Image capturing optical lens
The seven-lens optical lens design addresses the need for compact, wide-angle lenses with aberration correction, achieving superior imaging quality for mobile and vehicle applications.
Patent Information
- Application Number
- JP2024113602
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-04-19
- Filing Date
- 2024-07-16
- Publication Date
- 2025-10-30
- Estimated Expiration
- 2044-07-16
AI Technical Summary
There is a demand for imaging optical lenses that provide excellent optical performance, are compact, have a wide angle, and effectively correct aberrations, while meeting the design requirements of miniaturization and high functionality in modern electronic devices.
The imaging optical lens is composed of seven lenses, including an aperture stop and lenses with specific refractive powers and surface configurations, adhering to conditional expressions that optimize optical performance, such as -18.000≦f1/f+f2/f+f3/f≦-8.000 and -1.800≦f4/f+f5/f+f6/f+f7/f≦-0.600, to achieve wide angles and aberration correction.
The lens design achieves excellent optical performance, compactness, and wide angle with sufficient aberration correction, suitable for imaging assemblies in mobile phones and vehicles, enhancing imaging quality with high-pixel CCDs and CMOSs.
Smart Images
Figure 2025164649000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to the field of optical lenses, and more particularly to an imaging optical lens that is applied to mobile terminal devices such as smartphones and digital cameras, and imaging devices such as monitors, PC lenses, and in-vehicle lenses. [Background technology]
[0002] In recent years, with the development of various smart devices, the demand for miniaturized imaging optical lenses has been increasing. Furthermore, in addition to the shrinking pixel size of photosensitive elements, current electronic products are trending toward high functionality and lightweight, thin, and portable designs. Therefore, miniaturized imaging optical lenses with good imaging quality have become mainstream in the current market. To achieve good imaging quality, multi-lens structures are often adopted. Furthermore, with technological developments and the increasing diversification of user needs, the pixel area of photosensitive elements is shrinking, and the system requirements for imaging quality are increasing. Therefore, seven-lens structures are gradually appearing in lens designs. There is a demand for optical imaging lenses with excellent optical performance, miniaturization, a wide angle, and sufficient aberration correction. 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 excellent optical performance, is compact, has a wide angle, and satisfies design requirements such as sufficient correction of aberrations. [Means for solving the problem]
[0004] To achieve the above object, the solution of the present invention provides an imaging optical lens, which is composed of an aperture stop and seven lenses, which are, 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 positive refractive power, a fifth lens having negative refractive power, a sixth lens having positive refractive power, and a seventh lens having negative refractive power; the first lens has an object-side surface that is convex at the paraxial line and an image-side surface that is concave at the paraxial line, the second lens has an object-side surface that is convex at the paraxial line and an image-side surface that is concave at the paraxial line, the third lens has an object-side surface that is concave at the paraxial line and an image-side surface that is concave at the paraxial line, the fourth lens has an object-side surface that is convex at the paraxial line, the fifth lens has an object-side surface that is convex at the paraxial line and an image-side surface that is concave at the paraxial line, the sixth lens has an object-side surface that is convex at the paraxial line and an image-side surface that is convex at the paraxial line, and the seventh lens has an object-side surface that is convex at the paraxial line and an image-side surface that is concave at the paraxial line, When a focal length of the imaging optical lens is f, a focal length of the first lens is f1, a focal length of the second lens is f2, a focal length of the third lens is f3, a focal length of the fourth lens is f4, a focal length of the fifth lens is f5, a focal length of the sixth lens is f6, a focal length of the seventh lens is f7, an axial distance from the aperture stop to the object-side surface of the first lens is d0, an axial thickness of the first lens is d1, a paraxial central radius of curvature of the object-side surface of the fifth lens is R9, a paraxial central radius of curvature of the image-side surface of the fifth lens is R10, a paraxial central radius of curvature of the image-side surface of the fifth lens is R12, a paraxial central radius of curvature of the object-side surface of the seventh lens is R13, and a paraxial central radius of curvature of the image-side surface of the seventh lens is R14, the following conditional expressions (1) to (7) are satisfied. -18.000≦f1 / f+f2 / f+f3 / f≦-8.000 (1) -1.800≦f4 / f+f5 / f+f6 / f+f7 / f≦-0.600 (2) -0.080≦d0 / d1≦-0.050 (3) -8.000≦R12 / f6≦-2.500 (4) -1.000≦f4 / f5≦-0.500 (5) 1.700≦(R9+R10) / f≦2.600 (6) 2.000≦R13 / R14≦6.000 (7)
[0005] Preferably, the following conditional expression (8) is satisfied. -15.000≦f1 / f+f2 / f+f3 / f≦-9.000 (8)
[0006] Preferably, the following conditional expression (9) is satisfied. -1.500≦f4 / f+f5 / f+f6 / f+f7 / f≦-0.700 (9)
[0007] Preferably, when the axial distance between the image-side surface of the fourth lens and the object-side surface of the fifth lens is d8 and the optical length of the imaging optical lens is TTL, the following conditional expression (10) is satisfied. 0.065≦d8 / TTL≦0.120 (10)
[0008] Preferably, the first lens is made of a glass material.
