic diagram showing the field curvature and distortion after light with a wavelength of 555 nm passes through the imaging optical lens 60 according to the sixth embodiment. In Figure 24, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0111] In this embodiment, the entrance pupil diameter (ENPD) of the imaging optical lens 60 is 0.686 mm, the image height (IH) of the entire field of view (1.0x field of view) is 1.052 mm, and the diagonal field of view (FOV) of the entire field of view (1.0x field of view) is 198.00°. The imaging optical lens 60 satisfies the design requirements of large aperture, wide angle, and ultra-thinness, and its on-axial and off-axial chromatic aberrations are sufficiently corrected, resulting in excellent optical characteristics.

[0112] (Seventh Embodiment) The meaning of the reference numerals in the seventh embodiment is the same as in the first embodiment.

[0113] Figure 25 shows an imaging optical lens 70 according to the seventh embodiment of the present invention.

[0114] Tables 13 and 14 show the design data for the imaging optical lens 70 according to the seventh embodiment of the present invention.

[0115] [Table 13]

[0116] Table 14 shows the aspherical data of each lens in the imaging optical lens 70 according to the seventh embodiment of the present invention.

[0117] [Table 14]

[0118] Figures 26 and 27 are schematic diagrams showing the axial aberration and lateral chromatic aberration after light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm passes through the imaging optical lens 70 according to the seventh embodiment, respectively. Figure 28 is a schematic diagram showing the field curvature and distortion after light with a wavelength of 555 nm passes through the imaging optical lens 70 according to the seventh embodiment. In Figure 28, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0119] In this embodiment, the entrance pupil diameter (ENPD) of the imaging optical lens 70 is 0.618 mm, the image height (IH) of the entire field of view (1.0x field of view) is 1.016 mm, and the diagonal field of view (FOV) of the entire field of view (1.0x field of view) is 197.00°. The imaging optical lens 70 satisfies the design requirements of large aperture, wide angle, and ultra-thinness, and its on-axial and off-axial chromatic aberrations are sufficiently corrected, resulting in excellent optical characteristics.

[0120] (Comparative Implementation) The meaning of the reference numerals in the comparative embodiment is the same as in the first embodiment.

[0121] Figure 29 shows an imaging optical lens 80 according to a comparative embodiment of the present invention.

[0122] Tables 15 and 16 show the design data for the imaging optical lens 80 according to a comparative embodiment of the present invention.

[0123] [Table 15]

[0124] Table 16 shows the aspherical data for each lens in the imaging optical lens 80 according to a comparative embodiment of the present invention.

[0125] [Table 16]

[0126] Figures 30 and 31 are schematic diagrams showing the axial aberration and lateral chromatic aberration after light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm passes through the imaging optical lens 80 according to the comparative embodiment, respectively. Figure 32 is a schematic diagram showing the field curvature and distortion after light with a wavelength of 555 nm passes through the imaging optical lens 80 according to the comparative embodiment. In Figure 32, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0127] In this embodiment, the entrance pupil diameter (ENPD) of the imaging optical lens 80 is 0.600 mm, the image height (IH) of the entire field of view (1.0x field of view) is 1.050 mm, the diagonal field of view (FOV) of the entire field of view (1.0x field of view) is 188.69°, and in the imaging optical lens 80, R5 / R6 = 1.47, which does not satisfy the condition 0.90 ≤ R5 / R6 ≤ 1.40. As a result, the design requirements for a large aperture, wide angle, and ultra-thin design cannot be met, and on-axial and off-axial chromatic aberration are not sufficiently corrected, resulting in a lack of excellent optical characteristics.

[0128] [Table 17]

[0129] As those skilled in the art will see, the above embodiments are specific embodiments for realizing the present invention, and in actual applications, various modifications to the form and details are possible as long as they do not deviate from the gist and scope of the present invention.

Claims

1. It is an imaging optical lens, The imaging optical lens is composed of a total of seven lenses, which, in order from the object side to the image side, are a first lens with negative refractive power, a second lens with negative refractive power, a third lens with refractive power, a fourth lens with positive refractive power, a fifth lens with positive refractive power, a sixth lens with positive refractive power, and a seventh lens with negative refractive power. An imaging optical lens characterized in that the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the central radius of curvature of the third lens in the paraxial direction of the object side surface is R5, the central radius of curvature of the third lens in the paraxial direction of the image side surface is R6, the angle of view of the imaging optical lens at 1.0x field of view is FOV, the aperture value of the imaging optical lens is Fno, and the following conditions (1) to (3) are satisfied. 1.50 ≤ f4 / f5 ≤ 3.40 (1) 0.90 ≤ R5 / R6 ≤ 1.40 (2) 170.00 ≤ FOV / Fno ≤ 200.00 (3)