[0009] To achieve the above object, the present invention also provides an imaging optical lens, which is composed of an aperture stop and seven lenses, which are, 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 positive refractive power, a fifth lens having negative refractive power, a sixth lens having positive refractive power, and a seventh lens having negative refractive power; the first lens has an object-side surface that is convex at the paraxial line and an image-side surface that is concave at the paraxial line, the second lens has an object-side surface that is convex at the paraxial line and an image-side surface that is concave at the paraxial line, the third lens has an object-side surface that is concave at the paraxial line and an image-side surface that is concave at the paraxial line, the fourth lens has an object-side surface that is convex at the paraxial line, the fifth lens has an object-side surface that is convex at the paraxial line and an image-side surface that is concave at the paraxial line, the sixth lens has an object-side surface that is convex at the paraxial line and an image-side surface that is convex at the paraxial line, and the seventh lens has an object-side surface that is convex at the paraxial line and an image-side surface that is concave at the paraxial line, where f is the focal length of the imaging optical lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, d0 is the axial distance from the aperture stop to the object-side surface of the first lens, d1 is the axial thickness of the first lens, and R1 is the central radius of curvature of the object-side surface of the first lens on the paraxial line. When the central radius of curvature of the image side surface of the first lens in the paraxial direction is R2, the central radius of curvature of the object side surface of the seventh lens in the paraxial direction is R13, the central radius of curvature of the image side surface of the seventh lens in the paraxial direction is R14, the sum of the axial thicknesses of the first lens to the seventh lens is Σd, and the sum of the axial lengths of the air gaps between any two adjacent lenses among the first lens to the seventh lens is ΣD, the following conditional expressions (1) to (3) and (11) to (13) are satisfied. -18.000≦f1 / f+f2 / f+f3 / f≦-8.000 (1) -1.800≦f4 / f+f5 / f+f6 / f+f7 / f≦-0.600 (2) -0.080≦d0 / d1≦-0.050 (3) 2.600≦f1 / R1+f1 / R2≦4.800 (11) 0.600≦(R13+R14) / f≦2.600 (12) 0.600≦ΣD / Σd≦0.950 (13)
[0010] Preferably, the following conditional expression (8) is satisfied. -15.000≦f1 / f+f2 / f+f3 / f≦-9.000 (8)
[0011] Preferably, the following conditional expression (9) is satisfied. -1.500≦f4 / f+f5 / f+f6 / f+f7 / f≦-0.700 (9)
[0012] Preferably, the following conditional expression (14) is satisfied. 3.400≦f1 / R1+f1 / R2≦4.000 (14)
[0013] Preferably, the following conditional expression (15) is satisfied. 0.700≦(R13+R14) / f≦2.200 (15)
[0014] Preferably, the following conditional expression (16) is satisfied. 0.630≦ΣD / Σd≦0.920 (16)
[0015] Preferably, when a composite focal length of the first lens and the second lens is f12 and a central radius of curvature of the image side surface of the second lens on the paraxial line is R4, the following conditional expression (17) is satisfied. -3.000≦f12 / (R1-R4)≦-1.300 (17)
[0016] Preferably, the following conditional expression (18) is satisfied. -2.600≦f12 / (R1-R4)≦-1.500 (18)
[0017] Preferably, the following conditional expression (19) is satisfied. 0.007≦d0 / (R1-R2)≦0.020 (19)
[0018] Preferably, the following conditional expression (20) is satisfied. 0.008≦d0 / (R1-R2)≦0.018 (20)
[0019] Preferably, the first lens is made of a glass material. [Effects of the Invention]
[0020] The beneficial effects of the present invention are as follows: The imaging optical lens according to the present invention has excellent optical performance, is compact, has a wide angle of view, and has the characteristics of sufficiently correcting aberrations, and is particularly applicable to imaging lens assemblies for mobile phones, web imaging lenses, and vehicle-mounted lenses, which are configured with imaging elements such as high-pixel CCDs and CMOSs.
[0021] In order to more clearly explain the technical solution of the imaging optical lens of the present invention, the drawings necessary for the embodiments are briefly introduced below. Note that the drawings described below illustrate some embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without any creative work. [Brief explanation of the drawings]
[0022] [Figure 1] 1 is a schematic diagram showing the configuration of an imaging optical lens according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of axial chromatic aberration of the imaging optical lens shown in FIG. [Figure 3] FIG. 2 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 4] 2A to 2C are schematic diagrams of field curvature and distortion of the imaging optical lens shown in FIG. [Figure 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] FIG. 6 is a schematic diagram of axial chromatic aberration of the imaging optical lens shown in FIG. [Figure 7] FIG. 6 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in FIG. 5. [Figure 8] 6A and 6B are schematic diagrams of field curvature and distortion of the imaging optical lens shown in FIG. 5. [Figure 9] FIG. 10 is a schematic diagram showing the configuration of an imaging optical lens according to a third embodiment of the present invention. [Figure 10] FIG. 10 is a schematic diagram of axial chromatic aberration of the imaging optical lens shown in FIG. [Figure 11] FIG. 10 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 12] 10A and 10B are schematic diagrams of field curvature and distortion of the imaging optical lens shown in FIG. [Figure 13] FIG. 10 is a schematic diagram showing the configuration of an imaging optical lens according to a fourth embodiment of the present invention. [Figure 14] FIG. 14 is a schematic diagram of axial chromatic aberration of the imaging optical lens shown in FIG. [Figure 15] FIG. 14 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 16] 14A to 14C are schematic diagrams of field curvature and distortion of the imaging optical lens shown in FIG. 13. DETAILED DESCRIPTION OF THE INVENTION
[0023] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following detailed description of the embodiments of the present invention will be given with reference to the drawings. Those skilled in the art will understand that many technical details are mentioned in the embodiments of the present invention to better understand the present invention. However, the technical solutions claimed by the present invention can be realized without these technical details and various changes and modifications based on the following embodiments.
[0024] As shown in Figures 1 to 16, the technical solution of the present invention provides imaging optical lenses 10, 20, 30, and 40. Figures 1, 5, 9, and 13 respectively show imaging optical lenses 10, 20, 30, and 40 according to the present invention, and the imaging optical lenses 10, 20, 30, and 40 include a total of seven lenses. Specifically, the imaging optical lenses include, in order from the object side to the image side, an aperture stop S1, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7. An optical element such as an optical filter GF may be provided between the seventh lens L7 and the image plane Si.
[0025] 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, although each lens may be made of other materials.
[0026] The object-side and image-side surfaces of the first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6 and seventh lens L7 are all aspheric.
[0027] The refractive powers of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are positive, negative, negative, positive, negative, positive, negative, respectively. The object side surface of the first lens L1 is a convex surface paraxially and the image side surface is a concave surface paraxially. The object side surface of the second lens L2 is a convex surface paraxially and the image side surface is a concave surface paraxially. The third lens L3 is a concave surface paraxially and the object side surface of the image side The fourth lens L4 has a convex object side surface paraxially and the image side surface may be either convex or concave paraxially, the fifth lens L5 has a convex object side surface paraxially and a concave image side surface paraxially, the sixth lens L6 has a convex object side surface paraxially and a convex image side surface paraxially, and the seventh lens L7 has a convex object side surface paraxially and a concave image side surface paraxially.
[0028] If we define the focal length of the imaging optical lens as f, the focal length of the first lens L1 as f1, the focal length of the second lens L2 as f2, and the focal length of the third lens L3 as f3, then the conditional expression -18,000≦f1 / f+f2 / f+f3 / f≦-8,000 is satisfied. Rational control of the refractive power of the front three lenses within this range is beneficial for expanding and widening the angle of view. Furthermore, the conditional expression -15,000≦f1 / f+f2 / f+f3 / f≦-9,000 is satisfied.
[0029] If the focal length of the fourth lens L4 is defined as f4, the focal length of the fifth lens L5 as f5, the focal length of the sixth lens L6 as f6, and the focal length of the seventh lens L7 as f7, then the conditional expression -1.800≦f4 / f+f5 / f+f6 / f+f7 / f≦-0.600 is satisfied. Rational control of the refractive powers of the rear four lenses within this range is advantageous for correcting aberrations and shortening the optical length. Furthermore, the conditional expression -1.500≦f4 / f+f5 / f+f6 / f+f7 / f≦-0.700 is satisfied.
[0030] If the axial distance from the aperture stop S1 to the object-side surface of the first lens L1 is defined as d0 (if the point on the optical axis of the object-side surface of the first lens L1 is closer to the object than the center of the aperture stop S1, d0 is a negative value, and if the point on the optical axis of the object-side surface of the first lens L1 is closer to the image than the center of the aperture stop S1, d0 is a positive value), and the axial thickness of the first lens L1 is defined as d1, then the conditional expression -0.080≦d0 / d1≦-0.050 is satisfied. By rationally controlling the position of the aperture stop and the axial thickness of the first lens within this range, the imaging optical lens can have a high amount of light entering and the object-side surface of the first lens can have a reasonable thickness, which is advantageous for improving yields.
[0031] If the central radius of curvature of the image-side surface of sixth lens L6 at the paraxial line is defined as R12 and the focal length of sixth lens L6 is defined as f6, the conditional expression -8.000≦R12 / f6≦−2.500 is satisfied. Within this range, the effect of astigmatism on the imaging optical lens can be improved, thereby improving the imaging quality of the imaging optical lens.