2. The imaging optical lens according to claim 1, characterized in that the Abbe number of the sixth lens is ν6, the Abbe number of the seventh lens is ν7, and the following condition (4) is satisfied. v6-v7≧35.00 (4)

3. The imaging optical lens according to claim 1, characterized in that the on-axial distance from the image side of the seventh lens to the image plane is BF, the total optical length of the imaging optical lens is TTL, and the following condition (5) is satisfied. 0.09 ≤ BF / TTL ≤ 0.15 (5)

4. The imaging optical lens according to claim 1, characterized in that the focal length of the second lens is f2, the on-axial thickness of the second lens is d3, and the following condition (6) is satisfied. 8.80≦|f2 / d3|≦13.00 (6)

5. The first lens has an object side surface that is convex in the paraxial direction and an image side surface that is concave in the paraxial direction. The imaging optical lens according to claim 1, wherein the focal length of the imaging optical lens is f, the focal length of the first lens is f1, the central radius of curvature of the first lens in the paraxial direction of the object side surface is R1, the central radius of curvature of the first lens in the paraxial direction of the image side surface is R2, the on-axial thickness of the first lens is d1, the total optical length of the imaging optical lens is TTL, and the following conditions (7) to (9) are satisfied. -13.18 ≤ f1 / f ≤ -3.84 (7) 0.75≦(R1+R2) / (R1-R2)≦2.64 (8) 0.02 ≤ d1 / TTL ≤ 0.24 (9)

6. The second lens has an object side that is concave in the paraxial direction, and an image side that is concave in the paraxial direction. The imaging optical lens according to claim 1, characterized in that the focal length of the imaging optical lens is f, the focal length of the second lens is f2, the central radius of curvature of the second lens in the paraxial direction of the object side surface is R3, the central radius of curvature of the second lens in the paraxial direction of the image side surface is R4, the on-axial thickness of the second lens is d3, the total optical length of the imaging optical lens is TTL, and the following conditions (10) to (12) are satisfied. -7.57 ≤ f² / f ≤ -2.15 (10) 0.21≦(R3+R4) / (R3-R4)≦0.74 (11) 0.01 ≤ d3 / TTL ≤ 0.04 (12)

7. The third lens has an object side surface that is concave in the paraxial direction and an image side surface that is convex in the paraxial direction. The imaging optical lens according to claim 1, characterized in that the focal length of the imaging optical lens is f, the focal length of the third lens is f3, the on-axial thickness of the third lens is d5, the total optical length of the imaging optical lens is TTL, and the following conditions (13) to (15) are satisfied. -3743.34 ≤ f³ / f ≤ 88.10 (13) -39.92≦(R5+R6) / (R5-R6)≦18.19 (14) 0.07 ≤ d5 / TTL ≤ 0.25 (15)

8. The fourth lens has an object side surface that is concave in the paraxial direction and an image side surface that is convex in the paraxial direction. The imaging optical lens according to claim 1, wherein the focal length of the imaging optical lens is f, the central radius of curvature of the fourth lens in the paraxial direction of the object side surface is R7, the central radius of curvature of the fourth lens in the paraxial direction of the image side surface is R8, the on-axial thickness of the fourth lens is d7, the total optical length of the imaging optical lens is TTL, and the following conditions (16) to (18) are satisfied. 2.45 ≤ f₄ / f ≤ 14.08 (16) 0.72≦(R7+R8) / (R7-R8)≦3.62 (17) 0.03 ≤ d7 / TTL ≤ 0.15 (18)

9. The fifth lens has an object side surface that is convex in the paraxial direction, and an image side surface that is convex in the paraxial direction. The imaging optical lens according to claim 1, characterized in that the focal length of the imaging optical lens is f, the central radius of curvature of the fifth lens in the paraxial direction of the object side surface is R9, the central radius of curvature of the fifth lens in the paraxial direction of the image side surface is R10, the on-axial thickness of the fifth lens is d9, the total optical length of the imaging optical lens is TTL, and the following conditions (19) to (21) are satisfied. 1.29 ≤ f5 / f ≤ 4.85 (19) 0.03≦(R9+R10) / (R9-R10)≦0.33 (20) 0.04 ≤ d9 / TTL ≤ 0.19 (21)

10. The imaging optical lens according to claim 1, characterized in that the first lens is made of glass.

Images