[0032] If the focal length of the fourth lens L4 is defined as f4 and the focal length of the fifth lens L5 as f5, then the conditional expression -1.000≦f4 / f5≦-0.500 is satisfied. Within this range, an appropriate refractive power can be assigned to the fifth lens to correct the aberrations generated by the fourth lens, which contributes to improving peripheral imaging quality.
[0033] If the central radius of curvature of the object-side surface of fifth lens L5 at the paraxial direction is defined as R9, the central radius of curvature of the image-side surface of fifth lens L5 at the paraxial direction is defined as R10, and the focal length of the imaging optical lens is defined as f, then the conditional expression 1.700≦(R9+R10) / f≦2.600 is satisfied. Within this range, the refractive power of the fifth lens can be easily adjusted, and the fifth lens can easily correct the axial chromatic aberration and off-axial chromatic aberration of magnification after light rays pass through the fourth lens, thereby improving imaging quality.
[0034] If the central radius of curvature of the object-side surface of seventh lens L7 at the paraxial line is defined as R13 and the central radius of curvature of the image-side surface of seventh lens L7 at the paraxial line is defined as R14, then the conditional expression 2.000≦R13 / R14≦6.000 is satisfied. By controlling the ratio between the central radius of curvature of the object-side surface of seventh lens L7 at the paraxial line and the central radius of curvature of the image-side surface of seventh lens L7 at the paraxial line within this range, it is possible to ensure the ease of fabricating the seventh lens, reduce system aberrations, and improve imaging quality.
[0035] If the axial distance between the image-side surface of the fourth lens L4 and the object-side surface of the fifth lens L5 is defined as d8, and the optical length of the imaging optical lens is defined as TTL, then the conditional expression 0.065≦d8 / TTL≦0.120 is satisfied. This range is advantageous for shortening the optical length of the imaging optical lens.
[0036] If we define the central radius of curvature of the object-side surface of first lens L1 on the paraxial line as R1, the central radius of curvature of the image-side surface of first lens L1 on the paraxial line as R2, and the focal length of first lens L1 as f1, then the conditional expression 2.600≦f1 / R1+f1 / R2≦4.800 is satisfied. Within this range, the surface shape and refractive power of the first lens can be adjusted, contributing to volume compression and an increase in the field of view. Furthermore, the conditional expression 3.400≦f1 / R1+f1 / R2≦4.000 is satisfied.
[0037] If the central radius of curvature of the object-side surface of the seventh lens L7 at the paraxial direction is defined as R13, the central radius of curvature of the image-side surface of the seventh lens L7 at the paraxial direction is defined as R14, and the focal length of the imaging optical lens is defined as f, then the conditional expression 0.600≦(R13+R14) / f≦2.600 is satisfied. By appropriately controlling the relationship between the central radius of curvature of the seventh lens L7 at the paraxial direction and the focal length within this range, the seventh lens L7 can more effectively correct aberrations, which is advantageous for improving the imaging quality of the imaging optical lens. Furthermore, the conditional expression 0.700≦(R13+R14) / f≦2.200 is satisfied.
[0038] If we define the sum of the axial thicknesses of the first lens L1 through the seventh lens L7 as Σd and the sum of the axial lengths of the air gaps between any two adjacent lenses among the first lens L1 through the seventh lens L7 as ΣD, then the conditional expression 0.600≦ΣD / Σd≦0.950 is satisfied. Rational control of the air gaps between adjacent lenses and the axial thickness of each lens within this range is advantageous for shortening the optical length and achieving an extremely thin design. Furthermore, the conditional expression 0.630≦ΣD / Σd≦0.920 is satisfied.
[0039] If the composite focal length of the first lens L1 and the second lens L2 is defined as f12 and the central radius of curvature of the paraxial image-side surface of the second lens L2 is defined as R4, the conditional expression -3.000≦f12 / (R1-R4)≦-1.300 is satisfied. By rationally arranging the composite focal length and surface shape of the first and second lenses within this range, chromatic aberration is eliminated, spherical aberration is reduced, astigmatism is corrected, and resolving power is improved. Furthermore, the conditional expression -2.600≦f12 / (R1-R4)≦-1.500 is satisfied.
[0040] If we define R1 as the central radius of curvature of the object-side surface of first lens L1 on the paraxial line, R2 as the central radius of curvature of the image-side surface of first lens L1 on the paraxial line, and d0 as the on-axis distance from the aperture stop to the object-side surface of the first lens, the conditional expression 0.007≦d0 / (R1-R2)≦0.020 is satisfied. Within this range, the aperture stop protrudes outward, providing more space for external installation of the stop, which is advantageous for the structural design of the variable stop. Furthermore, the conditional expression 0.008≦d0 / (R1-R2)≦0.018 is satisfied.
[0041] The first lens L1 is made of glass, and the combination of glass and resin lenses serves to reduce chromatic aberration and improve the performance of the optical imaging lens.
[0042] Compared to the prior art, the imaging optical lens according to the present invention has the following arrangements: -18,000≦f1 / f+f2 / f+f3 / f≦-8,000, -1.800≦f4 / f+f5 / f+f6 / f+f7 / f≦-0.600, -0.080≦d0 / d1≦-0.050, -8,000≦R12 / f6≦-2,500, -1.000≦f4 / f5≦-0.500, 1.700≦(R9+R10) / f≦2.600, 2.000≦R13 / R14≦6.000. This is advantageous for expanding and widening the angle of view and correcting aberrations. In addition, the imaging optical lens has a high amount of light incident on it, and the object-side surface of the first lens has a reasonable thickness, which is advantageous for improving yields. Furthermore, since it is advantageous in improving the effect of astigmatism on the imaging optical lens, the imaging quality of the imaging optical lens is improved, and by allocating an appropriate refractive power to the fifth lens, aberrations such as on-axis chromatic aberration and off-axis chromatic aberration of magnification can be corrected, contributing to improvement of peripheral imaging quality and ensuring the ease of processing the seventh lens.
[0043] Furthermore, compared to the prior art, the present invention has arrangements such that -18,000≦f1 / f+f2 / f+f3 / f≦-8,000, -1.800≦f4 / f+f5 / f+f6 / f+f7 / f≦-0.600, -0.080≦d0 / d1≦-0.050, 2.600≦f1 / R1+f1 / R2≦4.800, 0.600≦(R13+R14) / f≦2.600, and 0.600≦ΣD / Σd≦0.950. This is advantageous for expanding the angle of view, achieving a wider angle of view, and satisfying compactness, as well as for correcting aberrations. It also improves the imaging quality of the imaging optical lens, enables the imaging optical lens to have a high amount of light incident, and enables the object-side surface of the first lens to have a reasonable thickness, which is advantageous for improving yields.
[0044] The imaging optical lens of the present invention will be described below using examples. The symbols used in each example are as follows: The focal length, axial distance, central radius of curvature, and axial thickness are all in mm.
[0045] TTL is the optical length (the axial distance from the object side surface of the first lens L1 to the image plane Si) and is expressed in mm.
[0046] The aperture value FNO refers to the ratio of the effective focal length of an imaging optical lens to the entrance pupil diameter.
[0047] Next, the technical solution of the present invention will be specifically explained in four embodiments, but if the above conditional expressions are not satisfied, the technical effect of the present invention cannot be realized.
[0048] (First embodiment) Tables 1 and 2 show design data for the imaging optical lens 10 according to the first embodiment of the present invention.
[0049] [Table 1]
[0050] Here, the meaning of each symbol is as follows: S1: aperture stop, R: Radius of curvature at the center of the optical surface R1: central radius of curvature of the object side surface of the first lens L1 on the paraxial line R2: paraxial central radius of curvature of the image-side surface of the first lens L1 R3: The central radius of curvature of the object-side surface of the second lens L2 on the paraxial line R4: paraxial central curvature radius of the image-side surface of the second lens L2 R5: The central radius of curvature of the object-side surface of the third lens L3 on the paraxial line R6: paraxial central curvature radius of the image-side surface of the third lens L3 R7: The central radius of curvature of the object-side surface of the fourth lens L4 on the paraxial line R8: Paraxial central curvature radius of the image-side surface of the fourth lens L4 R9: The central radius of curvature of the object-side surface of the fifth lens L5 on the paraxial line R10: Paraxial central curvature radius of the image-side surface of the fifth lens L5 R11: The central radius of curvature of the object side surface of the sixth lens L6 on the paraxial line R12: Paraxial central curvature radius of the image-side surface of the sixth lens L6 R13: the central radius of curvature of the object side surface of the seventh lens L7 at the paraxial position, R14: Paraxial central curvature radius of the image-side surface of the seventh lens L7 R15: The central radius of curvature of the object-side surface of the optical filter GF on the paraxial line R16: Central radius of curvature of the image side of the optical filter GF on the paraxial line d: Axial thickness of lens, axial distance between lenses d0: On-axis distance from aperture stop S1 to the object side of first lens L1 d1: Axial thickness of the first lens L1 d2: On-axis 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 element 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 element L3 d6: On-axis 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 element 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 element 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 element L6 d12: the axial distance from the image side surface of the sixth lens L6 to the object side surface of the seventh lens L7 d13: Axial thickness of the seventh lens element L7 d14: The axial distance from the image side surface of the seventh lens L7 to the object side surface of the 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 (d line is green light with a wavelength of 550 nm) nd1: refractive index of the first lens L1 at the d line nd2: refractive index of the d line of the second lens L2 nd3: refractive index of the d line of the third lens L3 nd4: Refractive index of the d line of the fourth lens L4 nd5: refractive index of the d line of the fifth lens L5 nd6: Refractive index of the d line of the sixth lens L6 nd7: Refractive index of the d line of the seventh lens L7 ndg: refractive index of the d line of the optical filter GF vd: Abbe number v1: Abbe number of the first lens L1 v2: Abbe number of the second lens L2 v3: Abbe number of the third lens element L3 v4: Abbe number of the fourth lens element L4 v5: Abbe number of the fifth lens element L5 v6: Abbe number of the sixth lens element L6 v7: Abbe number of the seventh lens element L7 vg: Abbe number of the optical filter GF
[0051] Table 2 shows the aspheric surface data of each lens in the imaging optical lens 10 according to the first embodiment of the present invention.
[0052] [Table 2]
[0053] For convenience, the aspherical surface of each lens surface is expressed by the following formula (21): However, the present invention is not limited to the form of the aspherical polynomial shown in formula (21).
[0054] 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 one)
[0055] 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).
[0056] 2 and 3 are schematic diagrams showing the axial chromatic aberration and chromatic aberration of magnification of light with wavelengths of 656 nm, 588 nm, 546 nm, 486 nm, and 436 nm, respectively, after passing through the imaging optical lens 10 according to the first embodiment. Fig. 4 is a schematic diagram showing the curvature of field and distortion of light with a wavelength of 546 nm after passing through the imaging optical lens 10 according to the first embodiment, where the curvature of field S in Fig. 4 is the curvature of field in the sagittal direction and T is the curvature of field in the tangential direction.
[0057] In this embodiment, the entrance pupil diameter ENPD of the imaging optical lens 10 is 4.614 mm, the image height IH of the 1.0 field of view is 7.900 mm, the image height of the MIC field of view is 8.100 mm, the FOV in the diagonal direction of the 1.0 field of view is 86.60°, and the FOV in the diagonal direction of the MIC field of view is 88.18°. The imaging optical lens 10 satisfies the design requirements of being compact, having a wide angle, and having sufficient correction for aberrations, and has excellent optical characteristics.
[0058] As can be understood, the image height of the 1.0 field of view refers to half the diagonal length of the sensor's effective pixel area, the image height of the MIC field of view refers to the field of view height that extends outward from the image height of the 1.0 field of view to prevent assembly variations, the FOV in the diagonal direction of the 1.0 field of view refers to the angle of view corresponding to the sensor's effective pixel area, and the FOV in the diagonal direction of the MIC field of view refers to the angle of view corresponding to the image height of the MIC field of view.
[0059] (Second embodiment) The meanings of the symbols in the second embodiment are the same as those in the first embodiment.
[0060] FIG. 5 shows an imaging optical lens 20 according to a second embodiment of the present invention.
[0061] Tables 3 and 4 show design data for the imaging optical lens 20 according to the second embodiment of the present invention.
[0062] [Table 3]
[0063] Table 4 shows the aspheric data of each lens in the imaging optical lens 20 according to the second embodiment of the present invention.
[0064] [Table 4]
[0065] 6 and 7 are schematic diagrams showing the axial chromatic aberration and chromatic aberration of magnification of light having wavelengths of 656 nm, 588 nm, 546 nm, 486 nm, and 436 nm, respectively, after passing through the imaging optical lens 20 according to the second embodiment. Fig. 8 is a schematic diagram showing the curvature of field and distortion of light having a wavelength of 546 nm after passing through the imaging optical lens 20 according to the second embodiment. In Fig. 8, the curvature of field S is the curvature of field in the sagittal direction, and T is the curvature of field in the tangential direction.
[0066] In this embodiment, the entrance pupil diameter ENPD of the imaging optical lens 20 is 4.679 mm, the image height IH of the 1.0 field of view is 7.899 mm, the image height of the MIC field of view is 8.100 mm, the FOV in the diagonal direction of the 1.0 field of view is 86.90°, and the FOV in the diagonal direction of the MIC field of view is 88.42°, and the imaging optical lens 20 satisfies the design requirements of being compact, having a wide angle, and having sufficient correction for aberrations, and has excellent optical characteristics.
[0067] (Third embodiment) The meanings of the symbols in the third embodiment are the same as those in the first embodiment.
[0068] FIG. 9 shows an imaging optical lens 30 according to a third embodiment of the present invention.
[0069] Tables 5 and 6 show design data for the imaging optical lens 30 according to the third embodiment of the present invention.
[0070] [Table 5]
[0071] Table 6 shows the aspheric surface data of each lens in the imaging optical lens 30 according to the third embodiment of the present invention.
[0072] [Table 6]
[0073] 10 and 11 are schematic diagrams showing the axial chromatic aberration and chromatic aberration of magnification of light with wavelengths of 656 nm, 588 nm, 546 nm, 486 nm, and 436 nm, respectively, after passing through the imaging optical lens 30 according to the third embodiment. Fig. 12 is a schematic diagram showing the curvature of field and distortion of light with a wavelength of 546 nm after passing through the imaging optical lens 30 according to the third embodiment. In Fig. 12, the curvature of field S is the curvature of field in the sagittal direction, and T is the curvature of field in the tangential direction.
[0074] In this embodiment, the entrance pupil diameter ENPD of the imaging optical lens 30 is 4.885 mm, the image height IH of the 1.0 field of view is 7.915 mm, the image height of the MIC field of view is 8.100 mm, the FOV in the diagonal direction of the 1.0 field of view is 84.78°, and the FOV in the diagonal direction of the MIC field of view is 86.34°, and the imaging optical lens 30 satisfies the design requirements of being compact, having a wide angle, and having sufficient correction for aberrations, and has excellent optical characteristics.
[0075] (Fourth embodiment) The meanings of the symbols in the fourth embodiment are the same as those in the first embodiment.
[0076] Tables 7 and 8 show design data for the imaging optical lens 40 according to the fourth embodiment of the present invention.
[0077] [Table 7]
[0078] Table 8 shows the aspheric surface data of each lens in the imaging optical lens 40 according to the fourth embodiment of the present invention.
[0079] [Table 8]
[0080] 14 and 15 are schematic diagrams showing the axial chromatic aberration and chromatic aberration of magnification of light with wavelengths of 656 nm, 588 nm, 546 nm, 486 nm, and 436 nm, respectively, after passing through the imaging optical lens 40 according to the fourth embodiment. Fig. 16 is a schematic diagram showing the curvature of field and distortion of light with a wavelength of 546 nm after passing through the imaging optical lens 40 according to the fourth embodiment, where the curvature of field S in Fig. 16 is the curvature of field in the sagittal direction and T is the curvature of field in the tangential direction.
[0081] In this embodiment, the entrance pupil diameter ENPD of the imaging optical lens 40 is 4.868 mm, the image height IH of the 1.0 field of view is 8.000 mm, the image height of the MIC field of view is 8.290 mm, the FOV in the diagonal direction of the 1.0 field of view is 84.97°, and the FOV in the diagonal direction of the MIC field of view is 87.18°, and the imaging optical lens 40 satisfies the design requirements of being compact, having a wide angle, and having sufficient correction for aberrations, and has excellent optical characteristics.
[0082] Table 9 shows various numerical values in each of the first, second, third and fourth embodiments and values corresponding to parameters defined by conditional expressions.
[0083] [Table 9]
[0084] It will be understood by those skilled in the art that the above embodiments are specific embodiments for realizing the present invention, and in actual applications, various changes in form and details are possible without departing from the spirit and scope of the present invention.
Claims
1. An imaging optical lens, comprising: the imaging optical lens is composed of an aperture stop and seven lenses, the seven lenses being, 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 positive refractive power, a fifth lens having negative refractive power, a sixth lens having positive refractive power, and a seventh lens having negative refractive power; the first lens has an object side surface that is convex on the paraxial line and an image side surface that is concave on the paraxial line, the second lens has an object side surface that is convex on the paraxial line and an image side surface that is concave on the paraxial line, the third lens has an object side surface that is concave on the paraxial line and an image side surface that is concave on the paraxial line, the fourth lens has an object side surface that is convex on the paraxial line, the fifth lens has an object side surface that is convex on the paraxial line and an image side surface that is concave on the paraxial line, the sixth lens has an object side surface that is convex on the paraxial line and an image side surface that is convex on the paraxial line, and the seventh lens has an object side surface that is convex on the paraxial line and an image side surface that is concave on the paraxial line, an imaging optical lens, characterized in that the following conditional expressions (1) to (7) are satisfied: f is a focal length of the imaging optical lens, f1 is a focal length of the first lens, f2 is a focal length of the second lens, f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, f5 is a focal length of the fifth lens, f6 is a focal length of the sixth lens, f7 is a focal length of the seventh lens, d0 is an axial distance from the aperture stop to the object-side surface of the first lens, d1 is an axial thickness of the first lens, R9 is a paraxial central radius of curvature of the object-side surface of the fifth lens, R10 is a paraxial central radius of curvature of the image-side surface of the fifth lens, R12 is a paraxial central radius of curvature of the image-side surface of the sixth lens, R13 is a paraxial central radius of curvature of the object-side surface of the seventh lens, and R14 is a paraxial central radius of curvature of the image-side surface of the seventh lens. -18.000≦f1 / f+f2 / f+f3 / f≦-8.000 (1) -1.800≦f4 / f+f5 / f+f6 / f+f7 / f≦-0.600 (2) −0.080≦d0 / d1≦−0.050 (3) −8.000≦R12 / f6≦−2.500 (4) −1.000≦f4 / f5≦−0.500 (5) 1.700≦(R9+R10) / f≦2.600 (6) 2.000≦R13 / R14≦6.000 (7)
2. The imaging optical lens according to claim 1 , wherein the following conditional expression (8) is satisfied: -15.000≦f1 / f+f2 / f+f3 / f≦-9.000 (8)
3. The imaging optical lens according to claim 1 , wherein the following conditional expression (9) is satisfied: -1.500≦f4 / f+f5 / f+f6 / f+f7 / f≦-0.700 (9)
4. 2. The imaging optical lens according to claim 1, wherein the following conditional expression (10) is satisfied when an axial distance between an image-side surface of the fourth lens and an object-side surface of the fifth lens is d8 and an optical length of the imaging optical lens is TTL: 0.065≦d8 / TTL≦0.120 (10)
5. The imaging optical lens according to claim 1 , wherein the first lens is made of a glass material.
6. An imaging optical lens, comprising: the imaging optical lens is composed of an aperture stop and seven lenses, the seven lenses being, 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 positive refractive power, a fifth lens having negative refractive power, a sixth lens having positive refractive power, and a seventh lens having negative refractive power; the first lens has an object side surface that is convex on the paraxial line and an image side surface that is concave on the paraxial line, the second lens has an object side surface that is convex on the paraxial line and an image side surface that is concave on the paraxial line, the third lens has an object side surface that is concave on the paraxial line and an image side surface that is concave on the paraxial line, the fourth lens has an object side surface that is convex on the paraxial line, the fifth lens has an object side surface that is convex on the paraxial line and an image side surface that is concave on the paraxial line, the sixth lens has an object side surface that is convex on the paraxial line and an image side surface that is convex on the paraxial line, and the seventh lens has an object side surface that is convex on the paraxial line and an image side surface that is concave on the paraxial line, The focal length of the imaging optical lens is f, the focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the focal length of the sixth lens is f6, the focal length of the seventh lens is f7, the axial distance from the aperture stop to the object side surface of the first lens is d0, the axial thickness of the first lens is d1, the central radius of curvature of the object side surface of the first lens in the paraxial direction is R1, an imaging optical lens that satisfies the following conditional expressions (1) to (3) and (11) to (13): R2 is a central radius of curvature of the image-side surface on the paraxial axis, R13 is a central radius of curvature of the object-side surface of the seventh lens on the paraxial axis, R14 is a central radius of curvature of the image-side surface of the seventh lens on the paraxial axis, Σd is a sum of on-axis thicknesses of the first lens to the seventh lens, and ΣD is a sum of on-axis lengths of air gaps between any two adjacent lenses among the first lens to the seventh lens. -18.000≦f1 / f+f2 / f+f3 / f≦-8.000 (1) -1.800≦f4 / f+f5 / f+f6 / f+f7 / f≦-0.600 (2) −0.080≦d0 / d1≦−0.050 (3) 2.600≦f1 / R1+f1 / R2≦4.800 (11) 0.600≦(R13+R14) / f≦2.600 (12) 0.600≦ΣD / Σd≦0.950 (13)
7. The imaging optical lens according to claim 6 , which satisfies the following conditional expression (8): -15.000≦f1 / f+f2 / f+f3 / f≦-9.000 (8)
8. The imaging optical lens according to claim 6, which satisfies the following conditional expression (9): -1.500≦f4 / f+f5 / f+f6 / f+f7 / f≦-0.700 (9)
9. The imaging optical lens according to claim 6 , which satisfies the following conditional expression (14): 3.400≦f1 / R1+f1 / R2≦4.000 (14)
10. The imaging optical lens according to claim 6 , which satisfies the following conditional expression (15): 0.700≦(R13+R14) / f≦2.200 (15)
11. The imaging optical lens according to claim 6 , which satisfies the following conditional expression (16): 0.630≦ΣD / Σd≦0.920 (16)
12. 7. The imaging optical lens according to claim 6, wherein the following conditional expression (17) is satisfied when a composite focal length of the first lens and the second lens is f12 and a central radius of curvature of a paraxial image-side surface of the second lens is R4: -3.000≦f12 / (R1-R4)≦-1.300 (17)
13. The imaging optical lens according to claim 12, which satisfies the following conditional expression (18): -2.600≦f12 / (R1-R4)≦-1.500 (18)
14. The imaging optical lens according to claim 6 , which satisfies the following conditional expression (19): 0.007≦d0 / (R1-R2)≦0.020 (19)
15. The imaging optical lens according to claim 14, which satisfies the following conditional expression (20): 0.008≦d0 / (R1-R2)≦0.018 (20)
16. The imaging optical lens according to claim 6 , wherein the first lens is made of a glass material.